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COMPUTER OPERATOR AND, PROGRAMMING ASSISTANT, NSQF LEVEL - 4, , 1ST Semester, TRADE THEORY, SECTOR: IT & ITES, , DIRECTORATE GENERAL OF TRAINING, MINISTRY OF SKILL DEVELOPMENT & ENTREPRENEURSHIP, GOVERNMENT OF INDIA, , NATIONAL INSTRUCTIONAL, MEDIA INSTITUTE, CHENNAI, Post Box No. 3142, CTI Campus, Guindy, Chennai - 600 032, (i), , Copyright @ NIMI Not to be Republished
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COMPUTER OPERATOR AND, PROGRAMMING ASSISTANT, NSQF LEVEL - 4, , 1ST Semester, TRADE THEORY, SECTOR: IT & ITES, , DIRECTORATE GENERAL OF TRAINING, MINISTRY OF SKILL DEVELOPMENT & ENTREPRENEURSHIP, GOVERNMENT OF INDIA, , NATIONAL INSTRUCTIONAL, MEDIA INSTITUTE, CHENNAI, Post Box No. 3142, CTI Campus, Guindy, Chennai - 600 032, (i), , Copyright @ NIMI Not to be Republished
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COMPUTER OPERATOR AND, PROGRAMMING ASSISTANT, NSQF LEVEL - 4, , 1ST Semester, TRADE THEORY, SECTOR: IT & ITES, , DIRECTORATE GENERAL OF TRAINING, MINISTRY OF SKILL DEVELOPMENT & ENTREPRENEURSHIP, GOVERNMENT OF INDIA, , NATIONAL INSTRUCTIONAL, MEDIA INSTITUTE, CHENNAI, Post Box No. 3142, CTI Campus, Guindy, Chennai - 600 032, (i), , Copyright @ NIMI Not to be Republished
Page 4 : Sector, , : IT & ITES, , Duration : 1 - Year, Trade, , Copyright, , : Computer Operator and Programming Assistant 1st Semester - Trade Theory, NSQF level 4, , 2018 National Instructional Media Institute, Chennai, , First Edition :, Second Edition :, , September 2018, December 2018, , Copies : 1,000, Copies :1,000, , Rs. 255 /-, , All rights reserved., No part of this publication can be reproduced or transmitted in any form or by any means, electronic or mechanical, including, photocopy, recording or any information storage and retrieval system, without permission in writing from the National, Instructional Media Institute, Chennai., , Published by:, NATIONAL INSTRUCTIONAL MEDIA INSTITUTE, P. B. No.3142, CTI Campus, Guindy Industrial Estate,, Guindy, Chennai - 600 032., Phone : 044 - 2250 0248, 2250 0657, 2250 2421, Fax : 91 - 44 - 2250 0791, email :
[email protected],
[email protected], Website: www.nimi.gov.in, (ii), , Copyright @ NIMI Not to be Republished
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FOREWORD, , The Government of India has set an ambitious target of imparting skills to 30 crores people, one out of every, four Indians, by 2020 to help them secure jobs as part of the National Skills Development Policy. Industrial, Training Institutes (ITIs) play a vital role in this process especially in terms of providing skilled manpower., Keeping this in mind, and for providing the current industry relevant skill training to Trainees, ITI syllabus, has been recently updated with the help of Mentor Councils comprising various stakeholder's viz. Industries,, Entrepreneurs, Academicians and representatives from ITIs., The National Instructional Media Institute (NIMI), Chennai, has now come up with instructional material to, suit the revised curriculum for Computer Operator and Programming Assistant Trade Theory 1st, Semester in IT & ITES Sector . The NSQF Level - 4 Trade Theory will help the trainees to get an international, equivalency standard where their skill proficiency and competency will be duly recognized across the globe, and this will also increase the scope of recognition of prior learning. NSQF Level - 4 trainees will also get, the opportunities to promote life long learning and skill development. I have no doubt that with NSQF Level, - 4 the trainers and trainees of ITIs, and all stakeholders will derive maximum benefits from these IMPs and, that NIMI's effort will go a long way in improving the quality of Vocational training in the country., The Executive Director & Staff of NIMI and members of Media Development Committee deserve appreciation, for their contribution in bringing out this publication., Jai Hind, , RAJESH AGGARWAL, , Director General/ Addl. Secretary, Ministry of Skill Development & Entrepreneurship,, Government of India., , New Delhi - 110 001, , (iii), , Copyright @ NIMI Not to be Republished
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PREFACE, The National Instructional Media Institute (NIMI) was established in 1986 at Chennai by then Directorate, General of Employment and Training (D.G.E & T), Ministry of Labour and Employment, (now under Directorate, General of Training, Ministry of Skill Development and Entrepreneurship) Government of India, with technical, assistance from the Govt. of the Federal Republic of Germany. The prime objective of this institute is to, develop and provide instructional materials for various trades as per the prescribed syllabi under the Craftsman, and Apprenticeship Training Schemes., The instructional materials are created keeping in mind, the main objective of Vocational Training under, NCVT/NAC in India, which is to help an individual to master skills to do a job. The instructional materials are, generated in the form of Instructional Media Packages (IMPs). An IMP consists of Theory book, Practical, book, Test and Assignment book, Instructor Guide, Audio Visual Aid (Wall charts and Transparencies) and, other support materials., The trade practical book consists of series of exercises to be completed by the trainees in the workshop., These exercises are designed to ensure that all the skills in the prescribed syllabus are covered. The trade, theory book provides related theoretical knowledge required to enable the trainee to do a job. The test and, assignments will enable the instructor to give assignments for the evaluation of the performance of a trainee., The wall charts and transparencies are unique, as they not only help the instructor to effectively present a, topic but also help him to assess the trainee's understanding. The instructor guide enables the instructor to, plan his schedule of instruction, plan the raw material requirements, day to day lessons and demonstrations., IMPs also deals with the complex skills required to be developed for effective team work. Necessary care, has also been taken to include important skill areas of allied trades as prescribed in the syllabus., The availability of a complete Instructional Media Package in an institute helps both the trainer and, management to impart effective training., The IMPs are the outcome of collective efforts of the staff members of NIMI and the members of the Media, Development Committees specially drawn from Public and Private sector industries, various training institutes, under the Directorate General of Training (DGT), Government and Private ITIs., NIMI would like to take this opportunity to convey sincere thanks to the Directors of Employment & Training, of various State Governments, Training Departments of Industries both in the Public and Private sectors,, Officers of DGT and DGT field institutes, proof readers, individual media developers and coordinators, but for, whose active support NIMI would not have been able to bring out this materials., , R. P. DHINGRA, EXECUTIVE DIRECTOR, , Chennai - 600 032, , (iv), , Copyright @ NIMI Not to be Republished
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INTRODUCTION, TRADE THEORY, The manual of trade theory consists of theorectical information for the First Semester couse of the COPATrade., The contents are sequenced accoring to the practical exercise contained in the manual on Trade practical., Attempt has been made to relate the theortical aspects with the skill covered in each exercise to the extent, possible. This co-relation is maintained to help the trainees to develop the perceptional capabilities for, performing the skills., The Trade Theory has to be taught and learnt along with the corresponding exercise contained in the manual, on trade practical. The indicating about the corresponding practical exercise are given in every sheet of this, manual., It will be preferable to teach/learn the trade theory connected to each exercise atleast one class before, performing the related skills in the system lab. The trade theory is to be treated as an integrated part of each, exercise., The material is not the purpose of self learning and should be considered as supplementary to class room, instruction., TRADE PRACTICAL, The trade practical manual is intented to be used in workshop . It consists of a series of practical exercies to, be completed by the trainees during the First Semester course of the COPA trade supplemented and, supported by instructions/ informations to assist in performing the exercises. These exercises are designed, to ensure that all the skills in the prescribed syllabus are covered., The manual is divided into twelve modules to maintain completancy of leaning process in a stipulated time, basis., The skill training in the computer lab is planned through a series of practical exercises centred around some, practical project. However, there are few instance where the individual exercise does not form a part of project., While developing the practical manual a sincere effort was made to prepare each exercise which will be easy, to understand and carry out even by below average traninee. However the development team accept that there, if a scope for further improvement. NIMI, looks forward to the suggestions from the experienced training faculty, for improving the manual., , (vi), , Copyright @ NIMI Not to be Republished
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CONTENTS, Lesson No., , Title of the Lesson, , Page No., , Module 1: Safe working practices, 1.1.01 &1.1.02, , Electrical safety, , 1, , 1.1.03 & 1.1.04, , Safety practices, fire extinguishers, , 2, , Module 2: Introduction to computer components, 1.2.05, , Introduction to computers, , 7, , 1.2.06, , Introduction to CPU architecture and mother board, , 17, , Module 3: Windows operating system, 1.3.07 -1.3.11, , Windows operating system, , 25, , 1.3.12, , Handling printers, , 33, , Module 4: Computer basics and software installation, 1.4.13, , CMOS setup and windows installation, , 36, , 1.4.14 & 1.4.15, , CMOS setup and windows installation, , 38, , 1.4.16, , Troubleshooting computer, , 42, , 1.4.17, , Application Softwares, , 47, , 1.4.18 & 1.4.19, , Bluetooth devices, , 49, , 1.4.20, , DVDs, CDs and burning DVDs, , 51, , Module 5: Dos & LInux operating systems, 1.5.21, , Comand line interface with DOS, , 53, , 1.5.22, , Methods to display the contents of a text file, , 56, , 1.5.23, , Introduction to Linux operating system, , 60, , 1.5.24 - 1.5.26, , Handling commands and various editors, , 63, , 1.5.27 - 1.5.28, , Managing files and directories, , 80, , Module 6: Word Processing Software, 1.6.29, , MS word 2010 Theory, , 113, , 1.6.30 - 1.6.37, , Creating a file, save and other options, , 117, , 1.6.38, , Typing practice using open source typing tutor tools, , 123, , (vii), , Copyright @ NIMI Not to be Republished
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Lesson No., , Title of the Lesson, , Page No., , Module 7: Spread sheet Application, 1.7.39 - 1.7.41, , Introduction to MS - Excel 2010, , 124, , 1.7.42 - 1.7.46, , Functions and formulas in MS- Excel 2010, , 133, , 1.7.47 - 1.7.48, , Data validations and Table management in Ms Excel 2010, , 138, , Module 8: Image Editing, presentations, 1.8.49 - 1.8.57, , Image editing, presentations, , 145, , Module 9: Database Management Systems, 1.9.58 - 1.9.61, , Concepts of data and Databases, , 152, , 1.9.62 - 1.9.66, , Forms, quires, and reports in access, , 163, , Module 10: Networking concepts, 1.10.67 - 1.10.69, , Concepts of network and internet, , 169, , 1.10.70, , Introduction to TCP/IP, , 188, , 1.10.71 & 1.10.72, , Transmission media and network components, , 190, , 1.10.73A, , Computer name and workgroup, , 197, , 1.10.73B, , Concept of proxy server, , 200, , 1.10.74, , Video conferencing, , 202, , 1.10.75, , Network security, , 203, , Module 11: Internet Concepts, 1.11.76 & 1.11.77, , E- mail, , 205, , 1.11.78, , Chatting,video chatting and using social network sites, , 209, , 1.11.79, , Explaining threats to computers connected to Internet & process, , 210, , 1.11.80 & 1.11.81, , Outlook Express & Google+, , 213, , Module 12: Designing Static Webpages, 1.12.82 - 1.12.92, , Web designing, , 214, , 1.12.93, , Introduction to CMS and web authoring tools, , 237, , (viii), , Copyright @ NIMI Not to be Republished
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LEARNING / ASSESSABLE OUTCOME, On completion of this book you shall be able to, • Install and setup operating system and related software in a, computer., • Create, format and edit document using word processing application software., • Create, edit and develop a workbook by using spreadsheet application software., • Create and customize slides for presentation., • Create and manage database file by using MS Access, • Install, setup/ configure, troubleshoot and secure computer network including Internet., • Develop static webpages using HTML., , (ix), , Copyright @ NIMI Not to be Republished
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SYLLABUS, First Semester, Week, No., 1., , Duration: Six Month, , Ref. Learning, Outcome, , •, , Apply safe working, practices, , • Install and setup, , operating system, and related software, in a computer., , Professional Skills, (Trade Practical), with Indicative hours, , Safe working practices, Safe working practices, • Scope of the COPA trade., 1. Visit COPA Lab. of the institutes and, locate the electrical connections with • Safety rules and safety signs., computer system setup (6 hrs), • Types and working of fire, 2. Identifying safety symbols and, extinguishers., hazard identification.(4 Hrs), Introduction to Computer, 3. Practice safe methods of fire fighting in, components, case of electrical fire. (4 hrs), • Introduction to computer, 4. Use of fire extinguishers. (4 Hrs), system. Concepts of hardward, Computer components, and Software., 5. Identify computer peripherals and, •, Function of motherboard, internal components of a disassembled, components and various, desktop computer. (6 Hrs), processors., 6. Assemble components of desktop, computer. (6 Hrs), • Various Input / Output devices, in use and their features., , 2., , • Install and setup, , Using Windows Operating System, 7. Practice on Windows interface, and navigating windows. (9 Hrs), 8. Practice on managing files and, folders using removable drives. (6 Hrs), 9. Customize the desktop settings, and manage user accounts. (6 Hrs), 10. View system properties and control, panel details. (6 Hrs), 11. Work with keyboard shortcut commands., (6 Hrs), 12. Print and scan document using different, commands.(3 Hrs), , 3., , • Install and setup, , Computer basics and Software, Installation, 13. View the BIOS settings and their, modifications. (3 Hrs), 14. Install Windows OS (5 Hrs), 15. Format Hard Disk and create, partition (3 Hrs), 16. Identify and rectify common, hardware and software issues, during OS installation. (4 Hrs), 17. Install necessary application, software for Windows i.e. Office, Package, PDF Reader, Media, Player etc. (5 Hrs), 18. Configure Bluetooth and wi-fi, settings. (3 Hrs), 19. Install Drivers for printer, scanner,, webcam and DVD etc. (4 Hrs), 20. Burn data, video and audio files on, CD/DVD using application, software. (3 Hrs), , operating system, and related software, in a computer., , operating system and, and related software, in a computer., , Professional Knowledge, (Trade Theory), , COPA 1st semester, , Introduction Windows, Operating System, • Introduction to operating, System, • Main features of Windows, OS, • Concept of various shortcut, commands., , Computer basics and Software, Installation, • Introduction to the booting, process., • Introduction to various, types of memories and their, features., • Basic Hardware and, software issues and their, solutions., • Usage of Application, software and Antivirus., , Copyright @ NIMI Not to be Republished
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• Install and, , DOS Command Line Interface & Linux, Operating Systems, 21. Use basic DOS commands for directory listing (10 hrs), 22. Manage files and folders using DOS commands (6 hrs), 23. Install Linux operating system.(6 Hrs), 24. Install necessary application software for Linux i.e., Office Package, PDF Reader, MediaPlayer etc. (6 Hrs), 25. Use Basic Linux commands for directory listing, file, and folder management, password etc. (10Hrs), 26. Use the Linux GUI for file and folder management,, exploring the system etc. (10 Hrs), 27. Customize desktop settings and manage user, accounts in Linux. (6 Hrs), 28. View system properties and manage system setting, in Linux (6 Hrs), , 6-8, , Create, format, and edit, document using, word, processing, application, software., , Word Processing, Using Word Processing Software, 29. Open MS Word and familiarise with basic word Software, components. (3 Hrs), • Introduction to the various, 30. Practice creating, saving and renaming of word, applications in MS office., documents.(3 Hrs), • Introduction to Word, 31. Edit document using basic formatting tools. (8 Hrs), features,, 32. Practice Inserting and formatting tables and other, Office button, toolbars., objects. (12 Hrs), • Creating, saving and, 33. Work with Page layout settings and printing, formatting, documents. (6 Hrs), and printing documents, 34. Use templates, autocorrect tools, and record and, using Word., execute a macro. (6 Hrs), 35. Use Mail merge tool. Use conditional Mail Merge, • Working with objects,, macro, mail merge,, External Data Source. Practice Letters, Label &, templates and other tools, Envelop printing using Mail Merge (10 Hrs)., in Word., 36. Use Table of Context, Indexing, Hyperlink, Bookmark,, Comment, equation,symbols,citation, crossreference,, footnote, translate, synonyms, thesaurus, spell, check & grammer, compare etc. ( 6 Hrs ), 37. Practice Typing using open source tutor. (24 Hrs), 38. Practice of using shortcut keys and use Open Office, as word processor. (12 Hrs), , 9 - 11, , • Create,, , 4-5, , setup OS, and related, software in a, computer., , Introduction to DOS, Command, Line Interface & Linux, Operating, Systems, • Introduction to basic DOS, Internal and External, Commands., • Introduction to Open, Source Software., • Introduction to Linux, Operating System features,, structure,, files, and, processes., • Basic Linux commands., , Using Spread Sheet Application, Spread Sheet Application, 39. Open MS Excel and familiarise with basic application • Introduction to Excel, format,, components. (4 Hrs), edit and, features and Data Types., 40., Practice, create, save and format excel sheets. (9 Hrs), develop, • Cell referencing and, a workbook by 41. Use absolute and relative referencing, linking sheets,, linking, conditional formatting etc. (9 Hrs), using, Sheets., spreadsheet 42. Practice Excel functions of all major categories i.e. • Introduction to various, Financial, Logical, Text, date & time, Lookup, Math,, application, functions in all categories, Statistical etc. (12 Hrs), software., of Excel., 43. Use various data types in Excel, sorting, filtering and, • Concepts of sorting,, validating data. (8 Hrs), 44. Create and format various static and dynamic charts., filtering, (10 Hrs), and validating data., 45. Practice Importing & exporting excel data. (4 Hrs), • Analyzing data using, 46. Perform data analysis using “what if” tools and Pivot, charts, data tables, pivot, Table and record and execute a macro. (10 Hrs), tables, goal seek and, 47. Modify Excel page setup and printing and use open, scenarios., office as Spreadsheet application. (4 Hrs), 48. Execute simple projects using Excel & Word. (20 Hrs), , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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12 - 13, , Create and, customize, slides for, presentation., , 14 - 15, , Create and, manage, database, file by, using MS, Access., , 16 - 17, , Install,, setup/, configure,, troubleshoot, and secure, computer, network, including, Internet., , Image editing and creating, Presentations, 49. Use Windows Paint or image editing, software like Open Office Draw, GIMP,, IrfanView or a similar tool. (6 Hrs), 50. Perform Image editing using open, source applications. (12 Hrs), 51. Open power point presentation, and familiarise with basic, application components. (6 Hrs), 52. Create Slide shows, Insert picture, and theme. (6 Hrs), 53. Add new slide, format text, link with word, and excel documents. (5 Hrs), 54. Practice animating slide transitions and, objects. (4 Hrs), 55. Create slide shows by inserting audio &, video and sync with presentation. (6 Hrs), 56. Modify slide page setup and print, the slides. (3 Hrs), 57. Create a simple presentation, project using open office. (12 Hrs), Database Management with MS Access, 58. Create database and design a simple tables, in Access. (6 Hrs), 59. Practice enforcing integrity constraints and, modify properties of tables and fields. (6, Hrs), 60. Create relationships and join tables. (6 Hrs), 61. Create and format Forms. (6 Hrs), 62. Create simple queries with various criteria, and calculations. (12 Hrs), 63. Create Simple update, append, make table,, delete and crosstab queries. (9 Hrs), 64. Modify form design with controls, macros, and events. (6 Hrs), 65. Import and export data to/from Access and, create and format types of reports. (6 Hrs), 66. Compress and Encrypt databases. (3 Hrs), , Image editing, Presentations, • Introduction to Open Office., • Introduction to the, properties and editing of, images., • Introduction to different, formats of images and their, uses., • Introduction to Power Point, and its advantages., • Creating Slide Shows., • Fine tuning the, presentation and good, presentation technique., , Database Management Systems, • Concepts of Data and Databases., • Overview of popular databases,, RDBMS, OODB and NOSQL., • Rules for designing good tables., Integrity rules and constraints in, a table., • Relationships in tables., • Introduction to various types of, Queries and their uses., • Designing Access Reports and, Forms., • Introduction to macros, designer, objects controls, their properties, and behaviour., , Configuring and using Network, Networking Concepts, 67. View Network connections. (3 Hrs), • Introduction to Computer Networks,, 68. Connect a computer to a n/w and share, Necessity and Advantages., Devices i.e. Printers, files, folders and, • Client Server and peer to Peer, drives. (6 Hrs), networking concepts., 69. Work with various Network devices,, •, Concept of Proxy Server and proxy, connectors/cables. Create straight/cross, firewall server., cable and punch a UTP cable in the patch, • Concept of DHCP Server., socket and test the connectivity. (6 Hrs), 70. Practice IP Addressing and Subnet masking • Introduction to LAN, WAN and MAN., for IPV4/ IPV6 and pinging to test networks. • Network topologies. Network, (6 Hrs), components, viz. Modem, Hub,, 71. Configure Hub and Switch. (6 Hrs), Switch, Router,Bridge, Gateway etc., 72. Set up and configure wired and wireless, • Network Cables, Wirelessnetworks, LAN in a Computer Lab within at least three, and Blue Tooth technology., computers. Use patch panel & I/O Box for, •, Concept of ISO - OSI 7 Layer Model., wired LAN and installing & configuring, Internet connection in a single PC and in a • Overview of Network protocols, Viz.TCP/IP, FTP, Telnet etc., LAN. (12 Hrs), COPA1st semester, , Copyright @ NIMI Not to be Republished
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73. Setup a proxy server/DHCP Server with firewall.(9 Hrs), 74. Setup video conferencing using open source s/w(6 Hrs), 75. Use various tools (by open source /free) for network, troubleshooting, maintenance and security for both, Wired and Wireless(6 Hrs), 18, , • Concept of Logical and, , Physical Addresses,, Subnetting and Classes of, Networks., , Using Internet, Install,, Internet Concepts, 76. Browse the Internet for information (use at least 3 • Introduction to www,, setup/, popular browsers). (3 Hrs), configure,, Concept of Internet, Web, troubleshoot 77. Create and use e-mail for communication with, Browsers, internet servers, attachment, priority setting, address book. (3 Hrs), and secure, and search engines., 78. Communicate with text, video chatting and social, computer, •, Concepts of Domain naming, networking sites. (6 Hrs), network, Systems and E mail, 79. Use online dictionary, translation software, storage, including, communication., space, share files with e-mail links, download manager,, Internet., •, Introduction to video chatting, download & upload YouTube files, google map & earth, tools and Social Networking, etc. Update windows & other software. (6 Hrs), concepts., 80. Configure Outlook, mail service in mobile phones. Use, tools like Skype, Google+ etc. (6 Hrs), 81. Browser setting for Bookmark, cookies, favourites and, pop ups, default website, trusted site,restricted site,, content, history and advanced setup. (6 Hrs ), , Web Design Concepts, Designing Static Web Pages, 19-21 Develop, 82. Practice with basic HTML elements (e.g. head, title, • Concepts of Static and, static, body), tag and attributes. (3 Hrs), Dynamic Web pages., web pages, 83. Design simple web page with text, paragraph and line • Introduction to HTML and, using, break usingHTML tags. (5 Hrs), HTML., various tags in HTML., 84. Format text, change background colour and insert, • Concepts of different, pictures in web page. (6 Hrs), controls used in Web Pages., 85. Design simple web page with tables and lists. (6 Hrs), 86. Use marquees, hyperlinks and mailto link in designing • Concepts of CSS and, applying CSS to HTML., web pages.(6 Hrs), •, Introduction to open source, 87. Create frames, add style and design layout. (10 Hrs), CMS viz, Joomla, Word, 88. Insert text, check and combo box in web page. (6 Hrs), press etc. and Web, 89. Design web page using password field, submit button,, authoring tools viz., reset button and radio button etc. (6 Hrs), Kompozer, Front Page etc., 90. Design a web page adding flash file, audio and video, files. (10 Hrs), • Concept of good web page, 91. Design web page with forms and form controls using, designing techniques., HTML tags.(8 Hrs), 92. Create web page using Cascading Style Sheet (CSS)., (12 Hrs), 93. Use WYSIWYG (Kompozer) web design tools to, design and edit web pages with various styles. (12Hrs), 22-23 Industrial Visit/Project work, 1. Create a simple web site of at least 5 web pages which will include Images, tables, charts, lists and, hyperlink on any topic like Student Information System, Book Store, and Organisations etc., OR, 2. Setup and configure a LAN using at least 3 computers connected with wire and 3 computers connected, with wireless and secure it.), 24-25, 26, , Revision, Examination, , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.01 &1.1.02, , Electrical safety, Objective : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire., The severity of an electric shock will depend on the level of, current which passes through the body and the length of, time of contact. Do not delay, act at once. Make sure that, the electric current has been disconnected., , If the casualty is unconscious but is breathing, loosen the, clothing about the neck, chest and waist and place the, casualty in the recovery position.( Fig 3), , If the casualty is still in contact with the supply - break the, contact either by switching off the power, removing the plug, or wrenching the cable free. If not, stand on some insulating, material such as dry wood, rubber or plastic, or using, whatever is at hand to insulate yourself and break the, contact by pushing or pulling the person free. (Figs 1 & 2), If you remain un-insulated, do not touch the victim with your, bare hands until the circuit is made dead or person is, moved away from the equipment., , Keep a constant check on the breathing and pulse rate., Keep the casualty warm and comfortable. (Fig 4), Send for help., Do not give an unconscious person anything by, mouth., Do not leave an unconscious person unattended., If the casualty is not breathing - Act at once - don’t waste, , If the victim is aloft, measures must be taken to prevent him, from falling or atleast make him fall safe., Electric burns on the victim may not cover a big area but, may be deep seated. All you can do is to cover the area, with a clean, sterile dressing and treat for shock. Get, expert help as quickly as possible., , Copyright @ NIMI Not to be Republished, , 1
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.03 & 1.1.04, , Safety practice - fire extinguishers, Objectives : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire, • distinguish the different types of fire extinguishers, • determine the correct type of fire extinguisher to be used based on the class of fire, • describe the general procedure to be adopted in the event of a fire., Fire is the burning of combustible material. A fire in an, unwanted place and on an unwanted occasion and in an, uncontrollable quantity can cause damage or destroy, property and materials. It might injure people, and, sometimes cause loss of life as well. Hence, every effort, must be made to prevent fire. When a fire outbreak is, discovered, it must be controlled and extinguished by, immediate corrective action., Is it possible to prevent fire? Yes, fire can be prevented by, eliminating anyone of the three factors that causes fire., The following are the three factors that must be present in, combination for a fire to continue to burn. (Fig 1), , Accumulation of combustible refuse (cotton waste soaked, with oil, scrap wood, paper, etc.) in odd corners are a fire, risk. Refuse should be removed to collection points., The cause of fire in electrical equipment is misuse or, neglect. Loose connections, wrongly rated fuses, overloaded, circuits cause overheating which may in turn lead to a fire., Damage to insulation between conductors in cables causes, fire., Clothing and anything else which might catch fire should be, kept well away from heaters. Make sure that the heater is, shut off at the end of the working day., Highly flammable liquids and petroleum mixtures (thinner,, adhesive solutions, solvents, kerosene, spirit, LPG gas, etc.) should be stored in the flammable material storage, area., Blowlamps and torches must not be left burning when they, are not in use., Extinguishing fires: Fires are classified into four types in, terms of the nature of fuel., , Fuel: Any substance, liquid, solid or gas will burn, if there, is oxygen and high enough temperatures., Heat: Every fuel will begin to burn at a certain temperature., It varies and depends on the fuel. Solids and liquids give off, vapour when heated, and it is this vapour which ignites., Some liquids do not have to be heated as they give off, vapour at normal room temperature say 150C, eg. petrol., Oxygen: Usually exists in sufficient quantity in air to keep, a fire burning., Extinguishing of fire: Isolating or removing any of these, factors from the combination will extinguish the fire. There, are three basic ways of achieving this., •, , Starving the fire of fuel removes this element., , •, , Smothering - ie. isolate the fire from the supply of, oxygen by blanketing it with foam, sand etc., , •, , Cooling - use water to lower the temperature. Removing, any one of these factors will extinguish the fire., , Different types of fires (Fig 2, Fig 3 Fig 4 & Fig 5) have to, be dealt with in different ways and with different extinguishing, agents., An extinguishing agent is the material or substance used, to put out the fire, and is usually (but not always) contained, in a fire extinguisher with a release mechanism for spraying, into the fire., It is important to know the right type of agent for extinguishing, a particular type of fire; using a wrong agent can make, things worse.There is no classification for ‘electrical fires’, as such, since these are only fires in materials where, electricity is present., , Preventing fires: The majority of fires begin with small, outbreaks which burn unnoticed until they have a secure, hold. Most fires could be prevented with more care and by, following some simple common sense rules., 2, , Copyright @ NIMI Not to be Republished
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Fuel, , Extinguishing, Most effective ie. cooling with water. Jets of water, should be sprayed on the base of the fire and then, gradually upwards., , Should be smothered. The aim is to cover the entire, surface of the burning liquid. This has the effect of, cutting off the supply of oxygen to the fire., Water should never be used on burning liquids., Foam, dry powder or CO2 may be used on this type, of fire., , Extreme caution is necessary in dealing with liquefied, gases. There is a risk of explosion and sudden, outbreak of fire in the entire vicinity. If an appliance, fed from a cylinder catches fire - shut off the supply, of gas. The safest course is to raise an alarm and, leave the fire to be dealt with by trained personnel., Dry powder extinguishers are used on this type of, fire., , Special powders have now been developed which, are capable of controlling and/or extinguishing this, type of fire., The standard range of fire extinguishing agents is, inadequate or dangerous when dealing with metal, fires., Fire on electrical equipment., Halon, Carbon dioxide, dry powder and vapourising, liquid (CTC) extinguishers can be used to deal with, fires in electrical equipment. Foam or liquid (eg., water) extinguishers must not be used on electrical, equipment under any circumstances., , IT & ITES : COPA - Related Theory for Exercise 1.01.01 & 1.01.02, , Copyright @ NIMI Not to be Republished, , 3
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Many types of fire extinguishers are available with different, extinguishing ‘agents’ to deal with different classes of fires., (Fig 1), , Dry powder extinguishers (Fig 4): Extinguishers fitted, with dry powder may be of the gas cartridge or stored, pressure type. Appearance and method of operation is the, same as that of the water-filled one. The main distinguishing feature is the fork shaped nozzle. Powders have been, developed to deal with class D fires., , Water-filled extinguishers: There are two methods of, operation. (Fig 2), , Carbon dioxide (CO2): This type is easily distinguished, by the distinctively shaped discharge horn. (Fig 5)., , •, , Gas cartridge type, , •, , Stored pressure type, , With both methods of operation the discharge can be, interruted as required, conserving the contents and, preventing unnecessary water damage., Foam extinguishers (Fig 3):These may be of stored, pressure or gas cartridge types. Always check the operating, instructions on the extinguisher before use., , Suitable for Class B fires. Best suited where contamination, by deposits must be avoided. Not generally effective in, open air., Always check the operating instructions on the container, before use. Available with different gadgets of operation, such as - plunger, lever, trigger etc., Halon extinguishers (Fig 6): These extinguishers may be, filled with carbon-tetrachloride and Bromochlorodifluoro, methene (BCF). They may be either gas cartridge or stored, pressure type., , Most suitable for, • flammable liquid fires, •, , running liquid fires., , Must not be used on fires where electrical equipment is, involved., , 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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They are more effective in extinguishing small fires involving, pouring liquids. These extinguishers are particularly suitable, and safe to use on electrical equipment as the chemicals, are electrically non-conductive., The fumes given off by these extinguishers are, dangerous, especially in confined space., The general procedure in the event of a fire:, •, , Raise an alarm., , •, , Turn off all machinery and power (gas and electricity)., , •, , Close the doors and windows, but do not lock or bolt, them. This will limit the oxygen fed to the fire and prevent, its spreading., , •, , Try to deal with the fire if you can do so safely. Do not, risk getting trapped., , •, , Anybody not involved in fighting the fire should leave, calmly using the emergency exits and go to the, designated assembly point. Failure to do this may, mean that some person being unaccounted for and, others may have to put themselves to the trouble of, searching for him or her at risk to themselves., , Practice on fire extinguishers, Objectives: At the end of this lesson you shall be able to, • state about the selection of the fire extinguishers according to the type of fire, • state the method of operation of the fire extinguisher, • explain how to extinguish the fire., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished, , 5
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PROCEDURE (Fig 1), , •, , •, , Alert people sorrounding by shouting fire, fire, fire when, observe the fire., , •, , Inform fire service or arrange to inform immediately., , •, , Open emergency exist and ask them to go away., , •, , Put “off” electrical power supply., , Aim the extinguisher nozzle or hose at the base of the, fire (this will remove the source of fuel fire) (Fig 4), , Don’t allow people to go nearer to the fire, •, , Analyze and identify the type of fire. Refer Table1., Table-1, Class ‘A’, , Wood, paper, cloth,, solid material, , Class ‘B’, , Oil based fire (grease,, gasoline, oil) liquefiable, gases, , Class ‘C’, , Gas and liquefiable, , Keep your self low, •, , Squeeze the handle lever slowly to discharge the agent, (Fig 5), , •, , Sweep side to side approximately 15 cm over the fuel, fire until the fire is put off (Fig 5), , gases, Class ‘D’, , Metals and electrical, equipment, , Assume the fire is ‘B; type (flammable liquifable solids), •, , Slect CO2 (Carbon di oxide) fire extinguisher., , •, , Locate and pickup, CO2 fire extinguisher. Click for its, expiry date., , •, , Break the seal (Fig 2), Fire extinguishers are manufactured for use, from the distance., Caution, • While putting off fire, the fire may flare up, • Do not be panick belong as it put off promptly., • If the fire doesn’t respond well after you have, used up the fire extinguisher move away yourself, away from the fire point., , •, , Pull the safety pin from the handle (Pin located at the, top of the fire extinguisher) (Fig 3), , • Do not attempt to put out a fire where it is, emitting toxic smoke leave it for the professionals., • Remember that your life is more important than, property. So don’t place yourself or others at risk., In order to remember the simple operation of the, extinguisher. Remember P.A.S.S. This will help, you to use the fire extinguisher., P for Pull, A for Aim, S for Squeeze, S for Sweep, , 6, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.2.05, COPA - Introduction to computer components, Introduction to computers, Objectives : At the end of this lesson you shall be able to, • define and classify computers, • list the advantages and limitations of computers, • list the applications of computer, • describe the voltages and currents in the computer., Computer - Definitions, , Fig 1, , A computer is an electronic machine, operating under, the control of instructions stored in its own memory that, can accept data (input), manipulate the data according, to specified rules (process), produce results (output), and, store the results for future use., Technically, a computer is a programmable machine., This means it can execute a list of programmed, instructions and respond to new instructions that it is, given., History of Computer, Charles babbbage’s machine, , The Analytical Engine had four parts. A mill, which was, the section which did the calculations, essentially the, CPU; the store, were the information was kept recorded,, essentially the memory; the reader, which would allow, data to be entered using punched cards, essentially the, keyboard, and the printer., Hence, Charles Babbage is considered as the "Father, of the Computer" as in fig-1., The generations of computers are characterized by a, major technological development that fundamentally, changed the way computers operate, resulting in, increasingly smaller, cheaper, more powerful and more, efficient and reliable devices. The various generations, of computers are listed below:, First Generation (1946-1954): In 1946 the digital, computer using electronic valves (Vacuum tubes) are, known as first generation computers. The first 'computer', to use electronic valves i.e. vacuum tubes. The high, cost of vacuum tubes prevented their use for main, memory. They stored information in the form of, propagating sound waves., The vacuum tube consumes a lot of power. These, computers were large in size and writing programs on, them was difficult. Some of the computers of this, generation were:, , CP110111, , The working principles of today's computers were, provided by an English mathematician Charles Babbage, around 1833's invented a machine called the "Analytical, Engine". A machine which could calculate and print tables, of functions using limited techniques., , Mark I :The IBM Automatic Sequence Controlled, Calculator (ASCC), called the Mark I by Harvard, University, was an electro-mechanical computer. Mark, I is the first machine to successfully perform a long, services of arithmetic and logical operation. Mark I is, the First Generation Computer., ENIAC: It was the first electronic computer built in 1946, at University of Pennsylvania, USA by John Eckert and, John Mauchy. It was named Electronic Numerical, Integrator and Calculator (ENIAC). The ENIAC was 3050 feet long, weighted 30 tons, contained 18,000 vacuum, tubes, 70,000 resisters, 10,000 capacitors and required, 150,000 watts of electricity. Today computer is many, times as powerful as ENIAC, still size is very small., EDVAC: It stands for Electronic Discrete Variable, Automatic Computer and was developed in 1950. The, concept of storing data and instructions inside the, computer was introduced here. This allowed much faster, operation since the computer had rapid access to both, data and instructions. The other advantage of storing, instruction was that computer could do logical decision, internally. The EDVAC was a binary serial computer, with automatic addition, subtraction, multiplication,, programmed division and automatic checking with an, ultrasonic serial memory., , Copyright @ NIMI Not to be Republished, , 7
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EDSAC: It stands for Electronic Delay Storage, Automatic Computer and was developed by M.V., Wilkes at Cambridge University in 1949. The EDSAC, is the first stored-program computer. The EDSAC, performed computations in the three millisecond range., It performed arithmetic and logical operations without, human intervention. The key to the success was in the, stored instructions which it depended upon solely for its, operation., , • Transistors were used instead of Vacuum Tube., • Processing speed is faster than First Generation, Computers (Micro Second), , • Smaller in Size (51 square feet), • The input and output devices were faster., , This machine marked the beginning of the computer, age., , Third Generation (1964-1977):By the development of a, small chip consisting of the capacity of the 300 transistors., These Integrated Circuits (IC)s are popularly known as, Chips., , UNIVAC-1: It stands for Universal Automatic, computer and it was the First commercial computer, developed by United States In 1951. The machine was, 25 feet by 50 feet in length, contained 5,600 tubes, 18,000, crystal diodes, and 300 relays. It utilized serial circuitry,, 2.25 MHz bit rate, and had an internal storage capacity, 1,000 words or 12,000 characters., , A single IC has many transistors, registers and capacitors, built on a single thin slice of silicon. So it is quite obvious, that the size of the computer got further reduced. Some, of the computers developed during this period were IBM360, ICL-1900, IBM-370, and VAX-750. Higher level, language such as BASIC (Beginners All purpose, Symbolic Instruction Code) was developed during this, period., , The UNIVAC was used for general purpose computing, with large amounts of input and output. The UNIVAC, was also the first computer to come equipped with a, magnetic tape unit and was the first computer to use, buffer memory., Limitations of First Generation Computer, Followings are the major drawbacks of First generation, computers., , Computers of this generation were small in size, low cost,, large memory and processing speed is very high. Very, soon ICs were replaced by LSI (Large Scale Integration), which consisted about 100 components., An IC containing about 100 components is called LSI as, in (Fig 2)., Features, , • They used valves or vacuum tubes as their main, electronic component., , • They were large in size, slow in processing and had, less storage capacity., , • They consumed lots of electricity and produced lots, of heat., , • Their computing capabilities were limited., • They were not so accurate and reliable., • They used machine level language for programming., • They were very expensive., Second Generation (1955-1964): The second-generation computer used transistors for CPU components, and ferrite cores for main memory&magnetic disks, for secondary memory. They used high-level languages, such as FORTRAN (1956), ALGOL (1960) & COBOL, (1960 - 1961). Input Output (I/O)processor was included, to control I/O operations., Manufacturing cost was also very low. Thus the size of, the computer got reduced considerably., It is in the second generation that the concept of Central, Processing Unit (CPU), memory, programming language, and input and output units were developed. Some of the, second generation computers are IBM 1620, IBM, 1401,CDC 3600., 8, , • They used Integrated Circuit (IC) chips in place of the, transistors., , • Semi conductor memory devices were used., • The size was greatly reduced, the speed of processing, was high, and they were more accurate and reliable., , • Large Scale Integration (LSI) and Very Large Scale, Integration (VLSI) were also developed., , • The mini computers were introduced in this generation., • They used high level language for programming., Fourth Generation (1978 - present): An IC containing, about 100 components is called LSI (Large Scale, Integration) and the one, which has more than 1000 such, components, is called as VLSI (Very Large Scale, Integration)., It uses large scale Integrated Circuits(LSIC) built on a single, silicon chip called microprocessors. Due to the, development of microprocessor it is possible to place, computer's centralprocessing unit(CPU) on single chip., These computers are called microcomputers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Later very large scale Integrated Circuits(VLSIC) replaced, LSICs. Thus the computer which was occupying a very, large room in earlier days can now be placed on a table., The personal computer (PC) that you see in your school, is a Fourth Generation Computer Main memory used fast, semiconductors chips up to 4 M bits size. Some of the, Fourth generation computers are IBM PC, AppleMacintosh, etc., , Fig 3, , Hard disks were used as secondary memory. Keyboards,, dot matrix printers etc. were developed. Operating System, (OS)-such as MS-DOS, UNIX, Apple's Macintosh were, available. Object oriented language, C++ etc were, developed., Features, , • They used Microprocessor (VLSI) as their main, switching element., , • They are also called as micro computers or personal, computers., , • Their size varies from desktop to laptop or palmtop., • They have very high speed of processing; they are, 100% accurate, reliable, diligent and versatile., , • They have very large storage capacity., Fifth Generation (PRESENT AND FUTURE): 5th, generation computers use ULSI (Ultra-Large Scale, Integration) chips. Millions of transistors are placed in a, single IC in ULSI chips., 64 bit microprocessors have been developed during this, period.. Memory chips and flash memory up to 1 GB,, hard disks up to 600 GB & optical disks up to 50 GB have, been developed (fig. 3)., , CP110113, , CP110113, , Fifth generation computing devices, based on Artificial, Intelligence, are still in development, though there are some, applications, such as voice recognition, that are being used, today., Artificial Intelligence is the branch of computer science, concerned with making computers behave like humans., The term was coined in 1956 by John McCarthy at the, Massachusetts Institute of Technology. Artificial, intelligence includes:, , • Games Playing: Programming computers to play, games such as chess and checkers, , • Expert Systems: Programming computers to make, decisions in real-life situations (for example, some, expert systems help doctors diagnose diseases based, on symptoms), , • Natural Language: Programming computers to, understand natural human languages, , • Neural Networks: Systems that simulate intelligence, , by attempting to reproduce the types of physical, connections that occur in animal brains, , • Robotics: programming computers to see and hear, and react to other sensory stimuli, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 9
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Table - 1, GENERATION, , ELECTRONIC COMPONENT, , ADVANTAGES, , First, , Vaccum tube, , Helped in calculation, and computational work, , Second, , Transistor, , 1.Smaller size, 2.Less cost, 3.Better speed, 4.Low power consumption, and less heat generation, 5.Better storage capacity, 6.Better accuracy and, more reliability, , Third, , Integrated Circuits(IC), small & medium scale, , 1.Better in all aspects, 1.Initial problem withmanufaccompared to I & II, turers, 2.Used operating systems 2.No insight obtained into, and high level language, internal working, , Fourth, , VLSI or Microprocessor, , 1.Low cost, 2.Excellent speed and, reliability, 3.Computers close to man, , Fifth, (Knowledge, Information, Processing, Systems), , ULSI or Bio-Chips, , 1.Very cheap, , 1.Big size, 2.Very costly, 3.Slow speed, 4.Low accuracy, 5.Low storage, 6.High power requirements, 7.High heat generation, 8.High failure rate, 9.Used machine language, 10.No operating system, 1.Need air conditioning, 2.Constant maintenance, 3.No operating systems, 4.Later stage computers used, assembly languages, , 1.Less powerful than main, frame computers, , 1.New low level language, needed, , 2.super speeds, 3.Very high storage capacity, 4.Highly sophisticated OS, 5.posses intelligence and, decision making ability, , Classification of computers, Computers are classified according to the following criteria:, , • Principle of Operation, • Computing Power, Memory Capacity and cost, • Technological Development, • Principle of operation, , It is a computer that measures continuously changing, physical quantities such as current, temperature,, pressure etc. and converts them into quantities which, can be used as data for computation. As these computers, deal with continuously varying quantities they will give, only approximate results. Its output is usually displayed, on a meter or scale. Analog computer has low memory, and fewer functions. These are used for engineering and, scientific applications., , •, , Analog computer, , • Thermometer, , •, , Digital Computer, , • Speedometer, , •, , Hybrid Computer, , • Analog clock, , Analog Computer, 10, , DISADVANTAGES, , Digital Computer, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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A digital computer works with digital data. Digital computer, uses binary number system. Binary number system, consists of only two digits '0' and '1'. A digital computer, represents data in digital signals. A '0' represents OFF, and a '1' represents ON. Digital computer performs, arithmetic and logical operations on data. It gives output, in digital form., , store results. They have large Memory (that is data storing, capacity). Today most of the computers used in offices, and homes are Digital computers., , • Special purpose computers, , Digital computers are very fast. These computers can, , • General purpose computers, , The digital computers are further divided into the, following two groups:, , Table 2, Analog Computers, , Digital Computers, , 1. Analog Computers Work on continuous values., 2 Analog Computers have low memory., 3 Analog computers have Slow speed., , Digital computers Work on discrete values., Digital computers have a very large memory, Digital computers have fast speed., , 4 Analog computers are less reliable., , Digital computers are more reliable., , 5 Analog computers used in engineering, , Digital computers are used in all fields of life., science and medical fields., , 6 Analog computers are used to calculate /, , Digital computers are used to calculate, , measure analog quantities like speed and, , mathematical and logical operations. It can, , temperature., , solve addition, subtraction, division,, multiplication and other mathematical and, statistical operations., , 7 Analog computers provide less accurate results., , Digital computers provide 100% accurate results., , 8 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 9 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 10 Examples of Analog computers are: thermometer,, , Examples of digital computers are:, , analog clock, speedometer etc., , Personal Computer, laptops, smart phones etc., , Special Purpose Computers, It is a computer designed to solve specific type of, problem. The computers used in ships and aircrafts, etc., General Purpose computers, It is a computer designed to solve a wide variety of, problems, A General purpose Computer can store, different programs and process them., The differences between analog and digital computers, are listed in table 2, Hybrid Computer (Fig. 4), A hybrid computer is a combination of both analog and, digital computer. Hybrid computer can handle both, analog and digital data. A hybrid computer combines the, best characteristics of both the analog and digital, computer. It can accept data in both analog and digital, form., Applications, Hybrid computer devices are used in hospitals that may, calculate patient's heart function, temperature and blood, pressure etc. This calculation may be converted into, , numbers and shown in digital form. For example, The Vital, Signs Monitoring unit also called (VSM) in short. It has, Blood Pressure monitor, ECG monitor, respiratory monitor,, and is also used for monitoring anesthesia., , • Hybrid computers are also used in spaceships and, missile system., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 11
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•, , Hybrid Computer Machines are generally used in, scientific applications, , •, , Hybrid computers are used for controlling industrial, processes., , Computers are classified on the basis of computing, power, memory capacity and cost., - Microcomputer or Personal Computer., - Mini Computer., - Mainframe Computer., - Super Computer., Micro Computers, Micro computer is also called personal computer. It was, introduced in 1970. Examples of personal computers are, PC and Apple Macintosh. The major types of personal, computers are desktop computer and portable computer., Fig 6, , Desktop Computer, , CP110116B, , These computers can easily fit on a table or desktop,, hence the name. These computers come in two models, or casings. In Desktop model, the system unit is placed, on the desktop or table. Monitor is placed on the system, unit. In Tower model, both monitor and system unit are, placed on the table as in (Fig 5)., , Palmtops have no keyboard but the screen serves both, as an input and output device. It easily fits in the hand of, the user., Uses of Micro Computer, The PC is the most common type of computer used in, the office. It is now widely used in many homes. These, are also used for business and engineering application., , Portable computer, Portable is a personal computer that can be carried from, one place to other easily. Notebook computer and, handheld computer (smart phone) are examples of, portable computers. Notebook computer is also called, laptop computer. Laptop computers are very small in, size and can be placed easily on lap., , Mini Computer, , Lap top computer or notebook computer, , Minicomputer can serve up to 4000 connected users, simultaneously. It is normally accessed by users via, personal computer or terminal. A device with a monitor, and keyboard is called terminal. It is also known as dumb, terminal. It has no processing power and cannot work as, stand-alone computer. Some of the minicomputers, models are VAX-8800, AS400, , The laptop computer or notebook computer will be as, shown in fig 6a and fig 6b.It is also called as tower model, computer., Palmtop Computer/Digital Diary /Notebook /PDAs:, A handheld computer (like smart phone) is also portable., Hand held computer is known as palmtop computer., 12, , Mini computers were introduced in the 1960s., Minicomputer is larger and more powerful computer than, personal computer. It can execute five million instructions, per second. It generally consists of two or more, processors., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Uses of Mini Computer, Mini computers are often used by small and medium-sized, companies to provide centralized store of information., Mainframe Computer, Mainframe computers were introduced in 1975. A, mainframe computer is a very large computer in size. It is, processors. It is designed to perform multiple tasks for, multiple users at the same time. Mainframe computers, can serve up to 50,000 users at the same time., , programs concurrently. The modern super computer, consists of thousands of microprocessors. Super computer, uses high-speed facilities such as satellite for online, processing., Sum of the super computers models are CRAY-XP, ETA10, Param and Deep Blue ., Advantages of computers, •, , A computer has a very high processing speed with high, reliability., , •, , Large volume of information can be stored in the, memory any particular data/program can be retrieved, immediately., , •, , Solution to a complicated problem is possible at a very, high speed., , •, , Processing of large volume of data saves a lot of clerical, work which reduces the processing cost., , Mainframe computers are used primarily by corporate, and governmental organizations for critical applications,, bulk data processing such as senses, industry and, consumer statistics, and transaction processing., , •, , Computers perform operations efficiently at, environments where presence of human being is not, possible such as furnace, poisonous atmosphere,, vacuum, unmanned satellite, etc., , Super computer, , Limitation of computers, , Super computers were introduced in 1980s. Super, computer is the fastest computer. Super computer is the, biggest in size and the most expensive in price than any, other computers., , •, , High initial cost., , •, , Input information has to be prepared in the form of, statements called program which requires a, considerable amount of knowledge., , •, , usage of computers will be economical only when there, is clerical data processing for large volume of data and, are repetitive in nature, , •, , It is a merely a machine it cannot correct errors on its, own., , The users access a mainframe computer through, terminal or personal computer. A typical mainframe, computer can execute 16 million instructions per second., Some of the main computers models are, •, •, , NEC 610, DEC 10, , Uses of Mainframe Computer, , It is the most sophisticated, complex and advanced, computer. It has a very large storage capacity. It can, process trillions of instructions in one second. Super, Computer is the fastest and most powerful computer of, a time. Supercomputers are very expensive., Supercomputers are used for highly calculation-intensive, tasks. Super computers are also used for specialized, applications that require immense amounts of, mathematical calculations., Applications of Super Computer, •, , Weather forecasting,, , •, , Animated graphics like in Hollywood movies,, , •, , Fluid dynamic calculations, , •, , Nuclear energy research, , •, , Space science, , •, , Weapon and missile design, , •, , Petroleum exploration, and etc., , Today, supercomputers are produced by traditional, companies such as Cray, IBM and Hewlett- Packard., Since October 2010, the Tianhe-1A supercomputer has, been the fastest in the world; it is located inChina., The main difference between a supercomputer and a, mainframe is that a supercomputer channels all its power, into executing a single program as fast as possible,, whereas a mainframe uses its power to execute many, , Functions of Computers, All computers are made up of following basic units as, shown in fig (7). They are as follows:1 Input Unit, 2 Central processing Unit (CPU), a) Arithmetic Logic Unit(ALU), b) Control Unit (CU), 3 Memory, 4 Output Unit, Input Unit, Computers need to receive data and instruction in order, to solve any problem. Therefore we need to input the, data and instructions into the computers. The input unit, consists of one or more input devices. Keyboard is the, one of the most commonly used input device. Some of, the input devices are listed in table 1., Input devices perform the following functions., •, , Accept the data and instructions from the outside world., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 13
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•, , Convert it to a form that the computer can understand., , •, , Supply the converted data to the computer system for, further processing., , Central Processing Unit (CPU) (Fig. 8), The central processing unit (CPU) is the electronic brain, , use in a computer or other digital electronic device., There are two types of memory in computer., •, •, , Primary Memory, Secondary Memory, , Output Unit, Output unit receive the informations from the processing, unit and provide the results in human readeable form., Output Devices, The some of the output devices are, • Monitor, • Printer, • Plotter, • Speaker, Applications of computers, , of the computer as in fig-8. The CPU in a personal computer, is usually a single chip. It organizes and carries out, instructions that come from either the user or from the, software. The processor is made up of many components., CPU performs the following functions:, •, •, •, , It performs all calculations., It takes all decisions., It controls all units of the computer., , Two typical components of a CPU are the following:, The arithmetic logic unit (ALU), which performs arithmetic, and logical operations., The control unit (CU), which extracts instructions from, memory and decodes and executes them, calling on the, ALU when necessary., Memory, Memory refers to the physical device used to store the, program or data on the temporary or permanent basis for, , 14, , Science: Scientists have been using computers to, develop theories and to analyse and test the data. The, high speed and accuracy of the computer allow different, scientific analyses to be carried out. They can be used, to generate detailed studies of how earthquakes affect, buildings or pollution affects weather pattern. Satellitebased applications have not been possible without the, use of computers. Moreover, it would not be possible to, get the information of the solar system and the cosmos, without computers., Education: Computers have also revolutionized the, whole process of education. Currently, the classrooms,, libraries and museums are efficiently utilizing computers, to make the education much more interesting. Unlike, recorded television shows, computer-aided education, (CAE) and computer-based training (CBT) packages are, making learning much more interactive., Medicine and Health Care: There has been an, increasing use of computers in the field of medicine., Now, doctors are using computers right from diagnosing, the illness to monitoring a patient's status during complex, surgery. By using automated imaging techniques, doctors, are able to look inside a person's body and can study, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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CP110117t1, , Fig 9, , each organ in detail (e.g. CT scans or MRI scans), which, was not possible few years ago. There are several, examples of special-purpose computers that can operate, within the human body such as cochlear implant, a, special kind of hearing aid that makes it possible for, deaf people to hear., Engineering/Architecture/Manufacturing: The, architects and engineers are extensively using computers, in designing and drawings. Computers can create objects, , that can be viewed from all the three dimensions. By using, techniques like virtual reality, architects can explore houses, that have been designed but not built. The manufacturing, factories are using computerized robotic arms to perform, hazardous jobs. Besides, computer-aided manufacturing, (CAM) can be used in designing the product, ordering the, parts and planning production. Thus, computers help in, coordinating the entire manufacturing process., , IIT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 15
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Entertainment: Computers are finding greater use in, entertainment industry. They are used to control the, images and sounds. The special effects, which, mesmerize the audience, would not have been possible, without the computers. In addition, computerized, animation and colourful graphics have modernized the, film industry., , Banking: Computers are extensively used in the field of, banking and finance. People can use the ATM (automated, teller machine) services 24 hours a day to deposit and, withdraw cash. When different branches of the bank are, connected through computer networks, the inter branch, transactions such as cheque and draft can be performed, without any delay., , Communication: E-mail or electronic mail is one of the, communication media in which computer is used. Through, e-mail, messages and reports are passed from one person, to one or more persons with the aid of computer and, telephone line. The advantage of this service is that while, transferring the messages it saves time, avoids wastage, of paper and so on. Moreover, the person who is receiving, the messages can read the messages whenever he is, free and can save it, reply it, forward it or delete it from the, computer., , Railway Reservation System, , Business Application: This is one of the important uses, of the computer. Initially, computers were used for batchprocessing jobs, where one does not require the, immediate response from the computer. Currently,, computers are mainly used for real-time applications (like, at the sales counter) that require immediate response, from the computer. There are various concerns where, computers are used such as in business forecasting, to, prepare pay bills and personal records, in banking, operations and data storage, in various types of life, insurance business and as an aid to management., Businesses are also using the networking of computers,, where a number of computers are connected together, to share the data and the information. Use of e-mail and, the Internet has changed the ways of doing business., Publishing: Computers have created a field known as, desktop publishing (DTP). In DTP, with the help of, computer and a laser printer one can perform the, publishing job all by oneself. Many of the tasks requiring, long manual hours such as making table of contents and, index can be automatically performed using the, computers and DTP software., , 16, , Using this system, the user can perform following, operations through online. (web site: www.irctc.co.in), •, •, •, •, , search the train and its timings, check seats and birth availability, booking and cancelling tickets, status of PNR (Passenger Name Record), , Telephone / Electricity Board Billing:, The users can do the following operations through online, by using this system. (Web site: portal.bsnl.in - BSNL), • Register the telephone / electricity board number, • Check and pay the bill amount, • Register the complaints, E-Governance, E-Governance implies technology driven governance., E-Governance is the application of Information and, Communication Technology (ICT) for delivering, government services, exchange of information, communication transactions, integration of various standalone systems and services between Government-toCitizens, (G2C),, Government-toBusiness(G2B),Government-to-Government( G2G) as, well as back office processes and interactions within the, entire government frame work., E-Governance covers all the sectors with a view to, providing hassle free, transparent and efficient service, to the common man (both in urban and rural areas)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise1.2.06, COPA - Introduction to computer components, Introduction to CPU architecture and motherboard, Objectives: At the end of this lesson you shall be able to, • state what is hardware and test the internal and external hardware, • brief the listed hardware, • state what is partitions and their types, • explain the booting and its procedures., Computer Hardware, The physical units of a computer are called as the, hardware of a computer., Internal hardware examples, •, , Blu-Ray, CD-ROM, and DVD, , •, , CPU, , •, , Hard drive, , •, , Motherboard, , •, , RAM, , •, , Sound card, , •, , Video card, , •, , SMPS, , External hardware examples, •, , Flat-panel, Monitor, and LCD, , •, , Keyboard, , •, , Mouse, , •, , Printer, , •, , Scanner, , CPU & ALU, Central Processing Unit (CPU) is the heart of the, Computer. It is the hardware,that carries out the, instructions of a computer program by performing the, basic arithmetical, logical, and input/output operations, of the system., , Most connectors are separated, permitting the cable to, be plugged in only in the correct direction. The keyboard, and mouse use "PS2" (Personal System 2) connectors., The PS2 connectors are color-coded. The purple, connector is for the keyboard. The green connector is, for the mouse., •, , PS/2 Ports: Standard keyboards and mouse often, connect to the computer via the PS/2 ports. To plug, in a keyboard or mouse cable, first match the cable, to the connector. Then push the cable into the, connector. Be sure not to force the connector because, you will end up bending the pins, , •, , Serial & Parallel Ports: The serial port and parallel, port allow connections to printers and other external, devices. To transfer a byte through a serial port, eight, bits are queued and sent bit by bit. However, in a, parallel port, all the eight bits are transferred, simultaneously, , •, , The parallel port, serial port, and video port all use "D", type connectors (DB-25M, DB-9M and DB-15F, respectively). These are called D connectors because, of their shape, which permits the cables to be plugged, in only one way., , CPU Ports and Connectors, A port is a connector at the back of a Computer cabinet, where you plug in an external device such as a printer,, keyboard, scanner, modem etc. This allows instructions, and data to flow between the computer and the device., The computer ports are also commonly referred to as, the Input/output ports (I/O ports). These ports can be, either serial or parallel. Fig 1 shows the commonly, available ports on a personal computer., , Copyright @ NIMI Not to be Republished, , 17
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USB (Universal serial bus) Ports, , The System Unit and Its Components, , Devices like digital cameras, scanners and printers often, connect to the motherboard via the USB ports. A USB, connector's distinctive rectangular shape makes it easily, recognizable., , The system unit is a box-like unit filled with a number of, useful components, each performing a discrete function., These components work together to accomplish the main, function of the computer, viz. accept and process input, and deliver output. This section will elaborate on these, components one by one. Fig 3 shows the various, components of the system unit., , USB has a number of features that makes it particularly, popular on PCs. First, USB devices are hot swappable., You can insert or remove them without restarting your, system, , Fig 3, , LAN(Local Area Network) Port: The LAN port is used, to connect the PC to a local network or to high speed, Internet services., VGA (Video Graphics Array) Ports: The VGA port, provides access to integrated video., Audio ports: It provides access to integrated audio., The audio jacks are the most confusing connectors on, the back panel. Although the jacks are sometimes colorcoded, the devices that plug into them rarely., CPU front Panel shown Fig 2., , CP11011B, , Fig 2, , Power Supply, The power supply connects to nearly every device in the, PC to provide power. It is located at the rear of the case., The system unit draws power from the AC mains through, a power protection device., , It may contain the following parts., , • Power On/Off Switch, • Power Indicator, • CD/DVD Drive, • CD/DVD Drive Open/Close Button, • CD/DVD Drive indicator, • Floppy Disk Drive, • Floppy Disk Drive Indicator, • USB Ports, • Audio and Mic connectors, Design of CPU Cabinets may vary based on, the manufacturer., , 18, , This power is not directly supplied to the internal, components. Instead, one of the components, called the, internal power supply, converts the AC input into DC, output of 5 and 12 volts. Normally, the internal power, supply is referred to as Switched Mode Power Supply, (SMPS)., The SMPS provides cable connectors to supply the, required voltage to the other internal components like, the floppy drives, the hard disk drive, the motherboard, and external device such as the keyboard. The ON/OFF, switch of the system unit is actually a part of the SMPS., Fan, The SMPS has a small fan, called the exhaust fan,, attached to SMPS(Fig. 4). This fan rotates as long as, the computer is switched on. Its function is to cool the, SMPS unit., Drive Bays: The 5.25" and 3.5" drive bays house the, many kinds of storage devices a computer might contain., Expansion Slots: An expansion slot is a slot located, inside a computer mother board that allow additional, peripharals to be connected to it., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Power Port: Power is delivered to drives via cables that, plug into the power port on the drives., , Fig 4, , Peripheral cards slot, The peripheral cards are the spare expansion slots, available on the mother board on which peripheral cards, can be inserted., , CP11011C, , The following are the peripheral cards, , Memory Slot, , •, , Sound card, , •, , Video card, , •, , Modam, , •, , Wireless network, , Fig. 7 shows the peripheral card, designed with a PCI, (Peripheral component interconnect) connector., Fig 7, , Memory Slot is used to insert a Random Access, Memory(RAM) shown in fig 5, , Storage Drivers, Storage drivers such as hard drives, optical drives and, floppy drives all connect to the motherboard via cables, and is mounted inside the computer., IDE & SATA Cables: Fig 6 shows two hard disk drives, that connect in different ways to the motherboard. One, uses the older IDE cable connection while the other uses, SATA(Serial Advanced Technology Attachment) cable, which provides for faster hard drive access., , CP11011F, , CP11011D, , Fig 5, , Motherboard, The motherboard is a printed circuit that is the foundation, of a computer and allows the CPU, RAM, and all other, computer hardware components to function with each, other as on fig 8., Fig 8, , CP11011G, , Fig 6, , CP11011E, , "www. dget.gov.in", , The motherboard is the primary component of the entire, system. A mother board is a large board containing a, number of tiny electronic circuits and other components, are visible. All peripheral devices are connected to the, motherboard. The components of the motherboard are:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 19
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This means you can upgrade to a newer version of DOS, without changing the BIOS. PC BIOS that can handle, Plug-and-Play (PnP)devices are known as PnPBIOS,, These BIOS are always implemented with flash memory, rather than ROM., , •, , Keyboard / mouse port, , •, , Parallel and Serial port, , •, , Processor Socket, , •, , AGP Slot, , CMOS Battery, , •, , PCI Slots, , •, , ISA Slot, , •, , CMOS Battery, , CMOS (Complementary Metal-Oxide-Semiconductor) is, the term usually used to describe the small amount of, memory on a computer motherboard that stores the BIOS, settings., , •, , Data Card Connector, , •, , Memory Slots, , •, , Floppy Port, , •, , Fan Header, , •, , Main Power Connector, , Most CMOS batteries will last the lifetime of a, motherboard (up to 10 years in most cases) but will, sometimes need to be replaced. Incorrect or slow system, date and time and loss of BIOS settings are major signs, of a dead or dying CMOS battery., ISA slot: (Industry Standard Architecture) It is the, standard architecture of the Expansion bus. Motherboard, may contain some slots to connect ISA compatible cards., , Floppy Port :The floppy drive connects to the computer, via a 34-pin ribbon cable, which in turn connects to the, motherboard. A floppy controller is one that is used to, control the floppy drive., RAM slots: Random-Access Memory (RAM) stores, programs and data currently being used by the CPU., RAM is measured in units called bytes. RAM has been, packaged in many different ways, •, , SIMM-Single inline memory module -32 or 72 Pin, , •, , DIMM- Dual Inline Memory module -168 pin., , In most of the PC's uses of the DIMM module, ROM BIOS Chip: This means Read Only Memory Basic, Input-Output System., The built-in software that determines what a computer, can do without accessing programs from a disk. On PCs,, the BIOS contains all the code required to control the, keyboard,, display, screen,, disk, drives,, serialcommunications, and a number of miscellaneous, functions., The BIOS is typically placed in a ROM chip that comes, with the computer (it is often called a ROM BIOS). This, ensures that the BIOS will always be available and will, not be damaged by disk failures., It also makes it possible for a computer to boot itself., Because RAM is faster than ROM, though, many, computer manufacturers design systems so that the, BIOS is copied from ROM to RAM each time the, computer is booted. This is known asshadowing., Many modern PCs have flash BIOS, which means that, the BIOS have been recorded on a flash memory chip,, which can be updated if necessary. The PC BIOS is fairly, standardized, so all PCs are similar at this level (although, there are different BIOS versions). Additional DOS, functions are usually added through software modules., 20, , PCI slot : Intel introduced the Peripheral Component, Interconnect bus protocol. The PCI bus is used to, connect I/O devices to the main logic of the computer., PCI bus has replaced the ISA bus. PC motherboards, have one PCI slot but generally more than one., The PCI bus architecture is a processor-independent bus, specification that allows peripherals to access system, memory directly without using the CPU., AGP slot: The Accelerates Graphics Port (AGP) is a, high-speed point-to-point channel for attaching a video, card to a computer's motherboard., Power supply plug in, The Power supply, as its name implies, provides the, necessary electrical power to make the PC (Personal, Computer) operate. The power supply takes standard, 110-V AC power and converts into +/-12-Volt, +/-5-Volt,, and 3.3-Volt DC power. The power supply connector has, 20-pins, and the connector can go in only one direction., Hard Disk and Partitions, Partitioning is a process of dividing the Hard disk into, several chunks, and uses any one of the portion or, partition to install OS or use two or more partitions to, install multiple OS.., But it can always have one partition, and use up the, entire Hard disk space to install a single OS, but this will, become data management nightmare for users of large, Hard disks., Now, because of the structure of the Master Boot Record, (MBR), has only four partitions, and these four partitions, are called Primary Partitions., Extended Partition is not a usable partition by itself,, but it's like a "container" and it is used to hold, LogicalDrives!That is this Extended Partition can be, subdivided into multiple logical partitions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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In order to boot into a Partition, it must be designated, as bootable partition or Active Partition. Active Partition, is that partition which is flagged as bootable or which, contains OS, this is generally a Primary Partition., , Fig 9, , Types of Partitions:, •, , Master, , •, , Partition, , •, , Extended and, , •, , Logical Extended, , Master Boot Record (MBR): MBR is a small 512 bytes, partition which is at the first physical sector of the hard, disk. The location is denoted as CHS 0,0,1 meaning 0th, Cylinder, 0th Head and 1st Sector., MBR contains a small program known as bootstrap, program which is responsible for booting into any OS., MBR also contains a table known as Partition Table., This Partition Table is a table which lists the available, Primary Partitions in the hard disk. Partition table, considers whole Extended Partition as one Primary, partition and lists it in the table!, So a Partition table can have two possible entries:•, , Up to 4 Primary Partitions., , •, , Up to 3 Primary Partitions and 1 Extended, Partition.(Total not exceeding 4) ., , Partition Boot Sector (PBR): This is the logical first, sector, that is sector at the start of a Primary Partition., This is also 512 byte area, which contains some programs, to initialize or run OS files. All Primary Partitions have, its own PBRs., Extended Boot Sector (EBR): This is the logical first, sector, that is the sector at the start of the Extended, Partition. This EBR contains a Partition Table, which lists, the available Logical Partitions inside Extended Partition., That is it contains the Starting addresses of each Logical, Partitions., Logical Extended Boot Sector (LEBR): This is the, logical first sector residing at the start of each Logical, Partition. This is similar to PBR for Primary Partitions., Booting, Booting is a process of loading the operating system, (OS) and checking all the system software and hardware, those are installed in the computer., Booting procedure of Windows operating system, Functions of BIOS, The first process starts, when the computer switched on, Basic Input Output System (BIOS) perform two functions,, to conduct POST and read MBR (Fig 9)., , POST - POST stands for Power OnSelf Test. POST, checks all the hardware devices connected to a computer, like RAM, hard disk etc and make sure that the system, can run smoothly with those hardware devices. If the, POST is a failure the system halts with a beep sound., Now BIOS checks the boot priority. We can set the, boot priority as CD drive, hard disk or floppy drive., MBR - The next duty of BIOS is to read the MBR. MBR, stands for Master Boot Record and it's the first sector on, a hard disk. MBR contains the partition table and boot, loader., Functions of Boot loader, Now BIOS has passed the control to boot loader and, boot loader is a small program which loads kernel to, computers memory. Actually there are two stages of boot, loaders, stage 1 boot loader and stage 2 boot loader., The stage 1 boot loaderis a link to the stage 2 boot loader., The stage 2 boot loader resides in the boot partition and, it loads the kernel to memory., Boot files and functions, There are three boot files in a Windows operating system, and they are NTLDR, NTDETECT.COM and Boot.ini., The boot files are found in the active partition of hard, disk and its normally C drive in a Windows machine., NTLDR - NTLDR stands for NT Loader and it's the, second stage boot loader. The path of NTLDR is, C:\Windows\i386\NTLDR., Boot.ini - Boot.ini contains the configuration files of, NTLDR. When the operating system is loaded we cannot, pass any arguments to kernel, so those arguments are, passed through boot.ini. You can edit boot.ini by opening, through notepad. The path of Boot.ini is C:\boot.ini., NTDETECT.COM, This file detects hardware's and passes information to, NTLDR. Using the collected information the NTLDR, creates a hardware key and this key is used to detect, hardware's., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 21
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A new hardware key is generated after each reboot of the, operating system and that's why system asks to reboot, after installation of a new hardware. The hardware keys, created by NTLDR can be found in Windows registry at, HKEY_LOCAL_MACHINE ' HARDWARES., Kernel and its functions, After executing the functions of boot files the control is, passed to Kernel. ntoskrnal.exe is the kernel file in a, Windows machine and its path is C:\Windows\system, 32\ntoskrnal.exe., Kernel acts as a layer between software and hardware., The library file hal.dll (C;\Windows\system32\hal.dll) helps, Kernel to interact with hardware's. HAL stands for Hardware, Abstraction Layer and this hal.dll file is machine specific., Now the drivers for hardware's are loaded from the file, C:\Windows\system32\config\system and the Kernel is, loaded to primary memory., Services and log in procedure, When kernel is loaded in the primary memory, services, for each process is started and the registry entry for those, services can be found at HKEY_LOCAL_MACHINE System - Current control set - Services., Winlogon.exe (C:\Windows\system32\winlogon.exe) is, the last service started during this process., Winlogon.exe starts the log in procedures of windows, machine. It first calls the library file msgina.dll, (C:\Windows\system32\msgina.dll)., MSGINA stands for Microsoft Graphics Identification and, Authentication and it provides the log in window. Now, msginal.dll passes the control to LSA (Local Security, Authority), it verifies the username and password from, the SAM file. SAM (Security Accounts Manager) contains, the information about all users created in a Windows, operating system., Now the booting procedure is over and it has reached, the desktop of Windows operating system., Voltage: Every electric charge is capable of doing work, by moving another charge either by attraction or by, repulsion. This ability of a charge to do work represents, its potential. Voltage is generated by the separation of, charges. Voltage or electric potential is the state of, separated charges striving to neutralize each other. The, unit of electric potential is volt. Potential difference is, necessary to cause flow of electric current., Methods of voltage generation: Voltage can be generated, by several ways. Some methods of generating coltage, are:, , • Voltage from chemical reactions, Measuring voltage: Voltage exists between any two, points with different levels of charge. Voltage between, any two points can be measured using an instrument, called VOLTMETER. Meters used to measure current is, called Ammeter. There are meters which can be used to, measure voltage and current and a few other electrical, parameters like resistance. Such meters are called, MULTIMETERS., Types of voltage: As discussed in above paragraphs there, are several sources by which voltage can be developed., Depending upon the voltage source, the voltage developed, can be,, Direct voltage: It is of constant magnitude. It remains at, the same amplitude from the moment it is switched ON, till the moment it is switched - OFF., Alternating voltage: In this type, voltage source changes, its polarity regularly and therefore the direction of, developed voltage., A mixed voltage is a combination of direct voltage and, alternating voltage. The level of voltage is not constant., It varies around a mean value., Electric Current: Electric current is produced when, electric charges move in a definite direction. This, movement is not only of negative charges but also of, positive charges. The strength of electric current is the, quantity of charge which flows across a given cross, section of a conductor every second. The unit of current, strength is Ampere., Current strength = Quantity of charge/time, Measuring current: Electric current is the flow of charge,, in a conductor. So, to measure current must pass through, the measuring device. The current measuring instrument, is called the ammeter of the current meter. There are, different types of ammeters used for measuring different, quantities of current., Types of current: Voltage causes electrical current to, flow. If the cause of current flow is a direct voltage source,, then the current caused by its called direct current (d.c)., On the otherhand, then the current caused is referred as, the alternating current. If a mixed voltage AC and DC) is, applied to an electrical circuit, a mixed current (AC and, DC) will flow through the circuit., Types of power supply: Irrespective of how the, electricity is generated, electricity can be classified into, two types., •, , Alternating current, generally known as AC supply., Direct current, generally known as DC supply., , •, , Voltage from friction, , •, , •, , Voltage from moving magnets or coils, , •, , Voltage from pressure or tension in crystals, , •, , Voltage from heat, , AC supply: The term alternating current supply is given to, a supply source that makes current to flow through a circuit, which reverses or alternates its direction periodically., , •, , Voltage from light, , 22, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Advantages of AC supply, •, , Reduced transmission loss over long distances., , •, , Voltage levels can be changed using simple devices, called transformers., , •, , Reduced severity of electrical shock., , •, , Generating equipments are simple and cheaper, , •, , Can be easily converted to DC supply., , DC supply: The term direct current supply is given to a, supply source that makes current to flow through a circuit, in one direction only. Example of DC supply is batteries., Some types of generators are also designed to give d.c., supply. Such generators are called DC generators., Low tension (LT) voltage: The domestic voltage of 240, volts AC (generated and supplied by hydro or Thermal, or Nuclear generating stations) is called the low tension, (LT) voltage. LT lines enters residential buildings from, electricity poles called as service connection. This 240, volts is used to light up the lamps, run fans etc in homes., To connect electrical appliances at home, 240V AC is, available in either two-pin or three - pin sockets. This LT, voltage of 240 volts, 50Hz is also used to supply electrical, and electronic gadgets such as Iron box, washing, machine, personal computer etc., Phase, Neutral and Earth points of LT supply: The, domestic AC mains supply of 240V, 50Hz, is available, at consumers residence either in a 2-pin outlet (Phase Neutral) or in a 3-pin outlet (phase -Neutral and Ground)., These are commercially referred to as 2/3 pin sockets., These sockets look similar to the ones shown in Fig. 10., , recorders etc., Hence such gadgets does not need earth, pin/point on the socket., Iron box, washing machines, drill guns, Desk top computer, invariably need sockets with provision of earth pin, because, of the possibility of shock while using these equipments., Hence such equipments/gadgets make use of AC mains, socket with earth., Connection of 3-pin AC mains socket: Fig 11 shows, how the main supply is connected to the socket., Fig11, , Note that in a AC outlet be it a 2-pin or a 3-pin phase is, always connected to the socket through a switch. This, prevents the users from getting electrical shock when the, switch is put in off position., The standard voltage appearing across the 3-pin terminals, is shown in Fig12, Fig 12, , Fig 10, , Phase: The line or phase point in a socket, can be termed, as the point from where the electricity starts flowing into a, closed circuit., Neutral: The neutral point in the socket, can be termed, as the point which receives electricity from the closed, circuit., Earth / Ground: The ground (some call it Earth) point in, an electrical socket provides the easiest path for the, leakage current and other minor electrical defect currents, of appliances., Two pin mains sockets are used to supply main to such, equipments or apparatus or gadgets generally having its, cabinets/chassis made of plastic such as radio, tape, , The voltages across the pins of the socket can be measured, using an AC voltmeter or a multimeter in AC volts range., As a quick test to find out whether or not a socket is, delivering the AC supply as required, a simple instrument, called line tester which looks similar to a small screw, driver can be used. This instrument will have a small, bulb in it which glows if it is touched to the phase pin in, the socket. Ask your instructor to demonstrate the use of, such line tester to check a AC mains socket., Most Desk top computers need AC mains supply for its, operation. Although the mains supply available in the 3pin socket shown above can be used, mostly this AC, supply is cleaned fro spikes before connecting to, computers. The device used for cleaning the spikes in the, mains AC supply are called Spike Arrestors or Spike, busters., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 23
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Computers are used with spike busters because, AC spikes, are likely to damage the costly computers. In addition to, spike busters, most computers use other power safety, devices called the voltage stabilizers and uninterrupted, power supplies., , 24, , Power supply in computers: Power supply unit in, computers are firmly fitted on the processing unit cabinet, using torx screws. Generally there will be four such screws, fitted to fix the power supply init in the cabinet., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise : 1.3.07 - 1.3.11, COPA - Windows Operating System, Windows Operating System, Objective: At the end of this exercise you shall be able to, • list out the windows versions and features, Windows versions and its features, Microsoft Windows has seen nine major versions since, its first release in 1985. Over 29 years later, Windows, looks very different but somehow familiar with elements, that have survived the test of time, increases in, computing power and - most recently - a shift from the, keyboard and mouse to the touchscreen., Here's a brief look at the history of Windows, from its, birth at the hands of Bill Gates with Windows 1 to the, latest arrival under new Microsoft chief executive, SatyaNadella., , Apple's Macintosh and the Commodore Amiga graphical, user interfaces, coming pre-installed on computers from, PC-compatible manufacturers including Zenith Data, Systems., Windows 3 introduced the ability to run MS-DOS, programmes in windows, which brought multitasking to, legacy programmes, and supported 256 colours bringing, a more modern, colourful look to the interface., More important - at least to the sum total of human time, wasted - it introduced the card-moving timesink (and, mouse use trainer) Solitaire., , Windows 1, , Windows 3.1, , The first version of Windows, , Windows 3.1 with Minesweeper., , This is where it all started for Windows. The original, Windows 1 was released in November 1985 and was, Microsoft's first true attempt at a graphical user interface, in 16-bit., , Windows 1 and 2 both had point release updates, but, Windows 3.1 released in 1992 is notable because it, introduced TrueType fonts making Windows a viable, publishing platform for the first time., , Development was spearheaded by Microsoft founder Bill, Gates and ran on top of MS-DOS, which relied on, command-line input., , Minesweeper also made its first appearance. Windows, 3.1 required 1MB of RAM to run and allowed supported, MS-DOS programs to be controlled with a mouse for, the first time. Windows 3.1 was also the first Windows, to be distributed on a CD-ROM, although once installed, on a hard drive it only took up 10 to 15MB (a CD can, typically store up to 700MB)., , It was notable because it relied heavily on use of a mouse, before the mouse was a common computer input device., To help users become familiar with this odd input system,, Microsoft included a game, Reversi (visible in the, screenshot) that relied on mouse control, not the, keyboard, to get people used to moving the mouse, around and clicking onscreen elements., Windows 2, Windows 2 with overlapping windows., Two years after the release of Windows 1, Microsoft's, Windows 2 replaced it in December 1987. The big, innovation for Windows 2 was that windows could overlap, each other, and it also introduced the ability to minimise, or maximise windows instead of "iconising" or "zooming"., The control panel, where various system settings and, configuration options were collected together in one, place, was introduced in Windows 2 and survives to this, day., Microsoft Word and Excel also made their first, appearances running on Windows 2., Windows 3, Windows 3.0 got colourful., The first Windows that required a hard drive launched in, 1990. Windows 3 was the first version to see more, widespread success and be considered a challenger to, , Windows 95, Windows 95: oh hello Start menu., As the name implies, Windows 95 arrived in August 1995, and with it brought the first ever Start button and Start., It also introduced the concept of "plug and play" - connect, a peripheral and the operating system finds the, appropriate drivers for it and makes it work. That was, the idea; it didn't always work in practice., Windows 95 also introduced a 32-bit environment, the, task bar and focused on multitasking. MS-DOS still, played an important role for Windows 95, which required, it to run some programmes and elements., Internet Explorer also made its debut on Windows 95, but, was not installed by default requiring the Windows 95 Plus!, pack. Later revisions of Windows 95 included IE by default,, as Netscape Navigator and NCSA Mosaic were popular at, the time., Windows 98, Windows 98, the last great DOS-based Windows., Released in June 1998, Windows 98 built on Windows, 95 and brought with it IE 4, Outlook Express, Windows, , Copyright @ NIMI Not to be Republished, , 25
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Address Book, Microsoft Chat and NetShow Player, which, was replaced by Windows Media Player 6.2 in Windows, 98 Second Edition in 1999., , CD burning, autoplay from CDs and other media, plus, various automated update and recovery tools, that unlike, Windows ME actually worked., , Windows 98 introduced the back and forward navigation, buttons and the address bar in Windows Explorer, among, other things. One of the biggest changes was the, introduction of the Windows Driver Model for computer, components and accessories - one driver to support all, future versions of Windows., , Windows XP was the longest running Microsoft operating, system, seeing three major updates and support up until, April 2014 - 13 years from its original release date., Windows XP was still used on an estimated 430m PCs, when it was discontinued., , USB support was much improved in Windows 98 and, led to its widespread adoption, including USB hubs and, USB mice., Windows ME, Windows ME was one to skip., Considered a low point in the Windows series by many at least, until they saw Windows Vista - Windows, Millennium Edition was the last Windows to be based on, MS-DOS, and the last in the Windows 9x line., Released in September 2000, it was the consumer-aimed, operating system twined with Windows 2000 aimed at, the enterprise market. It introduced some important, concepts to consumers, including more automated, system recovery tools., IE 5.5, Windows Media Player 7 and Windows Movie, Maker all made their appearance for the first time., Autocomplete also appeared in Windows Explorer, but, the operating system was notorious for being buggy,, failing to install properly and being generally poor., Windows 2000, Windows 2000 was ME's enterprise twin., The enterprise twin of ME, Windows 2000 was released, in February 2000 and was based on Microsoft's businessorientated system Windows NT and later became the, basis for Windows XP., Microsoft's automatic updating played an important role, in Windows 2000 and became the first Windows to, support hibernation., Windows XP, Windows XP still survives to this day., Arguably one of the best Windows versions, Windows, XP was released in October 2001 and brought Microsoft's, enterprise line and consumer line of operating systems, under one roof., Advertisement, It was based on Windows NT like Windows 2000, but, brought the consumer-friendly elements from Windows, ME. The Start menu and task bar got a visual overhaul,, bringing the familiar green Start button, blue task bar, and vista wallpaper, along with various shadow and other, visual effects., ClearType, which was designed to make text easier to, read on LCD screens, was introduced, as were built-in, 26, , Its biggest problem was security: though it had a firewall, built in, it was turned off by default. Windows XP's huge, popularity turned out to be a boon for hackers and, criminals, who exploited its flaws, especially in Internet, Explorer, mercilessly - leading Bill Gates to initiate a, "Trustworthy Computing" initiative and the subsequent, issuance of to Service Pack updates that hardened XP, against attack substantially., Windows Vista, Windows Vista, arguably worse than Windows ME., Windows XP stayed the course for close to six years, before being replaced by Windows Vista in January 2007., Vista updated the look and feel of Windows with more, focus on transparent elements, search and security. Its, development, under the codename "Longhorn", was, troubled, with ambitious elements abandoned in order, to get it into production., Advertisement, It was buggy, burdened the user with hundreds of requests, for app permissions under "User Account Control" - the, outcome of the Trustworthy Computing initiative which, now meant that users had to approve or disapprove, attempts by programs to make various changes., The problem with UAC was that it led to complacency,, with people clicking "yes" to almost anything - taking, security back to the pre-UAC state. It also ran slowly on, older computers despite them being deemed as "Vista, Ready" - a labelling that saw it sued because not all, versions of Vista could run on PCs with that label., PC gamers saw a boost from Vista's inclusion of, Microsoft's DirectX 10 technology., Windows Media Player 11 and IE 7 debuted, along with, Windows Defender an anti-spyware programme. Vista, also included speech recognition, Windows DVD Maker, and Photo Gallery, as well as being the first Windows to, be distributed on DVD. Later a version of Windows Vista, without Windows Media Player was created in response, to anti-trust investigations., Windows 7, Windows 7 was everything Windows Vista should, have been., Considered by many as what Windows Vista should have, been, Windows 7 was first released in October 2009. It, was intended to fix all the problems and criticism faced, by Vista, with slight tweaks to its appearance and a, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished
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concentration on user-friendly features and less "dialogue, box overload"., It was faster, more stable and easier to use, becoming, the operating system most users and business would, upgrade to from Windows XP, forgoing Vista entirely., Handwriting recognition debuted in 7, as did the ability, to "snap" windows to the tops or sides of the screen,, allowing faster more automatic window resizing., , Windows 8.1, Windows 8.1 and the great reappearance of the Start, button., A free point release to Windows 8 introduced in October, 2013, Windows 8.1 marked a shift towards yearly, software updates from Microsoft and included the first, step in Microsoft's U-turn around its new visual interface., , Windows 7 saw Microsoft hit in Europe with antitrust, investigations over the pre-installing of IE, which led to, a browser ballot screen being shown to new users, allowing them to choose, which browser to install on first, boot., , Windows 8.1 re-introduced the Start button, which, brought up the Start screen from the desktop view of, Windows 8.1. Users could also choose to boot directly, into the desktop of Windows 8.1, which was more suitable, for those using a desktop computer with a mouse and, keyboard than the touch-focused Start screen., , Windows 8, , Windows 10, , Windows 8 focused more on touch than a keyboard, and mouse., , With Windows 10, Microsoft is trying to keep some of, the touch and tablet features it created for Windows 8,, combine them with the familiar Start menu and desktop,, and run it all on top of an improved operating system, with more security, a new browser, the Cortana assistant,, its own version of Office for on-the-go editing and plenty, of new features intended to make life simpler., , Released in October 2012, Windows 8 was Microsoft's, most radical overhaul of the Windows interface, ditching, the Start button and Start menu in favour of a more touchfriendly Start screen., Advertisement, The new tiled interface saw programme icons and live, tiles, which displayed at-a-glance information normally, associated with "widgets", replace the lists of, programmes and icons. A desktop was still included,, which resembled Windows 7., , Of course, that also means it's very different to use,, whether you come from Windows 7, Windows 8 or, Windows XP. You have to look in a new place even to, turn your PC off., , Windows 8 was faster than previous versions of Windows, and included support for the new, much faster USB 3.0, devices., , On top of that, Windows 10 is more than just a PC, operating system; it's also what will run on Windows, phones - and on small tablets as well, because a 6-inch, phone and a 7-inch tablet aren't such very different, devices., , The Windows Store, which offers universal Windows, apps that run in a full-screen mode only, was introduced., Programs could still be installed from third-parties like, other iterations of Windows, but they could only access, the traditional desktop interface of Windows., , Microsoft is expecting people to put Windows 10 on a, billion devices (which ought to encourage more app, developers to at least take a look at building their apps, for Windows phones and tablets, as well as for Xbox, One and HoloLens)., , The radical overhaul was not welcomed by many., Microsoft attempted to tread a fine line between, touchscreen support and desktop users, but ultimately, desktop users wanting to control Windows with a, traditional mouse and keyboard and not a touchscreen, felt Windows 8 was a step back., , The Start menu evolves, , There were also too few touchscreens in use, or on offer,, to make its touch-oriented interface useful or even, necessary - despite the parallel rise of tablets such as, the iPad, and smartphones, which had begun outselling, PCs by the end of 2010., , The full-screen Start screen of Windows 8 is back to, being a Start menu in Windows 10 that tries to combine, the best of both options. A scrolling Start menu that's, restricted to a single column, with jump lists and flyout, menus for extra options, divided into frequently used, and recently installed programs, with the option to switch, to a scrolling view of all the applications, sorted, alphabetically., Fig 1, , It looked and felt like Windows 8, but could not run, traditional Windows applications, instead solely relying, on the Windows Store for third-party apps., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13701, , Windows RT, which runs on ARM-based processors, traditionally found in smartphones and non-PC tablets,, was introduced at the same time as Windows 8 with the, Microsoft Surface tablet., , 27
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But also get an extra pane ,where can pin Windows 8style tiles, complete with 'rotating 3D cube' animations of, live tiles. drag the Start menu to be a larger size or even, set it to be full screen., Desktop Background, Another component of the Desktop is the Background., This is simply an image that appears at the back of the, screen. Most computers come with a pre-selected, background, but change it to any image., , alternative is to use the File Explorer by clicking on the, Folder icon on the Taskbar., In the File Explorer window, browse all the folders and, documents., Fig 4, , To change the background, follow these steps:, 1. Right-click on the background and choose, "Personalize", 2. From the Personalization window, choose from a series, of pre-selected pictures or browse for your own., After choosing a picture, the Background will change, automatically., Copa 13704, , Start Menu, If looking for a specific application, open the Start Menu, and click "All Applications". This will open an alphabetical, , Fig 2, , Virtual Desktops, One of the new features of Windows 10 is the addition of, Virtual Desktops. This allows you to have multiple desktop, screens where to keep open windows organized., , Copa 13705, , Copa 13702, , Fig 5, , list of all the applications installed on computer., , To add a virtual desktop, follow these steps:, , Fig 3, , File Explorer, If you are looking for a specific document, another, , 28, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13706, , Copa 13703, , Fig 6
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1. Click Task View on the Taskbar, 2. Click the "New desktop" option on the lower-right corner., You can access or delete the new Desktop by clicking, Task View again., Cortana helps as with search and control, Cortana, the Windows Phone assistant, shows up in, , Fig 7, , If Cortana isn't active, can turn it on by typing "Cortana" in, the Taskbar search to access the Cortana settings, or, just clicking the "Gear" icon on the left-side of the menu., After activating Cortana, it will start gathering information, about to personalize the experience., Task switcher, Most Windows users don't know the Alt-Tab keyboard, , Copa 13707, , Fig 10, , Windows 10 as a search pane on the taskbar, which can, also trigger by saying 'Hey Cortana' - and when start, searching the Start menu., Fig 8, , combination to see and switch between all running apps,, so as well as having a redesigned task switcher with bigger, , Copa 13708, , Fig 11, , That gets theapps have installed, documents access to,, apps could install from the Store, search results from the, web and a range of other information - including from apps, and services that integrate with Cortana., Activating Cortana, , Copa 137011, , Fig 9, , thumbnails, Windows 10 also puts a task view icon in the, taskbar to help them find it., Copa 13709, , TASKBAR, The Windows 10 taskbar sits at the bottom of the screen, giving the user access to the Start Menu, as well as the, icons of frequently used applications. On the right-side,, the Taskbar features the Notification Area which informs, the user of different things like the state of the Internet, connection or the charge of the laptop battery., The icons in the middle of the Taskbar are "pinned", applications, which is a way to have a quick access to, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , 29
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applications you use frequently. "Pinned" applications, will stay in the Taskbar until you "unpin" them., , Copa 1137012, , Fig 12, , Taskbar. It shows different types of notifications from your, computer like your Internet connection, or the volume level., At first, the Notification Area shows a limited amount of, icons. But you can click the upward arrow on its left-side, to see other icons as well., Snap Assist, Because all the apps and programs run in windows on the, Fig 15, , Pin an Application to the Taskbar, Copa 137015, , Step 1: Search for the application you want to pin in the, Start Menu., Step 2: Right-click on the application., Step 3: Select "More" option at the top of the menu., Step 4: Select the "Pin to taskbar" option., Unpin an Application from the Taskbar, To "unpin" it, just right-click the icon in the Taskbar and, select "Unpin from taskbar". You can "pin" it back again, , desktop, instead of modern apps from the Store being in, their own space, and can no longer drag across the left, edge of the screen to bring another app on screen and get, a split view. Instead, drag windows into the corners of the, screen to get the familiar Snap view., Now use all four corners of the screen if want each window, to take up a quarter of the screen instead of half, and the, space that isn't filled by the window you just dragged shows, thumbnails of your other windows to make it easier to, snap the next one into place., , Fig 13, , Action Center, , Copa 137013, , If we used Windows Phone 8.1 (or Android and/or iOS),, we used to a notification centre can drag down from the, top of the screen., , any time you want., Notification Area, The Notification Area is located at the right side of the, , Fig 14, , The command prompt, Those of us that use the command prompt have been, stuck with pretty much the same experience since the, 1990s, but in Windows 10 can finally resize the, command prompt window and use familiar keyboard, shortcuts to copy and paste at the command prompt., It's far from ground-breaking but it's a very welcome, improvement after years of frustration., FILE EXPLORER, , Copa 137014, , 30, , Windows 10 puts that on the right of the screen, where, the charms bar was in Windows 8, with notifications from, various apps at the top and the choice of various settings, buttons at the bottom for quick access., , File Explorer is the file management application used, by Windows operating systems to browse folders and, files. It provides a graphical interface for the user to, navigate and access the files stored in the computer., The main way to access the File Explorer is by clicking, the folder icon in the Taskbar. After clicking the icon, the, File Explorer window will open., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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Multiple desktops, , Fig 15, , User need to arrange a lot of windows and don't have, multiple monitors, user can put them on multiple virtual, desktops. And can use Alt-Tab to move between apps, as usual and then Windows-Ctrl and the left and right, arrow keys to move between desktops., , Copa 137015, , Schedule restarts, , The initial File Explorer window is comprised of the following, sections:, 1. The File Explorer ribbon, which resembles the ribbon, featured in Microsoft Office. The ribbon contains buttons, for common tasks to perform with your files and folders., 2. The Navigation Pane gives you access to your, libraries of documents and pictures, as well as your, storage devices. It also features frequently used folders, and network devices., 3. The Frequent folders section on the right features, the folders you've worked with recently to allow for quick, access to them., 4. The Recent files section in the lower part of the, window features files and documents that you've opened, recently., The new Edge browser, To catch up with fast-moving browsers like Chrome and, Firefox, Microsoft took its browser back to basics, ripping, out years of code that didn't fit with web standards and, making a lean, fast browser., It's a work in progress - it won't get support for things like, ad-blocking extensions until a while after Windows 10, launches - but can do plenty of neat things here. For, example, and can scribble notes on a web page to send, to a friend and Edge has Cortana built in to pull useful, information out of web pages, like the phone number of, a restaurant, or the opening hours., Sites like Medium that didn't work properly with IE should, look better and have more features in Edge., , No more having Windows announce that you have fifteen, minutes to get everything done before it restarts to apply, an update. Instead of leaving Windows 10 to decide when, to do that, if there's an update that will need a restart, and can have Windows ask when you want to schedule, that for., user can only do that once the update has been, downloaded. If user want to have certain times off-limits, for restarts, they will need the features in Windows, Update for Business (for Windows 10 Pro and Enterprise), which lets block restarts so they don't happen in working, hours, or on certain dates., Universal apps - including Office, Windows 10 gets a new Windows Store, where download, desktop programs as well as modern Windows apps., Many of those apps will be universal apps that are the, same code on a PC, a Windows phone, an Xbox One, and even on HoloLens, with the interface changing to, suit the different screen sizes. The Office for Windows, apps like Word and Excel are universal apps, as are the, Outlook Mail and Calendar apps., Settings and control panel, The Windows 8 Settings app has taken over many more, of the settings that used to be in Control Panel, and it, has a Control Panel-style interface with icons to navigate, with. But the old Control Panel interface is still there, for, settings that aren't in the new Settings app (or if you're, just used to finding things there)., Windows 10 - Keyboard ShortcutsUTS, Like most Windows applications, there are several, keyboard shortcuts you can use to make it easier or faster, for some to perform certain tasks., Most of the new Windows shortcuts use the Windows, key () combined with other keys to perform several, actions. The following are some of the most common or, useful shortcuts used in Windows 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished, , 31
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Keyboard Shortcuts for Navigating Windows 10, Press This, , 32, , To Do This, , Windows Logo, , Toggle the Start menu, , Windows Logo+A, , Open the Notifications pane, , Windows Logo+B, , Activate the notification area's Show Hidden Icons arrow (press Enter to display, the hidden icons), , Windows Logo+C, , Open Cortana for voice commands, , Windows Logo+D, , Minimize all open windows to display the desktop, , Windows Logo+E, , Run File Explorer, , Windows Logo+F, , Display the Start menu and activate the Search box, , Windows Logo+H, , Display the Share pane, , Windows Logo+I, , Run the Settings app, , Windows Logo+K, , Display the Devices pane, , Windows Logo+L, , Lock your computer, , Windows Logo+M, , Minimize all windows, , Windows Logo+O, , Turn the tablet orientation lock on and off, , Windows Logo+P, , Display the Project pane to configure a second display, , Windows Logo+Q, , Open Cortana for voice commands, , Windows Logo+R, , Open the Run dialog box, , Windows Logo+S, , Open Cortana for keyboard commands, , Windows Logo+T, , Activate the taskbar icons (use the arrow keys to navigate the icons), , Windows Logo+U, , Open the Ease of Access Center, , Windows Logo+W, , Activate the Search box, , Windows Logo+X, , Display a menu of Windows tools and utilities, , Windows Logo+Z, , Display an app's commands (although this works in only some Modern apps), , Windows Logo+=, , Open Magnifier and zoom in, , Windows Logo+-, , Zoom out (if already zoomed in using Magnifier), , Windows Logo+,, , Temporarily display the desktop, , Windows Logo+Enter, , Open Narrator, , Windows Logo+Left, , Snap the current app to the left side of the screen, , Windows Logo+Right, , Snap the current app to the right side of the screen, , Windows Logo+Up, , Restore a minimized app; maximize a restored app, , Windows Logo+Down, , Restore a maximized app; minimize a restored app, , Windows Logo+PgUp, , Move the current app to the left monitor, , Windows Logo+PgDn, , Move the current app to the right monitor, , Windows Logo+PrtSc, , Capture the current screen and save it to the Pictures folder, , Windows Logo+Ctrl+D, , Create a virtual desktop, , Windows Logo+Ctrl+Right, , Switch to the next virtual desktop, , Windows Logo+Ctrl+Left, , Switch to the previous virtual desktop, , Windows Logo+Ctrl+F4, , Close the current virtual desktop, , Windows Logo+Tab, , Open Task View, which displays thumbnails for each running app as well as, the available virtual desktops, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Windows Opeating System, , Related Theory for Exercise 1.3.12, , Handling printers, Objectives : At the end of this lesson you shall be able to, • explain about typewriter, • explain about printer, • explain types and cost of printers, • explain programming languages for printers, • explain how to locate printer driver files., Typewriter, A typewriter is a mechanical or electromechanical device, with keys that, when pressed, cause characters to be, printed on a medium, usually paper as on Fig 1. Typically, one character is printed per keypress, and the machine, prints the characters by making ink impressions of type, elements similar to the sorts used in movable type, letterpress printing., , Fig 2, , Fig 1, , Fig 3, , After their invention in the 1860s, typewriters quickly, became indispensable tools for practically all writing other, than personal correspondence. They were widely used, by professional writers, in offices, and for business, correspondence in private homes. By the end of the, 1980s, word processors and personal computers had, largely displaced typewriters in most of these uses., Computer printer, A printer is a piece of hardware for a computer as on, Fig 2. It is a device that must be connected to a computer, which allows a user to print items on paper, such as letters, and pictures. It can also work with digital cameras to, print directly without the use of a computer., Types of printers, Today, the following types of printers are in regular use:, Daisy wheel printing is an impact printing technology, invented in 1969 by David S. Lee atDiablo Data Systems, as on Fig 3. It uses interchangeable pre-formed type, elements, each with typically 96 glyphs, to generate highquality output comparable to premium typewriters such, , as theIBM Selectric, but two to three times faster. Daisy, wheel printing was used in electronic typewriters, word, processors and computers from 1972. According to, Webster's, the daisy wheel is so named because of its, resemblance to the daisy flower., , Copyright @ NIMI Not to be Republished, , 33
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Dot-matrix printers are now almost extinct. They used a, ribbon and made a lot of noise. There were models with, 9 pins and models with 24 pins as on Fig 4. A dot matrix, printer or impact matrix printer is a type of computer, printer with a print head that runs back and forth, or in an, up and down motion, on the page and prints by impact,, striking an ink-soaked cloth ribbon against the paper,, much like the print mechanism on a typewriter., , Fig 6, , Fig 4, , such wide-format printers as "plotters," even though they, technically are not., , Inkjet printing is a type of computer printing that creates, a digital image by propelling droplets of ink onto paper, as on Fig 5. Inkjet printers are the most commonly used, type of printer, and range from small inexpensive, consumer models to very large professional machines, that can cost tens of thousands of dollars., , Pen plotters print by moving a pen or other instrument, across the surface of a piece of paper. This means that, plotters are restricted to line art, rather than raster, graphics as with other printers. Pen plotters can draw, complex line art, including text, but do so slowly because, of the mechanical movement of the pens. They are often, incapable of efficiently creating a solid region of color,, but can hatchan area by drawing a number of close,, regular lines., Laser printing is a digital printing process that rapidly, produces high quality text and graphics on plain paper., As with digital photocopiers and multifunction printers, (MFPs), laser printers employ a xerographic printing, process, but differ from analog photocopiers in that the, image is produced by the direct scanning of a laser beam, across the printer's photoreceptor., , Fig 5, , A laser beam projects an image of the page to be printed, onto an electrically charged rotating drum coated with, selenium or, more common in modern printers, organic, photoconductors. Photoconductivity allows charge to leak, away from the areas exposed to light., , The concept of inkjet printing originated in the 20th, century, and the technology was first extensively, developed in the early 1950s. Starting in the late 1970s, inkjet printers that could reproduce digital images, generated by computers were developed, mainly by, Epson,Hewlett-Packard (HP), and Canon. In the, worldwide consumer market, four manufacturers account, for the majority of inkjet printer sales: Canon, HP, Epson,, and Lexmark, a 1991 spin-off from IBM., The plotter is a computer printer for printing vector, graphics as on Fig 6. In the past, plotters were used in, applications such as computer-aided design, though they, have generally been replaced with wide-format, conventional printers. It is now commonplace to refer to, 34, , Dry ink (toner) particles are then electro statically picked, up by the drum's charged areas, which have not been, exposed to light. The drum then prints the image onto, paper by direct contact and heat, which fuses the ink to, the paper., Cost of printers, There are different costs with a printer. Printers that are, more expensive to buy will usually be less expensive in, the consumables (the ink, toner, or ribbon used by the, printer). Therefore, laser printers are often more, expensive to buy than inkjet printers, but are not, expensive to use over a long period of time., Inkjet printers on the other hand have a higher cost of, consumables because the ink tanks they use are more, expensive than the toner for a laser printer., Laser printers that can print in color are usually more, expensive than those that only print in black and white., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished
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Other options, like being able to print on both sides of a, sheet of paper, to automatically sort the output, or to, staple the output will also make a printer more expensive., , Fig 7, , Common programming languages for printers, include:, ESC/P, , •, , Postscript, , •, , PCL, , •, , GDI, , •, , HPGL and HPGL/2, , •, , PDF, , Prominent features of a scanner include:, , •, , VPS, , •, , Reliability - Unlike certain forms of data transmission,, scanning involves only transfer of hard images to, digital forms. The role of the end-user is limited in, case of scanning. And as they are not dependent on, two-way communication, they can also help in storing, important information or transmitting important, information., , •, , Efficiency - Modern scanners are built for efficiency, and speed. And it comes with ease of use as well as, convenience., , •, , Quality - Scanning ensures the best resolution, possible for digital images. Compared to fax, machines, which may find it difficult to reproduce the, accurate details, scanners can reproduce images with, high resolution and precisions. They are quite useful, for photography and engineering arenas., , •, , Cost saving - One of the biggest advantage of, scanning is the replacement of physical files/forms, with digital ones. Along with saving physical space,, which has to be used for storage, there are also, environmental benefits by using scanner., , Copa 110107, , •, , How to Locate Printer Driver Files, Printers can be connected to a computer by a variety of, wired and wireless methods, but all printers require, drivers to be installed on a computer. The printer drivers, are small programs that help communicate information, from the operating system to the printer., Driver errors can make the printer unusable. Using the, Windows device manager, you can look up details about, the drivers as well as pinpoint their physical location on, your hard drive., Scanner, A scanner is an electronic device which can capture, images from physical items and convert them into digital, formats, which in turn can be stored in a computer, and, viewed or modified using software applications., Different types of scanners are available with different, resolutions. In the world of electronic data transmission,, scanning is considered to be the most cost-effective and, reliable way of transmitting images., The basic principle of a scanner is to analyze an image, and reproduce it to a digital one using the optical, character recognition techniques., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished, , 35
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IT & ITES, Related Theory for Exercise 1.4.13, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., The Basic Input/Output System (BIOS), also known as, System BIOS, ROM BIOS or PC BIOS is a generally, accepted standard defining a firmware interface., , •, , The fundamental purpose of the BIOS is to initialize and, test the system hardware components and load an, operating system from a mass memory device. The BIOS, is special software that interfaces the major hardware, components of the computer with the operating system., It is usually stored on a Flash memory chip on the, motherboard, but sometimes the chip is another type of, ROM. The BIOS is a firmware (software instructions, permanently recorded on a chip located on your, motherboard). (Refer Fig.1)., , The first thing the BIOS will do is check the information, stored in a tiny (64 bytes) amount of RAM located on a, complementary metal oxide semiconductor (CMOS), chip. The CMOS Setup provides detailed information, particular to your system and can be altered as your, system changes. The BIOS uses this information to, modify or supplement its default programming as, needed., , Copa 181301, , Fig 1, , Functions of BIOS, The BIOS software has a number of different roles, but, its most important role is to load the operating system., The BIOS checks and initializes the PC hardware each, time the system powers up or restarts before handing, over control to the operating system. Some of the other, common tasks that the BIOS performs include:, •, , A power-on self-test (POST) for all of the different, hardware components in the system to make sure, everything is working properly, , •, , Activating other BIOS chips on different cards installed, in the computer - For example the graphics cards often, have their own BIOS chips., , •, , Providing a set of low-level routines that the operating, system uses to interface to different hardware, devices. They manage things like the keyboard, the, screen, and the ports, especially when the computer, is booting., , 36, , Managing a collection of settings for the hard disks,, clock, etc., , CMOS Setup, , Configuring BIOS, The BIOS checks the CMOS Setup for custom settings., To change the CMOS settings we need to enter the, CMOS setup. To enter the CMOS Setup, a certain key, or combination of keys must be pressed during the initial, startup sequence. Most systems use "Esc," "Del," "F1,", "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. There is, usually a line of text at the bottom of the display that, tells "Press ___ to Enter Setup.", The BIOS setup shows a set of text screens with a, number of options. Some of these are standard, while, others vary according to the BIOS manufacturer., Common options include:, •, , System Time/Date - Set the system time and date, , •, , Boot Sequence - The order that BIOS will try to load, the operating system, , •, , Plug and Play - A standard for auto-detecting connected, devices; should be set to "Yes" if your computer and, operating system both support it, , •, , Mouse/Keyboard - "Enable Num Lock," "Enable the, Keyboard," "Auto-Detect Mouse"..., , •, , Drive Configuration - Configure hard drives, CD-ROM, and floppy drives, , •, , Memory - Direct the BIOS to shadow to a specific, memory address, , •, , Security - Set a password for accessing the computer, , •, , Power Management - Select whether to use power, management, as well as set the amount of time for, "standby" and "suspend", , Copyright @ NIMI Not to be Republished
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•, , Exit - Save your changes, discard your changes or, restore default settings., , The BIOS uses CMOS technology to save any changes, made to the computer's settings. With this technology, a, small lithium or Ni-Cad battery can supply enough power, to keep the data for years. Major BIOS manufacturers, include American Megatrends Inc. (AMI), Phoenix, Technologies, Winbond etc. A typical BIOS screenshot, is shown in fig. given below.(Refer Fig.2), Fig 2, , •, , Use of multi-boot setups, which allow users to have, more than one operating system on a single computer., For example, one could install Linux and Microsoft, Windows or other operating systems on different, partitions of the same HDD and have a choice of, booting into any operating system at power-up., , •, , Protecting or isolating files, to make it easier to recover, a corrupted file system or operating system installation., If one partition is corrupted, other file systems may not, be affected., , •, , Raising overall computer performance on systems, where smaller file systems are more efficient., , •, , Partitioning for significantly less than the full size, available can reduce the time for diagnostic tools such, as checkdisk to run., , Copa 181302, , Formatting, , Installing the Windows operating System, A hard disk needs to be partitioned (though not, mandatory) and formatted before you can store data, on it., Partitioning, A partition, sometimes also called a volume, is an area, on a hard disk that can be formatted with a file system, and identified with a letter of the alphabet. For example,, drive C on most Windows computers is a partition. the, first three partitions you create are primary partitions., These can be used to start an operating system. If you, want to create more than three partitions, the fourth, partition is created as an extended partition., An extended partition is a container that can hold one or, more logical drives. Logical drives function like primary, partitions except that they cannot be used to start an, operating system., Many computers are partitioned as a single partition that, equals the size of the hard disk. Partitioning a hard disk, into several smaller partitions is not required, but it can, be useful for organizing data on your hard disk., Creating more than one partition has the following, advantages:, •, , Separation of the operating system (OS) and program, files from user files., , •, , Having a separate area for operating system virtual, memory swapping/paging., , •, , Keeping frequently used programs and data near each, other., , Disk formatting is the process of preparing a data storage, device such as a hard disk drive, solid-state drive or, USB flash drive for initial use. It is the act of creating a, file system on a volume, so that the operating system, can store and retrieve data on that volume., Formatting of a disk is of two categories:, 1 Low-level formatting (i.e., closest to the hardware), marks the surfaces of the disks with markers, indicating the start of a recording block. It also, provides information about block checks done for, future use by the disk controller to read or write data., This is intended to be the permanent foundation of, the disk, and is often completed at the factory. A hard, disk needs to be partitioned and formatted before you, can store data on it, 2 High-level formatting creates the file system format, within a disk partition or a logical volume. This, formatting includes the data structures used by the, OS to identify the logical drive or partition's contents., This may occur during operating system installation,, or when adding a new disk., Installing the Windows operating System, The three basic types of windows installation procedures, are as follows:, •, , Install on a brand new disk or computer system, , •, , Erase the disk, format it, and install., , •, , Install into a new directory for dual-booting, , For the first two methods, it must be ensured that the, computer can boot from a DVD or any other removable, drive. To do this the drive boot order needs to be changed, in the BIOS. The latest Windows DVDs are bootable, and run the Setup program automatically. Then the, installation can be done by following the procedure step, by step as indicated on the subsequent screens as in, trade practicals., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.13, , Copyright @ NIMI Not to be Republished, , 37
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IT & ITES, Related Theory for Exercise 1.4.14 & 1.4.15, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., Format a hard drive, , Format hard drive partitions, It's important to understand about partitions before getting, started. A hard drive can be divided up into smaller, sections, called partitions. It's possible to format one, partition while leaving the others untouched., , Fig 1, , If it isrequired to format the entire hard drive and use the, entire capacity in one block, delete the partition, information., Format a hard drive from the BIOS?, , Copa 110101, , Many people ask how to format a hard disk from BIOS., The short answer is no., , There are many reasons why it is required to format a, hard drive, such as to install Windows fresh, to get rid of, a virus or malware or simply because a pc is refreshed, or cleaned up on selling., , If it is required to format a disk and you can't do it from, within Windows, create a bootable CD, DVD or USB flash, drive and run a free third-party formatting tool., One option is Darik's Boot and Nuke (DBAN), which is, free for personal use. This program will totally erase and, format your hard disk, allowing for a clean install of a, new OS, but the process cannot be undone., Fig 2, , The process can be different depending on whether it's, an only hard drive and whether there is a spare PC or, not., , Copa 110102, , It cannot be formatted, the hard drive on which Windows, is running. In order to do this, it is in need to boot the PC, from a Windows installation disc, a USB flash drive or, another bootable disc., Format a disk?, Formatting is the process of deleting all the data on the, hard drive, but beware of 'Quick Format' which leaves, all data in place and makes the drive appear to be empty., A quick format is ok if there is a brand new hard drive, or, need to reinstall Windows, but not if its disposing of the, disk or giving it to someone else., , DBAN is supposedly only able to create a bootable CD/, DVD-R, but if don't have any blank discs or a burner,, there is a workaround available in the form of a separate, third-party program., , A word of warning: make sure to have successfully, backed up any photos, videos, music and other, documents from the drive before formatting it. Although, deleted files can be recovered in some situations,, prevention is always better than cure., , Universal USB Installer will quickly and easily convert, the DBAN ISO image downloaded to run from a bootable, USB. Simply insert a blank USB flash drive, run the, Universal USB Installer setup program, and follow the, prompts., It will ask to scroll through and pick the Linux Distribution, want to install to USB (in this case, the latest version of, DBAN), followed by its location on the computer and the, letter of the USB drive like to install it to., , 38, , Copyright @ NIMI Not to be Republished
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Once that information is complete, click create., , Copa 191503, , To boot from this USB drive rather than usual boot device, (in most cases, this would be the hard drive), it have to, be changed some settings in the BIOS., In the BIOS, navigate to the boot order settings, and, change the primary boot device to the USB drive (it, shouldn't need to be plugged in to make this selection)., After saved the settings and exited the BIOS, insert the, bootable USB, restart the computer., , Copa 191505, , Fig 5, , Fig 3, , By default Quick Format is checked, and choose the file, system and allocation unit size as well as changing the, volume label (the drive's name). Typically, leave all, settings unchanged and click the Start button. In under a, minute the hard drive will be formatted., , Fig 6, , Copa 191504, , Fig 4, , It will treat the USB as another drive so to avoid, inadvertently wiping that as well, remove it after booted, into DBAN., Quick format a hard drive?, Yes, but don't use this method if want the data to be, permanently erased. A quick format doesn't delete the, data but instead erases only the pointers to the files., Windows Vista, 7, 8 and 10 have a built-in Disk, Management tool (see below), but the fastest way to, format a hard drive is to click the Start button, then, Computer and right-click on the hard drive to wipe. It, can't be formatted the drive on which Windows is installed, for obvious reasons., , Copa 191506, , The PC should automatically boot the DBAN software,, which will guide through the process of erasing the hard, drive, with options for different levels of data-wiping., , Choose NTFS as the file system if it isn't already selected, for Windows Vista, 7, 8 or 10 and ensure the Allocation, Unit Size is set to 'Default Allocation Size'., Using the Disk Management tool, Type diskmgmt.msc or Disk Management into the search, box in Vista, 7, 8 or 10 and then click on only result that, appears in the menu above, with the same name., This is the easiest way to launch Disk Management, but, also find it in the Control Panel if search for 'disk' and, select the 'Create and format hard disk partitions'., Disk Management isn't as powerful as a standalone, partition management tool, but it is still capable of, formatting data., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 39
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If select a size for the partition that's smaller than the total, capacity of the drive, say 500B on a 1TB drive, end up, with some unallocated space on the drive which can format, by repeating the process just completed., , Fig 7, , change partition size, Disk Management can be used to expand or shrink a, partition. Simply right-click on one and choose the, appropriate option from the menu that appears. If, shrinking, the partition will be checked to find out how, much empty space it contains., , If it is to install a new (additional) hard drive in a PC, it, might be a thing to wonder why it doesn't appear in Windows, Explorer. The reason is because it needs to be initialised, and formatted -which can be done in Disk Management., When the tool loads, it will analyse all of the computer's, drives and will prompt to initialise a new disk that it finds., , Fig 8, , Copa 191509, , Copa 191507, , Fig 9, , It's a little confusing as the numbers are displayed in MB, rather than GB, but it can be adjusted the amount of, space to shrink and the 'Total size after shrink' will be, updated, alsocan't shrink a partition beyond the point, where files are located - it may be able to free up space, by defragmenting the drive first., Conversely it can only expand a partition if there is, unused space on the drive. If not, the option will be greyed, out., , Copa 191508, , Resetting Windows, If PC is having problems and the user don't wish to lose, the personal files by wiping the hard drive, then it might, want to refresh or reset the PC which can be done in, Windows 8 and 10., If user looking to keep your personal files and settings,, but want to have a fresh Windows install, itsall want to, refresh the PC., , If the disk is larger than 2TB, opt for GPT (GUID Partition, Table). This setting also lets to create more than four, partitions., , Do note that a refresh will remove all programs and apps, installed on the machine, but will keep the Windowsdefault programs intact., , If don't see a prompt, look in the list of drives and see, one that says 'Not Initialized'. Right-click on it and choose, Initialize Disk., , A reset reinstalls Windows and deletes all files, settings, and programs, it is suggested performing this if have, previously backed up all the files and don't mind, transferring user's personal files., , Once that's done, right-click in the hatched Unallocated, space and choose New Simple Volume…, Follow the instructions, choosing how big to want the, partition to be (in MB - 1024MB = 1GB), and which drive, letter to assign (one will be chosen, but can opt to change, it if desired)., , 40, , Windows 10 has a slightly different approach and might, confuse those coming from Windows 8. Microsoft, removed the refresh option and has instead combined, the refresh and reset options into one setting., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished
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Copa 1915010, , Fig 10, , To find the option, open the Start Menu, click on Settings, > Update & security > Recovery > Get started (under, the Reset this PC option)., , 'Keep my files' saves personal files but deletes user, settings, drivers and programs, whilst also reinstalling, Windows 10., , Upon selecting the option, it will present with three, separate options:, , 'Remove everything' also gets rid of personal files and, 'Restore factory settings' does the same actions as, 'Remove everything', but also resets the PC to the version, of Windows which came with the machine., , •, , Keep my files, , •, , Remove everything, , •, , Restore factory settings (not available on all PCs), , This option will only be available to those who bought a, pre-built PC or laptop which came with Windows already, pre-installed., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 41
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IT & ITES, Related Theory for Exercise 1.4.16, COPA - Computer basics & Software installation, Troubleshooting computer, Objectives: At the end of this lesson you shall be able to, • state the basic steps involved in troubleshooting a PC, • explain the basic approach to solve a problem, • list the probable defects and symptoms in a faulty Computer, • analyse the causes for the complaints, • state the shortest path for servicing the defects., • list the probable defect and symptoms in the faulty Computer, • analyse the causes for the complaint “When windows is started, system runs surface test and goes to, safemode” with the help of a Problem Tree and TSC, Basic Troubleshooting, One of the difficulties while troubleshooting problems on, a PC is that in most cases they are not what they seem., The cause behind a frequent hanging of a PC may be due, to one of six or more well defined areas or a dozen of, unidentified problems. The problem could be due to, software or hardware. Even with years of experience and, training, PC technicians come out with troubleshooting, procedures that do not solve the real problem. For, example a personal computer running windows operating system with several i/o cards connected may freeze, the screen , mouse, and keyboard and take as long as 3, minutes before responding. After trying out with all the, options like replacing a memory module, installing new, parallel port and NIC drivers, the technician finally checks, the system logs to find that a vital operating system, library was corrupted and needed to be reinstalled. The, issue to be mentioned here is that if the technician used, a systematic approach to troubleshooting, the problem, would likely have been solved much sooner. Maintaining, a good troubleshooting plan certainly gives us the scope, to approach the problem in a more systematic and, scientific manner. A troubleshooting plan is nothing but, a written check list that we use for any problem. The, elements that should be included in any troubleshooting, plan are as follows, – Maintenance record, – Identification of possible causes, – Identification of possible solutions, – Application and testing of solutions, – Follow-up, In the maintenance record, record the hardware installed, in the PC when it is installed, all preventive maintenance, activities, all software updates or additions, and all, hardware installations and upgrades. Further any problems that occur and the actions you take to resolve them, should be recorded . when it comes to troubleshooting a, PC, with the maintenance record one can pin down a, problem and devise solution for it. The first entry in such, record should be a profile of the PC, which includes its, configuration, operating system, and the date each, component was installed., 42, , Such tables gives an idea of the type of information one, should include in the sytem configuration, as summerised, below:, – The processor’s make, model and speed., – Amount of system memory(RAM) and the memory, module type, size and configuration of the memory, – Hard disk size and the type of interface, – Make, model and speed of the compact disk (CD) or, digital versatile disk ( DVD) drive, – Memory size of the video or graphics adapter, – Make, model, type and speed of the modem, – The version number of the operating system, – A list of software applications installed on the PC, – A list of peripheral equipment attached to the PC,, indicating the port to which they are attached, The maintenance record should be updated each time any, maintenance work is carried over on the PC. Any time new, or replacement hardware is installed, record the activity, and update the system configuration. The activity entries, should include, – Date of the activity or changes made to the system, – The make, model and serial number of any hardware, removed or added to the PC, – The name, version and publisher of any software added, to the PC, – Detailed information on any configuration changes, made to the basic input/output system(BIOS) or other, configuration for the new device or software., Troubleshooting approach, For solving any problems associated with PC, first go, through the maintenance record of that PC and follow a, systematic procedure for isolating the problem. The, standard problem solving process includes the following, steps, Identify the problem: This is the most difficult part of the, process. To perform this step successfully collect all the, data about the problem, , Copyright @ NIMI Not to be Republished
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Identify possible causes: analyse all the symptoms of, the problem and try to list all the causes in order from the, most likely to the least likely., Identify possible solutions: identify solutions for each of, the causes that are identified. A possible cause could have, more than one possible solution., Analyze the possible solutions: if two solutions produce the same result, consider the one which is more, economic and apply the same., After following the above steps and on solving the, problem update the maintenance record and make, necessary entries into it. In some cases the problems, may be very clear and the solution is very transparent and, even in such cases try to follow the above mentioned steps, to make it a practice to follow the systematic approach., Whenever a problem occurs with a PC, while following the, steps, try to collect the information about the system by, answering questions such as, – Under what circumstances this problem cropped up?, – Were there any indications in the form of beep codes/, error messages or any clear symptoms?, – What softwares were active when the problem happened?, – Has it happened for the first time or occurred in the past, also?, – Were there any configuration changes made during, the session that required a restart that was not, performed?, Optimizing the PC:, A PC which was functioning absolutely well and developed, a symptom of slowing down or if it is unable to keep pace, with the demands of newer software, one of the possible, solutions is to consider updating or optimizing the PC to, enhance its performance. Optimization steps may cost, money , but many involve software you already own or, software readily available on the web., , they are installed out of order, but there is some benefit to, be gained from putting them in the proper sequence. On a, Pentium system, use PCI cards and avoid ISA cards, if, possible. All I/O adapters including video cards, sound, cards, NICs, modems and SCSI adapters are available for, the PCI expansion bus. Consult the motherboard documentation and install video card in the first PCI slot,, followed by the NIC, modem, and sound card, in that order., Optimizing the processor: One can speed up the processor in the following ways, – Replace it with a faster speed or higher level processor, – Use a utility from the processor manufacturer to apply, patches or fixes to the processor’s logic, – Overclock the processor, The requirement for replacing the processor with a higher, level or faster processor is that your motherboard and, chipset will support the new processor both logically and, physically. Logically the chipset and motherboard must, support the bus speed of the processor and have the, supporting circuits it requires. It is often much better to, replace the complete motherboard. Some times the manufacturer of the processor may release some utilities that, will improve some aspect of processor’s capabilities such, as video processing, buffer handling, caching and other, processor based functions. Overclocking a processor, means running a processor at speeds faster than it was, released to support. Most processors are capable of, running at speeds higher than their nominal speeds. The, nominal speed of a processor is the speed at which it has, been tuned to run with a certain chipset, motherboard,, cooling system, and other components of the PC. Raising, the speed of the processor can create heating problems on, the processor and lead to frequent system lockups,, memory problems and other issues., Troubleshooting sources of Non-software problems:, Any time pc fails for no apparent software reason, check, the following areas, , Optimizing the BIOS and Boot process:, , – Ensure proper AC power, , BIOS setup configuration includes many settings in the, CMOS. How quickly the system boots and performs, depends on the these settings. Enabling of valuable, features such as system caching or using the quick, POST process are very vital for optimum peroformance., , – Scan the PC for a computer virus, , Optimizing the hard disk: Windows ScanDisk and Disk, Defragmenter utilities are the best tools available for, optimizing the hard disk in terms of usage and access, speeds. ScanDisk is used to check a disk for errors and, repair them or remove unrecoverable areas of the disk, from the usage tables to prevent future errors. Similarly, Disk Defragmenter organizes data file fragments into a, more optimized and logical format that provides for, faster access times and less head movement., Optimizing the Expansion cards: The best way to, optimize I/O controllers and other expansion cards is to, install them in the correct order. No harm is done even if, , – Ensure that CPU fan is spinning, – Ensure proper connections of external I/O connectors, – Reseat the expansion cards and check the power and, data cables of internal devices, – Most of the boot problems are the result of a recent, change, check out the BIOS setup configuration data, – To install any new hardware or software, visit manufacturer’s web site for any known conflict or incompatibility, – Check for any resource conflict if any new hardware or, software is installed., The forth coming lessons on Troubleshooting PC are, provided with Problem Trees for different type of problems, which a user face normally. Each Tree with a specific, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 43
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problem gives scope to analyse the areas to be suspected, or looked into for fixing the problem. This lesson includes, a Problem Tree for a PC which is Dead with no display on, monitor., PROBLEM TREE : PT- 01, Observed symptom, , : Dead, , Additional symptom, , : No display, , PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”., Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , 44, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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SAFE MODE, SURFACE SCAN TEST, , HDD, BAD SECTORS, , OS, , Discuss the Troubleshooting chart (TSC-01) and Service flow sequence (SFS-01) for the complaint “When, windows is started system runs surface test and goes to safemode” referring to exercise 2.33, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 45
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PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , Observed symptom, , PROBLEM TREE : PT- 03, : DVD drive can’t read, , Additional symptom, , :, , 46, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.17, COPA - Computer basics & Software installation, Application softwares, Objective: At the end of this lesson you shall be able to, • describe various software types., Application software, Application software is a term which is used for software, created for a specific purpose. It is generally a program, or collection of programs used by end users. It can be, called an application or simply an app., In fact all the software other than system software and, programming software are application software., Application software definition, A software which is developed to help the user to perform, specific tasks is called application software., The different types of application software include the following:, Application Software Type, , Examples, , Word processing software, , MS Word, WordPad and Notepad, , Database software, , Oracle, MS Access etc, , Spreadsheet software, , Apple Numbers, Microsoft Excel, , Multimedia software, , Real Player, Media Player, , Presentation Software, , Microsoft Power Point, Keynotes, , Enterprise Software, , Customer relationship management system, , Information Worker Software, , Documentation tools, resource management tools, , Educational Software, , Dictionaries: Encarta, BritannicaMathematical:, MATLABOthers: Google Earth, NASA World Wind, , Simulation Software, , Flight and scientific simulators, , Content Access Software, browsers, , Accessing content through media players, web, , Application Suites, , OpenOffice, Microsoft Office, , Software for Engineering and Product Development, , IDE or Integrated Development Environments, , Copyright @ NIMI Not to be Republished, , 47
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There are various different types of application software, such as licensed, sold, freeware, shareware and open, source., Application software's either need to be installed or can, run online. Application software's can also be distinguished, on the basis of usage into the following:, •, , Utility programs, , •, , Generic programs, , •, , Integrated programs, , •, , Specific software, , •, , Bespoke software, , •, , Word processing software, , 48, , •, , Desktop publishing software, , •, , Spreadsheet software, , •, , Database software, , •, , Presentation software, , •, , Internet Browsers, , •, , Email Programs, , •, , Graphic Programs (Pixel based), , •, , Graphic Programs (vector based), , •, , Communication software: Communication through, audio, video or chat based means, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.17, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.18&1.4.19, COPA - Computer basics & Software installation, Bluetooth devices, Objectives : At the end of this lesson you shall be able to, • describe the meaning of Bluetooth, • describe the method of using Bluetooth, • list the major applications of Bluetooth., Introduction:, Bluetooth is a wireless technology standard for, exchanging data over short distances (using shortwavelength UHF radio waves in the range 2.4 to 2.485, GHz) from fixed and mobile devices, and building, personal area networks (PANs). It is a standard wirereplacement communications protocol primarily designed, for low-power consumption, with a short range based on, low-cost transceiver microchips in each device., It can connect up to eight devices (items of electronic, equipment) at the same time. The chip can be plugged, into items such as computers, digital cameras, mobile, phones and faxes. Bluetooth is particularly convenient, in certain situations - for example, when transferring files, from one mobile phone to another without cables., Sending music and photos between a PC and a mobile, phone is another useful application., Because the devices use a radio (broadcast), communications system, they do not have to be in visual, line of sight of each other, however a quasi optical, wireless path must be viable., Range is power-class-dependent, but effective ranges, vary in practice varying from 10 to 100 m., The name 'Bluetooth' reflects the Scandinavian origins, of the technology. It is named after a 10th century Danish, viking, King Harald Blåtand (translating as 'Bluetooth' in, English).He united and controlled Denmark and Norway,, hence the association of uniting devices through, Bluetooth., , When devices like mobile phones, laptops, tablets etc., enable Bluetooth the Bluetooth icon is on., To establish a Bluetooth connection:, 1 Find the file you wish to send., 2 Select the option to send it via Bluetooth - your device, will search for other devices within range and display, them., 3 Scroll to the device you wish to connect with and, select it., 4 If the other device needs 'pairing', you will need to, enter a passcode - a bit like a PIN number - and make, sure it is entered on the other device., When the connection is established, the data will start to, send. You do not need worry about a clear line of sight, between devices., List of Bluetooth applications, Some of the Bluetooth applications are as follows:, Wireless control of and communication between a mobile, phone and a handsfree headset.(Refer fig. 1), , Fig 1, , To use Bluetooth, the device must be Bluetooth enabled., For this purpose a device called "Dongle"may be used., A dongle is a device that plugs into the computer to, enable it to use Bluetooth. Every manufacturer of, compatible devices will have their own instructions for, accessing Bluetooth. For detailed instructions you will, need to see the manual, but as a general guide:, To set up Bluetooth:, (Identify the blue tooth icon on devices.), 1 Turn on, or enable, Bluetooth. Ensure your device is, 'visible' and not 'hidden', so other nearby devices can, pick up the signal., 2 Give your device a name to identify it when, connecting to other compatible equipment., , Copa 118290A1, , Using Bluetooth, , • Wireless control of and communication between a, , mobile phone and a Bluetooth compatible car stereo, system., , • Wireless control of and communication with tablets, and speakers such as iPad and Android devices., , • Wireless networking between PCs in a confined space, and where little bandwidth is required., , • Wireless communication with PC input and output, , devices, the most common being the mouse,, keyboard and printer., , Copyright @ NIMI Not to be Republished, , 49
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• Transfer of files, contact details, calendar, , appointments, and reminders between devices with, OBEX(Objects exchange)., , • Replacement of previous wired RS-232 serial, , communications in test equipment, GPS receivers,, medical equipment, bar code scanners, and traffic, control devices., , Wi-Fi:, Wi-Fi is a popular wireless networking technology. WiFi stands for "wireless fidelity". The Wi-Fi was invented, by NCR corporation/AT&T in Netherlands in 1991. By, using this technology we can exchange the information, between two or more devices. Wi-Fi has been developed, for mobile computing devices, such has laptops, but it is, now extensively using for mobile applications and, consumer electronics like televisions, DVD players and, digital cameras. There should be two possibilities in, communicating with the Wi-Fi connection that may be, through access point to the client connection or client to, client connection. Wi-Fi is a one type of wireless, technology. It is commonly called as wireless LAN (local, area network). Wi-Fi allows local area networks to, operate without cable and wiring. It is making popular, choice for home and business networks. A computer's, wireless adaptor transfers the data into a radio signal, and transfers the data into antenna for users., , Fig 1, , • Wireless bridge between two Industrial Ethernet, networks., , • Wireless controllers in gaming consoles., • Personal security application on mobile phones for, prevention of theft or loss of items. The protected, item has a Bluetooth marker (e.g., a tag) that is in, constant communication with the phone. If the, connection is broken (the marker is out of range of, the phone) then an alarm is raised., , And can now generate a system within Resorts, library,, schools, colleges, campus, personal institutes, as well, as espresso stores as well as on the open public spot to, help to make the company much more lucrative as well, as interact with their own customer whenever. Wi-Fi, compatibility can make surf with stare to company using, their inspiring cable television much a smaller amount, force down., The radio signals are transmitted from antennas and, routers that signals are picked up by Wi-Fi receivers,, such has computers and cell phones that are ready with, Wi-Fi cards. Whenever the computer receives the signals, within the range of 100-150 feet for router it connect the, device immediately. The range of the Wi-Fi is depends, upon the environment, indoor or outdoor ranges. The, Wi-Fi cards will read the signals and create an internet, connection between user and network. The speed of the, device using Wi-Fi connection increases as the computer, gets closer to the main source and speed is decreases, computer gets further away., , Copa 1121802, , Copa 1121801, , Fig 2, , Working Principle:, Wi-Fi is a high speed internet connection and network, connection without use of any cables or wires. The, wireless network is operating three essential elements, that are radio signals, antenna and router. The radio, waves are keys which make the Wi-Fi networking, possible. The computers and cell phones are ready with, Wi-Fi cards. Wi-Fi compatibility has been using a new, creation to constituent within the ground connected with, community network. The actual broadcast is connected, with in sequence in fact it is completed by way of stereo, system surf as well as the worth of wires with monitor to, classification prone. Wi-Fi allows the person in order to, get access to web any place in the actual provided area., , 50, , Security:, Security is impartment element in the Wi-Fi technology., Security is our personal decision but having a wireless, connection we should pay attention to protect our private, details. We can connect easily to unsecured wireless, routers. The problem is any one is connected to, thewireless router using the data like download games,, download apps and planning terrorist activities, shirring, illegal music and movie files etc. So it is necessary to, provide security to the wireless technologies based, devices., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.18 & 1.4.19, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.20, COPA - Computer basics & Software installation, DVDs, CDs and burning DVDs, Objectives : At the end of this lesson you shall be able to, • describe the features of CDs & DVDS, • describe the main formats of DVDs, • describe DVD burning, • describe the features of CDs., Introduction, DVD (sometimes called as "digital video disc" or "digital, versatile disc") is a digital optical disc storage format., DVDs can be usedwith many types of players, including, PCs and standalone players., These discs are known as DVD-ROM, because data can, only be read and not written or erased. Blank recordable, DVD discs (DVD-R and DVD+R) can be recorded once, using a DVD recorder and then function as a DVD-ROM., Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM), can be recorded and erased multiple times., DVD features and formats, DVDs are used in DVD-Video consumer digital video, format and in DVD-Audio consumer digital audio format., They can also be used in a special AVCHD format (, Advanced Video Coding High Definition) often used with, AVCHD format camcorders. DVDs containing other types, of information may be referred to as DVD data discs., A typical recordable DVD can hold about 4.7 gigabytes, (GB). However, the total amount of disc space that you, can use to burn files to the disc is less than the amount, that's often listed on the disc itself. This is because the, disc capacity is calculated differently when it's used in a, computer. For example, a typical DVD-R that has a listed, disc capacity of 4.7 GB can only store about 4.37 GB of, data on the disc. DVDs offer a storage capacity of, approximately 4.7 GB. DVD discs do not deteriorate over, time and are unaffected by magnetic fields., The type of recordable disc to be used depends on a, few different factors, such as:, , • The types of recordable discs that work with the disc, burner., , • The disc drive on the computer or device will read, the disc after it is burned., , • The total size of all the files that will be burned on to, a disc., , DVD burning, The process of recording source material onto an optical, disc (CD or DVD) is called burning / writing or optical, disc authoring.Creating an optical disc usually involves, first creating a disk image with a full file system designed, for the optical disc, and then actually burning the image, to the disc. Many programs are available as bundled, applications to create the disk image and burn the files., , The speed at which a DVD can be written is expressed, as a multiplier: 16X means 16 times faster than just, playing it. Speeds upto 52X are also very common., CD or DVD formats, For burning DVDs, the two main disc formatsin use are:, , • Live File System and, • Mastered disc formats., Live File System format :, Discs that use the Live File System format are often, more convenient because you can copy selected files, immediately and as often as you want, just like you can, with a USB flash drive. This is convenient if you want to, keep a disc in your CD, DVD, or Blu ray Disc burner and, copy files whenever the need arises. In this format you, can copy and erase files over and over again. However,, the Live File System optical disc format is only readable, by Windows 7, Windows Vista, and Windows XP, systems. These discs are not blank after they're, formatted., Discs formatted in this format have the option name in, the Burn a Disc dialog box: "Like a USB flash drive.", Mastered disc formats:, If we want to create an optical disc that can be used to, transfer data files to older versions of the Windows, operating system or even to another operating system,, weneed to use the Mastered optical disc format. Also if, we want to burn music or pictures and use the disc in, regular CD, DVD, or Blu ray Disc players that can play, MP3 files and show digital pictures, we should use the, Mastered optical disc format., The Mastered format works just like burning CDs in, Windows XP. In other words, when we write the disc, we, copy a file or a group of files to the optical disc all at, once. Once this is done, the disc is closed and we cannot, copy more files to the disc nor can we delete the existing, files.Hence it is recommended not to copy files, immediately; it is a good practice to assemble the entire, collection of files that needed to be copied to the disc, and then burn them all at once., Discs formatted with the Mastered option have the option, in the Burn a Disc dialog box: "With a CD/DVD player.", There are many types of tools available to create data,, music, video and audio discs. We can also create, , Copyright @ NIMI Not to be Republished, , 51
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backups that span across multiple discs, rip music tracks, from Audio CDs and create or burn disc images in, different formats. They may also provide features like, automatic audio conversion from WAV, MP3, FLAC,, WMA files, disc copying, compressed file backup and, restore, disk erasing, VCD/SVCD support, project burning, etc.., , The following formats are part of the present day Bluray Disc specification:, , Blu - ray Discs, , 3, , Blu-ray, also known as Blu-ray Disc (BD) is the name of, a new optical disc format that is rapidly replacing DVD., The format was developed to enable recording, rewriting, and playback of high-definition video (HD), as well as, storing large amounts of data. The format offers more, than five times the storage capacity of traditional DVDs, and can hold up to 25GB on a single-layer disc and 50GB, on a dual-layer disc., , 1 BD-ROM - read-only format for distribution of HD, movies, games, software, etc., 2 BD-R - recordable format for HD video recording and, PC data storage., BD-RE - rewritable format for HD video recording, and PC data storage., , At present, a single-layer disc can hold 25GB and a duallayer disc can hold 50GB. Over 9 hours of high-definition, (HD) video on a 50GB disc. About 23 hours of standarddefinition (SD) video on a 50GB disc., , The name Blu-ray is derived from the underlying, technology, which utilizes a blue-violet laser to read and, write data. The name is a combination of "Blue" (blueviolet laser) and "Ray" (optical ray). They are referred to, as "Blu-ray" discs or BDs., , 52, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.20, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.21, COPA - Dos & Linux operating systems, Comand line interface with DOS, Objectives: At the end of this lesson you shall be able to, • describe the hierarchical directory system in DOS, • use dos commands to create directories and subdirectories, • use dos commands to change and list directory, • use dos commands to access specific files., Hierarchical Directory System: Hierarchy in simple, terms, is, organisation or an arrangement of entities., Entities can be anything such as objects, files, people,, ideas, or any other thing., Arrangement refers to, for example, Currency can be, arranged by denomination. Pebbles can be arranged by, their size ., There are many other ways to organize entities besides, hierarchically. But, hierarchical organization is special, because by this arrangement you can name each entity, by its relationship to other entities., In DOS, entities are the Directories in a directory system., Here, the hierarchy begins with the essential core or root, entity. For instance, in a family tree, we may consider, great-great-grand father who was the root cause of our, existence as the core entity. In DOS , this core entity is, referred to as the the root directory., As in the example considered above, if we consider, great-great-grand father as the root directory, then, greatgrand father, grand father, father are referred as sub, directories. So the directories under the root directory are, called subdirectories in DOS. These subdirectrories can, trace their paths back to the root directory., , In a family tree, say, Govinda is the son of Rajappa, who, is son of Ramappa who is son of Venkappa. Venkappa, is the head or root of the family tree for Govinda., One can create many directories from the root. The root, will then be the parent of each of these directories. You, can also create subdirectories that stem from other, subdirectories that stem from other subdirectories and so, on. These new subdirectories have a subdirectory as, their parent directory. How subdirectories are arranged, hierarchically from the root is illustrated in Fig 1. The, DOS directory system is often called a tree-structured, directory system., Three levels of subdirectories are represented in Fig 1., Regardless of the number of levels, the relationship of, the subdirectories is important. Each subdirectory, as, well as the root directory, can contain user files. Two files, can have the same file name and extension as long as the, files reside in different directories. This is because, DOS, needs to know which of two same-named files your, command specifies. For this, DOS needs the name of the, directories,starting from the root, that lead to the desired, file. This sequence of directory names leading to a file is, called a path., , The DOS hierarchical file system is called a tree-structured, file system. At the base of this tree structure is the root, directory., Fig 1, , ROOT, , a1, , LEVEL - 2, , LEVEL - 3, , B, , A, , LEVEL - 1, , a11, , a2, , a21, , D, , C, , c1, , c2, , c21, , Copyright @ NIMI Not to be Republished, , a22, 53
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A path is a chain of directory names that tell DOS how to, find a file that you want. Each directory is seperated from, the other by a ‘ \ ’ character. This ‘ \ ’ is referred to as the, DOS directory delimiter. A files full path name including, the drive specifier ( C: or D: etc.,) is the absolute indicator, of where the file is located. Typical path notation are, given below;, D:\Animals\Domestic\Pets\Dog.txt, C:\Admin\Accounts\Tours\Bata.txt, Further details of path and directory structure, will be discussed at appropriate lessons., DOS COMMANDS, 1, , MKDIR, , Makes or Creates a new Directory., , MKDIR\Drivers, Or, MD\Drivers, C:\Devices>MD \Printers, This instruction creates a subdirectory by name Printers, under the current drive C:. Note that although the, command is issued from another subdirectory named, devices, the newly created subdirectory Printers does, not get created under the directory Devices but directly, under the root C:. This may be verified by issuing DIR, command under C:\ and under C:\Devices., To create a subdirectory under the directory Devices the, instruction will be,, C:\Devices>MD Printers, Discuss the following different varieties of creating, directories:, , or, MD, , C:\Devices\Printers>MD C:\Devices\Plotters, , Syntax, MKDIR C:path\dirname, Or, , 2, , CHIDR or CD, , Changes or shows the path of the current directory., Syntax, , MD d:path\dirname, , CHIDR d: path, , Where,, C: is the disk drive for the sub directory, path\ indicates the path to the directory that will, hold the subdirectory being created., dirname is the name of the subdirectory being, creating., Switch, (None), Important Notes, – MKDIR or its short form MD makes new, subdirectories under the selected root directory., – It is possible to create as many subdirectories as, you want , but remember: DOS accepts no more, than 63 characters, including backlashes, for the path, name., – Do not create too many levels of subdirectories and, with long names., – You cannot create a directory name that is identical to, a file name in the current directory., For example, if you have a file named FLIES in the, current directory, you cannot create a subdirectory by the, name FLIES in this directory. However, if the file FLIES, is given an extension FLIES. DOC , then the names will, not conflict and you can create a subdirectory by name, FLIES., Examples, , Or, using the short form:, CD d : path, D : path are valid disk drive and directory names., Switch, (None), You have two methods for maneuvering through, the hierarchical directories with CD: (1) starting, at the root , or top, directory of the disk and, moving down, or (2) starting with the current, directory and moving in either direction., To start at the root directory of a disk, you must begin the, path with the path character (\), as in \ or B:\. When DOS, sees \ as the first character in the path, the system starts, with the root directory. Otherwise, DOS starts with the, current directory., Changing Drives: Computer will have built in memory,, the hard disk and it will also have provision to store/read, data from floppy disk, compact disk etc. Every disk is, identified by a name such as C drive, A drive, B drive etc., C drive is represented by C: and A drive is represented, by A: and so on. DOS allows to change from current or, default drive by typing the letter identification of disk, drive desired followed immediately by a colon as shown, in the example below:, C\> a:, , To create the subdirectory by name Drivers under the, current drive, the instruction will be,, 54, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished
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This command instructs to change control from C drive to, D drive., , H Hidden files, , If the disk drive is not accessed due to non availability of, floppy or any other reason, DOS will display an error, message, , A Files ready to archive - Prefix meaning “not”, , S System files, / O List be files in sorted order., sorted N By name (alphabetic), , Not ready error reading drive A, , S By size (smallest first), , Abort, Retry, Fail ?, , E By extension (alphabetic), , It is required to press either A,R or F keys, which are, defined below, , D By date & time (earliest first), G Group directories first, , A Directs DOS to abort the command that was, responsible for the error. If this option is selected, DOS will terminate the command and redisplay, prompt., , - Prefix to reverse order, C By compression ratio (smallest first), , R Directs DOS to retry the command that caused the, error. In most cases this option is selected to correct, the the problem that was causing the error. (Floppy, disk might not be inserted)., , /S, , Displays files in specified directory and all, subdirectories., , /B, , F Directs DOS to ignore the error and attempt to, continue processing. In some cases DOS will have, an error when it reads a portion of disk., , Uses bare format (no heading information or, summary)., , /L, , DOS COMMAND, DIR, , Displays a list of files and subdirectories in, a directory., , Syntax, DIR C:path/filename [/P] [/W] [/A[[:]attribs]] [/O[[:]sortord]], [/S] [/B] [/L] [/C[H]], , Where,, –, , C: is the disk drive holding the directory for, displaying list of files and subdirectories, , –, , path/ specifies directory and/or files to list., , –, , filename specifies file or list of files to display,, if file name is not specified all the files in the, directory will be listed., , –, , [/P] [/W] ......... specifies the switches for, formatting the output., , Switch, /P, , Pauses after each screenful of information and, waits to press any key. On pressing any key, another screenful or remaining information will, be displayed. Command is DIR/P, , /W, , Uses wide format of 80-column to display file, names only and information about file size,, date, and time is not displayed. Command is, DIR/W, , /A, , Displays files with specified attributes., , Uses lowercase., , / C[H] Displays file compression ratio; /CH uses host, allocation unit size., Important Notes:, – In the directory listing similar files can be listed by, using wildcards (* and ?), where (*) star and (?), question mark are called wild characters or wild cards., * can replace remaining charecters and ? can replace, any single character., – When DIR is used without parameters or switches, It, displays the disks volume label and serial number;, one directory or filename per line, including the file, size in bytes, and the date and time the file was, modified; and the total number of files listed, their, cumulative size and the free space ( in bytes), remaining on the disk., Examples, DIR *.txt, *.txt instruction will list all files having txt extension, in the specified directory., DIR ???T.*, ???T instruction will search for files having four, characters which ends with T like TEST,, REST etc. And * instructs that these files may have, any extension like .txt, .dat etc., , attribs, D Directories, R Read-only files, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished, , 55
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IT & ITES, Related Theory for Exercise 1.5.22, COPA - Dos & Linux operating systems, Methods to display the contents of a text file, Objectives: At the end of this lesson you shall be able to, • use DOS commands to display the contents of a text file, • use DOS commands to copy,rename,delete and undelete files., DOS Commands, , Examples, , TYPE Displays the contents of a text file., , 1 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt, , Syntax, , C:\COPA\DOS\PRACT_3 is the path to the file, TEST.txt and TYPE is the command to be executed, by DOS., , TYPE C:path/filename, Where,, –, , C: is the disk drive holding the file for displaying., , –, , path/ Specifies the location of file for displaying., , –, , filename specifies file to display., , Switch, , 2 C:\>TYPE C:\COPA\DOS\PRACT_3\>TEST1.txt, This results in the same output as in example1. While, working from C: (C drive) this command can be, issued with out changing the directories., 3 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt | MORE, This will also result in the same output but displayed, screen page by screen page. Screen page can be, changed on press of any key. Along with MORE, another character is prefixed ‘|’ this called the piping, command, Which will route the output of TYPE, command to another command MORE and the, MORE filter outputs the information., , (none), Important notes:, – TYPE command provides a quick way to display, contents of an ASCII file with out having to use, another program. The file is stored on the disk as, ASCII (American Standard code for Information, Interchange) text. which is standard way the computer, translates binary ( ones and zeros) into letters,, numbers & symbols. If the information is not stored in, the ASCII format, on using TYPE command the, information will look like gibberish., – On issuing command DOS will look in drive specified,, moves into the path to reach the filename specified., Then it simply translates ASCII format into the, characters, numbers and symbols and displays on, the monitor. The video monitor can show 24 lines of, information only. if the file contains more than 24, lines starting lines can not be seen since the type, command simply scrolls all information on to the, screen. Scrolling can be controlled by pressing, Control + S keys together (on holding control key, press S key and release both the keys is called as, Control + S) scrolling of information will stop on the, monitor. After viewing the contents on the screen any, key can be pressed to scroll through the remaining, contents. To view the contents of the file screen page, by screen page, MORE command can also be used., which will stop the scrolling of information on the, screen exactly after a screen page and in the screen, page at 24 line a prompt message — More— is, displayed. After pressing any key another screen, page will be displayed. MORE is a filter e.g. itis a, program that manipulates the stream of standard, characters to the file to the standard output (monitor), screen page by screen page., , 56, , Renaming of file(s), RENAME, Or, , This command allows to change, the name of a file., , REN, Syntax, REN C: PATH\filename1.ex1 filename2.ex2, Where,, – C: is the disk drive holding the file for displaying., – PATH/ Specifies the location of file for displaying., – filename1.ex1 is the file to be renamed, – filename2.ex2 is the new filename, Important Notes:, – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be renamed., – A valid file name with appropriate extension is to be, given for new filename., – Wild characters are permitted in the file names by, which required group of files can be renamed., , Copyright @ NIMI Not to be Republished
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– Only file names will be changed and contents remain, same., – If attempted to change a file name to a name that, already exists in the directory., DOS prompts an error message, , Instructor shall discuss the simple switches, with at least two examples in each case ., For further details on COPY command switches, refer any tutorial or hand book on DOS, Important Notes:, , Duplicate file name or file not found, – If a invalid file name or the new name is not given,, then also DOS prompts an error message, Rules for the file names., – A File name must have 1 to 8 characters., – An optional extension of 1 to 3 characters, – A period (.) between the name and extension name,, if extension is used, – All letters from A through Z ( lower case letters are, automatically transferred to uppercase), 0 to 9, numbers and special characters & symbols $ # & @, ! ^ ( ) _ - { } ‘ ~ are permitted in the file name., , – DOS command COPY can duplicate one or more, files. In the same directory with different names or, from one directory to other directory either in the, same name or in different name., – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used., – Exact file name with extension is to be given for the, file to be copied, – A valid file name with appropriate extension is to be, given for new copied filename, , – The control characters such as Esc, Del, or space bar, cannot be used in the file name., , – Wild characters are permitted in the file names by, which required group of files can be copied, , – The characters + = / [ ] : ; ? * < > : are not permitted., , – On copying, both source and target files will have, same contents., , – Each file name in a directory must be unique., Examples:, , – Copy overwrites the target file with the same name, , TEST2.txt, , – Copy will not allow to copy a file to it self that is source, and target files should not be same, , C:\COPA\DOS\PRACT_3\ is the drive and path to the, TEST2.txt file, TEST2.txt is the file name to be renamed, , – If the destination file name is not specified while, concatenation the first file name will become the, destination name. After the first file name, additional, source files must be preceded by a plus (+) sign., , CHECKED.txt is the new filename, , Example, , 1 C:\COPA\DOS\PRACT_3\>REN, CHECKED.txt, , 2 C:\COPA\DOS\PRACT_3\>REN *.pic *.jpg the pic, extension will be changed to jpg extension files., Copying files:, COPY Copies one or more files to another location., Syntax, COPY [/A | /B] source [/A | /B] [+ source [/A | /B] [+ ...]], [destination[/A | /B]] [/V] [/Y | /-Y] source specifies the file, or files to be copied. Destination specifies the directory, and/or filename for the new file(s)., Switches, /A, , Indicates an ASCII text file., , /B, , Indicates a binary file., , /V, , Verifies that new files are written correctly., , /Y, , Suppresses prompting to confirm you want to, overwrite an existing destination file., , /-Y Causes prompting to confirm you want to overwrite, an existing destination file., , 1 C:\COPA\DOS\PRACT_3\>COPY, TRIAL.txt, , TEST2.txt, , With the above command C:\COPA\DOS\PRACT_3, directory TEST2.txt file will be copied as TRIAL.txt, file in the same directory. On listing the directory both, the files will have same details and on viewing the, contents of both the file will be same. After copying, DOS prompts a message 1 file copied, 2 C:\COPA\DOS\PRACT_3\>COPY *.bmp *.pic, With the above command C:\COPA\DOS\PRACT_3, directory all files with bmp extension file will be, copied as pic extension files in the same directory., While copying DOS prompts the name of file it has, copied and after completion of copying it prompts the, number of files copied., 3 C:\COPA\DOS\PRACT_3\>COPY, C:\COPA\DOS\PRACT_4\, , *.pic, , All files with pic extension in C:\COPA\DOS\PRACT_3, directory will be copied to C:\COPA\DOS\PRACT_4, directory with same name & extension., Using *.* after the copy command will copy all files, with all extension to the destination., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 57
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Copy concatenating: Multiple file can be combined to, form a single file by use of + between the source files and, is called, as concatenation, Example 4 C:\COPA\DOS\PRACT_3\ COPY TEST2.txt, + TRIAL.txt CONCAT1.txt, With the above command TEST2.txt and TRIAL.txt will, be combined and CONCAT1.txt file will be created which, will have the contents of first two source files., Deleting file, DEL, , Deletes the files specified., , or, Erase, Syntax, DEL C:path/filename [/P], ERASE C:path/filename [/P], Where,, –, , C: is the disk drive holding the file to be deleted., , –, , path/ Specifies the location of file to be deleted., , –, , filename is the file to be deleted, , Switch, /P Prompts for confirmation before deleting the specified, file. Using the /P switch, If the /P switch is used, DEL displays the name of a file, and prompts with a message in the following format:, filename, Delete (Y/N)?, Press Y to confirm the deletion, N to cancel the deletion, and display the next filename (if a group of files are, specified), or CRTL+C to stop the DEL command., Important Notes, – If the drive is not specified current disk drive will be, used, – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be deleted, , The following command is given for deleting all the files., del *.*, DEL displays the following prompt:, All files in directory will be deleted! Are you sure (Y/N)?, Press Y and then ENTER to delete all files in the, current directory, or, press N and then ENTER to cancel the deletion., –, , Directories can not be removed with DEL command, a separate command is available for removing the, directory., , – Once the file is deleted it can not be recovered if the, memory space is occupied by a new file. If accidentally, file (s) are deleted immediately it can be recovered, by using utility command., – The space occupied by the deleted file on the disk or, diskette is freed., – Check for the typographic errors in the file names, before the press of enter key to activate delete, command, Example, 1 C:\COPA\DOS\PRACT_3\>DEL TEST2.txt, With the above command TEST2.txt file will be, deleted from the C:\COPA\DOS\PRACT_3 directory., On listing the directory TEST2,txt will not be available., 2 C:\COPA\DOS\PRACT_4\>DEL *.txt, With, the, above, command, in, the, C:\COPA\DOS\PRACT_4 directory all files with txt, extension will be deleted., 3 C:\COPA\DOS\PRACT_3\TEMP \> DEL *.*, All files with any extension in, C:\COPA\DOS\, PRACT_3\TEMP directory will be deleted., Recovering deleted files:, UNDELETE, , delete protection facility, , Syntax, UNDELETE C:path/filename [/DT | /DS | /DOS], , – Wild characters are permitted in the file names by, which required group of files can be deleted, , UNDELETE [/LIST | /ALL | /PURGE[DRIVE] | /, STATUS | /LOAD | /UNLOAD, , – On deleting, files name(s) will be removed from the, directory., , /UNLOAD | /S[DRIVE] | /T[DRIVE]-entrys ]], , – All the files in a directory can be deleted by typing the, DEL command followed by [drive:]path. Wildcard, also can be used (* and ?) to delete more than one file, at a time. However, Wildcards should be used, cautiously with the DEL command to avoid deleting, files unintentionally., , 58, , Where,, –, C: is the disk drive holding the files to be, undeleted., –, , path/ Specifies the location of file to be undeleted., , –, , filename is the file to be undeleted, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished
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Important Notes:, , Switches, /LIST, , Lists the deleted files available to be, recovered., , /ALL, , Recovers files without prompting for, confirmation., , /DOS, , Recovers files listed as deleted by, MS-DOS., , /DT, , Recovers files protected by Delete, Tracker., , /DS, , Recovers files protected by Delete, Sentry., , /LOAD, , Loads Undelete into memory for, delete protection., , /UNLOAD, , Unloads Undelete from memory., , /PURGE[drive], , Purges all files in the Delete Sentry, directory., , /STATUS, , Display the protection method in, effect for each drive., , /S[drive], , Enables Delete Sentry method of, protection., , /T[drive][-entrys], , Enables Delete Tracking method of, protection., , Once a file is deleted from disk, it may not be possible, to retrieve it. Although the UNDELETE command can, retrieve deleted files, it can do so with certainty only if, no other files have been created or changed on the disk., If a file is accidentally deleted and it is required to, keep, stop what all other activities on the computer and, immediately use the UNDELETE command to retrieve, the file., Example, 1 C:\COPA\DOS\PRACT_3\>UNDELETE TEST2.txt, With the above command TEST2.txt file will be, recovered. On listing TEST2.txt file will be available, in C:\COPA\DOS\PRACT_3 directory., 2 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE, With the above command multiple files can be, recovered. DOS will prompt for confirmation of, undeletion of each file and asks to type the first letter, of the file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen ., 3 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE /ALL, With the above command multiple files can be, recovered. DOS will not prompt for confirmation of, undeletion of each file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 59
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IT & ITES, COPA - Dos & Linux Operating System, , Related Theory for Exercise 1.5.23, , Introduction to Linux operating system, Objectives: At the end of this lesson you shall be able to, • overview of linux, • define futures of linux, • explain application area of linux, • describe about kernel., Overview of Linux, , Where is Linux?, , The operating system, , One of the most noted properties of Linux is where it can, be used. Windows and OS X are predominantly found on, personal computing devices such as desktop and laptop, computers. Other operating systems, such as Symbian,, are found on small devices such as phones and PDAs,, while mainframes and supercomputers found in major, academic and corporate labs use specialized operating, systems such as AS/400 and the Cray OS., , Developers need special tools (like the compilers and, command lines found in GNU) to write applications that, can talk to the kernel. They also need tools and applications, to make it easy for outside applications to access the, kernel after the application is written and installed., This collective set of tools, combined with a kernel, is, known as the operating system. It is generally the lowest, layer of the computer's software that is accessible by the, average user. General users get to the operating system, when they access the command line., Linux provides powerful tools with which to write their, applications: developer environments, editors, and, compilers are designed to take a developer's code and, convert it to something that can access the kernel and, get tasks done., Like the kernel, the Linux operating system is also, modular. Developers can pick and choose the operating, tools to provide users and developers with a new flavor of, Linux designed to meet specific tasks., Introduction to Linux, Linux (pronounced Lih-nucks) is a UNIX-like operating, system that runs on many different computers. Although, many people might refer to Linux as the operating, system and included software, strictly speaking, Linux is, the operating system kernel, which comes with a, distribution of software., Linux was first released in 1991 by its author Linus Torvalds, at the University of Helsinki. Since then it has grown, tremendously in popularity as programmers around the, world embraced his project of building a free, operating system, adding features, and fixing problems., Linux is popular with today's generation of computer, users for the same reasons early versions of the UNIX, operating system enticed fans more than 20 years ago., Linux is portable, which means you'll find versions, running on name-brand or clone PCs, Apple Macintoshes,, Sun workstations, or Digital Equipment Corporation, Alpha-based computers. Linux also comes with source, code, so you can change or customize the software to, adapt to your needs. Finally, Linux is a great operating, system, rich in features adopted from other versions of, UNIX., 60, , Linux, which began its existence as a server OS and Has, become useful as a desktop OS, can also be used on all, of these devices. ‚ÄúFrom wristwatches to, supercomputers,‚Äù is the popular description of Linux', capabilities., The future of Linux, Linux is already successful on many different kinds of, devices, but there are also many technological areas where, Linux is moving towards, even as desktop and server, development continues to grow faster than any other, operating system today., Linux is being installed on the system BIOS of laptop and, notebook computers, which will enable users to turn their, devices on in a matter of seconds, bringing up a, streamlined Linux environment. This environment will have, Internet connectivity tools such as a web browser and an, e-mail client, allowing users to work on the Internet without, having to boot all the way into their device's, primary operating system-even if that operating system is, Windows., At the same time, Linux is showing up on mobile Internet, devices (MIDs). This includes embedded devices such as, smart phones and PDAs, as well as netbook devicessmall laptop-type machines that feature the core, functionality of their larger counterparts in a smaller, more, energy-efficient package., The growth of cloud computing is a natural fit for Linux,, which already runs many of the Internet's web servers., Linux enables cloud services such as Amazon's A3 to, work with superior capability to deliver online applications, and information to users., Related to Linux' growth in cloud computing is the, well-known success of Linux on supercomputers, both in, the high-performance computing (HPC) and high-availability, (HA) areas, where academic research in physics and, bioengineering, and firms in the financial and energy, , Copyright @ NIMI Not to be Republished
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industries need reliable and scalable computing power to, accomplish their goals., Many of the popular Web 2.0 services on the Internet,, such as Twitter, Linked In, YouTube, and Google all rely, on Linux as their operating system. As new web services, arrive in the future, Linux will increasingly be the platform, that drives these new technologies., , The kernel of the Window operating system (which few, people outside of Microsoft are allowed to look at without, Fig 1, , Current application of Linux operating systems, Today Linux has joined the desktop market. Linux, developers concentrated on networking and services in, the beginning, and office applications have been the last, barrier to be taken down. They don't like to admit that, Microsoft is ruling this market, so plenty of alternatives, have been started over the last couple of years to make, Linux an acceptable choice as a workstation, providing an, easy user interface and MS compatible office applications, like word processors, spreadsheets, presentations and, the like. On the server side, Linux is well-known as a stable, and reliable platform, providing database and trading, services for companies like Amazon, the well-known online, bookshop, US Post Office, the German army and many, others. Especially Internet providers and Internet service, providers have grown fond of Linux as firewall, proxy- and, web server, and you will find a Linux box within reach of, every UNIX system administrator who appreciates a, comfortable management station. In post offices, they are, the nerve centres that route mail and in large search engine,, clusters are used to perform internet searches. These are, only a few of the thousands of heavy-duty jobs that Linux, is performing day-to-day across the world. It is also worth, to note that modern Linux not only runs on workstations,, mid- and high-end servers, but also on "gadgets" like PDA's,, mobiles, a shipload of embedded applications and even, on experimental wristwatches. This makes Linux the only, operating system in the world covering such a wide range, of hardware., The code, Linux is also unique from other operating systems in that, it has no single owner. Torvalds still manages the, development of the Linux kernel, but commercial and, private developers contribute other software to make the, whole Linux operating system., The kernel, All operating systems have kernels, built around the, architectural metaphor that there must be a central set of, instructions to direct device hardware, surrounded by, various modular layers of functionality. The Linux kernel is, unique and flexible because it is also modular in nature., Modularity is desirable because it allows developers to, shed parts of the kernel they don't need to use. Typically, a smaller kernel is a faster kernel, because it isn't running, processes it does not need., If a device developer wants a version of Linux to run on a, cell phone, she does not need the kernel functionality that, deals with disk drives, Ethernet devices, or big monitor, screens. She can pull out those pieces (and others), leaving, just the optimized kernel to use for the phone., , paying for the privilege) is a solidly connected piece of, code, unable to be easily broken up into pieces. It is difficult, (if not impossible) to pare down the Windows kernel to fit, on a phone., This modularity is significant to the success of Linux. The, ability to scale down (or up) to meet the needs of a specific, platform is a big advantage over other operating systems, constrained to just a few possible platforms., Modularity also effects stability and security as well. If, one piece of the kernel code happens to fail, the rest of, the kernel will not crash. Similarly, an illicit attack on one, part of the kernel (or the rest of the operating system), might hamper that part of the code, but should not, compromise the security of the whole device., The environments, The windows, menus, and dialog boxes most people think, of as part of the operating system are actually separate, layers, known as the windowing system and the desktop, environment., These layers provide the human-oriented graphical user, interface (GUI) that enables users to easily work with, applications in the operating system and third-party, applications to be installed on the operating system., In Linux, there a lot of choices for which windowing, system and desktop environment can be used,, something that Linux allows users to decide. This cannot, be done in Windows and it's difficult to do in OS X., Like the operating system and kernel, there are tools and, code libraries available that let application developers to, more readily work with these environments (e.g., gtk+ for, GNOME, Qt for KDE)., The applications, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished, , 61
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Operating systems have two kinds of applications: those, that are essential components of the operating system, itself, and those that users will install later. Closed, operating systems, like Windows and OS X, will not let, users (or developers) pick and choose the essential, component applications they can use. Windows, developers must use Microsoft's compiler, windowing, system, and so on., Linux application developers have a larger set of choices, to develop their application. This allows more flexibility to, build an application, but it does mean a developer will, need to decide which Linux components to use., The distributions, A Linux distribution is a collection of (usually open source), software on top of a Linux kernel. A distribution (or short,, distro) can bundle server software, system management, tools, documentation and many desktop applications in a, central secure software repository. A distro aims to, provide a common look and feel, secure and easy, software management and often a specific operational, purpose., Let's take a look at some popular distributions., Red hat, Red Hat is a billion dollar commercial Linux company that, puts a lot of effort in developing Linux. They have hundreds, of Linux specialists and are known for their excellent, support. They give their products (Red Hat, Enterprise Linux and Fedora) away for free. While Red, , 62, , Hat Enterprise Linux (RHEL) is well tested before release, and supported for up to seven years after release,, Fedora is a distro with faster updates but without, support., Ubuntu, Canonical started sending out free compact discs with, Ubuntu Linux in 2004 and quickly became popular for home, users (many switching from Microsoft Windows). Canonical, wants Ubuntu to be an easy to use graphical Linux desktop, without need to ever see a command line. Of course they, also want to make a profit by selling support for Ubuntu., Debian, There is no company behind Debian. Instead there are, thousands of well organised developers that elect a Debian, Project Leader every two years. Debian is seen as one of, the most stable Linux distributions. It is also the basis of, every release of Ubuntu. Debian comes in three versions:, stable, testing and unstable. Every Debian release is, named after a character in the movie Toy Story., Other, Distributions like Cent OS, Oracle Enterprise Linux and, Scientific Linux are based on Red Hat Enterprise Linux, and share many of the same principles, directories and, system administration techniques. Linux Mint, Edubuntu, and many other ubuntu named distributions are based on, Ubuntu and thus share a lot with Debian. There are, hundreds of other Linux distributions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.24 - 1.5.26, COPA - Dos & Linux Operating System, Handling commands and various editors, Objectives: At the end of this lesson you shall be able to, • know about terminal, • explain the command shell, • list out the directory layout of linux, • define the linux commands, • list out the special characters of linux OS, • explain various editors in linux OS., Starting up a terminal, , Some of the most popular shells are:, , To access the shell we will use a shell-like application,, also called a terminal emulator. There is a huge number, of good terminal applications out there, including the, default ones in GNOME or KDE, or Yakuake, Guake, rxvt, and so on. For now let's just stick with the default that, , • bash - the Bourne-Again Shell, the default shell on, most Linux systems., , • sh - the Bourne Shell, an older shell which is not so, widely used anymore., , Fig 1, , comes with your system. If you're using GNOME you can, access the terminal by going to Applications ->, Accessories -> Terminal or pressing Alt+F2 and typing, gnome-terminal in the run box that appears, followed by, Enter. If you're running KDE you can type instead, console after pressing Alt+F2., Depending on the distribution, the prompt may look something like user@host$. The first part before the ampersand is the login username, and the other one is the, hostname of the computer., Command shell, , • csh - the ‘C’ Shell, which accepts a syntax which, resembles the ‘C’ programming language., , • tcsh - an improved version of the ‘C’ Shell., • ksh - the Korn Shell, initially developed in the early, 1980’s., , • dash - Debian Almquist Shell, a shell created by the, Debian distribution., , Listing of shells available in the system, $ cat /etc/shells/, , A shell is a command interpreter which allows you to, interact with the computer. The way things work is pretty, simple: you type in commands, the shell interprets them,, performs the tasks it was asked to do, and finally it sends, the results to the standard output, which is usually the, screen., This is a list of files inside the root directory. The root, directory is the first location in the file system tree, hierarchy, and it is represented by the slash, character : /., , The above command will display the following output as, on Fig 2., In this tutorial we will focus on Bash, since it is the most, widely used and also one of the most powerful shells out, there. Bash is a modern implementation of the older, Bourne Shell (sh), developed by the GNU project, which, provides a huge amount of tools and which, together with, the Linux kernel, desktop environments like GNOME or, KDE and applications which run on top of them, comprise the whole Linux platform. On a Debian or Ubuntu, distribution, the default shell used by the system is specified in the file /etc/passwd (default being Bash)., 63, , Copyright @ NIMI Not to be Republished
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Fig 2, , How to display default shell in the system, Type the following command in the terminal, $ echo $SHELL, , And press Enter key. The default shell will be displayed, as on Fig 3., , Fig 3, , 64, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The Linux directory layout, Directory, , /bin, /boot, /dev, /etc, /home, /lib, /proc, /root, /sbin, /tmp, /usr, /usr/bin, /usr/include, /usr/lib, /usr/local, , /usr/sbin, /usr/share, /usr/src, /usr/X11R6, /var, , Description, The nameless base of the file system. All other directories, files, drives,, and devices are attached to this root. Commonly (but incorrectly), referred to as the “slash” or “/” directory. The “/” is just a directory, separator, not a directory itself., Essential command binaries (programs) are stored here (bash, ls,, mount, tar, etc.), Static files of the boot loader, Device files. In Linux, hardware devices are accessed just like other, files, and they are kept under this directory., Host-specific system configuration files., Location of users' personal home directories (e.g. /home/Susan)., Essential shared libraries and kernel modules., Process information pseudo-file system. An interface to kernel data, structures, The root (super user) home directory., Essential system binaries (fdisk, fsck, init, etc)., Temporary files. All users have permission to place temporary files here., The base directory for most shareable, read-only data (programs,, libraries, documentation, and much more)., Most user programs are kept here (cc, find, du, etc.)., Header files for compiling C programs., Libraries for most binary programs, “Locally” installed files. This directory only really matters in, environments where files are stored on the network. Locally-installed, files go in /usr/local/bin, /usr/local/lib, etc.). Also often used for, Software packages installed from source, or software not officially, shipped with the distribution., Non-vital system binaries (lpd, useradd, etc.), Architecture-independent data (icons, backgrounds, documentation,, terminfo, man pages, etc.)., Program source code. E.g. The Linux Kernel, source RPMs, etc., The X Window System, Variable data: mail and printer spools, log files, lock files, etc., , What are Linux commands?, Linux commands are executable binary files which can, be ran to perform certain tasks, like for example listing, the files in a directory running an entire graphical application. Examples of frequently used commands are ls,, cd, pwd, date or cat. With the exception of executable, files, there is also a category called shell built-ins, which, are commands provided by the shell itself (Bash in our, case). We'll deal with those later., The general form of a Linux command is:, command options(s) filename(s), Which specifies a command, followed by one or more, parameters, and optionally one or more files to apply it, on. For example:, $ echo -e 'Hello, world!\n', , Will output the text 'Hello, world!' followed by a newline, character. The -e parameter (also called argument, or, switch in this case) tells the echo command to interpret, escaped characters, like the trailing \n, which will add a, newline after the text inside the single quotes. Ignore the, leading dollar sign, it just signifies the shell prompt., A command may or may not have arguments. An argument can be an option or a filename., Special characters in linux operating system, it is important to know that there are many symbols and, characters that the shell interprets in special ways. This, means that certain typed characters: a) cannot be used, in certain situations, b) may be used to perform special, operations, or, c) must be "escaped" if you want to use, them in a normal way., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 65
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Character, , \, , Escape character. If you want to reference a special character, you must, “escape” it with a backslash first., Example: touch /tmp/filename\*, , /, , Directory separator, used to separate a string of directory names., Example: /usr/src/linux, , ., , Current directory. Can also “hide” files when it is the first character in a, filename., , .., , Parent directory, , ~, , User's home directory, , *, , Represents 0 or more characters in a filename, or by itself, all files in a, directory., Example: pic*2002 can represent the files pic2002, picJanuary2002,, picFeb292002, etc., , ?, , Represents a single character in a filename., Example: hello?.txt can represent hello1.txt, helloz.txt, but not, hello22.txt, , [], , Can be used to represent a range of values, e.g. [0-9], [A-Z], etc., Example: hello[0-2].txt represents the names hello0.txt,, hello1.txt, and hello2.txt, , |, , “Pipe”. Redirect the output of one command into another command., Example: ls | more, , >, , Redirect output of a command into a new file. If the file already exists,, over-write it., Example: ls > myfiles.txt, , >>, , 66, , Description, , Redirect the output of a command onto the end of an existing file., Example: echo .Mary 555-1234. >> phonenumbers.txt, , <, , Redirect a file as input to a program., Example: more < phonenumbers.txt, , ;, , Command separator. Allows you to execute multiple commands on a single, line., Example: cd /var/log ; less messages, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The cd command, The cd command is used to change the current directory, (i.e., the directory in which the user is currently working), in Linux and other Unix-like operating systems. It is similar, to the CD and CHDIR commands in MS-DOS., cd's syntax is, cd [option] [directory], The items in square brackets are optional. When used, without specifying any directory name, cd returns the user, to the previous current directory. This provides a convenient, means of toggling between two directories., When a directory name is provided, cd changes the current, directory to it. The name can be expressed as an absolute, pathname (i.e., location relative to theroot directory) or as, a local pathname (i.e., location relative to the current, directory). It is usually more convenient to use a local, pathname when changing to a subdirectory of the current, directory., As an example, the following would change the current, directory, regardless of where it is on the system (because, it is an absolute path), to the root directory (which is, represented by a forward slash):, cd /, Likewise, the following would change the current directory,, regardless of its location, to the /usr/sbin directory (which, contains non-vital system utilities that are used by the, system administrator):, cd /usr/sbin, If a user currently in the directory /usr/local/share/man/, desired to change to the directory /usr/local/share/man/, man2, which is a subdirectory of the current directory, it, would be possible to change by using the absolute, pathname, i.e.,, cd /usr/local/share/man/man2, However, it would clearly be much less tedious to use the, relative pathname, i.e.,, cd man2, On Unix-like operating systems the current directory is, represented by a singledot and its parent directory (i.e.,, the directory that contains it) is represented by two, consecutive dots. Thus, it is possible (and often convenient), to change to the parent of the current directory by using, the following:, cd .., Another convenient feature of cd is the ability for any user, to return directly to its home directory by merely using a, tilde as the argument. A home directory, also called a, login directory, is the directory on a Unix-like operating, system that serves as the repository for a user's personal, files, directories and programs. It is also the directory that, a user is first in after logging into the system. A tilde is a, short, wavy, horizontal line character that represents the, , home directory of the current user. That is, any user can, return immediately to its home directory by typing the, following and then pressing the Enter key:, cd ~, This is easier than typing the full name of the user's home, directory, for instance, /home/josephine in the case of a, user named josephine. (And it is just one of the numerous, shortcuts that help make the command line on Unix-like, operating systems so easy to use.), When followed by a space and then a hyphen, cd both, returns the user to the previous current directory and, reports on a new line the absolute pathname of that, directory. This can further enhance the already convenient, toggling capability of cd. Toggling is particularly convenient, when at least one of the two directories has a long absolute, pathname, such as /usr/local/share/man/man2., cd has only two options, and neither of them are, commonly used. The -P option instructs cd to use the, physical directory structure instead of following symbolic, links. The -L option forces symbolic links to be followed., The pwd command, The pwd command reports the full path to the current, directory., The current directory is the directory in which a user is, currently operating while using a command line interface., A command line interface is an all-text display mode and, it is provided via a console (i.e., a display mode in which, the entire screen is text only) or via a terminal window, (i.e., a text-only window in a GUI)., The full path, also called an absolute path, to a directory, or file is the complete hierarchy of directories from the, root directory to and including that directory or file. The, root directory, which is designated by a forward slash (/),, is the base directory on the filesystem (i.e., hierarchy of, directories), and it contains all other directories,, subdirectories and files on the system. Thus, the full path, for any directory or file always begins with a forward slash., pwd is one of the most basic commands in Linux and, other Unix-like operating systems, along with ls, which is, used to list the contents of the current directory, andcd,, which is used to change the current directory., pwd's syntax is, pwd [option], Unlike most commands, pwd is almost always used just, by itself, i.e.,, Pwd, That is, it is rarely used with its options and never used, with arguments (i.e., file names or other information, provided as inputs). Anything that is typed on the same, line after pwd, with the exception of an option, is ignored,, and no error messages are returned., As an example, if a user with the username janis is in its, home directory, then the above command would typically, return /home/janis/ (because, by default, all home, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 67
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directories are located in the directory /home). Likewise,, if a user were currently working in directory /usr/share/, config (which contains a number of programconfiguration, files), then the same command would return /usr/share/, config., pwd is useful for confirming that the current directory has, actually been changed to what the user intended after, using cd. For example, after issuing the cd command to, change the current directory from /home/janis to /usr/share/, config, pwd could be used for confirmation; that is, the, following sequence of commands would be issued:, cd /usr/share/config/, pwd, The standard version of pwd has a mere two options, both, of which are employed only infrequently. The --help option, is used as follows:, pwd --help, This option displays information about pwd, of which there, is very little because it is such a simple command (i.e., it, only has two options and accepts no arguments)., The other option is --version, which displays the version, number, i.e.,, pwd --version, Although it is often thought of as standing for present, working directory, pwd is actually an acronym for print, working directory. The word print is traditional, UNIXterminology for write or display, and it originated when, computer output was typically printed on paper by default, because CRT (cathode ray tube) display monitors were, not yet widely available., The echo command, echo is a built-in command in the bash and C shells that, writes its arguments to standard output., A shell is a program that provides the command line (i.e.,, the all-text display user interface) on Linux and other Unixlike operating systems. It also executes (i.e., runs), commands that are typed into it and displays the results., bash is the default shell on Linux., A command is an instruction telling a computer to do, something. An argument is input data for a command., Standard output is the display screen by default, but it, can be redirected to a file, printer, etc., The syntax for echo is, $ echo $USER, $ echo "Hello world", The items in square brackets are optional. A string is any, finite sequence of characters (i.e., letters, numerals,, symbols and punctuation marks)., When used without any options or strings, echo returns a, blank line on the display screen followed by the command, prompt on the subsequent line. This is because pressing, the ENTER key is a signal to the system to start a new, 68, , line, and thus echo repeats this signal., When one or more strings are provided as arguments,, echo by default repeats those stings on the screen. Thus,, for example, typing in the following and pressing the ENTER, key would cause echo to repeat the phrase This is a pen., on the screen:, echo This is a pen., It is not necessary to surround the strings with quotes, as, it does not affect what is written on the screen. If quotes, (either single or double) are used, they are not repeated, on the screen., Fortunately, echo can do more than merely repeat verbatim, what follows it. That is, it can also show the value of a, particular variable if the name of the variable is preceded, directly (i.e., with no intervening spaces) by the dollar, character ($), which tells the shell to substitute the value, of the variable for its name., For example, a variable named x can be created and its, value set to 5 with the following command:, x=5, The value of x can subsequently be recalled by the following:, echo The number is $x., Echo is particularly useful for showing the values of, environmental variables, which tell the shell how to behave, as a user works at the command line or in scripts(short, programs)., For example, to see the value of HOME, the environmental, value that shows the current user's home directory, the, following would be used:, echo $HOME, Likewise, echo can be used to show a user's PATH, environmental variable, which contains a colon-separated, list of the directories that the system searches to find the, executable program corresponding to a command issued, by the user:, echo $PATH, echo, by default, follows any output with a newline, character. This is a non-printing (i.e., invisible) character, that represents the end of one line of text and the start of, the next. It is represented by \n in Unix-like operating, systems. The result is that the subsequent command, prompt begins on a new line rather than on the same line, as the output returned by echo., The -e option is used to enable echo's interpretation of, additional instances of the newline character as well as, the interpretation of other special characters, such as a, horizontal tab, which is represented by \t. Thus, for, example, the following would produce a formatted output:, echo -e "\n Projects: \n\n\tplan \n\tcode \n\ttest\n", (The above command should be written on a single line,, although it may render as two lines on smaller display, screens.) The -n option can be used to stop echo from, adding the newline to output., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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By making use of output redirection, echo provides a very, simple way of creating a new file that contains text. This, is accomplished by typing echo followed by the desired, text, the output redirection operator (which is a rightward, pointing angle bracket) and finally the name of the new, file. The file can likewise be formatted by using special, characters. Thus, for example, the formatted output from, the above example could be used to create a new file, called project1:, , Date command, , echo -e "\n Project1: \n\n\tplan \n\twrite \n\ttest\n" >, project1, , 01:13:14, , The contents of the new file, including any formatting, can, be verified by using a command such as cat or less, i.e.,, , Display current time and date., $ date, Fri Jul 6 01:07:09 IST 2012, If you are interested only in time, you can use 'date +%T', (in hh:mm:ss):, $ date +%T, tty command, Displays current terminal., $ tty, , less project1, echo can likewise be a convenient way of appending text, to the end of a file by using it together with the the append, operator, which is represented by two consecutive rightward, pointing angle brackets. However, there is always the risk, of accidentally using a single bracket instead of two,, thereby overwriting all of the contents of the file, and thus,, this feature is best reserved for use in scripts., echo can also be used with pattern matching, such as the, wildcard character, which is represented by the star, character. For example, the following would return the, phrase The gif files are followed by the names of all the .gif, image files in the current directory:, echo -e The gif files are *.gif, , /dev/pts/0, whoami command, This command reveals the current logged in user., $ whoami, raghu, id command, This command prints user and groups (UID and GID) of, current user., $ id, uid=1000(raghu) gid=1000(raghu), groups = 1000 (raghu), 4(adm), 20(dialout), 24(cdrom),, 46(plugdev), 112(lpadmin), 120(admin),122(sambashare), , The cal command, Displays calendar of current month., , By default information about current user is displayed. If, another username is provided as an argument, information, about that user will be printed:, , $ cal, July 2012, , $ id root, , Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , Clear command, , 15, , 16, , 17, , 18, , 19, , 20, , 21, , This command clears the screen., , 22, , 23, , 24, , 25, , 26, , 27, , 28, , Getting help command, , 29, , 30, , 31, , 'cal ' will display calendar for specified month and year., $ cal 08 1991, August 1991, Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , uid=0(root) gid=0(root) groups=0(root), , For all its advantages, a big disadvantage of command, line is that there are a lot of commands and even more are, their options and usage. But nobody can remember all, commands. There are some smarter ways of using, command line. Linux provides us with several such, resources discussed here:, --help option, With almost every command, '--help' option shows usage, summary for that command., , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , 15, , 16, , 17, , $ date --help, , 18, , 19, , 20, , 21, , 22, , 23, , 24, , Usage: date [OPTION]... [+FORMAT], , 25, , 26, , 27, , 28, , 29, , 30, , 31, , or: date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]], Display the current time in the given FORMAT, or set the, system date., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 69
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The whatis command, , $ info date, , The whatis command provides very brief descriptions of, command line programs (i.e., all-text mode programs) and, other topics related to Linux and other Unix-like operating, systems., It accomplishes this by searching the short descriptions, in the whatis database for each keyword provided to it as, an argument (i.e., input data). This database contains just, the title, section number and description from the NAME, section of each page in the man manual that is built into, most Unix-like systems., The syntax for whatis is:, whatis keyword(s), For example, the following provides a single line summary, of the headcommand (which by default displays the first, ten lines of each file that is provided to it as an argument):, whatis head, whatis can be used to simultaneously search for information, about multiple topics. For example, the following would, provide information about both head and tail (which by, default reads the final ten lines of files):, whatis head tail, The output of whatis is limited by the fact that it provides, only a single line for each keyword found in the database;, thus it supplies incomplete information about even, moderately complex commands. For example, the, following use of whatis to obtain information about the cat, command generates the output "concatenate files and print, on the standard output":, whatis cat, However, this omits some important information about cat,, particularly the facts that it is very convenient to use for, reading files and that it is also used to create and write to, files., whatis is similar to the apropos command. However,, apropos is more powerful in that its arguments are not, limited to complete words but can also be strings (i.e.,, any finite sequences of characters) which comprise parts, of words. Both commands are unusual in that they have, no options., The man command (which is used to read the built-in, manual pages), when used with its -f option, produces the, same output as whatis. Thus, for example,, man -f cat, is equivalent to, whatis cat, Info pages, , Word processors in the Linux environment, Text editors are used by many different types of people., Casual users, writers, programmers, and system, administrators will all use a text editor at one time or another, in Linux., Use of text editor, A text editor is just like a word processor without a lot of, features. All operating systems come with a basic text, editor. Linux comes with several. The main use of a text, editor is for writing something in plain text with no formatting, so that another program can read it. Based on the, information it gets from that file, the program will run one, way or another., vi Editor, "vi" (pronounced "vee eye") is a text editor with a, deceptively simple appearance that belies its great power, and efficiency. New users soon realize that there is far, more to this little program than meets the eye., vi, or one of its clones, is found in almost every version of, Linux and Unix, and, in fact, it is the only editor that is, available in virtually every Unix installation., History of vi, The vi editor was developed starting around 1976 by Bill, Joy, who was then a graduate student at the University of, California at Berkeley. Joy later went on to help found Sun, Microsystems and became its Chief Scientist., "ed" was the original Unix text editor. Like other early text, editors, it was line oriented and used from dumb printing, terminals. Joy first developed "ex" as an improved line, editor that supported a superset of ed commands. He then, developed vi as a "visual interface" to ex. That is, it allows, text to be viewed on a full screen rather than only one line, at a time. vi takes its name from this fact., vi remains very popular today in spite of the development, and widespread availability of GUI (graphical user interface), mode text editors which are far more intuitive and much, easier for beginners to use than text-mode text editors, such as vi. GUI-mode text editors include gedit and Emacs,, both, of, which, have, become, very, common on Linux and other Unixes today., Features of vi, , • It is present in almost every Linux Unix system, even, the most minimal., , • It is very small. In fact, some versions have a total, , code size of less than 100KB. This makes it easy to, include vi on even the tiniest versions of Linux, such as, those in embedded systems and those that run from a, single floppy disk., , Info documents are sometimes more elaborated than man, pages. But for some commands, info pages are just the, • It is typist-friendly, at least once you get used to it. For, same as man pages. These are like web pages. Internal, example, the commands are very short, usually just a, links are present within the info pages. These links are, few keystrokes. And because vi does not use the, called nodes. info pages can be navigated from one page, mouse, there is never any need to remove one's hands, to another through these nodes., 70, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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from the keyboard. This can speed up editing, substantially., , changes, hit ESC, type :q! and then press ENTER. This, is sometimes referred to as a "forced quit.", , • It is very powerful, as just a few very short commands, , vi works with a buffer (a block of memory in the RAM, chips). When you open an existing file, vi copies that file, from the hard disk (or floppy, CDROM, etc.) to a buffer. All, changes that you make to a file are initially made only to, the copy in the buffer, and they are only made to the file, itself when you "save" your changes. "Saving" a file means, writing (i.e., transferring) the contents of the buffer to the, hard disk (or floppy disk)., , can make sweeping changes to large documents. In, fact, vi is more powerful than most of its users realize,, and few of them know more than just fraction of all the, commands., , Opening and closing file, vi can be used both when your system is in text mode, (the entire screen is devoted to text and there are no, images) and when your system is in GUI mode (the screen, contains windows, images and menus). When it is in GUI, mode (usually KDE or Gnome), vi runs in a terminal window., A terminal window is a text-only window, and it can usually, be opened by clicking on an icon (small image) of a, computer screen., (In the case of Red Hat Linux, the terminal window can be, opened by clicking on the icon of a red hat in the lower left, hand corner of the screen, opening the System Tools menu, and then selecting Terminal from that menu. It can be, convenient to add the icon for the terminal window to the, launcher panel along the bottom of the screen, if it is not, already there.), There are at least two ways to use vi to simultaneously, create and open a new file. One is by just typing vi at the, command line, like this:, vi, This creates an empty file that will not have a name until, you save its contents to disk (i.e., transfer the text you, typed into it to your hard disk, floppy disk, etc. for long, term storage)., A second way to open a new file is by typing vi followed by, the name of the file to be created, for example:, vi apple, This creates a new file named "apple" in the current, directory (the directory or folder which is currently open, on your all-text screen or your terminal window)., If you want, it could create the same file with an extension, such as ".txt" added to the end of the file name. In Linux, this is merely a matter of convenience (or habit), and it, generally makes no real difference for the file because it, remains a plain text file in either case. For example:, vi apple.txt, To close a file to which no changes have been made, hit, ESC (the Esc key, which is located in the upper left hand, corner of the keyboard), then type :q (a colon followed by, a lower case "q") and finally press ENTER. (The term "hit", is used here instead of "press" to emphasize that it is not, necessary to keep the ESC key held down but just to, press it momentarily.), To close a file to which changes have been made (such as, text having been added or removed) without saving the, , Likewise when you open a new file. All text you enter (and, subsequent edits you make to it) exists only in the buffer, until you save the file to disk., To save the changes that have been made to a file, hit, ESC, type :qw and then press ENTER. The "w" stands for, "write." An alternative, and perhaps easier, way to save a, file and quit at the same time is to hit ESC and then type, ZZ (two capital Z's in succession)., After you have created a new text file and closed it, you, might want to confirm that nothing went wrong and that, the file actually exists. Probably the simplest way to do, this is to use the standard Unix ls command, which, displays a list of all of the files in the current directory., Entering text, vi has two basic modes of operation: command mode and, text insert mode. How to switch back and forth, between them is probably the most confusing thing about, vi for beginners. But it is actually very simple, and once, you get used to it you might also find it quite efficient., Command mode is the default mode when a file (existing, or new) is opened. (This is the opposite of most text and, word processors and therefore may seem counter-intuitive.), Because every file opens initially in command mode, you, can not immediately begin typing text. That is, everything, that is typed on the keyboard is interpreted by vi to be a, command., Examples of the many types of commands can perform, on a file while in command modes are:-, , • Switching to text insert mode., • Moving the cursor around the file., • Deleting characters or lines., • Transposing characters., • Changing case., • Appending the contents of the file to another (closed), file., , • Setting vi options., • Saving the file to disk., • Closing the file and quitting vi., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 71
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The other mode, text insert mode, is also referred to as, simply "insert mode" or "input mode." It is used for entering, text into the buffer memory (and simultaneously onto the, screen). In this mode everything that is typed on the, keyboard is added to the text and does not become a, command (although you can perform some command, operations in text mode with vi clones)., , There will be times when it need to place a character to, the right of the character under the cursor. This is, particularly useful when the cursor is over the last character, in a line and you want to append the line. To do this,, simply use the a (lower case "a," which stands for "append"), command instead of the i command to switch from, command mode into insert mode., , The most common way to switch from command mode to, the input mode is to use the i (which stands for "insert" or, "input") command. This is accomplished by simply typing, the letter i while in command mode. Now you are ready to, start typing text., , After it have saved a file that have created or modified, using vi, might want to verify that its contents are really, what you had intended. One way to do this is to use cat,, the Unix concatenation utility. (No, this has no relationship, to the popular domesticated animal whose name has the, same spelling). For example, type:, , Unlike word processors and even most word editors, there, is no automatic word wrap in the traditional version of vi, (although you will notice it in some clones). New lines are, started by pressing ENTER., When finished typing text or need to perform some other, operation such as moving to a different position in the text, or deleting some of it, hit ESC in order to return to the, command mode., Once you have typed some text, you can use the four, basic commands for moving the cursor around the text., These commands enable you to go to any desired location, in order to modify the text, including making insertions, and deletions. The four basic cursor positioning commands, are:, h move cursor one character to left, j move cursor one line down, k move cursor one line up, l move cursor one character to right, Each of these commands can be either used by itself or, modified by typing an integer in front of it to indicate the, number of characters or lines to move. For example, typing, (in command mode, of course), 3j - will move the cursor down three lines. Or typing 2h will, move it two characters to the left., These commands can be repeated by holding the key, down. If attempting an impossible movement, such as, pressing k when the cursor is on the top line, the screen, might flash or a beeping sound might be made (depending, on how your computer is set up)., The cursor can be moved directly to any desired line by, using the G command preceded by the line number. For, example, typing, 5G - moves the cursor to the fifth line from the top of the, text. Just typing G without any number moves the cursor, to the final line of text., When you switch from command mode to input mode, with the i command and then start typing text, each, character you type is placed to the left of the character, covered by the cursor. This causes the character covered, by the cursor as well as everything to its right to be shifted, to the right., 72, , cat /home/john/fruit/lemon, Editing Text, vi offers a rich assortment of commands for editing text., Among the most basic are those used for deleting or, erasing., The x (lower case "x") command deletes the character, immediately under (i,e., covered by) the cursor. To delete, any desired character, just switch to the command mode, (if you are not already there) and then use an appropriate, combination of the h, j, k and l commands (of course, one, at a time) to move the cursor to that character. Then type, x and the character is deleted., By pressing x continuously instead of just hitting it once,, the cursor continuously moves to the right and each, character under it is successively deleted., The X (upper case "X") command is similar except that it, deletes the character to the left of the cursor rather than, the character under it., There are several additional commands for deleting text., The D (upper case "D") command removes the text on the, current line from the character under the cursor to the end, of the line., The d (lower case "d") command is very flexible because, it can be modified to delete any number of characters,, words or lines. Typing d by itself will not do anything, but, typing dw causes the character the cursor is resting on, and the remaining characters to the right of it in the same, word to be deleted. (The "w" stands for "word."), Typing 2dw causes the character under the cursor, the, remaining characters to the right of it in the same word, and all of the characters in the next word to be deleted., For example, typing 2dw with the cursor on the "a" of the, string "pineapple plantation" causes the string "apple, plantation" to be deleted., As another example, typing 3dw with the cursor on the "j", of the string "the bluejay flew south" causes the string, "jay flew south" to be deleted. That is, "jay" and two words, to the right of it are deleted., Deleting an entire line can be accomplished with the dd, command. This command can also be used to delete, multiple lines by preceding it with an integer representing, the number of lines to be removed. For example, typing, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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2dd will delete two consecutive lines beginning with the, current line., , lines can be transposed with the ddp command by placing, the cursor on the upper line and typing ddp., , With some terminals, deletion of a line causes it to be, replaced on the screen with an "@" character. This, character merely represents an empty line and is not, inserted into the text. Its purpose is to relieve the processor, from having to redraw the screen (i.e., change the whole, screen). This character can be removed if desired by typing, r (or l on some terminals) while holding down the CTRL, key., , It is also a simple matter to change the case of a letter., When the cursor is over the desired letter, hit the "~" (tilde), key. This will change a capital letter to a small letter and, visa versa., , The change command c (lower case "c") differs from the, delete command in that it not only deletes a section of, text but also activates insert mode to allow you to type in, replacement text. After you have completed typing in the, replacement text, be sure to press ESC to return to the, command mode., As is the case with d, the c command is not used by itself, but is only used in combination with another letter after it, and an optional integer before it., For example, the command cw (which stands for "change, word") deletes the characters in the current word under, and to the right of the cursor and then switches vi to the, insert mode so that you can enter text to replace the deleted, characters. The number of new characters typed in can, be the same as, fewer or more than the number deleted., The amount of text to be changed can be increased by, preceding the command with a number. For instance, typing, 2cw will additionally remove the next word for replacement, with whatever is typed in. The space between the words is, not preserved., The d and c commands can also be modified by other, characters in addition to "w." For example they can be, used with "b," which stands for "back." Thus, typing3bd, will delete the characters to the left of the cursor in the, current word together with the two words to the left of the, current word., The cc command erases the current line, leaving it blank, and awaiting replacement text. Preceding this command, with an integer will delete that number of lines, beginning, with the current line. For example, typing 5cc will allow, you to change five consecutive lines starting with the current, line., Another change command, R, differs from the c commands, in that it does not initially delete anything. Rather, it, activates insert mode and lets you replace the characters, under the cursor one at a time with characters that you, type in., vi supports several types of transposition. Transposing the, order of two adjacent characters is easy with the xp, command. Just place the cursor on the left-most of the, two characters, type x to erase the left character and then, type p for the deleted character to be put to the right of the, cursor., Two adjacent words can be transposed with the deep, command. To use it, position the cursor in the space just, to the left of the word on the left and type deep. Two adjacent, , The J (upper case "J") command is used to join the next, line to the current line. The opposite operation, splitting a, line, is accomplished in insert mode by merely positioning, the cursor over what will be the first character of the new, line and then hitting ENTER., vi also has an undo capability. The u (lower case "u"), command is used to reverse the effects of an already issued, command that has changed the buffer, but which is not, yet written to disk. U (upper case "U") undoes all of the, changes that have been made to the current line during, your current visit to it, Searching Text, vi also has powerful search and replace capabilities. To, search the text of an open file for a specific string, (combination of characters or words), in the command, mode type a colon (:), "s," forward slash (/) and the search, string itself. What you type will appear on the bottom line, of the display screen. Finally, press ENTER, and the, matching area of the text will be highlighted, if it exists. If, the matching string is on an area of text that is not currently, displayed on the screen, the text will scroll to show that, area., The formal syntax for searching is:, :s/string, For example, suppose you want to search some text for, the string "cherry." Type the following and press ENTER:, :s/cherry, The first match for "cherry" in your text will then be, highlighted. To see if there are additional occurrences of, the same string in the text, type n, and the highlight will, switch to the next match, if one exists., The syntax for replacing one string with another string in, the current line is, :s/pattern/replace/, Here "pattern" represents the old string and "replace", represents the new string. For example, to replace each, occurrence of the word "lemon" in a line with "orange,", type:, :s/lemon/orange/, The syntax for replacing every occurrence of a string in, the entire text is similar. The only difference is the addition, of a "%" in front of the "s":, :%s/pattern/replace/, Thus repeating the previous example for the entire text, instead of just for a single line would be:, :%s/lemon/orange/, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 73
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Working with multiple files, It is easy to insert text into an open file from another file., All that is necessary is to move the cursor to the location, where you want the text inserted, then type, :r filename, where "filename" is the name of the file to insert., For example, if you want to copy the contents of the file, "peach" into the file "fruit," you would first position the, cursor to the desired line in "fruit" and then type, :r peach, Notice that this operation causes no change to the file, "peach.", , vi +3 apple, Use of the + command without any modifying number, opens a file with the cursor positioned on the last line of, text. This can save some keystrokes when you want to, open a file just to append data to the end of it. For example:, vi + apple, You have already learned several commands for switching, from command mode to insert mode, including i for, inserting to the left of the cursor position, a for inserting to, the right of the cursor position and the c commands for, changing text. A more complete list is as follows:, a, , appends after current cursor position., , A, , appends at end of current line., , c, , starts a change option., , C, , starts a change option from current position, to end of current line., , i, , inserts to the left of the cursor position., , I, , inserts at start of line., , o, , cursor moves to new, blank line below its, current position., , This allows you to edit "apple" first. After saving "apple,", typing :n calls up "pear" for editing., , O, , cursor moves to new, blank line above its, current position., , If you want to simultaneously open all files in the current, directory, just type vi * (vi + space + asterisk)., , R, , replaces characters one at a time., , Additional operations, , A simple way to obtain basic information about any file, that is currently open, including name, size and the current, line number, is to hold down CTRL and type g. This data, appears on the bottom line of the display., , You can also append text from the currently open file to, any other file. This is accomplished using the :w (colon +, "w") command followed without a space by >>. For, example, to append the contents of a currently open file, named "pear" to the file named "apple," type, :w>> apple, At times it can be convenient to open multiple files, simultaneously. This is efficiently accomplished by just, listing all of the files to be opened after the vi command., For example, to simultaneously open files about three kinds, of fruit, type:, vi apple pear orange, , As you have learned, creating and opening files in vi can, be a very simple matter. However, many combinations of, options are available that can add much power and, flexibility for these tasks, as can be seen by looking at, the full syntax for opening files:, vi [flags] [cmd] [filename], The square brackets ([ ]) around each section of arguments, (modifiers) of the command indicates that they are optional., (That is, a file can be opened by just typingvi alone or by, typing it with any combination of the three arguments. For, instance, the example of vi dog contains only the, mandatory vi and the optional third argument, which is the, name of the file to open.), , Summary of commands, The following list contains the basic commands presented, in the first eight pages of this tutorial along with occasional, examples of usage (shown in parenthesis). They are, presented in roughly the same order in which they appear, in the tutorial. (All commands that begin with a colon are, followed by ENTER.), , As only one of many possible examples of adding options, for opening files, an existing file can be opened with the, cursor appearing on any desired line instead of just on the, first line. (One situation in which this can be particularly, useful is if your file is part of a program which you are, writing and the compiler reports an error on a specific line, in that file.) This is accomplished by adding the + (plus, sign) command followed the desired line number. For, example, to open the file "apple" with the cursor located, on the third line, type:, 74, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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vi, vi *, , typed at the command line to open one or more files in the same directory, (vi tomato.txt opens a file named "tomato.txt" in the current directory), (vi parsley sage rosemary opens the three files "parsley," "sage" and, "rosemary" in the current directory), typed at the command line to open every file in the current directory, , :q, , closes (quits) a file to which no changes have been made, , :q!, , quits without saving any changes, , :w, , writes (i.e., saves) the current file to disk, , :wq, ZZ, i, h, , writes the buffer contents to disk (i.e., saves changes) and quits, same as :wq, activates text insert mode, inserting text immediately under the current, position of the cursor., moves the cursor one character to the left, (2h moves the cursor two characters to the left), , j, , moves the cursor one line down, (3j moves the cursor three lines down), , k, , moves the cursor one line up, , l, , moves the cursor one character to the right, , G, , moves the cursor to the desired line; moves the cursor to the last line of text, if not preceded by a modifying integer, (5G moves the cursor to the fifth line), , a, , switches to insert mode and allows insertion of text immediately to the right, of the cursor., , x, , deletes the character immediately under the cursor, (xxx deletes the character immediately under cursor and then deletes the, two characters to its right), , X, , deletes a single character to the left of cursor, , D, , removes the text on the current line from the character under the cursor to, the end of the line, , dw, , deletes the character immediately under the cursor and the remaining, characters to the right of it in the same word, (2dw deletes the character immediately under the cursor, the remaining, characters to the right of it in same word and all of the next word), , dd, , deletes the entire line containing the cursor, and the cursor then moves to, the next line, (2dd deletes two consecutive lines beginning with the current line), , cw, , deletes the character under the cursor and to its right in the same word and, allows new characters to be typed in to replace them, (2cw deletes the character under the cursor and to its right in the same, word and in the next word, and then allows replacement characters to be, typed in), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 75
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cc, , erases the current line and allows replacement text to be typed in, (2cc erases the current line and the next line and allows replacement text to, be typed in for both lines), , cb, , deletes the characters to the left of the cursor in the current word and allows, replacement characters to be typed in, (3cb deletes the characters to the left of the cursor in the current word, together with the two words to its left and then allows replacement text to be, typed in), , R, , activates text input mode allowing text under and to the right of the cursor to, be overwritten one character at a time, , xp, , transposes two adjacent characters, , deep, ddp, , transposes two adjacent lines, , ~, , changes case of the character under the cursor, , J, , joins the current line with the next line, , u, , reverses the effects of the most recent command that has changed the buffer, , U, , undoes all changes made to the current line during the current visit to it, , :s/, n, :s/ / /, , :%s/, //, , 76, , transposes two adjacent words, , searches the text for the first instance of a designated string, (:s/cucumber searches the text for the first instance of the string, "cucumber"), searches the text for the next instance of a designated string, replaces the first instance of a designated string, (:s/cucumber/radish/ replaces the first instance of the string "cucumber" with, the string "radish"), replaces every instance of a designated string, (:%s/cucumber/radish/ replaces every instance of the string "cucumber" with, the string "radish"), , :r, , inserts text into the currently open file from another file, (:r lettuce.txt inserts text into the currently open file from the file named, "lettuce.txt"), , :w>>, , appends the text from the currently open file into another file, (:w>> cabbage appends the text from the currently open file into the file, named "cabbage"), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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pico editor, , offered as the default in subsequent searches., , pico is a simple text editor in the style of the pine, composer., , Blocks of text can be moved, copied or deleted with, creative use of the command for mark (Ctrl-^), delete, (Ctrl-k) and undelete (Ctrl-u). The delete command will, remove text between the "mark" and the current cursor, position, and place it in the "cut" buffer. The undelete, command effects a "paste" at the current cursor, position., , Syntax, pico [ options ] [ file ], Description, pico is a simple, display-oriented text editor based on the, pine message composer. As with pine, commands are, displayed at the bottom of the screen, and context-sensitive, help is provided. As characters are typed they are, immediately inserted into the text., Editing commands are entered using control-key, combinations. As a work-around for communications, programs that swallow certain control characters, you can, emulate a control key by pressing ESCAPE twice, followed, by the desired control character. For example, "ESC ESC, c" would be equivalent to entering a ctrl-c. The editor has, five basic features: paragraph justification, searching, block, cut/paste, a spelling checker, and a file browser., Paragraph justification (or filling) takes place in the, paragraph that contains the cursor, or, if the cursor is, between lines, in the paragraph immediately below., Paragraphs aredelimited by blank lines, or by lines, beginning with a space or tab. Unjustification can be done, immediately after justification using the control-U key, combination., String searches are not sensitive to case. A search, begins at the current cursor position and wraps around, the end of the text. The most recent search string is, To, , The spell checker examines all words in the text. It then, offers each misspelled word for correction while highlighting, it in the text. Spell checking can be cancelled at any time., Alternatively, pico will substitute for the default spell, checking routine a routine defined by the SPELL, environment variable. The replacement routine should read, standard input and write standard output., The file browser is offered as an option in the "Read File", and "Write Out" command prompts. It is intended to help, in searching for specific files and navigating directory, hierarchies. Filenames with sizes and names of directories, in the current working directory are presented for selection., The current working directory is displayed on the top line, of the display while the list of available, commands takes up the bottom two. Several basic file, manipulation functions are supported: file renaming,, copying, and deletion., Movement commands:, Depending on your system, the arrow keys or the, backspace key may not work. Instead, you can use these, commands to perform the same tasks., , Hold down Ctrl key and press, , Delete a character, , backspace, , Instead of, backspace, , Move up a line, , p, , up arrow, , Move down a line, , n, , down arrow, , Move left one space, , b, , left arrow, , Move right one space, , f, , right arrow, , Move to the end of line, , e, , end, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 77
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Some pico editor options, , ^K Cut text, , ^C Cancel allows you to stop a process at any time. If, you make a mistake, just hold down the Ctrl key and, press c., , Cut a line of text. This option allows you to cut a full line, of text. By using the uncut command and your arrow, keys, you can then paste the cut text at another location, in your document. To cut specific text in a line or to cut, several lines of text, first select the text (see Selecting, Text on the next page)., , ^G get help, Get clear and concise assistance from the Pico help, in, case something unexpected happens or you need, additional information about a command., ^X Exit, , Selecting text, To select text for cutting and pasting use the following, steps:, , Exit Pico at anytime. If made changes to a file or worked, on a new file, but you havent saved the changes, you see, this message:, , Move the cursor to the beginning of the text to select, , Save modified buffer (ANSWERING "No" WILL DESTROY, CHANGES) (y/n)?, , Use the right arrow key or hold down Ctrl and press f to, highlight text, , Answering no (press n) will close Pico and bring you back, to the prompt without saving your file., , When you have highlighted the appropriate text, hold down, the Ctrl key and press k to cut it., , Answering yes (press y) will allow you to save the file, you've been working on (see Write Out section below for, details)., , Paste the text you cut, anywhere in your document, using, UnCut Text, , ^O WriteOut, Save the file without hassles or worries. Fill in the name, of the file beside the File Name to write: prompt. If the file, already has a name, then press enter., ^T To Files option lets to save the text over a file that, exists in the directory. By choosing the To Files option,, Pico takes you to a directory Browser., ^R Read File, Insert text from another file into your current text file. This, option allows you to search through your directories for a, file that you would like to add to your text. This option is, especially handy if you've saved a document and would, like to add its content to the new file you're working on., Text from the file you select is placed on the line directly, above your cursor., At the Insert file : prompt you may either type a file name, or use the Browser options., ^T To Files option lets you import a text file directly into, the file you're currently typing. By choosing the To Files, option, Pico takes you to a directory Browser., ^Y Prev Pg, Move quickly to the previous page. Although you could, just as easily press the up arrow key several times, this, command quickly jumps your cursor up one page., ^V Next Pg, Move quickly to the next page. Although you could just, as easily press the down arrow key several times, this, command quickly jumps your cursor down one page., 78, , Hold down the Ctrl key and press ^, , ^U UnCut Text, Paste text that previously cut. if use this option to undo, an accidental cut of text or place cut text at another location, in the document. The text you cut is pasted on the line, directly above the cursor., ^C Cur Pos, Indicate the current position of the cursor, relative to the, entire document. This is a helpful option if you'd like to, check exactly where in the document. The status line, indicates the following items:, [line 8 of 18 (44%), character 109 of 254 (42%)], ^J Justify, Even out lines of text. This command is handy when, accidentally type extra spaces between words or press, the key before reaching the end of a line. The option, evens the length of text lines automatically., ^U UnJustify, UnJustify lines of text. For the messy line look you can, always select the UnJustify option., ^W Where is, Find a particular string of text quickly. This option allows, you to do a word search in your text. This option is, especially handy for longer documents. If the word you, designated at the Search: prompt is found, it places the, cursor beside it., ^T To Spell, Check for spelling errors. The spell check option allows, to correct spelling errors throughout the document. If spell, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
Page 95 : checker finds a misspelled word or a word it doesn't, recognize (don't worry, this rarely happens), it will correct, the word. At the Edit a replacement: prompt, type in the, correct spelling of a word. However, if you don't want to, make any changes, simply press the enter key., Any words that have corrected but re-occur in the document, can be automatically replaced. At the Replace a with b?, [y]: prompt press y to replace all occurrences of the, misspelled word or n to ignore., Pine Editor, pine is a program for accessing email and newsgroups., Syntax, pine [options] [address, address], Description, pine is a screen-oriented message-handling tool. In its, default configuration, pine offers an intentionally limited, set of functions geared toward the novice user, but it also, has a growing list of optional power-user and personalpreference features. pine's basic feature set includes:, , • View, Save, Export, Delete, Print, Reply and Forward, messages., , • Compose messages in a simple editor (pico) with wordwrap and a spelling checker. Messages may be, postponed for later completion., , • Full-screen selection and management of message, folders., , • Address book to keep a list of long or frequently-used, , addresses. Personal distribution lists may be defined., Addresses may be taken into the address book from, incoming mail without retyping them., , • New mail checking and notification occurs, automatically., , • Context-sensitive help screens., pine supports MIME (Multipurpose Internet Mail, Extensions), an Internet Standard for representing, multipart and multimedia data in email. pine allows you to, save MIME objects to files, and in some cases, can also, initiate the correct program for viewing the object. It uses, the system's mailcap configuration file to determine what, program can process a particular MIME object type. pine's, message composer does not have multimedia capability, , itself, but any type of data file (including multimedia) can, be attached to a text message and sent, using MIME's encoding rules. This allows any group of, individuals with MIME-capable mail software to exchange, formatted documents, spread-sheets, image files, etc, via, Internet email., pine uses the "c-client" messaging API to access local, and remote mail folders. This library provides a variety of, low-level message-handling functions, including drivers for, a variety of different mail file formats, as well as routines, to access remote mail and news servers, using IMAP, (Internet Message Access Protocol) and NNTP (Network, News Transport Protocol). Outgoing mail is usually handed, off to the send mail program but it can optionally be posted, directly via SMTP., Examples, Pine, Launch pine., pine
[email protected], Launch pine, and immediately begin composing an email, addressed to
[email protected]., Joe editor, 'joe'- sounds like a comic strip. Actually, they are two other, text editors that I like and I think are a little easier to, manage. They're like 'vi' in that you use them to create, and edit non-formatted text, but they're a little more userfriendly. Using 'joe' 'joe' was created by Joseph Allen, so, that's why it's called Joe., The majority of joe's commands are based on the CTRL-K, keys and a third key. The most important of these is CTRLK-H which gets 'help'. Help shows the key combinations, to use with 'joe'., The most important thing about 'joe' is the logical concept, that you can just start writing if you want. Try writing, anything you want., To save it, press CTRL-K-D. To save and quit, CTRL-K-X., To quit without saving, CTRL-C, (without the K)., The feature of 'joe' is that if edit a file again, it will save the, previous file with a tilde on the end, like 'tryjoe~' That little, tilde file has saved times. 'joe' is a very good option for, writing those short text files., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 79
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IT & ITES, Related Theory for Exercise 1.5.27 & 1.5.28, COPA - Linux Operating System, Managing files and directories, Objectives: At the end of this lesson you shall be able to, • define manipulating files and directories, • define basic file commands, • explain other file commands, • define additional useful commands in linux OS., Manipulating files or directories, Using Linux isn't different from any other computer, operating system. You create, delete, and move files on, your hard drive in order to organize your information and, manage how your system works or looks. This section, shows you how to do these tasks quickly and easily., Although the graphical interface for Linux, the X Window, System, may offer drag and drop or multiple selections in, order to copy or delete files, many of the commands you'll, learn here form the base of these operations. It is worth, knowing how these programs work, even if you don't use, Linux in the console mode., Working with files, In this chapter we learn how to recognise, create, remove,, copy and move files using commands like file, touch, rm,, cp, mv and rename, etc…, All files are case sensitive, Files on Linux (or any Unix) are case sensitive. This means, that FILE1 is different from, file1, and /etc/hosts is different from /etc/Hosts (the latter, one does not exist on a typical Linux computer)., The file command, The file command attempts to classify each filesystem, object (i.e., file, directory or link) that is provided to it as, an argument (i.e., input). Thus, it can usually provide, immediate information as to whether some specified, object is, for example, a GIF89a image file, a directory, a, GNU tar archive, ASCII English text, a symbolic link, an, HTML document, an empty file, bzip2 compressed data,, an ELF 32-bit LSB executable, etc., File accomplishes this by probing each object with three, types of tests until one succeeds. The first is a filesystem, test, which uses the stat system call to obtain information, from the object's inode (which contains information about, a file). A system call is a request in a Unix-like operating, system for a service performed by the kernel (i.e., the, core of the operating system)., The second test checks to see if there is a magic number,, which is a number embedded at or near the beginning of, many types of files that indicates the file format(i.e., the, type of file)., , it is plain text (i.e., composed entirely of human-readable, characters), and, if so, what type of plain text, such as, HTML (hypertext markup language) or source code (i.e.,, the original version of a program as written by a human)., In this situation, file also attempts to determine the natural, language (e.g., English, Turkish or Japanese) that is used, in the file., A simplified version of file's syntax is, file [option(s)] object_name(s), File has several options, but it is most commonly used, without any of them. For example, information about a file, named file1 that is located in the in the current directory, (i.e., the directory in which the user is currently working), could be obtained by merely typing the following and, pressing the RETURN key:, file file1, Information about the types of all of the files in the, current directory can be obtained by using the star wildcard, to represent every object in that directory as, follows:, file *, Likewise, information about all of the files in another, directory can be obtained by using that directory as an, argument and following it immediately by a forward slash, and the star wildcard. For example, the following, classifies all of the objects in the /boot directory:, file /boot/*, The square brackets wildcard can be used together with, the star wildcard to show the file types for only those, objects whose names begin with specified letters or with, a specified range of letters. For example, the following, would show only those objects in the current directory, whose names begin with letters a through g:, file [a-g]*, The -k option tells file to not stop at the first successful, test, but to keep going; this can result in the reporting of, additional information about some filesystem objects. The, -b (i.e., brief) option tells file to not prepend filenames to, output lines, which can be useful when compiling statistics, about file types. The -v option returns information about, the version of file that is installed., , In the event that the first two tests fail to determine the, type of a file, language tests are employed to determine if, 80, , Copyright @ NIMI Not to be Republished
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Creating files and directories command, mkdir command, The mkdir command is is used to create new, directories., A directory, referred to as a folder in some operating, systems, appears to the user as a container for other, directories and files. However, Unix-like operating, systemstreat directories as merely a special type of file, that contains a list of file names and their corresponding, inode numbers. Each inode number refers to an inode,, which is located in inode tables (which are kept at, strategic locations around the filesystem) and which, contains all information about a file (e.g., size,, permissions and date of creation) except its name and, the actual data that the file contains., mkdir has the following example, $ mkdir example, , mkdir -m 777 dir_4, The first digit represents the owner, the second represents, the group and the third represents other users. The number, 7 represents all three types of permission (i.e., read, write, and execute), 6 stands for read and write only, 5 stands, for read and execute, 4 is read only, 3 is write and execute,, 2 is write only, 1 is execute only and 0 is no permissions., Thus, for example, to create a new directory named dir_5, for which the owner has read and write permissions, the, group has read permission and other users have no, permissions, the following would be used:, mkdir -m 640 dir_5, , $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, directory_name is the name of any directory that the user, is asking mkdir to create. Any number of directories can, be created simultaneously., Thus, for example, the following command would create, three directories within the current directory (i.e., the, directory in which the user is currently working) with the, names dir_1, dir_2 and dir_3:, mkdir dir_1 dir_2 dir_3, If a directory name provided as an argument (i.e., input) to, mkdir is the same as that of an existing directory or file in, the same directory in which the user is asking mkdir to, create the new directory, mkdir will return a warning, message such as mkdir: cannot create directory `dir_1':, File exists and will not create a file with that name., However, it will then continue to create directories for any, other names provided as arguments., It is necessary for a user to have write permission (i.e.,, permission from the system to create or change a file or, directory) in the parent directory (i.e., the directory in which, the new directory is to be created) in order to be able to, create a new directory., Directories created by mkdir automatically include two, hidden directories, one representing the directory just, created (and represented by a single dot) and the other, representing its parent directory (and represented by two, consecutive dots). This can be seen by using the ls (i.e.,, list) command with its -a option, which tells ls to show all, directories and files, (including hidden ones) in any directory, provided to it as an argument, or in the current directory if, there are no arguments, i.e.,, ls -a, , a program) permissions enabled for the owner (i.e., the, creator of the directory by default) and group and the read, and execute permissions enabled for other users. Thus,, for example, to create a directory named dir_4 for which, all three types of permissions were enabled for all users,, the sequence 777 would be employed after -m, for example:, , The -p (i.e., parents) option creates the specified, intermediate directories for a new directory if they do not, already exist. For example, it can be used to create the, following directory structure:, mkdir -p food/fruit/citrus/oranges, It is very easy to confirm that this series of directories has, been created by using the du (i.e., disk usage) command, with the name of the first directory as an argument. In the, case of the above example this would be, du food, Other options include -v (i.e., verbose), which returns a, message for each created directory, --help, which returns, brief information about mkdir, and --version, which returns, the version number of the currently installed mkdir program, touch command, The touch command updates the access and modification, times of each FILE to the current system time., If you specify a FILE that does not already exist, touch, creates an empty file with that name., If the FILE argument is a dash ("-") is handled specially, and causes touch to change the times of the file associated, with standard output., $ touch file1 file2 file3, $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file2, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, A feature of touch is that, in contrast to some commands, such as cp (which is used to copy files and directories), and mv (which is used to move or rename files and, , mkdir's -m option is used to control the permissions of, new directories. New directories are by default created, with the read, write and execute (i.e., run as a program if, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 81
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directories), it does not automatically overwrite (i.e., erase, the contents of) existing files with the same name. Rather,, it merely changes the last access times for such files to, the current time., Several of touch's options are specifically designed to allow, the user to change the timestamps for files. For example,, the -a option changes only the access time, while the -m, option changes only the modification time. The use of both, of these options together changes both the access and, modification times to the current time, for example:, touch -am file3, The -r (i.e., reference) option followed directly by a space, and then by a file name tells touch to use that file's time, stamps instead of current time. For example, the following, would tell it to use the times of file4 for file5:, touch -r file4 file5, The -B option modifies the timestamps by going back the, specified number of seconds, and the -F option modifies, the time by going forward the specified number of seconds., For example, the following command would make file7 30, seconds older than file6., touch -r file6 -B 30 file7, The -d and -t options allow the user to add a specific last, access time. The former is followed by a string (i.e.,, sequence of characters) in the date, month, year,, minute:second format, and the latter uses a, [[CC]YY]MMDDhhmm[.ss] format. For example, to change, the last access time of file8 to 10:22 a.m. May 1, 2005, 1, May 2005 10:22 would be enclosed in single quotes and, used as follows, i.e.,:, touch -d '1 May 2005 10:22' file8, Partial date-time strings can be used. For example, only, the date need be provided, as shown for file9 below (in, which case the time is automatically set to 0:00):, touch -d '14 May' file9, Just providing the time, as shown below, automatically, changes the date to the current date:, touch -d '14:24' file9, The most commonly used way to view the last modification, date for files is to use the ls command with its -l option., For example, in the case of a file named file10 this would, be, ls -l file10, The complete timestamps for any file or directory can be, viewed by using the stat command. For example, the, following would show the timestamps for a file named file11:, stat file11, The --help option displays a basic list of options, and the, --version option returns the version of the currently installed, touch program., , 82, , Copy, move and remove commands, Copy command, The cp command is used to copy files and directories., The copies become independent of the originals (i.e., a, subsequent change in one will not affect the other)., cp's basic syntax is, $cp source destination, As a safety precaution, by default cp only copies files and, not directories. If a file with the same name as that assigned, to the copy of a file (or a directory with the same name as, that assigned to the copy of a directory) already exists, it, will be overwritten (i.e., its contents will be lost). However,, the owner, group and permissions for the copy become, the same as those of the file with the same name that it, replaced. The last access time of the source file and the, last modification time of the new file are set to the time, the copying was performed., When a copy is made of a file or directory, the copy must, have a different name than the original if it is to be placed, in the same directory as the original. However, the copy, can have the same name if it is made in a different directory., Thus, for example, a file in the current directory (i.e., the, directory in which the user is currently working) named, file1 could be copied with the same name into another, directory, such as into /home/john/, as follows:, cp file1 /home/john/file1, Any number of files can be simultaneously copied into, another directory by listing their names followed by the, name of the directory. cp is an intelligent command and, knows to do this when only the final argument (i.e., piece, of input data) is a directory. The files copied into the, directory will all have the same names as the originals., Thus, for example, the following would copy the files named, file2, file3 and file4 into a directory named dir1:, cp file2 file3 file4 dir1, The -r (i.e., recursive) option, which can also be written, with an upper case R, allows directories including all of, their contents to be copied. (Directories are not copied by, default in order to make it more difficult for users to, accidentally overwrite existing directories which have the, same name as that assigned to the copy being made and, which might contain critical directory structures or, important data.) Thus, for example, the following command, would make a copy of an existing directory called dir2,, inclusive of all it contents (i.e., files, subdirectories, their, subdirectories, etc.), called dir3:, cp -r dir2 dir3, The -i (i.e., interactive) option prompts the user in the event, that any name assigned to a copy is already in use by, another file and that file would thus be overwritten. Entering, the letter y (either lower case or upper case) in response, to the prompt causes the command to continue; any other, answer prevents the command from overwriting the file., Thus, for example, if it is desired to make a copy of a, directory called dir4 and call it dir5 and if a directory named, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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dir4 already exists, the following would prompt the user, prior to replacing any files with identical names in the latter, directory:, cp -ri dir4 dir5, The -a option preserves as much of the structure and, attributes of the original directory and its contents as, possible in the new directory and is thus useful for creating, archives. It is similar to the -r option in that it copies, directories recursively; however, it also never follows, symbolic links. It is equivalent to the -rdp combination of, options., All the files in a directory can be copied to another directory, by using the star wildcard. The star character represents, any single character or any combination of characters., Thus, for example, the following would copy all of the files, in a directory named dir6 into another existing directory, called dir7:, cp dir6/* dir7, cp can also be used with the star wildcard or other pattern, matching characters to selectively copy files and, directories. For example, to copy all of the files in the, current directory that have the filename extension .html, into another existing directory called dir8, the following, would be used:, cp *.html dir8, In this case, the star wildcard represents anything whose, name ends with the .html extension., Among the other options for cp are -b, which makes backup, copies of each destination file, -f (i.e., force), which removes, destination files that cannot be opened and tries again, s, which makes symbolic links instead of copying, -u (i.e.,, update), which copies only if the source file is newer than, the destination file or if the destination file is missing, -v, (i.e., verbose), which makes brief comments about what, is going on, and -x, which tells cp to stay on the same, filesystem., Move command, The mv command is used to rename and move files and, directories. Its general syntax is:, $ mv source destination, The arguments are names of files and directories. If two, file names are provided as arguments, mv renames the, first as the second. If a list of arguments is provided and, the final argument in the sequence is the name of an, existing directory, mv moves all of the other items into, that directory. If the final argument is not an existing, directory and more than two arguments are provided, an, error message is returned., If the destination file is located in the same directory as, the source file, then the source file can only be renamed., If both are in different directories, then the source file is, moved to the directory named in the destination argument,, in which it can keep its original name or be assigned a, new name. If the target is a directory, then the source file, , or directory is moved into that directory and retains its, original name., Thus, for example, the following would rename a file called, file1 to file2, while keeping it in the current directory (i.e.,, the directory in which the user is currently working):, mv file1 file2, The following would move a file named file3, without, changing its name, from the current directory to an existing, subdirectory of the current directory named dir1:, mv file3 dir1/file3, mv can be used to move any number of files and directories, simultaneously. For example, the following command, moves all files and directories, including all the contents, of those directories, from the current directory to the, directory /home/alice/new/:, mv * /home/alice/new/, The asterisk is a wildcard character that represents any, string (i.e., sequence of characters). Thus, in the above, example it represents the name of every file and directory, in the current directory., mv makes it as easy to move a file or directory up the, hierarchy of directories (i.e., closer to the root directory), as down it. For example, the following would move a file, named file4, which is currently located in the subsubdirectory dir/dir/ of the user's home directory, to the, top level in the user's home directory:, mv dir/dir/file4 ~, The root directory is the directory that contains all other, directories on a Unix-like operating system and which is, at the top of the hierarchy of directories. A user's home, directory is the directory in which a user finds itself by, default after logging into the system and which can be, represented by the tilde (wavy horizontal linecharacter)., By default, mv does not provide any confirmation on the, display screen if its action is completed without problems., This is consistent with the rule of silence tenet of the Unix, philosophy., Thus it is wise for users new to Unix-like operating, systems to always use the -i option, which makes mv, interactive in the situation in which files and/or directories, with the same name already exist in the destination, directory. For example, the above command would be made, interactive as follows:, mv -i * /home/alice/new/, Among mv's few other options are -b, which tells it to make, a backup copy of each file that would otherwise be, overwritten or removed, and -v, which tells it to beverbose, and display the name of each file before moving it. Detailed, information (including all options) about mv can be obtained, by using its --help option, and information about the current, version can be obtained by using its --version option., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 83
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Remove or Delete, , begins with a dash or hyphen. For example, the following, removes a directory named -dir1:, , $ rmdir, 'rmdir' command removes any empty directories, but, cannot delete a directory if a file is present in it. To use, 'rmdir' command, you must first remove all the files present, the directory you wish to remove (and possibly directories, if any)., Remove files and directories, The rm (i.e., remove) command is used to delete files and, directories on Linux and other Unix-like operating systems., The general syntax for rm is:, rm [options] [-r directories] filenames, The items in square brackets are optional. When used, just with the names of one or more files, rm deletes all, those files without requiring confirmation by the user. Thus,, in the following example, rm would immediately delete the, files named file1, file2 and file3, assuming that all three, are located in the current directory (i.e., the, directory in which the user is currently working):, rm file1 file2 file3, Error messages are returned if a file does not exist or if, the user does not have the appropriate permission to delete, it. Write-protected files prompt the user for a confirmation, (with a y for yes and an n for no) before removal. Files, located in write-protected directories can never be removed,, even if those files are not write-protected., The -f (i.e., force) option tells rm to remove all specified, files, whether write-protected or not, without prompting the, user. It does not display an error message or return error, status if a specified file does not exist. However, if an, attempt is made to remove files in a write-protected, directory, this option will not suppress an error message., The -i (i.e., interactive) option tells rm to prompt the user, for confirmation before removing each file and directory. If, both the -f and -i options are specified, the last one specified, takes affect., As a safety measure, rm does not delete directories by, default. In order to delete directories, it is necessary to, use the -r option, which is the same as the -R option. This, option recursively removes directories and their contents, in the argument list; that is, the specified directories will, first be emptied of any subdirectories (including their, subdirectories and files, etc.) and files and then removed., The user is normally prompted for removal of any writeprotected files in the directories unless the -f option is, used., If a file encountered by rm is a symbolic link, the link is, removed, but the file or directory to which that link refers, will not be affected. A user does not need write permission, to delete a symbolic link, as long as the user has write, permission for the directory in which that link resides., The rm command supports the -- (two consecutive dashes), parameter as a delimiter that indicates the end of the, options. This is useful when the name of a file or directory, 84, , rm -r -- -dir1, Other options include -v (i.e., verbose), which provides, additional information about what is happening, --help,, which provides basic documentation about rm, and -version, which tells the version of rm that is currently in, use. Some differences exist among the various versions, of rm, so it is always wise to read the documentation for, the particular system., The rmdir command differs from rm in that it is only used, to remove empty directories, The rmdir command, The rmdir command is used to remove empty directories, in Linux, The syntax for rmdir is, rmdir [option] directory_names, When used without any options, rm will delete any empty, directories whose names are supplied as arguments (i.e.,, inputs) regardless of whether such directories have write, permission or not. Thus, for example, the following, command would remove two empty directories named dir1, and dir2 that are located in the current directory (i.e., the, directory in which the user is currently working):, rmdir dir1 dir2, The ability to remove only empty directories is a built-in, safeguard that helps prevent the accidental loss of data., This is important because once deleted, it is extremely, difficult or impossible to recover deleted data on Unix-like, operating systems1., The -p (i.e., parents) option tells rmdir to remove the parent, directories of the specified directory if each successive, parent directory will, in turn, become empty and if each, parent directory has write permission. Thus, for example,, the following would remove dir5, dir4 and dir3 if dir5 were, empty, dir4 only contained dir5 and dir3 only contained, dir4 (which, in turn, contained dir5):, rmdir -p dir3/dir4/dir5, This provides a symmetry with the -p option of the mkdir, command, which is used to create directories. Thus, the, above set of nested directories could be easily created, with the following:, mkdir -p dir3/dir4/dir5, In contrast to the rm command, which is used to delete, both files and directories, there is no -r option for rmdir. at, least on the GNU version that is standard on Linux. That, option allows rm to recursively delete a directory by first, deleting all of its contents, beginning with those in the, lowest levels of subdirectories. Thus, if a user wants to, remove an entire directory structure, it is usually most, efficient to use rm with its -r option rather than trying to, first remove the contents of each directory, its, subdirectories, etc., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Three options that rmdir shares with rm are -v (i.e., verbose),, which provides additional information about what is, happening, --help, which provides basicdocumentation, about rmdir, and --version, which tells the version of rmdir, that is currently in use. Some differences exist among the, various versions of rmdir, so it is always wise to read the, documentation for the particular system., Listing and combining files with the cat command, The cat (concatenate file) command is used to send the, contents of files to your screen. This, command may also be used to send files' contents into, other files. Hour 6 covers terms such as standard input,, standard output, and redirection, and this section shows, you some basic uses for this command., Although cat may be useful for reading short files, it is, usually used to either combine, create, overwrite, or, append files. To use cat to look at a short file, you can, enter, $ cat test.txt, This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., The cat command also has a number of options. If you'd, like to see your file with line, numbers, perhaps to note a specific phrase, you can use, the -n option:, , $ cat test.txt test2.txt, The output will be exactly the same as if had used a, wildcard. But looking at several files is only one way to, use cat. You can also use the cat command with the, redirection operator > to combine files. For example, if, you would like to combine test.txt and test2.txt into a, third file called test3.txt, you can use, $ cat test* > test3.txt, check the result with, # ls -l test*, In this case, user first decide whether you want the contents, of test.txt to go into test2.txt, or the contents of test2.txt, to go into test.txt . Then, using cat with the >> redirection, operator, you might type, $ cat test.txt >> test2.txt, This appends the contents of test.txt to the end of the, test2.txt . To check the results, use cat again:, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., Note that if you had entered the command., , $ cat -n test.txt, , • This text file was created by the cat command., • Cat could be the world's simplest text editor., • If you read this book, you'll learn how to use cat., • This is the last line of text in this file., and also use cat to look at several files at once, because, cat accepts wildcards, for example:, , $ cat -n test.txt >> test2.txt, The test2.txt file would look like, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., , $ cat -n test*, , • This text file was created by the cat command., , • This text file was created by the cat command., , • Cat could be the world's simplest text editor., , • Cat could be the world's simplest text editor., , • If you read this book, you'll learn how to use cat., , • If you read this book, you'll learn how to use cat., , • This is the last line of text in this file., , • This is the last line of text in this file., • This file was also created by cat., , Finally, here's a trick you can use if you want to create a, short text file without running a word processor or text, editor. Because the cat command can read the standard, input (more about this in Hour 6), you can make the cat, command create a file and fill it with your keystrokes., , • This is the last line of test2.txt., , Here's how:, , • This is the first line of test2.txt., , As you can see, cat has also included a second file in its, output, and has numbered each line of the output, not, each file. Note that also see both files with, , $ cat > myfile.txt, Now, enter some text:, $ cat > myfile.txt, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 85
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This is the cat word processor., This is the end of the file., Then, when you're done typing, press Ctrl+D to close the, file. To see if this works, try, $ ls -l myfile.txt, -rw-rw-r-- 1 bball bball 61 Nov 12 18:26 myfile.txt, $ cat myfile.txt, This is the cat word processor., This is the end of the file., user should also know that the cat command will print out, the contents of any file, and not, just text files. Although cat may be useful to look at one or, several short files,, Other file commands, The clear Command, The clear command is used to remove all previous, commands and output from consoles and terminal, windows in Unix-like operating systems., A console is an all-text mode user interface that, occupies the entire screen of the display device and which, does not sit on top of a graphical user interface (GUI). A, terminal window is a text-only window in a GUI that, emulates a console and which can be opened by clicking, the appropriate icon (i.e., small image) or menu item., , As another example, the following displays the man page, about the man pages:, man man, man automatically sends its output through a pager,, usually the program less. A pager is a program that causes, the output of any program to be displayed one screenful, at a time, rather than having a large amount of text scroll, down the screen at high (and generally unreadable) speed., less writes a colon at the bottom of the screen to indicate, the end of the on-screen page. The user can move to the, next page by pushing the space bar and can return to the, previous page by pressing the b key. Pressing the q exits, the man pages and returns the user to the shell program., Each man page is a self-contained article that is divided, into a number of sections, the headers for which are labeled, with upper case letters. The sections for commands are, typically something like NAME, SYNOPSIS,, DESCRIPTION, OPTIONS, AUTHOR, BUGS,, COPYRIGHT, HISTORY and SEE ALSO, although there, may be some differences according to the particular, command. Some of these might be broken down into, subsections, particularly OPTIONS in the case of a, command that has numerous options., Also, the man pages as a whole are organized into, sections, each containing pages about a specific category, of topics as shown below. The section to which an article, belongs is indicted in parenthesis in the top line, before, the NAME header., , Clear is one of the very few commands in Unix-like, operating systems that accepts neither options nor, arguments (i.e., input files). That is, it is only used as, follows:, , 1. executable programs or shell commands, , Clear, , 4. special files (i.e., devices in the /dev directory), , After the clear command has been issued, all that, remains on the display screen is the command prompt in, the upper left hand corner. A command prompt, also, referred to as a prompt, is a short text message at the, start of a line that informs the user that the system is, ready for the next command, data element or other, input., , 5. file formats, , The descriptions are rather terse, and they can seem, somewhat cryptic to new users. However, users typically, find them to be increasingly useful as they become more, familiar with them and gain experience in the use of Unixlike operating systems., , Some topic names will have multiple articles, depending, on context. For instance, there are two articles for mount,, one corresponding to its use as a command in system, management (i.e., to logically attach partition or other, devices to the main filesystem) and the other for use in, the C programming language. Generally, the most, commonly used topic is displayed by default, and there, are references to any other topics with the same name in, the SEE ALSO section at the bottom of the final on-screen, page., , The man command itself is extremely easy to use. Its, basic syntax is, man [option(s)] keyword(s), man is most commonly used without any options and, with only one keyword. The keyword is the exact name of, the command or other item for which information is desired., For example, the following provides information about the, ls command (which is used to list the contents of any, specified directory):, man ls, 86, , 2. system calls, 3. library routines, , 6. games, 7. macro packages, 8. system administration commands, 9. kernel routines, , The syntax to specify an article from a particular section, is:, man section_number keyword, , Thus, for example, the following would display the article, about mount from Section 2 instead of from the default, Section 8:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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man 2 mount, The -w and -W options tell man to not actually display the, man pages, but to provide the location(s) of the file(s) that, would be formatted or displayed. If noarguments (i.e., input, files) are provided, a list of directories that is searched by, man for man pages is returned., The -f option produces the same output as the whatis, command. whatis provides very brief descriptions of, commands from a database that is automatically created, from the first line of the NAME section of each relevant, man page., The Whoami and who command, The whoami command writes the user name (i.e., login, name) of the owner of the current login session to standard, output. Standard output is, by default, the display screen,, unless redirected to a file, printer, etc., , as additional information about each of those users, (including login times and terminal numbers). It also, differs in that, in the event of a change in ownership of a, login session through the use of the su command, it, reports the original owner of the session, whereas whoami, provides the user name of the effective (i.e., current) owner, of the session., stat command, File Stat - Display Information About File, For example, to find out more information about, 101hacks.txt file, execute the stat command as shown, below., $ stat 101hacks.txt, File: `/home/sathiyamoorthy/101hacks.txt', Size: 854, , Blocks: 8 IO Block: 4096 regular file, , whoami is particularly useful when using shells such as, ash and sh that do not show the name of the current user, in the command prompt (a short text message at the start, of the command line on an all-text display). It is also useful, for confirming the current owner of a session after using, the su (i.e., substitute user) command, which changes, the owner of the session without the original owner having, to first log out., , Device: 801h/2049d, , A shell is a program that provides the traditional, text-only, user interface forUnix-like operating systems. Its primary, function is to read commands that are typed into a console, (i.e., an all-text display mode) or terminal window(an alltext window in a GUI) and then execute (i.e., run) them., , Details of Linux stat command output, , The formal syntax for whoami is:, , • Blocks: 8 - Total number of blocks used by this file., , whoami [option], When used without any options or redirection, as it usually, is, i.e.,, Whoami, , Inode: 1058122, , Links: 1, , Access: (0600/-rw-------) Uid: ( 1000/ sathiya), Gid: ( 1000/ sathiya), Access: 2009-06-28 19:29:57.000000000 +0530, Modify: 2009-06-28 19:29:57.000000000 +0530, Change: 2009-06-28 19:29:57.000000000 +0530, , • File: `/home/sathiyamoorthy/101hacks.txt' - Absolute, path name of the file., , • Size: 854 - File size in bytes., • IO Block: 4096 - IO block size for this file., • Regular file - Indicates the file type. This indicates, , that this is a regular file. Following are available file, types., , and followed by pressing the ENTER key, whoami displays, on the monitor screen the user name of the owner of the, current session., , − regular file. ( ex: all normal files )., , There are only two options for whoami: --help and --version., The former outputs the very brief description that is, contained in the man (i.e., built-in system manual) pages,, and the latter outputs the number of the version currently, installed on the system., , − socket. ( ex: sockets )., , whoami produces the same result as the id command, (which by default provides more detailed information about, the current user than does whoami) when id is used with, its -u and -n options, i.e.,, , − character special file. ( ex: terminal device file)., , id -un, The -u option tells id to provide only the identification for, the current owner of the session, and the -n option tells it, to present that identification as the user name instead of, as a number., The who command differs from whoami in that it provides, a list of all users currently logged into the system as well, , − directory. ( ex: directories )., − symbolic link. ( ex: symbolic links. ), − block special file ( ex: hard disk )., • Device: 801h/2049d - Device number in hex and device, number in decimal, , • Inode: 1058122 - Inode number is a unique number for, , each file which is used for the internal maintenance by, the file system., , • Links: 1 - Number of links to the file, • Access: (0600/-rw---): Access specifier displayed in, , both octal and character format. Let us see explanation, about both the format., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 87
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• Uid: ( 1000/ sathiya) - File owner's user id and user, , between. Thus, the following command would produce the, same result:, , • Gid: ( 1000/ sathiya) - File owner's group id and group, , head -n 15 aardvark armadillo, , name are displayed., name are displayed., , • Access: 2009-06-28 19:29:57.000000000 +0530 - Last, access time of the file., , • Modify: 2009-06-28 19:29:57.000000000 +0530 - Last, modification time of the file., , • Change: 2009-06-28 19:29:57.000000000 +0530 - Last, change time of the inode data of that file., , Dir Stat - Display Information About Directory You can, use the same command to display the information about, a directory as shown below., $ stat /home/ramesh, , In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell head how many lines to, return. Thus, the following would produce the same, result as the above commands:, head -15 aardvark armadillo, head can also return any desired number of bytes (i.e., a, sequence of eight bitsand usually long enough to represent, a single character) from the start of each file rather than a, desired number of lines. This is accomplished using the coption followed by the number of bytes desired. For, example, the following would display the first five bytes of, each of the two files provided:, , File: `/home/ramesh', , head -c 5 aardvark anteater, , Size: 4096 Blocks: 8 IO Block: 4096 directory, , When head counts by bytes, it also includes the newline, character, which is anon-printing (i.e, invisible) character, that is designated by a backslash and the letter n (i.e.,, \n). Thus, for example, if there are three new, blank lines, at the start of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or on, paper)., , Device: 803h/2051d Inode: 5521409 Links: 7, Access: (0755/drwxr-xr-x) Uid: ( 401/ramesh), Gid: (401/ramesh), Access: 2009-01-01 12:17:42.000000000 -0800, Modify: 2009-01-01 12:07:33.000000000 -0800, Change: 2009-01-09 12:07:33.000000000 -0800, The head command reads the first few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the display screen)., , The number of bytes or lines can be followed by a, multiplier suffix. That is, adding the letter b directly after, the number of bytes multiplies it by 512, kmultiplies it by, 1024 and m multiplies it by 1048576. Thus, the following, command would display the first five kilobytes of the file, aardvark:, , head's basic syntax is:, , head -c5k aardvark, , head command, , head [options] [file(s)], The square brackets indicate that the enclosed items are, optional. By default, head returns the first ten lines of each, file name that is provided to it., For example, the following will display the first ten lines of, the file namedaardvark in the current directory (i.e., the, directory in which the user is currently working):, head aardvark, If more than one input file is provided, head will return the, first ten lines from each file, precede each set of lines by, the name of the file and separate each set of lines by one, vertical space. The following is an example of using head, with two input files:, head aardvark armadillo, If it is desired to obtain some number of lines other than, the default ten, the -noption can be used followed by an, integer indicating the number of lines desired. For example,, the above example could be modified to display the first, 15 lines from each file:, head -n15 aardvark armadillo, , The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter ccannot be omitted as, can the letter n, because in such case head would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like head: aardvark: invalid number of bytes:, head -c aardvark, If head is used without any options or arguments (i.e., file, names), it will await input from the keyboard and will, successively repeat (i.e., each line will appear twice) on, the monitor screen each of the first ten lines typed on the, keyboard. If it were desired to repeat some number of, lines other than the default ten, then the -n option would, be used followed by the integer representing that, number of lines (although, again, it is not necessary to, include the letter n), e.g.,, head -n3, As is the case with other command line (i.e., all-text mode), programs in Linuxand other Unix-like operating systems,, the output from head can redirectedfrom the display monitor, to a file or printer using the output redirection operator, (which is represented by a rightward-pointing angular, , -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, 88, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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bracket). For example, the following would copy the first, 12 lines of the file Yuriko to the fileDecember:, head -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two consecutive rightward pointing angle brackets) could, be used to add the output from head to the end of a file, with that name if it already existed (or otherwise create a, new file with that name), i.e.,, head -n 12 Yuriko >> December, The output from other commands can be sent via a pipe, (represented by thevertical bar character) to head to use, as its input. For example, the following sends the output, from the ls command (which by default lists the names of, the files and directories in the current directory) to head,, which, in turn, displays the first ten lines of the output that, it receives from ls:, ls | head, This output could easily be redirected, for example to the, end of a file namedfile1 as follows:, ls | head >> file1, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reverse alphabetic order, prior to appending file1:, ls | head | sort -r >> file1, The -q (i.e., quiet) option causes head to not show the file, name before each set of lines in its output and to eliminate, the vertical space between each set of lines when there, are multiple input sources. Its opposite, the -v (i.e., verbose), option, causes head to provide the file name even if there, is just a single input file., The tail command is similar to the head command except, that it reads the final lines in files rather than the first, lines., As is the case with other commands on Unix-like operating, systems, additional information can be obtained about head, and tail by using the man and infocommands to reference, the built-in documentation, for example, man head, or, info tail, tail command, The tail command reads the final few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the monitor screen)., The basic syntax for tail is:, tail [options] [filenames], $ tail -n 4 /etc/passwd, , The square brackets indicate that the enclosed items are, optional. By default, tail returns the final ten lines of each, file name that is provided to it., For example, the following command will print (traditional, Unix terminology for write) the last ten lines of the file, named aardvark in the current directory (i.e., the director, in which the user is currently working) to the display, screen:, tail aardvark, If more than one input file is provided, tail will print the last, ten lines from each file to the monitor screen. Each set of, lines will be preceded by the name of the file and separated, by one vertical space from other sets of lines. The following, is an example of using tail with multiple input files:, tail file1 file2 file3, If it is desired to print some number of lines other than the, default ten, the -n option can be used followed by an integer, indicating the number of lines desired. For example, to, print the final 15 lines from each file in the above example,, the command would be modified as follows:, tail -n15 file1 file2 file3, -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, between. Thus, the following command would produce the, same result:, tail -n 15 file1 file2 file3, In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell tail how many lines to print. Thus, the, following would produce the same result as the above, commands:, tail -15 file1 file2 file3, tail can also print any desired number of bytes (i.e., a, sequence of eight bits and usually long enough to represent, a single character) from the end of each file rather than a, desired number of lines. This is accomplished using the c option followed by the number of bytes desired. For, example, to view the final five bytes of each of the two files, aardvark and anteater, the following command would be, used:, tail -c 5 file1 file2, When tail counts by bytes, it also includes the newline, character, which is a non-printing (i.e, invisible) character, that is designated by a backward slash and the letter n, (i.e., \n). Thus, for example, if there are three new, blank, lines at the end of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or paper)., The number of bytes or lines can be followed by a multiplier, suffix. That is, adding the letter b directly after the number, of bytes multiplies it by 512, k multiplies it by 1024 and m, multiplies it by 1048576. Thus, the following command, would print the last five kilobytes of the file aardvark:, tail -c5k file1, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 89
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The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter c cannot be omitted as, can the letter n, because in such case tail would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like tail: aardvark: invalid number of bytes:, tail -c file1, If tail is used without any options or arguments (i.e., inputs),, it will await input from the keyboard and will successively, repeat (i.e., each line will appear twice) on the monitor, screen each of the final ten lines typed on the keyboard. If, it were desired to repeat some number of lines other than, the default ten, then the -n option would be used followed, by the integer representing that number of lines (although,, again, it is not necessary to include the letter n), e.g.,, tail -n3, As is the case with other command line (i.e., all-text mode), programs in Unix-like operating systems, the output of, tail can be redirected from the monitor to a file or printer, using the redirection operator (which is represented by a, rightward pointing angular bracket). For example, the, following would write the final 12 lines of the file Yuriko to, the file December:, tail -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two rightward pointing angular brackets) could be used to, add the output from tail to the end of a file with that name, if it already existed (or otherwise create a new file with, that name), i.e.,, tail -n 12 Yuriko >> December, The output from other commands can be piped (i.e., sent), to tail to use as its input. For example, the following sends, the output from the ls command (which by default lists the, names of the files and directories in the current directory), to tail, which, in turn, prints the final ten lines of the output, that it receives from ls to the monitor screen:, ls | tail, , Tail can be instructed to begin printing from some number, of lines or bytes from the start of a file by preceding the, number with a plus sign instead of a minus sign. For, example, the following would print each of the designated, files to the display monitor beginning with the seventh line, and until the end:, tail +7 file1 file2 file3, The c option could be used to tell tail to print each of the, designated files beginning with the seventh byte instead, of the seventh line:, tail +7c file1 file2 file3, A particularly common application for tail is examining the, most recent entries in log files. This is because the newest, entries are appended to the ends of such files, which tail, excels in showing. As log files can be a rather long, this, can eliminate a lot of scrolling that would be necessary if, some other command were used to read them. For, example, the most recent entries to the log /var/log/, messages can easily be viewed by using the, following:, tail /var/log/messages, wc command, The wc (i.e., word count) command by default counts the, number of lines, words and characters in text., wc defines a word as a set of contiguous letters, numbers, and/or symbols which are separated from other characters, by one or more spaces, tabs and/or newline characters, (which are generated when the RETURN key is pressed)., When counting the number of characters, all characters, are counted, not only letters, numbers and symbols, but, also spaces, tabs and newline characters. A line is only, counted if it ends with a newline character., wc's syntax is, , This output could easily be redirected, for example to a, file named last_filenames as follows:, ls | tail >> last_filenames, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reversealphabetic order, prior to writing to a file:, ls | tail | sort -r >> last_filenames, The -q (i.e., quiet) option causes tail to not print the file, name before each set of lines and to eliminate the vertical, space between each set of lines when there are multiple, input sources. The -v (i.e., verbose) option causes tail to, print the file name even if there is just a single input file., 90, , Tail could be viewed as a counterpart of the head command,, which always starts reading from the beginning of files, and which can continue until any specified distance from, the beginning. However, there are a few differences. Perhaps, the most useful of these is that tail is somewhat more, flexible in that, in addition to being able to start reading, any specified distance from the end of a file, it can also, start at any specified distance from the beginning of a file., , wc [options] [file_name(s)], The items in square brackets are optional. If no file names, are provided, wc reads from its standard input, which by, default is text entered at the keyboard., This can be seen by typing., wc, at the command line (i.e., in the all-text mode), pressing, the ENTER key to move to a new line and then typing, some text on one or more lines. The command isexecuted, (i.e., run) by pressing the ENTER key again and then, pressing the CONTROL and d keys simultaneously. This, causes wc to write in a new line (under the lines of text), its count of the numbers of lines, words and characters in, the text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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The following command counts the number of lines, words, and characters in a file named file1 that resides in the, current directory (i.e., the directory in which the user is, currently working) and likewise writes them, followed by, the name of the file, to standard output, which is by default, the display monitor:, , cat file6, grep command, grep is used to search text for patterns specified by the, user. It is one of the most useful and powerful commands, on Linux and other Unix-like operating systems., grep's basic syntax is:, , wc file1, wc can provide its output for multiple files by listing the, name of each separated by a space. For example,, wc file1 file2 file3, The numbers of lines, words and characters for each file, along with its name will be displayed on a separate line, and in the order that the files are listed as arguments(i.e.,, input files). In the case of multiple arguments such as, this, wc also provides an additional line that shows the, total number of lines, words and characters for all the files., Likewise, wc can provide a count for all of the text files, within a directory. This is accomplished by using the star, wildcard character, which represents everythingand is, designated by an asterisk ( * ). For example, the following, will display the number of lines, words and, characters for each file in the current directory (which is, represented by a dot) as well as totals for all files in the, directory:, wc . *, wc has only a few options, the most commonly used of, which restrict the information it provides. The -l option tells, wc to count only the number of lines, the -woption tells it, to count only the number of words, the -m option tells it to, count only the number of characters and the -c option, tells wc to count only the number ofbytes. Thus, for, example, the following displays just the number of words, in a file named file4:, wc -w file4, The following displays the number of characters in the, same file:, wc -m file4, As is generally the case with commands in Unix-like, operating systems, any combination of options can be, used together. For example, the following would count both, the numbers of lines and words in a file named file5:, wc -lw file5, Redirection can be used with wc to create more complex, commands. For example, the output from the above, command can be redirected using the standard output, redirection operator (which is designated by a rightward, pointing angle bracket) from the display screen to a file, named file6 with the following:, wc -lw file5 > file6, If file6 already exists, its contents will be overwritten; if it, does not exist, it will be created. The contents of file6 can, be easily confirmed with a text editor or with a command, such as cat, which is commonly used to read text files,, i.e.,, , grep [option(s)] pattern [file(s)], The items in square brackets are optional. When used, with no options and no arguments (i.e., input files), grep, searches standard input (which by default is text typed in, at the keyboard) for the specified pattern and returns each, line that contains a match to standard output (which by, default is the display screen)., A line of text is defined in this context not as what, appears as a line of text on the display screen but rather, as all text between two newline characters. Newline, characters are invisible characters that are represented in, Unix-like operating systems by a backslash followed by, the letter n and which are created when a user presses, the ENTER key when using a text editor (such as gedit)., Thus, a line of text returned by grep can be as short as a, single character or occupy many lines on the display, screen., grep can search any number of files simultaneously. Thus,, for example, the following would search the three files file1,, file2 and file3 for any line that contains thestring (i.e.,, sequence of characters) Lin:, grep Lin file1 file2 file3, Each result is displayed beginning on a separate line, and, it is preceded by the name of the file in which it was found, in the case of multiple files. The inclusion of the file names, in the output data can be suppressed by using the -h, option., grep is not limited to searching for just single strings. It, can also search for sequences of strings, including, phrases. This is accomplished by enclosing the sequence, of strings that forms the pattern in quotation marks (either, single or double). Thus, the above example could be, modified to search for the phrase Linux is:, grep 'Linux is' file1 file2 file3, Text searches with grep can be considerably broadened, by combining them with wildcards and/or performing, recursive searches. A wildcard is a character that can, represent some specific class of characters or sequence, of characters. The following is a modification of the above, example that uses the star wildcard (i.e., an asterisk),, which represents any character or sequence of characters,, to search all text files in the current directory (i.e., the, directory in which the user is currently working):, grep 'Linux is' *, , grep's search area can be broadened even further by using, its -r option to search recursively through an entire directory, tree (i.e., a directory and all levels of subdirectories within, it) rather than just the files within a specified directory. For, example, the following would search all files in the current, 91, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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directory and in all of its subdirectories (including their, subdirectories, etc.) for every line containing the full name, of the creator of Linux:, grep -r 'Linus Torvalds' *, One of the most commonly employed of grep's many, options is -i, which instructs it to ignore case, that is, to, ignore whether letters in the pattern and text searched are, lower case (i.e., small letters) or upper case (i.e., capital, letters). Thus, for instance, the previous example could, very easily be converted to a case-insensitive search as, follows:, grep -ir 'Linus Torvalds' *, This would produce the same results as, grep -ir 'linUS torvAlds' *, Another frequently used option is -c, which causes grep, to only report the number of times that the pattern has, been matched for each file and to not display the actual, lines. Thus, for instance, the following would show the, total number of times that the string inu appears in a file, named file4:, grep -c inu file4, Another useful option is -n, which causes grep to precede, each line of output with the number of the line in the text, file from which it was obtained. The -v option inverts the, match; that is, it matches only those lines that do not, contain the given pattern., The -w option tells grep to select only those lines that, contain an entire word or phrase that matches the, specified pattern. The -x option tells grep to select only, those lines that match exactly the specified pattern., The -l option tells grep to not return the lines containing, matches but to only return only the names of the files that, contain matches. The -L option is the opposite of the -l, option (and analogous to the -v option) in that it will cause, grep to return only the names of files that do not contain, the specified pattern., grep does not search the names of files for a specified, pattern, only the text contained within files. However,, sometimes it is useful to search the names of files, as, well as of directories and links, rather than the contents of, files. Fortunately, this can easily be accomplished by first, using the ls command to list the contents of a directory, and then using a pipe (which is represented by the vertical, bar character) to transfer its output to grep for searching., For example, the following would provide a list of all files,, directories and links in the current directory that contain, the string linu in their names:, ls | grep linu, The following example uses ls with its -l (i.e., long) option, (which is unrelated to grep's -l option) to find all filesystem, objects in the current directory whose permissions have, been set so that any user can read, write and execute, them:, ls -l | grep rwxrwxrwx, 92, , grep is very useful for obtain information from log and, configuration files. For example, it can be used to obtain, information about the USB (universal serial bus) devices, on a system by filtering the output from the dmesg, command (which provides the messages from the kernel, as a system is booting up) as follows:, dmesg | grep -i usb, Among grep's other options are --help, which provides a, very compact summary of some of its many capabilities,, and -V, or --version, which provides information about the, currently installed version., grep's search functionality can be even further refined, through the use of regular expressions. These are a pattern, matching system that uses strings constructed according, to pre-defined syntax rules to find desired patterns in text., Additional information about grep, including its use with, regular expressions, can be obtained from its built-in, manual page by using the man command, i.e.,, man grep, The name grep comes from a command in ed, which was, the original text editor on the UNIX operating system. The, command takes the form g/re/p, which means to search, globally for matches to the regular expression (i.e., re),, and print (which is UNIX terminology for write on the display, screen) lines that are found., ln command, ln command is used to create links. Links are a kind of, shortcuts to other files. The general form of command is:, $ ln TARGET LINK_NAME, There are two types of links, soft links and hard links. By, default, hard links are created. If you want to create soft, link, use -s option. In this example, both types of links are, created for the file usrlisting., $ ln usrlisting hard_link, $ ln -s usrlisting soft_link, $ ls -l, total 12, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 hard_link, lrwxrwxrwx 1 raghu raghu 10 2012-07-09 14:00 soft_link > usrlisting, -rw-r--r-- 1 raghu raghu 491 2012-07-06 16:02 usrcopy, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 usrlisting, Some additional useful commands, alias command, 'alias' is another name for a command. If no argument is, given, it shows current aliases. Aliases can be used for, short names of commands. For example, you might use, clear command frequently. You can create an alias for it:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ alias c="clear", Next time enter c on command line, your screen will be, clear. Current aliases can be checked with 'alias', command:, $ alias, alias alert='notify-send --urgency=low -i "$([ $? = 0 ] &&, echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/, ^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"', alias c='clear', alias egrep='egrep --color=auto', alias fgrep='fgrep --color=auto', alias grep='grep --color=auto', alias l='ls -CF', alias la='ls -A', alias ll='ls -alF', alias ls='ls --color=auto', w command, The w command shows who is logged in to the system, and what they are doing., A login, logging in or logging on is the entering of identifier, information into a system by a user in order to access, that system (e.g., a computer or a website). It generally, requires the user to enter two pieces of information, first a, user name and then a password., The basic syntax of w is:, w [options] [username1, username2, . . .], The square brackets indicated that the enclosed items, are optional. When used without any options, w sends to, standard output (which is by default the display screen) a, header line followed by a table that contains a line of data, for each user currently logged in., The header shows six items: the current time, how long, the system has been running (in minutes) since it was, booted up (i.e., started up), how many users are currently, logged on, and the system load averages, i.e., the average, number of processes active, during the last one, five and, 15 minutes. A process is an executing(i.e., running), instance of a program., The main part of w's output consists of a table showing, eight items of information for each user currently logged, into the system. The eight columns are labeled USER,, TTY, FROM, LOGIN@, IDLE, JCPU, PCPU and WHAT., USER is the login name of the user. TTY (which now, stands for terminal type but originally stood for teletype), is the name of the console or terminal (i.e., combination, of monitor and keyboard) that the user logged into, which, can also be found by using the tty command. Every time, a user logs in across the network, a new tty is assigned, to that user., , independent logical consoles that run in separate login, sessions, but which are accessed from the same physical, console (i.e., the same keyboard and screen). That is,, each virtual console can have a different, or the same,, user logged into it. On a Red Hat system, seven virtual, consoles are configured and active by default., FROM is the remote host (i.e., the name of some other, computer), if any, that the user logged into. LOGIN@ is, the time at which the user logged in. IDLE is the number, of hours and minutes since the user last typed anything, at the keyboard., JCPU is the number of minutes accumulated by all, processes attached to the tty. It does not include past, background processes (i.e., low priority processes that, operate only in gaps between higher priority foreground, processes), but it does include currently running, background processes., PCPU is the time consumed by the current process,, named in the WHAT column. WHAT lists the name of the, current process along with any options and arguments(i.e.,, input files) used with the command that launched it., Among the more useful of w's few options is -h, which, tells it to omit the header header line from its output. The, -s option tells it to use the short format, which omits the, login time, JCPU and PCPU columns. The -l option creates, a long listing, which is the same as the default. The -V, option displays the version number of the currently installed, w program., By default, w reports on all users. However, it can be made, to report on only a specified set of users by providing those, usernames in a comma-separated list., w provides information similar to that which would be, provided by a combination of the uptime, who and ps -a, commands. uptime produces a single line of output that, is the same as w's header line. who shows who is currently, logged into the system. ps -a lists all processes with a tty, except session leaders (i.e., processes that created, sessions)., w can be useful, but there are some faults with the, information it provides, and thus its output should only be, considered approximate. In particular, the notion of, thecurrent process is unclear and there are some problems, detecting background processes, even though they usually, account for much of the load on the system. Also, the, CPU time is only an estimate; for example, if a user leaves, a background process running after logging out, the time, is credited to the person currently on that terminal., last command, Display information about the users who logged in and out, of the system. The output of last can be very large, so the, following output has been filtered (through head) to display, top 10 lines only:, , The consoles can be real or virtual. A feature of Linux, systems is the use of virtual consoles, which act as, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 93
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$ last | head, root tty1 Mon Jul 9 10:06 still logged in, root tty1 Mon Jul 9 10:06 - 10:06 (00:00), raghu pts/1 :0.0 Mon Jul 9 10:05 - 10:06 (00:00), raghu pts/0 :0.0 Mon Jul 9 09:34 still logged in, raghu tty7 :0 Mon Jul 9 09:19 still logged in, , /dev/sda2 209715196 196519248 13195948 94%/, media/Data, fdisk command, The fdisk is the tool for getting partition information, adding, and removing partitions.The fdisk tool requires super user, privileges. To list all the partitions of all the hard drives, available:, $ fdisk -l, , reboot system boot 2.6.38-13-generi Mon Jul 9 09:09 10:12 (01:02), , Disk /dev/sda: 320.1 GB, 320072933376 bytes, , raghu tty7 :0 Sun Jul 8 23:36 - 00:30 (00:54), , 255 heads, 63 sectors/track, 38913 cylinders, , reboot system boot 2.6.38-13-generi Sun Jul 8 23:36 00:30 (00:54), , Units = cylinders of 16065 * 512 = 8225280 bytes, , raghu tty7 :0 Sun Jul 8 21:07 - down (01:06), reboot system boot 2.6.38-13-generi Sun Jul 8 21:07 22:14 (01:07), A similar command is lastb that shows last bad login, attempts. But this command must be run as root otherwise, would get an error of permission denied, $ lastb, raghu tty2 Mon Jul 9 10:16 - 10:16 (00:00), UNKNOWN tty2 Mon Jul 9 10:15 - 10:15 (00:00), ubuntu tty8 :1 Mon Jul 2 10:23 - 10:23 (00:00), btmp begins Mon Jul 2 10:23:54 2012, du command, du command determines disk usage of a file. If the, argument given to it is a directory, then it will list disk, usage of all the files and directories recursively under that, directory:, $ du /etc/passwd, 4 /etc/passwd, , Sector size (logical/physical): 512 bytes / 512 bytes, I/O size (minimum/optimal): 512 bytes / 512 bytes, Disk identifier: 0x396f396f, Device Boot Start End Blocks Id System, /dev/sda1 1 2611 20971520 7 HPFS/NTFS, /dev/sda2 2611 28720 209715200 7 HPFS/NTFS, /dev/sda3 * 28720 38914 81882113 5 Extended, /dev/sda5 28720 33942 41943040 7 HPFS/NTFS, /dev/sda6 33942 34464 4194304 7 HPFS/NTFS, /dev/sda7 34464 35739 10240000 83 Linux, /dev/sda8 35739 36376 5120000 83 Linux, /dev/sda9 36376 36886 4096000 82 Linux swap / Solaris, /dev/sda10 36887 38276 11164672 83 Linux, /dev/sda11 38277 38914 5117952 83 Linux, fdisk is an interactive tool to edit the partition table. It, takes a device (hard disk) as an argument, whose partition, table needs to be edited., $ fdisk /dev/sda, , $ du hello/, 4 hello/orb.db/logs, , WARNING: DOS-compatible mode is deprecated. It's, strongly recommended to switch off the mode (command, 'c') and change display units to sectors (command 'u')., , 20 hello/orb.db, , Command (m for help): m, , 52 hello/HelloApp, , 108 hello/, , Command, , action, , df command, , a, , toggle a bootable flag, , df reports file system usage. For example:, , b, , edit bsd disk label, , c, , toggle the dos compatibility flag, , Filesystem 1K-blocks Used Available Use% Mounted on, , d, , delete a partition, , /dev/sda7 10079084 7372872 2194212 78% /, , l, , list known partition types, , none 1522384 768 1521616 1% /dev, , m, , print this menu, , $ df, , none 1529012 252 1528760 1% /dev/shm, , n, , add a new partition, , none 1529012 108 1528904 1% /var/run, , o, , create a new empty DOS partition table, , none 1529012 4 1529008 1% /var/lock, , p, , print the partition table, , /dev/sda8 5039616 3758824 1024792 79% /home, , q, , quit without saving changes, , 94, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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s, , create a new empty Sun disklabel, , t, , change a partition's system id, , u, , change display/entry units, , v, , verify the partition table, , w, , write table to disk and exit, , x, , extra functionality (experts only), , Pressing 'm' at the fdisk prompt prints out above help that, lists all the commands available for fdisk. A new, partition can be created with n and an existing partition, can be deleted with d command. When you are done editing, the partitions, press w to write the changes to the disk,, and finally, q to quit from fdisk (q dies not save changes)., netstat command, 'netstat' is the command used to check the network, statistics of the system. It will list the current network, connections, routing table information, interface, statistics, masquerade connections and a lot more, information., $ netstat | head, Active Internet connections (w/o servers), Proto Recv-Q Send-Q Local Address Foreign Address State, Active UNIX domain sockets (w/o servers), Proto RefCnt Flags Type State I-Node Path, unix 13 [ ] DGRAM 8498 /dev/log, unix 2 [ ] DGRAM 6824 @/org/kernel/udev/udevd, unix 3 [ ] STREAM CONNECTED 56738 /var/run/dbus/, system_bus_socket, unix 3 [ ] STREAM CONNECTED 56113, , All of the files on a system have permissions that allow or, prevent others from viewing, modifying or executing. If the, file is of type Directory then it restricts different actions, than files and device nodes. The super user "root" has the, ability to access any file on the system. Each file has, access restrictions with permissions, user restrictions with, owner/group association. Permissions are referred to as, bits., If the owner read & execute bit are on, then the permissions, are:, There are three types of access restrictions:, Permission, , (view), , r or 4, , write, , (edit), , w or 2, , execute, , passwd command, Change your password with 'passwd' command., shutdown -h now, Finally shut down your system using this command., Understanding and using file permissions, In Linux and Unix, everything is a file. Directories are files,, files are files and devices are files. Devices are, usually referred to as a node; however, they are still files., , (execute), , x or 1, , There are also three types of user restrictions:, User, , ls output, , owner, , -rwx------, , group, , ----rwx---, , other, , -------rwx, , The restriction type scope is not inheritable:, the file owner will be unaffected by restrictions, set for his group or everybody else., Folder/Directory Permissions, Directories have directory permissions. The directory, permissions restrict different actions than with files or device, nodes., Permission, , Action, , chmod option, , Read, , (view contents,, i.e. ls command), , r or 4, , Write, , (create or remove, files from dir), , w or 2, , execute, , (cd into directory), , x or 1, , history command, This command shows the commands you have entered, on your terminal so far., , Chmod option, , read, , unix 3 [ ] STREAM CONNECTED 29138, unix 3 [ ] STREAM CONNECTED 29137, , Action, , 1. read restricts or allows viewing the directories contents,, i.e. ls command, 2. write restricts or allows creating new files or deleting, files in the directory. (Caution: write access for a, directory allows deleting of files in the directory even if, the user does not have write permissions for the file!), 3. execute restricts or allows changing into the directory,, i.e. cd command, Folders (directories) must have 'execute' permissions set, (x or 1), or folders (directories) will NOT FUNCTION as, folders (directories) and WILL DISAPPEAR from view in, the file browser (Nautilus)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 95
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Permissions in Action, , Here are a few examples of chmod usage with letters (try, these out on your system)., , $ ls -l /etc/hosts, -rw-r--r-- 1 root root 288 2005-11-13 19:24 /etc/hosts, Using the example above we have the file "/etc/hosts", which is owned by the user root and belongs to the root, group., The permissions from the above /etc/hosts ls output, -rw-r--r-owner = Read & Write (rw-), group = Read (r--), , First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, total 0, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, , other = Read (r--), , Add owner execute bit:, , Changing permissions, The command to use when modifying permissions is, chmod. There are two ways to modify permissions, with, numbers or with letters. Using letters is easier to, understand for most people. When modifying permissions, be careful not to create security problems. Some files are, configured to have very restrictive permissions to prevent, unauthorized access. For example, the /etc/shadow file, (file that stores all local user passwords) does not have, permissions for regular users to read or otherwise access., $ ls -l /etc/shadow, , $ chmod u+x file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod o+wx file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, , -rw-r----- 1 root shadow 869 2005-11-08 13:16 /etc/shadow, , $ chmod g-r file3, , Permissions:, , $ ls -l file3, , owner = Read & Write (rw-), , Add read, write and execute to everyone:, , group = Read (r--), , $ chmod ugo+rwx file4, , other = None (---), , $ ls -l file4, , Ownership:, owner = root, , -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, , group = shadow, , $, chmod with Numbers, , chmod with Letters, Usage: chmod {options} filename, Options, , 96, , -rw----r-- 1 user user 0 Nov 19 20:13 file3, , Definition, , U, , owner, , G, , group, , O, , other, , A, , all (same as ugo), , X, , execute, , W, , write, , R, , read, , +, , add permission, , -, , remove permission, , =, , set permission, , Usage: chmod {options} filename, Options, , Definition, , #--, , owner, , -#-, , group, , --#, , other, , 1, , execute, , 2, , write, , 4, , read, , Owner, Group and Other is represented by three numbers., To get the value for the options determine the type of, access needed for the file then add., For example if need a file that has -rw-rw-rwx permissions, will use the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Owner, read & write, , Group, read & write, , 4+2=6, , Other, read, write & execute, , 4+2=6, , 4+2+1=7, , Another example if you want a file that has --w-r-x--x, permissions you will use the following:, , write, 2, , Group, read & execute, 4+1 = 5, , Other, execute, 1, , $ chmod 251 filename, Here are a few examples of chmod usage with numbers, (try these out on your system)., First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, Add owner execute bit:, $ chmod 744 file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod 647 file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, $ chmod 604 file3, $ ls -l file3, -rw----r-- 1 user user 0 Nov 19 20:13 file3, Add read, write and execute to everyone:, $ chmod 777 file4, $ ls -l file4, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, chmod with sudo, , -rw-r--r-- 1 root root 550 2005-11-13 19:45 /usr/local/bin/, somefile, $ sudo chmod o+x /usr/local/bin/somefile, $ ls -l /usr/local/bin/somefile, -rw-r--r-x 1 root root 550 2005-11-13 19:45 /usr/local/, bin/somefile, $, Recursive permission changes, To change the permissions of multiple files and directories, with one command. Please note the warning in the chmod, with sudo section and the Warning with Recursive chmod, section., Recursive chmod with -R and sudo, To change all the permissions of each file and folder under, a specified directory at once, use sudo chmod with -R, $ sudo chmod 777 -R /path/to/someDirectory, , total 0, , $, , $ ls -l /usr/local/bin/somefile, , $, , $ chmod 667 filename, , Owner, , Please be careful when using sudo!), , $ ls -l, total 3, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file2, Recursive chmod using find, pipemill, and sudo, To assign reasonably secure permissions to files and, folders/directories, it's common to give files a permission, of 644, and directories a 755 permission, since chmod -R, assigns to both. Use sudo, the find command, and a, pipemill to chmod as in the following examples., To change permission of only files under a specified, directory., $ sudo find /path/to/someDirectory -type f -print0 | xargs, -0 sudo chmod 644, user@host:/home/user$ ls -l, total 3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, To change permission of only directories under a specified, directory (including that directory):, $ sudo find /path/to/someDirectory -type d -print0 | xargs, -0 sudo chmod 755, $ ls -l, , total 3, Changing permissions on files that do not have ownership, of: (Note that changing permissions the wrong way on the, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, wrong files can quickly mess up the system a great deal!, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 97
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drwxr-xr-x 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, Warning with Recursive chmod, WARNING: Although it's been said, it's worth mentioning, in context of a gotcha typo. Please note, Recursively, deleting or chown-ing files are extremely dangerous. You, will not be the first, nor the last, person to add one too, many spaces into the command. This example will hose, your system:, $ sudo chmod -R / home/john/Desktop/tempfiles, Note the space between the first / and home.You have, been warned., Changing the file owner and group, A file's owner can be changed using the chown command., For example, to change the foobar file's owner to tux:, $ sudo chown tux foobar, To change the foobar file's group to penguins, you could, use either chgrp or chown with special syntax:, $ sudo chgrp penguins foobar, $ sudo chown :penguins foobar, Finally, to change the foobar file's owner to tux and the, group to penguins with a single command, the syntax, would be:, $ sudo chown tux:penguins foobar, Note that, by default, you must use sudo to change a, file's owner or group., Difference between chown and chgrp, 1) Chown command is used to change ownership as well, as group name associated to different one, where as, chgrp can change only group associated to it., 2) Many people say that regular user only able to use, chgrp to change the group if the user belongs to them., But it's not true a user can use chown and chgrp, irrespective to change group to one of their group, because chown is located in /bin folder so every can, use it with some limited access., umask - Set default permissions, The umask command controls the default permissions, given to a file when it is created., It uses octal notation to express a mask of bits to be, removed from a file's mode attributes., [me@linuxbox ~]$ rm -f foo.txt, [me@linuxbox ~]$ umask, 0002, [me@linuxbox ~]$ > foo.txt, [me@linuxbox ~]$ ls -l foo.txt, -rw-rw-r-- 1 me me 0 2008-03-06 14:53 foo.txt, , we ran the umask command without an argument to see, the current value. It responded with the value 0002 (the, value 0022 is another common default value), which is the, octal representation of our mask. We next create a new, instance of the file foo.txt and observe its permissions., We can see that both the owner and group both get read, and write permission, while everyone else only gets read, permission. The reason that world does not have write, permission is because of the value of the mask., $ rm foo.txt, $ umask 0000, $ > foo.txt, $ ls -l foo.txt, -rw-rw-rw- 1 me me 0 2008-03-06 14:58 foo.txt, When we set the mask to 0000 (effectively turning it off),, we see that the file is now, world writable. To understand how this works, we have to, look at octal numbers again., If we take the mask and expand it into binary, then compare, it to the attributes., Original file mode, , --- rw- rw- rw-, , Mask, , 000 000 000 010, , Result, , --- rw- rw- r--, , Ignore for the moment the leading zeros (we'll get to those, in a minute) and observe that, where the 1 appears in our mask, an attribute was removedin this case, the the world, write permission. That's what the mask does. Everywhere, a 1 appears in the binary value, of the mask, an attribute is unset. If we look at a mask, value of 0022, we can see what it does:, Original file mode, , --- rw- rw- rw-, , Mask 000 000 010 010, Result, , --- rw- r-- r--, , Again, where a 1 appears in the binary value, the, corresponding attribute is unset. Play with some values, (try some sevens) to get used to how this works. When, you're done, remember to clean up:, $ rm foo.txt; umask 0002, The Tar command, The tar (i.e., tape archive) command is used to convert a, group of files into an archive., An archive is a single file that contains any number of, individual files plus information to allow them to be, restored to their original form by one or more extraction, programs. Archives are convenient for storing files as well, as for for transmitting data and distributing programs., Moreover, they are very easy to work with, often much, more so than dealing with large numbers of individual files., , We first removed any old copy of foo.txt to make sure we, were starting fresh. Next,, 98, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Although tar was originally designed for backups on, magnetic tape, it can now be used to create archive files, anywhere on a file system. Archives that have been created, with tar are commonly referred to as tar balls., Unlike some other archiving programs, and consistent with, the Unix philosophy that each individual program should, be designed to do only one thing but do it well, tar does, not perform compression. However, it is very easy to, compress archives created with tar by using specialized, compression utilities., tar's basic syntax is, tar option(s) archive_name file_name(s), tar has numerous options, many of which are not, frequently used. Unlike many commands, tar requires the, use of at least one option, and usually two or more are, necessary., tar files are created by using both the -c and -f options., The former instructs tar to create an archive and the latter, indicates that the next argument (i.e., piece of input data, in a command) will be the name of the new archive file., Thus, for example, the following would create an archive, file called file.tar from the three files namedfile1, file2 and, file3 that are located in the current directory (i.e., the, directory in which the user is currently working):, tar -cf file.tar file1 file2 file3, It is not absolutely necessary that the new file have the, .tar extension; however, the use of this extension can be, is very convenient because it allows the type of file to be, visually identified. It is necessary, however, that the -f option, be the final option in a sequence of contiguous, singleletter options; otherwise, the system will become confused, as to the desired name for the new file and will use the, next option in the sequence as the name., The -v (i.e., verbose) option is commonly used together, with the -c and -f options in order to display a list of the, files that are included in the archive. In such case, the, above example would become, tar -cvf file.tar file1 file2 file3, tar can also be used to make archives from the contents, of one or more directories. The result is recursive; that is,, it includes all objects (e.g., directories and files) within, each level of directories. For example, the contents of two, directories named dir1 and dir2 could be archived into a, file named dir.tar with the following:, tar -cvf dir.tar dir1 dir2, It is often convenient to use tar with a wildcard (i.e., a, character which can represent some specific class of, characters or sequence of characters). The following, example uses the star wildcard (i.e., an asterisk), which, represents any character or sequence of characters, to, create an archive of every object in the current directory:, tar -cf *, By default, tar creates an archive of copies of the original, files and/or directories, and the originals are retained., , However, they can be removed when using tar by adding, the --remove-files option., As it has no compression and decompression capabilities, of its own, tar is commonly used in combination with an, external compression utility. A very handy feature of the, GNU version (which is standard on Linux) is the availability, of options that will cause standard compression programs, to compress a new archive file as soon as it has been, created. They are -j (for bzip2), -z (for gzip) and -Z (for, compress). Thus, for example, the following would create, an archive named files.tar.bz2 of the files file4, file5 and, file6 that is compressed using bzip2:, tar -cvjf files.tar.bz2 file4 file5 file6, tar can also be used for unpacking tar files. However, before, doing this, there are several steps that should be taken., One is to confirm that sufficient space is available on the, hard disk drive (HDD). Another is to move to an empty, directory (which usually involves creating one with an, appropriate name) to prevent the reconstituted files from, cluttering up the current directory and overwriting any files, or directories with same names that are in it. In addition, if, the archive has been compressed, it must first be, decompressed using the appropriate decompression, program (which can usually be determined by the filename, extension)., In order to unpack a tar file, the -x (for extract) and -f, options are required. It is also common to add the -v option, to provide a running listing of the files being unpacked., Thus, for example, to unpack the archive file.tar created in, a previous example the following would be used:, tar -xvf file.tar, Just as options are available to allow three compression, programs to automatically compress newly created tar, files, the same options can be used to have the, compression programs automatically decompress tar files, prior to extraction. Thus, for instance, the following would, decompress and extract the contents of the compressed, archive files.tar.bz2 that was created in an above example:, tar -xjvf files.tar.bz2, Files can be added to an existing archive using the -r, option. As is always the case with tar, it is also necessary, to use the -f option to indicate that the followingstring (i.e.,, sequence of characters) is the name of the archive. For, example, the following would append a file named file7 to, file.tar:, tar -rf file.tar file7, The --delete option allows specified files to be completely, removed from a tar file (except when the tar file is on, magnetic tape). However, this is different from an, extraction, as copies of the removed files are not made, and placed in the current directory. Thus, for example, the, files file1 and file2 can be removed from file.tar with the, following:, tar -f file.tar --delete file1 file2, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 99
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The -t option tells tar to list the contents of an, uncompressed archive without performing an extraction., Thus, the following would list the contents of file.tar:, tar -tf file.tar, Input, output and error redirection in linux, Input/output redirection means the text that is showing on, the screen while you are running any command(program)in, the shell, that information can be redirect elsewhere and, even it can store this output in a file or can be print directly., This function called Redirection, and can also redirect the, input of program., In Linux systems everything consider as a file., A file descriptor is number that is associated with every, file, When run a program in shell ( i.e when execute a command, ) on the back end Linux access 3 special files., Standard input - 0 file descriptor( example = mouse,), Standard output - 1 file descriptor( example = Screen), Standard error output - 2 file descriptor(example=Screen), So it can redirect these files to other files. If user redirect, standard output (Descriptor = 1) to the printer, instead of, showing these outputs on the screen and the computer, start getting print on paper., Output Redirection, Output Redirection is most commonly used, when execute, a command it's normally appears on the terminal . If extract, any tar file you will notice all the output scrolls down rapidly., And can redirect this output in a file for inspecting the, output or can send anybody via email. This is called Output, Redirection. Using this operator '>' in shell can redirect, the output in a file., Example :, $ ls > output.txt, $ cat output.txt, bin, boot, , root, sbin, selinux, srv, sys, tmp, usr, var, $, If output.txt file is already exit then '>' operator, will overwrite the file for append more output, into output.txt use '>>' instead of '>'., Input Redirection, You can redirect your input by using '<' operator. Cannot, run input redirection on all programs or commands. And, can use only with that programs or commands that accept, Input from keyboard., Example : user going to send an email and already have, Template of that email. and can put template in the email, body using input redirect., $ mail ali < mail_template.txt, above command launch email program with, mail_template.txt contents., Now due to advancement in GUI, and also lots of good, email clients, method is rarely used., Error Redirection, Error Redirection is very helpful when in trouble. In this, case user trying to open a file that is not readable for my, user will get permission denied errors. it will redirect these, error into error.txt file., Example :, $ cat ali.txt 2> /home/H.Ali/error.txt, $ cat /home/H.Ali/error.txt, cat: ali.txt: Permission denied, , etc, , In the above command 2 is descriptor of error redirection, file by typing '2>' you are saying redirect any kind of error, to the file error.txt, , home, , Pipes ' | ' in Linux, , lib, , Linux pipes allow us connect output stream of 'command, a' to input stream of 'command b'. here in my case i will, pipe cat commands output into less as input., , dev, , lib64, lost+found, media, mnt, opt, output.txt, proc, 100, , Example : cat /var/log/messages | less, we can also use pipe for searching strings specially from, large text files., cat /var/log/messages | grep kernal | less, grep is a line searcher it will search lines for specific piece, of text., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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above command will shearch a keywork 'kernel' with grep, and then pipe it again to less., Pipes in linux, A pipe is a form of redirection that is used in Linux and, other Unix-like operating systems to send the output of, one program to another program for further processing., Redirection is the transferring of standard output to some, other destination, such as another program, a file or a, printer, instead of the display monitor (which is its default, destination). Standard output, sometimes abbreviated, stdout, is the destination of the output from command line, (i.e., all-text mode) programs in Unix-like operating, systems., Pipes are used to create what can be visualized as a, pipeline of commands, which is a temporary direct, connection between two or more simple programs. This, connection makes possible the performance of some highly, specialized task that none of the constituent programs, could perform by themselves. A command is merely an, instruction provided by a user telling a computer to do, something, such as launch a program. The command line, programs that do the further processing are referred to as, filters., This direct connection between programs allows them to, operate simultaneously and permits data to be transferred, between them continuously rather than having to pass it, through temporary text files or through the display screen, and having to wait for one program to be completed before, the next program begins., Examples, A pipe is designated in commands by the vertical bar, character, which is located on the same key as the, backslash on U.S. keyboards. The general syntax for, pipes is:, command_1 | command_2 [| command_3 . . . ], This chain can continue for any number of commands or, programs., A very simple example of the benefits of piping is provided, by the dmesg command, which repeats the startup, messages that scroll through the console(i.e., the all-text,, full-screen display) while Linux is booting (i.e., starting, up). dmesg by itself produces far too many lines of output, to fit into a single screen; thus, its output scrolls down the, screen at high speed and only the final screenful of, messages is easily readable. However, by piping the output, of dmesg to the filter less, the startup messages can, conveniently be viewed one screenful at a time, i.e.,, dmesg | less, , The same result could be achieved by first redirecting the, output of dmesg to a temporary file and then displaying, the contents of that file on the monitor. For example, the, following set of two commands uses the output redirection, operator (designated by a rightward facing angle bracket), to first send the output of dmesg to a text file called tempfile1, (which will be created by the output redirection operator if, it does not already exist), and then it uses another output, redirection operator to transfer the output of tempfile1 to, the display screen:, dmesg > tempfile1, tempfile1 > less, However, redirection to a file as an intermediate step is, clearly less efficient, both because two separate, commands are required and because the second, command must await the completion of the first command, before it can begin., The use of two pipes to chain three commands together, could make the above example even more convenient for, some situations. For example, the output of dmesg could, first be piped to the sort filter to arrange it into alphabetic, order before piping it to less:, dmesg | sort -f | less, The -f option tells sort to disregard case (i.e., whether, letters are lower case or upper case) while sorting., Likewise, the output of the ls command (which is used to, list the contents of a directory) is commonly piped to the, the less (or more) command to make the output easier to, read, i.e.,, ls -al | less, or, ls -al | more, ls reports the contents of the current directory (i.e., the, directory in which the user is currently working) in the, absence of any arguments (i.e., input data in the form of, the names of files or directories). The -l option tells ls to, provide detailed information about each item, and the aoption tells ls to include all files, including hidden files, (i.e., files that are normally not visible to users). Because, ls returns its output in alphabetic order by default, it is not, necessary to pipe its output to the sort command (unless, it is desired to perform a different type of sorting, such as, reverse sorting, in which case sort's -r option would be, used)., This could just as easily be done for any other directory., For example, the following would list the contents of the /, bin directory (which contains user commands) in a, convenient paged format:, , less allows the output of dmesg to be moved forward one, ls -al /bin | less, screenful at a time by pressing the SPACE bar and back, The following example employs a pipe to combine the ls, one screenful at a time by pressing the b key. The command, and the wc (i.e., word count) commands in order to show, can be terminated by pressing the q key. (The more, how many filesystem objects (i.e., files, directories and, command could have been used here instead of less;, links) are in the current directory:, however, less is newer than more and has additional, functions, including the ability to return to previous pages, ls | wc -l, of the output.), 101, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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ls lists each object, one per line, and this list is then piped, to wc, which, when used with its -l option, counts the, number of lines and writes the result to standard output, (which, as usual, is by default the display screen)., The output from a pipeline of commands can be just as, easily redirected to a file (where it is written to that file) or, a printer (where it is printed on paper). In the case of the, above example, the output could be redirected to a file, named, for instance, count.txt:, ls | wc -l > count.txt, The output redirection operator will create count.txt if it, does not exist or overwrite it if it already exists. (The file, does not, of course, require the .txt extension, and it could, have just as easily been named count, lines or anything, else.), The following is a slightly more complex example of, combining a pipe with redirection to a file:, echo -e "orange \npeach \ncherry" | sort > fruit, The echo command tells the computer to send the text, that follows it to standard output, and its -e option tells the, computer to interpret each \nas the newline symbol (which, is used to start a new line in the output). The pipe redirects, the output from echo -e to the sort command, which, arranges it alphabetically, after which it is redirected by, the output redirection operator to the file fruit., As a final example, and to further illustrate the great power, and flexibility that pipes can provide, the following uses, three pipes to search the contents of all of the files in, current directory and display the total number of lines in, them that contain the string Linux but not the stringUNIX:, cat * | grep "Linux" | grep -v "UNIX" | wc -l, In the first of the four segments of this pipeline, the cat, command, which is used to read and concatenate (i.e.,, string together) the contents of files, concatenates the, contents of all of the files in the current directory. The, asterisk is a wildcard that represents all items in a specified, directory, and in this case it serves as an argument to cat, to represent all objects in the current directory., The first pipe sends the output of cat to the grep, command, which is used to search text. The Linux, argument tells grep to return only those lines that contain, the string Linux. The second pipe sends these lines to, another instance of grep, which, in turn, with its -v option,, eliminates those lines that contain the string UNIX., Finally, the third pipe sends this output to wc -l, which, counts the number of lines and writes the result to the, display screen., Find hardware devices in Ubuntu Linux with lshw, There are a variety of ways to find out what kind of, hardware running in linux, but one of the easiest ways, that gives a large amounts of valuable data is to use lshw, (Hardware Lister). And lshw is installed by default., Testing of lshw command as shown below…, $ sudo lshw, 102, , Installing, lshw is available on most package management systems., If use APT (Debian-based distros: Ubuntu, Linux Mint, and, others), run the following command in terminal:, $ sudo apt-get install lshw, If use Yum (Red Hat, Fedora, CentOS, Yellow Dog Linux,, etc), run the following command in terminal:, $ sudo yum install lshw, If these instructions don't match your package manager,, look for specific instructions on the lshw site to get it, installed on your system., Using lshw, If you just run lshw by itself on the command line, your, screen will be flooded with large amounts of text., Fortunately, it is very easy to get lshw to give you output, that meets your needs., Shorter output, If you just quickly want to quickly find the chipset version, of a piece of hardware is, you can run the following to, provide a very short output that should give you what you, need:, $ sudo lshw -short, For example, here is a sample when I run this on my Dell, Studio 17 laptop (Note: I've removed a large portion of the, output to make this fit):, $ sudo lshw -short, Device class, , Description, , system, , Studio 1735, , bus, , 0H275K, , memory, , 64KiB BIOS, , processor, , Intel(R) Core(TM)2 Duo CPU, T8100 @ 2.10GHz, , memory, , 32KiB L1 cache, , memory, , 3MiB L2 cache, , memory, , 4GiB System Memory, , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , display, , Mobility Radeon HD 3650, , multimedia, , RV635 Audio device [Radeon HD, 3600 Series], , multimedia, , 82801H (ICH8 Family) HD, Audio Controller, , eth1 network, , BCM4322 802.11a/b/g/n, Wireless LAN Controller, , eth0 network, , NetLink BCM5784M Gigabit, Ethernet PCIe, , /dev/sda disk, 250GB WDC WD2500BEVS-7, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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This of course leaves out a lot of detail. Maybe we just, need to store the data somewhere so it's easier to work, with., Storing output to a file, If you'd like to put all the lshw output into a file, you can do, so easily from the terminal with output redirection., $ sudo lshw > hardware.txt, This will run the lshw command and put all the output into, a file in the current directory called hardware.txt. Note, that this will replace any file in the current directory called, hardware.txt. Make sure that you either backup the file,, give the output file a unique name, or are prepared to lose, that original file's information., Now you can open the hardware.txt file with your favorite, editor and look through the informations., , Creating HTML or XML Output, lshw has the ability to format its output in either HTML or, XML. This can be very helpful if you want to post your, hardware specs somewhere online to be viewed or to send, the data to a storage system., To create HTML output, simply give lshw the -html, option:, $ sudo lshw -html > hardware.html, This will format the output into a HTML document and, save the output in a file called hardware.html., Creating XML is done with the -xml option:, $ sudo lshw -xml > hardware.xml, Like before, this will output the document in XML format, and save it to hardware.xml., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 103
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Date command examples to display and set, system date time, Date command is helpful to display date in several formats., It also allows you to set systems date and time., Here few examples on how to use date command with, practical examples., When execute date command without any option, it will, display the current date and time as shown below., $ date, Mon May 20 22:02:24 PDT 2013, 1. Display Date from a String Value using -date, Option, If you have a static date or time value in a string, you can, use -d or -date option to convert the input string into date, format as shown below., Please note that this doesn't use the current date and, time value. Instead is uses the date and time value that, you pass as string., The following examples takes an input date only string,, and displays the output in date format. If you don't specify, time, it uses 00:00:00 for time., $ date --date="12/2/2014", Tue Dec 2 00:00:00 PST 2014, , 3. Get Relative Date Using -date option, You can also use date command to get a future date using, relative values., For example, the following examples gets date of next, Monday., $ date --date="next mon", Mon May 27 00:00:00 PDT 2013, If string=@is given to date command, then date command, convert seconds since the epoch (1970-01-01 UTC) to a, date., It displays date in which 5 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@5, Wed Dec 31 16:00:05 PST 1969, It displays date in which 10 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@10, Wed Dec 31 16:00:10 PST 1969, It displays date in which 1 minute (i.e. 60 seconds) is, elapsed since epoch 1970-01-01 UTC:, $ date --date=@60, Wed Dec 31 16:01:00 PST 1969, , $ date --date="2 Feb 2014", , 4. Display past date, , Sun Feb 2 00:00:00 PST 2014, , You can display a past date using the -date command., Few possibilities are shown below., , $ date --date="Feb 2 2014", Sun Feb 2 00:00:00 PST 2014, The following example takes an input date and time string,, and displays the output in date format., , $ date --date='3 seconds ago', Mon May 20 21:59:20 PDT 2013, $ date --date="1 day ago", , $ date --date="Feb 2 2014 13:12:10", , Sun May 19 21:59:36 PDT 2013, , Sun Feb 2 13:12:10 PST 2014, , $ date --date="yesterday", , 2. Read Date Patterns from a file using -file option, This is similar to the -d or -date option that we discussed, above. But, you can do it for multiple date strings. If you, have a file that contains various static date strings, you, can use -f or -file option as shown below., In this example, we can see that datefile contained 2 date, strings. Each line of datefile is parsed by date command, and date is outputted for each line., $ cat datefile, , $ date --date="1 month ago", Sat Apr 20 21:59:58 PDT 2013, $ date --date="1 year ago", Sun May 20 22:00:09 PDT 2012, 5. Set Date and Time using -set option, You can set date and time of your system using -s or -set, option as shown below.., , Sept 9 1986, Aug 23 1987, , In this example, initially it displayed the time as 20:09:31., We then used date command to change it to 21:00:00., , $ date --file=datefile, Tue Sep 9 00:00:00 PDT 1986, Sun Aug 23 00:00:00 PDT 1987, , 104, , Sun May 19 22:00:26 PDT 2013, , $ date, Sun May 20 20:09:31 PDT 2013, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ date -s "Sun May 20 21:00:00 PDT 2013", Sun May 20 21:00:00 PDT 2013, $ date, , The timestamp of datefile is changed using touch command. This was done few seconds after the above date, command's output., $ touch datefile, , Sun May 20 21:00:05 PDT 2013, 6. Display Universal Time using -u option, You can display date in UTC format using -u, or -utc, or universal option as shown below., $ date, Mon May 20 22:07:53 PDT 2013, $ date -u, Tue May 21 05:07:55 UTC 2013, , The current time after the above touch command is, 20:26:12, $ date, Sun May 20 20:26:12 PDT 2013, Finally, use the date command -r option to display the, last modified timestamp of a file as shown below. In this, example, it displays last modified time of datefile as, 20:25:57. It is somewhere between 20:25:48 and 20:26:12, (which is when we execute the above touch command to, modify the timestamp)., , 7. Display Last Modification Time using -r option, , $ date -r datefile, , In this example, the current time is 20:25:48, , Sun May 20 20:25:57 PDT 2013, , $ date, , 8. Various Date command formats, , Sun May 20 20:25:48 PDT 2013, , You can use formatting option to display date command, in various formats using the following syntax:, $ date +%<format-option>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 105
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Command, , Description, , • apropos whatis, , Show commands pertinent to string. See, also threadsafe, , • man -t ascii | ps2pdf - > ascii.pdf, , make a pdf of a manual page, , which command, , Show full path name of command, , time command, , See how long a command takes, Start stopwatch. Ctrl-d to stop. See also, sw, , • time cat, dir navigation, • cd -, , Go to previous directory, , • cd, , Go to $HOME directory, , (cd dir && command), , Go to dir, execute command and return to, current dir, Put current dir on stack so you can popd, back to it, , • pushd ., file searching, • alias l='ls -l --color=auto', , quick dir listing. See also l, , • ls -lrt, , List files by date. See also newest and, find_mm_yyyy, , • ls /usr/bin | pr -T9 -W$COLUMNS, , Print in 9 columns to width of terminal, , find -name '*.[ch]' | xargs grep -E 'expr', , Search 'expr' in this dir and below. See, also findrepo, , find -type f -print0 | xargs -r0 grep -F 'example', , Search all regular files for 'example' in, this dir and below, , find -maxdepth 1 -type f | xargs grep -F, 'example', , Search all regular files for 'example' in, this dir, , find -maxdepth 1 -type d | while read dir; do, echo $dir; echo cmd2; done, , Process each item with multiple, commands (in while loop), , • find -type f ! -perm -444, , Find files not readable by all (useful for, web site), , • find -type d ! -perm -111, , Find dirs not accessible by all (useful for, web site), , • locate -r 'file[^/]*\.txt', , Search cached index for names. This re is, like glob *file*.txt, , • look reference, , Quickly search (sorted) dictionary for, prefix, , • grep --color reference /usr/share/dict/words, , Highlight occurances of regular, expression in dictionary, , archives and compression, gpg -c file, , Encrypt file, , gpg file.gpg, , Decrypt file, , tar -c dir/ | bzip2 > dir.tar.bz2, , Make compressed archive of dir/, , bzip2 -dc dir.tar.bz2 | tar -x, , Extract archive (use gzip instead of bzip2, for tar.gz files), , tar -c dir/ | gzip | gpg -c | ssh user@remote 'dd Make encrypted archive of dir/ on remote, of=dir.tar.gz.gpg', machine, , 106, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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set operations (Note you can export LANG=C for speed. Also these assume no, duplicate lines within a file), sort file1 file2 | uniq, , Union of unsorted files, , sort file1 file2 | uniq -d, , Intersection of unsorted files, , sort file1 file1 file2 | uniq -u, , Difference of unsorted files, , sort file1 file2 | uniq -u, , Symmetric Difference of unsorted files, , join -t'\0' -a1 -a2 file1 file2, , Union of sorted files, , join -t'\0' file1 file2, , Intersection of sorted files, , join -t'\0' -v2 file1 file2, , Difference of sorted files, , join -t'\0' -v1 -v2 file1 file2, , Symmetric Difference of sorted files, , math, • echo '(1 + sqrt(5))/2' | bc -l, , Quick math (Calculate φ). See also bc, , • seq -f '4/%g' 1 2 99999 | paste -sd-+ | bc -l, , Calculate π the unix way, , •, , echo 'pad=20; min=64;, (100*10^6)/((pad+min)*8)' | bc, , More complex (int) e.g. This shows max, FastE packet rate, , •, , echo 'pad=20; min=64; print, (100E6)/((pad+min)*8)' | python, , Python handles scientific notation, , •, , echo 'pad=20; plot [64:1518], (100*10**6)/((pad+x)*8)' | gnuplot -persist, , Plot FastE packet rate vs packet size, , • echo 'obase=16; ibase=10; 64206' | bc, , Base conversion (decimal to, hexadecimal), , • echo $((0x2dec)), , Base conversion (hex to dec) ((shell, arithmetic expansion)), , • units -t '100m/9.58s' 'miles/hour', , Unit conversion (metric to imperial), , • units -t '500GB' 'GiB', , Unit conversion (SI to IEC prefixes), , • units -t '1 googol', , Definition lookup, , • seq 100 | paste -s -d+ | bc, , Add a column of numbers. See also add, and funcpy, , calendar, • cal -3, , Display a calendar, , • cal 9 1752, , Display a calendar for a particular month, year, , • date -d fri, , What date is it this friday. See also day, , •, , [ $(date -d '12:00 today +1 day' +%d) = '01' ], || exit, , exit a script unless it's the last day of the, month, , • date --date='25 Dec' +%A, , What day does xmas fall on, this year, , • date --date='@2147483647', , Convert seconds since the epoch (197001-01 UTC) to date, , • TZ='America/Los_Angeles' date, , What time is it on west coast of US (use, tzselect to find TZ), , •, , date --date='TZ="America/Los_Angeles" 09:00, next Fri', , What's the local time for 9AM next Friday, on west coast US, , locales, • printf "%'d\n" 1234, , Print number with thousands grouping, appropriate to locale, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 109
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.29, , MS WORD 2010 THEORY, Objectives : At the end of this lesson you shall be able to, • state what is MS Office, • brief what is MS Word and starting steps, • explain various screen blocks of MS Word, • explain procedures to create, save, print a documentl., Microsoft office is a application software package, introduced by Microsoft Corporation. MS Office consists, of the following popular packages :, , The Ribbon tab of Word has eight major parts viz. File,, Home, Insert, Page Layout, References, Mailings,, Review and View., , •, , Microsoft Word, , •, , Microsoft Excel, , •, , Microsoft Powerpoint, , •, , Microsoft Access, , •, , Microsoft Outlook, , File tab of the ribbon is useful to create a new file, a, blank or a template page as required. Ctrl + N always, create a new blank document in Office Package. The, documents so created can be saved as default word, document or given compatible format. Furthermore,, permission for accessing a documents can be fixed,, share a document on a network, even manage a, document to be compatible with previous and external, versions. Print option makes the document to get a hard, copy or a pdf format according to the installed printer, features. Recently opened files can also be viewed to, find it easy to work again. Help on word is there in the, same tab., , Word 2010, It is a word processor package that helps to create and, edit a document. It is the most known word processor of, nowadays. It makes professional looking documents by, providing a comprehensive set of tools for creating and, formatting a document, memos, letters, reports,, brochures, business documents and even internet web, pages., , Fig. 2 Home Tab, , Fig 2, , Starting Word, , Fig 1 - Default page layout, , Copa 1182902, , Click on the Start > (windows Logo) All programmes >, Microsoft office > Microsoft Word. MS Word opens along, with a default blank document with default settings page, layout., , Home tab has clipboard options including cut, copy, paste, and paste special. The Font block has all the options of, setting fonts, size, superscript, subscript, bold, italic,, underline, strikethrough, font colors, etc., , Fig 1, , Fig 3 - Paragraph Group, , Unlike previous version, MS Office 2010 has a common, set of features for all the components. It makes it easy, to understand and common utilities to remain available, on all the packages of MS Office including Word, Excel,, PowerPoint, Access, etc. Many features are redesigned, so as enabling the diverted users of other packaged can, afford with. These enhancements and utilities in Word, 2010 are described as below., , Copa 1182903, , Copa 1182901, , Fig 3, , Paragraph group creates the formatting paragraphs with, alignments left, right, center, justify and indentations, para, and line spacing. Line and page breaks allows to create, pagination options and exceptions of formatting., , Copyright @ NIMI Not to be Republished, , 113
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Fig 4 - Styles and Editing Group, , Symbols group inserts symbols of equations like math, equations or symbols like currency, math symbols, etc., Copa 1182904, , Fig 4, , Fig 8 - Themes and Page Setup Group, , Fig 8, , Copa 1182905, , Fig 5, , Page group makes cover pages, blank pages insertion, and page breaks. Tables group helps to insert a table in a, text document with ready specified row-column set or a, customized table format. Illustration group inserts pictures, from external sources, cliparts, shapes, smart art, charts, of data, even screenshot into the text document., Fig 6 - Links and Header/Footer Groups, , Page Layout tab has five major groups. Themes block, creates predefined template setup using themes on, documents. Even new themes customized can be, created and saved for future use., Page setup group has features on margin around, page, orientation i.e. vertical or horizontal, paper size, columns, to display, breaks, line numbers and hyphenation., Fig 9 - Page Background and Paragraph Group, Fig 9, Copa 1182909, , The Insert tab has 7 groups. Fig 5 - Pages, Tables and, Illustrations blocks (Fig 5), , Copa1182908, , The Styles group allows preformatted text styles like, Heading styles, Paragraph styles, Subtitles, etc. Custom, styles can also be stored with altered specifications. The, Editing group used to select specific area, find and / or, replace option in a specified area in text., , Page Background group creates a watermark, page, Background color and page borders. Paragraph block, has specified options already discussed in Home ->, Paragraph group., Copa1182906, , Fig 6, , Fig 10 - Arrange Group, , Fig 10, Copa 11829010, , Links group creates hyperlink on texts, bookmarks and, cross references in a document., The header and footer group inserts header, footer to be, appearing on every page and page numbers to display, as to placement area., , The arrange group creates position of objects, text, elements, text wrapping, arranging objects, aligning of, objects, grouping and transformations., , Fig 7 - Text and Symbols block, , Fig 7, , References tab has six blocks., , Text group allows creating text box, quick parts likely to, create brochures, designed text as WordArt, paragraph, styles, a signature line, date and time and an object insert, option., 114, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , Copa 11829011, , Fig 11, , C, , 1182907, , Fig 11 - TOC and Footnotes Group
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Fig 15 - Write and Insert fields Group, , Fig 15, Copa 11829015, , Table of contents creates the TOC of a particular, publication document automatically and upon, modifications updatable. Footnotes tab creates footnotes, of a page, block area which includes explanatory phrases, or references. Endnote makes the note at the end of the, document., Fig 12 - Citations, Bibilography and Captions Group, , Copa 11829012, , Fig 12, , Citation and Bibliography makes an external source as, citation, reference tables and credits of authors related, to the publication. Captions tab inserts a caption, table, of figures, cross references inside a text., , While writing a letter, it has many parts, which this mail, merge creates fields of Address Block, Greetings Line,, Merged field of content, labels, etc., Fig 16 - Preview Results and Finish Groups, Fig 16, , Copa 11829016, , Fig 13 - Index and Table of Authorities Group, , Copa 11829013, , Fig 13, , Index enters a value on a main topic or sub topic and, create the index accordingly. Table of authorities has, the citation mark includes the list of the cases, statutes, and other authorities cited in the document., , On successful completion of mail merge, it can be, previewed and checked for errors for each recipients, and edit accordingly. Upon validation the mail merge, gets finished., Fig 17 - Proofing and Language Groups, Fig 17, , Fig 14 - Create and Mailmerge Groups, , Mailings tab used to create mailing of a letter or order, using common mailing features. Create block makes, envelopes print using predefined formats as well as, custom formats. Labels can also be printed to which the, delivery address is mentioned., Mail merge block is used to create mail merge of a letter,, email. If a common letter is created and to be sent to, many recipients, this option allows to create an Address, block where the recipient's info should appear. Even, selective recipients can be listed as well as a new, recipient list can be created., , Copa 11829017, , Copa 11829014, , Fig 14, , Review tab here is used for the various document areas, to be reviewed. Proofing makes easier to check Spelling, and Grammar of a document. Accidental errors can be, corrected here. Research refines the search not only, inside the document, but also the referenced documents., Thesaurus identifies the completeness of the document, using the standard language compatibility of the region, like English UK or English USA etc. Word count shows, the analysis of the document as total words, total, characters, with and without spaces, no. of paragraphs,, lines, etc. Here Text blocks can also be included for, such analysis., Language Block helps to translate a page into the, installed other languages and to change the proofing, language. It requires the direct translator service from, Microsoft Online., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , 115
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Fig 18 - Comments & Tracking Group, , Fig 20 - Document views and show Groups, , Fig 18, , Comments group inserts a comment for a specific, paragraph or text block., Tracking group finds the changes made on a document, by other authors in a protected mode. For example, if a, document is created by user X and edited by user Y, is, tracked separately with Track marks., Fig 19 - Changes, Compare and Protect Groups, , Copa 11829020, , Copa 11829018, , Fig 20, , View tab shows the way of displaying the word document., Document views have a Print Layout, a common view, of Word, Full Screen Reading, minimises the tabs and, ribbons to disappear and easy to read, Web Layout, which, previews a html compatible view, Outline, views the basic, version of document in mere text mode and Draft mode, for a text editing mode., The Rulers, Gridlines and Navigation Pane can be shown, or hidden according to user preferences., Fig 21 - Zoom / Window / Macro Groups, , Fig 19, , Changes hence made on the documents can either then, accepted or rejected. More than a document can be, compared for similarity using Compare. Also the, document can be protected from editing by other authors., , 116, , Copa 11829021, , Copa 11829019, , Fig 21, , Also the view of the page can be Zoomed to full page, two, pages view, 100% of the document and custom view. To, make easy editing a document the window can be split, into two, a new window for a document to cut paste, etc., can be created and all open word documents can be, arranged for view. While formatting the documents, for, repetition of commands the Macro option can be used. It, uses the Record option to store the set of commands and, repeat it again on other part of document or on another, document on a single click., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.6.30 to 1.6.37, COPA- Word Processing Software, Creating a file, save and other options, Objectives: At the end of this lesson you shall be able to, • explain how to create a new document, save and print, • state how to edit, format text and document styles, • brief using tables inside word document with data, • explain how to create styles in a document and save for future use, • explain Few unique features of Word 2010, • brief the mail merge processing, Fig 1 - File Info view, , Fig 3 - Print options in word, , Fig 1, Fig, 22, , Fig 3, , Copa 11829024, , Copa 11829022, , Fig 24, , Word 2010 new document can be created as usual with, Ctrl + N or through File menu New option. Basically the, file created is saved as a word document extended format, as docx in word file., Fig 2 - Save options in Word, , The saved documents can be printed using the File Menu, -> Print option and the installed printer support makes it, easy to get the document printed. If Adobe Acrobat, Professional is installed, the same document can be, stored as a PDF file for sharing purposes. Apart from, printing and storage, the file created can be published in, web as a web page or template that can be used for, future publications in same format., , Copa 11829023, , Fig 23, 2, Fig, , It can be saved using save as option in any compatible, format or old versions of office, like 2003 or earlier versions., Main utility of the word software is the creation of word, processing documents. It may be any of a format like, publication, letter, brochure, etc. Word supports all type, of formatting to design a text based presentation. Also it, supports output files in major accepted formats according, to industry standards., , Basic concepts to be noted while using Word are Text, properties. It includes Font type, Font size, Text Color,, and usual decorations of text. Also creating of paragraphs, styles are to be kept in mind. Paragraph alignment has, left, right, center and justified settings. Text elements, may contain items like ordered list, unordered list, subsection lists. They are found there paragraph formatting, block of Home Tab. Indenting of text for creating Quotes, is also there inside the same tab. According to the page, size, line spacing and paragraph spacing can be adjusted,, like before and after paragraph spaces, line heights, etc., The Styles can be predefined to use as ready to put on, places where it required. Standard templates are, available but it allows to create custom styles too., Tables can be inserted for various utilities. Normal table, has adjustable width and columns so it can simply inserted, with Insert > Table option directly., , Copyright @ NIMI Not to be Republished, , 117
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Fig 4 - Table insert wizard options, , FigFig, 276, , Fig 4, , In case of custom sized table is required, it can be created, using insert table / draw table options. Insert table allows, custom values for columns, width and other properties., Draw table creates custom table using a pen drawing tool, through which new table can be drawn according to the, available text contents., Customizable Quick Access Tool Bar, Word 2010's Quick Access Toolbar displays all the, commonly used options. It is located in the top left side, corner of the application window, near the office button., By default it displays the following three options, Save,, Undo and Redo, but is customizable and you may easily, add more options to it. (Fig 5), , Navigation Pane, In the previous versions of Microsoft Office, one has to, use the Ctrl+F hotkey to find any word or phrase from, within a document. Word 2010 has added a new magic to, this option, Ctrl+F now summons a Navigation Pane that, appears on the left side of the document. You will see the, three views available by clicking on their respective tabs,, the Heading View, Thumbnail Page View, and the Search, Result View. (Fig 7), Fig 7, , Fig 28, , Fig 26, , Copa 11829026, , Copa 11829028, , Fig 5, , Copa 11829027, , Copa 11829025, , Fig 25, , Paste Preview, , Customizable Ribbon Button, Apparently the Ribbon button in Word 2010 looks like the, one in Word 2007. But there is one big addition, you may, customize the word 2010's Ribbon button. In order to, customize the Ribbon button navigate to the following option, Office Button > Word Option > Customize Ribbon. (Fig 8), , It happens with most users that after copying and pasting, something into their document, they need to undo the, some changes. Word 2010 has made it easy for users,, now you may eliminate this unnecessary step by using, the paste preview option. It allows users to paste only the, values or the formatting. (Fig 6), 118, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished
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Improved Collaborations, , 8, FigFig29, , Copa 11829029, , Microsoft Word 2010 has a new feature called coauthoring. It allows more than one authors to edit a, document at the same time. Word 2010 tells you how, many authors are editing the document and their changes, can be viewed too. (Fig 9), , Fig 9, , Copa 11829030, , Fig 30, , Screen Capture Tool, , Copa 11829032, , Fig 10, Fig 31, , Fig Fig, 32 11, , Copa 11829031, , Word 2010 includes a feature called Screen Capturing,, now there is no need to use a third party or additional tool, to capture a screenshot in order to use it in Word, just, simply use Word 2010's built in tool to capture any area of, the screen. A Screenshot may be taken by navigating to, the following option Insert > Screenshot. (Fig 10), , The Background Removal Option, Artistic Effects, In Word 2010 users can now apply a number of snazzy, artistic effects to the pictures. In order to add the artistic, effects to your document, Navigate to the following option, Insert > Illustrations > Picture. Then browse and select, the picture you want, Once the picture is added to your, document, then the Picture Tools contextual tab is, displayed and you will be able to see the new Artistic, Effects drop down button over here. (Fig 11), , Office 2010 has an awesome option by the name of, Background Removal, which simply removes the, background of any image. Yes, you don't need Photoshop, anymore to remove the background. First insert the, picture in your Word document from the Insert > Picture, option. Then locate the Background Removal tool and get, rid of the background. (Fig 12), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 119
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Ligatures, , Copa 11829033, , Fig33, 12, Fig, , You might have heard about Ligatures. They make the, fonts look fancy and they are also used to keep letters, separate allowing you to search the text as if the font, were regular. Its true that not all fonts support ligatures,, but a large variety of the fonts supports them. You may, enable them from Font Preferences > advanced, then select, the standard only option in the ligatures drop down box., (Fig 15), Fig 15, , Fig 36, , Office Backstage, The Office Backstage is a new concept, it is the enhanced, form of the plain old office button and provides a much, user-friendly menu. It helps users to manage documents,, presentations, or spreadsheets at a greater level. (Fig 13), , Interesting feature, right? Read more about it here., , Copa 11829036, , Copa 11829034, , Fig Fig, 3413, , Improved Spell Checks, Word 2010 has added some new features to its spell, checker, now it will detect the mistake and suggest, changing the sentence., , Fig, Fig 16, , New Art Effects in WordArt, , 37, , Just like other features, WordArt has been updated with, new colorful art effects. Select the text, then click Word, Art and a list of all the available options will be displayed., (Fig 14), , 120, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , Copa 11829037, , Fig 35, , Copa 11829035, , Fig 14
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Shortcut keys in Word 2010, Objective : at the end of the lesson you shall be able to, •, , Learn the shortcut keys in MS Word., CTRL+SHIFT+A, , converts the selected text to capital letters or vice versa, , CTRL+SHIFT+F, , Displays the Font dialog box., , CTRL+SHIFT+G, , Displays the Word Count dialog box., , CTRL+SHIFT+S, , Displays the Apply Styles task pane., , ALT+R, , Displays the Review tab, , ALT+CTRL+1, , Apply Heading 1, Similarly ALT + CTRL + 2 will apply heading 2, , CTRL+SHIFT+L, , Applies Bullets, , CTRL+SHIFT+F5, , Bookmark, , CTRL + B, , Bold Text, , CTRL + I, , Italic Text, , CTRL + U, , Underline Text, , CTRL+PAGE DOWN Browse Next, CTRL+E, , Navigate to the center Paragraph, , CTRL+SHIFT+ENTER, , Column Break, , CTRL+SHIFT+C, , Copy Format, , ALT+SHIFT+F7, , Dictionary, , ALT+CTRL+S, , Splits the Document, , CTRL+SHIFT+D, , Double Underline, , CTRL+END, , End of Document, , END, , End of line, , CTRL+SHIFT+P, , Font size select, , SHIFT+F5 or ALT+CTRL+Z, , Go Back to previous state, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 121
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.38, , Typing practice using open source typing tutor tools, Objectives : At the end of this lesson you shall be able to, • understand about typing software, • typing Tutor tools., You will be able to learn touch typing quickly and efficiently, with the program's intelligent practice lessons, useful, support functions and an extensive progress tracker. You, can also play a typing game and expand the program with, open lessons or make your own to meet your specific, needs., , The Typing Tutor Advantage, , Full courses for Beginner, Advanced and Expert typists, , •, , •, , Introduction course. First time using keyboard. The, course covers all characters typed on your keyboard., , •, , Beginner course. This course helps to learn the position, of keys on the keyboard. After completing this course,, you will know which finger to use to hit each key without, looking at the keyboard. The course also covers uppercase letters, special symbols, and the numeric pad., , •, , •, , Create classes to group your students, and Import, your entire student roster using our simple Student, Import tool., , •, , Statistical Graphs & Charts, Both students and teachers have access to detailed, graphs and statistics to track progress., , •, , Complete Course - Novice to Professional, Beginner, Intermediate, Advanced, and Specialty, Lessons to help typists of all levels., , •, , Fun Interactive Typing Games, Students can take a break from the exercises to, practice with several educational typing games., , Progress Tracking, The statistics reflect your typing speed, accuracy and, time-out, complete with a summary at the end of each, lesson., , •, , •, , and it suggests your next step: Go to the next lesson, or Try again comparing the results with Course goals., , •, , •, , You can evaluate your own performance or students at, any time by simply looking at charts., , •, , overall lesson rate, typing speed( WPM, CPM, KPM,, WPS, CPS, KPS ), accuracy and time-out are enabled, in the both: table and chart presentation, , •, , also, for each lesson, statistics by each character and, keystroke in the column charts, , •, , Reporting, Access and export detailed reporting data. Reports, and graphs exist for all levels of data., , Advanced course, helps to improve your typing speed, by memorizing frequently used syllables and words., Expert course helps you to perfect the skills acquired, by typing an actual text., , Easy to Get Started, , Typing Test, Students can repeat the typing test to track their, progress over time., Helpful Typing Hints & Tips, Tips and helpful technique information is constantly, provided to reinforce proper typing techniques., , •, , On-Screen Keyboard & Hand Diagram, Key position and proper finger placement is always, displayed to keep beginners from looking at their, hands., , Copyright @ NIMI Not to be Republished, , 123
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IT & ITES, Related Theory for Exercise 1.7.39 to 1.7.41, COPA - Spread Sheet Application, Introduction to MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Features & Functions of Microsoft Excel, Whether for work or home use, an Excel spreadsheet is, the best tool in Microsoft Office for organizing data and, making lists. Although Word documents can include, tables and columns, Excel makes laying out information, for easier. Excel also has a range of functions for designing, formulas that automate calculations. Although Excel looks, intimidating at first, the program's layout is similar to other, Office applications., Cells and Worksheets, The main portion of Excel's window consists of a, spreadsheet -- or worksheet of cells. Just as with a paper, spreadsheet, each cell can contain any numbers or any, text -- unlike working with an Access database, Excel, allows to simply click on any cell and fill it however best, fits the project., In some cases, such as to track spending, if want to use, an organized series of rows and columns. Other times,, such as building a list of team members, cell order and, positioning won't play a major role. One advantage to, Excel is how simple it makes reorganizing data: select a, cell and drag its border to move it to a new spot on the, sheet., Excel Workbooks, Every Excel file, called a workbook, contains one or more, worksheets. To switch between sheets in a workbook,, use the tabs in the lower left corner of the window. Since, Excel 2010, most workbooks use the file extension XLSX,, , 124, , whereas older versions used XLS files. New copies of Excel, can read these old files, but to open a new workbook in an, old edition, the old PC needs the Office compatibility pack., Formulas and Functions, In addition to containing plain text and numbers, cells, can contain formulas, which always start with an equals, sign. With a formula, Excel displays the result of an, equation in a cell, but automatically keeps that result, up-to-date as you change its components. A basic formula, can take the place of a calculator: write "=2+4" and Excel, displays "6." Formulas also work with data in other cells:, "=A1+B1" adds the values of cells A1 and B1., For procedures other than direct arithmetic, use functions, to perform various operations on data. Functions' abilities, range from simple math, such as "AVERAGE" to average, a range of cells, to modifying text, such as "LOWER" to, convert a line to lower case., The two terms are often confused, but remember that, each cell can contain only one formula, but each formula, can use multiple functions, such as "=AVERAGE(A1,, B1)+SUM(A2, B2)" to add the sum of two cells to the, average of two other cells., The following basic window appears when you start the, excel application. Let us, now understand the various important parts of this window, as shown in fig-1., Ribbon Tabs, , Copyright @ NIMI Not to be Republished
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Copa 1203901, , Fig 1, , As with the rest of Office since 2007, Microsoft has, replaced Excel's menus with ribbon tabs as shown in, fig-2. The tab as visual menus that remain open each, tab contains a set of related features with explanatory, icons. For example, the Home tab contains the most, common options, such as font and text color, while the, Insert tab offers ways to insert tables, text boxes and, charts. One tab, File, behaves differently. File still, contains basic tasks including "New," "Open" and "Save,", but displays these tasks in a full-screen area with extra, options, called the backstage view. For example, the, "New" button in the backstage view offers a searchable, selection of templates for new workbooks., , Fig 2, , Copa 1203902, , Ribbon contains commands organized in three, , components:, Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert, Page, Layout is the examples of ribbon tabs., Groups: They organize related commands; each group, name appears below the group on the Ribbon. For, example, group of commands related to fonts or group, of commands related to alignment etc., ?Home: Use this tab when creating, formatting, and, editing a spreadsheet., This tab is arranged into the Clipboard, Font, Alignment,, Number, Styles, Cells, and Editing groups., , Insert: Use this when adding particular elements (including, graphics, PivotTables, charts, hyperlinks, and headers and, footers) to a spreadsheet. This tab is arranged into the, Tables, Illustrations, Sparkline, Filter, Charts, Links, and, Text groups., Page Layout: Use this tab when preparing a spreadsheet, for printing or reordering graphics on the sheet. This tab, is arranged into the Themes, Page Setup, Scale to Fit,, Sheet Options, and Arrange groups., Formulas: Use this tab when adding formulas and, functions to a spreadsheet or checking a worksheet for, formula errors. This tab is arranged into the Function, Library, Defined Names, Formula Auditing, and, Calculation groups. Note that this tab also contains a, Solutions group when activate certain add-in programs,, Data: Use this tab when importing, querying, outlining,, and subtotaling the data placed into a worksheet's data, list. This tab is arranged into the Get External Data,, Connections, Sort & Filter, Data Tools, and Outline, groups., Review: Use this tab when proofing, protecting, and, marking up a spreadsheet for review by others. This tab, is arranged into the Proofing, Language, Comments, and, Changes groups. Note that this tab also contains an Ink, group with a sole Start Inking button if you're running, Office 2010 on a Tablet PC or on a computer equipped, with some sort of electronic input tablet., View: Use this tab when changing the display of the, Worksheet area and the data it contains. This tab is, arranged into the Workbook Views, Show, Zoom,, Window, and Macros groups., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 125
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Title Bar, , Status Bar, , This lies in the middle and at the top of the window. Title, bar shows the program and the sheet titles., , This displays the sheet information as well as the insertion, point location. From left to right, this bar can contain the, total number of pages and words in the document,, language etc., , Help, The Help Icon can be used to get excel related help, anytime you like. Thisprovides nice tutorial on various, subjects related to excel., Zoom Control, Zoom control lets to zoom in for a closer look at your, text. The zoom control consists of a slider that user can, slide left or right to zoom in or out. The + buttons can be, clicked to increase or decrease the zoom factor., View Buttons, The group of three buttons located to the left of the Zoom, control, near the, bottom of the screen, lets to switch among excel's various, sheet views., Normal Layout view: This displays the page in normal, view., , user can configure the status bar by right-clicking, anywhere on it and byselecting or deselecting options, from the provided list, File Tab, The File tab replaces the Office button from Excel 2010., user can click it to check the Backstage view, where, user come to open or save files, create new sheets, print, a sheet, and do other file-related operations., Quick Access Toolbar, TheFile tab and its purpose is to provide a convenient, resting place for the Excel's most frequently used, commands. And customize this toolbar based on the, comfort., Dialog Box Launcher(Fig-3), , Page Layout view: This displays pages exactly as they, will appear when printed. This gives a full screen look of, the document., , This appears as a very small arrow in the lower-right, corner of many groups on the Ribbon. Clicking this button, opens a dialog box or task pane that providesmore, options about the group., , Page Break view: This shows a preview of where pages, will break when printed., , If already have an opened sheet then it will display a, window showing the, , Sheet Area, , details about the opened sheet as shown fig-4. Backstage, view shows threecolumns when select most of the, available options in the first column., , The area where to enter data. The flashing vertical bar, is called the insertion point and it represents the location, where text will appear when type., Row Bar, , Fig 3, , Rows are numbered from 1 onwards and keeps on, increasing as to keepentering data. Maximum limit is, 1,048,576 rows., Columns are numbered from A onwards and keeps on, increasing as to keep, entering data. After Z, it will start the series of AA, AB, and so on. Maximum limit is 16,384 columns., First column of the backstage view will have the following options as shown in, Table-1:, Option, , Description, , Save, , If an existing sheet is opened, it would be saved as is,otherwise it will display a dialogue, box asking for thesheet name., , Save As, , A dialogue box will be displayed asking for sheet nameand sheet type. By default, it will, save in sheet 2010 format with extension .xlsx., , Open, , This option is used to open an existing excel sheet., , Close, , This option is used to close an opened sheet., , Info, , This option displays the information about the openedsheet., , 126, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , Copa 1203903, , Column Bar
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Option, , Description, , Recent, , This option lists down all the recently opened sheets., , New, , This option is used to open a new sheet., , Print, , This option is used to print an opened sheet., , Save & Send, , This option saves an opened sheet and displays options to send the sheet using email etc., , Help, , You can use this option to get the required help about excel 2010., , Options, , Use this option to set various option related to excel 2010., , Exit, , Use this option to close the sheet and exit., , Sheet Information, When click Info option available in the first column, it, displays the following information in the second column, of the backstage view:, , Fig 5, , Compatibility Mode: If the sheet is not a native excel, 2007/2010 sheet, a Convert button appears here,, enabling to easily update its format. Otherwise, this, category does not appear., Permissions: This option used to protect the excel sheet., And can set a password so that nobody can open the, sheet, or lock the sheet so that nobody can edit the sheet., , Versions: If the sheet has been saved several times,, and may be able to access previous versions of it from, this section., Sheet Properties, When click Info option available in the first column, it, displays various properties in the third column of the, backstage view. These properties include sheet size, title,, tags, categories etc., user can also edit various properties. Just try to click on, the property value and if property is editable, then it will, display a text box where can add the text like title, tags,, comments, Author., , Copa 1203905, , Prepare for Sharing: This section highlights important, information should know about the sheet before send it, to others, such as a record of the edits the made as, developed the sheet., , Sheet area is the place of type the text. The flashing vertical, bar iscalled the insertion point and it represents the location, where text will appearwhen type. When click on a box, then the box is highlighted. When double click the box,, the flashing vertical bar appears and can start entering the, data., So, just keep the mouse cursor at the text insertion point, and start typing whatever text would like to type. We, have typed only two words "HelloExcel" as shown fig-6., The text appears to the left of the insertion point., Fig 6, , Entering values, , Copa 1203906, , A new sheet is displayed by default when open an excel, sheet as shown in the fig-5 screen shot., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 127
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There are following three important points, which would help while typing:, • Press Tab to go to next column., •, , Press Enter to go to next row., , •, , Press Alt + Enter to enter a new line in the same, column., , Move Around in Excel 2010, Excel provides a number of ways to move around a sheet, using the mouse and the keyboard., , First of all, let us create some sample text before we, proceed. Open a new excel sheet and type any data. A, sample data table as shown table-2 and fig-7., , OrderDate, , Region, , Rep, , Item, , Units, , Unit Cost, , Total, , 1/6/2010, , East, , Jones, , Pencil, , 95, , 1.99, , 189.05, , 1/23/2010, , Central, , Kivell, , Binder, , 50, , 19.99, , 999.5, , 2/9/2010, , Central, , Jardine, , Pencil, , 36, , 4.99, , 179.64, , 2/26/2010, , Central, , Gill, , Pen, , 27, , 19.99, , 539.73, , 3/15/2010, , West, , Sorvino, , Pencil, , 56, , 2.99, , 167.44, , 4/1/2010, , East, , Jones, , Binder, , 60, , 4.99, , 299.4, , 4/18/2010, , Central, , Andrews, , Pencil, , 75, , 1.99, , 149.25, , 5/5/2010, , Central, , Jardine, , Pencil, , 90, , 4.99, , 449.1, , 5/22/2010, , West, , Thompson, , Pencil, , 32, , 1.99, , 63.68, , 6/8/2010, , East, , Jones, , Binder, , 60, , 8.99, , 539.4, , 6/25/2010, , Central, , Morgan, , Pencil, , 90, , 4.99, , 449.1, , 7/12/2010, , East, , Howard, , Binder, , 29, , 1.99, , 57.71, , 7/29/2010, , East, , Parent, , Binder, , 81, , 19.99, , 1,619.19, , 8/15/2010, , East, , Jones, , Pencil, , 35, , 4.99, , 174.65, , Moving with Mouse, , Table-2, , Mouse can easily move the insertion point by clicking in, the text anywhere on the screen. Sometime if the sheet, is big then user cannot see a place need to move. In, such situations, to use the scroll bars, as shown fig-8, screen shot., , Copa 1203907, , Fig 7, , 128, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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User can move box by box or sheet by sheet. Now click, in any box containing data in the sheet. It would have to, hold down the Ctrl key while pressing an arrow key, which, moves the insertion point as described here -, , Fig 8, , Copa 1203908, , Key Combination, , Where the Insertion Point, Moves, , Ctrl +, , Î, , To the last box containing data, of the current row., , Ctrl +, , Í, , To the first box containing data, of the current row., , Ctrl +, , Ï, , To the first box containing data, of the current column., , Ctrl +, , Ð, , To the last box containing data, of the current column., , Ctrl + Page Up, , To the sheet in the left of the, current sheet., , user can scroll the sheet by rolling mouse wheel, which, is equivalent to clicking the up-arrow or down-arrow, buttons in the scroll bar., , Ctrl + Page Down, , To the sheet in the right of the, current sheet., , Ctrl + Home, , To the beginning of the sheet., , Moving with Scroll Bars, , Ctrl + End, , To the end of the sheet., , As shown in the above screen capture, there are two, scroll bars: one for moving vertically within the sheet,, and one for moving horizontally. Using the vertical scroll, bar, user may ?, •, , Move upward by one line by clicking the upwardpointing scroll arrow., , •, , Move downward by one line by clicking the downwardpointing scroll arrow., , •, , Move one next page, using next page button, (footnote)., , •, , Move one previous page, using previous page button, (footnote)., , •, , Use Browse Object button to move through the sheet,, going from one chosen object to the next., , Moving with Go To Command, Press F5 key to use Go To command as shown in fig-9,, which will display a dialogue box contains various options, to reach to a particular box., Normally, we use row and column number, for example, K5 and finally press Go To button., , Fig 9, , Moving with Keyboard, , Keystroke, , Where the Insertion Point Moves, , Î, , Forward one box, , Í, , Back one box, , Ï, , Up one box, , Ð, , Down one box, , PageUp, , To the previous screen, , Copa 1203909, , The following keyboard commands, used for moving, around your sheet, also move the insertion point -, , PageDown To the next screen, Home, , To the beginning of the current screen, , End, , To the end of the current screen, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 129
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Conditional Formatting, , •, , MS Excel 2010 Conditional Formatting feature enables, to format a range of values so that the values outside, certain limits, are automatically formatted., Choose Home Tab " Style group " Conditional Formatting, dropdown., Various Conditional Formatting Options, •, , Top/Bottom Rules: It opens a continuation menu, with various options for defining the formatting rules, that highlight the top and bottom values, percentages,, and above and below average values in the cell, selection., , Suppose want to highlight the top 10% rows user can do, this with these Top/Bottom rules as shown in fig-12., , Fig 12, , Highlight Cells Rules ? It opens a continuation menu, with various options for defining the formatting rules, that highlight the cells in the cell selection that contain, certain values, text, or dates, or that have values, greater or less than a particular value, or that fall, within a certain ranges of values., , Copa 12039012, , Suppose to find cell with Amount 0 and Mark them as, red. Choose Range of cell " Home Tab " Conditional, Formatting DropDown " Highlight Cell Rules " Equal To as, on fig-10., , Fig 10, , Copa 12039010, , •, , Data Bars(fig-13): It opens a palette with different, color data bars that can apply to the cell selection to, indicate their values relative to each other by clicking, the data bar thumbnail., , With this conditional Formatting data Bars will appear in, each cell., , Fig 13, , After Clicking ok, the cells with value zero are marked as, red as shown in fig-11., , Copa 12039013, , Fig 11, , •, , Color Scales (Fig-14): It opens a palette with different, three- and two-colored scales that can apply to the, cell selection to indicate their values relative to each, other by clicking the color scale thumbnail., , Copa 12039011, , See the below screenshot with Color Scales, conditional, formatting applied., , 130, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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Linking Excel Worksheet Data Overview, , Fig 14, , In Excel, a link is a formula that dynamically pulls in, data from a cell in another worksheet. The worksheet, can be in the same workbook or a different workbook., , Copa 12039014, , The destination worksheet is the worksheet that contains, the link formula. The worksheet containing the data that, will be brought in is called the source worksheet., , • Icon Sets (Fig-15)? It opens a palette with different, sets of icons that can apply to the cell selection to indicate, their values relative to each other by clicking the icon, set., See the below screenshot with Icon Sets conditional, formatting applied., , Any time the cell value in the source worksheet changes,, the cell containing the link formula will be updated as, well the next time the spreadsheet containing the link, formula is opened. This is just one of many reasons the, Excel software program is so powerful., Need for Linking Spreadsheet Data, The ability to create links often eliminates the need to, have identical data entered and updated in multiple, sheets. This saves time, reduces errors, and improves, data integrity. For example, a company's prices can be, stored in a 'Master Price List' worksheet, and others, needing pricing data can link to that worksheet., Consider a Sales Manager who has a detailed, spreadsheet for each salesperson, but would like a, summary sheet to compare salespersons' performance, and create grand totals. The summary sheet (destination), would bring in data from all the salespersons' sheets, (source)., , Fig 15, , Create the Worksheet Link, Before creating the link, format the cell, containing the link formula in the destination, worksheet to equal the format of the source data., For example, if the data from the source spreadsheet is, currency with 2 decimal points, then first format the target, cell for currency with 2 decimal places., • New Rule: It opens the New Formatting Rule dialog, box, where define a custom conditional formatting rule, to apply to the cell selection., • Clear Rules: It opens a continuation menu, where, can remove the conditional formatting rules for the cell, selection by clicking the Selected Cells option, for the, entire worksheet by clicking the Entire Sheet option, or, for just the current data table by clicking the This Table, option., • Manage Rules: It opens the Conditional Formatting, Rules Manager dialog box, edit and delete particular rules, as well as adjust their rule precedence by moving them, up or down in the Rules list box., Link Excel Spreadsheet Data, Microsoft Excel provides the ability for cells in one, worksheet to be linked to cells in one or more other, worksheets. This is a great productivity tool and can, reduce the need for additional worksheets!, , METHOD ONE, 1. In the source worksheet, select the cell need to link, to and click the Copy button on the Home tab. Or, press Ctrl+C, or right-click and select Copy., 2. Switch to the destination spreadsheet and click the, cell want to link. Then, depending on the version of, Excel:, •, , Excel 2007, 2010, and 2013: On the Home tab, click, the down arrow below Paste and click Paste Link. In, newer versions also right-click and select the Paste, Link from the Paste menu., , •, , Excel 2003 and older versions: On the Edit menu,, click Paste Special, and then click Paste Link., , 3. Return to the source worksheet and press ESC to, remove the animated border around the cell., METHOD TWO, This is a fast method that works in a different order than, Method One., , 1. In the destination worksheet cell that will contain the, link formula, enter an equal sign (=)., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, 131, , Copyright @ NIMI Not to be Republished
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2. In the source worksheet, click in the cell that contains, the data and press the Enter key., , Fig 16, , Link Formula Example(Fig-16), In the example below, using Method One, we click in cell, B6 in the source worksheet and click Copy. Then, on the, destination worksheet, we click in cell B3, and paste the, link. The value ($3,500) automatically displays., , Copa 12039016, , Follow the same steps to link the data from the Denver, and Seattle worksheets to the Store Totals worksheet., And first formatted the cells to display the data as Currency., (Fig 16), , 132, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.7.42 - 1.7.46, COPA - Spread Sheet Application, Functions and formulas in MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Formulas in MS Excel, formula, worksheet will be just simple tabular, representation of data. A formula consists of special code,, which is entered into a cell. It performs some calculations, and returns a result, which is displayed in the cell., Formulas use a variety of operators and worksheet, functions to work with values and text. The values and, text used in formulas can be located in other cells, which, makes changing data easy and gives worksheets their, dynamic nature. For example, it can quickly change the, data in a worksheet and formulas works., Elements of Formulas, A formula can consist of any of these elements ?, •, , Creating Formula, For creating a formula need to type in the Formula Bar., Formula begins with '=' sign. When building formulas, manually, and can either type in the cell addresses or, can point to them in the worksheet. Using the Pointing, method to supply the cell addresses for formulas is often, easier and more powerful method of formula building., When using built-in functions, to click the cell or drag, through the cell range that want to use when defining, the function's arguments in the Function Arguments, dialog box as shown in Fig 1., Fig Fig, 17 1, , Mathematical operators, such as +(for addition), and *(for multiplication), , Example •, , Copa 12039017, , =A1+A2 Adds the values in cells A1 and A2., Values or text, , Example =200*0.5 Multiplies 200 times 0.5. This formula uses only, values, and it always returns the same result as 100., •, , Cell references (including named cells and, ranges), , Example =A1=C12 Compares cell A1 with cell C12. If the cells, are identical, the formula returns TRUE; otherwise, it, returns FALSE., •, , Worksheet functions (such as SUMor AVERAGE), , Example =SUM(A1:A12) Adds the values in the range A1:A12., , As soon as complete a formula entry, Excel calculates, the result, which is then displayed inside the cell within, the worksheet (the contents of the formula, however,, continue to be visible on the Formula bar anytime the, cell is active). If you make an error in the formula that, prevents Excel from being able to calculate the formula, at all, Excel displays an Alert dialog box suggesting how, to fix the problem., Functions in Formula, Many formulas are create use available worksheet, functions. These functions enable to greatly enhance the, power of the formulas and perform calculations that are, difficult if use only the operators. For example, and can, use the LOG or SIN function to calculate the Logarithm, or Sin ratio. And cannot do this complicated calculation, by using the mathematical operators alone., , Copyright @ NIMI Not to be Republished, , 133
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Using Functions, , Function Arguments, , When type = sign and then type any alphabet the, searched functions will showfig 2., , In the above examples, notice that all the functions used, parentheses. The information inside the parentheses is, the list of arguments., , Fig 2, Fig 18, , Copa 12039018, , Functions vary in how they use arguments. Depending, on what it has to do, a function may use., , Suppose need to determine the largest value in a range., A formula can't tell the answer without using a function., We will use formula that uses the MAX function to return, the largest value in the range B3:B8 as, =MAX(A1:D100)as shown in fig 3., , FigFig, 193, , •, , No arguments - Examples ? Now(), Date(), etc., , •, , One argument - UPPER(), LOWER(), etc., , •, , A fixed number of arguments - IF(), MAX(), MIN(),, AVERGAGE(), etc., , •, , Infinite number of arguments, , •, , Optional arguments, , Built In Functions, MS Excel has many built in functions, which we can use, in our formula. To see all the functions by category,, choose Formulas Tab " Insert Function as shown in fig-5., Then Insert function Dialog appears from which we can, choose the function., , Another example of functions. Suppose to find if the cell, of month is greater than 1900 then we can give Bonus to, Sales representative. The we can achieve it with writing, formula with IF functions as =IF(B9>1900,"Yes","No"), as shown in fig 4., , Copa 12039021, , Copa 12039019, , Fig 5, Fig 21, , Functions by Categories, Let us see some of the built in functions in MS Excel., Text Functions, LOWER: Converts all characters in a supplied text string, to lower case, , FigFig, 204, , UPPER : Converts all characters in a supplied text string, to upper case, TRIM : Removes duplicate spaces, and spaces at the, start and end of a text string, CONCATENATE : Joins together two or more text, strings., , Copa 12039020, , Fig 4, , 134, , LEFT : Returns a specified number of characters from, the start of a supplied text string., MID : Returns a specified number of characters from, the middle of a supplied text string, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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RIGHT : Returns a specified number of characters from, the end of a supplied text string., LEN: Returns the length of a supplied text string, FIND: Returns the position of a supplied character or text, string from within a supplied text string (case-sensitive)., Date & Time, DATE: Returns a date, from a user-supplied year, month, and day., TIME: Returns a time, from a user-supplied hour, minute, and second., DATEVALUE: Converts a text string showing a date, to, an integer that represents the date in Excel's date-time, code., , two supplied numbers., Filters in MS Excel, Filtering data in MS Excel refers to displaying only the, rows that meet certain conditions. (The other rows gets, hidden.), Using the store data, if user interested in seeing data, where Shoe Size is 36, then set filter to do this. Follow, the below mentioned steps to do this., •, , Place a cursor on the Header Row., , •, , Choose Data Tab ¾ Filter to set filter as shown in, fig 6., , Fig 22Fig 6, , TIMEVALUE: Converts a text string showing a time, to, a decimal that represents the time in Excel., NOW: Returns the current date & time., TODAY: Returns today's date., Statistical, , Copa 12039022, , MAX: Returns the largest value from a list of supplied, numbers., MIN: Returns the smallest value from a list of supplied, numbers., AVERAGE: Returns the Average of a list of supplied, numbers., COUNT: Returns the number of numerical values in a, supplied set of cells or values., COUNTIF: Returns the number of cells (of a supplied, range), that satisfies a given criteria., SUM: Returns the sum of a supplied list of numbers, , •, , Click the drop-down arrow in the Area Row Header and, remove the check mark from Select All, which unselects, everything., , •, , Then select the check mark for Size 36 which will filter, the data and displays data of Shoe Size 36 as shown, in fig-23., , •, , Some of the row numbers are missing; these rows, contain the filtered (hidden) data., , •, , There is drop-down arrow in the Area column now shows, a different graphic - an icon that indicates the column, is filtered. (Fig 7), , Logical, AND: Tests a number of user-defined conditions and, returns TRUE if ALL of the conditions evaluate to TRUE,, or FALSE otherwise, OR: Tests a number of user-defined conditions and, returns TRUE if ANY of the conditions evaluate to TRUE,, or FALSE otherwise., NOT: Returns a logical value that is the opposite of a, user supplied logical value or expression i.e. returns, FALSE if the supplied argument is TRUE and returns, TRUE if the supplied argument is FAL, , Fig 7, Fig 23, , Math & Trig, , SIGN: Returns the sign (+1, -1 or 0) of a supplied number., SQRT: Returns the positive square root of a given, number., MOD: Returns the remainder from a division between, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , Copa 12039023, , ABS: Returns the absolute value (i.e. the modulus) of a, supplied number., , 135
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Using Multiple Filters(fig-24), , 10, FigFig26, , Filtering of records by multiple conditions i.e. by multiple, column values. Suppose after size 36 is filtered,need to, have the filter where color is equal to Coffee. After setting, filter for Shoe Size, choose Color column and then set, filter for color. (Fig 8), , Copa 12039026, , Copa 12039024, , Fig 8, Fig 24, , -, , Values - alphabetically or numerically., , -, , Cell Color - Based on Color of Cell., , Sorting in MS Excel, , -, , Font Color - Based on Font color., , Sorting data in MS Excel rearranges the rows based on, the contents of a particular column. sort a table to put, names in alphabetical order Or sort data by Amount from, smallest to largest or largest to smallest., , -, , Cell Icon - Based on Cell Icon., , •, , Clicking Ok will sort the data as on fig 11., , To Sort the data follow the steps mentioned below., •, , Fig Fig, 27 11, , Select the Column to sort data as on fig 9., , Choose Data Tab " Sort Below dialog appears., , •, , If the user sort data based on a selected column,, Choose Continue with the selection or if the data, sorting based on other columns, choose Expand, Selection., , •, , Sort the data based on the below Conditions as on, fig 10., , Sorting option is also available from the Home Tab. Choose, Home Tab " Sort & Filter. You can see the same dialog to, sort records as on fig 12., , Fig 28, , Fig 12, , Copa 12039028, , •, , Copa 12039027, , 12039025, , 9, FigFig25, , 136, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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Ranges in MS Excel:, A cell is a single element in a worksheet that can hold a, value, some text, or a formula. A cell is identified by its, address, which consists of its column letter and row, number. For example, cell B1 is the cell in the second, column and the first row., , to return the navigation keys to normal movement., •, , Type the cell or range address into the Name box and, press Enter. Excel selects the cell or range that, specified. (Fig 13), , Fig 13, Fig 29, , A group of cells is called a range. You designate a range, address by specifying its upper-left cell address and its, lower-right cell address, separated by a colon., •, , C24, , - A range that consists of a single cell., , •, , A1:B1, , - Two cells that occupy one row and two, columns., , •, , A1:A100 - 100 cells in column A., , •, , A1:D4, , Copa 12039029, , Example of Ranges:, , - 16 cells (four rows by four columns)., , Selecting Ranges (Fig-29), Selecting a range in several ways ?, , Selecting Complete Rows and Columns (Fig-30), , •, , Press the left mouse button and drag, highlighting, the range. Then release the mouse button. If drag to, the end of the screen, the worksheet will scroll., , When user need to select an entire row or column.and, can select entire rows and columns in much the same, manner as select ranges:, , •, , Press the Shift key while uses the navigation keys to, select a range., , •, , Click the row or column border to select a single row, or column., , •, , Press F8 and then move the cell pointer with the, navigation keys to highlight the range. Press F8 again, , •, , To select multiple adjacent rows or columns, click a, row or column border and drag to highlight additional, rows or columns., , •, , To select multiple (nonadjacent) rows or columns,, press Ctrl while click the row or column borders., (Fig 14), , Copa 12039030, , Fig, Fig14, 30, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , 137
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IT & ITES, Related Theory for Exercise 1.7.47 & 1.7.48, COPA - Spread Sheet Application, Data validations and Table management in MsExcel 2010, Objectives : At the end of this lesson you shall be able to, • data Validation, • data Table with Example, • charts and its types, • pivot table and pivot chart, • page setup and printing worksheet, • excel shortcut keys, Data Validation, , •, , MS Excel data validation feature allows to set up certain, rules that dictate what can be entered into a cell. For, example, user want to limit data entry in a particular cell, to whole numbers between 0 and 10. If the user makes, an invalid entry, and display a custom message as shown, fig 1., , Decimal - The user must enter a number. For example,, you can specify that the entry must be greater than or, equal to 10 and less than or equal to 20., , •, , List - The user must choose from a list of entries you, provide. You will create drop-down list with this, validation. You have to give input ranges then those, values will appear in the drop-down., , •, , Date - The user must enter a date. You specify a valid, date range from choices in the Data drop-down list., For example, you can specify that the entered data, must be greater than or equal to January 1, 2013, and, less than or equal to December 31, 2013., , •, , Time - The user must enter a time. Specify a valid, time range from choices in the Data drop-down list., For example, user can specify that the entered data, must be later than 12:00 p.m., , •, , Text Length - The length of the data (number of, characters) is limited. specify a valid length by using, the Data drop-down list. For example, that the length, of the entered data be 1 (a single alphanumeric, character)., , •, , Custom - To use this option, must supply a logical, formula that determines the validity of the user's entry, (a logical formula returns either TRUE or FALSE)., , Copa 12039031, , FigFig311, , Validation Criteria, To specify the type of data allowable in a cell or range,, follow the steps below, which shows all the three tabs of, the Data Validation dialog box., •, , Select the cell or range., , •, , Choose Data " Data Tools " Data Validation. Excel, displays its Data Validation dialog box having 3 tabs, settings, Input Message and Error alert., , Input Message Tab(fig 2), Fig 2, , Fig 32, , Here user can set the type of validation. Choose an option, from the Allow drop-down list. The contents of the Data, Validation dialog box will change, displaying controls, based on your choice., •, , Any Value - Selecting this option removes any existing, data validation., , Whole Number - The user must enter a whole, number.For example, you can specify that the entry, must be a whole number greater than or equal to 50., 138, •, , Copyright @ NIMI Not to be Republished, , Copa 12039032, , Settings Tab
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User can set the input help message with this tab. Fill the, title and Input message of the Input message tab and the, input message will appear when the cell is selected., , Fig 5, Fig 34, , Error Alert Tab(fig 3), , User specify an error message with this tab. Fill the title, and error message. Select the style of the error as stop,, warning or Information as per user need., , Copa 12039034, , Copa 12039032, , FigFig, 323, , Now, for creation of data table select the range of data, table. Choose Data Tab " What-If analysis dropdown ", Data table. It will display dialogue asking for Input row and, Input Column. Give the Input row as Price cell (In this, case cell B3) and Input column as quantity cell (In this, case cell B4) as shown in fig 6., Fig 6, Fig 35, , Data Table with Example (Fig 4), Fig 4, , Copa 12039033, , Copa 12039035, , Fig 33, , Fig 36, , Fig 7, , Copa 12039036, , Here user have the Price and quantity of many values., Also, have the discount for that as third variable for, calculating the Net Price. And can keep the Net Price, value in the organized table format with the help of the, data table. The Price runs horizontally to the right while, quantity runs vertically down. We are using a formula to, calculate the Net Price as Price multiplied by Quantity, minus total discount (Quantity * Discount for each, quantity) as shown in fig 5., , Clicking OK will generate data table as shown in fig 7. It, will generate the table formula. And change the price, horizontally or quantity vertically to see the change in, the Net Price., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 139
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Charts, A chart is a visual representation of numeric values., Charts (also known as graphs) have been an integral, part of spreadsheets. Charts generated by early, spreadsheet products were quite crude, but thy have, improved significantly over the years. Excel provides, you with the tools to create a wide variety of highly, customizable charts. Displaying data in a well-conceived, chart can make your numbers more understandable., Because a chart presents a picture, charts are particularly, useful for summarizing a series of numbers and their, interrelationships., , •, , Stock: This chart type is most often used for stock, price data, but can also be used for scientific data, (for example, to indicate temperature changes)., , •, , Surface: A surface chart is useful to find the optimum, combinations between two sets of data. As in a, topographic map, colors and patterns indicate areas, that are in the same range of values., , •, , Doughnut: Like a pie chart, a doughnut chart shows, the relationship of parts to a whole; however, it can, contain more than one data series., , •, , Bubble: Data that is arranged in columns on a, worksheet, so that x values are listed in the first, column and corresponding y values and bubble size, values are listed in adjacent columns, can be plotted, in a bubble chart., , •, , Radar: A radar chart compares the aggregate values, of a number of data series., , Types of Charts, There are various chart types available in MS Excel as, shown in fig 8., Fig 8, , Fig 37, , Creating Chart, , •, , Column: Column chart shows data changes over a, period of time or illustrates comparisons among items., , •, , Bar: A bar chart illustrates comparisons among, individual items., , •, , Pie: A pie chart shows the size of items that make up, a data series, proportional to the sum of the items. It, always shows only one data series and is useful to, emphasize a significant element in the data., , •, , Line: A line chart shows trends in data at equal, intervals., , •, , Area: An area chart emphasizes the magnitude of, change over time., , •, , X Y Scatter: An xy (scatter) chart shows the, relationships among the numeric values in several, data series, or plots two groups of numbers as one, series of xy coordinates., , •, , Select the data for which you want to create the chart., , •, , Choose Insert Tab " Select the chart or click on the, Chart groupto see various chart types., , •, , Select the chart of the choice and click OK to generate, the chart as shown in fig 9., Fig 9, Fig 38, , Copa 12039038, , Copa 12039037, , To create charts for the data by below mentioned steps., , Editing Chart, You can edit the chart at any time after you have created, it., •, , 140, , select the different data for chart input with Right click, on chart " Select data. Selecting new data will, generate the chart as per the new data, as shown in, fig 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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This will generate the Pivot table pane as shown in fig-41., various options available in the Pivot table pane. And can, select fields for the generated pivot table. (Fig 13), , Fig 10, Fig 39, , •, , change the X axis of the chart by giving different inputs, to X-axis of chart., , •, , change the Y axis of chart by giving different inputs to, Y-axis of chart., , Pivot Tables, A pivot table is essentially a dynamic summary report, generated from a database. The database can reside in, a worksheet (in the form of a table) or in an external, data file. A pivot table can help transform endless rows, and columns of numbers into a meaningful presentation, of the data. Pivot tables are very powerful tool for, summarized analysis of the data., Pivot tables are available under Insert tab " PivotTable, dropdown " PivotTable., Pivot Table Example (Fig-40), Now, let us see Pivot table with the help of example., Suppose huge data of voters and need to see the, summarized data of voter Information per party, use the, Pivot table for it. Choose Insert tab " Pivot Table to insert, pivot table. MS Excel selects the data of the table. and, select the pivot table location as existing sheet or new, sheet. (Fig 11), , Copa 12039041, , Copa 12039039, , FigFig, 4112, , •, , Column labels: A field that has a column orientation, in the pivot table. Each item in the field occupies a, column., , •, , Report Filter: User can set the filter for the report as, year, and then data gets filtered as per the year., , •, , Row labels: A field that has a row orientation in the, pivot table. Each item in the field occupies a row., , •, , Values area: The cells in a pivot table that contain, the summary data. Excel offers several ways to, summarize the data (sum, average, count, and so, on)., , After giving input fields to the pivot table, it generates the, pivot table with the data as shown in fig 13., FigFig, 4213, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , Copa 12039042, , Copa 12039040, , Fig 40Fig 11, , 141
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Pivot Charts, , •, , A pivot chart is a graphical representation of a data, summary, displayed in a pivot table. A pivot chart is, always based on a pivot table. Although Excel lets to, create a pivot table and a pivot chart at the same time,, user can't create a pivot chart without a pivot table. All, Excel charting features are available in a pivot chart., , Press Ctrl+P and then click the Print button (or press, Enter)., , FigFig, 4516, , Pivot charts are available under Insert tab ¾ PivotTable, dropdown ¾ PivotChart., Pivot Chart Example, , Copa 12039045, , Suppose huge data of voters and need to see the, summarized view of the data of voter, Information per party in the form of charts, then use the, Pivot chart for it. Choose Insert tab ¾ Pivot Chart to, insert the pivot table. (Fig 14), , FigFig, 4314, Adjusting Common Page Setup Settings, , Copa 12039043, , User can adjust the print settings available in the Page, setup dialogue in different ways as discussed below. Page, setup options include Page orientation, Page Size, Page, Margins, etc., , MS Excel selects the data of the table. And select the, pivot chart location as an existing sheet or a new sheet., Pivot chart depends on automatically created pivot table, by the MS Excel. generate the pivot chart in the below, fig 15., , •, , The Print screen in Backstage View, displayed when, choose File " Print., , •, , The Page Layout tab of the Ribbon., , Choosing Your Printer(fig-46), To switch to a different printer, choose File ¾ Print and, use the drop-down control in the Printer section to select, any other installed printer. (Fig 17), Fig 17, , Fig 46, , Quick Print, If user want to print a copy of a worksheet with no layout, adjustment, use the Quick Print option. There are two, ways in which we can use this option., •, , Copa 12039046, , Copa 12039044, , Fig Fig, 4415, , Specifying What You Want to Print(Fig 18), Sometimes print only a part of the worksheet rather than, the entire active area. Choose File ¾ Print and use the, controls in the Settings section to specify what to print., •, , Active Sheets: Prints the active sheet or sheets that, you selected., , Choose File " Print (which displays the Print pane),, and then click the Print button as shown in fig 16., , 142, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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•, , Entire Workbook: Prints the entire workbook, including, chart sheets., , •, , Selection: Prints only the range that selected before, choosing File ¾ Print., , MS Excel Keyboard Short-cuts, MS Excel offers many keyboard short-cuts. Below is the list of all the major shortcut keys in Microsoft Excel., (Fig 18), , Copa 12039047, , FigFig, 4718, , •, , Ctrl + A, , -, , Selects all contents of the worksheet., , •, , Ctrl + B, , -, , Bold highlighted selection., , •, , Ctrl + I, , -, , Italicizes the highlighted selection., , •, , Ctrl + K, , -, , Inserts link., , •, , Ctrl + U, , -, , Underlines the highlighted selection., , •, , Ctrl + 1, , -, , Changes the format of selected cells., , •, , Ctrl + 5, , -, , Strikethrough the highlighted selection., , •, , Ctrl + P, , -, , Brings up the print dialog box to begin printing., , •, , Ctrl + Z, , -, , Undo last action., , •, , Ctrl + F3, , -, , Opens Excel Name Manager., , •, , Ctrl + F9, , -, , Minimizes the current window., , •, , Ctrl + F10, , -, , Maximize currently selected window., , •, , Ctrl + F6, , -, , Switches between open workbooks or windows., , •, , Ctrl + Page up, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Page down, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Tab, , -, , Moves between Two or more open Excel files., , -, , Creates a formula to sum all of the above cells, , =, • Alt +, •, , Ctrl + ', , -, , Inserts the value of the above cell into cell currently selected., , •, , Ctrl + Shift + !, , -, , Formats the number in comma format., , •, , Ctrl + Shift + $, , -, , Formats the number in currency format., , •, , Ctrl + Shift + #, , -, , Formats the number in date format., , •, , Ctrl + Shift + %, , -, , Formats the number in percentage format., , •, , Ctrl + Shift + ^, , -, , Formats the number in scientific format., , •, , Ctrl + Shift + @, , -, , Formats the number in time format., , •, , Ctrl + Arrow key, , -, , Moves to the next section of text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 143
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•, , Ctrl + Space, , -, , Selects the entire column., , •, , Shift + Space, , -, , Selects the entire row., , •, , Ctrl + -, , -, , Deletes the selected column or row., , •, , Ctrl + Shift + =, , -, , Inserts a new column or row., , •, , Ctrl + Home, , -, , Moves to cell A1., , •, , Ctrl + ~, , -, , Switches between showing Excel formulas or their values in cells., , •, , F2, , -, , Edits the selected cell., , •, , F3, , -, , After a name has been created F3 will paste names., , •, , F4, , -, , Repeat last action. For example, if you changed the color of text in another, cell pressing F4 will change the text in cell to the same color., , •, , F5, , -, , Goes to a specific cell. For example, C6., , •, , F7, , -, , Spell checks the selected text or document., , •, , F11, , -, , Creates chart from the selected data., , •, , Ctrl + Shift + ;, , -, , Enters the current time., , •, , Ctrl + ;, , -, , Enters the current date., , •, , Alt + Shift + F1, , -, , Inserts New Worksheet., , •, , Alt + Enter, , -, , While typing text in a cell pressing Alt + Enter will move to the next line, allowing for multiple lines of text in one cell., , •, , Shift + F3, , -, , Opens the Excel formula window., , •, , Shift + F5, , -, , Brings up the search box., , 144, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.8.49 - 1.8.57, COPA - Image Editing and Presentations, Image editing, presentations, Objectives : At the end of this lesson you shall be able to, • Introduction to Power Point and its advantages, • Creation of slide shows, • Fine tuning of presentations, Introduction, , Working with PowerPoint 2010, , PowerPoint is a presentation graphics software program, that is part of the Microsoft Office package. It uses a, graphical approach for the presentations in the form of, slide shows that accompany the oral delivery of the topic., This program is widely used in business and classrooms, and is an effective tool when used for training purposes., , Step 1: Click the Start button., , PowerPoint 2010 allowsto create presentations for printing or online viewing using a variety of tools. These include wizards to help with the content and look and feel, of the presentations to animation tools to create moving, images., , Copa 1214901, , PowerPoint is one of the simplest computer programs, to learn. It is the easiest program used worldwide for, presentations that creates professional looking presentations. It is easy to customize presentations with company logo and has design templates that come with the, programs. In addition to an on screen slide show,, PowerPoint has printing options that allow the presenter, to provide handouts and outlines for the audience as, well as notes pages for the speaker to refer to during the, presentation., , Fig 1, , Step 2: Click All Programs option from the menu., , Fig 2, , Presentation, , Copa 1214902, , A presentation is a collection of data and information, that is to be delivered to a specific audience. A, PowerPoint presentation is a collection of electronic, slides that can have text, pictures, graphics, tables, sound, and video. This collection can run automatically or can, be controlled by a presenter., Advantage and application of PowerPoint 2010, Professional looking presentations, , •, , Animated presentations shown on a monitor or overhead screen, , •, , Notes for the speaker, , •, , Handouts for the audience, , •, , Paper printouts of your slide, , •, , Overhead projector transparencies, , •, , Movies, , Step 3: Search for Microsoft Office from the sub menu, and click it., Fig 3, , Copa 1214903, , •, , Copyright @ NIMI Not to be Republished, , 145
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Step 4: Search for Microsoft PowerPoint 2010 from the, submenu and click it., , Fig 4, , File Tab, This tab opens the Backstage view which basically allows to manage the file and settings in PowerPoint. This, can save presentations, open existing ones and create, new presentations based on blank or predefined templates. The other file related operations can also be executed from this view., Ribbon, , This will launch the Microsoft PowerPoint 2010 application and the following is the presentation window., , Copa 1214905, , Fig 5, , Copa 1214907, , Copa 1214904, , Fig 7, , The ribbon contains three components:, •, , Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert,, Page Layout are examples of ribbon tabs., , •, , Groups: They organize related commands; each, group name appears below the group on the Ribbon., For example, a group of commands related to fonts, or a group of commands related to alignment, etc., , •, , Commands: Commands appear within each group, as mentioned above., , Title Bar, This is the top section of the window. It shows the name, of the file followed by the name of the program which in, this case is Microsoft PowerPoint., Slide Area, This is the area where the actual slide is created and, edited.Add, edit and delete text, images, shapes and, multimedia is supported in this section., , PowerPoint Screen, Fig 6, , Help, The Help Icon can be used to get PowerPoint related, help anytime. Clicking on the "?" opens the PowerPoint, Help window where there is a list of common topics to, browse from. Specific topics from the search bar at the, top can also be used for searching., Zoom Options, The zoom control zooms in for a closer look at the text., The zoom control consists of a slider that can slide left, or right to zoom in or out, - and + buttons to can be used, to increase or decrease the zoom factor. The maximum, zoom supported by PowerPoint is 400% and the 100%, is indicated by the mark in the middle., , Copa 1214906, , Slide Views, The group of four buttons located to the left of the Zoom, control, near the bottom of the screen, lets to switch, between PowerPoint views., •, , 146, , Normal Layout view: 1 This displays page in normal, view with the slide on the right and a list of thumbnails to the left. This view allowsuser to edit individual, slides and also rearrange them., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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•, , Slide Sorter view: This displays all the slides as a, matrix. This view only allows the user to rearrange, the slides but not edit the contents of each slide., , •, , Reading View: This view is like a slideshow with access to the Windows task bar in case the user need, to switch windows. However, like the slideshow user, cannot edit anything in this view., , •, , First Pane ? This is the commands pane which consists of all the commands that would typically found, in the file menu of older versions. it also has the, Options menu which edits the options on the program, like customizing the ribbon., , Various commands under the first pane are described in, the table below ?, S.No, , Notes Section, , 1, , This sections allows user to add notes for the presentation. These notes will not be displayed on the screen, during the presentation; these are just quick reference, for the presenter., , Command & Description, Save, This allows user to save a new file or an existing, file in standard format. If user is working on a pre, viously saved file this will save the new changes, in the same file format. If user is working on a, new file, this command would be similar to the, Save As command., , Quick Access Toolbar, The Quick Access Toolbar is located just under the ribbon. This toolbar offers a convenient place to group the, most commonly used commands in PowerPoint. User, can customize this toolbar to suit their needs., , 2, , Save As, Allows user to specify the file name and the file, type before saving the file., , Slide Tab, 3, , This section is available only in the Normal view. It displays all the slides in sequence. User can add, delete, and reorder slides from this section., , Open, Allows user to open new PowerPoint files., , 4, , Backstage View in Powerpoint 2010, , Close, Allows user to close an existing file., , In Office 2010, Microsoft replaced the traditional file, menu with the new Backstage view. This view not only, offers all the menu items under the file menu, but additional details which makes management of files a lot, easier., , 5, , Info, Displays the information about the current file., , 6, , Recent, Lists series of recently viewed or edited, PowerPoint files., , Accessing Backstage View, User can access the Backstage view simply by clicking, on the File tab. They can exit this view by clicking on, any tab (including the File tab again). 'Esc' button on, the keyboardcanalso be pressed for the same., , 7, , New, Allows user to create a new file using blank or, pre-defined templates., , Organization of Backstage View, , 8, , The backstage view has three sections or panes., , Print, Allows user to select the printer settings and print, the presentation., , Fig 8, , 9, , Save & Send, Allows user to share your presentation with larger, audience via emails, web, cloud services, etc., , 10, , Help, Provides access to PowerPoint Help., , 11, , Options, Allows user to set various options related to, PowerPoint program., , Copa 12149008, , 12, , Exit, Closes the presentation and exits the program., , •, , Second Pane ? This is the subcommands pane. This, will list all the commands related to the main command chosen in the first pane. For example, if user, selects Print in the first pane, user get to choose the, printer and adjust the print settings in the second pane., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 147
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•, , Third Pane ? This is the preview or file information page., Depending on the command and the subcommand user, select, this pane will either display the properties of, the file or give a preview of the file., , Creating Presentation using Powerpoint 2010, PowerPoint offers a host of tools that will aid the user in creating a presentation. These tools are organized logically, into various ribbons in PowerPoint. The table below describes the various commands that can be accessed from the, different menus., Menu Category, , Ribbon Commands, , Home, , Clipboard functions, manipulating slides, fonts, paragraph settings, drawing objects and, editing functions., , Insert, , Insert tables, pictures, images, shapes, charts, special texts, multimedia and symbols., , Design, , Slide setup, slide orientation, presentation themes and background., , Transitions, , Commands related to slide transitions., , Animations, , Commands related to animation within the individual slides., , Slide Show, , Commands related to slideshow set up and previews., , Review, , Proofing content, language selection, comments and comparing presentations., , View, , Commands related to presentation views, Master slides, color settings and window arrange, ments., , Besides these depending on the objects selected in the, slide, there are other menu tabs that get enabled., Add New Slides in Powerpoint 2010, The following are the steps that allows the user to insert, a new slide ., , Step 2: The new slide is inserted. The layout of this slide, can be changed to suit the design requirements., , Fig 10, , Step 1: Right-click in the Navigation Pane under any, existing slide and click on the New Slide option., , Copa 1214909, , Copa 12149010, , Fig 9, , 148, , Step 3: To change the slide layout, right-click on the, newly inserted slide and go to the Layout option where, user can choose from the existing layout styles available ., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Subtitle Box, , Fig 11, , This is found only in slides with the Title layout. This is, indicated by "Click to add subtitle", , Copa 12149011, , Copa 12149013, , Fig 13, , Same steps can be followed to insert a new slide in between existing slides or at the end on the slide list., When we insert a new slide, it inherits the layout of its, previous slide with one exception. If inserting a new, slide after the first slide (Title slide), the subsequent slide, will have the Title and Content layout., , Fig 12, , Content Box, This is found in most of the slides that have a placeholder for adding content. This is indicated by "Click to, add text". This box allows user to add text as well as, non-text content. To add text to such a box, click anywhere on the box, except on one of the content icons in, the center and start typing., , Copa 12149014, , Copa 12149012, , Fig 14, , Adding Text in Boxes in Powerpoint 2010, PowerPoint allows users to add text to the slide in a, well-defined manner to ensure the content is well distributed and easy to read. The procedure to add the text, in a PowerPoint slide is always the same - just click in, the text box and start typing. The text will follow the default formatting set for the text box, although this formatting can be changed later as required., The most common content blocks in PowerPoint are:, , Text Only Box, This is not a default content box available in PowerPoint,, but user can create it using Slide Master, if required., This is also indicated by "Click to add text". The only, difference between the Text Only Box and the Content, Box is that the former only supports text in the content, area., , Title Box, This is typically found on slides with the title layout and, in all the slides that have a title box in them. This box is, indicated by "Click to add title"., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 149
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Fig 18, , Copa 12149016, , Fig 16, , Adding New Text Boxes in Powerpoint 2010, , Copa 12149018, , Most of the standard layouts come with the text box option. As mentioned, text boxes will have "Click to add, text" as the default text. Here are the steps to add new, text boxes in slide., Step 1: Click on the Text Box icon in the Home ribbon, under the Drawingsection., , Copa 12149016, , Fig 16, , Step 4: Alternately, user can click and drag the cursor, without releasing the click to create a text box., , Fig 19, , Step 2 : User will get the insert text box cursor that looks, like an inverted cross., , Copa 12149019, , Fig 17, , The size of the text box can be adjusted by selecting, one of the edges marked by squares or corners marked, by circles., , Copa 12149017, , Slide Show in Powerpoint 2010, , Fig 20, Copa 12149020, , Step 3: Click to insert a text box. User can now start, typing directly into the text box., , Most PowerPoint presentations are created to be run as, a slideshow. Most of these features of Powerpoint 2010, are really to help user create a good slideshow without, having to go through the entire presentation over and, over again after every minor change. Features related, to running the slideshow are grouped under the Slideshow, ribbon., , 150, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Section, , Menu Item, , Description, , Start Slideshow, , From Beginning, , Starts slideshow from beginning, , From Current Slide, , Starts slideshow from the current slide, , Broadcast Slideshow, , Allows users to broadcast the slideshows, using Microsoft's PowerPoint Broadcast Service, , Custom Slideshow, , Builds a custom slideshow by picking the slides you, want to run, , Set Up Slideshow, , Helps set up the slideshow including browser/ full screen, display, show options with or without narration/ animation,, pen and laser color during the slideshow and the slides to, be presented during the show, , Hide Slide, , Helps mark/ unmark the slide as hidden, so it is skipped or, shown during the slideshow respectively, , Rehearse Timing, , Allows users to rehearse the timing on each slide and the, entire slideshow, , Record Slideshow, , Records the slideshow including narration and animation, , Slideshow Checkboxes, , Helps set or avoid the use of narrative audio and rehearsed, timings during the show. Display media controls in the, slideshow view, , Resolution, , Defines resolution in slideshow view, , Show Presentation on, , Picks the monitor to display the presentation one - in case, of multiple monitors, , Use Presenter View, , Run presentation in Presenter view rather than just slideshow, view, , Set Up, , Monitors, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 151
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IT & ITES, Related Theory for Exercise 1.9.58 - 1.9.61, COPA - Database Management Systems, Concepts of data and Databases, Objectives : At the end of this lesson you shall be able to, • explain database structure and control, • describe Ms access database utilities., Microsoft Access is a Database Management System, (DBMS) from Microsoft that combines the relational, Microsoft Jet Database Engine with a graphical user, interface and software-development tools. It is a member, of the Microsoft Office suite of applications, included in, the professional and higher editions., •, , Microsoft Access is just one part of Microsoft's overall, data management product strategy., , •, , It stores data in its own format based on the Access, Jet Database Engine., , •, , Like relational databases, Microsoft Access also, allows you to link related information easily. For, example, customer and order data. However, Access, 2013 also complements other database products, because it has several powerful connectivity features., , •, , It can also import or link directly to data stored in, other applications and databases., , •, , As its name implies, Access can work directly with, data from other sources, including many popular PC, database programs, with many SQL (Structured, Query Language) databases on the desktop, on, servers, on minicomputers, or on mainframes, and, with data stored on Internet or intranet web servers., , •, , Access can also understand and use a wide variety, of other data formats, including many other database, file structures., , •, , You can export data to and import data from word, processing files, spreadsheets, or database files, directly., , •, , Access can work with most popular databases that, support the Open Database Connectivity (ODBC), standard, including SQL Server, Oracle, and DB2., , •, , Software developers can use Microsoft Access to, develop application software., , •, , Report (optional): Information from the database is, organized in a nicepresentation that can be printed, in an Access Report., , Architecture, •, , Access calls anything that can have a name an object., Within an Access desktop database, the main objects, are tables, queries, forms, reports, macros, data, macros, and modules., , •, , If you have worked with other database systems on, desktop computers, you might have seen the term, database used to refer to only those files in which, you store data., , •, , But, in Access, a desktop database (.accdb) also, includes all the major objects related to the stored, data, including objects you define to automate the, use of your data., , RDBMS, In the computing system (web and business applications),, there are enormous data that comes out every day from, the web. A large section of these data is handled by, Relational database management systems (RDBMS)., The idea of relational model came with E.F.Codd's 1970, paper "A relational model of data for large shared data, banks" which made data modeling and application, programming much easier. Beyond the intended benefits,, the relational model is well-suited to client-server, programming and today it is predominant technology for, storing structured data in web and business applications., MS Access - RDBMS, Microsoft Access has the look and feel of other Microsoft, Office products as far as its layout and navigational, aspects are concerned, but MS Access is a database, and, more specifically, a relational database., •, , Microsoft Access stores information which is called a, database. To use MS Access, you will need to follow, these four steps:, , Before MS Access 2007, the file extension was *.mdb,, but in MS Access 2007 the extension has been, changed to *.accdb extension., , •, , Database Creation: Create your Microsoft Access, database and specify what kindof data you will be, storing., , Early versions of Access cannot read accdb, extensions but MS Access 2007 and later versions, can read and change earlier versions of Access., , •, , An Access desktop database (.accdb or .mdb) is a, fully functional RDBMS., , •, , It provides all the data definition, data manipulation,, and data control features that you need to manage, large volumes of data., , •, , •, , Data Input: After your database is created, the data, of every business day canbe entered into the Access, database., , •, , Query: This is a fancy term to basically describe the, process of retrievinginformation from the database., , 152, , Copyright @ NIMI Not to be Republished
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You can use an Access desktop database (.accdb or, .mdb) either as a standalone RDBMS on a single, workstation or in a shared client/server mode across a, network., , •, , A desktop database can also act as the data source, for data displayed on webpages on your company, intranet., , •, , When you build an application with an Access desktop, database, Access is the, , RDBMS., Data Definition, Let us now understand what Data Definition is:, •, , •, , •, , In document or a spreadsheet, you generally have, complete freedom to define the contents of the, document or each cell in the spreadsheet., In a document, you can include paragraphs of text, a, table, a chart, or multiple columns of data displayed, with multiple fonts., In spreadsheet, you can have text data at the top to, define a column header for printing or display, and, you might have various numeric formats within the, same column, depending on the function of the row., , •, , An RDBMS allows you to define the kind of data you, have and how the data should be stored., , •, , You can also usually define rules that the RDBMS, can use to ensure the integrity of your data., , •, , For example, a validation rule might ensure that the, user can't accidentally store alphabetic characters in, a field that should contain a number., , Data Manipulation, Working with data in RDBMS is very different from, working with data in a word processing or spreadsheet, program., •, , In a word processing document, you can include, tabular data and perform a limited set of functions on, the data in the document., , •, , You can also search for text strings in the original, document and, with ActiveX controls, include tables,, charts, or pictures from other applications., , •, , In a spreadsheet, some cells contain functions that, determine the result you want, and in other cells, you, enter the data that provides the source information, for the functions., , •, , An RDBMS provides you many ways to work with, your data. For example,, , •, , You can search a single table for information or, request a complex search across several related, tables., , •, , You can update a single field or many records with a, single command., , •, , You can write programs that use RDBMS commands, to fetch data that you want to display and allow the, user to update the data., , Access uses the powerful SQL database language to, process data in your tables. Using SQL, you can define, the set of information that you need to solve a particular, problem, including data from perhaps many tables., Data Control, Spreadsheets and word processing documents are great, for solving single-user problems, but they are difficult to, use when more than one person needs to share the data., •, , When you need to share your information with others,, RDBMS gives you the flexibility to allow multiple users, to read or update your data., , •, , An RDBMS that is designed to allow data sharing, also provides features to ensure that no two people, can change the same data at the same time., , •, , The best systems also allow you to group changes, (which is also known as transaction) so that either all, the changes or none of the changes appear in your, data., , •, , You might also want to be sure that no one else can, view any part of the order until you have entered all, of it., , •, , Because you can share your Access data with other, users, you might need to set some restrictions on, what various users are allowed to see or update., , Designing a Database, The first step in creating a database is to think about, why you need it-what is its purpose? Once you know the, answer, you can begin designing your own database., Ask yourself questions like What kinds of information, will it store? How will I have to break down this information, so it can be stored in my database? How will I use the, data once it's in there?, The bookstore scenario, The best way to learn about designing a database is to, jump right in to the process. Let's pretend we work for, the bookstore, and we need to build a database for the, store to use. Let's think about what we might need the, database to do for us., The following diagram shows that we have customers and, sell books via orders, both in the store and online., , Fig 1, , Copa 1225801, , •, , The store needs a way to keep track of these things., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 153
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Determine the purpose of the database, The first step of designing a database is to determine the, purpose of the database. What do we need it to do?, At Ready-2-Read, our customers will place orders for, books. At the very least, we will want our database to, track the books we sell, the customers we sell them to,, and the date of each of the orders., The database will also be able to tell us where our, customers live when we need to send them books or, coupons. Additionally, we can use it to track our sales or, to make a bestseller list to post in the store., Plan database tables, Once we've established its purpose, we can begin about, how to break up the information into the tables the, database will need to store data. Recall that a table is a, collection of records, and each record is broken up into, the smallest pieces of needed information, called fields., , Book the customer is ordering, and the Date the order is, placed., Creating a new database with Access, When you launch Access 2007/2010, you will see the, Getting Started window., In the left pane, the template categories-including the, featured local templates-are listed, as well as the, categories on Office Online. Templates are prebuilt, databases focused on a specific task that you can, download and use immediately., You will also see the New Blank Database option, which, allows you to build your own database from scratch., , Fig 2, , Customers, , -, , Orders, , -, , Books, , Plan table fields, Once you know what tables you need, the next step is, deciding what fields belong in each table. Remember, that fields are the smallest chunk of information in any, record., Let's look at our Ready-2-Read bookstore example again., There will be several fields in our Customers table. We'll, obviously want each customer's first name and last name., We'll also need an address if we need to send a customer, his order. Email will be necessary if we need to contact, the customer if there is an issue with the order., Customers, , Books, , Orders, , First Name, , Title, , Customer, , Last Name, , Author First, , Book, , Street, , Author Last, , Date, , City, , Price, , State, , Category, , When you choose the New Blank Database option at the, top of the window, you will be prompted to rename the, database from the default name, which is, Database1.accdb. Rename the database whatever you, want. In the example below, we named the database, Ready2Read because it's the name of the store in our, scenario., Fig 3, , Copa 1225803, , -, , Copa 1225802, , Because we're planning a database to track our, customers, the books we have, and the orders our, customers place, we will need a table for each one of, these., , Pin/Zip Code, Email, We will also need several fields in the Books table. Title, and Author make sense for books. We'll need a Price for, each book. Category will help usknow what type of books, sell the best so we can order more books that fit into this, category., The Orders table will have fewer fields. We'll need this, table to track the Customer who is placing the order, the, 154, , Click Create to finish naming the database., Setting up tables, The new database opens with one table showing as a, default. It also defaults to naming this table Table1 in both, the navigation pane and the Table tab itself. You will want, to name your tables based on your database design plan., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Copa 1225804, , Naming a table, To give the table a unique name, you must first click on, the Microsoft Office button in the upper-left corner of the, application., , Copa 1225807, , Fig 7, , Fig 4, , TIP: Give your tables logical, easy-to-understand names., To rename a table:, With the table closed, right-click the Table you want to, rename in the navigation pane. Select the Rename option, that appears in the menu., Fig 8, , Next, select Save from the menu. The Save As dialog box, will appear to let you save the table whatever name you, want., Fig 6, , Copa 1225808, , Copa 1225805, , Fig 5, , The table name will be highlighted and a cursor will appear,, which means you can now type the new name right there., Left-click anywhere outside of the table name to make the, change., To close a table:, , Copa 1225806, , There are several ways to close an active table. You can, right-click the Table tab and choose Close from the menu., Fig 9, , Copa 1225809, , The new table names appear in both the navigation pane, and the Table tab itself, as you can see in the picture, below., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 155
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A more common method is to click the X that appears in, the top-right corner of the active database object window., , Copa 12258010, , Fig 10, , To open a table:, To open a table, right-click the Table name of the table, you want to open in the navigation pane, then choose, Open from the menu., , Fig 11, , Next, select Table from the Tables command group. A, new table will open in the active database object window., You must name your table using the Save command, from Microsoft Office menu., Adding fields to a table, Access 2007 allows you to add fields to tables when you, are:, •, , Working in Datasheet view, which looks like a, spreadsheet, , •, , Working in Design view, where you are able to set more, controls for your fields, , Either way, you need to know how to switch between the, two views., To switch views:, Select the Views command group from either the Home, tab (seen below) or the Datasheet tab on the Ribbon. Select, the view option you want from the menu., , A more common method is to double-click the table name, in the navigation pane. The selected table will open in, the active database object window., Adding more tables to the database, By default, Access 2007 starts out with one table. To add, more tables to the database, click the Create tab on the, Ribbon., , Fig 12, , Copa 12258013, , Copa 12258011, , Fig 13, , Adding fields in Datasheet view, By default, Access 2007 creates one field in each new, table: the ID field. This field auto-numbers to give each, record in the table a unique number identifier. Recall, that records are the rows in a table. You may want to, rename the ID field with a unique name because the ID, field appears automatically in every table you create., While this is not necessary, it may help avoid confusion, when setting up table relationships., , 156, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258014, , Copa 12258012, , Fig 14
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To add more fields to a table in Datasheet view, doubleclick the Add New Field header., Fig 15, , To add a new field to a table in Design view, click in the, cell where you want the new field and type the field name., When you switch back to Datasheet view, your new field, appears as its own column, as seen below., , The Add New Field text will disappear from the header., Name the field by typing the name directly into the header., Press the Tab key on your keyboard to move to the next, field., Adding fields in Design view, In Design view, the field names are along the lefthand, column instead of across the top like in Datasheet view,, as seen below., , Copa 12258017, , Copa 12258015, , Fig 17, , Datatypes, Every field in a table has properties and these properties, define the field's characteristics and behavior. The most, important property for a field is its data type. A field's data, type determines what kind of data it can store. MS Access, supports different types of data, each with a specific, purpose., •, , The data type determines the kind of the values that, users can store in any given field., , •, , Each field can store data consisting of only a single, data type., , Copa 12258016, , Fig 16, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 157
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Here are some of the most common data types you will find used in a typical Microsoft Access database., Type of Data, , Description, , Size, , Text or combinations of text and numbers,, Short Text, , Up to 255, , including numbers that do not require, characters. calculating (e.g. phone numbers)., , Long Text, , Lengthy text or combinations of text and, , Up to 63, 999, , numbers. characters., Numeric data used in mathematical, Number, , 1, 2, 4, or 8 bytes, , (16 bytes if set to calculations., Replication ID)., , Date/Time, , Date and time values for the years 100 through, , 8 bytes., , 9999., Currency values and numeric data used in, Currency, , mathematical calculations involving data with, , 8 bytes., , one to four decimal places., A unique sequential (incremented by 1), , 4 bytes (16 bytes if, , number or random number assigned by, AutoNumber, , set to Replication Microsoft Access whenever, a new record is ID). added to a table., Yes and No values and fields that contain only, , Yes/No, , 158, , one of two values (Yes/No, True/False, or, , 1 bit., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Here are some of the other more specialized data types, you can choose from in Access., Data Types, , Description, , Attachment, , Size, , Files, such as digital photos. Multiple files can be, attached per record. This data type is not available, , Up to about 2 GB., , in earlier versions of Access., OLE objects, , OLE objects can store pictures, audio, video, or, , Up to about 2 GB., , other BLOBs (Binary Large Objects), Hyperlink, , Text or combinations of text and numbers stored a, , Up to 8,192 (each, part of a Hyperlink, data type can, contain up to, 2048 characters)., , Lookup, , The Lookup Wizard entry in the Data Type column, in the Design view is not actually a data type. When, you choose this entry, a wizard starts to help you, , Dependent on, , define either a simple or complex lookup field., , the data type of, he lookup field., , Wizard, , A simple lookup field uses the contents of another, table or a value list to validate the contents of a, single value per row. A complex lookup field allows, you to store multiple values of the same data type, in each row., , Calculated, , You can create an expression that uses data from, , You can create, , one or more fields. You can designate different, , an expression, , result data types from the expression., , that uses data, from one or, more fields. You, can designate, different result, data types from, the expression., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 159
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MS Access - Adding Data, , Fig 21, , Adding records to tables, , Copa 12258021, , When you enter records into your table, you are, populating the database. In Access 2007, you can do this, a few different ways., To add records in the new record row:, Click the record row with the asterisk that appears at, the bottom of the table., •, Copa 12258018, , Fig 18, , Type the data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , To add records with the New Record navigation, button:, •, , Click the New Record button in the navigation bar. The, navigation bar is located in the bottom-left corner of, the open object pane., , Fig 22, , •, , Type the new information into the field., , •, , Click outside of the record row to apply the change., , To edit a record using Find and Replace:, •, , Click the Find command in the Find group on the, Ribbon., , Fig 23, Copa 12258023, , •, , Click the cell containing the information that must be, edited. A pencil icon appears to indicate edit mode., Copa 12258022, , •, , Copa 12258019, , Fig 19, , •, , Type data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , •, , The Find and Replace dialog box opens., , Fig 24, , •, , Copa 12258024, , To add records with the New Record command:, Click the New Record command in the Records group, in the Ribbon., Copa 12258020, , Fig 20, , •, , Tell Access what to find by typing it into the Find What:, area., , •, , Type the replace term in the Replace With: area., , •, , Tell Access where to look with the Look In: drop-down, list. The first choice in the drop-down list is the field, you were last in within the table., , Editing records in tables, , •, , Sometimes it is necessary to edit records in the database., Like with every other task in Access 2007, this can be, done several different ways., , Tell Access what to Match: Any part of the field, the, whole field, or just the start of the field., , •, , Tell Access how to Search: Up finds records above, the cursor, Down finds records below the cursor, and, All searches all records., , •, , Click one of the action options:, , -, , Find Next will find the next instance of the word, in the table., , •, , Type the data into the appropriate fields., , •, , Hit the Enter or the Tab key to move to the next field., , To edit a record directly:, •, , Scroll through the records, or use the navigation, buttons on the navigation bar to find the record to, edit., , 160, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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-, , Replace will put the new word into the table, overwriting, what is currently there., , -, , Cancel stops the editing process., , CAUTION: DO NOT use Replace All because it will, overwrite every instance of the Find term in the table,, which can have a serious impact on your data., To copy and paste a Record:, •, , Select the record you want to copy. Right-click, then, select Copy., , •, , Select the new record row. Right-click and select Paste., The record information appears with a new record ID, number., , To delete a record:, •, , Select the record you want to delete, then right-click, and select Delete Record., , •, , A dialog box appears, telling you the action cannot, be undone and asking if you are sure you want to, delete the record., , Let's say one of your database users has entered an order, date of January 4, 2008, in the month/date/year format as, 01/04/2008. Another user has entered an order placed on, that same date in the day/month/year format as 04/01/, 2008. If the database is tracking all sales for the month of, January 2008, it may not show both orders as placed in, January, even though both were placed on the same date., Access 2007 allows you to set field properties and data, validation rules to force the person entering data to, follow a specific format., Data types and validation rules, Data validation begins when data types are set during, the process of building tables and fields. For example, if, a field data type had been set to Currency and a text, value is entered in that table field during data entry,, Access will not accept an invalid format and will display a, validation error, like the one below., , Fig 27, , There may be other records that rely on the record you, are trying to delete. DO NOT delete a record without, knowing how it will impact the rest of your database., Fig 26, , Copa 12258027, , Copa 12258025, , Fig 25, , Data validation is accomplished by setting data validation, rules and other field properties for various fields., To set data validation rules:, •, , In Design view, highlight the field that requires a, validation rule., , •, , In the Field Properties section at the bottom half of, the window, set your validation rule using, theExpression Builder. The Expression Builder offers, common syntax to set up a data validation rule., , When you delete a record, the record number is, permanently deleted from the database table. If you, delete the last record from a table and then add a new, record, your new record numbers will appear to be out of, sequence., Data validation, Data validation is an important database concept. It is, the process by which Access tests the data that is being, entered into the database to make sure it is in an, acceptable-or valid-format., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258028, , Copa 12258026, , Fig 28, , 161
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The image below shows the resulting error message, users would see when the Category validation rule has, been broken., , Fig 29, , Validation rules work most easily with numerical fields., Rules for text fields require you to enclose each, acceptable value inside its own quotation marks,, separating them with Or, as seen above., , Copa 12258031, , Copa 12258029, , Fig 31, , Using field properties to ensure data integrity, Another way to ensure data integrity is by setting field, properties such as Field Size, Format, and Required., •, , Validation text is a specialized error message you can, set to have Access tell the user entering data the specific, way you want that person to enter it., , Field Size can be set to hold a specific number of, characters, up to as many as 255 for text fields. If, you were using a text field to hold the two-letter state, postal abbreviation, the field size could be set to 2 to, ensure no one enters a full state name into this field., , •, , To set the validation text, enter the error message exactly, as you want it to appear to users in the row directly, beneath the Validation Rule row in the Field Properties, section of Design view. For the validation rule we set for, Category, you'd set the validation text like this:, , The Format field property can be set to display text, or numbers in a standardized way. For example, text, can be set to show as all uppercase, and numbers, can be set to show scientific numbers, percentages,, or decimals., , •, , Set the Required property to Yes if you want users, entering data to be required to enter something in, the field. Choose No if users are allowed to leave the, field blank., , Validation text, , Fig 30, , Copa 12258030, , These are just some ways Access helps you ensure data, being entered into your database is valid., , 162, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.9.62 to 1.9.66, COPA - Database Management Systems, Forms, quires, and reports in access, Objectives : At the end of this lesson you shall be able to, • explain database relationship and forms, • explain quires and reports in as access, In a relational database (Access), the data in one table is, related to the data in other tables. In general, tables can, be related in one of three different ways: one-to-one, oneto-many or many-to-many. The relationship is used to, cross reference information between tables., , Defining relationships, , One to One, , •, , The kind of relationship that Microsoft Access creates, depends on how the related fields are defined:, , •, , A one-to-many relationship is created if only one of, the related fields is a primary key or has a, , •, , A one-to-one relationship is created if both of the, related fields are primary keys or have unique, indexes., , •, , A many-to-many relationship is really two one-tomany relationships with a third table whose primary, key consists of two fields the foreign keys from the, two other tables., , In a one-to-one relationship each record in one table, has at most one related record in another table., In a one-to-one relationship, each record in Table A can, have only one matching record in Table B, and each, record in Table B can have only one matching record in, Table A. This type of relationship is not common, because, most information related in this way would be in one, table. You might use a one-to-one relationship to divide, a table with many fields, to isolate part of a table for, security reasons, or to store information that applies only, to a subset of the main table., , You define a relationship by adding the tables that you, want to relate to the Relationships window, and then, dragging the key field from one table and dropping it on, the key field in the other table., , One to Many, , move a table that appears in the relationship map:, , A one-to-many relationship, often referred to as a, "master-detail" or "parent-child" relationship., , •, , Place your mouse over the table you want to move., , •, , Hold down the left mouse button, then drag the table, to a new location., , •, , Release the mouse button to drop the table in its new, place., , Many to Many, In a many-to-many relationship, a record in Table A can, have many matching records in Table B, and a record in, Table B can have many matching records in Table A., This type of relationship is only possible by defining a, third table (called a junction table) whose primary key, consists of two fields the foreign keys from both Tables, A and B. A many-to-many relationship is really two oneto-many relationships with a third table., , Understanding the relationship map, The relationship map lists all of the tables that were, selected to relate, as well as all of the fields that were, previously set up for that table. Notice that the first field, has a key icon next to it. This is the primary key for the, table., , Fig 32, , A many-to-many relationship means that for each record, in one table there can be many records in another table, and for each record in the second table there can be, many in the first., , Copa 12258032, , A one-to-many relationship is the most common type of, relationship. In a one-to-many relationship, a record in, Table A can have many matching records in Table B, but, a record in Table B has only one matching record in Table, A., , Many-to-many relationships can not be directly, represented in relational database programs and have, to be built by using two or more one-to-many, relationships., , Copyright @ NIMI Not to be Republished, , 163
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Primary and foreign keys, , Bound Forms, , A primary key is the first field in each table of the, database. You may recall that this field auto-numbers, by default, so every record in the table has its own unique, number to identify it. Access uses this number to quickly, pull information together when you run queries or reports,, which are covered later., , •, , Let us now understand what Bound Forms are ?, , •, , Bound forms are connected to some underlying data, source such as a table, query, or SQL statement., , •, , Bound forms are what people typically think of when, they think of the purpose of a form., , In the example above, the primary key for the Customers, table is Customer ID, the primary key for the Orders, table is Order ID, and the primary key for the Books, table is Book ID., , •, , Forms are to be filled out or used to enter or edit data, in a database., , •, , A foreign key is a field that is the primary field in its own, table but that shows up in another table. If you look closely, at the Orders table, the fields Customer ID and Book ID, appear there, as well as in their own respective tables., These fields are the primary key in their own tables, but, in the Orders table, they are considered foreign keys., , Examples of bound forms will typically be what users, use to enter, view or edit data in a database., , Unbound Forms, , Copa 12258033, , Fig 33, , Forms, A form is a database object that you can use to enter,, edit, or display data from a table or a query. You can use, forms to control access to data, such as which fields of, data are displayed. For example, certain users may not, need to see all of the fields in a table. Providing those, users with a form that contains just the necessary fields, makes it easier for them to use the database., , Let us look into Unbound Forms:, •, , These forms are not connected to an underlying, record or data source., , •, , Unbound forms could be dialog boxes, switch boards,, or navigation forms., , •, , In other words, unbound forms are typically used to, navigate or interact with the database at large, as, opposed to the data itself., , Types of Bound Forms, There are many types of bound forms you can create in, Access. Let us understand the types ?, Single Item Form, This is the most popular one and this is where the records, are displayed - one record at a time., Multiple Item Form, This displays multiple records at a time from that bound, data source., , create a form with a single click,, , Split Form, , 1. Open the table or query upon which you want to base, theform., , The form is divided into halves, either vertically or, horizontally. One half displays a single item or record,, and the other half displays a list or provides a datasheet, view of multiple records from the underlying data source., , 2. To create a form on which all fields from the underlying, table or query are placed, displaying one record at a, time, on the Create tab, clickForm., Copa 12258034, , Fig 34, , Forms in Access are like display cases in stores that, make it easier to view or get the items that you want., Since forms are objects through which you or other users, can add, edit, or display the data stored in your Access, desktop database, the design of your form is an important, aspect. There's a lot you can do design-wise with forms, in Microsoft Access. You can create two basic types of, forms -, , Bound forms, , -, , Unbound forms, , 164, , Form Controls, Every object on a form or report is a control and has its, own set of properties (displayed in the Property list) that, determine the characteristics of the data it contains., Some controls are linked to fields in the underlying table, or query and some are merely text or graphical objects, not related to any data source. Two of the most commonly, used controls in a form or report are text boxes and labels., 1) Label: displays unchanging or informational text often, times as headings or titles. Labels do not come from a, source in the database such as a field or expression., This is called an unbound control because it is not bound, to any data source., 2) Text Box: displays data as text and is abound control.A, bound control displaysinformation that is stored in a field, from the data Text boxes are used to display, enter, and, update values from fields in your database., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Form Sections, , Item Total:[Quantity]*[Price], , Forms consist of header, footer, and detail sections. In, forms, there are two types of headers/footers. Form, headers and footers are visible on every page of the, form. Page headers/footers only appear on a printed copy, of a form. There are never visible in Form View., Information about individual records appears in the detail, sections., , Use the Expression Builder to create calculated or, concatenated fields, , Copa 12258035, , Fig 35, , Sizing Sections, Adjust the size of the area for any of the sections, (headers, footers, detail), by dragging the horizontal, border for that section with your mouse. To adjust line, spacing in the detail section, drag the Detail border. There, is no other line spacing control., Working with Queries, Queries are questions you ask of your database. They, allow you to select certain fields out of a table, or pull, together data from various related tables and display it, together. Queries can be used to perform calculations,, and to edit the data in your tables. Queries can also form, the basis of forms and reports., Query Results, •, , •, , If a query contains fields from two or more related, tables, the results will only include records that have, related records in all the tables. (In other words, in, the query shown above, customers without records, in the Orders table will not appear in the query results.), To display such records, use an outer join (see page, 6) in your query., , You can simplify the process of creating concatenated, fields and other expressions with the Expression Builder., Create a blank column in your query grid and then click, the Builder button in the Query Setup group on the Query, Design Ribbon. The Expression Builder opens., Type the expression in the large box at the top. One, advantage is that you have way more room to type and, see your expression than you have at the top of a query, grid column!, A second advantage is that you can add fields to the, expression by double clicking them in the Expression, Categories column rather than by typing them. This, removes the possibility of typos., Fig 36, , WARNING! Any change you make in a query (adding,, deleting or editing data) WILL BE CHANGED IN THE, TABLES TOO!!!, , Sort query results, , Copa 12258036, , In Design View, click the Sort row in the column you, wish to sort by. A dropdown arrow appears; choose, Ascending or Descending. If you sort by more than one, column, the sorts will be done left-to-right., Create a concatenated field in a query, Concatenated fields combine information from two or, more fields into one. Ex: Combine first and last names, into one field, called "FullName". In Design View, click, in a blank column and type the following:, FullName:[FirstName]&" "&[LastName], (Type a space between the two sets of quotation marks,, and use square brackets around the field names.), Create a calculated field in a query, , Specify criteria in a query (Filtering), In Query Design View, click in the criteria row for the, field you want to filter, and type the criteria (ex: type, "OH" in the criteria row of the State field). When you run, the query, only records matching the criteria., , In Design View, click in a blank column and type a, mathematical expression, typing field names in square, brackets. Any of the normal mathematical operators (+ * / ^) can be used. If desired, give the expression a name, as in the sample below. The following expression, calculates a total cost by multiplying quantity times price:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 165
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Using Multiple Criteria, , Fig 37, , Copa 12258037, , You can type criteria in more than one field., •, , Criteria typed on the same line must all be met for a, record to be displayed ("AND" logic). Ex: "OH" in the, state field and "Smith" in the LastName field pulls up, only Ohio-dwelling Smiths., , •, , If criteria are typed on different lines, records matching, any of them will be retrieved ("OR" logic). Ex: "WA", and "OH" on different lines in the State field retrieves, records for both states., , Criteria Ranges, Criteria ranges broaden and customize a search. Type a, criteria range instead of a single value in the Criteria, row of the query grid., Criteria, <, , <=, , Example, , Description and Result, , <14, , Finds records where the field is less than a, certain value., Records will have values under 14., , <= #2/2/2006#, , Finds records where the field is less than, or equal to a, certain value., Records will have dates on or before February, 2, 2006, Note: dates are enclosed between # signs., , >, , >100, , Similar to above: Finds records where the, value is, , >=, , >=100, , greater than 100. The second expression displays, records where the value is greater than or, equal to 100., , =, , ="Diana", , Finds records where the value in the field is Diana., Note: text is enclosed in double quotes., , 166, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Expressions like these may be combined - for example,, a criteria of <49 Or>=100 would return records with, values below 49, or 100 or above, but not ones with, values between 49 and 99.99., Between __ And __, , Between 1 and 4, , Finds records where the field is between, the endpoints., , Is Null, , Is Null, , Finds records where the field is empty., , Is Not Null, , Is Not Null, , Finds records where the field is not empty., , Like, , Like U*, , Finds records where the criteria match parts, of the field., , Like "[U-X]*", , The * wildcard stands for any number of, characters, and, , Like, "*Korea*", , the ?wildcard stands for a single character., , Like "*ina", , The sample criteria will return records where, the field, , Like "Chi??", , 1) starts with U; 2) starts with U, V, W or X,, 3) contains, , Like "*4.99", , the letters 'Korea'; 4) ends in the letters, 'ina' as in ballerina;, 5) has five letters and begins with the letters, 'Chi' as in Chile or China; 6) is a number and, ends in the digits '4.99' as in 24.99., , Create a parameter query, , Fig 38, , Copa 12258038, , Parameters make queries flexible by letting users choose, their own criteria each time they run the query. In the, criteria box, type a phrase in square brackets; Access, will use this phrase to prompt the user for a value. Ex: In, a State field, type [Enter a state]. If the user types CA,, only California records will be retrieved., Specify a range in a parameter query, In the criteria box, type the following:, Between [___] And [____], Inside the brackets, type text telling the user what kind, of information to enter., Inner Joins vs. Outer Joins, Excel normally uses inner joins in its queries. These, queries return only those rows from both tables in the, join that match on the joining field (e.g., customers in, the Customers table with corresponding orders in the, Orders table.), If you need to display all customers, with or without, orders, as well as any available order information, you, need to use an outer join., In the query tray, double click the join line between two, related tables. The Join Properties dialog box will appear:, , Select button 2 or 3 depending on which field's records, you want to display completely., Action Queries, Action queries modify groups of records in one fell swoop., Types of action queries include:, •, , Update Queries (modify all records in a table that, meet specific criteria - ex: change the tax rate for all, Ohio customers from 5.75% to 6%), , •, , Delete Queries (remove records from a table - ex:, delete all customers whose last order date is more, than 2 years ago), , •, , Append Queries (add records to an existing table ex: at the end of the year, add the year's orders to the, end of an archive table), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 167
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•, , Make-table Queries (create a new table - ex: extract a, subset of records into a new table, for a subordinate, who needs Ohio customers only), , Other Specialized Queries, Instructions for creating and running these special query, types can be found in the Access help manual by clicking, the Help button in the upper right corner of the screen, (Internet connection required)., Find Duplicates query: Lets you locate duplicate records, in a table by displaying a field containing duplicate values, alongside other fields for comparison, to help you tell if, the record is really a duplicate., , 168, , Find Unmatched query: Lets you compare two tables, and identify records in one of the tables that have no, corresponding records in the other table., Crosstab query: This is a special type of Totals query, that presents summary information in a compact format, that is similar to a spreadsheet., Union query: Lets you review all of the data that is, returned by several similar select queries together, as a, combined set., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.67 - 1.10.69, , Concepts of network and internet, Objectives : At the end of this lesson you shall be able to, • define computer network and its advantages and disadvantages, • name and explain the types of network and their characteristics, • explain the types of topologies, • state about the cables used for network system, • name and state about the various connectors used in network system, • explain about the hub, modem and internet, • describe about the internet protocols connection sharing (ICS) using windows., Define computer network, , •, , A computer network is an interconnection of various, computer systems located at different places. In, computer network two or more computers are linked, together with a medium and data communication devices, for the purpose of communicating data and sharing, resources. The computer that provides resources to other, computers on a network is known as server. In the, network the individual computers, which access shared, network resources, are known as workstations or nodes., , Workgroup Computing: Workgroup software like, Microsoft BackOffice enables many users to, contribute to a document concurrently. This allows, for interactive teamwork., , •, , Error reduction and improve consistency: One, can reduce errors and improve consistency by having, all staff work from a single source of information, so, that standard versions of manuals and directories can, be made available, and data can be backed up from, a single point on a scheduled basis, ensuring, consistency., , Advantages of Computer Networks, The following are some of the advantages of computer, networks., •, , •, , •, , •, , •, , File Sharing: Networks offer a quick and easy way, to share files directly. Instead of using a disk or USB, key to carry files from one computer or office to, another, you can share files directly using a network., Security: Specific directories can be password, protected to limit access to authorized users. Also,, files and programs on a network can be designated, as "copy inhibit" so you don't have to worry about the, illegal copying of programs., Resource Sharing: All computers in the network can, share resources such as printers, fax machines,, modems, and scanners., Communication: Even outside of the internet, those, on the network can communicate with each other via, electronic mail over the network system. When, connected to the internet, network users can, communicate with people around the world via the, network., Flexible Access: Networks allow their users to access, files from computers throughout the network. This, means that a user can begin work on a project on, one computer and finish up on another. Multiple users, can also collaborate on the same project through the, network., , Network Application Areas, There is a long list of application areas, which can be, benefited by establishing Computer Networks. Few of, the potential applications of Computer Networks are:, 1 Information retrieval systems which search for books,, technical reports, papers and articles on particular, topics, 2 News access machines, which can search past news,, stories or abstracts with given search criteria., 3 Airline reservation, hotel booking, railway-reservation,, car-rental, etc., 4 A writer's aid: a dictionary, thesaurus, phrase, generator, indexed dictionary of quotations, and, encyclopaedias., 5 Stock market information systems which allow, searches for stocks that meet certain criteria,, performance comparisons, moving averages, and, various forecasting techniques., 6 Electronic Fund Transfer (EFT) between banks and via, cheque clearing house., 7 Games of the types that grow or change with various, enthusiasts adding to the complexity or diversity., 8 Electronic Mail Messages Systems (EMMS)., , Copyright @ NIMI Not to be Republished, , 169
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9 Corporate information systems such as marketing, information system, customer information system,, product information system, personnel information, system, etc., , A classification of computer networks can be done to distance as in the table., Interprocess (or), Distance, , 10 Corporate systems of different systems such as Order-Entry System, Centralized Purchasing, Distributed Inventory Control, etc., 11 On-line systems for Investment Advice and Management, Tax Minimization, etc., 12 Resources of interest to a home user., 13 Sports results., 14 Theatre, movies, and community events information., 15 Shopping information, prices, and advertisements., 16 Restaurants; good food guide., 17 Household magazine, recipes, book reviews, film reviews., 18 Holidays, hotels, travel booking., 19 Radio and TV programmes., 20 Medical assistance service., 21 Insurance information., 22 Computer Assisted Instruction (CAI)., , Network Type, , 0 to 1 Km, , Local Area Network (LAN), , 1 Km to 10 Km, , Metropolitan Area, Network (MAN), , 10 Km to 1000 Km, , Wide Area Network (WAN), , Above 1000 Km, , Internet, , Local Area Network (LAN), Networks used to interconnect computers in a single, room, rooms within a building or buildings on one site, are called Local Area Network (LAN). LAN transmits data, with a speed of several megabits per second (106 bits, per second). The transmission medium is normally coaxial cables., LAN (Fig 1) links computers, i.e., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited, geographical area because they must be connected by, a cable, which is quite expensive. People working in LAN, get more capabilities in data processing, work processing and other information exchange compared to standalone computers. Because of this information exchange, most of the business and government organisations are, using LAN., , 23 School homework, quizzes, tests., 24 Message sending service., 25 Directories., 26 Consumer reports., 27 Employment directories and Job opportunities., 28 Tax information and Tax assistance., 29 Journey planning assistance viz. Train, bus, plane, etc., , Major Characteristics of LAN, •, , every computer has the potential to communicate with, any other computers of the network, , •, , high degree of interconnection between computers, , Computer Networks may be classified on the basis of, geographical area in two broad categories., , •, , easy physical connection of computers in a network, , •, , inexpensive medium of data transmission, , 1 Local Area Network (LAN), , •, , high data transmission rate, , 2 Wide Area Network (WAN), , Types of Connection, , 30 Catalogue of Open University and Virtual University, courses., , 3 Metropolitan Area Network (MAN), , 170, , Peer to Peer: Peer to peer is an approach to computer, networking where all computers share equivalent, responsibility for processing data. Peer-to-peer, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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networking (also known simply as peer networking) differs, from client-server networking, where certain devices have, responsibility for providing or "serving" data and other, devices consume or otherwise act as "clients" of those, servers., , who sells the service to the users., 3 A MAN often acts as a high speed network to allow, sharing of regional resources. It is also frequently used, , Client server: The term client-server refers to a popular, model for computer networking that utilizes client and, server devices each designed for specific purposes. The, client-server model can be used on the Internet as well, as LAN., Advantages of LAN, •, , The reliability of network is high because the failure, of one computer in the network does not affect the, functioning for other computers., , •, , Addition of new computer to network is easy., , •, , High rate of data transmission is possible., , •, , Peripheral devices like magnetic disk and printer can, be shared by other computers., , Disadvantages of LAN, If the communication line fails, the entire network system, breaks down., Use of LAN, Followings are the major areas where LAN is normally, used, •, , File transfers and Access, , •, , Word and text processing, , •, , Electronic message handling, , •, , Remote database access, , •, , Personal computing, , •, , Digital voice transmission and storage, , to provide a shared connection to other networks using, a link to a WAN., Campus Area Network (CAN), A Campus Area Network or Corporate Area Network, (CAN) is a network is made up of an interconnection of, local area network within a limited geographical area. A, , Metropolitan Area Network (MAN), A Data network designed for a town or city. In terms of, geographic breadth, MANs are larger than, but smaller, than. MANs (Fig 2) are usually characterized by very, high-speed connections using or other digital media., Characteristic of MAN, 1 The network size falls intermediate between LANs, and WANs. A MAN typically covers an area of, between 5 and 50 km range. Many MANs cover an, area the size of a city, although in some cases MANs, may be as small as a group of buildings., 2 A MAN (like a WAN) is not generally owned by a, single organisation. The MAN, its communications, links and equipment are generally owned by either a, consortium of users or by a network service provider, , CAN (Fig 3) is larger than a local area network but smaller, than a Wide area Network, Wide Area Network (WAN), The term Wide Area Network (Fig 4) is used to describe a, computer network spanning a regional, national or global, area. For example, for a large company the head quarters, might be at Delhi and regional branches at Bombay,, Madras, Bangalore and Calcutta. Here regional centres, are connected to head quarters through WAN. The distance, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 171
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erate nationwide or even worldwide., , between computers connected to WAN is larger. Therefore, the transmission mediums used are normally telephone, lines, microwaves and satellite links., Characteristics of WAN, Followings are the major characteristics of WAN., 1 Communication Facility: For a big company, spanning over different parts of the country the, employees can save long distance phone calls and it, overcomes the time lag in overseas communications., Computer conferencing is another use of WAN where, users communicate with each other through their, computer system., 2 Remote Data Entry: Remote data entry is possible, in WAN. It means sitting at any location you can enter data, update data and query other information of, any computer attached to the WAN but located in, other cities., 3 Centralised Information: In modern computerised, environment you will find that big organisations go, for centralised data storage. This means if the, organisation is spread over many cities, they keep, their important business data in a single place. As, the data are generated at different sites, WAN permits collection of this data from different sites and, save at a single site., , •, , In LAN, the computer terminals and peripheral devices are connected with wires and coaxial cables., In WAN there is no physical connection. Communication is done through telephone lines and satellite links., , •, , Cost of data transmission in LAN is less because the, transmission medium is owned by a single, organisation. In case of WAN the cost of data transmission is very high because the transmission medium used is hired either telephone lines or satellite, links., , •, , The speed of data transmission is much higher in, LAN than in WAN. The transmission speed in LAN, varies from 0.1 to 100 megabits per second. In case, of WAN the speed ranges from 1800 to 9600 bits per, second (bps)., , •, , Few data transmission errors occur in LAN compared, to WAN. It is because in LAN the distance covered is, negligible., , Open Systems Interconnection (OSI), The Open Systems Interconnection (OSI) model is a reference tool for understanding data communications between any two networked systems. It divides the communications processes into seven layers. Each layer both, performs specific functions to support the layers above, it and offers services to the layers below it. The three, lowest layers focus on passing traffic through the network to an end system. The top four layers come into, play in the end system to complete the process., An Overview of the OSI Model (Fig 5), Application Layer (Layer 7): This layer interfaces directly to and performs common application services for, the application processes. The common application services provide semantic conversion between associated, application processes. Examples of common applica-, , Examples of WAN, 1 Ethernet: Ethernet developed by Xerox Corporation, is a famous example of WAN. This network uses coaxial cables for data transmission. Special integrated, circuit chips called controllers are used to connect, equipment to the cable., 2 Arpanet: The Arpanet is another example of WAN. It, was developed at Advanced Research Projects, Agency of U. S. Department. This Network connects, more than 40 universities and institutions throughout, USA and Europe., Difference between LAN and WAN, •, , LAN is restricted to limited geographical area of few, kilometers. But WAN covers great distance and op-, , 172, , tion services include the virtual file, virtual terminal (for, example, Telnet), and"Job transfer and Manipulation protocol" (JTM, standard ISO/IEC 8832), Presentation Layer (Layer 6): The Presentation layer, relieves the Application layer of concern regarding syntactical differences in data representation within the enduser systems. MIME encoding, encryption and similar, manipulation of the presentation of data are done at this, layer. An example of a presentation service would be, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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the conversion of an EBCDIC-coded text file to an ASCIIcoded file., Session Layer (Layer 5): The Session layer provides the, mechanism for managing the dialogue between end-user, application processes. It provides for either duplex or halfduplex operation and establishes check pointing, adjournment, termination, and restart procedures. This layer is, responsible for setting up and tearing down TCP/IP sessions., Transport Layer (Layer 4): The purpose of the Transport layer is to provide transparent transfer of data between end users, thus relieving the upper layers from, any concern with providing reliable and cost-effective, data transfer. The transport layer controls the reliability, of a given link. Some protocols are state ful and connection oriented. This means that the transport layer can, keep track of the packets and retransmit those that fail., The best known example of a layer 4 protocol is TCP., Network Layer (Layer 3): The Network layer provides, the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer. The Network layer performs network routing, flow control, segmentation/desegmentation, and error control functions., The router operates at this layer - sending data throughout the extended network and making the Internet possible, although there are layer 3 (or IP) switches. This is, a logical addressing scheme - values are chosen by the, network engineer. The addressing scheme is hierarchical., Data Link Layer (Layer 2): The Data link layer provides, the functional and procedural means to transfer data, between network entities and to detect and possibly correct errors that may occur in the Physical layer. The addressing scheme is physical which means that the addresses (MAC) are hard-coded into the network cards at, the time of manufacture. The addressing scheme is flat., Physical Layer (Layer 1): The physical layer defines, all electrical and physical specifications for devices. This, includes the layout of pins, voltages, and cable specifications. Hubs and repeaters are physical-layer devices., The major functions and services performed by the physical layer are:, •, , Establishment and termination of a connection to a, communications medium., , •, , Participation in the process whereby the communication resources are effectively shared among multiple users. For example, contention resolution and, flow control., , •, , Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications, , channel. These are signals operating over the physical, cabling - copper and fiber optic, for example. SCSI, operates at this level., Network Topology, The physical topology of a network refers to the configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which is the method used to pass information between workstations., Main Types of Physical Topologies, •, , LINEAR BUS, , •, , STAR, , •, , RING, , •, , TREE, , •, , MESH, , Linear Bus Topology, , A linear bus topology (Fig 6) consists of a main run of, cable with a terminator at each end. All nodes (file server,, workstations, and peripherals) are connected to the linear cable., Advantages of a Linear Bus Topology, •, , Easy to connect a computer or peripheral to a linear, bus., , •, , Requires less cable length than a star topology., , Disadvantages of a Linear Bus Topology, •, , Entire network shuts down if there is a break in the, main cable., , •, , Terminators are required at both ends of the backbone cable., , •, , Difficult to identify the problem if the entire network, shuts down., , •, , Not meant to be used as a stand-alone solution in a, large building., , Star Topology, A star topology (Fig 7) is designed with each node (file, server, workstations, and peripherals) connected directly, to a central network hub, switch, or concentrator, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 173
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Data on a star network passes through the hub, switch, or, concentrator before continuing to its destination. The hub,, switch, or concentrator manages and controls all functions of the network. It also acts as a repeater for the data, flow., This configuration is common with twisted pair cable;, however, it can also be used with coaxial cable or fiber, optic cable., Advantages of a Star Topology, •, , Easy to install and wire., , •, , No disruptions to the network when connecting or, removing devices., , •, , Easy to detect faults and to remove parts., , Disadvantages of a Star Topology, •, , Requires more cable length than a linear topology., , •, , If the hub, switch, or concentrator fails, nodes attached, are disabled., , •, , More expensive than linear bus topologies because, of the cost of the hubs, etc., , •, , There is no need for network server to control the, connectivity between workstations., , •, , Additional components do not affect the performance, of network., , •, , Each computer has equal access to resources., , Disadvantages of Ring Topology, •, , Each packet of data must pass through all the computers between source and destination., , •, , If one workstation or port goes down, the entire network gets affected., , •, , Network is highly dependent on the wire which connects different components., , •, , MAU's and network cards are expensive as compared, to Ethernet cards and hubs., , Tree or Expanded Star, A tree topology (Fig 9) combines characteristics of linear bus and star topologies. It consists of groups of starconfigured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of, an existing network, and enable schools to configure a, network to meet their needs., , Ring Topology, , Advantages of a Tree Topology, , The ring topology (Fig 8) is one which the network is a, loop where data is passed from one workstation to another., , •, , Point-to-point wiring for individual segments., , •, , Supported by several hardware and software vendors., , Advantages of Ring Topology, •, , This is very organized. Each node gets to send the, data when it receives an empty token. This helps to, reduces chances of collision. Also in ring topology all, the traffic flows in only one direction at very high, speed., , 174, , Disadvantages of a Tree Topology, •, , Overall length of each segment is limited by the type, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Disadvantages of Mesh topology, •, , There are high chances of redundancy in many of the, network connections., , •, , Overall cost of this network is way too high as compared to other network topologies., , of cabling used., , •, , •, , If the backbone line breaks, the entire segment goes, down., , Set-up and maintenance of this topology is very difficult. Even administration of the network is tough., , PROTOCOLS, , •, , More difficult to configure and wire than other topologies., , Network Protocol, , Advantages of Mesh topology, , A network protocol defines rules and conventions for, communication between network devices. Protocols for, computer networking all generally use packet switch techniques to send and receive messages in the form of, packets. Network protocols include mechanisms for devices to identify and make connections with each other,, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols, also support message acknowledgement and data compression designed for reliable and/or high-performance, network communication. Hundreds of different computer, network protocols have been developed each designed, for specific purposes and environments., , •, , Parameters of Protocol, , Mesh Topology, A network setup where each of the computers and, network devices are interconnected with one another,, allowing for most transmissions to be distributed, even, if one of the connections go down. This topology is not, commonly used for most computer networks as it is, difficult and expensive to have redundant connection to, every computer. However, this topology is commonly, used for wireless networks (Fig 10)., , •, , •, , Data can be transmitted from different devices, simultaneously. This topology can with stand high, traffic., Even if one of the components fails there is always, an alternative present. So data transfer doesn't get, affected., Expansion and modification in topology can be done, without disrupting other nodes., , 1 Physical cable or transmission media., 2 Number of bits transmitted on the media., 3 When to transmit the data on the network., 4 Volume of data to be transmitted., 5 Interact with a network with different cable type or topology., 6 Ensure that the message has been delivered intact, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 175
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Star Bus, Each computer connects to a, central connection device., , All information passes, through the, central network connection., , Each computer must be, close to the, central device., 100 meters, maximum, cable length., , Add a new, computer by, plugging in a, new cable, from, the, computer to, the connection device., , When one computer goes down,, the rest of the network is unaffected. If the connection device, goes down, then, the network is, down., , More expensive, of, the, simple topologies,, it requires, costly, connection dev i c e ., Usually, cheaper, than a hybrid network., , Uses twisted, pair cable., , To add a, c o m p u t e r,, you, must, shut down, the network, and disconnect, the, cable from, the existing, computers., , If one computer, malfunctions, the, entire network, goes down., , A cheaper, network, s i n c e, there is, usually, one continuous, copper, cable., , Single continuous cable connects the devices., , Cable between the, computers, must be broken to add a, new computer, so the, network is, down until, the new device is back, online., , If there's a break, in the cable or an, error in the network, information, continues to transfer through the, rest of the ring until reaching the, point of the break., This, makes, troubleshooting, easy., , Up to 24, computers, per network., , Requires large, amounts, of, cable. No more, than, 100, meters from, the computer to, the connection, device., , Bus, Single, cable connects everything., , One, computer at a time, sends information. Information goes, along, the, cable and the, computer accesses the information off, the cable., , Connect the, cable from, one, computer to the, next and so, on to the end., , Information, goes in one, direction, around the, ring, and, passes along, the ring until it, reaches the, correct computer., , Computers, are located, close to each, other., , A terminator, is placed at, each end of, the network., , Terminator is, required, at, each end of the, cable., Uses coaxial or, twisted pair cabling., , Ring, S i n g l e, cable configured in a, ring., , 176, , Setup, is, easy. There, is no connector., The ring has, no beginning, and no end., , One of the, more expensive, topologies, due, to, high cable, costs., , Requires more, cabling than, other topologies., Uses twisted, pair., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Hybrid, Mesh, Combines, two or more, different, structures., , Often used, across long, distances. Information, transfer can, happen in different ways,, depending on, the other topologies., , Often created, when, expanding an, existing network. Can, use a variety, of connection, devices., , Connection, devices, make combining different networks, and different, topologies, easy., , and in a proper manner., List of Network Protocols, 1 TCP/IP: Transmission Control Protocol / Internet Protocol is an industry standard protocol widely used. It is, used for inter operating among different types of computers. Almost all types of networks support TCP/IP. It is, the protocol used by the Internet. It uses a 32 - bit addressing scheme., IP Address, IP defines an addressing scheme that is independent of, the underlying physical address (e.g. 48-bit MAC address). IP specifies a unique 32-bit number for each host, on a network., , Troubleshooting is, most difficult in, this topology because of the variety of technologies., , Expens i v e ,, large,, and usually complicated., , Cabling depends on the, types of networks., Can use twisted, pair and coaxial, cable., Also incorporates fiber optic, cabling over, long distances., , FTP is built on a client-server architecture and uses separate control and data connections between the client and, the server. FTP users may authenticate themselves using, a clear-text sign-in protocol, normally in the form of a, username and password, but can connect anonymously, if the server is configured to allow it., For secure transmission that hides (encrypts) the, username and password, and encrypts the content, FTP, is often secured with SSL/TLS ("FTPS"). SSH File Transfer Protocol (SFTP) is sometimes also used instead., 4 SMTP, Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across, Internet Protocol (IP) networks., , This number is known as the Internet Protocol Address,, the IP Address or the Internet Address. These terms are, interchangeable. Each packet sent across the internet, contains the IP address of the source of the packet and, the IP address of its destination., , While electronic mail servers and other mail transfer, agents use SMTP to send and receive mail messages,, user-level client mail applications typically only use, SMTP for sending messages to a mail server for relaying., , 2 UDP - User Datagram Protocol - is a simple OSI transport layer protocol for client/server network applications, based on Internet Protocol (IP). UDP is the main alternative to TCP and one of the oldest network protocols in, existence, introduced in 1980. UDP is often used in, videoconferencing applications or computer games specially tuned for real-time performance., , For receiving messages, client applications usually use, either the Post Office Protocol (POP) or the Internet, Message Access Protocol (IMAP) or a proprietary system (such as Microsoft Exchange or Lotus Notes/, Domino) to access their mail box accounts on a mail, server., 5 Telnet, , 3 FTP: File Transfer Protocol (FTP) is a standard network protocol used to transfer files from one host or to, another host over a TCP-based network, such as the, Internet., , Telnet is a network protocol used on the Internet or local, area networks to provide a bidirectional interactive textoriented communication facility using a virtual terminal, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 177
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connection. User data is interspersed in-band with Telnet, control information in an 8-bitbyte oriented data connection over the Transmission Control Protocol (TCP)., Telnet provided access to a command-line interface (usually, of an operating system) on a remote host. Most, network equipment and operating systems with a TCP/, IP stack support a Telnet service for remote configuration (including systems based on Windows NT). Because, of security issues with Telnet, its use for this purpose, has waned in favour of SSH., 6 HTTP, , Networking Components, •, , Gateway: A device sitting at a network node for, interfacing with another network that uses different, protocols. Works on OSI layers 4 to 7., , •, , Router: A specialized network device that determines, the next network point to which it can forward a data, packet towards the destination of the packet. Unlike, a gateway, it cannot interface different protocols., Works on OSI layer 3., , •, , Switch: A device that allocates traffic from one, network segment to certain lines (intended, destination(s)) which connect the segment to another, network segment. So unlike a hub a switch splits the, network traffic and sends it to different destinations, rather than to all systems on the network. Works on, OSI layer 2., , •, , Bridge: A device that connects multiple network, segments along the data link layer. Works on OSI, layer 2., , •, , Hub: It connects multiple Ethernet segments together, making them act as a single segment. When using a, hub, every attached device shares the same, broadcast domain and the same collision domain., Therefore, only one computer connected to the hub, is able to transmit at a time., , The Hypertext Transfer Protocol (HTTP) is an application, protocol for distributed, collaborative, hypermedia, information systems. HTTP is the foundation of data, communication for the World Wide Web., Hypertext is a multi-linear set of objects, building a, network by using logical links (the so-called hyperlinks), between the nodes (e.g. text or words). HTTP is the, protocol to exchange or transfer hypertext., 7 SSH File Transfer Protocol, In computing, the SSH File Transfer Protocol (also, Secure File Transfer Protocol, Secure FTP, or SFTP) is, a network protocol that provides file access, file transfer,, and file management functionalities over any reliable, data stream., , Depending on the network topology, the hub provides, a basic level 1 OSI model connection among the, network objects (workstations, servers, etc.). It, provides bandwidth which is shared among all the, objects, compared to switches, which provide a, connection between individual nodes., , It was designed by the Internet Engineering Task Force, (IETF) as an extension of the Secure Shell Protocol, (SSH) version 2.0 to provide secure file transfer, capability, but is also intended to be usable with other, protocols., The IETF of the Internet Draft states that even though, this protocol is described in the context of the SSH-2, protocol, it could be used in a number of different, applications, such as secure file transfer over Transport, Layer Security (TLS) and transfer of management, information in VPN applications., This protocol assumes that it is run over a secure, channel, such as SSH, that the server has already, authenticated the client, and that the identity of the client, user is available to the protocol., 8 Post Office Protocol, In computing, the Post Office Protocol (POP) is an, application-layer Internet standard protocol used by local, e-mail clients to retrieve e-mail from a remote server, over a TCP/IP connection. POP and IMAP (Internet, Message Access Protocol) are the two most prevalent, Internet standard protocols for e-mail retrieval., Virtually all modern e-mail clients and servers support, both. The POP protocol has been developed through, several versions, with version 3 (POP3) being the current, standard. Most webmail service providers such as, Hotmail, Gmail and Yahoo! Mail also provide IMAP and, POP3 service., , 178, , •, , Repeater: A device to amplify or regenerate digital, signals received while sending them from one part of, a network into another. Works on OSI layer 1., , •, , Modem (MoDem): A device that modulates an analog, "carrier" signal (such as sound), to encode digital, information, and that also demodulates such a carrier, signal to decode the transmitted information, as a, computer communicating with another computer over, the telephone network, , Types of MODEM, External Modem: This is a modem separated from the, system unit in the computer case. It is connected to the, serial port of the computer by means of a cable. It is, connected to the telephone wall jack by another cable., Internal Modem: An internal modem is a circuit board, (a modem card) that can be added to the system unit of, the computer. It takes one of the expansion slots., Wired Modem / Standard Modem, Most modem’s used today are called standard modems., These modems are usually operated by commands, entered from a microcomputer keyboard. Users control, the functions (dialling, etc.) of a modem through the, keyboard. Modems may use different command, languages to control their functions,, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Wireless Modems: Wireless modems transmit the data, signals through the air instead of by using a cable. They, sometimes are called a radiofrequency modem. This type, of modem is designed to work with cellular technology,, and wireless local area networks. Wireless modems are, not yet perfected, but the technology is rapidly improving., ADSL Modem, Asymmetric Digital Subscriber Line, ADSL (Fig 11) is a, type of DSL broadband communications technology used, for connecting to the Internet. ADSL allows more data to, be sent over existing copper telephone lines POTS, when, compared to traditional modem lines. A special filter, called, a micro filter, is installed on a subscriber's telephone line, to allow both ADSL and regular voice (telephone) services, to be used at the same time. ADSL requires a special, ADSL modem and subscribers must be in close, geographical locations to the provider's central office to, receive ADSL service. Typically this distance is within a, radius of 2 to 2.5 miles. ADSL supports data rates of from, 1.5 to 9 Mbps when receiving data (known as the downstream rate) and from 16 to 640 Kbps when sending data, (known as the up- stream rate)., , Ethernet NICs plug into the system bus of the PC and, include jacks for network cables, while WI-FI NICs contain built-in transmitters / receivers (transceivers). In new, computers, many NICs are now pre-installed by the manufacturer. All NICs feature a speed rating such as 11 Mbps,, 54 Mbps or 100 Mbps that suggest the general performance of the unit., Network Cables Standards, Cable is the medium through which information usually, moves from one network device to another. There are, several types of cable which are commonly used with, LANS. In some cases, a network will utilize only one, type of cable, other networks will use a variety of cable, types. The type of cable chosen for a network is related, to the network's topology, protocol, and size. Understanding the characteristics of different types of cable and, how they relate to other aspects of a network is necessary for the development of a successful network., Cable standards, A wide range of cabling types are been used to run Ethernet, systems. Therefore, different types of cabling standards, are being used for the networks involved in connecting, devices together using different types of cabling system., , Network Interface Card (NIC), NIC (Fig. 12) provides the hardware interface between a, computer and a network. A NIC technically is network, adapter hardware in the form factor of an add-in card such, as a PCI or PCMCIA card. Some NIC cards work with, wired connections while others are wireless. Most NICs, support either wired Ethernet or WI-FI wireless standards., 12, , Coaxial cable (Fig 13) is the kind of copper cable used by, companies between the community antenna and user, homes and businesses. Coaxial cable is sometimes used, by telephone companies from their central office to the, telephone poles near users. It is also widely installed for, use in business and corporation and other types of., Coaxial cable is called "coaxial" because it includes one, physical that carries the signal surrounded (after a layer, of insulation) by another concentric physical channel,, both running along the same axis. The outer channel, serves as a ground. Many of these cables or pairs of, coaxial tubes can be placed in a single outer sheathing, and, with repeaters, can carry information for a great distance., 10BASE-T Cable Standard: 10Base-T is one of the, Ethernet standards for cabling in a network environment., 10BaseT uses a twisted pair cable with a maximum length, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 179
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of 100 meters. Standard 10BaseT operates at 10 Mbps. It, is commonly used in a star topology., 10BASE-FL Cable Standard: 10BaseFL is a fibber optic, cable standard designed to run at 10 Mbps. It is similar, to 10Base-T, though the media type is fibber. For use up, to 2000 meters., 100BASE-TX Cable Standard: 100 Mbps Fast Ethernet, over category 5 twisted pair cable. Maximum cable length, of 100 meters., 100BASE-FX Cable Standard: 100 Mbps Fast Ethernet, standard over fibber cable. Can transmit data up to 2000, meters., 1000BASE-T Cable Standard: Gigabit Ethernet over, twisted pair copper wires. Transmit up to 1000 Mbps., 100 meter maximum cable length. Cat5 or better required, (Cat6 cabling recommended)., 1000BASE-CX Cable Standard: Gigabit Ethernet over, a special copper twinax cable. Up to 25 meters in length., Typically used in a wiring closet or data center as a short, jumper cable., , adjoining wires., The advantage of using twisted pair cables are, •, , It is lighter, thinner and more flexible, , •, , Easy to install, , •, , It is in expensive, , There are two varieties of twisted pair cabling, they are, •, , Unshielded Twisted Pair (UTP), , •, , Shielded Twisted Pair (STP), , Unshielded twisted pair (UTP), Unshielded twisted pair (Fig 14) cabling consists of two, unshielded wires twisted around each other that contain, no shielding. It is commonly used in the telephone wires, and is common for computer networking because of high, flexibility of the cables. It is a plastic connector that looks, like a large telephone-style connector. The standard connector for unshielded twisted pair cabling is RJ-45 connector., , 1000BASE-SX Cable Standard: Gigabit Ethernet using, a short-wavelength laser device over multimode fibber, optic cable. 50 μm core (max 300 meters) or 62.5 μm, core (max 500 meters). 1000Mbps maximum transfer, speed., 1000BASE-LX Cable Standard: Gigabit Ethernet using, long-wavelength laser transmitters over fibber optic, cable. Up to 3,000 meters. Uses single mode fibber and, requires SC connectors for terminating the cable., 10 GBASE-SR Cable Standard: 802.3ae standard. 33, meters for 62.5μm fibber optic cable, 300 meters for, 50μm cables. 10 Gbps (Gigabit per second) transfer rate., 10 GBASE-LR Standard: 10 Gbps transfer rate. 10, kilometres maximum distance. Fibber optic cable., , UTP has five categories of cable standards defined by the, Electronic Industries Association and Telecommunications, Industry Association (commonly known as EIA/TIA). The, five categories of unshielded twisted pair are:, Categories of Unshielded Twisted Pair, , 10 GBASE-ER Standard: 10 Gbps transfer rate. 40, kilometres maximum cable length. Fibber optic cable., , In order to manage the network cabling, you need to be, familiar with the standards that may be used on modern, networks. The categories of the unshielded twisted pair, cable are described below., , Media types, , Category 1, , A cable is a device which contains a number of signal, conductors usually in the form of separate wires. It is the, medium through which information usually moves from, one system to another through the network. There are, several types of cable which are commonly used with, the local area network. In some cases, a network utilizes, only one types of cable, whereas other network uses a, variety of cable types. The type of cable chosen for a, network is related to network topology, protocol and size., , •, , It is a form of UTP that contains two pairs of wire., , •, , CAT is suitable for voice communications but not for, data., , •, , It can carry up to 128 kilobits per second (Kbps) of, data., , •, , Twisted Pair, , It is usually used for telephone wire Data rate - 1, Mbps. This type of wire is not capable of supporting, computer network traffic and is not twisted., , Category 2, , Twisted pair cable is the most common type of network, medium used in LAN today. A transmission media consist, of colour coded pairs of two shielded insulated copper, wires which are arranged in a spiral pattern. The spiral, pattern is an important aspect of twisted - pair cables in, order to minimize cross talk of interference between, , 180, , •, , It contains four wire pairs and can carry up to 4 Mbps, of data., , •, , CAT 2 is rarely found on modern networks., , •, , Category 2 or CAT 2 is capable of transmitting data, up to 4 Mbps. This of cable is seldom used., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Category 3, •, , CAT 3 made up of four twisted - pair wires, each twist, is three times per foot. It is certified to transmit data, up to 10 Mbps., , •, , CAT 3 has typically been used for 10 Mbps Ethernet, or 4 Mbps Token Ring networks., , •, , The CAT 3 cabling is gradually replaced with CAT5 to, accommodate higher throughput., , Category 4, •, , CAT 4 is made up of four twisted-pair wires, specialized to transmit data up to 16 Mbps and is rarely is, used in new installations., , •, , CAT 4 may be used for 16Mbps Token Ring or 10, Mbps Ethernet networks. It is guaranteed for signals, as high as 20 MHz and Provides More protection, against crosstalk and attenuation than CAT1, CAT2,, orCAT 3., , The extra covering in shielded twisted pair wiring protects, the transmission line from leaking into or out of the cable., STP cabling often is used in networks, especially fast, data rate Ethernets., Fiber Optic Cable (Fig 16), , Category 5, •, , CAT 5 is the most popular twisted pair Ethernet cabling designed for high signal integrity which is in common use today., , •, , CAT 5 contains four wire pairs and supports up to, 100 Mbps throughout., , •, , It is the most popular form of UTP for new network, installations and upgrades to Fast Ethernet., , •, , In addition to 100 Mbps Ethernet, CAT 5 wiring can, support other fast networking technologies., , •, , It is popular because it is both affordable and high, speed for today's local area networks Cat 5 cables, are often used in structured cabling for computer, networks such as fast Ethernet., , Category 6, •, , •, , •, , •, , A technology that uses glass (or plastic) threads (fibers), to transmit. A fiber optic cable consists of a bundle of, glass threads, each of which is capable of transmitting, messages on to light waves., Fibre optics has several advantages over traditional metal, lines:, •, , CAT 6 cable was originally designed to support gigabit Ethernet. It is similar to CAT 5 wire, but contains a, physical separator between the four, , Fibre optic cables have a much greater than metal, cables. This means that they can carry more data., , •, , Fibre optic cables are less susceptible than metal, cables to interference., , Twisted copper wires pairs to further reduce the electromagnetic interference., , •, , Fibre optic cables are much thinner and lighter than, metal wires., , It is a twisted-pair cable that contains four wire pairs,, each wrapped in foil insulation. Additional foil insulation covers the bundle of wire pairs, and a fire-resistant plastic sheet covers the second foil layer., , •, , Data can be transmitted (the natural form for data), rather than analogically., , The foil insulation provides excellent resistance to, crosstalk and enables CAT 6 to support at least six, times the throughput supported by regular CAT 5., When the CAT 6 is used as a patch cable, it is usually, terminated in RJ-45 Electrical connectors., , Shield Twisted Pair (Fig 15), A type of copper telephone wiring in which each of the two, copper wires that are twisted together are coated with an, insulating coating that functions as a ground for the wires., , The main disadvantage of fibre optics is that the cables, are expensive to install. In addition, they are more fragile, than wire and are difficult to splice., In addition, telephone companies are steadily replacing, traditional telephone lines with fibre optic cables. In the, future, almost all communications will employ fibre optics., Straight Cable, A straight cable (Fig 17) is to connect different type of, devices. This type of cable will be used most of the time, and can be used to:, , IT & ITES : COPA - (NSQF Level - 4)- Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 181
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Rollover Cable (Fig 19), 19, , 1 Connect a computer to a switch/hub's normal port., 2 Connect a computer to a cable/DSL modem's LAN, port., 3 Connect a router's WAN port to a cable/DSL modem's, LAN port., 4 Connect a router's LAN port to a switch/hub's uplink, port. (Normally used for expanding network), 5 Connect 2 switches/hubs with one of the switch/hub, using an uplink port and the other one using normal, port., If you need to check how straight cable looks like, it's, easy. Both sides (side A and side B) of cable have wire, arrangement with same colour., Crossover Cable, A crossover cable (Fig 18), it's usually used to connect, same type of devices. A crossover cable can be used to:, , 1 Connect 2 computers directly., 2 Connect a router's LAN port to a switch/hub's normal, port. (Normally used for expanding network)., 3 Connect 2 switches/hubs by using normal port in both, switches/hubs., In you need to check how crossover cable looks like,, both side (side A and side B) of cable have wire arrangement with following different colour., , 182, , Rollover cable (also known as Cisco Console Cable or a, Yost Cable) is a type of cable that is often used to connect a computer terminal to a router's port. This cable is, typically flat (and has a light blue colour) to help distinguish it from other types of network cabling. It gets the, name rollover because the pin outs on one end are reversed from the other, as if the wire had been rolled over, and you were viewing it from the other side., Connectors, The media connectors are the physical devices that help, to transfer the data between the systems., RJ11: Registered Jack-11 (Fig 20) a four- or six-wire, used primarily to connect telephone equipment. RJ-11, connectors are also used to connect some types of some, types of Local area network., 20, , RJ45: RJ45 (Fig 21) connectors feature eight pins to which, the wire strands of a cable interface electrically. Standard, RJ-45 pinouts define the arrangement of the individual wires, needed when attaching connectors to a cable., ST: ST stands for Straight Tip (Fig 22) - a quick release, bayonet style developed by AT&T. STs were predominant, in the late 80s and early 90s., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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21, , ST Connectors are among the most commonly used fiber, optic connectors in networking applications. They are cylindrical with twist lock coupling, 2.5mm keyed ferrule. ST, connectors are used both short distance applications and, long line systems., SC: SC stands for Subscriber Connector (Fig 23) - a, general purpose push/pull style Connector developed by, NTT. SC has an advantage in keyed duplexibility to support send/receive channels., SC Connectors are frequently used for newer Network, applications. The SC is a snap-in connector that is widely, used in single mode systems for its performance. The, SC connector is also available in a Duplex configuration., They offer low cost, simplicity, and durability. SC connectors provide for accurate alignment via their ceramic ferrules., The square, snap-in connector latches with a simple, push-pull motion and is keyed. They feature a 2.5mm, Ferrule and molded housing for protection. Typical matched, SC connectors are rated for 1000 mating cycles and have, an Insertion Loss of 0.25 dB., , USB: The USB 2.0 Standard-A type of USB plug is a, flattened rectangle which inserts into a "downstream-port", receptacle on the USB host, or a hub, and carries both, power and data. This plug is frequently seen on cables, that are permanently attached to a device, such as one, connecting a keyboard or mouse to the computer via, USB connection., A Standard-B plug-which has a square shape with bevelled exterior corners-typically plugs into an "upstream, receptacle" on a device that uses a removable cable,, e.g. a printer. A Type B plug delivers power in addition to, carrying data. On some devices, the Type B receptacle, has no data connections, being used solely for accepting, power from the upstream device. This two-connector-type, scheme (A/B) prevents a user from accidentally creating, an Electrical loop., BNC: Bayonet Neill Concelman (Fig 25) connector,, (sometimes erroneously called a British Naval Connector, or Bayonet Nut Connector, a type of connector used with, coaxial cable such as the RG-58 A/U cable used with the, 10Base2. The basic BNC connector is a male type, mounted at each end of a cable., , LC: LC stands for Lucent Connector (Fig 24). The LC is, a small form factor fiber optic connector., The LC Connector uses a 1.25 mm ferrule, half the size of, the ST. Otherwise, it is a standard ceramic Ferrule connector. The LC has good performance and is highly favoured, for single mode., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 183
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This connector has a center pin connected to the center, cable conductor and a metal tube connected to the outer, cable shield. A rotating ring outside the tube locks the, cable to any female connector., BNC T-connectors (used with the 10Base-2 system) are, female devices for connecting two cables to a NIC. A, BNC barrel connector allows connecting two cables together., BNC connectors can also be used to connect some, monitor, which increases the accuracy of the signals sent, from the adapter., Crimping Tool: A crimping tool (Fig 26) is a tool designed to crimp or connect a connector to the end of a, cable. For example, network cables and phone cables, are created using a crimping tool to connect the RJ45 and, RJ11 connectors to the end of the cable. In the picture to, the right, is an example of what a crimping tool looks like., This shows a tool capable of crimping both RJ-11 and RJ45 connectors., , 5 Arrange the untwisted wires in a row, placing them, into the position, running from right to left, in which, they will go into the RJ-45 connector:, •, , Orange with a white stripe, , •, , Orange, , •, , Green with a white stripe, , •, , Blue, , •, , Blue with a white strip, , •, , Green, , •, , Brown with a white stripe, , •, , Brown, , 6 Trim the untwisted wires to a suitable length by holding the RJ-45 connector next to the wires. The insulation on the cable should be just inside the bottom, of the RJ-45 connector. The wires should be trimmed, so that they line up evenly with the top of the RJ-45, connector., •, , Trim the wires in small increments, checking frequently to ensure a correct fit. It's better to cut the, untwisted wires a few times than have to go back, and start all over again because you trimmed off, too much., , 7 Insert the wires into the RJ-45 connector, making sure, that they stay aligned and each color goes into its, appropriate channel. Make sure that each wire goes, all the way to the top of the RJ-45 connector. If you, don't make these checks, you will find that your newly, crimped RJ-45 connector is useless., 8 Use the crimping tool to crimp the RJ-45 connector, to the cable by pressing the jacket and cable into the, connector so that the wedge at the bottom of the connector is pressed into the jacket., Re crimp the cable once more to ensure proper connection., , How to Crimp RJ45, 1 Strip 1 to 2 inches (2.5 to 5.1 cm) of the outer skin at, the end of the cable wire by making a shallow cut in, the skin with a utility knife. Run the knife around the, cable, and the jacket should slide off easily. There will, be 4 pairs of twisted wires exposed, each of them a, different color or colour combination., Orange-white striped and solid orange, Green-white striped and solid green, Blue-white striped and solid blue, Brown-white striped and solid brown, 2 Fold each pair of wires backwards to expose the core, of the cable., 3 Cut off the core and discard., , 9 Follow the instructions above to crimp an RJ-45 connector to the opposite end of the cable, 10 Use a cable tester to assure that your cable is working properly when both ends are crimped., Cable Tester (Fig 27), When connected to an Ethernet cable, a network cable, tester tells if the cable is capable of carrying an Ethernet, signal. If the cable carries the signal, this indicates that, all the circuits are closed, meaning that electric current, can move unimpeded through the wires, and that there, are no short circuits, or unwanted connections, in the wire., Network cable testers vary in complexity and price, but a, basic tester consists of a source of electrical current, a, measuring device that shows if the cable is good, and a, connection between the two, usually the cable itself., , 4 Straighten the twisted wires using 2 pair of tweezers., Grasp a wire beneath a bend with 1 pair of tweezers,, and use the other pair to gently straighten the bend., The straighter your wires, the easier your job will be, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, 184, , Copyright @ NIMI Not to be Republished
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Switch, A Network Switch (Fig 28) is a small hardware device, that joins multiple computers together within one Local, Area Network. Technically, network switches operate at, layer two (Data Link Layer) of the OSI., 28, , Computer networks use Ethernet cables to allow computers in the network to "talk" to each other. An Ethernet, cable has eight wires that are arranged in four pairs. For, current to flow correctly, the wire pairs must be connected, in the proper order., A network cable tester can identify if the wires are paired, correctly. It can also show if there is a break in the insulation, a situation which allows crosstalk between two, wires that should not be connected. The tester can also, tell whether the cable has the proper level of resistance., A network cable tester can be a simple apparatus that, merely identifies whether current flows through the cable,, or it may be a professional-level, complex device that, gives additional information that helps identify the problem., Professional-level network cable testers may not only, tell if an open circuit exists, but may identify where the, break is located. Some also identify the gauge of wire, used and can generate their own signal to test for interference., How to Check with the Tester, , Network switches appear nearly identical to hub, but a, switch generally contains more intelligence (and a slightly, higher price tag) than a hub. Unlike hubs, network switches, are capable of inspecting data packet as they are received,, determining the source and destination device of each, packet, and forwarding them appropriately., By delivering messages only to the connected device intended, a network switch conserves bandwidth and offers, generally better performance than a hub., Availability of Switches, 1 8 Port Switches, 2 16 port switches, 3 24 port switches, 4 32 port switches, Hub: A Hub (Fig 29) is a small, simple, inexpensive, device that joins multiple computers together. Many, network hubs available today support the Ethernet, standard. Other types including USB hubs also exist, but, Ethernet is the type traditionally used in home networking., To network a group of computers using an Ethernet hub,, 29, , 1 Turn on your network cable tester., 2 Plug one end of the Ethernet cable you are trying to, test into the "IN" Ethernet input on the network cable, tester., 3 Plug the other end of your Ethernet cable you are, trying to test into the "OUT" input on the network cable, tester., 4 Press the "Test" button. The network cable tester will, send a signal across the Ethernet cable. If the signal, gets from one end of the cable to the other, a green, light will appear on the device, letting you know that, the test was successful. If the signal does not get, from one end of the cable to the other, a red light will, appear on the device, letting you know that the test, was not successful and that the cable is bad., , first connect an Ethernet cable into the unit, and then, connect the other end of the cable to each computer's, NIC. All Ethernet hubs accept the RJ45 connectors of standard Ethernet cables., Ethernet hubs vary in the speed (network data rate or, bandwidth they support. Some years ago, Ethernet hubs, offered only 10 Kbps rated speeds. Newer types of hubs, offer 100 Mbps Ethernet. Some support both 10 Mbps, and 100 Mbps (so-called dual-speed or 10/100 hubs)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 185
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Routers, Routers (Fig 30) are physical devices that join multiple, wired or wireless networks together. Technically, a wired, or wireless router is a Layer 3 gateway, meaning that the, wired/wireless router connects networks (as gateways do),, and that the router operates at the network layer of the, OSI model., , monthly fee for this equipment that is added to your ISP, account billing., In addition to serving individuals, ISPs also serve large, companies, providing a direct connection from the, company's networks to the Internet. ISPs themselves, are connected to one another through Network Access, Point (NAPs). ISPs may also be called IAPs (Internet, Access Provider)., State Owned ISP's, •, , BSNL - Servicing all of India except Mumbai and, Delhi. Triple-play Broadband Services provided by, ADSL and VDSL. Also providing internet services over, GPRS, 3G, as well as WiMax, , •, , MTNL - Servicing Mumbai and Delhi. Triple-play, Broadband Services provided by ADSL under the "TriBand" brand. Also providing GPRS and 3G internet, services., , Private Owned nationwide ISP's, •, , Airtel - ADSL, GPRS, 3G & 4G LTE, , Home networkers often use an Internet Protocol (IP), wired or wireless router, IP being the most common OSI, network layer protocol. An IP router such as a DSL or, cable modem router joins the home's LAN to the WAN, of the Internet., , •, , Skynet Broadband - Internet Service Provider, , •, , Aircel - GPRS & 3G, , •, , Hathway - Broadband over Cable, , •, , Idea - GPRS & 3G, , Bridges, , •, , MTS India - CDMA/EV-DO, , A bridge (Fig 31) device filters data traffic at a network, boundary. Bridges reduce the amount of traffic on a LAN, by dividing it into two segments., , •, , O-Zone Networks Private Limited - Pan - India Public Wi-Fi hotspot provider, , •, , Reliance Communications - ADSL, GPRS & 3G,, Metro-Ethernet, CDMA/EV-DO, Wimax, , •, , Reliance Industries - LTE (to be launched), , •, , Sify - Broadband over cable, , •, , Tata DoCoMo - GPRS & 3G, , •, , Tata Indicom - ADSL, CDMA/EV-DO, Metro-Ethernet,, WiMax, , •, , Vodafone - GPRS & 3G, , 31, , Bridges operate at the data link layer (Layer 2) of the OSI, model. Bridges inspect incoming traffic and decide whether, to forward or discard it. An Ethernet bridge, for example,, inspects each incoming Ethernet frame - including the, source and destination MAC addresses, and sometimes, the frame size - in making individual forwarding decisions., ISP: Internet Service Provider, it refers to a company that, provides Internet services, including personal and business access to the internet. For a monthly fee, the service provider usually provides a software package,, Username, password and access phone number., Equipped with a modem you can then log on to the, Internet and browse the world wide web and USENET, and send and receive email For broadband access you, typically receive the broadband modem hardware or pay a, , 186, , NSP: Network Service Providers (NSP) is a business or, organization that sells bandwidth or network access by, providing direct Internet backbone access to the Internet, and usually access to its Network Access Point (NAPs)., Network service providers may consist of Telecommunications companies, data carriers, wireless communications providers, Internet service provider, and Cable television operators offering high-speed Internet access., Dial up: Dial-up access is really just like a phone connection, except that the parties at the two ends are computer devices rather than people. Because dial-up access, uses normal telephone lines, the quality of the connection, is not always good and data rate are limited., In the past, the maximum data rate with dial-up access, was 56 Kbps (56,000 bits per second), but new technologies such as ISDN are providing faster rates., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Broadband: The term broadband refers to a telecommunications signal or device of greater Bandwidth (signal processing), in some sense, than another standard or usual, signal or device (and the broader the band, the greater the, capacity for traffic)., Wireless (Wi-Fi): Wireless broadband is high-speed, Internet service via wireless technology. Wireless broadband is available in Internet cafés, local "hot spots" within, many cities, private businesses and many homes., The advantage of wireless broadband is that the computer receiving the Internet signal need not be tethered, by an Ethernet or network cable to the broadband modem or router., , A wireless broadband modem receives the service and, transmits it via radio waves to the immediate surrounding area. Any computer equipped with wireless capacity, within receiving distance can pick up the signal, making, the Internet 'portable.' The most common way to take, advantage of wireless broadband is by using a laptop, computer., Mobile Broadband: The term mobile broadband refers, to high-speed wireless Internet connections and services, designed to be used from arbitrary locations., Cellular networks normally provide broadband connections suitable for mobile access. The technologies in use, today fall into two categories -3G (third generation cell, networks) and 4G (fourth generation)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 187
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.70, , Introduction to TCP/IP, Objectives : At the end of this lesson you shall be able to, • explain TCP/IP, addresses and subnets., Introduction to TCP/IP : TCP and IP were developed by, Department of Defense (DOD) research project to connect, a number different networks designed by different vendors, into a network of networks (the “Internet”). It was initially, usccessful because it delivered a few basic services that, everyone needs (file transfer, electronic mail, remote, logon) across a very large number of client and server, systems. Several computers in a small department can, use TCP/IP (along with other protocols) on a single LAN., The IP component provides routing from the department, to the enterprise network, then to regional networks, and, finally to the global internet. On the battlefield a, communications network will sustain damage, so the, DOD designed TCP/IP to be robust and automatically, recover from any node or phone failure. This design, allows the construction of very large networks with less, central management. However, because of the automatic, recovery, network problems can go undiagnosed and, uncorrected for long periods of time., As with all other communications protocol, TCP/IP is, composed of layers:, IP is responsible for moving packet of data from node to, node. IP forwards each packet based on a four byte, destination address (the IP number). The Internet, authorities assign ranges of numbers to different, organisations. The organisations assign groups of their, numbers to departments. IP operates on gateway, machines that move data from department to organisation, to region and then around the world., TCP is responsible for verifying the correct delivery of, data from client to server. Data can be lost in the, intermediate network. TCP adds support to detect errors, or lost data and to trigger retransmission until the data is, correctly and completely received., Sockets is a name given to the package of subroutines, that provide access to TCP/IP on most systems., The Internet Protocol was developed to create a Network, of Networks (the “Internet”). Individual machines are first, connected to a LAN (Ethernet or Token Ring). TCP/IP, shares the LAN with other users (a Novell file server,, Windows for Workgroups peer systems). One device, provides the TCP/IP connection between the LAN and, the rest of the world. (Refer Fig 1), To insure that all types of systems from all vendors can, communicate, TCP/IP is absolutely standardised on the, LAN. However, larger networks based on long distances, and phone lines are more volatile. In US, many large, corporations would wish to reuse large internal networks, based on IBM’s SNA. In Europe, the national phone, 188, , companies traditionally standardize on X.25. However,, the sudden explosion of high speed microprocessors,, fiber optics and digital phone systems has created a burst, of new options: ISDN, frame relay, FDDI, Asynchronous, Transfer Mode (ATM). New technologies arise and, become obsolete within a few years. With cable TV and, phone companies competing to built the National, Information Superhighway, no single standard can govern, citywide, nationwide, or worldwide communications., The original design of TCP/IP as a Network of Networks, fits nicely within the current technological uncertainty., TCP/IP data can be sent across a LAN or it can be carried, within an internal corporate SNA network or it can, piggyback on the cable TV service. Furthermore,, machines connected to any of these networks can, communicate to any other network through gateways, supplied by the network vendor., Addresses : Each technology has its own convention for, transmission messages between two machines within, the same network. On a LAN, messages are sent between, machines by supplying the six byte unique identifier (the, “MAC” address). In an SNA network, every mahine has, Logical Units with their own network address. DECNET,, Appletalk and Novell IPX all have a scheme for assigning, numbers to each local network and to each workstation, attached to the network., On top of these local or vendor specific network addresses,, TCP/IP assigns a unique number to every workstation in, the world. This “IP number” is a four byte value that, by, convention, is expressed by converting each byte into a, decimal number (0 to 255) and separating the bytes with, a period. For example, a server IP is like 130.132.59.234, Subnets: Although the individual subscribers do not, need to tabulate network numbers or provide explicit, routing, it is convenient for most Class B networks to be, internally manage as much smaller and simpler version, , Copyright @ NIMI Not to be Republished
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of the larger network organisations. It is common to, subdivide the two bytes available for internal assignment, into a one byte department number and a one byte, workstation ID. (Refer Fig 2), , There are three levels of TCP/IP knowledge. Those who, administer a regional or national network must design a, system of long distance phone lines, dedicated routing, devices and very large configuration files. They must, know the IP numbers and physical locations of thousands, of subscriber networks. They must also have a formal, network monitor strategy to detect problems and respond, quickly., Each large company or university that subscribes to the, Internet must have an intermediate level of network, organisation and expertise. A half dozen routers might be, configured to connect several dozen departmental LANs, in several buildings. All traffic outside the organisation, would typically be routed to a single connection to a, regional network provider., However, the end user can install TCP/IP on a personal, computer without any knowledge of either the corporate, or regional network. Three pieces of information are, required:, , The enterprise network is built using commercially, available TCP/IP router boxes. Each router has small, tables with 255 entries to translate the one byte department, number into selection of a destination Ethernet connected, to one of the routers., TCP treats the data as a stream of bytes. It logically, assigns a sequence number to each byte. The TCP, packet has a header that says, in effect, “This packet, starts with byte 379642 and contains 200 bytes of data.”, The receiver can detect missing or incorrectly sequenced, packets. TCP acknowledges data that has been received, and retransmits data that has been lost. The TCP design, means that error recovery is done end-to-end between, the Client and Server machine. There is no formal, standard for tracking problems in the middle of the, network, though each network has adopted some adhoc, tools., , 1 The IP address assigned to this personal computer., 2 The part of the IP address (the subnet mask) that, distinguishes other machines on the same LAN, (messages can be sent to them directly) from machines, in other departments or elsewhere in the world (which, are sent to a router machine), 3 The IP address of the router machine that connects, this LAN to the rest of the world., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.70, , Copyright @ NIMI Not to be Republished, , 189
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IT & ITES, Related Theory for Exercise 1.10.71 to 1.10.72, COPA - Networking Concepts, Transmission media and network components, Objectives :At the end of this lesson you shall be able to, • explain cable media, wireless media and network adapter., Network media : Media are what the message is, transmitted over. Different media have different properties, and are most effectively used in different environments, for different purposes., In computer networking, the medium affects nearly every, aspect of communication. Most important, it determines, how quickly and to whom a computer can talk and how, expensive the process is., , Cable media : Cables have a central conductor that, consists of a wire or fiber surrounded by a plastic jacket., Three types of cable media are twisted-pair, coaxial and, fiber-optic cable. Two types of twisted-pair cable are, used in networks: unshielded (UTP) and shielded (STP)., Table summarizes the characteristics of these types of, cable media, which are discussed in the following sections., , Factor, , UTP, , STP, , Coaxial, , Fiber-optic, , Cost, , Lowest, , Moderate, , Moderate, , Highest, , Installation, , Easy, , Fairly easy, , Fairly easy, , Difficult, , Bandwidth, capacity, , 1- to 155 Mbps, (typically 10 Mbps), , 1- to 155Mbps, (typically 16 Mbps), , Typically, 10 Mbps, , 2 Gbps, (typically 100 Mbps), , Node capacity, per segment, , 2, , 2, , 30 (10base 2), 100 (10 base 5), , 2, , Attenuation, , High (range of, hundreds of meters), , High (range of, hundreds of, meters), , Lower (range of a few, kilometers), , Lowest (range of, tens of kilometers), , EMI, , Most vulnerable to, EMI and, eavesdropping, , Less vulnerable, than UTP but still, vulnerable to EMI, and eavesdropping, , Less vulnerable than, UTP but still vulnerable, to EMI and, eavesdropping, , Not affected by, EMI or, eavesdropping, , Twisted-pair cable : Twisted-pair cable uses one or more, pairs of two twisted copper wires to transmit signals. It is, commonly used as telecommunications cable., When copper wires that are close together conduct, electric signals, there is a tendency for each wire to, produce interference in the other. One wire interferring, with another in this way is called crosstalk. To decrease, the amount of crosstalk and outside interference, the, wires are twisted. Twisting the wires allows the emitted, signals from one wire to cancel out the emitted signals, from the other and protects them from outside noise., Twisted pairs are two color-coded, insulated copper, wires that are twisted around each other. A twisted-pair, cable consists of one or more twisted pairs in a common, jacket. Fig 1 shows a twisted-pair cable., The two types of twisted-pair cable are unshielded and, shielded., 190, , Unshielded twisted-pair cable : Unshielded twistedpair (UTP) cable consists of a number of twisted pairs, with a simple plastic casing. UTP is commonly used in, telephone systems. Fig 2 shows a UTP cable., The Electrical Industries Association (EIA) divides UTP, into different categories by quality grade. The rating for, each category refers to conductor size, electrical characteristics and twists per foot. The following categories are, defined., , Copyright @ NIMI Not to be Republished
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The other side of the punch-down block is wired to a patch, panel. The patch panel provides connectivity through, patch cables to other user devices and connectivity, devices., UTP’s popularity is partly due to the, first usage of the, same in telephone systems. In many cases a network can, be run over the already existing wires installed for the, phone system, at a great savings in installation cost., , – Categories 1 and 2 were originally meant for voice, communication and can support only low data rates,, less than 4 megabits per second (Mbps). These, cannot be used for high-speed data communications., Older telephone networks used Category 1 cable., , Shielded twisted-pair cable : The only difference between shielded twisted pair (STP) and UTP is that STP, cable has a shielded usually aluminium/polyester between, the outer jacket or casing and the wires. Fig 4 shows STP, cable., , – Category 3 is suitable for most computer networks., Some innovations can allow data rates much higher,, but generally Category 3 offers data rates up to 16, Mbps. This category of cable is the kind currently used, in most telephone installations., – Category 4 offers data rates upto 20 Mbps., – Category 5 offers enhancements over Category 3,, such as support for Fast Ethernet, more insulation, and more twists per foot, but Category 5 requires, compatible equipment and more stringent installation., In a Category 5 installation, all media, connectors and, connecting equipment must support Category 5 or, performance will be affected., Data-grade UTP cable (Categories 3,4 and 5) consists of, either four or eight wires. A UTP cable with four wires is, called a two-pair. Network topologies that use UTP, require atleast two-pair wire. You may want to include an, extra pair for future expansion. Fig 3 shows a four-pair, cable., , Because UTP cable was originally used in telephone, systems, UTP installations are often similar to telephone, installations. For a four-pair cable, you need a modular, RJ-45 telephone connector. For a two-pair cable, you, need a modular RJ-11 telephone connector. These, connectors are attached to both ends of a patch cable., One end of the patch cable is then inserted into a, computer or other device, and the other end is inserted, into a wall jack. The wall jack connects the UTP drop, cable (another length of cable) to a punch-down block., , The shield makes STP less vulnerable to EMI because, the shield is electrically grounded. If a shield is grounded, correctly, it tends to prevent signals from getting into or, out of the cable. It is a more reliable cable for LAN, environments. STP was the first twisted-pair cable to be, used in LANs. Although many LANs now use UTP, STP, is still used., Transmission media specifications from IBM and Apple, Computer use STP cable. IBM’s Token Ring network, uses STP and IBM has its own specifications for different, qualities and configurations of STP. A completely different, type of STP is the standard for Apple’s Apple Talk, networks. Networks that confirm to each vendor’s specifications have their own special requirements, including, connector types and limits on cable length., STP has the following characteristics, Cost : Bulk STP is fairly expensive. STP costs more than, UTP and thin coaxial cable but less than thick coaxial or, fiber-optic cabling., Installation : The requirement for special connectors, can make STP more difficult to install than UTP. An, electrical ground must be created with the connectors. To, simplify installation, use standardised and prewired cables., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 191
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Because STP is rigid and thick (up to 1.5 inches in, diameter), it can be difficult to handle., , The following are some coaxial cables commonly used in, networking:, , Bandwidth capacity : With the outside interference, reduced by the shielding, STP can theoretically run at, 500 Mbps for a 100 meter cable length. Few installations, run at data rates higher than 155 Mbps. Currently, most, STP installations have data rates of 16 Mbps., , 50 ohm, RG-8 and RG-11 used for thick ethernet., , Node capacity : Since only two computers can be, connected together by an STP cable, the number of, computers in an STP network is not limited by the cable., Rather, it is limited by the hub or hubs that connect the, cables together. In a Token Ring network, which is the, most common type of STP network, the useful upper limit, is around 200 nodes in a single ring, but it depends on the, type of data traffic in your network. There is a specified, maximum limit of 270, but you will probably never reach, this limit., , PVC and plenum cable : Polyvinyl chloride (PVC) is, commonly used in coaxial cabling because it is a flexible,, inexpensive plastic well suited for use as insulation and, cable jacketing. PVC is often used in the exposed areas, of an office., , Attenuation : STP does not outperform UTP by much in, terms of attenuation. The most common limit is 100, meters., EMI : The biggest different between STP and UTP is the, reduction of EMI. The shielding blocks a considerable, amount of the interference. However, since it is copper, wire, STP still suffers from EMI and is vulnerable to, eavesdropping., Coaxial cable : Coaxial cable commonly called coax, has two conductors that share the same axis. A solid, copper wire or stranded wire runs down the center of the, cable and this wire is surrounded by plastic foam insulation., The form is surrounded by a second conductor, a wire, mesh tube, metallic foil or both. The wire mesh protects, the wire from EMI. It is often called the shield. A tough, plastic jacket forms the cover of the cable, providing, protection and insulation. Fig 5 shows a coaxial cable., , 50 ohm, RG-58 used for thin ethernet., 75 ohm, RG-59 used for cable TV., 93 ohm, RG-62 used for ARCnet., , A plenum is the space between the false ceiling of an, office and the floor above. The air in the plenum circulates, with the air in the rest of the building, and there are strict, fire codes about what can be placed in a plenum, environment., Because PVC gives off poisonous gases when burned,, you cannot use it in a plenum environment. You must use, plenum grade cable instead. Plenum grade cable is, certified to be fire resistant to produce a minimum, amount of smoke. Plenum cable is also used in vertical, runs (walls) without conduit (a tube to hold the cable)., Plenum cable is more expensive and less flexible than, PVC., Fiber-optic cable : Fiber-optic cable transmits light, signals rather than electrical signals. It is enormously, more efficient than the other network transmission media., As soon as it comes down in price (both in terms of the, cable and installation costs) fibre optic will be the choice, for network cabling., Each fiber has an inner core of glass or plastic that, conducts light. The inner core is surrounded by cladding,, a layer of glass that reflects the light back into the core., Each fiber is surrounded by a plastic sheath. The sheath, can be either tight or loose. Fig 6 shows examples of, these two types of fiber optic cables., , Coaxial cable comes in different sizes. It is classified by, size (RG) and by the cable’s resistance to direct or, alternating electric currents (measured in ohms also, called impedance), 192, , Tight configurations completely surround the fibers with, a plastic sheath and sometimes include wires to strengthen, the cable (although these wires are not required). Loose, configurations leave a space between the sheath and the, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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outer jacket, which is filled with a gel or other material., The sheath provides the strength necessary to protect, against breaking or extreme heat or cold. The gel,, strength wires and outer jacket provide extra protection., A cable may contain a single fiber, but often fibers are, bundled together in the center of the cable. Optical fibers, are smaller and lighter than copper wire. One optical fiber, is approximately the same diameter as a human hair., Optical fibers may be multimode or single mode. Single, mode fibers allow a single light path and are typically, used with laser signaling. Single mode fiber can allow, greater bandwidth and cable runs than multimode but is, more expensive. Multimode fibers use multiple light, paths. The physical characteristics of the multimode, fiber make all parts of the signal (those from the various, paths) arrive at the same time, appearing to the receiver, as though they were one pulse. If you want to save, money, look into multimode, since it can be used with, LEDs (light emitting diodes) which are a more affordable, light source than lasers. Fig 7 shows single mode and, multi mode fibers., , bounded media difficult. There are three main types of, wireless media: radio wave, micro wave and infrared., Radio wave transmission systems : Radio waves, have frequencies between 10 kilohertz (KHz) and 1, gigahertz (GHz). The range of the electromagnetic, spectrum between 10 KHz and 1 GHz is called radio, frequency (RF)., Radio wave include the following types., Short wave, Very high frequency (VHF) television and FM radio, Ultra-high frequency (UHF) radio and television, Radio waves can be broadcast omnidirectionally or, directionally. Various kinds of antennas can be used to, broadcast radio signals., Microwave transmission systems : Microwave communication makes use of the lower gigahertz frequencies, of the electromagnetic spectrum. These frequencies,, which are higher than radio frequencies, produce better, throughout and performance. There are two types of, microwave data communication systems: terrestrial and, satellite., Terrestrial microwave : Terrestrial microwave systems, typically use directional parabolic antennas to send and, receive signals in the lower gigahertz range. The signals, are highly focused and the physical path must be line-ofsight. Relay towers are used to extend signals. Terrestrial, microwave systems are typically used when using cabling, is cost prohibitive., Because terrestrial microwave equipment often uses, licensed frequencies, additional costs and time constraints, may be imposed by licensing commissions or government, agencies (the FCC, in the United States)., , Optical fibers are differentiated by core/cladding size, and mode. The size and purity of the core determine the, amount of light that can be transmitted. The following are, the common types of fiber-optic cable., 8.3 micron core/125 micron cladding, single mode, 62.5 micron core/125 micron cladding, multimode, 50 micron core/125 micron cladding, multimode, 100 micron core/140 micron cladding, multimode, A typical LAN installation starts at a computer or network, device that has a fiber-optic network interface and (NIC)., This NIC has an incoming interface and an outgoing, interface. The interfaces are directly connected to fiberoptic cables with special fibre-optic connectors. The, opposite ends of the cables are attached to a connectivity, device or splice center., Wireless media : Wireless media do not use an electrical, or optical conductor. In most cases, the earth’s atmosphere is the physical path for the data. Wireless media is, therefore useful when distance or obstructions make, , Fig 8 shows a microwave system connecting separate, buildings. Smaller terrestrial microwave systems can be, used within a building, as well. Microwave LANs operate, at low power, using small transmitters that communicate, with omnidirectional hubs. Hubs can then be connected, to form an entire network., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 193
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Satellite : Satellite microwave systems transmit signals, between directional parabolic antennas. Like terrestrial, microwave systems, they use low gigahertz frequencies, and must be in line-of-sight. The main difference with, satellite system is that one antenna is on a satellite in, geosynchronous orbit about 50,000 kilometers (22,300, miles) above the earth. Because of this, satellite microwave systems can reach the most remote places on earth, and communicate with mobile devices., Here’s how it usually works: a LAN sends a signal, through cable media to an antenna (commonly known as, a satellite dish), which beams the signal to the satellite in, orbit above the earth. The orbiting antenna then transmits, the signal to the another location on the earth or, if the, destination is on the opposite side of the earth, to another, satellite, which then transmits to a location on earth., Fig 9 shows a transmission being learned from a satellite, dish on earth to an orbiting satellite and then back to, earth., , Because the signal must be transmitted 50,000 kilometers, to the satellite and 50,000 kilometers back to earth,, satellite microwave transmissions take about as long to, cover a few kilometers as they do to span continents., Because the transmission must travel long distances,, satellite microwave systems experience delays between, the transmission of a signal and its reception. These, delays are called propagation delays. Propagation delays, range from .5 to 5 seconds., Infrared transmission systems : Infrared media use, infrared light to transmit signals. LEDs or ILDs transmit, the signals and photodiodes receive the signals. Infrared, media use the tera-hertz range of the electromagnetic, spectrum. The remote controls we use for television,, VCR and CD players use infrared technology to send and, receive signals., , Infrared media use pure light, normally containing only, electromagnetic waves or photons from a small range of, the electromagnetic spectrum. Infrared light is transmitted, either line-of-sight (point-to-point) or broadcast, omnidirectionally, allowing it to reflect off walls and, ceilings. Point-to-point transmission allows for better, data rates, but devices must remain in their locations., Broadcast, on the other hand, allows for more flexibility, but with lower data rates. (Part of the signal strength is, lost with each reflection.), Point-to-point : Infrared beams can be tightly focused, and directed at a specific target. Laser transmitters can, transmit line-of-sight across several thousand meters., One advantage of infrared is that an FCC license is not, required to use it. Also, using point-to-point infrared, media reduces attenuation and makes eavesdropping, difficult. Typical point-to-point infrared computer, equipment is similar to that used for consumer product, with remote controls. Careful alignment of transmitter, and receiver is required. Fig 10 shows how a network, might use point-to-point infrared transmission., , Broadcast : Broadcast infrared systems spread the, signal to cover a wider area and allow reception of the, signal by several receivers. One of the major advantage, is mobility; the workstations or other devices can be, moved more easily than with point-to-point infrared, media. Fig 11 shows how a broadcast infrared system, might be used., Because broadcast infrared signals are not as focussed, as point-to-point, this type of system cannot offer the, same throughout. Broadcast infrared is typically limited, to less than 1 Mbps, making it too slow for most network, needs., Network adapters, sometimes called Network Interface, Cards (NICs) are peripheral cards that plug into the, motherboard of your computer and into a network cable., It is through the network adapter that your computer, communicates on the network. Many newer IBMcompatible computers have built-in networking adapters, for Ethernet., , Because infrared signals are in the terahertz (higherfrequency) range, they have good throughout. Infrared, signals do have a downside: the signals cannot penetrate, Network adapters perform all the functions required to, walls or other objects and they are diluted by strong light, communicate on a network. They convert data from the, sources., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, 194, , Copyright @ NIMI Not to be Republished
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form stored in the computer to the form transmitted or, received (or transceived) on the cable and provide a, physical connection to the network., , How network adapters work : Network adapters receive, the data to be transmitted from the motherboard of your, computer into a small amount of RAM called a buffer., The data in the buffer is moved into a chip that calculates, a checksum value for the chunk and adds address, information, which includes the address of the destination, card and its own address, which indicates where the data, is from. Ethernet adapter addresses are permanently, assigned when the adapter is made at the factory. This, chunk is now referred to as a frame., For example, in Ethernet, the adapter listens for silence, on the network when no other adapters are transmitting., It then begins transmitting the frame one bit at a time,, starting with the address information, then the chunk of, data and then the checksum., , Fig 12 shows how an adapter plugs into a computer and, attaches to a network cable., , The network adapter must still convert the serial bits of, data to the appropriate media in use on the network. For, instance, if the data is being transmitted over optical, fiber, the bits are used to light up an infrared LED (light, emitting diode) or laser diode, which transmits light, pulses down the fiber to the receiving device’s APD, (avalanche photo diode) or photo-transistor. If the data is, being sent over twisted-pair cable, the adapter must, convert the bits of data from the 5-volt logic used in, computers to the differential logic used for digital twistedpair transmission., The circuitry used to perform this media conversion is, called a transceiver. Ethernet is the same no matter what, type of media you use only the transceiver changes., Transceivers can be external devices attached through, the AUI port on an Ethernet adapter, or they can be, internal on the card. Some cards (usually called combo, cards) have more than one type of transceiver built in so, you can use them with your choice of media. AUI, interfaces on Ethernet adapters are not transceiversthey are where you attach a transceiver for the different, media types., , Adapters in Abstract : Your computer software does not, have to be aware of how the network adapter performs its, function because the network driver software handles all, the specifics for your computer. The applications running, on your computer need only address data and hand it to, the adapter card., This is much the way the post office or a parcel delivery, service works. You don’t care about the details of postal, delivery; you simply address your parcel and hand it to, the delivery driver. The postal service manages the, process of delivering it for you., This abstraction allows your computer to use a microwave, radio transmitter just as earily as a fiber-optic network, adapter or an adapter that works over coaxial cable., , Because a network signal travels through copper and, optical fiber at about 66 percent as fast as the speed of, light, there’s a chance that one of two adapters far away, from each other could still be hearing silence when the, other has in fact started transmitting. In this case, they, could transmit simultaneously and garble their data. This, is referred to as a collision., While adapters transmit, they listen to the wire to make, sure the data on the line matches the data being transmitted. As long as it does, everything is fine. If another, adapter has interrupted, the data being, “heard” by the, transmitting network adapter will not match the data, being transmitted. If this happens, the adapter ceases, transmitting and transmits a solid on state instead, which, indicates to all computers that it has detected a collision, and that they should discard the current frame because, it has been corrupted. The network adapter waits a, random amount of time and then again attempts to, transmit the frame., , Everything in your computer remains the same except for, the actual network adapter and the driver software for that, adapter., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 195
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Configuring network adapters : Because network adapters have not been around since computers were invented,, there is no assigned place for cards to be set to. Most, adapter cards require their own interrupt, port address and, upper memory range. PCI motherboards automatically, assign IRQ and post settings to your PCI card, so you don’t, need to worry about it., Unfortunately, network adapters in computers with ISA, buses can conflict with other devices, since no two devices, , 196, , should share the same interrupt or port. No software that, comes with your computer will tell you every interrupt and, port in use unless your computer is already running, Windows NT, so you must be somewhat familiar with the, hardware in your computer or use a program that can probe, for free resources to find one. Many adapters have test, programs that can tell you whether the adapter is working, correctly with the settings you’ve assigned., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73A, , Computer name and workgroup - Client server, Objectives : At the end of this lesson you shall be able to, • define computer name, • define workgroup, • explain client-server model, centralised computing and client computing with central file storage, • explain web server., Computer Name: In network computers are identified by, its IP Address, but a name can also be given to identify it, easily as remembering IP address is difficult comparing, remembering a alphanumeric name., Client-Server : The term Client-Server can describe, hardware, in which case it is referring to network servers, and client computers, or it can refer to a way of organising, software applications and services on a network. Clientserver computing is a powerful way of constructing, programs on a network. In order to describe its advantage, and how it works, we will first describe two alternatives to, client-server computing:, – Centralised computing, – Client computing with central file storage, Centralized computing : Centralized computing originated with mainframe computers and time-sharing. The, principle behind centralized computing is that a central, computer executes a program, such as a database or a, transaction-processing program (for instance, an airline, reservations system or a bank records program) and, remote terminals merely display data on a screen and, convey keyboard data back to the central computer., , Workgroup: In a network computers can be grouped, together by using workgroup feature. Computers in a, particular workgroup will show together when you open a, workgroup. Though a computer of one workgroup can, access other workgroup computers also., Client computers cooperate to ensure that central files, are not corrupted by attempts by several computers to, access them at the same time. When a client computer, needs to perform an operation, the file is transferred to, the client computer to perform the operation. Two, examples of this type of application are networked, database programs that do not use a SQL. (Structured, Query Language) server and any network-aware, application that does not communicate with a special, program executing on the server, such as network, scheduling programs and groupware., , In modern networks, personal computers can perform, the role of dumb terminals. With Windows software, the, PC can appear to the central computer as many terminals,, each virtual terminal accessing different data or, performing a separate transaction on the mainframe., In centralized computing it is the central computer that, does all the work. The data resides on the central, computer and the program executes on the central, computer. The personal computer or dumb terminal only, display screen data and accepts keystrokes for the, central computer to process. Centralized computing, does not fully use the capabilities of today’s powerful, network clients. Fig 1 illustrates centralized computing., Client computing with Central file storage : At the, opposite end of the spectrum from centralized computing, is client computing with central file storage (see Fig 2). In, this way of organizing an application, the client computer, does all the work. A central file server stores, but that is, all., , Copyright @ NIMI Not to be Republished, , 197
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One example of a front end is Microsoft Access when it, is used with a SQL back end. (You can also use Access, without a SQL back end.) Access displays tables in, windows or in forms you can browse. It allows you to, modify and search the tables in an easy-to-use graphical, environment. All the actual data manipulation, however,, occurs on the SQL server. Access translates all the database operations into SQL for the server to perform. The, results of the operations are transmitted back to Access, to display in an intuitive, graphical form., , While it is fully exploits the capabilities of client computers, and provides a richer and more customizable environment, for the user, this type of program can place heavy, demands on the network if the data files in which program, works with are large. It also takes time to transmit data, from the server to the client, process the data, and, transfer it back to the server so other network programs, can access the data., The Client-Server Model : The client-server model, combines the advantages of both the centralized, computing model and the client model of computing. It, does this by performing the operations that are best, executed by a central computer on the file server and, performing those operations that are best done close to, the user on the client computer (see Fig 3). The clientserver model works best when many people need access, to large amounts of data. Simply stated, a client-server, system is any system in which the client computer makes, a request over a network to a server computer that then, satisfies the request., The Client : When you use a client-server system, what, you see is the client, or front end. It presents the interface, to manipulate or search for data. The request you make, by manipulating windows, menu, check boxes and so on,, is translated into a compact form that the client transmits, over the network for the server to perform., , SQL is not limited to database programs such as Microsoft, Access. User programs such as Microsoft Excel can use, SQL to query the back-end data-base server for values, to use in spreadsheet calculations. Program tools allow, custom programs to store and retrieve data in serverbased databases. Query tools provide direct access to, the SQL data., The Server : The server is where data operations in a, client-server system occur. The central computer can, service many client requests quickly and efficiently,, which is the traditional advantage of centralized, computing. The central computer can also provide, enhanced security by performing only authorized, operations on the data., Back-end database software is optimized to perform, searches and sorts and the back-end computer is often, more powerful than the front-end computer., Web server : A web server is a program using the client/, server model and the World Wide Web’s Hyper Text, Transfer Protocol (HTTP) serves the files that form web, pages to web users., Every computer on the internet that contains a web site, must have a web server program. The most popular web, servers are: The Microsoft’s Internet Information Server, (IIS) which comes with the Microsoft’s Windows NT, Server; Netscape Fast Track and Enterprises Servers, and Apache, a web server for Unix-based operating, systems. Other web servers include Novell’s Web Server, for users of its Netware Operating System and IBM’s, family of Lotus Domino Servers. Primarily for IBM’s OS/, 390 and AS/400 customers., Web servers often come as a part of a larger package of, Internet related programs for serving e-mail, downloading, requests for File Transfer Protocol (FTP) files and building, and publishing web pages. Consideration in choosing a, web server include how well it works with the operating, system and other servers, its ability to handle server side, programming and publishing, search engine and site, building tools that may come with it., , 198, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished
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DHCP, Objectives : At the end of this lesson you shall be able to, • define DHCP, • explain DHCP., DHCP: Dynamic Host Control Protocol allows server, computers to distribute dynamic IP address when the, client establish connection to server. The server, maintains a IP address pool and it offer some IP which, is not already alloted to some other client. When client, disconnects from server its IP then becomes free again, and can be given to other client., , superseded by RFC 2131) that allows a server to, dynamically distribute IP addressing and configuration, information to clients. Normally the DHCP server, provides the client with at least this basic information:, , It is dynamic as same client can get different IP in, different times. It is beneficial as requirement of IP, address is less a all the clients are not always connected, to server and its saves the time to allocate IP to each, client manually., Dynamic Host Configuration Protocol (DHCP) is a, standard protocol defined by RFC 1541 (which is, , •, , IP Address, , •, , Subnet Mask, , •, , Default Gateway, , Other information can be provided as well, such as, Domain Name Service (DNS) server addresses and, Windows Internet Name Service (WINS) server, addresses. The system administrator configures the, DHCP server with the options that are parsed out to the, client., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished, , 199
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73B, , Concept of proxy server, Objectives : At the end of this lesson you shall be able to, • explain the meaning of proxy server, • explain common connection point, • explain packet filtering, domain filtering and control user access by service, • explain logging and web publising., What is a proxy server? To be a “proxy” means to act on, behalf of another. This is exactly what a proxy server does;, it acts on behalf of its proxy clients to interact with other, servers. You could say that a proxy server is a “mediator”, for computer communications., Placing a proxy server on your network gives you several, advantages, including security enhancements, coaching, enhancements and greater control over your network, users. The advantages of using Microsoft Proxy Server, (MPS) is listed below:, – Common connection point, – Caching, – Packet filtering, – Domain filtering, – Control user access by service, – Logging, – Web publishing, Common connection point : MPS was designed to, connect two networks, rather like a gateway. Typically,, MPS connects an internal network and the Internet. This, configuration gives the internal computers a common, connection point to the Internet-through MPS., When used to provide a common connection, MPS lets, clients share a single connection to the Internet. Instead of, giving each user on a Local Area Network (LAN) a separate, modem, phone line and dial-up account to the Internet,, MPS can function as a gateway to the Internet using a, single connection. Instead of using separate standard, phone line connections, users can share a single higherspeed connection through the proxy server. The net effect, is usually an overall cost savings and reduction in administrative overhead. One connection is usually cheaper and, easier to maintain than several separate connections., Caching : Since you can use MPS as a common connection point to the Internet, you can also use it to cache, frequently accessed resources. MPS allocates a portion of, the server’s hard disk space to store frequently accessed, objects., Caching can either be passive or active. Passive caching, just stores objects as they are requested so the cache is, updated only when users request information. Active, caching directs the server to refresh objects in the cache, automatically., 200, , You can selectively control MPS caching so that you can, limit the size of cached objects, change the expiration, limits (control the freshness of objects) and determine, whether MPS always caches or always excludes from, cache certain content., Caching only works with the Web Proxy Service, in MPS. You will learn more about the Web Proxy, Service later in this chapter., Packet Filtering : To protect internal users from the, outside world (in other words to protect the network from, outsiders), MPS provides packet-filtering services. A packet, filter prevents unauthorized access from the outside by, limiting the available connection points coming into the, network. To that end, packet filters stop various types of, protocols from entering the network., MPS supports both static and dynamix packet filters. A, static filter keeps all traffic of a certain description or type, from passing through MPServer. A dynamic packet filter, automatically determines which type of traffic is allowed in, or out. With a static filter the administrator defines the port,, the protocol and may be the IP address. With a dynamic, filter the administrator just defines the service to be allowed, or filtered., Domain Filtering : MPS also lets you limit the access of, your internal clients to the Internet. You can configure, filters for a single computer, a group of computers or a, domain name. Many companies prefer to have this type of, control over their users because they can block access to, Internet sites that they believe reduce employee productivity or contain offensive material. Some popular examples, of domain filtering are blocking access to Internet game, servers or Web sites that contain pornographic material., You can configure domain filters for a specific IP address,, IP address and subnet mask or domain name. IP address, filters prevent users from contacting a single computer., Using the IP address and subnet mask as a filter limits, access to an entire group (a subnet) of computers. Domain, name filters can apply to an entire Web site or to subsections of that site., Control user access by Protocol or Service : You can, also selectively enable and disable ports, services and, protocols through MPS. MPS lets you control access to, Internet services at the user level. You can also enable or, restrict access to protocols on a user or group basis. Many, protocols are predefined in the default MPS configuration., , Copyright @ NIMI Not to be Republished
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If the protocol or service you would like to enable or disable, is not defined in the MPS property sheets, you can create, a new sheet. you can define a protocol by TCP (Transmission Control Protocol) or UDP (User Datagram Protocol), port number or range. This gives you the ability to control, access by port., Logging : Because all traffic between networks passes, through MPS, MPS has the unique opportunity to log and, track communication. You can track the information your, internal clients get from other networks or the Internet and, monitor inbound communication. You can use this information to help you secure your internal network from attack, and unauthorized access. Plus, you can monitor where, your users spend their time on the Internet and what, information they are downloading., Web publishing : MPS can also act as a Web server., MPS can service requests from cache on behalf of a Web, server, pass requests to the Web server on the local, system or pass requests to another Web server on the, internal network. The terms “reverse proxying” and “reverse, hosting” describe the Web Publishing services that MPS, provides., As a reverse proxy, MPS listens to incoming Web requests, for a single Web server on the local network. The incoming, requests are simply forwarded to another Web server. Web, hosting requires more work on the part of MPS. As a, reverse host, MPS can send requests to one of many Web, servers. In this case, MPS responds as if the entire site, were contained locally, even though the actual data may be, coming from several different Web servers., The main difference between reverse proxying and reverse, hosting is that in performing reverse proxying, MPS forwards all requests to the Web server. In performing reverse, hosting, MPS selectively forwards requests to multiple, Web servers on the internal network. In reverse hosting, the, Microsoft Proxy Server routes an external request for a, resource (that specifies an Internet domain name) to one, or more internal Web servers. For instance, requests for, http://www.hudlogic.com/bios might be routed to an internal server named “business” (http://business), while requests for http://www.hudlogic.com/pictures could be sent, to a different Web server named “server1” (http://server1)., Services : Microsoft Proxy Server 2.0 supports Hypertext, Transfer Protocol (HTTP) version 1.1, Windows Sockets, version 1.1, SOCKS version 4.3a and Secure Sockets, Layer (SSL) 3.0. The MPS services that provide this, support are the Web Proxy service, WinSock Proxy, service and the SOCKS Proxy service, respectively., , Web Proxy Service : The Web Proxy service provides, support for HTTP (a.k.a.Web publishing), FTP, Gopher and, secure (SSL) communications. The Web Proxy service, works with any CERN-compliant Web browser, such as, Internet Explorer or Netscape Navigator. Because the Web, Proxy supports only these widely adopted Internet standard communication methods, it isn’t operating system, dependent. Clients running Unix, Macintosh or Windows, operating systems can communicate with the Web Proxy, service as long as they’re configured with a CERN-complaint Web browser., Any operating system using a CERN-compliant, Web browser can communicate through the Web, Proxy server, regardless of its underlying operating system., WinSock Proxy Service : The WinSock Proxy service, supports Microsoft Windows operating systems using, Windows Sockets. This supprt is available for both Transmission Control Protocol/internet Protocol (TCP/IP) and, Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocols. The WinSock Proxy service, applies mainly to Windows clients including Windows 3.x,, windows 95 and Windows NT., Windows Sockets is an interprocess communication, mechanism derived from the Berkeley Sockets interface, (originally designed for Unix systems). The Sockets interface was extended to support Windows-based clients, running Microsoft implementations of TCP/IP. The name, given to this Sockets interface for Windows was WinSock, (for Windows Sockets)., The WinSock Proxy Service doesn’t support 16-bt, IPX/SPX clients such as the Windows 3.x 16-bit, Netware clients., SOCKS Proxy Service : The SOCKS Proxy service, supports SOCKS version 4.3a client applications such as, FTP, Gopher and Telnet. Operating systems like Macintosh and Unix can run SOCKS 4.3a and access the, SOCKS Proxy service when communicating through the, Microsoft Proxy Server. One limitation of the SOCKS proxy, service on MPS is that it does not support UDP-based, protocols., UDP-based protocols aren’t supported through, the SOCKS Proxy service, but the WinSock Proxy, service does support UDP for Windows clients., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73B, , Copyright @ NIMI Not to be Republished, , 201
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.74, , Video conferencing, Objectives: At the end of this lesson you shall be able to, • define video conferencing, • list the advantages of video conferencing, • list the disadvantages of video conferencing., Video Conferencing, , and eye contact in these. Video conferencing allows, users to successfully convey, creating essential social bonds and shared understandings., , Definition: Videoconferencing is the conduct of a conference by a set of telecommunication technologies, which allow two or more remotely located teams to communicate by simultaneous two-way video and audio, transmissions. It has also been called 'visual collaboration' and is a type of groupware., , 5 Increased Productivity, , Video conferencing is a very useful technique to cut down, various costs as well as travel time when meetings and, conferences are concerned.Video conferencing connects, individuals in real time through audio and video communication over broadband networks. It enables visual, meetings and collaboration on digital documents and, shared presentations. New technologies allow participants to connect remotely over a network through multiple devices like laptops, desktops, smartphones and, tablets., , 7, , Advantages, 1 Significant Travel Savings, 2 Not only is video conferencing a direct replacement, for many in-person business trips, but because there, is virtually no cost to add additional key employees, to a virtual meeting, it is a cost effective solution., , 6 Important meetings are shorter and more effective., But it is a well-known fact that many meetings take, longer than the necessary time of the participants., Video conferencing users can save a minimum of, two hours a week with the technology. The interactivity, of group collaboration and document sharing greatly, increases productivity., Conferencing Quality, , 8 The present day state-of-the-art technology delivers, excellent, reliable audio and video quality, making, conferencing very effective and interesting too., Disadvantages, 1 Absence of Physical Presence, 2 Initial installation costs, 3 Not yet popular with a large size of users., , 3 Improved Communication, 4 Audio conferencing and e-mail may be used for communication but there is a lack of visual connection, , 202, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.75, , Network security, Objectives: At the end of this lesson you shall be able to, • define network security, • explain network security concepts., Network security consists of the provisions and policies, adopted by a network administrator to prevent and, monitor unauthorizedaccess, misuse, modification, or, denial of a computer network and network-accessible, resources. Network security involves the authorization, of access to data in a network, which is controlled by the, network administrator., Network security concepts, Network security refers to any activities designed to, protect your network. Specifically, these activities protect, the usability, reliability, integrity, and safety of your, network and data. Effective network security targets a, variety of threats and stops them from entering or, spreading on your network., Network security starts with authenticating, commonly, with a username and a password. Since this requires, just one detail authenticating the user name -i.e. the, password- this is sometimes termed one-factor, authentication. With two-factor authentication, something, the user needs a 'dongle', an ATM card, or a mobile, phone, and with three-factor authentication, something, the user needs a fingerprint or retinal scan., Once authenticated, a firewall decides what services, are allowed to be accessed by the network users. Though, effective to prevent unauthorized access, this component, may fail to check potentially harmful content such as, computer worms or Trojans being transmitted over the, network., Anti-virus software or an intrusion prevention system, (IPS) helps detect and inhibit the action of such malware., Encrypting the communication between two hosts using, a network helps maintain privacy., Surveillance and early-warning toolssometimes referred, to as Honeypots can be employed., Hhoneypot is a trap set to detect, deflect, or, in some, manner, counteract attempts at unauthorized use of, information systems. Generally, a honeypot consists of, a computer, data, or a network site that appears to be, part of a network, but is actually isolated and monitored,, and which seems to contain information or a resource of, value to attackers. This is similar to the police baiting a, criminal and then conducting undercover surveillance., , The Foundations of Security, Security relies on the following elements:, •, , Authentication, , Authentication addresses the question: who are you? It is, the process of uniquely identifying the clients of your, applications and services. These might be end users,, other services, processes, or computers. In security, parlance, authenticated clients are referred to as, principals., •, , Authorization, , Authorization addresses the question: what can you do?, It is the process that governs the resources and, operations that the authenticated client is permitted to, access. Resources include files, databases, tables, rows,, and so on, together with system-level resources such as, registry keys and configuration data. Operations include, performing transactions such as purchasing a product,, transferring money from one account to another, or, increasing a customer's credit rating., •, , Auditing, , Effective auditing and logging is the key to nonrepudiation. Non-repudiation guarantees that a user, cannot deny performing an operation or initiating a, transaction. For example, in an e-commerce system,, non-repudiation mechanisms are required to make sure, that a consumer cannot deny ordering 100 copies of a, particular book., •, , Confidentiality, , Confidentiality, also referred to as privacy, is the process, of making sure that data remains private and confidential,, and that it cannot be viewed by unauthorized users or, eavesdroppers who monitor the flow of traffic across a, network. Encryption is frequently used to enforce, confidentiality. Access control lists (ACLs) are another, means of enforcing confidentiality., •, , Integrity, , Integrity is the guarantee that data is protected from, accidental or deliberate (malicious) modification. Like, privacy, integrity is a key concern, particularly for data, passed across networks. Integrity for data in transit is, typically provided by using hashing techniques and, message authentication codes., , Copyright @ NIMI Not to be Republished, , 203
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•, , Availability, , How Do You Build a Secure Web Application?, , From a security perspective, availability means that, systems remain available for legitimate users. The goal, for many attackers with denial of service attacks is to, crash an application or to make sure that it is sufficiently, overwhelmed so that other users cannot access the, application.Threats, Vulnerabilities, and Attacks Defined, A threat is any potential occurrence, malicious or, otherwise, that could harm an asset. In other words, a, threat is any bad thing that can happen to your assets., A vulnerability is a weakness that makes a threat, possible. This may be because of poor design,, configuration mistakes, or inappropriate and insecure, coding techniques. Weak input validation is an example, of an application layer vulnerability, which can result in, input attacks., , It is not possible to design and build a secure Web, application until you know your threats. An increasingly, important knowledge needed is about threat modeling., The purpose of threat modeling is to analyze your, application's architecture and design and identify, potentially vulnerable areas that may allow a user,, perhaps mistakenly, or an attacker with malicious intent,, to compromise your system's security., After you know your threats, design with security in mind, by applying proven security principles. You must follow, secure coding techniques to develop secure, robust, and, hack-resilient solutions. The design and development of, application layer software must be supported by a secure, network, host, and application configuration on the, servers where the application software is to be deployed., , An attack is an action that exploits a vulnerability or, enacts a threat. Examples of attacks include sending, malicious input to an application or flooding a network in, an attempt to deny service., , 204, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.75, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.76 & 1.11.77, , E-mail, Objectives : At the end of this lesson you shall be able to, • state the hotmail services offered, • explain MSN outlook express and its tools, • explain popular search engines, • state the FAQs about hotmail., Hotmail: MSN Hotmail is the world’s largest provider of, free Web-based e-mail. Hotmail is based on the premise, that e-mail access should be easy and possible from any, computer connected to the World Wide Web., By adhering to the universal HyperText Transfer Protocol, (HTTP) standard, Hotmail eliminates the disparities that, exist between different e-mail programs. Sending and, receiving e-mail from Hotmail is as easy as going to the, Hotmail web site at http://www.hotmail.com, or by clicking, on the Hotmail link at http://www.msn.com, signing in,, and sending an e-mail message., Hotmail is the web-based e-mail provider, which means, you can send and receive messages from any computer, connected to the Internet. You can use Hotmail from, home, work, school, an Internet cafe, a friend’s house or, any other computer in the world with an Internet connection. Your messages are stored in a central location, so, your Inbox will always be up to date. This is great for, people who use more than one computer, travel frequently, or don’t even own a computer., Advantages of Hotmail, Get a permanent e-mail address: When you create a, Hotmail account, you choose a permanent e-mail address that will never change as long as you continue to, use Hotmail. This is great for people who: Want to switch, Internet Service Providers. Your Hotmail address will be, the same no matter how you access the Internet, so you, don’t have to worry about retrieving messages from your, old address or notifying friends, family and associates of, a new e-mail address. You are free to select any Internet, Service Provider that suits your needs., When you leave town for travel, you may no longer have, access to your ISP’s e-mail account. But with Hotmail,, your friends will always know where to reach you., Your e-mail is private and secure: When you sign up, for Hotmail, you choose your personal ID and password., The only way you can access your account is by using the, password you selected. This means that only you will, have access to your Hotmail account, even if you use a, computer at a public terminal or a friend’s house. Because, the messages in your Hotmail account are stored securely at a central location, you don’t have to worry about, losing important information if something happens to, your computer. Hotmail is strongly committed to keeping, your personal information confidential., , Hotmail is fast and easy to use: Hotmail is recognized, world wide as the best Web-based e-mail service. It is, also stated that ‘while others provide similar services,, none can match Hotmail’s general ease of use’. If everything is fine, it takes less than a minute to get started on, Hotmail and its pages are so worked out to load quickly, knowing that the users time is valuable., Get an additional e-mail account for FREE:Hotmail, offers everyone the opportunity to get a free e-mail, account. Hotmail can offer e-mail accounts for free, because it places banner advertising on some of its, pages. Some Internet Service Providers charge a monthly, fee for additional e-mail accounts. Hotmail lets an, unlimited number of people use a single Internet Service, Provider account and have a free, personal e-mail, account., Keep your personal e-mail separate from your work, e-mail: People who use e-mail for work will find it, convenient to keep their personal messages separate, from their work messages. You can use Hotmail for your, personal correspondence and your company’s e-mail, system only for business messages. Additionally, you, don’t have to store personal e-mail on your company’s, servers. All messages in your Hotmail account are, securely stored in a central location that you access via, the Internet with the password you select., Outlook Express, Microsoft Outlook Express puts the world of online, communication on your desktop. Whether you want to, exchange e-mail with colleagues and friends or join, newsgroups to trade ideas and information. Some of the, tools offered by outlook express are;, Manage multiple mail and news accounts: If you have, several mail or news accounts, you can use them all from, one window. You can also create multiple users, or, identities, for the same computer. Each identity gets its, own mail folders and Address Book. The ability to create, multiple accounts and identities makes it easy for you to, keep work separate from personal mail and also between, individual users., Browse through messages quickly & easily: Using, the message list and preview pane, you can view a list of, messages and read individual messages at the same, time. The Folders list contains mail folders, news servers,, and newsgroups, and you can easily switch between, them. You can also create new folders to organize and, sort messages, and then set up message rules so that, , Copyright @ NIMI Not to be Republished, , 205
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incoming mail that meets your criteria automatically, goes to a specific folder. You can also create your own, views to customize the way you look at your mail., Keep your mail on a server so you can view it from, more than one computer: If your ISP uses an IMAP, mail server for incoming mail, you can read, store, and, organize your messages in folders on the server without, downloading the messages to your computer. That way,, you can view messages from any computer that can, connect to that server., Use the Address Book to store and retrieve e-mail, addresses: You can save names and addresses in your, Address Book automatically by simply replying to a, message or by importing them from other programs, by, typing them in, by adding them from e-mail messages, you receive, or by searching popular Internet directory, services (white pages). The Address Book supports, Lightweight Directory Access Protocol (LDAP) for, accessing Internet directory services., Add a personal signature or stationery to your messages: You can insert essential information into outgoing messages as part of your personal signature, and you, can create multiple signatures to use for different, purposes. For more detailed information, you can include, a business card. To make your messages look more, attractive, you can add stationery patterns and backgrounds, and you can change the color and style of the, text., Send and receive secure messages: You can digitally, sign and encrypt messages by using digital IDs. Digitally, signing your message assures recipients that the message is really from you. Encryption ensures that only, intended recipients can read a message., Find newsgroups that interest you: Looking for a, newsgroup that matches your interests? You can search, for newsgroups that contain keywords or browse through, all of the newsgroups available from your Usenet provider. When you find a newsgroup you want to view, regularly, add it to your Subscribed list so you can find it, again easily., View newsgroup conversations efficiently: You can, view a newsgroup message and all of the responses, without reading an entire message list. When you view, the list of messages, you can expand and collapse, conversations to make it easier to find what interests you., You can also use views to display only the messages you, want to read., Download newsgroup messages for offline reading:, To use your online time efficiently, you can download, messages or entire newsgroups, so you don’t have to be, connected to your ISP to read messages. You can also, download message headers only for offline viewing and, then mark the headers of the messages you want to read;, then the next time you are connected, Outlook Express, downloads the message text. You can also compose, messages offline and send them the next time you, reconnect., 206, , Some important (Top 8 ) recommendations for staying, safe and secure when you’re online are listed below;, – Change your password often. The quick act of changing your password can ensure your e-mail remains, private. In addition,passwords that use both letters, and numbers are harder to break., – Don’t share your password. Most e-mail administrators will not ask for your password. Do not be duped, by malicious e-mails asking you for your password., This is a well-known, although not-too-common trick, designed to fool you into sharing your password. As, a rule, never share it with anyone., – Never open attachments from unknown sources., They may contain what are known as “letterbombs” or, “viruses,” which can damage your PC., – Always remember to sign out when you are done. It’s, quick, easy and may save your account from unwanted trespassers. If you are using a public terminal,, at an internet cafe for example, it is advised that you, close the browser you were using when you are ready, to end your Internet session., – Don’t reply to unsolicited messages (“spam”) mail, or, other harassing or offensive mail. By responding, you, only confirm that you are a person with an active email address who can be plagued with constant, unwanted e-mail solicitations. Instead, forward the, unsolicited message to the customer service, department of the source’s e-mail (usually of a form, similar to, abuse@[implicateddomain].com). To, help control spam, Hotmail provides members with, “filters” for incoming mail. These can easily be set up, to send certain messages (such as those that include, certain words) directly to your online trash can., – Make sure that you are using the most up-to-date, Internet software (e.g. browsers such as Microsoft, Internet Explorer or Netscape Navigator). More recent, versions often offer enhanced security protection., – Always use a secure network. Most corporate networks and Internet service providers are protected by, administrators who watch for potential security problems and act to protect users from “hackers” (malicious users) who may try to steal personal information, that is transferred through the network. Although the, risk is small, use caution when on any unfamiliar, network., – Use stations maintained by sources you trust, or ask, if the Internet terminal you are using is protected, against security break-ins., A SMALL LIST OF Search Engines, Yahoo.com (http://www.Yahoo.com), Search.com (http://search.com), EasySearcher (http://www.easysearcher.com), AltaVista (http://www.altavista.com), Excite (http://www.excite.com), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
Page 223 : Google (http://www.google.com), Hotbot (http://www.hotbot.com), Infoseek (http://www.infoseek.com), Lycos (http://www.lycos.com), WebCrawler (http://www.webcrawler.com), www.all4one.com (This useful tool queries four search, engines at once), , Also, MSN has introduced Preview 2 of MSN Explorer as, an integrated client for MSN services, such as MSN, Hotmail. This client allows you to also store Hotmail, locally on your machine. This too reduces the amount of, storage that you need on hotmail., 2 Can I get Hotmail in different languages?, MSN Hotmail can now be viewed in a variety of languages., , www.askjeeves.com (Insted of entering words to search, for, just type in your question), , You can make the language of a Hotmail session match, the language of the Sign In page used to begin that, session. You have your choice of the following languages: English, French, German, Italian, Japanese,, Portuguese (Brazilian), and Spanish, and more to come., , www.rediff.com (Search for anything), , 3 Can I use Hotmail as a business address?, , www.bigfoot.com (Looking for someone’s email address ? Try here), www.hotbot.com (Useful search engine which helps to, find pictures, video or music), , No. You may not use your Hotmail address as your, primary business address. If, however, you work for a, company with which you have an e-mail address and you, want to use your Hotmail account to send and receive email while away from your computer at work, you are, encouraged to do so., , www.indiainfo.com (Info lets you search the web easily), , Example of Prohibited Use:, , www.yahoo.com (Search engine which is also the most, popular), , You are an individual who runs a business. You and your, employees want to use Hotmail accounts rather than, registering and administering your account through a, paid ISP., , www.av.com (Very powerful search engine which gives, plenty of results), , www.sawaal.com (All your questions answered), , mp3.lycos.com (The place to start if you’re after music, files in the mp3 format), www.metacrawler.com (Metacrawler puts your search, through a host different engines), www.mirago.co.uk (A search engine eith an excellent, selection of shopping links), www.webferret.com (One of the easiest way to search, the web), www.indiatimes.com (The portal’s search engine), www.webcrawler.com (Let the webcrawler spider to do, the searching for you), www.indonet.net (Excellent Indian search engine with, loads of useful search catagories), www.satyamonline.com (On ISP’s site and has good, search options), COMPILED LIST OF INTERESTING FAQ’s about, HOTMAIL, 1 How much e-mail storage space do I get with Hotmail?, Hotmail offers 2MB of storage space. If you do not keep, your account below this limit, Hotmail may remove some, messages, which cannot be recovered., If you need additional storage space, there are a few, options. You can use the latest version of Microsoft, Internet Explorer v5 or above, which includes Outlook, Express, which offers you the ability to store e-mails, locally. You can send a blank e-mail message to,
[email protected] for more information on how to, use the beta (pre-release) process to store Hotmail, messages on your local PC, using Outlook Express., , Example of Allowed Use:, You are a businessperson who travels. You have an, account with your company (yourname@your, company.com). You use your Hotmail account to read, and send solicited messages while you are traveling., Hotmail prohibits account sharing. Since Hotmail is, accessible from everywhere in the world, each individual, is able to sign up for his or her own personal account. You, are encouraged to sign up for an account of your own, to, which only you have access. Sharing an account compromises the privacy and security of your e-mail. Each, Hotmail user must have his or her individual e-mail, account., 4 Is my e-mail really private and secure? (SSL)?, Secure connections (often called SSL, or Secure Sockets Layer) is the industry standard in Web security. It is, used primarily for transmitting sensitive information over, the Internet. When you have a secure connection between, your, browser and a Web site, no one else can easily, access the data that you send across the connection., Hotmail uses SSL to encrypt your sign-in name, and, password, when you log in to give you a high level of, security., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished, , 207
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It is Hotmail’s policy to respect the privacy of its users., Therefore, Hotmail will not monitor, edit, or disclose the, contents of a user’s private communications unless, required to do so by law or in the good faith belief that, such action is necessary to:, – conform to the edicts of the law or comply with, legal process served on Hotmail;, – protect and defend the rights or property of, Hotmail; or, – act under exigent circumstances to protect the, personal safety of its users or the public., 5 Can Hotmail protect its users from e-mail viruses?, MSN Hotmail is pleased to offer users McAfee VirusScan, for free. Whenever you receive attachments in your, Hotmail account, it will automatically scan them with, McAfee’s popular VirusScan before downloading., MSN Hotmail recently added the ability to have all, attachments you want to send scanned before they can, be attached to your outgoing e-mail. So before you, upload file to send to another user, it will also be scanned, for viruses before you send it, reducing the spread of, viruses to Hotmail users and the other recipients of your, e-mail., Remember, to ensure safety, Hotmail recommends that, you never open attachments from unknown sources., , You can also accent your messages by using Rich Text, Formatting. The Rich Text Formatting option, also allows, you to add emoticons to your e-mail. This new feature, allows you to add selected symbols or emoticons to your, message. These icons help you convey emotion or add, flair within a message., 7 What does it mean when my account is marked, “inactive”?, Currently, if you do not sign in to your Hotmail account for, 60 days, or if you do not sign-in within the first 10 days,, your account will be marked “inactive.” Stored e-mail and, addresses will be deleted, and inbound mail will be, refused. Your Passport will still function, and your Hotmail, e-mail name will be reserved. To re-activate your account,, simply go to http://www.hotmail.com and enter your, Sign-In name and password. You will then be able to, once again send and receive e-mail using hotmail. If your, account stays “inactive” for over a period of 90 days, it, may be permanently deleted., 8 Can I send and receive attachments on Hotmail?, Yes, you can send and receive as many files as you want, to a message - up to 1MB (1024K) of attachments., Attachments sent to your Hotmail account can be, downloaded to your personal computer by clicking them., GIF and JPEG images and HTML files are automatically, displayed in the browser window., , 6 How do I send images and use e-mail stationery to, make e-mail I send more colorful and fun?, (Emoticons/Stationery/RTF), MSN Hotmail offers users stationery to send fun, colorful, messages to family and friends! Always capture the right, mood for your messages by selecting one of the many, different stationery templates. Use the Stationery Chooser, button on the Compose page to view the available, stationery choices., , 208, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.78, , Chatting, video chatting and using social network sites, Objectives : At the end of this lesson you shall be able to, • explain chating process, • explain video chating process, • explain social network services., Chatting Process, A web chat is a system that allows users to communicate, in real time using easily accessible web interfaces. It is, a type of internet online chat distinguished by its simplicity, and accessibility to users who do not wish to take the, time to install and learn to use specialized chat software., This trait allows users instantaneous access and only a, web browser is required to chat. Users will always get, the latest version of a chat service because no software, installation or updates are required., Video Chat, In video chat video of both caller and receiver can be, seen on screen of both user along with audio. So it gives, an impression of face to face interaction though the caller, and receiver can be thousands of mile apart., Social Networking services, A social networking service is a platform to build social, networks or social relations among people who, share, interests, activities, backgrounds or real-life connections., A social network service consists of a representation of, each user (often a profile), his social links, and a variety, of additional services. Social networking is web-based, services that allow individuals to create a public profile,, to create a list of users with whom to share connection,, and view and cross the connections within the system., Most social network services are web-based and provide, means for users to interact over the Internet, such as email and instant messaging.Social network sites are, varied and they incorporate new information and, communication tools such as, mobile connectivity, photo/, video/sharing and blogging. Online community services, , are sometimes considered as a social network service,, though in a broader sense, social network service usually, means an individual-centered service whereas online, community services are group-centered. Social, networking sites allow users to share ideas, pictures,, posts, activities, events, interests with people in their, network., The main types of social networking services are those, that contain category places (such as former school year, or classmates), means to connect with friends (usually, with self-description pages), and a recommendation, system linked to trust. Popular methods now combine, many of these, with American-based services such as, Facebook, Google+,YouTube, LinkedIn, Instagram,, Pinterest, Tumblr and Twitter widely used worldwide;, Nexopia in Canada; Badoo, Bebo, Vkontakte (Russia),, Delphi (also called Delphi Forums), Draugiem.lv (mostly, in Latvia), Hi5 (Europe), Hyves (mostly in The, Netherlands), iWiW (mostly in Hungary), Nasza-Klasa,, Soup (mostly in Poland), Glocals in Switzerland,Skyrock,, The Sphere, StudiVZ (mostly in Germany), Tagged,, Tuenti (mostly in Spain), and XING in parts of Europe;, Hi5 and Orkut in South America and Central America;, Mxit in Africa; and Cyworld, Mixi, Orkut, renren, weibo, and Wretch in Asia and the Pacific Islands., There have been attempts to standardize these services, to avoid the need to duplicate entries of friends and, interests (see the FOAF standard and the Open Source, Initiative). According to experts, the largest social, networking users are Asian-Pacific regions with 615,9, million people. A 2013 survey found that 73% U.S adults, use social networking sites., , Copyright @ NIMI Not to be Republished, , 209
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.79, , Explaining threats to computers connected to Internet & process of protecting computers from it., Objectives : At the end of this lesson you shall be able to, • explain threats to computers connected to Internet, • process of Protecting computers from Internet., A web threat is any threat that uses the World Wide Web, to facilitate cybercrime. Web threats use multiple types, of malware and fraud, all of which utilize HTTP or HTTPS, protocols, but may also employ other protocols and components, such as links in email or IM, or malware attachments or on servers that access the Web. They benefit, cybercriminals by stealing information for subsequent, sale and help absorb infected PCs into botnets., Web threats pose a broad range of risks, including financial damages, identity theft, loss of confidential information/data, theft of network resources, damaged, brand/personal reputation, and erosion of consumer confidence in e-commerce and online banking., It is a type of threat related to information technology, (IT). The IT risk, i.e. risk affecting has gained and increasing impact on society due to the spread of IT processes., Web threats can be divided into two primary categories,, based on delivery method - push and pull. Push-based, threats use spam, phishing, or other fraudulent means, to lure a user to a malicious (often spoofed) website which, then collects information and/or injects malware. Push, attacks use phishing, DNS poisoning (or pharming), and, other means to appear to originate from a trusted source., Precisely-targeted push-based web threats are often referred to as spear phishing to reflect the focus of their, data gathering attack. Spear phishing typically targets, specific individuals and groups for financial gain. In other, push-based web threats, malware authors use social engineering such as enticing subject lines that reference, holidays, popular personalities, sports, pornography,, world events and other hot topics to persuade recipients, to open the email and follow links to malicious websites, or open attachments with malware that accesses the, Web., Pull-based web threats are often referred to as "driveby" threats by experts (and more commonly as "driveby downloads" by journalists and the general public),, since they can affect any website visitor. Cybercriminals, infect legitimate websites, which unknowingly transmit, malware to visitors or alter search results to take users, to malicious websites. Upon loading the page, the user's, browser passively runs a malware downloader in a hidden HTML frame (IFRAME) without any user interaction., , 210, , Internet security, Internet security is a tree branch of computer security, specifically related to the Internet, often involving browser, security but also network security on a more general level, as it applies to other applications or operating systems, on a whole. Its objective is to establish rules and measures to use against attacks over the Internet. The, Internet represents an insecure channel for exchanging, information leading to a high risk of intrusion or fraud,, such as phishing. Different methods have been used to, protect the transfer of data, including encryption., Types of security, Network layer security, TCP/IP which stands for Transmission Control Protocol, (TCP) and Internet Protocol (IP) aka Internet protocol, suite can be made secure with the help of cryptographic, methods and protocols. These protocols include Secure, Sockets Layer (SSL), succeeded by Transport Layer, Security (TLS) for web traffic, Pretty Good Privacy (PGP), for email, and IPsec for the network layer security., Internet Protocol Security (IPsec), This protocol is designed to protect communication in a, secure manner using TCP/IP aka Internet protocol suite., It is a set of security extensions developed by the Internet, Task force IETF, and it provides security and authentication at the IP layer by transforming data using encryption. Two main types of transformation that form the basis, of IPsec: the Authentication Header (AH) and ESP. These, two protocols provide data integrity, data origin authentication, and anti-replay service. These protocols can be, used alone or in combination to provide the desired set, of security services for the Internet Protocol (IP) layer., The basic components of the IPsec security architecture are described in terms of the following functionalities:, •, , Security protocols for AH and ESP, , •, , Security association for policy management and traffic processing, , •, , Manual and automatic key management for the, internet key exchange (IKE), , •, , Algorithms for authentication and encryption, , Copyright @ NIMI Not to be Republished
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The set of security services provided at the IP layer, includes access control, data origin integrity, protection, against replays, and confidentiality. The algorithm allows, these sets to work independently without affecting other, parts of the implementation. The IPsec implementation, is operated in a host or security gateway environment, giving protection to IP traffic., Security token, Some online sites offer customers the ability to use a, six-digit code which randomly changes every 30-60, seconds on a security token. The keys on the security, token have built in mathematical computations and, manipulate numbers based on the current time built into, the device. This means that every thirty seconds there, is only a certain array of numbers possible which would, be correct to validate access to the online account. The, website that the user is logging into would be made aware, of that devices' serial number and would know the, computation and correct time built into the device to verify, that the number given is indeed one of the handful of, six-digit numbers that works in that given 30-60 second, cycle. After 30-60 seconds the device will present a new, random six-digit number which can log into the website., Electronic mail security (E-mail), Background, Email messages are composed, delivered, and stored, in a multiple step process, which starts with the message's, composition. When the user finishes composing the, message and sends it, the message is transformed into, a standard format: an RFC 2822 formatted message., Afterwards, the message can be transmitted. Using a, network connection, the mail client, referred to as a mail, user agent (MUA), connects to a mail transfer agent, (MTA) operating on the mail server. The mail client then, provides the sender's identity to the server. Next, using, the mail server commands, the client sends the recipient, list to the mail server. The client then supplies the, message. Once the mail server receives and processes, the message, several events occur: recipient server, identification, connection establishment, and message, transmission. Using Domain Name System (DNS), services, the sender's mail server determines the mail, server(s) for the recipient(s). Then, the server opens up, a connection(s) to the recipient mail server(s) and sends, the message employing a process similar to that used, by the originating client, delivering the message to the, recipient(s)., Pretty Good Privacy (PGP), Pretty Good Privacy provides confidentiality by, encrypting messages to be transmitted or data files to, be stored using an encryption algorithm such Triple DES, or CAST-128. Email messages can be protected by using, cryptography in various ways, such as the following:, •, , Signing an email message to ensure its integrity and, confirm the identity of its sender., , •, , Encrypting the body of an email message to ensure, its confidentiality., , •, , Encrypting the communications between mail servers, to protect the confidentiality of both message body, and message header., , The first two methods, message signing and message, body encryption, are often used together; however,, encrypting the transmissions between mail servers is, typically used only when two organizations want to protect, emails regularly sent between each other. For example,, the organizations could establish a virtual private network, (VPN) to encrypt the communications between their mail, servers over the Internet. Unlike methods that can only, encrypt a message body, a VPN can encrypt entire, messages, including email header information such as, senders, recipients, and subjects. In some cases,, organizations may need to protect header information., However, a VPN solution alone cannot provide a, message signing mechanism, nor can it provide, protection for email messages along the entire route from, sender to recipient., Multipurpose Internet Mail Extensions (MIME), MIME transforms non-ASCII data at the sender's site to, Network Virtual Terminal (NVT) ASCII data and delivers, it to client's Simple Mail Transfer Protocol (SMTP) to be, sent through the Internet. The server SMTP at the, receiver's side receives the NVT ASCII data and delivers, it to MIME to be transformed back to the original nonASCII data., Message Authentication Code, A Message authentication code (MAC) is a cryptography, method that uses a secret key to encrypt a message., This method outputs a MAC value that can be decrypted, by the receiver, using the same secret key used by the, sender. The Message Authentication Code protects both, a message's data integrity as well as its authenticity., Firewalls, A firewall (computing) controls access between networks., It generally consists of gateways and filters which vary, from one firewall to another. Firewalls also screen, network traffic and are able to block traffic that is, dangerous. Firewalls act as the intermediate server, between SMTP and Hypertext Transfer Protocol (HTTP), connections., Role of firewalls in web security, Firewalls impose restrictions on incoming and outgoing, Network packets to and from private networks. Incoming, or outgoing traffic must pass through the firewall; only, authorized traffic is allowed to pass through it. Firewalls, create checkpoints between an internal private network, and the public Internet, also known as choke, points(borrowed from the identical military term of a, combat limiting geographical feature). Firewalls can, create choke points based on IP source and TCP port, number. They can also serve as the platform for IPsec., Using tunnel mode capability, firewall can be used to, implement VPNs. Firewalls can also limit network, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.04, , Copyright @ NIMI Not to be Republished, , 211
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exposure by hiding the internal network system and, information from the public Internet. Also, WE HAVE A, LOT OF BIG WAYE to deal with it., Types of firewalls, Packet filter, , Ransomware and Scareware, Botnet, A botnet is a network of zombie computers that have, been taken over by a robot or bot that performs largescale malicious acts for the creator of the botnet., , A packet filter is a first generation firewall that processes, network traffic on a packet-by-packet basis. Its main job, is to filter traffic from a remote IP host, so a router is, needed to connect the internal network to the Internet., The router is known as a screening router, which screens, packets leaving and entering the network., , Spyware, , Stateful packet inspection, , A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to, make a computer resource unavailable to its intended, users. Although the means to carry out, motives for, and, targets of a DoS attack may vary, it generally consists of, the concerted efforts to prevent an Internet site or service from functioning efficiently or at all, temporarily or, indefinitely., , In a stateful firewall the circuit-level gateway is a proxy, server that operates at the network level of an Open, Systems Interconnection (OSI) model and statically defines what traffic will be allowed. Circuit proxies will forward Network packets (formatted unit of data ) containing a given port number, if the port is permitted by the, algorithm. The main advantage of a proxy server is its, ability to provide Network Address Translation (NAT),, which can hide the user's IP address from the Internet,, effectively protecting all internal information from the, Internet., Application-level gateway, An application-level firewall is a third generation firewall, where a proxy server operates at the very top of the OSI, model, the IP suite application level. A network packet is, forwarded only if a connection is established using a, known protocol. Application-level gateways are notable, for analyzing entire messages rather than individual, packets of data when the data are being sent or received., Malicious software, Malware, A computer user can be tricked or forced into downloading software onto a computer that is of malicious intent., Such programs are known as malware and come in many, forms, such as viruses, Trojan horses, spyware, and, worms. Malicious software is sometimes used to form, botnets., Viruses, Computer Viruses are programs that can replicate their, structures or effects by infecting other files or structures, on a computer. The common use of a virus is to take, over a computer to steal data., Worms, Computer worms are programs that can replicate themselves throughout a computer network, performing malicious tasks throughout., Trojan horse, A Trojan horse commonly known as a Trojan is a general term for malicious software that pretends to be harmless, so that a user willingly allows it to be downloaded, onto the computer., 212, , The term spyware refers to programs that surreptitiously, monitor activity on a computer system and report that, information to others without the user's consent., Denial-of-service attack, , Browser choice, Web browser statistics tend to affect the amount a Web, browser is exploited. For example, Internet Explorer 6,, which used to own a majority of the Web browser market share, is considered extremely insecure because vulnerabilities were exploited due to its former popularity., Since browser choice is more evenly distributed (Internet, Explorer at 28.5%,Firefox at 18.4%, Google Chrome at, 40.8%, and so on) and vulnerabilities are exploited in, many different browsers., Application vulnerabilities, Applications used to access Internet resources may contain security vulnerabilities such as memory safety bugs, or flawed authentication checks. The most severe of, these bugs can give network attackers full control over, the computer. Most security applications and suites are, incapable of adequate defense against these kinds of, attacks., Internet security products, Antivirus, Antivirus programs and Internet security programs can, protect a programmable device from malware by detecting and eliminating viruses; Before 2000 a user would, pay for antivirus software, 10 years later however, computer users can choose from a host of free security applications on the Internet., Security Suites, So called "security suites" were first offered for sale in, 2003 (McAffee) and contain a suite of firewalls, anti-virus, anti-spyware and more.They may now offer theft, protection, portable storage device safety check, private, internet browsing, cloud anti-spam, a file shredder or, make security-related decisions (answering popup windows) and several were free of charge as of at least, 2012., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.79, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.80 & 1.11.81, , Outlook Express & Google+, Objectives : At the end of this lesson you shall be able to, • explain outlook express, • explain Google+, Microsoft Outlook, , Creation, , Microsoft Outlook is a personal information manager from, Microsoft, available as a part of the Microsoft, Officesuite.Although often used mainly as an email, application, it also includes a calendar, task manager,, contact manager,note taking, journal, and web browsing.It, can be used as a stand-alone application, or can work, with Microsoft Exchange Server and Microsoft, SharePoint Server for multiple users in an organization,, such as shared mailboxes and calendars, Exchange, public folders, SharePoint lists, and meeting schedules., There are third-party add-on applications that integrate, Outlook with devices such as BlackBerry mobile phones, and with other software such as Office and Skypeinternet, communication. Developers can also create their own, custom software that works with Outlook and Office, components using Microsoft Visual Studio. In addition,, Windows Mobile devices can synchronize almost all, Outlook data to Outlook Mobile., , Google launched the Google+ service as an invitationonly "field test" on June 28, 2011, but soon suspended, early invites due to an "insane demand" for new accounts., On August 6, each Google+ member had 150 invitations to give outuntil September 20, 2011, when Google+, opened to everyone 18 years of age or older without the, need for an invitation. It was opened for a younger age, group (13 years or older in US and most countries, 14 or, older in South Korea and Spain, 16 or older in the Netherlands) on January 26, 2012. Google+ is available as a, website and on mobile devices., , Google+, Google+ (pronounced and sometimes written as Google, Plus) is a social networking and identity service that is, owned and operated by Google Inc. Google has described Google+ as a "social layer" that enhances many, of its online properties, and that it is not simply a social, networking website, but also an authorship tool that associates web-content directly with its owner/author. It is, the second-largest social networking site in the world, after Facebook. 540 million monthly active users are, part of the Identity service site, by interacting socially with, Google+'s enhanced properties, like Gmail, +1 button, and, YouTube comments. In October 2013, Google counted, 540 million active users who used at least one Google+, service, of which 300 million users are active in "the, stream"., , Before the launch, Google referred to Google+ as Google, Circles, a name alluding to its emphasis on organising, friendship information. Google+ is considered the, company's fourth foray into social networking, following, Google Buzz (launched 2010, retired in 2011), Google, Friend Connect (launched 2008, retired by March 1,, 2012) and Orkut (launched in 2004, as of 2013 operated, entirely by subsidiary Google Brazil). Sources such as, The New York Times have declared it Google's biggest, attempt to rival the social network Facebook, which has, over 1 billion users., , Copyright @ NIMI Not to be Republished, , 213
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IT & ITES, Related Theory for Exercise 1.12.82 to 1.12.92, COPA - Designing Static WebPages, Web designing, Objectives : At the end of this lesson you shall be able to, • explain web sites and web pages, • explain static and dynamic web pages, • explain HTML, DHTML and XML, • explain the concept of web hosting, web server, application server and database server., Introduction, The World Wide Web (WWW) was created in 1990 by, CERN physicist Tim Berners-Lee. On 30 April 1993,, CERN announced that the World Wide Web would be, free to use for anyone. Before the introduction of HTML, and HTTP, other protocols such as File Transfer Protocol, and the Gopher Protocol were used to retrieve individual, files from a server. These protocols offer a simple directory, structure which the user navigates and chooses files to, download. Documents were most often presented as plain, text files without formatting, or were encoded in word, processors formats., Websites, A website, also written as Web site, web site, or simply, site, is a set of related web page containing content, (media) such as written language, Image, video, sound,, etc. A website is hosted on at least one web server,, accessible via a network such as the internet or a private, local area network through an Internet address known, as a uniform resource locator. All publicly accessible, websites collectively constitute the world wide web., A webpage is a document, typically written in plain text, interspersed with formatting instructions of Hypertext, Mark-up Language (HTML) XHTML. A webpage may, incorporate elements from other websites with suitable, HTML anchor., Web pages are accessed and transported with the, Hypertext Transfer Protocol (HTTP), which may optionally, employ encryption secure, HTTPS to provide security and, privacy for the user of the webpage content. The user's, application, often a web browser, renders the page content, according to its HTML Mark-up instructions onto a, Computer monitor., The pages of a website can usually be accessed from a, simple Uniform Resource Locator (URL) called the web, address. The URLs of the pages organize them into a, hierarchy, although hyperlink between them conveys the, reader's perceived sitemap and guides the reader's, navigation of the site which generally includes a Home, page with most of the links to the site's web content, and, a supplementary about page, contact page and link page., , 214, , Some websites require a subscription to access some or, all of their content. Examples of subscription websites, include many business sites, parts of news websites,, Academic journal websites, gaming websites, file-sharing, websites, Internet forum, web-based Email, Social, networking websites, websites providing real-time Stock, market data, and websites providing various other, services (e.g., websites offering storing and/or sharing, of images, files and so forth)., A website may be, •, , Personal website, , •, , Commercial website, , •, , E-Government, , •, , Non-profit organization website., , Static Website, A static website is one that has web pages stored on the, server in the format that is sent to a client web browser. It, is primarily coded in Hypertext Markup Language (HTML)., Simple forms or marketing examples of websites, such, as classic website, a five-page website or a brochure, website are often static websites, because they present, pre-defined, static information to the user. This may, include information about a company and its products, and services through text, photos, animations, audio/video, and interactive menus and navigation., This type of website usually displays the same information, to all visitors. Similar to handing out a printed brochure to, customers or clients, a static website will generally provide, consistent, standard information for an extended period of, time. Although the website owner may make updates, periodically, it is a manual process to edit the text, photos, and other content and may require basic website design, skills and software., Advantages, •, , Static Websites are easier to develop, , •, , Can be developed quickly, , •, , They are indexed easily by search engines as all the, web pages actually exist on the server, which is not, the case with dynamic websites., , Copyright @ NIMI Not to be Republished
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Disadvantages, , •, , Content Site: these sites create and sell of original, content to end-user. (e.g., Slate, About.com)., , •, , Static websites cannot do complex tasks required by, many online services., , •, , •, , Updating a whole site can be cumbersome and time, consuming., , Corporate website: used to provide information regarding, business, organization, or service., , •, , •, , An isolation of Data and Design is not provided in static, websites., , Commerce site (or eCommerce site): these sites are, designed for purchasing or selling goods, such as, Amazon.com, CSN Stores, and Overstock.com., , •, , Community site: sites where persons with similar, interests communicate to each other through chatting, and messaging or through soci message boards, such, as MySpace or Facebook., , •, , City Site: A site that shows information about a certain, city or town and events that takes place in that town., Usually created by the city council. For example,, Richmond.com is the geodomain for Richmond,, Virginia., , •, , Information site: contains content that is intended to, inform visitors, but not necessarily for commercial, purposes, such as: RateMyProfessors.com, Free, Internet Lexicon and Encyclopaedia. Most, government, educational and non-profit institutions, have an informational site., , •, , Mirror site: A complete reproduction of a website., , •, , News site: similar to an information site, but dedicated, to dispensing news and commentary., , •, , Personal homepage: run by an individual or a small, group such as a family that contains information or, any content that the individual wishes to include. These, are usually uploaded using a web hosting service such, as Geocities., , •, , Phish Site: a website created to fraudulently acquire, sensitive information, such as passwords and credit, card details, by disguising as a trustworthy person or, business (such as Social Security Administration,, PayPal) in an electronic communication., , •, , Political site: A site on which people may voice political, views., , •, , Rating site: A site on which people can praise or, disparage what is featured., , •, , Review site: A site on which people can post reviews, for products or services., , •, , School site: a site on which teachers, students, or, administrators can post information about current, events at or involving their school., , •, , Video sharing: A site that enables user to upload, videos, such as YouTube and Google Video., , •, , Search engine site: a site that provides general, information and is intended as a gateway for retrieving, other sites. Google, Yahoo and MSN are the most, widely known search engines., , •, , Shock site: includes images or other material that is, intended to be offensive to most viewers (e.g., rotten.com)., , Dynamic Website, A dynamic website is one that changes or customizes, itself frequently and automatically, based on certain, criteria., Dynamic websites can have two types of dynamic activity:, Code and Content. Dynamic code is invisible or behind, the scenes and dynamic content is visible or fully displayed, Advantages, •, , Can do more complex task required by online services., , •, , They are easier to update., , •, , Isolation of data and design allows programmers and, content writers to work independently., , Disadvantages, •, , Can take more time to build., , •, , Can be difficult to build., , •, , Dynamic websites are not indexed by search engines, easily, since they do not have actual web pages, present on the web server. With continuous, improvements in search engine technology, this, problem is now very much eliminated and you can, find that many dynamic websites are very well indexed, by search engines now a days., , A few such classifications are:, •, , •, , •, , Affiliate: enabled portal that renders not only its custom, CMS but also syndicated content from other content, providers for an agreed fee. There are usually three, relationship tiers. Affiliate Agencies (e.g., Commission, Junction), Advertisers (e.g., eBay) and consumer (e.g.,, Yahoo!)., Archive site: used to preserve valuable electronic, contents that are on verge of extinction. For examples:, Internet Archive, which since 1996 has preserved, billions of old and new web pages; and Google Groups,, which in early 2005 had preserved over 845,000,000, messages posted to Usenet news/discussion groups., Blog Site: sites generally used to post online diaries,, comments or views that may include discussion, forums (e.g., blogger, Xanga)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 215
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•, , Warez: a site designed to host and let users download, copyrighted materials illegally., , •, , Web portal: a site is vehicle that provides a gateway to, other resources on the Internet or an intranet., , Web Pages, A web page or webpage is a Document or information, resource that is suitable for the world wide Web and can, be accessed through a web browser and displayed on a, computer display or mobile device. This information is, usually in HTML or XHTML format, and may provide, navigation bar to other web pages via Hyper text Hyper, link. Web pages frequently subsume other resources such, as Cascading Style Sheet, Client-side-scripting and, Images into their final presentation., Web pages may be retrieved from a local computer or, from a remote Web server. The web server may restrict, access only to a private network, e.g. a corporate Intranet, or it may publish pages on the World Wide Web. Web, pages are requested and served from web. Web server, using Hypertext Transfer Protocol (HTTP)., Web pages may consist of files of static text and other, Web content stored within the Web server 's file, system(Static Web page), or may be constructed by, Server-side scripting when they are requested (Dynamic, web page). Client-side scripting can make web pages more, responsive to user input once on the client browser., , Web Browser, A Web browser can have a Graphical User Interface, like, Internet Explorer, Mozilla Firefox, Google Chrome and, Opera (web browser), or can be Command Line Interface,, like Lynx (web browser) (Fig 1) or Links (web browser)., Web users with disabilities often use assistive, technologies and adaptive strategies to Web accessibility, web pages. Users may be colour blind, may or may not, want to use a mouse perhaps due to repetitive stress, injury or motor-neurone problems, may be deaf and, require audio to be captioned, may be blind and using a, Screen reader or display, may need screen magnification,, etc. Disabled and able-bodied users may disable the, download and viewing of images and other media, to, save time, network bandwidth or merely to simplify their, browsing experience., Users of mobile devices often have restricted displays and, bandwidth. Anyone may prefer not to use the fonts, font, sizes, styles and colour schemes selected by the web, page designer and may apply their own CSS styling to, the page. The World Wide Web Consortium (W3C) and, Web Accessibility Initiative (WAI) recommend that all web, pages should be designed with all of these options in mind., , Fig 1, , 216, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Downloading a Software from Internet, 1 Create a Temporary Files folder by opening My, Computer, double click on your hard drive (typically, the C: drive), then select File/New/Folder as on Fig 2., Fig 2, , 2 Type "Temporary File" and name it as on Fig 3., , Fig 3, , 3 Type "My SQL 5. 1 free download " from freeware, software website on internet., Note: As an example Choose "http://, dev.mysql.com/downloads/" select "My SQL, Community server" in download from the, opened site as on Fig 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 217
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Fig 4, , My Sql Community, , 4 Click "MySQL Community Server 5.1 " from looking for previous version option as on Fig 5, Fig 5, , 5 Choose "Windows (x86, 32-bit), MSI Installer Essentials - Recommended" and click download (Fig.6)., , 218, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 6, , Note: Save the "My SQL 5.1.63" in the created, Folder name " Temporary Folder", , documents (hypertext) and make web documents, interactive (such as with forms)., , 6 Burn the Downloaded "My SQL 5.1.63" in a CD ROM, for Installation., , HTML is a defined standard markup language. That, standard was developed by the World Wide Web, Consortium (W3C). It is based upon SGML (Standard, Generalized Markup Language). It is a language that uses, tags to define the structure of your text. Elements and, tags are defined by the < and > characters., , WEB LANGUAGES, Web languages are called as Markup languages are, designed for the processing, definition and presentation, of text. The language specifies code for formatting, both, the layout and style, within a text file. The code used to, specify the formatting are called tags, Four Types of Markup languages, 1 BML, , DHTML, Dynamic HTML is not really a new specification of HTML,, but rather a new way of looking at and controlling the, standard HTML codes and commands., When thinking of dynamic HTML, we need to remember, the qualities of standard HTML, especially that once a, page is loaded from the server, it will not change until, another request comes to the server. Dynamic HTML give, more control over the HTML elements and allows them, to change at any time, without returning to the Web server., , 2 HTML, 3 DHTML, 4 XML, BML (Better markup language), BML is essentially a simple macro language. Macros are, called blocks in BML. Blocks are defined in look files, and, are invoked in BML files. Blocks accept parameters and, are divided into several types, according to how parameters, are transmitted and how the definition of the block is able, to make use of them., HTML (Hyper text markup Language), HTML or HyperText Markup Language is the language of, the web. All web pages are written in HTML. HTML defines, the way that images, multimedia, and text are displayed, in web browsers. It includes elements to connect the, , There are four parts to DHTML:, •, •, •, •, , Document Object Model (DOM) (definition), Scripts, Cascading Style Sheets (CSS), XHTML, , DOM, The DOM is allows to access any part of Web page to, change it with DHTML. Every part of a Web page is, specified by the DOM and using its consistent naming, conventions can access them and change their properties., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 219
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Scripts, , Data binding, , Scripts written in either JavaScript or ActiveX are the two, most common scripting languages used to activate, DHTML. You use a scripting language to control the, objects specified in the DOM., , This is an IE only feature. Microsoft developed this to allow, easier access to databases from Web sites. It is very, similar to using a CGI to access a database, but uses an, ActiveX control to function., , Cascading Style Sheets, , XML, , CSS is used in DHTML to control the look and feel of the, Web page. Style sheets define the colors and fonts of, text, the background colors and images, and the, placement of objects on the page. Using scripting and, the DOM, we can change the style of various elements., , Extensible Markup Language (XML) is a markup language, that defines a set of rules for encoding documents in a, format that is bothhuman-readable and machine-readable., It is defined in the XML 1.0 Specification produced by the, W3C, and several other related specifications, all gratis, open standards. The design goals of XML emphasize, simplicity, generality, and usability over the Internet. It is a, textual data format with strong support via Unicode for the, languages of the world. Although the design of XML focuses, on documents, it is widely used for the representation of, arbitrary data structures, for example in web services, , XHTML, XHTML or HTML 4.x is used to create the page itself and, build the elements for the CSS and the DOM to work on., There is nothing special about XHTML for DHTML - but, having valid XHTML is even more important, as there, are more things working from it than just the browser., Features of DHTML, , Creating an HTML document, , There are four primary features of DHTML:, , Before start writing code to write a web page, it is a good, practice to plan ahead the appearance of the web page., An HTML document has two elements:, , 1 Changing the tags and properties, , 1 Document Content, , 2 Real-time positioning, , 2 Tags, , 3 Dynamic fonts (Netscape Communicator), 4 Data binding (Internet Explorer), Changing the tags and properties, This is one of the most common uses of DHTML. It allows, to change the qualities of an HTML tag depending on an, event outside of the browser (such as a mouse click, time,, or date, and so on). we can use this to preload information, onto a page, and not display it unless the reader clicks, on a specific link., Real-time postioning, Objects, images, and text moving around the Web page., This can allow we to play interactive games with the, readers or animate portions of the screen., Dynamic Fonts, This is a Netscape only feature. Netscape developed this, to get around the problem designers had with not knowing, what fonts would be on a reader's system. With dynamic, fonts, the fonts are encoded and downloaded with the page,, so that the page always looks how the designer intended, it to., , 220, , Document content is the information on a web page, that the user will see. That information could be text or, graphics., Tags are the HTML codes that control how the document, content will appear. The tags, in other words, will, determine whether the text will be bold, black or blue, or, of font type Time New Roman or Airal., Start Notepad, To start Notepad go to:, Start, All Programs, Accessories, Notepad, Edit Your HTML with Notepad (Fig 7), Type your HTML code into your Notepad:, Save Your HTML, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 7, , Select Save as.. in Notepad's file menu., When you save an HTML file, you can use either the .htm, or the .html file extension., Save the file in a folder that is easy to remember, , Start your web browser and open your html file from the, File, Open menu, or just browse the folder and doubleclick your HTML file., The result should look much like this: (Fig 8), , Run the HTML in Your Browser, Fig 8, , Structure of Markup Language, An HTML document has two* main parts:, 1 head. The head element contains title and meta data, of a web document., 2 body. The body element contains the information that, you want to display on a web page., , To make your web pages compatible with HTML 4, you, need to add a document type declaration (DTD) before the, HTML element. Many web authoring software add DTD, and basic tags automatically when you create a new web, page., In a web page, the first tag (specifically, <html>) indicates, the markup language that is being used for the document., The <head> tag contains information about the web page., Lastly, the content appears in the <body> tag. (Fig 9), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 221
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Fig 9, , The <!DOCTYPE> Declaration, There are many different documents on the web. A browser, can only display a document correctly, if it knows what, kind of document it is., There are also many different versions of HTML, and a, browser can only display an HTML page 100% correctly, if it knows the exact HTML version used in the page. This, is what <!DOCTYPE> is used for., , •, , Provides a title for the page when it is added to, favorites., , •, , Displays a title for the page in search-engine results., , HTML Element Syntax, •, , An HTML element starts with a start tag / opening tag, , •, , An HTML element ends with an end tag / closing tag, , •, , <!DOCTYPE> is not an HTML tag. It is an information (a, declaration) to the browser about what version the HTML, is written in., , The element content is everything between the start, and the end tag, , •, , Some HTML elements have empty content, , •, , Empty elements are closed in the start tag, , The HTML <head> Element, , •, , Most HTML elements can have attributes, , The <head> element is a container for all the head, elements. Elements inside <head> can include scripts,, instruct the browser where to find style sheets, provide, meta information, and more., The following tags can be added to the head section: <title>,, <base>, <link>, <meta>, <script>, and <style>., , HTML Headings, HTML headings are defined with the <h1> to <h6> tags., Examples, <html>, <body>, <h1>This is heading 1</h1>, , The HTML <title> Element, The <title> tag defines the title of the document., , <h2>This is heading 2</h2>, <h3>This is heading 3</h3>, , The title element is required in all HTML/XHTML, documents., , <h4>This is heading 4</h4>, , The title element:, , <h6>This is heading 6</h6>, , •, , Defines a title in the browser toolbar., , 222, , <h5>This is heading 5</h5>, </body>, </html>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 239 : Result, , Fig 10, , This is heading 1, This is heading 2, This is heading 3, This is heading 4, This is heading 5, This is heading 6, HTML Paragraphs, HTML paragraphs are defined with the <p> tag., , HTML Attributes, , <html>, , •, , HTML elements can have attributes, , <body>, , •, , Attributes provide additional information about an, element, , <p>This is a paragraph.</p>, , •, , Attributes are always specified in the start tag, , <p>This is a paragraph.</p>, , •, , Attributes come in name/value pairs like:, name="value", , <p>This is a paragraph.</p>, , </body>, </html>, , Attribute Example, , Examples, This is a paragraph., , HTML links are defined with the <a> tag. The link address, is specified in the href attribute:, , This is a paragraph., , <html>, , This is a paragraph., , <body>, , HTML Links, , <a href="http://www.yahoo.com">, , HTML links are defined with the <a> tag., , This is a link</a>, , <html>, , </body>, , <body>, , </html>, , <a href="http://www.facebook.com">, , Result, , This is a link</a>, , This is the link, , </body>, , By clicking the link yahoo home page appears (Fig 11)., , </html>, , Formatting, , Result, , Create Line Breaks - The <br /> Element:, , This is a link, By clicking the link it shows the facebook login page, HTML Images, HTML images are defined with the <img> tag., , Whenever the <br /> element, anything following it starts, on the next line. This tag is an example of an empty, element, where you do not need opening and closing tags,, as there is nothing to go in between them., , <html>, <body>, <img src="w3schools.jpg" width="104" height="142" />, </body>, </html>, Result (Fig 10), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 223
Page 240 : Fig 11, , Example:, , Soft Hyphens:, , Hello<br/>, You come most carefully upon your hour.<br/>, Thanks<br/>, , <p style="text-align: justify;"> The morbid fear of, the number 13, or triskaidekaphobia, has plagued, some important historic figures like Mahamiya and, Nanao.</p>, , Mahnaz, Result, , This will produce following result:, , Hello, You come most carefully upon your hour., Thanks, Mahnaz, , Example for soft hyphen - The morbid fear of the, number 13, or triskaidekaphobia, has plagued some, important historic figures like Mahamiya and Nanao., Preserve Formatting - The <pre> Element:, , To Become, Centring Content - The <center> Element:, You can use <center> tag to put any content in the center, of the page or any table cell., Example:, <p>This is not in the center.</p>, <center>, <p>This is in the center.</p>, </center>, This will produce following result:, This is not in the center., This is in the center., , 224, , Occasionally, you will want to allow a browser to hyphenate, long words to better justify a paragraph. For example,, consider the following code and its resulting output., , Sometimes you want your text to follow the exact format, of how it is written in the HTML document. In those cases,, you can use the preformatted tag (<pre>)., Any text between the opening <pre> tag and the closing, </pre> tag will preserve the formatting of the source, document., <pre>, function testFunction( strText ){, alert (strText), }, </pre>, This will produce following result:, function testFunction( strText ){, alert (strText), }, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 241 : Horizontal Rules - The <hr /> Element, , Underlined Text - The <u> Element:, , Horizontal rules are used to visually break up sections of, a document. The <hr> tag creates a line from the current, position in the document to the right margin and breaks, the line accordingly., , Anything that appears in a <u>...</u> element is displayed, with underline, like the word underlined here:, , For example you may want to give a line between two, paragraphs as follows:, , <p>The following word uses a <u>underlined</, u> typeface.</p>, This will produce following result:, , <p>This is paragraph one and should be on top</p>, , The following word uses a underlined typeface., , <hr />, , Strike Text - The <strike> Element:, , <p>This is paragraph two and should be at bottom</, p>, This will produce following result:, This is paragraph one and should be on top, This is paragraph two and should be at bottom, Again <hr /> tag is an example of an empty element,, where you do not need opening and closing tags, as there, is nothing to go in between them., Note: The <hr /> element has a space between, the characters hr and the forward slash. If you, omit this space, older browsers will have, trouble rendering the line break, while if you, miss the forward slash character and just use, <hr> it is not valid XHTML, Presentational Tags:, If you use a word processor, you are familiar with the, ability to make text bold, italicized, or underlined; these, are just three of the ten options available to indicate how, text can appear in HTML and XHTML., Bold Text - The <b> Element:, Anything that appears in a <b>...</b> element is displayed, in bold, like the word bold here:, <p>The following word uses a <b>bold</b>, typeface.</p>, This will produce following result:, The following word uses a bold typeface., Italic Text - The <i> Element:, Anything that appears in a <i>...</i> element is displayed, in italicized, like the word italicized here:, <p>The following word uses a <i>italicized</i>, typeface.</p>, This will produce following result:, The following word uses a italicized typeface., , Anything that appears in a <strike>...</strike> element is, displayed with strikethrough, which is a thin line through, the text:, <p>The, following, word, uses, a, <strike>strikethrough</strike> typeface.</p>, This will produce following result:, The following word uses a strikethrough typeface., Monospaced font - The <tt> Element:, The content of a <tt> element is written in monospaced, font. Most fonts are known as variable-width fonts, because different letters are of different widths (for, example, the letter m is wider than the letter i). In a, monospaced font, however, each letter is the same width., <p>The, following, word, uses, <tt>monospaced</tt> typeface.</p>, , a, , This will produce following result:, The following word uses a monospaced typeface., Superscript Text - The <sup> Element:, The content of a <sup> element is written in superscript;, the font size used is the same size as the characters, surrounding it but is displayed half a character.s height, above the other characters., <p>The, following, word, uses, <sup>superscript</sup> typeface.</p>, , a, , This will produce following result:, The following word uses a superscript typeface., Subscript Text - The <sub> Element:, The content of a <sub> element is written in subscript;, the font size used is the same as the characters surrounding, it, but is displayed half a character.s height beneath the, other characters., <p>The, following, word, uses, <sub>subscript</sub> typeface.</p>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , a, , 225
Page 242 : This will produce following result:, The following word uses a subscript typeface., Larger Text - The <big> Element:, The content of the <big> element is displayed one font, size larger than the rest of the text surrounding it., <p>The following word uses a <big>big</big>, typeface.</p>, , HTML Hyperlinks (Links), A hyperlink (or link) is a word, group of words, or image, that you can click on to jump to a new document or a new, section within the current document., When you move the cursor over a link in a Web page,, the arrow will turn into a little hand., Links are specified in HTML using the <a> tag., , This will produce following result:, , The <a> tag can be used in two ways:, , The following word uses a big typeface., , 1 To create a link to another document, by using the, href attribute, , Smaller Text - The <small> Element:, The content of the <small> element is displayed one font, size smaller than the rest of the text surrounding it., <p>The following word uses a <small>small</, small> typeface.</p>, , 2 To create a bookmark inside a document, by using, the name attribute, The HTML code for a link is simple. It looks like this:, <a href="url">Link text</a>, , This will produce following result:, , The href attribute specifies the destination of a link., , The following word uses a small typeface., , <a href="http://www.yahoo.com/">Visit yahoo</a>, , Styling HTML with CSS, , which will display like this: Visit yahoo.com, , CSS was introduced together with HTML 4, to provide a, better way to style HTML elements., , Clicking on this hyperlink will send the user to Yahoo, homepage., , CSS can be added to HTML in the following ways:, , The "Link text" doesn't have to be text. It can be an image, or any other HTML element., , •, , Inline - using the style attribute in HTML elements, , •, , Internal - using the <style> element in the <head>, section, , •, , External - using an external CSS file, , <html>, <body style="background-color:PowderBlue;">, <h1>Look! Styles and colors</h1>, <p style="font-family:verdana;color:red;">, This text is in Verdana and red</p>, <p style="font-family:times;color:green;">, This text is in Times and green</p>, <p style="font-size:30px;">This text is 30 pixels high</, p>, </body>, , HTML Links - The target Attribute, The target attribute specifies where to open the linked, document., The example below will open the linked document in a, new browser window or a new tab:, Example, <a href="http://www.yahoo.com/" target="_blank">Visit, yahoo !</a>, <html>, <body>, <a href="http://www.yahoo.com" target="_blank">Visit, yahoo.com!</a>, , </html>, , <p>If you set the target attribute to "_blank", the link will, open in a new browser window/tab.</p>, , Result:, , </body>, , Look! Styles and colors, , </html>, , This text is in Verdana and red, This text is in Times and green, This text is 30 pixels high, 226, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 243 : Result, , <img src="boat.gif" alt="Big Boat" />, , Visit yahoo.com!, , The alt attribute provides alternative information for an image, if a user for some reason cannot view it (because of slow, connection, an error in the src attribute, or if the user uses, a screen reader)., , If you set the target attribute to "_blank", the link will open, in a new browser window/tab., HTML Images - The <img> Tag and the Src Attribute, In HTML, images are defined with the <img> tag., The <img> tag is empty, which means that it contains, attributes only, and has no closing tag., To display an image on a page, you need to use the src, attribute. Src stands for "source". The value of the src, attribute is the URL of the image you want to display., Syntax for defining an image:, <img src="url" alt="some_text"/>, The URL points to the location where the image is stored., An image named "bamboo. gif", located in the "images", directory on "www.w3schools.com" has the URL: http://, www.backgroundlabs.com/index.php?search=bamboo., The browser displays the image where the <img> tag, occurs in the document. If you put an image tag between, two paragraphs, the browser shows the first paragraph,, then the image, and then the second paragraph., HTML Images - The Alt Attribute, The required alt attribute specifies an alternate text for an, image, if the image cannot be displayed., The value of the alt attribute is an author-defined text:, , HTML Images - Set Height and Width of an Image, The height and width attributes are used to specify the, height and width of an image., The attribute values are specified in pixels by default:, <img src="rose.jpg" alt="Rose" width="304" height="228", />, Note: It is a good practice to specify both the height and, width attributes for an image. If these attributes are set,, the space required for the image is reserved when the, page is loaded. However, without these attributes, the, browser does not know the size of the image. The effect, will be that the page layout will change during loading, (while the images load)., If an HTML file contains ten images - eleven files are, required to display the page right. Loading images takes, time, so my best advice is: Use images carefully., When a web page is loaded, it is the browser, at that, moment, that actually gets the image from a web server, and inserts it into the page. (Fig 12) Therefore, make sure, that the images actually stay in the same spot in relation, to the web page, otherwise your visitors will get a broken, link icon. The broken link icon is shown if the browser, cannot find the image., , Fig 12, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 227
Page 244 : <html>, , All major browsers display the text in the <th> element as, bold and centered., , <body>, , <table border="1">, , <h2>Friendship Card</h2>, <img border="0" src="/images/Rose.jpg" alt="Rose", width="304" height="228" />, , <tr>, <th>Header 1</th>, , </body>, , <th>Header 2</th>, , </html>, , </tr>, , HTML Tables, , <tr>, , Tables are defined with the <table> tag., , <td>row 1, cell 1</td>, , A table is divided into rows (with the <tr> tag), and each, row is divided into data cells (with the <td> tag). td stands, for "table data," and holds the content of a data cell. A, <td> tag can contain text, links, images, lists, forms, other, tables, etc., , <td>row 1, cell 2</td>, , Table Example, , </tr>, <tr>, <td>row 2, cell 1</td>, <td>row 2, cell 2</td>, , <table border="1">, , </tr>, , <tr>, , </table>, , <td>row 1, cell 1</td>, , How the HTML code above looks in your browser:, , <td>row 1, cell 2</td>, </tr>, <tr>, <td>row 2, cell 1</td>, , Header 1, , Header 2, , row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , <td>row 2, cell 2</td>, , HTML Unordered Lists, , </tr>, , An unordered list starts with the <ul> tag. Each list item, starts with the <li> tag., , </table>, How the HTML code above looks in a browser:, row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , HTML Tables and the Border Attribute, If you do not specify a border attribute, the table will be, displayed without borders. Sometimes this can be useful,, but most of the time, we want the borders to show., , The list items are marked with bullets (typically small black, circles)., <ul>, <li>Coffee</li>, <li>Milk</li>, </ul>, How the HTML code above looks in a browser:, , To display a table with borders, specify the border attribute:, , •, , Coffee, , <table border="1">, , •, , Milk, , <tr>, , HTML Ordered Lists, , <td>Row 1, cell 1</td>, , An ordered list starts with the <ol> tag. Each list item, starts with the <li> tag., , <td>Row 1, cell 2</td>, , The list items are marked with numbers., , </tr>, , <ol>, , </table>, , <li>Coffee</li>, , HTML Table Headers, Header information in a table are defined with the <th>, tag., , <li>Milk</li>, </ol>, How the HTML code above looks in a browser:, 1 Coffee, , 228, , 2 Milk, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 245 : HTML Definition Lists, A definition list is a list of items, with a description of each, item., , When used together with CSS, the <div> element can be, used to set style attributes to large blocks of content., , The <dl> tag is used in conjunction with <dt> (defines the, item in the list) and <dd> (describes the item in the list):, , Another common use of the <div> element, is for document layout. It replaces the "old way" of defining layout, using tables. Using tables is not the correct use of the, <table> element. The purpose of the <table> element is, to display tabular data., , <dl>, , The HTML <span> Element, , <dt>Coffee</dt>, , The HTML <span> element is an inline element that can, be used as a container for text., , The <dl> tag defines a definition list., , <dd>- black hot drink</dd>, <dt>Milk</dt>, <dd>- white cold drink</dd>, </dl>, How the HTML code above looks in a browser:, Coffee - black hot drink, Milk- white cold drink, Note : Inside a list item you can put text, line, breaks, images, links, other lists, etc., , The <span> element has no special meaning., When used together with CSS, the <span> element can, be used to set style attributes to parts of the text., HTML Grouping Tags, Tag, , Description, , <div>, , Defines a div, , <span>, , Defines a span, , HTML Layout, Website Layouts, , HTML List Tags, Tag, , Description, , <ol>, , Defines an ordered list, , <ul>, , Defines an unordered list, , <li>, , Defines a list item, , <dl>, , Defines a definition list, , <dt>, , Defines an item in a definition list, , <dd>, , Defines a description of an item in a, definition list, , HTML elements can be grouped together with <div> and, <span>, , Most websites have put their content in multiple columns, (formatted like a magazine or newspaper)., Multiple columns are created by using <div> or <table>, elements. CSS are used to position elements, or to create backgrounds or colorful look for the pages., HTML Layouts - Using <div> Elements, The div element is a block level element used for grouping, HTML elements., The following example uses five div elements to create a, multiple column layout, creating the same result as in the, previous example:, Example, , HTML Block Elements, , <div>, , Most HTML elements are defined as block level elements, or as inline elements., , <!DOCTYPE html>, , Block level elements normally start (and end) with a new, line when displayed in a browser., , <body>, , Examples: <h1>, <p>, <ul>, <table>, HTML Inline Elements, Inline elements are normally displayed without starting a, new line., Examples: <b>, <td>, <a>, <img>, The HTML <div> Element, The HTML <div> element is a block level element that can, be used as a container for grouping other HTML elements., The <div> element has no special meaning. Except that,, because it is a block level element, the browser will display a line break before and after it., , <html>, <div id="container" style="width:500px">, <div id="header" style="background-color:#FFA500;">, <h1 style="margin-bottom:0;">Main Title of Web Page</, h1></div>, <divid="menu"style="backgroundcolor:#FFD700;height:200px;width:100px;float:left;">, <b>Menu</b><br />, HTML<br />, CSS<br />, JavaScript</div>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 229
Page 246 : <div, id="content", style="backgroundcolor:#EEEEEE;height:200px;width:400px;float:left;">, Content goes here</div>, <div, id="footer", style="backgroundcolor:#FFA500;clear:both;text-align:center;">, , </div>, </div>, </body>, </html>, Result (Fig 13), , Fig 13, , HTML Forms, , First name: <input type="text" name="firstname" /><br />, , HTML forms are used to pass data to a server., , Last name: <input type="text" name="lastname" />, , A form can contain input elements like text fields,, checkboxes, radio-buttons, submit buttons and more. A, form can also contain select lists, textarea, fieldset, legend, and label elements., , </form>, , The <form> tag is used to create an HTML form:, , Last name:, , <form>., , How the HTML code above looks in a browser:, First name:, , Note: The form itself is not visible. Also note, that the default width of a text field is 20, characters., , input elements., </form>, HTML Forms - The Input Element, , Password Field, , The most important form element is the input element., , <input type="password" /> defines a password field:, , The input element is used to select user information., , <form>, , An input element can vary in many ways, depending on, the type attribute. An input element can be of type text, field, checkbox, password, radio button, submit button,, and more., , Password: <input type="password" name="pwd" />, , The most used input types are described below., , Password:, , Text Fields, <input type="text" /> defines a one-line input field that a, user can enter text into:, , </form>, How the HTML code above looks in a browser:, , Note: The characters in a password field are, mased (shown as asterisks or circles), , <form>, , 230, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Radio Buttons, <input type="radio" /> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of, choices:, <form>, , If you type some characters in the text field above, and, click the "Submit" button, the browser will send your input, to a page called "html_form_action.asp". The page will, show you the received input., HTML Iframes, , <input type="radio" name="sex" value="male" /> Male<br/>, <input type="radio" name="sex" value="female" /> Female, </form>, How the HTML code above looks in a browser:, , Syntax for adding an iframe:, <iframe src="URL"></iframe>, The URL points to the location of the separate page., , Male, , Iframe - Set Height and Width, , Female, , The height and width attributes are used to specify the, height and width of the iframe., , Checkboxes, <input type="checkbox" /> defines a checkbox., Checkboxes let a user select ONE or MORE options of a, limited number of choices., <form>, <input type="checkbox" name="vehicle" value="Bike" />, I have a bike<br />, <input type="checkbox" name="vehicle" value="Car" /> I, have a car, , The attribute values are specified in pixels by default, but, they can also be in percent (like "80%")., Example, <!DOCTYPE html>, <html>, <body>, <iframe src="demo_iframe.htm", height="200"></iframe>, , width="200", , </body>, , </form>, How the HTML code above looks in a browser:, , </html>, It will appear as shown in Fig 14., , I have a bike, , Iframe - Remove the Border, , I have a car, , The frameborder attribute specifies whether or not to display, a border around the iframe., , Submit Button, <input type="submit" /> defines a submit button., A submit button is used to send form data to a server. The, data is sent to the page specified in the form's action, attribute. The file defined in the action attribute usually, does something with the received input:, <form name="input" action="html_form_action.asp", method="get">, Username: <input type="text" name="user" />, <input type="submit" value="Submit" />, , Set the attribute value to "0" to remove the border:, Example, <iframe src="demo_iframe.htm" frameborder="0"></, iframe>, Use iframe as a Target for a Link, An iframe can be used as the target frame for a link., The target attribute of a link must refer to the name attribute, of the iframe:, , </form>, How the HTML code above looks in a browser:, Username:, , Submit, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 231
Page 248 : Fig 14, , Example, , HTML Colour, , <iframe src="demo_iframe.htm" name="iframe_a"></, iframe>, < p > < a h r e f = " h t t p : / / w w w. y a h o o . c o m ", target="iframe_a">yahoo.com</a></p>, HTML iframe Tag, , Color Values, HTML colors are defined using a hexadecimal notation, (HEX) for the combination of Red, Green, and Blue color, values (RGB)., The lowest value that can be given to one of the light sources, is 0 (in HEX: 00). The highest value is 255 (in HEX: FF)., , Tag, , Description, , HEX values are specified as 3 pairs of two-digit numbers,, starting with a # sign., , <iframe>, , Defines an inline sub window (frame), , Color Values (Fig 15), , Fig 15, , Color, , Color HEX, , Color RGB, , #000000, , rgb(0,0,0), , #FF0000, , rgb(255,0,0), , #00FF00, , rgb(0,255,0), , #0000FF, , rgb(0,0,255), , #FFFF00, , rgb(255,255,0), , #00FFFF, , rgb(0,255,255), , #FF00FF, , rgb(255,0,255), , #C0C0C0, , rgb(192,192,192), , #FFFFFF, , rgb(255,255,255), , <!DOCTYPE html>, , Color set by using hex value, , <html>, , </p>, , <body>, , <p style="background-color:rgb(255,255,0)">, , <p style="background-color:#FFFF00">, , Color set by using rgb value, , 232, , </p>, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 249 : <p style="background-color:yellow">, Color set by using color name, </p>, </body>, , <noscript>Sorry, your browser does not support, JavaScript!</noscript>, <p>A browser without support for JavaScript will show the, text in the noscript element.</p>, </body>, , </html>, , </html>, , Result, Color set by using hex value, Color set by using rgb value, Color set by using color name, DHTML, The HTML script Element, The <script> tag is used to define a client-side script,, such as a JavaScript., The script element either contains scripting statements, or it points to an external script file through the src attribute., The required type attribute specifies the MIME type of the, script., Common uses for JavaScript are image manipulation, form, validation, and dynamic changes of content., The script below writes Hello World! to the HTML output:, Example, <script type="text/javascript">, document.write("Hello World!"), </script>, The HTML noscript Element, The <noscript> tag is used to provide an alternate content, for users that have disabled scripts in their browser or, have a browser that doesn't support client-side scripting., The noscript element can contain all the elements that, you can find inside the body element of a normal HTML, page., The content inside the noscript element will only be, displayed if scripts are not supported, or are disabled in, the user's browser:, Example, , Result, Hello World!, A browser without support for JavaScript will show the text, in the noscript element., HTML Script Tags, Tag, , Description, , <script>, , Defines a client-side script, , <noscript>, , Defines an alternate content for users, that do not support client-side scripts, , HTML Entities, Some characters are reserved in HTML., It is not possible to use the less than (<) or greater than, (>) signs in your text, because the browser will mix them, with tags., To actually display reserved characters, we must use, character entities in the HTML source code., A character entity looks like this:, &entity_name;, OR, &#entity_number;, Non-breaking Space, A common character entity used in HTML is the nonbreaking space ( )., Browsers will always truncate spaces in HTML pages. If, you write 10 spaces in your text, the browser will remove, 9 of them, before displaying the page. To add spaces to, your text, you can use the character entity., HTML Useful Character Entities, , <!DOCTYPE html>, , Note: Entity names are case sensitive!, , <html>, <body>, <script type="text/javascript">, , HTML Uniform Resource Locators, , document.write("Hello World!"), , A URL is another word for a web address., , </script>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 233
Page 250 : Result, , URL - Uniform Resource Locator, , Entity, Name, , Entity, Number, , non-breaking, space, , , ,  , , When you click on a link in an HTML page, an underlying, <a> tag points to an address on the world wide web., , <, , less than, , <, , <, , A Uniform Resource Locator (URL) is used to address a, document (or other data) on the world wide web., , >, , greater than, , >, , >, , Explanation:, , &, , ampersand, , &, , &, , •, , Scheme - defines the type of Internet service. The, most common type is http, , ¢, , cent, , ¢, , ¢, , •, , £, , pound, , £, , £, , Host - defines the domain host (the default host for, http is www), , ¥, , yen, , ¥, , ¥, , •, , Domain - defines the Internet domain name, like, w3schools.com, , •, , euro, , €, , €, , •, , §, , section, , §, , §, , Port - defines the port number at the host (the default, port number for http is 80), , ©, , copyright, , ©, , ©, , •, , ®, , registered, trademark, , ®, , ®, , Path - defines a path at the server (If omitted, the, document must be stored at the root directory of the, web site), , •, , Filename - defines the name of a document/resource, , trademark, , ™, , ™, , Description, , ™, , Common URL Schemes, , A URL can be composed of words, such as, "w3schools.com", or an Internet Protocol (IP) address:, 192.68.20.50. Most people enter the name of the website, when surfing, because names are easier to remember than, numbers., Scheme, , The table below lists some common schemes:, , Short for...., , Which pages will the scheme be used for..., , http, , HyperText Transfer Protocol, , Common web pages starts with http://. Not encrypted, , https, , Secure HyperText Transfer, Protocol, , Secure web pages. All information exchanged are encrypted, , ftp, , File Transfer Protocol, , For downloading or uploading files to a website. Useful for, domain maintenance, , file, , A file on your computer, , URL Encoding, , XML Structure, , URLs can only be sent over the Internet using the ASCII, character-set., , The XML structure including the document parts, the, prologue, and provides a simple XML example document., , Since URLs often contain characters outside the ASCII, set, the URL has to be converted into a valid ASCII format., , Document Parts, , URL encoding replaces non ASCII characters with a "%", followed by two hexadecimal digits., , •, , Prolog, , •, , Document Element (root element), , URLs cannot contain spaces. URL encoding normally, replaces a space with a + sign., 234, , The Prologue, The prologue, equivalent to the header in HTML, may, include the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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•, , •, , •, , An XML declaration (optional) such as:, , TYPES OF Web Hosting, , <?xml version="1.0"?>, , There are four types of Web hosting, , A DTD or reference to one (optional). An example, reference to an external DTD file:, , 1 Free hosting, 2 Dedicated hosting, , <!DOCTYPE LANGLIST SYSTEM "langlist.dtd">, , 3 Shared (Virtual) hosting, , Processing instructions - An example processing, instruction that causes style to be determined by a, style sheet:, , 4 Collocated Hosting, , <?xml-stylesheettype="text/css", href="xmlstyle.css"?>, An XML Example, Therefore a complete well formed XML document may look, like:, <?xml version="1.0"?>, <LAND>, <FOREST>, <TREE>Oak</TREE>, <TREE>Pine</TREE>, <TREE>Maple</TREE>, </FOREST>, <MEADOW>, <GRASS>Bluegrass</GRASS>, <GRASS>Fescue</GRASS>, , Free hosting, Free web hosting is best suited for small sites with low, traffic, like personal sites. It is not recommended for high, traffic or for real business. Technical support is often, limited, and technical options are few., Dedicated Hosting, With dedicated hosting, your web site is hosted on a, dedicated server. Dedicated hosting is the most expensive, option. This option is best suited for large web sites with, high traffic, and web sites that use special software., Dedicated hosting to be very powerful and secure, with, almost unlimited software solutions., Shared (Virtual) Hosting, Shared hosting is very cost effective., With shared hosting, your web site gets its own domain, name, and is hosted on a powerful server along with maybe, 100 other web sites. Shared solutions often offer multiple, software solutions like e-mail, database, and different editing, options. Technical support tends to be good., Collocated Hosting, , Result, , Collocation means "co-location". Collocated hosting lets, place own web server on the premises (locations) of a, service provider. This is pretty much the same as running, own server in your own office, only that it is located at a, place better designed for it. Most likely an ISP will have, dedicated resources like high-security against fire and, vandalism, regulated backup power, dedicated Internet, connections and more., , Oak Pine Maple Bluegrass Fescue Rye, , Web Server, , <GRASS>Rye</GRASS>, </MEADOW>, </LAND>, The LAND element, above, is the root element., , Web Elements, A web page, as an information set, can contain numerous, types of information, which is able to be seen, heard or, interact by the End-user, Web Hosting, A web hosting service is a type of Internet hosting service, that allows individuals and organizations to make their, Website accessible via the World Wide Web. Web hosts, are companies that provide space on a Server (computing), owned or leased for use by clients, as well as providing, Internet connectivity, typically in a data centre. Web hosts, can also provide data centre space and connectivity to, the Internet for other servers located in their data centre,, called Collocation., , A Web server is a program that, using the client server, model and the World Wide Web's Hypertext Transfer, Protocol ( HTTP), serves the files that form Web pages to, Web users (whose computers contain HTTP clients that, forward their requests). Every computer on the Internet, that contains a Web site must have a Web server program., Two leading Web servers are Apache, the most widelyinstalled Web server, and Microsoft's Internet Information, Server (IIS). Other Web servers include Novell's Web Server, for users of its Netware operating system and IBM's family, of Lotus Domino servers, primarily for IBM's OS390 and, AS-400 customers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 235
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Web servers often come as part of a larger package of, Internet- and intranet-related programs for serving e-mail,, downloading requests for File Transfer Protocol (FTP) files,, and building and publishing Web pages. Considerations, in choosing a Web server include how well it works with, the operating system and other servers, its ability to handle, server-side programming, security characteristics, and, publishing, search engine, and site building tools that may, come with it., , Application Server, Also called an appserver, and application server (Fig 16), is a program that handles all application operations, between users and an organization's backend business, applications or database. An application server is typically, used for complex transaction-based applications. To, support high-end needs, an application server has to have, built-in redundant, monitor for high-availability, highperformance distributed application services and support, for complex database access., , Fig 16, , Database Server, Database server (Fig 17) is the term used to refer to the, back-end system of a database application using client-, , 236, , server architecture. The back-end, sometimes called a, database server, performs tasks such as data analysis,, storage, data manipulation, archiving, and other non-user, specific tasks., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Designing Static WebPages, , Related Theory for Exercise 1.12.93, , Introduction to CMS and web authoring tools, Objectives: At the end of this lesson you shall be able to, • explain the meaning of content management System., • list some of the popular CMSes., • explain the use and main features of kompozer web authoring tool., Definition of CMS:, , •, , CMS Stands for "Content Management System." A CMS, is a software tool that allows you to create, edit, and publish content., , Weebly - a web-based platform for building simple personal and business websites, , •, , Wix - a collection of web publishing tools for creating a, highly customizable website, , Description of CMS:, The goal of a CMS is to provide an intuitive user interface, for building and modifying webpage content. Each CMS, also provides a web publishing tool that allows one or more, users to publish updates live on the Web. The editing component is called the content management application, (CMA), while the publishing tool is called the content delivery application (CDA). These two components are integrated together in a CMS to streamline the web development process., In terms of web publishing, content can be simple text,, photos, music, video, documents, or just about anything, you can think of. While early CMS software was used to, manage documents and local computer files, most CMS, systems are now designed exclusively to manage content on the Web. A major advantage of using a CMS is, that it requires almost no technical skill or knowledge to, manage., Content management systems are available as installable, applications and web-based user interfaces. The use of a, web interfacesimplifies the website updating process., Additionally, most web-based CMSes are updated automatically, ensuring all users have the latest tools to manage their content., A major advantage of using a CMS is that it requires almost no technical skill or knowledge to manage. Since, the CMS manages all your content, you don't have to., There are several web-based CMS tools available today., The following are some of the most popular ones:, •, , WordPress - free web software designed for creating, template-based websites or blogs, , •, , Blogger - Google's blogging tool designed specifically, for maintaining a blog, , •, , Joomla - a flexible web publishing tool that supports, custom databases and extensions, , •, , Drupal - an open source platform often used for developing community-based sites, , Introduction to WSYIWYG web authoring tools, WYSIWYG stands for "What You See Is What You Get"., In such editors you edit not directly the source code of, your documents, but its presentation as it will appear in, the final document. So instead of writing blocks of code, manually (as you e.g. would do it in Word or Notepad),, you manipulate with design components using an editor, window. This means that you view something very similar, to the final result while the document or image is being, created., There are many easy-to-use WYSIWYG programs having, all the tools needed to create a complex and fully functional websites, even by beginners. These sites even have, options to work with HTML code be it design or editing.It, is easier to create a Web site with an HTML editor, as, software developers continue to add tools that let you develop advanced features with style.Many WSYIWYG web, authoring tools offer advanced features to integrate Dynamic HTML or many other features into a site with an, elegant and consistent design., Introduction to Kompozer, KompoZer is a complete Web Authoring System that combines web file management and easy-to-use, WYSIWYGweb page editing capabilities found in Microsoft, FrontPage, Adobe DreamWeaver and other high end programs. With kompozer you can create web pages and, manage a website with no technical expertise or knowledge of HTML., A useful feature of Kompozer is that you can use it to, publish your web pages to a web hosting server. You just, need to know your FTP account username and password, as well as the site URL and Kompozer will log in and, place your web pages on the server., KompoZer's File Menu contains menu items for all major, operations possible while using it. KompoZer's tool bar, user interface consists of:, , Copyright @ NIMI Not to be Republished, , 237
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Composition Toolbar, , •, , Format Toolbar, , •, , Tab Browser Toolbar, , •, , Edit Mode Toolbar, , •, , Status Toolbar, , Edit Mode Toolbar(Refer Fig.4), The Edit Mode Toolbar indicates the viewing mode which, is presently active for the current document. Available viewing modes are the Normal view, HTML Tags view, HTML, source view and the Preview mode. You can easily change, your viewing mode by simply clicking any of the other, three with the mouse., , Composition Toolbar, , copa 1308201, , The Composition Toolbar consists of buttons for the most, used major operations. Below is the a snapshot of the, default Composition Toolbar with text below each button, indicating the respective button's function. (Refer Fig.1), Fig 1, , Format Toolbar(Refer Fig.2), , copa 1308204, , Status Toolbar(Refer Fig.5), KompoZer's status bar shows the position of the cursor, with respect to the HTML tag hierarchy. You can easily, edit/assign the properties of any particular tag in the status bar just by right clicking and choosing the desired, option. Simple left-click of the mouse on a tag in status, bar selects the text surrounded by that tag., Fig 5, , copa 1308202, , The Format Toolbar is a very useful tool while editing web, pages with KompoZer. With the Format Toolbar you can, apply paragraph format, choose a font, change foreground, or background colour, increase or decrease size, and, emphasize a block of text. You can also create ordered or, unordered lists and justify a block of text to left, right or, centre. To know which button does what just hover your, mouse over the button and a tool tip will appear indicating, the function of the button., , Fig 4, , Fig 2, , Tab Browser Toolbar(Refer Fig.3), KompoZer allows you to simultaneously edit multiple web, documents using different tabs for each opened document., Having multiple tabs gives a cleaner look to your desktop, as it is not cluttered when multiple windows are used for, each document. As a visual indicator a "red floppy icon", icon appears for pages which have been edited but not, saved yet., Fig 3, copa 1308203, , 238, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.93, , Copyright @ NIMI Not to be Republished, , copa 1308205, , •
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Page 257 : Sector, , : IT & ITES, , Duration : 1 - Year, Trade, , Copyright, , : Computer Operator and Programming Assistant 1st Semester - Trade Theory, NSQF level 4, , 2018 National Instructional Media Institute, Chennai, , First Edition :, Second Edition :, , September 2018, December 2018, , Copies : 1,000, Copies :1,000, , Rs. 255 /-, , All rights reserved., No part of this publication can be reproduced or transmitted in any form or by any means, electronic or mechanical, including, photocopy, recording or any information storage and retrieval system, without permission in writing from the National, Instructional Media Institute, Chennai., , Published by:, NATIONAL INSTRUCTIONAL MEDIA INSTITUTE, P. B. No.3142, CTI Campus, Guindy Industrial Estate,, Guindy, Chennai - 600 032., Phone : 044 - 2250 0248, 2250 0657, 2250 2421, Fax : 91 - 44 - 2250 0791, email :
[email protected],
[email protected], Website: www.nimi.gov.in, (ii), , Copyright @ NIMI Not to be Republished
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FOREWORD, , The Government of India has set an ambitious target of imparting skills to 30 crores people, one out of every, four Indians, by 2020 to help them secure jobs as part of the National Skills Development Policy. Industrial, Training Institutes (ITIs) play a vital role in this process especially in terms of providing skilled manpower., Keeping this in mind, and for providing the current industry relevant skill training to Trainees, ITI syllabus, has been recently updated with the help of Mentor Councils comprising various stakeholder's viz. Industries,, Entrepreneurs, Academicians and representatives from ITIs., The National Instructional Media Institute (NIMI), Chennai, has now come up with instructional material to, suit the revised curriculum for Computer Operator and Programming Assistant Trade Theory 1st, Semester in IT & ITES Sector . The NSQF Level - 4 Trade Theory will help the trainees to get an international, equivalency standard where their skill proficiency and competency will be duly recognized across the globe, and this will also increase the scope of recognition of prior learning. NSQF Level - 4 trainees will also get, the opportunities to promote life long learning and skill development. I have no doubt that with NSQF Level, - 4 the trainers and trainees of ITIs, and all stakeholders will derive maximum benefits from these IMPs and, that NIMI's effort will go a long way in improving the quality of Vocational training in the country., The Executive Director & Staff of NIMI and members of Media Development Committee deserve appreciation, for their contribution in bringing out this publication., Jai Hind, , RAJESH AGGARWAL, , Director General/ Addl. Secretary, Ministry of Skill Development & Entrepreneurship,, Government of India., , New Delhi - 110 001, , (iii), , Copyright @ NIMI Not to be Republished
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PREFACE, The National Instructional Media Institute (NIMI) was established in 1986 at Chennai by then Directorate, General of Employment and Training (D.G.E & T), Ministry of Labour and Employment, (now under Directorate, General of Training, Ministry of Skill Development and Entrepreneurship) Government of India, with technical, assistance from the Govt. of the Federal Republic of Germany. The prime objective of this institute is to, develop and provide instructional materials for various trades as per the prescribed syllabi under the Craftsman, and Apprenticeship Training Schemes., The instructional materials are created keeping in mind, the main objective of Vocational Training under, NCVT/NAC in India, which is to help an individual to master skills to do a job. The instructional materials are, generated in the form of Instructional Media Packages (IMPs). An IMP consists of Theory book, Practical, book, Test and Assignment book, Instructor Guide, Audio Visual Aid (Wall charts and Transparencies) and, other support materials., The trade practical book consists of series of exercises to be completed by the trainees in the workshop., These exercises are designed to ensure that all the skills in the prescribed syllabus are covered. The trade, theory book provides related theoretical knowledge required to enable the trainee to do a job. The test and, assignments will enable the instructor to give assignments for the evaluation of the performance of a trainee., The wall charts and transparencies are unique, as they not only help the instructor to effectively present a, topic but also help him to assess the trainee's understanding. The instructor guide enables the instructor to, plan his schedule of instruction, plan the raw material requirements, day to day lessons and demonstrations., IMPs also deals with the complex skills required to be developed for effective team work. Necessary care, has also been taken to include important skill areas of allied trades as prescribed in the syllabus., The availability of a complete Instructional Media Package in an institute helps both the trainer and, management to impart effective training., The IMPs are the outcome of collective efforts of the staff members of NIMI and the members of the Media, Development Committees specially drawn from Public and Private sector industries, various training institutes, under the Directorate General of Training (DGT), Government and Private ITIs., NIMI would like to take this opportunity to convey sincere thanks to the Directors of Employment & Training, of various State Governments, Training Departments of Industries both in the Public and Private sectors,, Officers of DGT and DGT field institutes, proof readers, individual media developers and coordinators, but for, whose active support NIMI would not have been able to bring out this materials., , R. P. DHINGRA, EXECUTIVE DIRECTOR, , Chennai - 600 032, , (iv), , Copyright @ NIMI Not to be Republished
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INTRODUCTION, TRADE THEORY, The manual of trade theory consists of theorectical information for the First Semester couse of the COPATrade., The contents are sequenced accoring to the practical exercise contained in the manual on Trade practical., Attempt has been made to relate the theortical aspects with the skill covered in each exercise to the extent, possible. This co-relation is maintained to help the trainees to develop the perceptional capabilities for, performing the skills., The Trade Theory has to be taught and learnt along with the corresponding exercise contained in the manual, on trade practical. The indicating about the corresponding practical exercise are given in every sheet of this, manual., It will be preferable to teach/learn the trade theory connected to each exercise atleast one class before, performing the related skills in the system lab. The trade theory is to be treated as an integrated part of each, exercise., The material is not the purpose of self learning and should be considered as supplementary to class room, instruction., TRADE PRACTICAL, The trade practical manual is intented to be used in workshop . It consists of a series of practical exercies to, be completed by the trainees during the First Semester course of the COPA trade supplemented and, supported by instructions/ informations to assist in performing the exercises. These exercises are designed, to ensure that all the skills in the prescribed syllabus are covered., The manual is divided into twelve modules to maintain completancy of leaning process in a stipulated time, basis., The skill training in the computer lab is planned through a series of practical exercises centred around some, practical project. However, there are few instance where the individual exercise does not form a part of project., While developing the practical manual a sincere effort was made to prepare each exercise which will be easy, to understand and carry out even by below average traninee. However the development team accept that there, if a scope for further improvement. NIMI, looks forward to the suggestions from the experienced training faculty, for improving the manual., , (vi), , Copyright @ NIMI Not to be Republished
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CONTENTS, Lesson No., , Title of the Lesson, , Page No., , Module 1: Safe working practices, 1.1.01 &1.1.02, , Electrical safety, , 1, , 1.1.03 & 1.1.04, , Safety practices, fire extinguishers, , 2, , Module 2: Introduction to computer components, 1.2.05, , Introduction to computers, , 7, , 1.2.06, , Introduction to CPU architecture and mother board, , 17, , Module 3: Windows operating system, 1.3.07 -1.3.11, , Windows operating system, , 25, , 1.3.12, , Handling printers, , 33, , Module 4: Computer basics and software installation, 1.4.13, , CMOS setup and windows installation, , 36, , 1.4.14 & 1.4.15, , CMOS setup and windows installation, , 38, , 1.4.16, , Troubleshooting computer, , 42, , 1.4.17, , Application Softwares, , 47, , 1.4.18 & 1.4.19, , Bluetooth devices, , 49, , 1.4.20, , DVDs, CDs and burning DVDs, , 51, , Module 5: Dos & LInux operating systems, 1.5.21, , Comand line interface with DOS, , 53, , 1.5.22, , Methods to display the contents of a text file, , 56, , 1.5.23, , Introduction to Linux operating system, , 60, , 1.5.24 - 1.5.26, , Handling commands and various editors, , 63, , 1.5.27 - 1.5.28, , Managing files and directories, , 80, , Module 6: Word Processing Software, 1.6.29, , MS word 2010 Theory, , 113, , 1.6.30 - 1.6.37, , Creating a file, save and other options, , 117, , 1.6.38, , Typing practice using open source typing tutor tools, , 123, , (vii), , Copyright @ NIMI Not to be Republished
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Lesson No., , Title of the Lesson, , Page No., , Module 7: Spread sheet Application, 1.7.39 - 1.7.41, , Introduction to MS - Excel 2010, , 124, , 1.7.42 - 1.7.46, , Functions and formulas in MS- Excel 2010, , 133, , 1.7.47 - 1.7.48, , Data validations and Table management in Ms Excel 2010, , 138, , Module 8: Image Editing, presentations, 1.8.49 - 1.8.57, , Image editing, presentations, , 145, , Module 9: Database Management Systems, 1.9.58 - 1.9.61, , Concepts of data and Databases, , 152, , 1.9.62 - 1.9.66, , Forms, quires, and reports in access, , 163, , Module 10: Networking concepts, 1.10.67 - 1.10.69, , Concepts of network and internet, , 169, , 1.10.70, , Introduction to TCP/IP, , 188, , 1.10.71 & 1.10.72, , Transmission media and network components, , 190, , 1.10.73A, , Computer name and workgroup, , 197, , 1.10.73B, , Concept of proxy server, , 200, , 1.10.74, , Video conferencing, , 202, , 1.10.75, , Network security, , 203, , Module 11: Internet Concepts, 1.11.76 & 1.11.77, , E- mail, , 205, , 1.11.78, , Chatting,video chatting and using social network sites, , 209, , 1.11.79, , Explaining threats to computers connected to Internet & process, , 210, , 1.11.80 & 1.11.81, , Outlook Express & Google+, , 213, , Module 12: Designing Static Webpages, 1.12.82 - 1.12.92, , Web designing, , 214, , 1.12.93, , Introduction to CMS and web authoring tools, , 237, , (viii), , Copyright @ NIMI Not to be Republished
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LEARNING / ASSESSABLE OUTCOME, On completion of this book you shall be able to, • Install and setup operating system and related software in a, computer., • Create, format and edit document using word processing application software., • Create, edit and develop a workbook by using spreadsheet application software., • Create and customize slides for presentation., • Create and manage database file by using MS Access, • Install, setup/ configure, troubleshoot and secure computer network including Internet., • Develop static webpages using HTML., , (ix), , Copyright @ NIMI Not to be Republished
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SYLLABUS, First Semester, Week, No., 1., , Duration: Six Month, , Ref. Learning, Outcome, , •, , Apply safe working, practices, , • Install and setup, , operating system, and related software, in a computer., , Professional Skills, (Trade Practical), with Indicative hours, , Safe working practices, Safe working practices, • Scope of the COPA trade., 1. Visit COPA Lab. of the institutes and, locate the electrical connections with • Safety rules and safety signs., computer system setup (6 hrs), • Types and working of fire, 2. Identifying safety symbols and, extinguishers., hazard identification.(4 Hrs), Introduction to Computer, 3. Practice safe methods of fire fighting in, components, case of electrical fire. (4 hrs), • Introduction to computer, 4. Use of fire extinguishers. (4 Hrs), system. Concepts of hardward, Computer components, and Software., 5. Identify computer peripherals and, •, Function of motherboard, internal components of a disassembled, components and various, desktop computer. (6 Hrs), processors., 6. Assemble components of desktop, computer. (6 Hrs), • Various Input / Output devices, in use and their features., , 2., , • Install and setup, , Using Windows Operating System, 7. Practice on Windows interface, and navigating windows. (9 Hrs), 8. Practice on managing files and, folders using removable drives. (6 Hrs), 9. Customize the desktop settings, and manage user accounts. (6 Hrs), 10. View system properties and control, panel details. (6 Hrs), 11. Work with keyboard shortcut commands., (6 Hrs), 12. Print and scan document using different, commands.(3 Hrs), , 3., , • Install and setup, , Computer basics and Software, Installation, 13. View the BIOS settings and their, modifications. (3 Hrs), 14. Install Windows OS (5 Hrs), 15. Format Hard Disk and create, partition (3 Hrs), 16. Identify and rectify common, hardware and software issues, during OS installation. (4 Hrs), 17. Install necessary application, software for Windows i.e. Office, Package, PDF Reader, Media, Player etc. (5 Hrs), 18. Configure Bluetooth and wi-fi, settings. (3 Hrs), 19. Install Drivers for printer, scanner,, webcam and DVD etc. (4 Hrs), 20. Burn data, video and audio files on, CD/DVD using application, software. (3 Hrs), , operating system, and related software, in a computer., , operating system and, and related software, in a computer., , Professional Knowledge, (Trade Theory), , COPA 1st semester, , Introduction Windows, Operating System, • Introduction to operating, System, • Main features of Windows, OS, • Concept of various shortcut, commands., , Computer basics and Software, Installation, • Introduction to the booting, process., • Introduction to various, types of memories and their, features., • Basic Hardware and, software issues and their, solutions., • Usage of Application, software and Antivirus., , Copyright @ NIMI Not to be Republished
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• Install and, , DOS Command Line Interface & Linux, Operating Systems, 21. Use basic DOS commands for directory listing (10 hrs), 22. Manage files and folders using DOS commands (6 hrs), 23. Install Linux operating system.(6 Hrs), 24. Install necessary application software for Linux i.e., Office Package, PDF Reader, MediaPlayer etc. (6 Hrs), 25. Use Basic Linux commands for directory listing, file, and folder management, password etc. (10Hrs), 26. Use the Linux GUI for file and folder management,, exploring the system etc. (10 Hrs), 27. Customize desktop settings and manage user, accounts in Linux. (6 Hrs), 28. View system properties and manage system setting, in Linux (6 Hrs), , 6-8, , Create, format, and edit, document using, word, processing, application, software., , Word Processing, Using Word Processing Software, 29. Open MS Word and familiarise with basic word Software, components. (3 Hrs), • Introduction to the various, 30. Practice creating, saving and renaming of word, applications in MS office., documents.(3 Hrs), • Introduction to Word, 31. Edit document using basic formatting tools. (8 Hrs), features,, 32. Practice Inserting and formatting tables and other, Office button, toolbars., objects. (12 Hrs), • Creating, saving and, 33. Work with Page layout settings and printing, formatting, documents. (6 Hrs), and printing documents, 34. Use templates, autocorrect tools, and record and, using Word., execute a macro. (6 Hrs), 35. Use Mail merge tool. Use conditional Mail Merge, • Working with objects,, macro, mail merge,, External Data Source. Practice Letters, Label &, templates and other tools, Envelop printing using Mail Merge (10 Hrs)., in Word., 36. Use Table of Context, Indexing, Hyperlink, Bookmark,, Comment, equation,symbols,citation, crossreference,, footnote, translate, synonyms, thesaurus, spell, check & grammer, compare etc. ( 6 Hrs ), 37. Practice Typing using open source tutor. (24 Hrs), 38. Practice of using shortcut keys and use Open Office, as word processor. (12 Hrs), , 9 - 11, , • Create,, , 4-5, , setup OS, and related, software in a, computer., , Introduction to DOS, Command, Line Interface & Linux, Operating, Systems, • Introduction to basic DOS, Internal and External, Commands., • Introduction to Open, Source Software., • Introduction to Linux, Operating System features,, structure,, files, and, processes., • Basic Linux commands., , Using Spread Sheet Application, Spread Sheet Application, 39. Open MS Excel and familiarise with basic application • Introduction to Excel, format,, components. (4 Hrs), edit and, features and Data Types., 40., Practice, create, save and format excel sheets. (9 Hrs), develop, • Cell referencing and, a workbook by 41. Use absolute and relative referencing, linking sheets,, linking, conditional formatting etc. (9 Hrs), using, Sheets., spreadsheet 42. Practice Excel functions of all major categories i.e. • Introduction to various, Financial, Logical, Text, date & time, Lookup, Math,, application, functions in all categories, Statistical etc. (12 Hrs), software., of Excel., 43. Use various data types in Excel, sorting, filtering and, • Concepts of sorting,, validating data. (8 Hrs), 44. Create and format various static and dynamic charts., filtering, (10 Hrs), and validating data., 45. Practice Importing & exporting excel data. (4 Hrs), • Analyzing data using, 46. Perform data analysis using “what if” tools and Pivot, charts, data tables, pivot, Table and record and execute a macro. (10 Hrs), tables, goal seek and, 47. Modify Excel page setup and printing and use open, scenarios., office as Spreadsheet application. (4 Hrs), 48. Execute simple projects using Excel & Word. (20 Hrs), , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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12 - 13, , Create and, customize, slides for, presentation., , 14 - 15, , Create and, manage, database, file by, using MS, Access., , 16 - 17, , Install,, setup/, configure,, troubleshoot, and secure, computer, network, including, Internet., , Image editing and creating, Presentations, 49. Use Windows Paint or image editing, software like Open Office Draw, GIMP,, IrfanView or a similar tool. (6 Hrs), 50. Perform Image editing using open, source applications. (12 Hrs), 51. Open power point presentation, and familiarise with basic, application components. (6 Hrs), 52. Create Slide shows, Insert picture, and theme. (6 Hrs), 53. Add new slide, format text, link with word, and excel documents. (5 Hrs), 54. Practice animating slide transitions and, objects. (4 Hrs), 55. Create slide shows by inserting audio &, video and sync with presentation. (6 Hrs), 56. Modify slide page setup and print, the slides. (3 Hrs), 57. Create a simple presentation, project using open office. (12 Hrs), Database Management with MS Access, 58. Create database and design a simple tables, in Access. (6 Hrs), 59. Practice enforcing integrity constraints and, modify properties of tables and fields. (6, Hrs), 60. Create relationships and join tables. (6 Hrs), 61. Create and format Forms. (6 Hrs), 62. Create simple queries with various criteria, and calculations. (12 Hrs), 63. Create Simple update, append, make table,, delete and crosstab queries. (9 Hrs), 64. Modify form design with controls, macros, and events. (6 Hrs), 65. Import and export data to/from Access and, create and format types of reports. (6 Hrs), 66. Compress and Encrypt databases. (3 Hrs), , Image editing, Presentations, • Introduction to Open Office., • Introduction to the, properties and editing of, images., • Introduction to different, formats of images and their, uses., • Introduction to Power Point, and its advantages., • Creating Slide Shows., • Fine tuning the, presentation and good, presentation technique., , Database Management Systems, • Concepts of Data and Databases., • Overview of popular databases,, RDBMS, OODB and NOSQL., • Rules for designing good tables., Integrity rules and constraints in, a table., • Relationships in tables., • Introduction to various types of, Queries and their uses., • Designing Access Reports and, Forms., • Introduction to macros, designer, objects controls, their properties, and behaviour., , Configuring and using Network, Networking Concepts, 67. View Network connections. (3 Hrs), • Introduction to Computer Networks,, 68. Connect a computer to a n/w and share, Necessity and Advantages., Devices i.e. Printers, files, folders and, • Client Server and peer to Peer, drives. (6 Hrs), networking concepts., 69. Work with various Network devices,, •, Concept of Proxy Server and proxy, connectors/cables. Create straight/cross, firewall server., cable and punch a UTP cable in the patch, • Concept of DHCP Server., socket and test the connectivity. (6 Hrs), 70. Practice IP Addressing and Subnet masking • Introduction to LAN, WAN and MAN., for IPV4/ IPV6 and pinging to test networks. • Network topologies. Network, (6 Hrs), components, viz. Modem, Hub,, 71. Configure Hub and Switch. (6 Hrs), Switch, Router,Bridge, Gateway etc., 72. Set up and configure wired and wireless, • Network Cables, Wirelessnetworks, LAN in a Computer Lab within at least three, and Blue Tooth technology., computers. Use patch panel & I/O Box for, •, Concept of ISO - OSI 7 Layer Model., wired LAN and installing & configuring, Internet connection in a single PC and in a • Overview of Network protocols, Viz.TCP/IP, FTP, Telnet etc., LAN. (12 Hrs), COPA1st semester, , Copyright @ NIMI Not to be Republished
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73. Setup a proxy server/DHCP Server with firewall.(9 Hrs), 74. Setup video conferencing using open source s/w(6 Hrs), 75. Use various tools (by open source /free) for network, troubleshooting, maintenance and security for both, Wired and Wireless(6 Hrs), 18, , • Concept of Logical and, , Physical Addresses,, Subnetting and Classes of, Networks., , Using Internet, Install,, Internet Concepts, 76. Browse the Internet for information (use at least 3 • Introduction to www,, setup/, popular browsers). (3 Hrs), configure,, Concept of Internet, Web, troubleshoot 77. Create and use e-mail for communication with, Browsers, internet servers, attachment, priority setting, address book. (3 Hrs), and secure, and search engines., 78. Communicate with text, video chatting and social, computer, •, Concepts of Domain naming, networking sites. (6 Hrs), network, Systems and E mail, 79. Use online dictionary, translation software, storage, including, communication., space, share files with e-mail links, download manager,, Internet., •, Introduction to video chatting, download & upload YouTube files, google map & earth, tools and Social Networking, etc. Update windows & other software. (6 Hrs), concepts., 80. Configure Outlook, mail service in mobile phones. Use, tools like Skype, Google+ etc. (6 Hrs), 81. Browser setting for Bookmark, cookies, favourites and, pop ups, default website, trusted site,restricted site,, content, history and advanced setup. (6 Hrs ), , Web Design Concepts, Designing Static Web Pages, 19-21 Develop, 82. Practice with basic HTML elements (e.g. head, title, • Concepts of Static and, static, body), tag and attributes. (3 Hrs), Dynamic Web pages., web pages, 83. Design simple web page with text, paragraph and line • Introduction to HTML and, using, break usingHTML tags. (5 Hrs), HTML., various tags in HTML., 84. Format text, change background colour and insert, • Concepts of different, pictures in web page. (6 Hrs), controls used in Web Pages., 85. Design simple web page with tables and lists. (6 Hrs), 86. Use marquees, hyperlinks and mailto link in designing • Concepts of CSS and, applying CSS to HTML., web pages.(6 Hrs), •, Introduction to open source, 87. Create frames, add style and design layout. (10 Hrs), CMS viz, Joomla, Word, 88. Insert text, check and combo box in web page. (6 Hrs), press etc. and Web, 89. Design web page using password field, submit button,, authoring tools viz., reset button and radio button etc. (6 Hrs), Kompozer, Front Page etc., 90. Design a web page adding flash file, audio and video, files. (10 Hrs), • Concept of good web page, 91. Design web page with forms and form controls using, designing techniques., HTML tags.(8 Hrs), 92. Create web page using Cascading Style Sheet (CSS)., (12 Hrs), 93. Use WYSIWYG (Kompozer) web design tools to, design and edit web pages with various styles. (12Hrs), 22-23 Industrial Visit/Project work, 1. Create a simple web site of at least 5 web pages which will include Images, tables, charts, lists and, hyperlink on any topic like Student Information System, Book Store, and Organisations etc., OR, 2. Setup and configure a LAN using at least 3 computers connected with wire and 3 computers connected, with wireless and secure it.), 24-25, 26, , Revision, Examination, , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.01 &1.1.02, , Electrical safety, Objective : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire., The severity of an electric shock will depend on the level of, current which passes through the body and the length of, time of contact. Do not delay, act at once. Make sure that, the electric current has been disconnected., , If the casualty is unconscious but is breathing, loosen the, clothing about the neck, chest and waist and place the, casualty in the recovery position.( Fig 3), , If the casualty is still in contact with the supply - break the, contact either by switching off the power, removing the plug, or wrenching the cable free. If not, stand on some insulating, material such as dry wood, rubber or plastic, or using, whatever is at hand to insulate yourself and break the, contact by pushing or pulling the person free. (Figs 1 & 2), If you remain un-insulated, do not touch the victim with your, bare hands until the circuit is made dead or person is, moved away from the equipment., , Keep a constant check on the breathing and pulse rate., Keep the casualty warm and comfortable. (Fig 4), Send for help., Do not give an unconscious person anything by, mouth., Do not leave an unconscious person unattended., If the casualty is not breathing - Act at once - don’t waste, , If the victim is aloft, measures must be taken to prevent him, from falling or atleast make him fall safe., Electric burns on the victim may not cover a big area but, may be deep seated. All you can do is to cover the area, with a clean, sterile dressing and treat for shock. Get, expert help as quickly as possible., , Copyright @ NIMI Not to be Republished, , 1
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.03 & 1.1.04, , Safety practice - fire extinguishers, Objectives : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire, • distinguish the different types of fire extinguishers, • determine the correct type of fire extinguisher to be used based on the class of fire, • describe the general procedure to be adopted in the event of a fire., Fire is the burning of combustible material. A fire in an, unwanted place and on an unwanted occasion and in an, uncontrollable quantity can cause damage or destroy, property and materials. It might injure people, and, sometimes cause loss of life as well. Hence, every effort, must be made to prevent fire. When a fire outbreak is, discovered, it must be controlled and extinguished by, immediate corrective action., Is it possible to prevent fire? Yes, fire can be prevented by, eliminating anyone of the three factors that causes fire., The following are the three factors that must be present in, combination for a fire to continue to burn. (Fig 1), , Accumulation of combustible refuse (cotton waste soaked, with oil, scrap wood, paper, etc.) in odd corners are a fire, risk. Refuse should be removed to collection points., The cause of fire in electrical equipment is misuse or, neglect. Loose connections, wrongly rated fuses, overloaded, circuits cause overheating which may in turn lead to a fire., Damage to insulation between conductors in cables causes, fire., Clothing and anything else which might catch fire should be, kept well away from heaters. Make sure that the heater is, shut off at the end of the working day., Highly flammable liquids and petroleum mixtures (thinner,, adhesive solutions, solvents, kerosene, spirit, LPG gas, etc.) should be stored in the flammable material storage, area., Blowlamps and torches must not be left burning when they, are not in use., Extinguishing fires: Fires are classified into four types in, terms of the nature of fuel., , Fuel: Any substance, liquid, solid or gas will burn, if there, is oxygen and high enough temperatures., Heat: Every fuel will begin to burn at a certain temperature., It varies and depends on the fuel. Solids and liquids give off, vapour when heated, and it is this vapour which ignites., Some liquids do not have to be heated as they give off, vapour at normal room temperature say 150C, eg. petrol., Oxygen: Usually exists in sufficient quantity in air to keep, a fire burning., Extinguishing of fire: Isolating or removing any of these, factors from the combination will extinguish the fire. There, are three basic ways of achieving this., •, , Starving the fire of fuel removes this element., , •, , Smothering - ie. isolate the fire from the supply of, oxygen by blanketing it with foam, sand etc., , •, , Cooling - use water to lower the temperature. Removing, any one of these factors will extinguish the fire., , Different types of fires (Fig 2, Fig 3 Fig 4 & Fig 5) have to, be dealt with in different ways and with different extinguishing, agents., An extinguishing agent is the material or substance used, to put out the fire, and is usually (but not always) contained, in a fire extinguisher with a release mechanism for spraying, into the fire., It is important to know the right type of agent for extinguishing, a particular type of fire; using a wrong agent can make, things worse.There is no classification for ‘electrical fires’, as such, since these are only fires in materials where, electricity is present., , Preventing fires: The majority of fires begin with small, outbreaks which burn unnoticed until they have a secure, hold. Most fires could be prevented with more care and by, following some simple common sense rules., 2, , Copyright @ NIMI Not to be Republished
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Fuel, , Extinguishing, Most effective ie. cooling with water. Jets of water, should be sprayed on the base of the fire and then, gradually upwards., , Should be smothered. The aim is to cover the entire, surface of the burning liquid. This has the effect of, cutting off the supply of oxygen to the fire., Water should never be used on burning liquids., Foam, dry powder or CO2 may be used on this type, of fire., , Extreme caution is necessary in dealing with liquefied, gases. There is a risk of explosion and sudden, outbreak of fire in the entire vicinity. If an appliance, fed from a cylinder catches fire - shut off the supply, of gas. The safest course is to raise an alarm and, leave the fire to be dealt with by trained personnel., Dry powder extinguishers are used on this type of, fire., , Special powders have now been developed which, are capable of controlling and/or extinguishing this, type of fire., The standard range of fire extinguishing agents is, inadequate or dangerous when dealing with metal, fires., Fire on electrical equipment., Halon, Carbon dioxide, dry powder and vapourising, liquid (CTC) extinguishers can be used to deal with, fires in electrical equipment. Foam or liquid (eg., water) extinguishers must not be used on electrical, equipment under any circumstances., , IT & ITES : COPA - Related Theory for Exercise 1.01.01 & 1.01.02, , Copyright @ NIMI Not to be Republished, , 3
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Many types of fire extinguishers are available with different, extinguishing ‘agents’ to deal with different classes of fires., (Fig 1), , Dry powder extinguishers (Fig 4): Extinguishers fitted, with dry powder may be of the gas cartridge or stored, pressure type. Appearance and method of operation is the, same as that of the water-filled one. The main distinguishing feature is the fork shaped nozzle. Powders have been, developed to deal with class D fires., , Water-filled extinguishers: There are two methods of, operation. (Fig 2), , Carbon dioxide (CO2): This type is easily distinguished, by the distinctively shaped discharge horn. (Fig 5)., , •, , Gas cartridge type, , •, , Stored pressure type, , With both methods of operation the discharge can be, interruted as required, conserving the contents and, preventing unnecessary water damage., Foam extinguishers (Fig 3):These may be of stored, pressure or gas cartridge types. Always check the operating, instructions on the extinguisher before use., , Suitable for Class B fires. Best suited where contamination, by deposits must be avoided. Not generally effective in, open air., Always check the operating instructions on the container, before use. Available with different gadgets of operation, such as - plunger, lever, trigger etc., Halon extinguishers (Fig 6): These extinguishers may be, filled with carbon-tetrachloride and Bromochlorodifluoro, methene (BCF). They may be either gas cartridge or stored, pressure type., , Most suitable for, • flammable liquid fires, •, , running liquid fires., , Must not be used on fires where electrical equipment is, involved., , 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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They are more effective in extinguishing small fires involving, pouring liquids. These extinguishers are particularly suitable, and safe to use on electrical equipment as the chemicals, are electrically non-conductive., The fumes given off by these extinguishers are, dangerous, especially in confined space., The general procedure in the event of a fire:, •, , Raise an alarm., , •, , Turn off all machinery and power (gas and electricity)., , •, , Close the doors and windows, but do not lock or bolt, them. This will limit the oxygen fed to the fire and prevent, its spreading., , •, , Try to deal with the fire if you can do so safely. Do not, risk getting trapped., , •, , Anybody not involved in fighting the fire should leave, calmly using the emergency exits and go to the, designated assembly point. Failure to do this may, mean that some person being unaccounted for and, others may have to put themselves to the trouble of, searching for him or her at risk to themselves., , Practice on fire extinguishers, Objectives: At the end of this lesson you shall be able to, • state about the selection of the fire extinguishers according to the type of fire, • state the method of operation of the fire extinguisher, • explain how to extinguish the fire., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished, , 5
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PROCEDURE (Fig 1), , •, , •, , Alert people sorrounding by shouting fire, fire, fire when, observe the fire., , •, , Inform fire service or arrange to inform immediately., , •, , Open emergency exist and ask them to go away., , •, , Put “off” electrical power supply., , Aim the extinguisher nozzle or hose at the base of the, fire (this will remove the source of fuel fire) (Fig 4), , Don’t allow people to go nearer to the fire, •, , Analyze and identify the type of fire. Refer Table1., Table-1, Class ‘A’, , Wood, paper, cloth,, solid material, , Class ‘B’, , Oil based fire (grease,, gasoline, oil) liquefiable, gases, , Class ‘C’, , Gas and liquefiable, , Keep your self low, •, , Squeeze the handle lever slowly to discharge the agent, (Fig 5), , •, , Sweep side to side approximately 15 cm over the fuel, fire until the fire is put off (Fig 5), , gases, Class ‘D’, , Metals and electrical, equipment, , Assume the fire is ‘B; type (flammable liquifable solids), •, , Slect CO2 (Carbon di oxide) fire extinguisher., , •, , Locate and pickup, CO2 fire extinguisher. Click for its, expiry date., , •, , Break the seal (Fig 2), Fire extinguishers are manufactured for use, from the distance., Caution, • While putting off fire, the fire may flare up, • Do not be panick belong as it put off promptly., • If the fire doesn’t respond well after you have, used up the fire extinguisher move away yourself, away from the fire point., , •, , Pull the safety pin from the handle (Pin located at the, top of the fire extinguisher) (Fig 3), , • Do not attempt to put out a fire where it is, emitting toxic smoke leave it for the professionals., • Remember that your life is more important than, property. So don’t place yourself or others at risk., In order to remember the simple operation of the, extinguisher. Remember P.A.S.S. This will help, you to use the fire extinguisher., P for Pull, A for Aim, S for Squeeze, S for Sweep, , 6, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.2.05, COPA - Introduction to computer components, Introduction to computers, Objectives : At the end of this lesson you shall be able to, • define and classify computers, • list the advantages and limitations of computers, • list the applications of computer, • describe the voltages and currents in the computer., Computer - Definitions, , Fig 1, , A computer is an electronic machine, operating under, the control of instructions stored in its own memory that, can accept data (input), manipulate the data according, to specified rules (process), produce results (output), and, store the results for future use., Technically, a computer is a programmable machine., This means it can execute a list of programmed, instructions and respond to new instructions that it is, given., History of Computer, Charles babbbage’s machine, , The Analytical Engine had four parts. A mill, which was, the section which did the calculations, essentially the, CPU; the store, were the information was kept recorded,, essentially the memory; the reader, which would allow, data to be entered using punched cards, essentially the, keyboard, and the printer., Hence, Charles Babbage is considered as the "Father, of the Computer" as in fig-1., The generations of computers are characterized by a, major technological development that fundamentally, changed the way computers operate, resulting in, increasingly smaller, cheaper, more powerful and more, efficient and reliable devices. The various generations, of computers are listed below:, First Generation (1946-1954): In 1946 the digital, computer using electronic valves (Vacuum tubes) are, known as first generation computers. The first 'computer', to use electronic valves i.e. vacuum tubes. The high, cost of vacuum tubes prevented their use for main, memory. They stored information in the form of, propagating sound waves., The vacuum tube consumes a lot of power. These, computers were large in size and writing programs on, them was difficult. Some of the computers of this, generation were:, , CP110111, , The working principles of today's computers were, provided by an English mathematician Charles Babbage, around 1833's invented a machine called the "Analytical, Engine". A machine which could calculate and print tables, of functions using limited techniques., , Mark I :The IBM Automatic Sequence Controlled, Calculator (ASCC), called the Mark I by Harvard, University, was an electro-mechanical computer. Mark, I is the first machine to successfully perform a long, services of arithmetic and logical operation. Mark I is, the First Generation Computer., ENIAC: It was the first electronic computer built in 1946, at University of Pennsylvania, USA by John Eckert and, John Mauchy. It was named Electronic Numerical, Integrator and Calculator (ENIAC). The ENIAC was 3050 feet long, weighted 30 tons, contained 18,000 vacuum, tubes, 70,000 resisters, 10,000 capacitors and required, 150,000 watts of electricity. Today computer is many, times as powerful as ENIAC, still size is very small., EDVAC: It stands for Electronic Discrete Variable, Automatic Computer and was developed in 1950. The, concept of storing data and instructions inside the, computer was introduced here. This allowed much faster, operation since the computer had rapid access to both, data and instructions. The other advantage of storing, instruction was that computer could do logical decision, internally. The EDVAC was a binary serial computer, with automatic addition, subtraction, multiplication,, programmed division and automatic checking with an, ultrasonic serial memory., , Copyright @ NIMI Not to be Republished, , 7
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EDSAC: It stands for Electronic Delay Storage, Automatic Computer and was developed by M.V., Wilkes at Cambridge University in 1949. The EDSAC, is the first stored-program computer. The EDSAC, performed computations in the three millisecond range., It performed arithmetic and logical operations without, human intervention. The key to the success was in the, stored instructions which it depended upon solely for its, operation., , • Transistors were used instead of Vacuum Tube., • Processing speed is faster than First Generation, Computers (Micro Second), , • Smaller in Size (51 square feet), • The input and output devices were faster., , This machine marked the beginning of the computer, age., , Third Generation (1964-1977):By the development of a, small chip consisting of the capacity of the 300 transistors., These Integrated Circuits (IC)s are popularly known as, Chips., , UNIVAC-1: It stands for Universal Automatic, computer and it was the First commercial computer, developed by United States In 1951. The machine was, 25 feet by 50 feet in length, contained 5,600 tubes, 18,000, crystal diodes, and 300 relays. It utilized serial circuitry,, 2.25 MHz bit rate, and had an internal storage capacity, 1,000 words or 12,000 characters., , A single IC has many transistors, registers and capacitors, built on a single thin slice of silicon. So it is quite obvious, that the size of the computer got further reduced. Some, of the computers developed during this period were IBM360, ICL-1900, IBM-370, and VAX-750. Higher level, language such as BASIC (Beginners All purpose, Symbolic Instruction Code) was developed during this, period., , The UNIVAC was used for general purpose computing, with large amounts of input and output. The UNIVAC, was also the first computer to come equipped with a, magnetic tape unit and was the first computer to use, buffer memory., Limitations of First Generation Computer, Followings are the major drawbacks of First generation, computers., , Computers of this generation were small in size, low cost,, large memory and processing speed is very high. Very, soon ICs were replaced by LSI (Large Scale Integration), which consisted about 100 components., An IC containing about 100 components is called LSI as, in (Fig 2)., Features, , • They used valves or vacuum tubes as their main, electronic component., , • They were large in size, slow in processing and had, less storage capacity., , • They consumed lots of electricity and produced lots, of heat., , • Their computing capabilities were limited., • They were not so accurate and reliable., • They used machine level language for programming., • They were very expensive., Second Generation (1955-1964): The second-generation computer used transistors for CPU components, and ferrite cores for main memory&magnetic disks, for secondary memory. They used high-level languages, such as FORTRAN (1956), ALGOL (1960) & COBOL, (1960 - 1961). Input Output (I/O)processor was included, to control I/O operations., Manufacturing cost was also very low. Thus the size of, the computer got reduced considerably., It is in the second generation that the concept of Central, Processing Unit (CPU), memory, programming language, and input and output units were developed. Some of the, second generation computers are IBM 1620, IBM, 1401,CDC 3600., 8, , • They used Integrated Circuit (IC) chips in place of the, transistors., , • Semi conductor memory devices were used., • The size was greatly reduced, the speed of processing, was high, and they were more accurate and reliable., , • Large Scale Integration (LSI) and Very Large Scale, Integration (VLSI) were also developed., , • The mini computers were introduced in this generation., • They used high level language for programming., Fourth Generation (1978 - present): An IC containing, about 100 components is called LSI (Large Scale, Integration) and the one, which has more than 1000 such, components, is called as VLSI (Very Large Scale, Integration)., It uses large scale Integrated Circuits(LSIC) built on a single, silicon chip called microprocessors. Due to the, development of microprocessor it is possible to place, computer's centralprocessing unit(CPU) on single chip., These computers are called microcomputers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Later very large scale Integrated Circuits(VLSIC) replaced, LSICs. Thus the computer which was occupying a very, large room in earlier days can now be placed on a table., The personal computer (PC) that you see in your school, is a Fourth Generation Computer Main memory used fast, semiconductors chips up to 4 M bits size. Some of the, Fourth generation computers are IBM PC, AppleMacintosh, etc., , Fig 3, , Hard disks were used as secondary memory. Keyboards,, dot matrix printers etc. were developed. Operating System, (OS)-such as MS-DOS, UNIX, Apple's Macintosh were, available. Object oriented language, C++ etc were, developed., Features, , • They used Microprocessor (VLSI) as their main, switching element., , • They are also called as micro computers or personal, computers., , • Their size varies from desktop to laptop or palmtop., • They have very high speed of processing; they are, 100% accurate, reliable, diligent and versatile., , • They have very large storage capacity., Fifth Generation (PRESENT AND FUTURE): 5th, generation computers use ULSI (Ultra-Large Scale, Integration) chips. Millions of transistors are placed in a, single IC in ULSI chips., 64 bit microprocessors have been developed during this, period.. Memory chips and flash memory up to 1 GB,, hard disks up to 600 GB & optical disks up to 50 GB have, been developed (fig. 3)., , CP110113, , CP110113, , Fifth generation computing devices, based on Artificial, Intelligence, are still in development, though there are some, applications, such as voice recognition, that are being used, today., Artificial Intelligence is the branch of computer science, concerned with making computers behave like humans., The term was coined in 1956 by John McCarthy at the, Massachusetts Institute of Technology. Artificial, intelligence includes:, , • Games Playing: Programming computers to play, games such as chess and checkers, , • Expert Systems: Programming computers to make, decisions in real-life situations (for example, some, expert systems help doctors diagnose diseases based, on symptoms), , • Natural Language: Programming computers to, understand natural human languages, , • Neural Networks: Systems that simulate intelligence, , by attempting to reproduce the types of physical, connections that occur in animal brains, , • Robotics: programming computers to see and hear, and react to other sensory stimuli, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 9
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Table - 1, GENERATION, , ELECTRONIC COMPONENT, , ADVANTAGES, , First, , Vaccum tube, , Helped in calculation, and computational work, , Second, , Transistor, , 1.Smaller size, 2.Less cost, 3.Better speed, 4.Low power consumption, and less heat generation, 5.Better storage capacity, 6.Better accuracy and, more reliability, , Third, , Integrated Circuits(IC), small & medium scale, , 1.Better in all aspects, 1.Initial problem withmanufaccompared to I & II, turers, 2.Used operating systems 2.No insight obtained into, and high level language, internal working, , Fourth, , VLSI or Microprocessor, , 1.Low cost, 2.Excellent speed and, reliability, 3.Computers close to man, , Fifth, (Knowledge, Information, Processing, Systems), , ULSI or Bio-Chips, , 1.Very cheap, , 1.Big size, 2.Very costly, 3.Slow speed, 4.Low accuracy, 5.Low storage, 6.High power requirements, 7.High heat generation, 8.High failure rate, 9.Used machine language, 10.No operating system, 1.Need air conditioning, 2.Constant maintenance, 3.No operating systems, 4.Later stage computers used, assembly languages, , 1.Less powerful than main, frame computers, , 1.New low level language, needed, , 2.super speeds, 3.Very high storage capacity, 4.Highly sophisticated OS, 5.posses intelligence and, decision making ability, , Classification of computers, Computers are classified according to the following criteria:, , • Principle of Operation, • Computing Power, Memory Capacity and cost, • Technological Development, • Principle of operation, , It is a computer that measures continuously changing, physical quantities such as current, temperature,, pressure etc. and converts them into quantities which, can be used as data for computation. As these computers, deal with continuously varying quantities they will give, only approximate results. Its output is usually displayed, on a meter or scale. Analog computer has low memory, and fewer functions. These are used for engineering and, scientific applications., , •, , Analog computer, , • Thermometer, , •, , Digital Computer, , • Speedometer, , •, , Hybrid Computer, , • Analog clock, , Analog Computer, 10, , DISADVANTAGES, , Digital Computer, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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A digital computer works with digital data. Digital computer, uses binary number system. Binary number system, consists of only two digits '0' and '1'. A digital computer, represents data in digital signals. A '0' represents OFF, and a '1' represents ON. Digital computer performs, arithmetic and logical operations on data. It gives output, in digital form., , store results. They have large Memory (that is data storing, capacity). Today most of the computers used in offices, and homes are Digital computers., , • Special purpose computers, , Digital computers are very fast. These computers can, , • General purpose computers, , The digital computers are further divided into the, following two groups:, , Table 2, Analog Computers, , Digital Computers, , 1. Analog Computers Work on continuous values., 2 Analog Computers have low memory., 3 Analog computers have Slow speed., , Digital computers Work on discrete values., Digital computers have a very large memory, Digital computers have fast speed., , 4 Analog computers are less reliable., , Digital computers are more reliable., , 5 Analog computers used in engineering, , Digital computers are used in all fields of life., science and medical fields., , 6 Analog computers are used to calculate /, , Digital computers are used to calculate, , measure analog quantities like speed and, , mathematical and logical operations. It can, , temperature., , solve addition, subtraction, division,, multiplication and other mathematical and, statistical operations., , 7 Analog computers provide less accurate results., , Digital computers provide 100% accurate results., , 8 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 9 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 10 Examples of Analog computers are: thermometer,, , Examples of digital computers are:, , analog clock, speedometer etc., , Personal Computer, laptops, smart phones etc., , Special Purpose Computers, It is a computer designed to solve specific type of, problem. The computers used in ships and aircrafts, etc., General Purpose computers, It is a computer designed to solve a wide variety of, problems, A General purpose Computer can store, different programs and process them., The differences between analog and digital computers, are listed in table 2, Hybrid Computer (Fig. 4), A hybrid computer is a combination of both analog and, digital computer. Hybrid computer can handle both, analog and digital data. A hybrid computer combines the, best characteristics of both the analog and digital, computer. It can accept data in both analog and digital, form., Applications, Hybrid computer devices are used in hospitals that may, calculate patient's heart function, temperature and blood, pressure etc. This calculation may be converted into, , numbers and shown in digital form. For example, The Vital, Signs Monitoring unit also called (VSM) in short. It has, Blood Pressure monitor, ECG monitor, respiratory monitor,, and is also used for monitoring anesthesia., , • Hybrid computers are also used in spaceships and, missile system., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 11
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•, , Hybrid Computer Machines are generally used in, scientific applications, , •, , Hybrid computers are used for controlling industrial, processes., , Computers are classified on the basis of computing, power, memory capacity and cost., - Microcomputer or Personal Computer., - Mini Computer., - Mainframe Computer., - Super Computer., Micro Computers, Micro computer is also called personal computer. It was, introduced in 1970. Examples of personal computers are, PC and Apple Macintosh. The major types of personal, computers are desktop computer and portable computer., Desktop Computer, , Fig 6, , CP110116B, , These computers can easily fit on a table or desktop,, hence the name. These computers come in two models, or casings. In Desktop model, the system unit is placed, on the desktop or table. Monitor is placed on the system, unit. In Tower model, both monitor and system unit are, placed on the table as in (Fig 5)., , Palmtops have no keyboard but the screen serves both, as an input and output device. It easily fits in the hand of, the user., Uses of Micro Computer, The PC is the most common type of computer used in, the office. It is now widely used in many homes. These, are also used for business and engineering application., , Portable computer, Portable is a personal computer that can be carried from, one place to other easily. Notebook computer and, handheld computer (smart phone) are examples of, portable computers. Notebook computer is also called, laptop computer. Laptop computers are very small in, size and can be placed easily on lap., , Mini Computer, , Lap top computer or notebook computer, , Minicomputer can serve up to 4000 connected users, simultaneously. It is normally accessed by users via, personal computer or terminal. A device with a monitor, and keyboard is called terminal. It is also known as dumb, terminal. It has no processing power and cannot work as, stand-alone computer. Some of the minicomputers, models are VAX-8800, AS400, , The laptop computer or notebook computer will be as, shown in fig 6a and fig 6b.It is also called as tower model, computer., Palmtop Computer/Digital Diary /Notebook /PDAs:, A handheld computer (like smart phone) is also portable., Hand held computer is known as palmtop computer., 12, , Mini computers were introduced in the 1960s., Minicomputer is larger and more powerful computer than, personal computer. It can execute five million instructions, per second. It generally consists of two or more, processors., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Uses of Mini Computer, Mini computers are often used by small and medium-sized, companies to provide centralized store of information., Mainframe Computer, Mainframe computers were introduced in 1975. A, mainframe computer is a very large computer in size. It is, processors. It is designed to perform multiple tasks for, multiple users at the same time. Mainframe computers, can serve up to 50,000 users at the same time., , programs concurrently. The modern super computer, consists of thousands of microprocessors. Super computer, uses high-speed facilities such as satellite for online, processing., Sum of the super computers models are CRAY-XP, ETA10, Param and Deep Blue ., Advantages of computers, •, , A computer has a very high processing speed with high, reliability., , •, , Large volume of information can be stored in the, memory any particular data/program can be retrieved, immediately., , •, , Solution to a complicated problem is possible at a very, high speed., , •, , Processing of large volume of data saves a lot of clerical, work which reduces the processing cost., , Mainframe computers are used primarily by corporate, and governmental organizations for critical applications,, bulk data processing such as senses, industry and, consumer statistics, and transaction processing., , •, , Computers perform operations efficiently at, environments where presence of human being is not, possible such as furnace, poisonous atmosphere,, vacuum, unmanned satellite, etc., , Super computer, , Limitation of computers, , Super computers were introduced in 1980s. Super, computer is the fastest computer. Super computer is the, biggest in size and the most expensive in price than any, other computers., , •, , High initial cost., , •, , Input information has to be prepared in the form of, statements called program which requires a, considerable amount of knowledge., , •, , usage of computers will be economical only when there, is clerical data processing for large volume of data and, are repetitive in nature, , •, , It is a merely a machine it cannot correct errors on its, own., , The users access a mainframe computer through, terminal or personal computer. A typical mainframe, computer can execute 16 million instructions per second., Some of the main computers models are, •, •, , NEC 610, DEC 10, , Uses of Mainframe Computer, , It is the most sophisticated, complex and advanced, computer. It has a very large storage capacity. It can, process trillions of instructions in one second. Super, Computer is the fastest and most powerful computer of, a time. Supercomputers are very expensive., Supercomputers are used for highly calculation-intensive, tasks. Super computers are also used for specialized, applications that require immense amounts of, mathematical calculations., Applications of Super Computer, •, , Weather forecasting,, , •, , Animated graphics like in Hollywood movies,, , •, , Fluid dynamic calculations, , •, , Nuclear energy research, , •, , Space science, , •, , Weapon and missile design, , •, , Petroleum exploration, and etc., , Today, supercomputers are produced by traditional, companies such as Cray, IBM and Hewlett- Packard., Since October 2010, the Tianhe-1A supercomputer has, been the fastest in the world; it is located inChina., The main difference between a supercomputer and a, mainframe is that a supercomputer channels all its power, into executing a single program as fast as possible,, whereas a mainframe uses its power to execute many, , Functions of Computers, All computers are made up of following basic units as, shown in fig (7). They are as follows:1 Input Unit, 2 Central processing Unit (CPU), a) Arithmetic Logic Unit(ALU), b) Control Unit (CU), 3 Memory, 4 Output Unit, Input Unit, Computers need to receive data and instruction in order, to solve any problem. Therefore we need to input the, data and instructions into the computers. The input unit, consists of one or more input devices. Keyboard is the, one of the most commonly used input device. Some of, the input devices are listed in table 1., Input devices perform the following functions., •, , Accept the data and instructions from the outside world., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 13
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•, , Convert it to a form that the computer can understand., , •, , Supply the converted data to the computer system for, further processing., , Central Processing Unit (CPU) (Fig. 8), The central processing unit (CPU) is the electronic brain, , use in a computer or other digital electronic device., There are two types of memory in computer., •, •, , Primary Memory, Secondary Memory, , Output Unit, Output unit receive the informations from the processing, unit and provide the results in human readeable form., Output Devices, The some of the output devices are, • Monitor, • Printer, • Plotter, • Speaker, Applications of computers, , of the computer as in fig-8. The CPU in a personal computer, is usually a single chip. It organizes and carries out, instructions that come from either the user or from the, software. The processor is made up of many components., CPU performs the following functions:, •, •, •, , It performs all calculations., It takes all decisions., It controls all units of the computer., , Two typical components of a CPU are the following:, The arithmetic logic unit (ALU), which performs arithmetic, and logical operations., The control unit (CU), which extracts instructions from, memory and decodes and executes them, calling on the, ALU when necessary., Memory, Memory refers to the physical device used to store the, program or data on the temporary or permanent basis for, , 14, , Science: Scientists have been using computers to, develop theories and to analyse and test the data. The, high speed and accuracy of the computer allow different, scientific analyses to be carried out. They can be used, to generate detailed studies of how earthquakes affect, buildings or pollution affects weather pattern. Satellitebased applications have not been possible without the, use of computers. Moreover, it would not be possible to, get the information of the solar system and the cosmos, without computers., Education: Computers have also revolutionized the, whole process of education. Currently, the classrooms,, libraries and museums are efficiently utilizing computers, to make the education much more interesting. Unlike, recorded television shows, computer-aided education, (CAE) and computer-based training (CBT) packages are, making learning much more interactive., Medicine and Health Care: There has been an, increasing use of computers in the field of medicine., Now, doctors are using computers right from diagnosing, the illness to monitoring a patient's status during complex, surgery. By using automated imaging techniques, doctors, are able to look inside a person's body and can study, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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CP110117t1, , Fig 9, , each organ in detail (e.g. CT scans or MRI scans), which, was not possible few years ago. There are several, examples of special-purpose computers that can operate, within the human body such as cochlear implant, a, special kind of hearing aid that makes it possible for, deaf people to hear., Engineering/Architecture/Manufacturing: The, architects and engineers are extensively using computers, in designing and drawings. Computers can create objects, , that can be viewed from all the three dimensions. By using, techniques like virtual reality, architects can explore houses, that have been designed but not built. The manufacturing, factories are using computerized robotic arms to perform, hazardous jobs. Besides, computer-aided manufacturing, (CAM) can be used in designing the product, ordering the, parts and planning production. Thus, computers help in, coordinating the entire manufacturing process., , IIT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 15
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Entertainment: Computers are finding greater use in, entertainment industry. They are used to control the, images and sounds. The special effects, which, mesmerize the audience, would not have been possible, without the computers. In addition, computerized, animation and colourful graphics have modernized the, film industry., , Banking: Computers are extensively used in the field of, banking and finance. People can use the ATM (automated, teller machine) services 24 hours a day to deposit and, withdraw cash. When different branches of the bank are, connected through computer networks, the inter branch, transactions such as cheque and draft can be performed, without any delay., , Communication: E-mail or electronic mail is one of the, communication media in which computer is used. Through, e-mail, messages and reports are passed from one person, to one or more persons with the aid of computer and, telephone line. The advantage of this service is that while, transferring the messages it saves time, avoids wastage, of paper and so on. Moreover, the person who is receiving, the messages can read the messages whenever he is, free and can save it, reply it, forward it or delete it from the, computer., , Railway Reservation System, , Business Application: This is one of the important uses, of the computer. Initially, computers were used for batchprocessing jobs, where one does not require the, immediate response from the computer. Currently,, computers are mainly used for real-time applications (like, at the sales counter) that require immediate response, from the computer. There are various concerns where, computers are used such as in business forecasting, to, prepare pay bills and personal records, in banking, operations and data storage, in various types of life, insurance business and as an aid to management., Businesses are also using the networking of computers,, where a number of computers are connected together, to share the data and the information. Use of e-mail and, the Internet has changed the ways of doing business., Publishing: Computers have created a field known as, desktop publishing (DTP). In DTP, with the help of, computer and a laser printer one can perform the, publishing job all by oneself. Many of the tasks requiring, long manual hours such as making table of contents and, index can be automatically performed using the, computers and DTP software., , 16, , Using this system, the user can perform following, operations through online. (web site: www.irctc.co.in), •, •, •, •, , search the train and its timings, check seats and birth availability, booking and cancelling tickets, status of PNR (Passenger Name Record), , Telephone / Electricity Board Billing:, The users can do the following operations through online, by using this system. (Web site: portal.bsnl.in - BSNL), • Register the telephone / electricity board number, • Check and pay the bill amount, • Register the complaints, E-Governance, E-Governance implies technology driven governance., E-Governance is the application of Information and, Communication Technology (ICT) for delivering, government services, exchange of information, communication transactions, integration of various standalone systems and services between Government-toCitizens, (G2C),, Government-toBusiness(G2B),Government-to-Government( G2G) as, well as back office processes and interactions within the, entire government frame work., E-Governance covers all the sectors with a view to, providing hassle free, transparent and efficient service, to the common man (both in urban and rural areas)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise1.2.06, COPA - Introduction to computer components, Introduction to CPU architecture and motherboard, Objectives: At the end of this lesson you shall be able to, • state what is hardware and test the internal and external hardware, • brief the listed hardware, • state what is partitions and their types, • explain the booting and its procedures., Computer Hardware, The physical units of a computer are called as the, hardware of a computer., Internal hardware examples, •, , Blu-Ray, CD-ROM, and DVD, , •, , CPU, , •, , Hard drive, , •, , Motherboard, , •, , RAM, , •, , Sound card, , •, , Video card, , •, , SMPS, , External hardware examples, •, , Flat-panel, Monitor, and LCD, , •, , Keyboard, , •, , Mouse, , •, , Printer, , •, , Scanner, , CPU & ALU, Central Processing Unit (CPU) is the heart of the, Computer. It is the hardware,that carries out the, instructions of a computer program by performing the, basic arithmetical, logical, and input/output operations, of the system., , Most connectors are separated, permitting the cable to, be plugged in only in the correct direction. The keyboard, and mouse use "PS2" (Personal System 2) connectors., The PS2 connectors are color-coded. The purple, connector is for the keyboard. The green connector is, for the mouse., •, , PS/2 Ports: Standard keyboards and mouse often, connect to the computer via the PS/2 ports. To plug, in a keyboard or mouse cable, first match the cable, to the connector. Then push the cable into the, connector. Be sure not to force the connector because, you will end up bending the pins, , •, , Serial & Parallel Ports: The serial port and parallel, port allow connections to printers and other external, devices. To transfer a byte through a serial port, eight, bits are queued and sent bit by bit. However, in a, parallel port, all the eight bits are transferred, simultaneously, , •, , The parallel port, serial port, and video port all use "D", type connectors (DB-25M, DB-9M and DB-15F, respectively). These are called D connectors because, of their shape, which permits the cables to be plugged, in only one way., , CPU Ports and Connectors, A port is a connector at the back of a Computer cabinet, where you plug in an external device such as a printer,, keyboard, scanner, modem etc. This allows instructions, and data to flow between the computer and the device., The computer ports are also commonly referred to as, the Input/output ports (I/O ports). These ports can be, either serial or parallel. Fig 1 shows the commonly, available ports on a personal computer., , Copyright @ NIMI Not to be Republished, , 17
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USB (Universal serial bus) Ports, , The System Unit and Its Components, , Devices like digital cameras, scanners and printers often, connect to the motherboard via the USB ports. A USB, connector's distinctive rectangular shape makes it easily, recognizable., , The system unit is a box-like unit filled with a number of, useful components, each performing a discrete function., These components work together to accomplish the main, function of the computer, viz. accept and process input, and deliver output. This section will elaborate on these, components one by one. Fig 3 shows the various, components of the system unit., , USB has a number of features that makes it particularly, popular on PCs. First, USB devices are hot swappable., You can insert or remove them without restarting your, system, LAN(Local Area Network) Port: The LAN port is used, to connect the PC to a local network or to high speed, Internet services., , Fig 3, , VGA (Video Graphics Array) Ports: The VGA port, provides access to integrated video., Audio ports: It provides access to integrated audio., The audio jacks are the most confusing connectors on, the back panel. Although the jacks are sometimes colorcoded, the devices that plug into them rarely., CPU front Panel shown Fig 2., , CP11011B, , Fig 2, , Power Supply, The power supply connects to nearly every device in the, PC to provide power. It is located at the rear of the case., The system unit draws power from the AC mains through, a power protection device., , It may contain the following parts., , • Power On/Off Switch, • Power Indicator, • CD/DVD Drive, • CD/DVD Drive Open/Close Button, • CD/DVD Drive indicator, • Floppy Disk Drive, • Floppy Disk Drive Indicator, • USB Ports, • Audio and Mic connectors, Design of CPU Cabinets may vary based on, the manufacturer., , 18, , This power is not directly supplied to the internal, components. Instead, one of the components, called the, internal power supply, converts the AC input into DC, output of 5 and 12 volts. Normally, the internal power, supply is referred to as Switched Mode Power Supply, (SMPS)., The SMPS provides cable connectors to supply the, required voltage to the other internal components like, the floppy drives, the hard disk drive, the motherboard, and external device such as the keyboard. The ON/OFF, switch of the system unit is actually a part of the SMPS., Fan, The SMPS has a small fan, called the exhaust fan,, attached to SMPS(Fig. 4). This fan rotates as long as, the computer is switched on. Its function is to cool the, SMPS unit., Drive Bays: The 5.25" and 3.5" drive bays house the, many kinds of storage devices a computer might contain., Expansion Slots: An expansion slot is a slot located, inside a computer mother board that allow additional, peripharals to be connected to it., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Power Port: Power is delivered to drives via cables that, plug into the power port on the drives., , Fig 4, , Peripheral cards slot, The peripheral cards are the spare expansion slots, available on the mother board on which peripheral cards, can be inserted., , CP11011C, , The following are the peripheral cards, , Memory Slot, , •, , Sound card, , •, , Video card, , •, , Modam, , •, , Wireless network, , Fig. 7 shows the peripheral card, designed with a PCI, (Peripheral component interconnect) connector., Fig 7, , Memory Slot is used to insert a Random Access, Memory(RAM) shown in fig 5, , Storage Drivers, Storage drivers such as hard drives, optical drives and, floppy drives all connect to the motherboard via cables, and is mounted inside the computer., IDE & SATA Cables: Fig 6 shows two hard disk drives, that connect in different ways to the motherboard. One, uses the older IDE cable connection while the other uses, SATA(Serial Advanced Technology Attachment) cable, which provides for faster hard drive access., , CP11011F, , CP11011D, , Fig 5, , Motherboard, The motherboard is a printed circuit that is the foundation, of a computer and allows the CPU, RAM, and all other, computer hardware components to function with each, other as on fig 8., Fig 8, , CP11011G, , Fig 6, , CP11011E, , "www. dget.gov.in", , The motherboard is the primary component of the entire, system. A mother board is a large board containing a, number of tiny electronic circuits and other components, are visible. All peripheral devices are connected to the, motherboard. The components of the motherboard are:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 19
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This means you can upgrade to a newer version of DOS, without changing the BIOS. PC BIOS that can handle, Plug-and-Play (PnP)devices are known as PnPBIOS,, These BIOS are always implemented with flash memory, rather than ROM., , •, , Keyboard / mouse port, , •, , Parallel and Serial port, , •, , Processor Socket, , •, , AGP Slot, , CMOS Battery, , •, , PCI Slots, , •, , ISA Slot, , •, , CMOS Battery, , CMOS (Complementary Metal-Oxide-Semiconductor) is, the term usually used to describe the small amount of, memory on a computer motherboard that stores the BIOS, settings., , •, , Data Card Connector, , •, , Memory Slots, , •, , Floppy Port, , •, , Fan Header, , •, , Main Power Connector, , Most CMOS batteries will last the lifetime of a, motherboard (up to 10 years in most cases) but will, sometimes need to be replaced. Incorrect or slow system, date and time and loss of BIOS settings are major signs, of a dead or dying CMOS battery., ISA slot: (Industry Standard Architecture) It is the, standard architecture of the Expansion bus. Motherboard, may contain some slots to connect ISA compatible cards., , Floppy Port :The floppy drive connects to the computer, via a 34-pin ribbon cable, which in turn connects to the, motherboard. A floppy controller is one that is used to, control the floppy drive., RAM slots: Random-Access Memory (RAM) stores, programs and data currently being used by the CPU., RAM is measured in units called bytes. RAM has been, packaged in many different ways, •, , SIMM-Single inline memory module -32 or 72 Pin, , •, , DIMM- Dual Inline Memory module -168 pin., , In most of the PC's uses of the DIMM module, ROM BIOS Chip: This means Read Only Memory Basic, Input-Output System., The built-in software that determines what a computer, can do without accessing programs from a disk. On PCs,, the BIOS contains all the code required to control the, keyboard,, display, screen,, disk, drives,, serialcommunications, and a number of miscellaneous, functions., The BIOS is typically placed in a ROM chip that comes, with the computer (it is often called a ROM BIOS). This, ensures that the BIOS will always be available and will, not be damaged by disk failures., It also makes it possible for a computer to boot itself., Because RAM is faster than ROM, though, many, computer manufacturers design systems so that the, BIOS is copied from ROM to RAM each time the, computer is booted. This is known asshadowing., Many modern PCs have flash BIOS, which means that, the BIOS have been recorded on a flash memory chip,, which can be updated if necessary. The PC BIOS is fairly, standardized, so all PCs are similar at this level (although, there are different BIOS versions). Additional DOS, functions are usually added through software modules., 20, , PCI slot : Intel introduced the Peripheral Component, Interconnect bus protocol. The PCI bus is used to, connect I/O devices to the main logic of the computer., PCI bus has replaced the ISA bus. PC motherboards, have one PCI slot but generally more than one., The PCI bus architecture is a processor-independent bus, specification that allows peripherals to access system, memory directly without using the CPU., AGP slot: The Accelerates Graphics Port (AGP) is a, high-speed point-to-point channel for attaching a video, card to a computer's motherboard., Power supply plug in, The Power supply, as its name implies, provides the, necessary electrical power to make the PC (Personal, Computer) operate. The power supply takes standard, 110-V AC power and converts into +/-12-Volt, +/-5-Volt,, and 3.3-Volt DC power. The power supply connector has, 20-pins, and the connector can go in only one direction., Hard Disk and Partitions, Partitioning is a process of dividing the Hard disk into, several chunks, and uses any one of the portion or, partition to install OS or use two or more partitions to, install multiple OS.., But it can always have one partition, and use up the, entire Hard disk space to install a single OS, but this will, become data management nightmare for users of large, Hard disks., Now, because of the structure of the Master Boot Record, (MBR), has only four partitions, and these four partitions, are called Primary Partitions., Extended Partition is not a usable partition by itself,, but it's like a "container" and it is used to hold, LogicalDrives!That is this Extended Partition can be, subdivided into multiple logical partitions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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In order to boot into a Partition, it must be designated, as bootable partition or Active Partition. Active Partition, is that partition which is flagged as bootable or which, contains OS, this is generally a Primary Partition., , Fig 9, , Types of Partitions:, •, , Master, , •, , Partition, , •, , Extended and, , •, , Logical Extended, , Master Boot Record (MBR): MBR is a small 512 bytes, partition which is at the first physical sector of the hard, disk. The location is denoted as CHS 0,0,1 meaning 0th, Cylinder, 0th Head and 1st Sector., MBR contains a small program known as bootstrap, program which is responsible for booting into any OS., MBR also contains a table known as Partition Table., This Partition Table is a table which lists the available, Primary Partitions in the hard disk. Partition table, considers whole Extended Partition as one Primary, partition and lists it in the table!, So a Partition table can have two possible entries:•, , Up to 4 Primary Partitions., , •, , Up to 3 Primary Partitions and 1 Extended, Partition.(Total not exceeding 4) ., , Partition Boot Sector (PBR): This is the logical first, sector, that is sector at the start of a Primary Partition., This is also 512 byte area, which contains some programs, to initialize or run OS files. All Primary Partitions have, its own PBRs., Extended Boot Sector (EBR): This is the logical first, sector, that is the sector at the start of the Extended, Partition. This EBR contains a Partition Table, which lists, the available Logical Partitions inside Extended Partition., That is it contains the Starting addresses of each Logical, Partitions., Logical Extended Boot Sector (LEBR): This is the, logical first sector residing at the start of each Logical, Partition. This is similar to PBR for Primary Partitions., Booting, Booting is a process of loading the operating system, (OS) and checking all the system software and hardware, those are installed in the computer., Booting procedure of Windows operating system, Functions of BIOS, The first process starts, when the computer switched on, Basic Input Output System (BIOS) perform two functions,, to conduct POST and read MBR (Fig 9)., , POST - POST stands for Power OnSelf Test. POST, checks all the hardware devices connected to a computer, like RAM, hard disk etc and make sure that the system, can run smoothly with those hardware devices. If the, POST is a failure the system halts with a beep sound., Now BIOS checks the boot priority. We can set the, boot priority as CD drive, hard disk or floppy drive., MBR - The next duty of BIOS is to read the MBR. MBR, stands for Master Boot Record and it's the first sector on, a hard disk. MBR contains the partition table and boot, loader., Functions of Boot loader, Now BIOS has passed the control to boot loader and, boot loader is a small program which loads kernel to, computers memory. Actually there are two stages of boot, loaders, stage 1 boot loader and stage 2 boot loader., The stage 1 boot loaderis a link to the stage 2 boot loader., The stage 2 boot loader resides in the boot partition and, it loads the kernel to memory., Boot files and functions, There are three boot files in a Windows operating system, and they are NTLDR, NTDETECT.COM and Boot.ini., The boot files are found in the active partition of hard, disk and its normally C drive in a Windows machine., NTLDR - NTLDR stands for NT Loader and it's the, second stage boot loader. The path of NTLDR is, C:\Windows\i386\NTLDR., Boot.ini - Boot.ini contains the configuration files of, NTLDR. When the operating system is loaded we cannot, pass any arguments to kernel, so those arguments are, passed through boot.ini. You can edit boot.ini by opening, through notepad. The path of Boot.ini is C:\boot.ini., NTDETECT.COM, This file detects hardware's and passes information to, NTLDR. Using the collected information the NTLDR, creates a hardware key and this key is used to detect, hardware's., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 21
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A new hardware key is generated after each reboot of the, operating system and that's why system asks to reboot, after installation of a new hardware. The hardware keys, created by NTLDR can be found in Windows registry at, HKEY_LOCAL_MACHINE ' HARDWARES., Kernel and its functions, After executing the functions of boot files the control is, passed to Kernel. ntoskrnal.exe is the kernel file in a, Windows machine and its path is C:\Windows\system, 32\ntoskrnal.exe., Kernel acts as a layer between software and hardware., The library file hal.dll (C;\Windows\system32\hal.dll) helps, Kernel to interact with hardware's. HAL stands for Hardware, Abstraction Layer and this hal.dll file is machine specific., Now the drivers for hardware's are loaded from the file, C:\Windows\system32\config\system and the Kernel is, loaded to primary memory., Services and log in procedure, When kernel is loaded in the primary memory, services, for each process is started and the registry entry for those, services can be found at HKEY_LOCAL_MACHINE System - Current control set - Services., Winlogon.exe (C:\Windows\system32\winlogon.exe) is, the last service started during this process., Winlogon.exe starts the log in procedures of windows, machine. It first calls the library file msgina.dll, (C:\Windows\system32\msgina.dll)., MSGINA stands for Microsoft Graphics Identification and, Authentication and it provides the log in window. Now, msginal.dll passes the control to LSA (Local Security, Authority), it verifies the username and password from, the SAM file. SAM (Security Accounts Manager) contains, the information about all users created in a Windows, operating system., Now the booting procedure is over and it has reached, the desktop of Windows operating system., Voltage: Every electric charge is capable of doing work, by moving another charge either by attraction or by, repulsion. This ability of a charge to do work represents, its potential. Voltage is generated by the separation of, charges. Voltage or electric potential is the state of, separated charges striving to neutralize each other. The, unit of electric potential is volt. Potential difference is, necessary to cause flow of electric current., Methods of voltage generation: Voltage can be generated, by several ways. Some methods of generating coltage, are:, , • Voltage from chemical reactions, Measuring voltage: Voltage exists between any two, points with different levels of charge. Voltage between, any two points can be measured using an instrument, called VOLTMETER. Meters used to measure current is, called Ammeter. There are meters which can be used to, measure voltage and current and a few other electrical, parameters like resistance. Such meters are called, MULTIMETERS., Types of voltage: As discussed in above paragraphs there, are several sources by which voltage can be developed., Depending upon the voltage source, the voltage developed, can be,, Direct voltage: It is of constant magnitude. It remains at, the same amplitude from the moment it is switched ON, till the moment it is switched - OFF., Alternating voltage: In this type, voltage source changes, its polarity regularly and therefore the direction of, developed voltage., A mixed voltage is a combination of direct voltage and, alternating voltage. The level of voltage is not constant., It varies around a mean value., Electric Current: Electric current is produced when, electric charges move in a definite direction. This, movement is not only of negative charges but also of, positive charges. The strength of electric current is the, quantity of charge which flows across a given cross, section of a conductor every second. The unit of current, strength is Ampere., Current strength = Quantity of charge/time, Measuring current: Electric current is the flow of charge,, in a conductor. So, to measure current must pass through, the measuring device. The current measuring instrument, is called the ammeter of the current meter. There are, different types of ammeters used for measuring different, quantities of current., Types of current: Voltage causes electrical current to, flow. If the cause of current flow is a direct voltage source,, then the current caused by its called direct current (d.c)., On the otherhand, then the current caused is referred as, the alternating current. If a mixed voltage AC and DC) is, applied to an electrical circuit, a mixed current (AC and, DC) will flow through the circuit., Types of power supply: Irrespective of how the, electricity is generated, electricity can be classified into, two types., •, , Alternating current, generally known as AC supply., Direct current, generally known as DC supply., , •, , Voltage from friction, , •, , •, , Voltage from moving magnets or coils, , •, , Voltage from pressure or tension in crystals, , •, , Voltage from heat, , AC supply: The term alternating current supply is given to, a supply source that makes current to flow through a circuit, which reverses or alternates its direction periodically., , •, , Voltage from light, , 22, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Advantages of AC supply, •, , Reduced transmission loss over long distances., , •, , Voltage levels can be changed using simple devices, called transformers., , •, , Reduced severity of electrical shock., , •, , Generating equipments are simple and cheaper, , •, , Can be easily converted to DC supply., , DC supply: The term direct current supply is given to a, supply source that makes current to flow through a circuit, in one direction only. Example of DC supply is batteries., Some types of generators are also designed to give d.c., supply. Such generators are called DC generators., Low tension (LT) voltage: The domestic voltage of 240, volts AC (generated and supplied by hydro or Thermal, or Nuclear generating stations) is called the low tension, (LT) voltage. LT lines enters residential buildings from, electricity poles called as service connection. This 240, volts is used to light up the lamps, run fans etc in homes., To connect electrical appliances at home, 240V AC is, available in either two-pin or three - pin sockets. This LT, voltage of 240 volts, 50Hz is also used to supply electrical, and electronic gadgets such as Iron box, washing, machine, personal computer etc., Phase, Neutral and Earth points of LT supply: The, domestic AC mains supply of 240V, 50Hz, is available, at consumers residence either in a 2-pin outlet (Phase Neutral) or in a 3-pin outlet (phase -Neutral and Ground)., These are commercially referred to as 2/3 pin sockets., These sockets look similar to the ones shown in Fig. 10., , recorders etc., Hence such gadgets does not need earth, pin/point on the socket., Iron box, washing machines, drill guns, Desk top computer, invariably need sockets with provision of earth pin, because, of the possibility of shock while using these equipments., Hence such equipments/gadgets make use of AC mains, socket with earth., Connection of 3-pin AC mains socket: Fig 11 shows, how the main supply is connected to the socket., Fig11, , Note that in a AC outlet be it a 2-pin or a 3-pin phase is, always connected to the socket through a switch. This, prevents the users from getting electrical shock when the, switch is put in off position., The standard voltage appearing across the 3-pin terminals, is shown in Fig12, Fig 12, , Fig 10, , Phase: The line or phase point in a socket, can be termed, as the point from where the electricity starts flowing into a, closed circuit., Neutral: The neutral point in the socket, can be termed, as the point which receives electricity from the closed, circuit., Earth / Ground: The ground (some call it Earth) point in, an electrical socket provides the easiest path for the, leakage current and other minor electrical defect currents, of appliances., Two pin mains sockets are used to supply main to such, equipments or apparatus or gadgets generally having its, cabinets/chassis made of plastic such as radio, tape, , The voltages across the pins of the socket can be measured, using an AC voltmeter or a multimeter in AC volts range., As a quick test to find out whether or not a socket is, delivering the AC supply as required, a simple instrument, called line tester which looks similar to a small screw, driver can be used. This instrument will have a small, bulb in it which glows if it is touched to the phase pin in, the socket. Ask your instructor to demonstrate the use of, such line tester to check a AC mains socket., Most Desk top computers need AC mains supply for its, operation. Although the mains supply available in the 3pin socket shown above can be used, mostly this AC, supply is cleaned fro spikes before connecting to, computers. The device used for cleaning the spikes in the, mains AC supply are called Spike Arrestors or Spike, busters., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 23
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Computers are used with spike busters because, AC spikes, are likely to damage the costly computers. In addition to, spike busters, most computers use other power safety, devices called the voltage stabilizers and uninterrupted, power supplies., , 24, , Power supply in computers: Power supply unit in, computers are firmly fitted on the processing unit cabinet, using torx screws. Generally there will be four such screws, fitted to fix the power supply init in the cabinet., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise : 1.3.07 - 1.3.11, COPA - Windows Operating System, Windows Operating System, Objective: At the end of this exercise you shall be able to, • list out the windows versions and features, Windows versions and its features, Microsoft Windows has seen nine major versions since, its first release in 1985. Over 29 years later, Windows, looks very different but somehow familiar with elements, that have survived the test of time, increases in, computing power and - most recently - a shift from the, keyboard and mouse to the touchscreen., Here's a brief look at the history of Windows, from its, birth at the hands of Bill Gates with Windows 1 to the, latest arrival under new Microsoft chief executive, SatyaNadella., , Apple's Macintosh and the Commodore Amiga graphical, user interfaces, coming pre-installed on computers from, PC-compatible manufacturers including Zenith Data, Systems., Windows 3 introduced the ability to run MS-DOS, programmes in windows, which brought multitasking to, legacy programmes, and supported 256 colours bringing, a more modern, colourful look to the interface., More important - at least to the sum total of human time, wasted - it introduced the card-moving timesink (and, mouse use trainer) Solitaire., , Windows 1, , Windows 3.1, , The first version of Windows, , Windows 3.1 with Minesweeper., , This is where it all started for Windows. The original, Windows 1 was released in November 1985 and was, Microsoft's first true attempt at a graphical user interface, in 16-bit., , Windows 1 and 2 both had point release updates, but, Windows 3.1 released in 1992 is notable because it, introduced TrueType fonts making Windows a viable, publishing platform for the first time., , Development was spearheaded by Microsoft founder Bill, Gates and ran on top of MS-DOS, which relied on, command-line input., , Minesweeper also made its first appearance. Windows, 3.1 required 1MB of RAM to run and allowed supported, MS-DOS programs to be controlled with a mouse for, the first time. Windows 3.1 was also the first Windows, to be distributed on a CD-ROM, although once installed, on a hard drive it only took up 10 to 15MB (a CD can, typically store up to 700MB)., , It was notable because it relied heavily on use of a mouse, before the mouse was a common computer input device., To help users become familiar with this odd input system,, Microsoft included a game, Reversi (visible in the, screenshot) that relied on mouse control, not the, keyboard, to get people used to moving the mouse, around and clicking onscreen elements., Windows 2, Windows 2 with overlapping windows., Two years after the release of Windows 1, Microsoft's, Windows 2 replaced it in December 1987. The big, innovation for Windows 2 was that windows could overlap, each other, and it also introduced the ability to minimise, or maximise windows instead of "iconising" or "zooming"., The control panel, where various system settings and, configuration options were collected together in one, place, was introduced in Windows 2 and survives to this, day., Microsoft Word and Excel also made their first, appearances running on Windows 2., Windows 3, Windows 3.0 got colourful., The first Windows that required a hard drive launched in, 1990. Windows 3 was the first version to see more, widespread success and be considered a challenger to, , Windows 95, Windows 95: oh hello Start menu., As the name implies, Windows 95 arrived in August 1995, and with it brought the first ever Start button and Start., It also introduced the concept of "plug and play" - connect, a peripheral and the operating system finds the, appropriate drivers for it and makes it work. That was, the idea; it didn't always work in practice., Windows 95 also introduced a 32-bit environment, the, task bar and focused on multitasking. MS-DOS still, played an important role for Windows 95, which required, it to run some programmes and elements., Internet Explorer also made its debut on Windows 95, but, was not installed by default requiring the Windows 95 Plus!, pack. Later revisions of Windows 95 included IE by default,, as Netscape Navigator and NCSA Mosaic were popular at, the time., Windows 98, Windows 98, the last great DOS-based Windows., Released in June 1998, Windows 98 built on Windows, 95 and brought with it IE 4, Outlook Express, Windows, , Copyright @ NIMI Not to be Republished, , 25
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Address Book, Microsoft Chat and NetShow Player, which, was replaced by Windows Media Player 6.2 in Windows, 98 Second Edition in 1999., , CD burning, autoplay from CDs and other media, plus, various automated update and recovery tools, that unlike, Windows ME actually worked., , Windows 98 introduced the back and forward navigation, buttons and the address bar in Windows Explorer, among, other things. One of the biggest changes was the, introduction of the Windows Driver Model for computer, components and accessories - one driver to support all, future versions of Windows., , Windows XP was the longest running Microsoft operating, system, seeing three major updates and support up until, April 2014 - 13 years from its original release date., Windows XP was still used on an estimated 430m PCs, when it was discontinued., , USB support was much improved in Windows 98 and, led to its widespread adoption, including USB hubs and, USB mice., Windows ME, Windows ME was one to skip., Considered a low point in the Windows series by many at least, until they saw Windows Vista - Windows, Millennium Edition was the last Windows to be based on, MS-DOS, and the last in the Windows 9x line., Released in September 2000, it was the consumer-aimed, operating system twined with Windows 2000 aimed at, the enterprise market. It introduced some important, concepts to consumers, including more automated, system recovery tools., IE 5.5, Windows Media Player 7 and Windows Movie, Maker all made their appearance for the first time., Autocomplete also appeared in Windows Explorer, but, the operating system was notorious for being buggy,, failing to install properly and being generally poor., Windows 2000, Windows 2000 was ME's enterprise twin., The enterprise twin of ME, Windows 2000 was released, in February 2000 and was based on Microsoft's businessorientated system Windows NT and later became the, basis for Windows XP., Microsoft's automatic updating played an important role, in Windows 2000 and became the first Windows to, support hibernation., Windows XP, Windows XP still survives to this day., Arguably one of the best Windows versions, Windows, XP was released in October 2001 and brought Microsoft's, enterprise line and consumer line of operating systems, under one roof., Advertisement, It was based on Windows NT like Windows 2000, but, brought the consumer-friendly elements from Windows, ME. The Start menu and task bar got a visual overhaul,, bringing the familiar green Start button, blue task bar, and vista wallpaper, along with various shadow and other, visual effects., ClearType, which was designed to make text easier to, read on LCD screens, was introduced, as were built-in, 26, , Its biggest problem was security: though it had a firewall, built in, it was turned off by default. Windows XP's huge, popularity turned out to be a boon for hackers and, criminals, who exploited its flaws, especially in Internet, Explorer, mercilessly - leading Bill Gates to initiate a, "Trustworthy Computing" initiative and the subsequent, issuance of to Service Pack updates that hardened XP, against attack substantially., Windows Vista, Windows Vista, arguably worse than Windows ME., Windows XP stayed the course for close to six years, before being replaced by Windows Vista in January 2007., Vista updated the look and feel of Windows with more, focus on transparent elements, search and security. Its, development, under the codename "Longhorn", was, troubled, with ambitious elements abandoned in order, to get it into production., Advertisement, It was buggy, burdened the user with hundreds of requests, for app permissions under "User Account Control" - the, outcome of the Trustworthy Computing initiative which, now meant that users had to approve or disapprove, attempts by programs to make various changes., The problem with UAC was that it led to complacency,, with people clicking "yes" to almost anything - taking, security back to the pre-UAC state. It also ran slowly on, older computers despite them being deemed as "Vista, Ready" - a labelling that saw it sued because not all, versions of Vista could run on PCs with that label., PC gamers saw a boost from Vista's inclusion of, Microsoft's DirectX 10 technology., Windows Media Player 11 and IE 7 debuted, along with, Windows Defender an anti-spyware programme. Vista, also included speech recognition, Windows DVD Maker, and Photo Gallery, as well as being the first Windows to, be distributed on DVD. Later a version of Windows Vista, without Windows Media Player was created in response, to anti-trust investigations., Windows 7, Windows 7 was everything Windows Vista should, have been., Considered by many as what Windows Vista should have, been, Windows 7 was first released in October 2009. It, was intended to fix all the problems and criticism faced, by Vista, with slight tweaks to its appearance and a, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished
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concentration on user-friendly features and less "dialogue, box overload"., It was faster, more stable and easier to use, becoming, the operating system most users and business would, upgrade to from Windows XP, forgoing Vista entirely., Handwriting recognition debuted in 7, as did the ability, to "snap" windows to the tops or sides of the screen,, allowing faster more automatic window resizing., , Windows 8.1, Windows 8.1 and the great reappearance of the Start, button., A free point release to Windows 8 introduced in October, 2013, Windows 8.1 marked a shift towards yearly, software updates from Microsoft and included the first, step in Microsoft's U-turn around its new visual interface., , Windows 7 saw Microsoft hit in Europe with antitrust, investigations over the pre-installing of IE, which led to, a browser ballot screen being shown to new users, allowing them to choose, which browser to install on first, boot., , Windows 8.1 re-introduced the Start button, which, brought up the Start screen from the desktop view of, Windows 8.1. Users could also choose to boot directly, into the desktop of Windows 8.1, which was more suitable, for those using a desktop computer with a mouse and, keyboard than the touch-focused Start screen., , Windows 8, , Windows 10, , Windows 8 focused more on touch than a keyboard, and mouse., , With Windows 10, Microsoft is trying to keep some of, the touch and tablet features it created for Windows 8,, combine them with the familiar Start menu and desktop,, and run it all on top of an improved operating system, with more security, a new browser, the Cortana assistant,, its own version of Office for on-the-go editing and plenty, of new features intended to make life simpler., , Released in October 2012, Windows 8 was Microsoft's, most radical overhaul of the Windows interface, ditching, the Start button and Start menu in favour of a more touchfriendly Start screen., Advertisement, The new tiled interface saw programme icons and live, tiles, which displayed at-a-glance information normally, associated with "widgets", replace the lists of, programmes and icons. A desktop was still included,, which resembled Windows 7., , Of course, that also means it's very different to use,, whether you come from Windows 7, Windows 8 or, Windows XP. You have to look in a new place even to, turn your PC off., , Windows 8 was faster than previous versions of Windows, and included support for the new, much faster USB 3.0, devices., , On top of that, Windows 10 is more than just a PC, operating system; it's also what will run on Windows, phones - and on small tablets as well, because a 6-inch, phone and a 7-inch tablet aren't such very different, devices., , The Windows Store, which offers universal Windows, apps that run in a full-screen mode only, was introduced., Programs could still be installed from third-parties like, other iterations of Windows, but they could only access, the traditional desktop interface of Windows., , Microsoft is expecting people to put Windows 10 on a, billion devices (which ought to encourage more app, developers to at least take a look at building their apps, for Windows phones and tablets, as well as for Xbox, One and HoloLens)., , The radical overhaul was not welcomed by many., Microsoft attempted to tread a fine line between, touchscreen support and desktop users, but ultimately, desktop users wanting to control Windows with a, traditional mouse and keyboard and not a touchscreen, felt Windows 8 was a step back., , The Start menu evolves, , There were also too few touchscreens in use, or on offer,, to make its touch-oriented interface useful or even, necessary - despite the parallel rise of tablets such as, the iPad, and smartphones, which had begun outselling, PCs by the end of 2010., , The full-screen Start screen of Windows 8 is back to, being a Start menu in Windows 10 that tries to combine, the best of both options. A scrolling Start menu that's, restricted to a single column, with jump lists and flyout, menus for extra options, divided into frequently used, and recently installed programs, with the option to switch, to a scrolling view of all the applications, sorted, alphabetically., Fig 1, , It looked and felt like Windows 8, but could not run, traditional Windows applications, instead solely relying, on the Windows Store for third-party apps., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13701, , Windows RT, which runs on ARM-based processors, traditionally found in smartphones and non-PC tablets,, was introduced at the same time as Windows 8 with the, Microsoft Surface tablet., , 27
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But also get an extra pane ,where can pin Windows 8style tiles, complete with 'rotating 3D cube' animations of, live tiles. drag the Start menu to be a larger size or even, set it to be full screen., Desktop Background, Another component of the Desktop is the Background., This is simply an image that appears at the back of the, screen. Most computers come with a pre-selected, background, but change it to any image., , alternative is to use the File Explorer by clicking on the, Folder icon on the Taskbar., In the File Explorer window, browse all the folders and, documents., Fig 4, , To change the background, follow these steps:, 1. Right-click on the background and choose, "Personalize", 2. From the Personalization window, choose from a series, of pre-selected pictures or browse for your own., After choosing a picture, the Background will change, automatically., Copa 13704, , Start Menu, If looking for a specific application, open the Start Menu, and click "All Applications". This will open an alphabetical, , Fig 2, , Virtual Desktops, One of the new features of Windows 10 is the addition of, Virtual Desktops. This allows you to have multiple desktop, screens where to keep open windows organized., , Copa 13705, , Copa 13702, , Fig 5, , list of all the applications installed on computer., , To add a virtual desktop, follow these steps:, , Fig 3, , File Explorer, If you are looking for a specific document, another, , 28, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13706, , Copa 13703, , Fig 6
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1. Click Task View on the Taskbar, 2. Click the "New desktop" option on the lower-right corner., You can access or delete the new Desktop by clicking, Task View again., Cortana helps as with search and control, Cortana, the Windows Phone assistant, shows up in, , Fig 7, , If Cortana isn't active, can turn it on by typing "Cortana" in, the Taskbar search to access the Cortana settings, or, just clicking the "Gear" icon on the left-side of the menu., After activating Cortana, it will start gathering information, about to personalize the experience., Task switcher, Most Windows users don't know the Alt-Tab keyboard, , Copa 13707, , Fig 10, , Windows 10 as a search pane on the taskbar, which can, also trigger by saying 'Hey Cortana' - and when start, searching the Start menu., Fig 8, , combination to see and switch between all running apps,, so as well as having a redesigned task switcher with bigger, , Copa 13708, , Fig 11, , That gets theapps have installed, documents access to,, apps could install from the Store, search results from the, web and a range of other information - including from apps, and services that integrate with Cortana., Activating Cortana, , Copa 137011, , Fig 9, , thumbnails, Windows 10 also puts a task view icon in the, taskbar to help them find it., Copa 13709, , TASKBAR, The Windows 10 taskbar sits at the bottom of the screen, giving the user access to the Start Menu, as well as the, icons of frequently used applications. On the right-side,, the Taskbar features the Notification Area which informs, the user of different things like the state of the Internet, connection or the charge of the laptop battery., The icons in the middle of the Taskbar are "pinned", applications, which is a way to have a quick access to, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , 29
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applications you use frequently. "Pinned" applications, will stay in the Taskbar until you "unpin" them., , Copa 1137012, , Fig 12, , Taskbar. It shows different types of notifications from your, computer like your Internet connection, or the volume level., At first, the Notification Area shows a limited amount of, icons. But you can click the upward arrow on its left-side, to see other icons as well., Snap Assist, Because all the apps and programs run in windows on the, Fig 15, , Pin an Application to the Taskbar, Copa 137015, , Step 1: Search for the application you want to pin in the, Start Menu., Step 2: Right-click on the application., Step 3: Select "More" option at the top of the menu., Step 4: Select the "Pin to taskbar" option., Unpin an Application from the Taskbar, To "unpin" it, just right-click the icon in the Taskbar and, select "Unpin from taskbar". You can "pin" it back again, , desktop, instead of modern apps from the Store being in, their own space, and can no longer drag across the left, edge of the screen to bring another app on screen and get, a split view. Instead, drag windows into the corners of the, screen to get the familiar Snap view., Now use all four corners of the screen if want each window, to take up a quarter of the screen instead of half, and the, space that isn't filled by the window you just dragged shows, thumbnails of your other windows to make it easier to, snap the next one into place., , Fig 13, , Action Center, , Copa 137013, , If we used Windows Phone 8.1 (or Android and/or iOS),, we used to a notification centre can drag down from the, top of the screen., , any time you want., Notification Area, The Notification Area is located at the right side of the, , Fig 14, , The command prompt, Those of us that use the command prompt have been, stuck with pretty much the same experience since the, 1990s, but in Windows 10 can finally resize the, command prompt window and use familiar keyboard, shortcuts to copy and paste at the command prompt., It's far from ground-breaking but it's a very welcome, improvement after years of frustration., FILE EXPLORER, , Copa 137014, , 30, , Windows 10 puts that on the right of the screen, where, the charms bar was in Windows 8, with notifications from, various apps at the top and the choice of various settings, buttons at the bottom for quick access., , File Explorer is the file management application used, by Windows operating systems to browse folders and, files. It provides a graphical interface for the user to, navigate and access the files stored in the computer., The main way to access the File Explorer is by clicking, the folder icon in the Taskbar. After clicking the icon, the, File Explorer window will open., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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Multiple desktops, , Fig 15, , User need to arrange a lot of windows and don't have, multiple monitors, user can put them on multiple virtual, desktops. And can use Alt-Tab to move between apps, as usual and then Windows-Ctrl and the left and right, arrow keys to move between desktops., , Copa 137015, , Schedule restarts, , The initial File Explorer window is comprised of the following, sections:, 1. The File Explorer ribbon, which resembles the ribbon, featured in Microsoft Office. The ribbon contains buttons, for common tasks to perform with your files and folders., 2. The Navigation Pane gives you access to your, libraries of documents and pictures, as well as your, storage devices. It also features frequently used folders, and network devices., 3. The Frequent folders section on the right features, the folders you've worked with recently to allow for quick, access to them., 4. The Recent files section in the lower part of the, window features files and documents that you've opened, recently., The new Edge browser, To catch up with fast-moving browsers like Chrome and, Firefox, Microsoft took its browser back to basics, ripping, out years of code that didn't fit with web standards and, making a lean, fast browser., It's a work in progress - it won't get support for things like, ad-blocking extensions until a while after Windows 10, launches - but can do plenty of neat things here. For, example, and can scribble notes on a web page to send, to a friend and Edge has Cortana built in to pull useful, information out of web pages, like the phone number of, a restaurant, or the opening hours., Sites like Medium that didn't work properly with IE should, look better and have more features in Edge., , No more having Windows announce that you have fifteen, minutes to get everything done before it restarts to apply, an update. Instead of leaving Windows 10 to decide when, to do that, if there's an update that will need a restart, and can have Windows ask when you want to schedule, that for., user can only do that once the update has been, downloaded. If user want to have certain times off-limits, for restarts, they will need the features in Windows, Update for Business (for Windows 10 Pro and Enterprise), which lets block restarts so they don't happen in working, hours, or on certain dates., Universal apps - including Office, Windows 10 gets a new Windows Store, where download, desktop programs as well as modern Windows apps., Many of those apps will be universal apps that are the, same code on a PC, a Windows phone, an Xbox One, and even on HoloLens, with the interface changing to, suit the different screen sizes. The Office for Windows, apps like Word and Excel are universal apps, as are the, Outlook Mail and Calendar apps., Settings and control panel, The Windows 8 Settings app has taken over many more, of the settings that used to be in Control Panel, and it, has a Control Panel-style interface with icons to navigate, with. But the old Control Panel interface is still there, for, settings that aren't in the new Settings app (or if you're, just used to finding things there)., Windows 10 - Keyboard ShortcutsUTS, Like most Windows applications, there are several, keyboard shortcuts you can use to make it easier or faster, for some to perform certain tasks., Most of the new Windows shortcuts use the Windows, key () combined with other keys to perform several, actions. The following are some of the most common or, useful shortcuts used in Windows 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished, , 31
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Keyboard Shortcuts for Navigating Windows 10, Press This, , 32, , To Do This, , Windows Logo, , Toggle the Start menu, , Windows Logo+A, , Open the Notifications pane, , Windows Logo+B, , Activate the notification area's Show Hidden Icons arrow (press Enter to display, the hidden icons), , Windows Logo+C, , Open Cortana for voice commands, , Windows Logo+D, , Minimize all open windows to display the desktop, , Windows Logo+E, , Run File Explorer, , Windows Logo+F, , Display the Start menu and activate the Search box, , Windows Logo+H, , Display the Share pane, , Windows Logo+I, , Run the Settings app, , Windows Logo+K, , Display the Devices pane, , Windows Logo+L, , Lock your computer, , Windows Logo+M, , Minimize all windows, , Windows Logo+O, , Turn the tablet orientation lock on and off, , Windows Logo+P, , Display the Project pane to configure a second display, , Windows Logo+Q, , Open Cortana for voice commands, , Windows Logo+R, , Open the Run dialog box, , Windows Logo+S, , Open Cortana for keyboard commands, , Windows Logo+T, , Activate the taskbar icons (use the arrow keys to navigate the icons), , Windows Logo+U, , Open the Ease of Access Center, , Windows Logo+W, , Activate the Search box, , Windows Logo+X, , Display a menu of Windows tools and utilities, , Windows Logo+Z, , Display an app's commands (although this works in only some Modern apps), , Windows Logo+=, , Open Magnifier and zoom in, , Windows Logo+-, , Zoom out (if already zoomed in using Magnifier), , Windows Logo+,, , Temporarily display the desktop, , Windows Logo+Enter, , Open Narrator, , Windows Logo+Left, , Snap the current app to the left side of the screen, , Windows Logo+Right, , Snap the current app to the right side of the screen, , Windows Logo+Up, , Restore a minimized app; maximize a restored app, , Windows Logo+Down, , Restore a maximized app; minimize a restored app, , Windows Logo+PgUp, , Move the current app to the left monitor, , Windows Logo+PgDn, , Move the current app to the right monitor, , Windows Logo+PrtSc, , Capture the current screen and save it to the Pictures folder, , Windows Logo+Ctrl+D, , Create a virtual desktop, , Windows Logo+Ctrl+Right, , Switch to the next virtual desktop, , Windows Logo+Ctrl+Left, , Switch to the previous virtual desktop, , Windows Logo+Ctrl+F4, , Close the current virtual desktop, , Windows Logo+Tab, , Open Task View, which displays thumbnails for each running app as well as, the available virtual desktops, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Windows Opeating System, , Related Theory for Exercise 1.3.12, , Handling printers, Objectives : At the end of this lesson you shall be able to, • explain about typewriter, • explain about printer, • explain types and cost of printers, • explain programming languages for printers, • explain how to locate printer driver files., Typewriter, A typewriter is a mechanical or electromechanical device, with keys that, when pressed, cause characters to be, printed on a medium, usually paper as on Fig 1. Typically, one character is printed per keypress, and the machine, prints the characters by making ink impressions of type, elements similar to the sorts used in movable type, letterpress printing., , Fig 2, , Fig 1, , Fig 3, , After their invention in the 1860s, typewriters quickly, became indispensable tools for practically all writing other, than personal correspondence. They were widely used, by professional writers, in offices, and for business, correspondence in private homes. By the end of the, 1980s, word processors and personal computers had, largely displaced typewriters in most of these uses., Computer printer, A printer is a piece of hardware for a computer as on, Fig 2. It is a device that must be connected to a computer, which allows a user to print items on paper, such as letters, and pictures. It can also work with digital cameras to, print directly without the use of a computer., Types of printers, Today, the following types of printers are in regular use:, Daisy wheel printing is an impact printing technology, invented in 1969 by David S. Lee atDiablo Data Systems, as on Fig 3. It uses interchangeable pre-formed type, elements, each with typically 96 glyphs, to generate highquality output comparable to premium typewriters such, , as theIBM Selectric, but two to three times faster. Daisy, wheel printing was used in electronic typewriters, word, processors and computers from 1972. According to, Webster's, the daisy wheel is so named because of its, resemblance to the daisy flower., , Copyright @ NIMI Not to be Republished, , 33
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Dot-matrix printers are now almost extinct. They used a, ribbon and made a lot of noise. There were models with, 9 pins and models with 24 pins as on Fig 4. A dot matrix, printer or impact matrix printer is a type of computer, printer with a print head that runs back and forth, or in an, up and down motion, on the page and prints by impact,, striking an ink-soaked cloth ribbon against the paper,, much like the print mechanism on a typewriter., , Fig 6, , Fig 4, , such wide-format printers as "plotters," even though they, technically are not., , Inkjet printing is a type of computer printing that creates, a digital image by propelling droplets of ink onto paper, as on Fig 5. Inkjet printers are the most commonly used, type of printer, and range from small inexpensive, consumer models to very large professional machines, that can cost tens of thousands of dollars., , Pen plotters print by moving a pen or other instrument, across the surface of a piece of paper. This means that, plotters are restricted to line art, rather than raster, graphics as with other printers. Pen plotters can draw, complex line art, including text, but do so slowly because, of the mechanical movement of the pens. They are often, incapable of efficiently creating a solid region of color,, but can hatchan area by drawing a number of close,, regular lines., Laser printing is a digital printing process that rapidly, produces high quality text and graphics on plain paper., As with digital photocopiers and multifunction printers, (MFPs), laser printers employ a xerographic printing, process, but differ from analog photocopiers in that the, image is produced by the direct scanning of a laser beam, across the printer's photoreceptor., , Fig 5, , A laser beam projects an image of the page to be printed, onto an electrically charged rotating drum coated with, selenium or, more common in modern printers, organic, photoconductors. Photoconductivity allows charge to leak, away from the areas exposed to light., , The concept of inkjet printing originated in the 20th, century, and the technology was first extensively, developed in the early 1950s. Starting in the late 1970s, inkjet printers that could reproduce digital images, generated by computers were developed, mainly by, Epson,Hewlett-Packard (HP), and Canon. In the, worldwide consumer market, four manufacturers account, for the majority of inkjet printer sales: Canon, HP, Epson,, and Lexmark, a 1991 spin-off from IBM., The plotter is a computer printer for printing vector, graphics as on Fig 6. In the past, plotters were used in, applications such as computer-aided design, though they, have generally been replaced with wide-format, conventional printers. It is now commonplace to refer to, 34, , Dry ink (toner) particles are then electro statically picked, up by the drum's charged areas, which have not been, exposed to light. The drum then prints the image onto, paper by direct contact and heat, which fuses the ink to, the paper., Cost of printers, There are different costs with a printer. Printers that are, more expensive to buy will usually be less expensive in, the consumables (the ink, toner, or ribbon used by the, printer). Therefore, laser printers are often more, expensive to buy than inkjet printers, but are not, expensive to use over a long period of time., Inkjet printers on the other hand have a higher cost of, consumables because the ink tanks they use are more, expensive than the toner for a laser printer., Laser printers that can print in color are usually more, expensive than those that only print in black and white., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished
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Other options, like being able to print on both sides of a, sheet of paper, to automatically sort the output, or to, staple the output will also make a printer more expensive., , Fig 7, , Common programming languages for printers, include:, ESC/P, , •, , Postscript, , •, , PCL, , •, , GDI, , •, , HPGL and HPGL/2, , •, , PDF, , Prominent features of a scanner include:, , •, , VPS, , •, , Reliability - Unlike certain forms of data transmission,, scanning involves only transfer of hard images to, digital forms. The role of the end-user is limited in, case of scanning. And as they are not dependent on, two-way communication, they can also help in storing, important information or transmitting important, information., , •, , Efficiency - Modern scanners are built for efficiency, and speed. And it comes with ease of use as well as, convenience., , •, , Quality - Scanning ensures the best resolution, possible for digital images. Compared to fax, machines, which may find it difficult to reproduce the, accurate details, scanners can reproduce images with, high resolution and precisions. They are quite useful, for photography and engineering arenas., , •, , Cost saving - One of the biggest advantage of, scanning is the replacement of physical files/forms, with digital ones. Along with saving physical space,, which has to be used for storage, there are also, environmental benefits by using scanner., , Copa 110107, , •, , How to Locate Printer Driver Files, Printers can be connected to a computer by a variety of, wired and wireless methods, but all printers require, drivers to be installed on a computer. The printer drivers, are small programs that help communicate information, from the operating system to the printer., Driver errors can make the printer unusable. Using the, Windows device manager, you can look up details about, the drivers as well as pinpoint their physical location on, your hard drive., Scanner, A scanner is an electronic device which can capture, images from physical items and convert them into digital, formats, which in turn can be stored in a computer, and, viewed or modified using software applications., Different types of scanners are available with different, resolutions. In the world of electronic data transmission,, scanning is considered to be the most cost-effective and, reliable way of transmitting images., The basic principle of a scanner is to analyze an image, and reproduce it to a digital one using the optical, character recognition techniques., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished, , 35
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IT & ITES, Related Theory for Exercise 1.4.13, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., The Basic Input/Output System (BIOS), also known as, System BIOS, ROM BIOS or PC BIOS is a generally, accepted standard defining a firmware interface., , •, , The fundamental purpose of the BIOS is to initialize and, test the system hardware components and load an, operating system from a mass memory device. The BIOS, is special software that interfaces the major hardware, components of the computer with the operating system., It is usually stored on a Flash memory chip on the, motherboard, but sometimes the chip is another type of, ROM. The BIOS is a firmware (software instructions, permanently recorded on a chip located on your, motherboard). (Refer Fig.1)., , The first thing the BIOS will do is check the information, stored in a tiny (64 bytes) amount of RAM located on a, complementary metal oxide semiconductor (CMOS), chip. The CMOS Setup provides detailed information, particular to your system and can be altered as your, system changes. The BIOS uses this information to, modify or supplement its default programming as, needed., , Copa 181301, , Fig 1, , Functions of BIOS, The BIOS software has a number of different roles, but, its most important role is to load the operating system., The BIOS checks and initializes the PC hardware each, time the system powers up or restarts before handing, over control to the operating system. Some of the other, common tasks that the BIOS performs include:, •, , A power-on self-test (POST) for all of the different, hardware components in the system to make sure, everything is working properly, , •, , Activating other BIOS chips on different cards installed, in the computer - For example the graphics cards often, have their own BIOS chips., , •, , Providing a set of low-level routines that the operating, system uses to interface to different hardware, devices. They manage things like the keyboard, the, screen, and the ports, especially when the computer, is booting., , 36, , Managing a collection of settings for the hard disks,, clock, etc., , CMOS Setup, , Configuring BIOS, The BIOS checks the CMOS Setup for custom settings., To change the CMOS settings we need to enter the, CMOS setup. To enter the CMOS Setup, a certain key, or combination of keys must be pressed during the initial, startup sequence. Most systems use "Esc," "Del," "F1,", "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. There is, usually a line of text at the bottom of the display that, tells "Press ___ to Enter Setup.", The BIOS setup shows a set of text screens with a, number of options. Some of these are standard, while, others vary according to the BIOS manufacturer., Common options include:, •, , System Time/Date - Set the system time and date, , •, , Boot Sequence - The order that BIOS will try to load, the operating system, , •, , Plug and Play - A standard for auto-detecting connected, devices; should be set to "Yes" if your computer and, operating system both support it, , •, , Mouse/Keyboard - "Enable Num Lock," "Enable the, Keyboard," "Auto-Detect Mouse"..., , •, , Drive Configuration - Configure hard drives, CD-ROM, and floppy drives, , •, , Memory - Direct the BIOS to shadow to a specific, memory address, , •, , Security - Set a password for accessing the computer, , •, , Power Management - Select whether to use power, management, as well as set the amount of time for, "standby" and "suspend", , Copyright @ NIMI Not to be Republished
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•, , Exit - Save your changes, discard your changes or, restore default settings., , The BIOS uses CMOS technology to save any changes, made to the computer's settings. With this technology, a, small lithium or Ni-Cad battery can supply enough power, to keep the data for years. Major BIOS manufacturers, include American Megatrends Inc. (AMI), Phoenix, Technologies, Winbond etc. A typical BIOS screenshot, is shown in fig. given below.(Refer Fig.2), Fig 2, , •, , Use of multi-boot setups, which allow users to have, more than one operating system on a single computer., For example, one could install Linux and Microsoft, Windows or other operating systems on different, partitions of the same HDD and have a choice of, booting into any operating system at power-up., , •, , Protecting or isolating files, to make it easier to recover, a corrupted file system or operating system installation., If one partition is corrupted, other file systems may not, be affected., , •, , Raising overall computer performance on systems, where smaller file systems are more efficient., , •, , Partitioning for significantly less than the full size, available can reduce the time for diagnostic tools such, as checkdisk to run., , Copa 181302, , Formatting, , Installing the Windows operating System, A hard disk needs to be partitioned (though not, mandatory) and formatted before you can store data, on it., Partitioning, A partition, sometimes also called a volume, is an area, on a hard disk that can be formatted with a file system, and identified with a letter of the alphabet. For example,, drive C on most Windows computers is a partition. the, first three partitions you create are primary partitions., These can be used to start an operating system. If you, want to create more than three partitions, the fourth, partition is created as an extended partition., An extended partition is a container that can hold one or, more logical drives. Logical drives function like primary, partitions except that they cannot be used to start an, operating system., Many computers are partitioned as a single partition that, equals the size of the hard disk. Partitioning a hard disk, into several smaller partitions is not required, but it can, be useful for organizing data on your hard disk., Creating more than one partition has the following, advantages:, •, , Separation of the operating system (OS) and program, files from user files., , •, , Having a separate area for operating system virtual, memory swapping/paging., , •, , Keeping frequently used programs and data near each, other., , Disk formatting is the process of preparing a data storage, device such as a hard disk drive, solid-state drive or, USB flash drive for initial use. It is the act of creating a, file system on a volume, so that the operating system, can store and retrieve data on that volume., Formatting of a disk is of two categories:, 1 Low-level formatting (i.e., closest to the hardware), marks the surfaces of the disks with markers, indicating the start of a recording block. It also, provides information about block checks done for, future use by the disk controller to read or write data., This is intended to be the permanent foundation of, the disk, and is often completed at the factory. A hard, disk needs to be partitioned and formatted before you, can store data on it, 2 High-level formatting creates the file system format, within a disk partition or a logical volume. This, formatting includes the data structures used by the, OS to identify the logical drive or partition's contents., This may occur during operating system installation,, or when adding a new disk., Installing the Windows operating System, The three basic types of windows installation procedures, are as follows:, •, , Install on a brand new disk or computer system, , •, , Erase the disk, format it, and install., , •, , Install into a new directory for dual-booting, , For the first two methods, it must be ensured that the, computer can boot from a DVD or any other removable, drive. To do this the drive boot order needs to be changed, in the BIOS. The latest Windows DVDs are bootable, and run the Setup program automatically. Then the, installation can be done by following the procedure step, by step as indicated on the subsequent screens as in, trade practicals., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.13, , Copyright @ NIMI Not to be Republished, , 37
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IT & ITES, Related Theory for Exercise 1.4.14 & 1.4.15, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., Format a hard drive, , Format hard drive partitions, It's important to understand about partitions before getting, started. A hard drive can be divided up into smaller, sections, called partitions. It's possible to format one, partition while leaving the others untouched., , Fig 1, , If it isrequired to format the entire hard drive and use the, entire capacity in one block, delete the partition, information., Format a hard drive from the BIOS?, , Copa 110101, , Many people ask how to format a hard disk from BIOS., The short answer is no., , There are many reasons why it is required to format a, hard drive, such as to install Windows fresh, to get rid of, a virus or malware or simply because a pc is refreshed, or cleaned up on selling., , If it is required to format a disk and you can't do it from, within Windows, create a bootable CD, DVD or USB flash, drive and run a free third-party formatting tool., One option is Darik's Boot and Nuke (DBAN), which is, free for personal use. This program will totally erase and, format your hard disk, allowing for a clean install of a, new OS, but the process cannot be undone., Fig 2, , The process can be different depending on whether it's, an only hard drive and whether there is a spare PC or, not., , Copa 110102, , It cannot be formatted, the hard drive on which Windows, is running. In order to do this, it is in need to boot the PC, from a Windows installation disc, a USB flash drive or, another bootable disc., Format a disk?, Formatting is the process of deleting all the data on the, hard drive, but beware of 'Quick Format' which leaves, all data in place and makes the drive appear to be empty., A quick format is ok if there is a brand new hard drive, or, need to reinstall Windows, but not if its disposing of the, disk or giving it to someone else., , DBAN is supposedly only able to create a bootable CD/, DVD-R, but if don't have any blank discs or a burner,, there is a workaround available in the form of a separate, third-party program., , A word of warning: make sure to have successfully, backed up any photos, videos, music and other, documents from the drive before formatting it. Although, deleted files can be recovered in some situations,, prevention is always better than cure., , Universal USB Installer will quickly and easily convert, the DBAN ISO image downloaded to run from a bootable, USB. Simply insert a blank USB flash drive, run the, Universal USB Installer setup program, and follow the, prompts., It will ask to scroll through and pick the Linux Distribution, want to install to USB (in this case, the latest version of, DBAN), followed by its location on the computer and the, letter of the USB drive like to install it to., , 38, , Copyright @ NIMI Not to be Republished
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Once that information is complete, click create., , Copa 191503, , To boot from this USB drive rather than usual boot device, (in most cases, this would be the hard drive), it have to, be changed some settings in the BIOS., In the BIOS, navigate to the boot order settings, and, change the primary boot device to the USB drive (it, shouldn't need to be plugged in to make this selection)., After saved the settings and exited the BIOS, insert the, bootable USB, restart the computer., , Copa 191505, , Fig 5, , Fig 3, , By default Quick Format is checked, and choose the file, system and allocation unit size as well as changing the, volume label (the drive's name). Typically, leave all, settings unchanged and click the Start button. In under a, minute the hard drive will be formatted., , Fig 6, , Copa 191504, , Fig 4, , It will treat the USB as another drive so to avoid, inadvertently wiping that as well, remove it after booted, into DBAN., Quick format a hard drive?, Yes, but don't use this method if want the data to be, permanently erased. A quick format doesn't delete the, data but instead erases only the pointers to the files., Windows Vista, 7, 8 and 10 have a built-in Disk, Management tool (see below), but the fastest way to, format a hard drive is to click the Start button, then, Computer and right-click on the hard drive to wipe. It, can't be formatted the drive on which Windows is installed, for obvious reasons., , Copa 191506, , The PC should automatically boot the DBAN software,, which will guide through the process of erasing the hard, drive, with options for different levels of data-wiping., , Choose NTFS as the file system if it isn't already selected, for Windows Vista, 7, 8 or 10 and ensure the Allocation, Unit Size is set to 'Default Allocation Size'., Using the Disk Management tool, Type diskmgmt.msc or Disk Management into the search, box in Vista, 7, 8 or 10 and then click on only result that, appears in the menu above, with the same name., This is the easiest way to launch Disk Management, but, also find it in the Control Panel if search for 'disk' and, select the 'Create and format hard disk partitions'., Disk Management isn't as powerful as a standalone, partition management tool, but it is still capable of, formatting data., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 39
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If select a size for the partition that's smaller than the total, capacity of the drive, say 500B on a 1TB drive, end up, with some unallocated space on the drive which can format, by repeating the process just completed., , Fig 7, , change partition size, Disk Management can be used to expand or shrink a, partition. Simply right-click on one and choose the, appropriate option from the menu that appears. If, shrinking, the partition will be checked to find out how, much empty space it contains., , If it is to install a new (additional) hard drive in a PC, it, might be a thing to wonder why it doesn't appear in Windows, Explorer. The reason is because it needs to be initialised, and formatted -which can be done in Disk Management., When the tool loads, it will analyse all of the computer's, drives and will prompt to initialise a new disk that it finds., , Fig 8, , Copa 191509, , Copa 191507, , Fig 9, , It's a little confusing as the numbers are displayed in MB, rather than GB, but it can be adjusted the amount of, space to shrink and the 'Total size after shrink' will be, updated, alsocan't shrink a partition beyond the point, where files are located - it may be able to free up space, by defragmenting the drive first., Conversely it can only expand a partition if there is, unused space on the drive. If not, the option will be greyed, out., , Copa 191508, , Resetting Windows, If PC is having problems and the user don't wish to lose, the personal files by wiping the hard drive, then it might, want to refresh or reset the PC which can be done in, Windows 8 and 10., If user looking to keep your personal files and settings,, but want to have a fresh Windows install, itsall want to, refresh the PC., , If the disk is larger than 2TB, opt for GPT (GUID Partition, Table). This setting also lets to create more than four, partitions., , Do note that a refresh will remove all programs and apps, installed on the machine, but will keep the Windowsdefault programs intact., , If don't see a prompt, look in the list of drives and see, one that says 'Not Initialized'. Right-click on it and choose, Initialize Disk., , A reset reinstalls Windows and deletes all files, settings, and programs, it is suggested performing this if have, previously backed up all the files and don't mind, transferring user's personal files., , Once that's done, right-click in the hatched Unallocated, space and choose New Simple Volume…, Follow the instructions, choosing how big to want the, partition to be (in MB - 1024MB = 1GB), and which drive, letter to assign (one will be chosen, but can opt to change, it if desired)., , 40, , Windows 10 has a slightly different approach and might, confuse those coming from Windows 8. Microsoft, removed the refresh option and has instead combined, the refresh and reset options into one setting., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished
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Copa 1915010, , Fig 10, , To find the option, open the Start Menu, click on Settings, > Update & security > Recovery > Get started (under, the Reset this PC option)., , 'Keep my files' saves personal files but deletes user, settings, drivers and programs, whilst also reinstalling, Windows 10., , Upon selecting the option, it will present with three, separate options:, , 'Remove everything' also gets rid of personal files and, 'Restore factory settings' does the same actions as, 'Remove everything', but also resets the PC to the version, of Windows which came with the machine., , •, , Keep my files, , •, , Remove everything, , •, , Restore factory settings (not available on all PCs), , This option will only be available to those who bought a, pre-built PC or laptop which came with Windows already, pre-installed., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 41
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IT & ITES, Related Theory for Exercise 1.4.16, COPA - Computer basics & Software installation, Troubleshooting computer, Objectives: At the end of this lesson you shall be able to, • state the basic steps involved in troubleshooting a PC, • explain the basic approach to solve a problem, • list the probable defects and symptoms in a faulty Computer, • analyse the causes for the complaints, • state the shortest path for servicing the defects., • list the probable defect and symptoms in the faulty Computer, • analyse the causes for the complaint “When windows is started, system runs surface test and goes to, safemode” with the help of a Problem Tree and TSC, Basic Troubleshooting, One of the difficulties while troubleshooting problems on, a PC is that in most cases they are not what they seem., The cause behind a frequent hanging of a PC may be due, to one of six or more well defined areas or a dozen of, unidentified problems. The problem could be due to, software or hardware. Even with years of experience and, training, PC technicians come out with troubleshooting, procedures that do not solve the real problem. For, example a personal computer running windows operating system with several i/o cards connected may freeze, the screen , mouse, and keyboard and take as long as 3, minutes before responding. After trying out with all the, options like replacing a memory module, installing new, parallel port and NIC drivers, the technician finally checks, the system logs to find that a vital operating system, library was corrupted and needed to be reinstalled. The, issue to be mentioned here is that if the technician used, a systematic approach to troubleshooting, the problem, would likely have been solved much sooner. Maintaining, a good troubleshooting plan certainly gives us the scope, to approach the problem in a more systematic and, scientific manner. A troubleshooting plan is nothing but, a written check list that we use for any problem. The, elements that should be included in any troubleshooting, plan are as follows, – Maintenance record, – Identification of possible causes, – Identification of possible solutions, – Application and testing of solutions, – Follow-up, In the maintenance record, record the hardware installed, in the PC when it is installed, all preventive maintenance, activities, all software updates or additions, and all, hardware installations and upgrades. Further any problems that occur and the actions you take to resolve them, should be recorded . when it comes to troubleshooting a, PC, with the maintenance record one can pin down a, problem and devise solution for it. The first entry in such, record should be a profile of the PC, which includes its, configuration, operating system, and the date each, component was installed., 42, , Such tables gives an idea of the type of information one, should include in the sytem configuration, as summerised, below:, – The processor’s make, model and speed., – Amount of system memory(RAM) and the memory, module type, size and configuration of the memory, – Hard disk size and the type of interface, – Make, model and speed of the compact disk (CD) or, digital versatile disk ( DVD) drive, – Memory size of the video or graphics adapter, – Make, model, type and speed of the modem, – The version number of the operating system, – A list of software applications installed on the PC, – A list of peripheral equipment attached to the PC,, indicating the port to which they are attached, The maintenance record should be updated each time any, maintenance work is carried over on the PC. Any time new, or replacement hardware is installed, record the activity, and update the system configuration. The activity entries, should include, – Date of the activity or changes made to the system, – The make, model and serial number of any hardware, removed or added to the PC, – The name, version and publisher of any software added, to the PC, – Detailed information on any configuration changes, made to the basic input/output system(BIOS) or other, configuration for the new device or software., Troubleshooting approach, For solving any problems associated with PC, first go, through the maintenance record of that PC and follow a, systematic procedure for isolating the problem. The, standard problem solving process includes the following, steps, Identify the problem: This is the most difficult part of the, process. To perform this step successfully collect all the, data about the problem, , Copyright @ NIMI Not to be Republished
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Identify possible causes: analyse all the symptoms of, the problem and try to list all the causes in order from the, most likely to the least likely., Identify possible solutions: identify solutions for each of, the causes that are identified. A possible cause could have, more than one possible solution., Analyze the possible solutions: if two solutions produce the same result, consider the one which is more, economic and apply the same., After following the above steps and on solving the, problem update the maintenance record and make, necessary entries into it. In some cases the problems, may be very clear and the solution is very transparent and, even in such cases try to follow the above mentioned steps, to make it a practice to follow the systematic approach., Whenever a problem occurs with a PC, while following the, steps, try to collect the information about the system by, answering questions such as, – Under what circumstances this problem cropped up?, – Were there any indications in the form of beep codes/, error messages or any clear symptoms?, – What softwares were active when the problem happened?, – Has it happened for the first time or occurred in the past, also?, – Were there any configuration changes made during, the session that required a restart that was not, performed?, Optimizing the PC:, A PC which was functioning absolutely well and developed, a symptom of slowing down or if it is unable to keep pace, with the demands of newer software, one of the possible, solutions is to consider updating or optimizing the PC to, enhance its performance. Optimization steps may cost, money , but many involve software you already own or, software readily available on the web., , they are installed out of order, but there is some benefit to, be gained from putting them in the proper sequence. On a, Pentium system, use PCI cards and avoid ISA cards, if, possible. All I/O adapters including video cards, sound, cards, NICs, modems and SCSI adapters are available for, the PCI expansion bus. Consult the motherboard documentation and install video card in the first PCI slot,, followed by the NIC, modem, and sound card, in that order., Optimizing the processor: One can speed up the processor in the following ways, – Replace it with a faster speed or higher level processor, – Use a utility from the processor manufacturer to apply, patches or fixes to the processor’s logic, – Overclock the processor, The requirement for replacing the processor with a higher, level or faster processor is that your motherboard and, chipset will support the new processor both logically and, physically. Logically the chipset and motherboard must, support the bus speed of the processor and have the, supporting circuits it requires. It is often much better to, replace the complete motherboard. Some times the manufacturer of the processor may release some utilities that, will improve some aspect of processor’s capabilities such, as video processing, buffer handling, caching and other, processor based functions. Overclocking a processor, means running a processor at speeds faster than it was, released to support. Most processors are capable of, running at speeds higher than their nominal speeds. The, nominal speed of a processor is the speed at which it has, been tuned to run with a certain chipset, motherboard,, cooling system, and other components of the PC. Raising, the speed of the processor can create heating problems on, the processor and lead to frequent system lockups,, memory problems and other issues., Troubleshooting sources of Non-software problems:, Any time pc fails for no apparent software reason, check, the following areas, , Optimizing the BIOS and Boot process:, , – Ensure proper AC power, , BIOS setup configuration includes many settings in the, CMOS. How quickly the system boots and performs, depends on the these settings. Enabling of valuable, features such as system caching or using the quick, POST process are very vital for optimum peroformance., , – Scan the PC for a computer virus, , Optimizing the hard disk: Windows ScanDisk and Disk, Defragmenter utilities are the best tools available for, optimizing the hard disk in terms of usage and access, speeds. ScanDisk is used to check a disk for errors and, repair them or remove unrecoverable areas of the disk, from the usage tables to prevent future errors. Similarly, Disk Defragmenter organizes data file fragments into a, more optimized and logical format that provides for, faster access times and less head movement., Optimizing the Expansion cards: The best way to, optimize I/O controllers and other expansion cards is to, install them in the correct order. No harm is done even if, , – Ensure that CPU fan is spinning, – Ensure proper connections of external I/O connectors, – Reseat the expansion cards and check the power and, data cables of internal devices, – Most of the boot problems are the result of a recent, change, check out the BIOS setup configuration data, – To install any new hardware or software, visit manufacturer’s web site for any known conflict or incompatibility, – Check for any resource conflict if any new hardware or, software is installed., The forth coming lessons on Troubleshooting PC are, provided with Problem Trees for different type of problems, which a user face normally. Each Tree with a specific, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 43
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problem gives scope to analyse the areas to be suspected, or looked into for fixing the problem. This lesson includes, a Problem Tree for a PC which is Dead with no display on, monitor., PROBLEM TREE : PT- 01, Observed symptom, , : Dead, , Additional symptom, , : No display, , PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”., Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , 44, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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SAFE MODE, SURFACE SCAN TEST, , HDD, BAD SECTORS, , OS, , Discuss the Troubleshooting chart (TSC-01) and Service flow sequence (SFS-01) for the complaint “When, windows is started system runs surface test and goes to safemode” referring to exercise 2.33, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 45
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PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , Observed symptom, , PROBLEM TREE : PT- 03, : DVD drive can’t read, , Additional symptom, , :, , 46, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.17, COPA - Computer basics & Software installation, Application softwares, Objective: At the end of this lesson you shall be able to, • describe various software types., Application software, Application software is a term which is used for software, created for a specific purpose. It is generally a program, or collection of programs used by end users. It can be, called an application or simply an app., In fact all the software other than system software and, programming software are application software., Application software definition, A software which is developed to help the user to perform, specific tasks is called application software., The different types of application software include the following:, Application Software Type, , Examples, , Word processing software, , MS Word, WordPad and Notepad, , Database software, , Oracle, MS Access etc, , Spreadsheet software, , Apple Numbers, Microsoft Excel, , Multimedia software, , Real Player, Media Player, , Presentation Software, , Microsoft Power Point, Keynotes, , Enterprise Software, , Customer relationship management system, , Information Worker Software, , Documentation tools, resource management tools, , Educational Software, , Dictionaries: Encarta, BritannicaMathematical:, MATLABOthers: Google Earth, NASA World Wind, , Simulation Software, , Flight and scientific simulators, , Content Access Software, browsers, , Accessing content through media players, web, , Application Suites, , OpenOffice, Microsoft Office, , Software for Engineering and Product Development, , IDE or Integrated Development Environments, , Copyright @ NIMI Not to be Republished, , 47
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There are various different types of application software, such as licensed, sold, freeware, shareware and open, source., Application software's either need to be installed or can, run online. Application software's can also be distinguished, on the basis of usage into the following:, •, , Utility programs, , •, , Generic programs, , •, , Integrated programs, , •, , Specific software, , •, , Bespoke software, , •, , Word processing software, , 48, , •, , Desktop publishing software, , •, , Spreadsheet software, , •, , Database software, , •, , Presentation software, , •, , Internet Browsers, , •, , Email Programs, , •, , Graphic Programs (Pixel based), , •, , Graphic Programs (vector based), , •, , Communication software: Communication through, audio, video or chat based means, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.17, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.18&1.4.19, COPA - Computer basics & Software installation, Bluetooth devices, Objectives : At the end of this lesson you shall be able to, • describe the meaning of Bluetooth, • describe the method of using Bluetooth, • list the major applications of Bluetooth., Introduction:, Bluetooth is a wireless technology standard for, exchanging data over short distances (using shortwavelength UHF radio waves in the range 2.4 to 2.485, GHz) from fixed and mobile devices, and building, personal area networks (PANs). It is a standard wirereplacement communications protocol primarily designed, for low-power consumption, with a short range based on, low-cost transceiver microchips in each device., It can connect up to eight devices (items of electronic, equipment) at the same time. The chip can be plugged, into items such as computers, digital cameras, mobile, phones and faxes. Bluetooth is particularly convenient, in certain situations - for example, when transferring files, from one mobile phone to another without cables., Sending music and photos between a PC and a mobile, phone is another useful application., Because the devices use a radio (broadcast), communications system, they do not have to be in visual, line of sight of each other, however a quasi optical, wireless path must be viable., Range is power-class-dependent, but effective ranges, vary in practice varying from 10 to 100 m., The name 'Bluetooth' reflects the Scandinavian origins, of the technology. It is named after a 10th century Danish, viking, King Harald Blåtand (translating as 'Bluetooth' in, English).He united and controlled Denmark and Norway,, hence the association of uniting devices through, Bluetooth., , When devices like mobile phones, laptops, tablets etc., enable Bluetooth the Bluetooth icon is on., To establish a Bluetooth connection:, 1 Find the file you wish to send., 2 Select the option to send it via Bluetooth - your device, will search for other devices within range and display, them., 3 Scroll to the device you wish to connect with and, select it., 4 If the other device needs 'pairing', you will need to, enter a passcode - a bit like a PIN number - and make, sure it is entered on the other device., When the connection is established, the data will start to, send. You do not need worry about a clear line of sight, between devices., List of Bluetooth applications, Some of the Bluetooth applications are as follows:, Wireless control of and communication between a mobile, phone and a handsfree headset.(Refer fig. 1), , Fig 1, , To use Bluetooth, the device must be Bluetooth enabled., For this purpose a device called "Dongle"may be used., A dongle is a device that plugs into the computer to, enable it to use Bluetooth. Every manufacturer of, compatible devices will have their own instructions for, accessing Bluetooth. For detailed instructions you will, need to see the manual, but as a general guide:, To set up Bluetooth:, (Identify the blue tooth icon on devices.), 1 Turn on, or enable, Bluetooth. Ensure your device is, 'visible' and not 'hidden', so other nearby devices can, pick up the signal., 2 Give your device a name to identify it when, connecting to other compatible equipment., , Copa 118290A1, , Using Bluetooth, , • Wireless control of and communication between a, , mobile phone and a Bluetooth compatible car stereo, system., , • Wireless control of and communication with tablets, and speakers such as iPad and Android devices., , • Wireless networking between PCs in a confined space, and where little bandwidth is required., , • Wireless communication with PC input and output, , devices, the most common being the mouse,, keyboard and printer., , Copyright @ NIMI Not to be Republished, , 49
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• Transfer of files, contact details, calendar, , appointments, and reminders between devices with, OBEX(Objects exchange)., , • Replacement of previous wired RS-232 serial, , communications in test equipment, GPS receivers,, medical equipment, bar code scanners, and traffic, control devices., , Wi-Fi:, Wi-Fi is a popular wireless networking technology. WiFi stands for "wireless fidelity". The Wi-Fi was invented, by NCR corporation/AT&T in Netherlands in 1991. By, using this technology we can exchange the information, between two or more devices. Wi-Fi has been developed, for mobile computing devices, such has laptops, but it is, now extensively using for mobile applications and, consumer electronics like televisions, DVD players and, digital cameras. There should be two possibilities in, communicating with the Wi-Fi connection that may be, through access point to the client connection or client to, client connection. Wi-Fi is a one type of wireless, technology. It is commonly called as wireless LAN (local, area network). Wi-Fi allows local area networks to, operate without cable and wiring. It is making popular, choice for home and business networks. A computer's, wireless adaptor transfers the data into a radio signal, and transfers the data into antenna for users., , Fig 1, , • Wireless bridge between two Industrial Ethernet, networks., , • Wireless controllers in gaming consoles., • Personal security application on mobile phones for, prevention of theft or loss of items. The protected, item has a Bluetooth marker (e.g., a tag) that is in, constant communication with the phone. If the, connection is broken (the marker is out of range of, the phone) then an alarm is raised., , And can now generate a system within Resorts, library,, schools, colleges, campus, personal institutes, as well, as espresso stores as well as on the open public spot to, help to make the company much more lucrative as well, as interact with their own customer whenever. Wi-Fi, compatibility can make surf with stare to company using, their inspiring cable television much a smaller amount, force down., The radio signals are transmitted from antennas and, routers that signals are picked up by Wi-Fi receivers,, such has computers and cell phones that are ready with, Wi-Fi cards. Whenever the computer receives the signals, within the range of 100-150 feet for router it connect the, device immediately. The range of the Wi-Fi is depends, upon the environment, indoor or outdoor ranges. The, Wi-Fi cards will read the signals and create an internet, connection between user and network. The speed of the, device using Wi-Fi connection increases as the computer, gets closer to the main source and speed is decreases, computer gets further away., , Copa 1121802, , Copa 1121801, , Fig 2, , Working Principle:, Wi-Fi is a high speed internet connection and network, connection without use of any cables or wires. The, wireless network is operating three essential elements, that are radio signals, antenna and router. The radio, waves are keys which make the Wi-Fi networking, possible. The computers and cell phones are ready with, Wi-Fi cards. Wi-Fi compatibility has been using a new, creation to constituent within the ground connected with, community network. The actual broadcast is connected, with in sequence in fact it is completed by way of stereo, system surf as well as the worth of wires with monitor to, classification prone. Wi-Fi allows the person in order to, get access to web any place in the actual provided area., , 50, , Security:, Security is impartment element in the Wi-Fi technology., Security is our personal decision but having a wireless, connection we should pay attention to protect our private, details. We can connect easily to unsecured wireless, routers. The problem is any one is connected to, thewireless router using the data like download games,, download apps and planning terrorist activities, shirring, illegal music and movie files etc. So it is necessary to, provide security to the wireless technologies based, devices., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.18 & 1.4.19, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.20, COPA - Computer basics & Software installation, DVDs, CDs and burning DVDs, Objectives : At the end of this lesson you shall be able to, • describe the features of CDs & DVDS, • describe the main formats of DVDs, • describe DVD burning, • describe the features of CDs., Introduction, DVD (sometimes called as "digital video disc" or "digital, versatile disc") is a digital optical disc storage format., DVDs can be usedwith many types of players, including, PCs and standalone players., These discs are known as DVD-ROM, because data can, only be read and not written or erased. Blank recordable, DVD discs (DVD-R and DVD+R) can be recorded once, using a DVD recorder and then function as a DVD-ROM., Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM), can be recorded and erased multiple times., DVD features and formats, DVDs are used in DVD-Video consumer digital video, format and in DVD-Audio consumer digital audio format., They can also be used in a special AVCHD format (, Advanced Video Coding High Definition) often used with, AVCHD format camcorders. DVDs containing other types, of information may be referred to as DVD data discs., A typical recordable DVD can hold about 4.7 gigabytes, (GB). However, the total amount of disc space that you, can use to burn files to the disc is less than the amount, that's often listed on the disc itself. This is because the, disc capacity is calculated differently when it's used in a, computer. For example, a typical DVD-R that has a listed, disc capacity of 4.7 GB can only store about 4.37 GB of, data on the disc. DVDs offer a storage capacity of, approximately 4.7 GB. DVD discs do not deteriorate over, time and are unaffected by magnetic fields., The type of recordable disc to be used depends on a, few different factors, such as:, , • The types of recordable discs that work with the disc, burner., , • The disc drive on the computer or device will read, the disc after it is burned., , • The total size of all the files that will be burned on to, a disc., , DVD burning, The process of recording source material onto an optical, disc (CD or DVD) is called burning / writing or optical, disc authoring.Creating an optical disc usually involves, first creating a disk image with a full file system designed, for the optical disc, and then actually burning the image, to the disc. Many programs are available as bundled, applications to create the disk image and burn the files., , The speed at which a DVD can be written is expressed, as a multiplier: 16X means 16 times faster than just, playing it. Speeds upto 52X are also very common., CD or DVD formats, For burning DVDs, the two main disc formatsin use are:, , • Live File System and, • Mastered disc formats., Live File System format :, Discs that use the Live File System format are often, more convenient because you can copy selected files, immediately and as often as you want, just like you can, with a USB flash drive. This is convenient if you want to, keep a disc in your CD, DVD, or Blu ray Disc burner and, copy files whenever the need arises. In this format you, can copy and erase files over and over again. However,, the Live File System optical disc format is only readable, by Windows 7, Windows Vista, and Windows XP, systems. These discs are not blank after they're, formatted., Discs formatted in this format have the option name in, the Burn a Disc dialog box: "Like a USB flash drive.", Mastered disc formats:, If we want to create an optical disc that can be used to, transfer data files to older versions of the Windows, operating system or even to another operating system,, weneed to use the Mastered optical disc format. Also if, we want to burn music or pictures and use the disc in, regular CD, DVD, or Blu ray Disc players that can play, MP3 files and show digital pictures, we should use the, Mastered optical disc format., The Mastered format works just like burning CDs in, Windows XP. In other words, when we write the disc, we, copy a file or a group of files to the optical disc all at, once. Once this is done, the disc is closed and we cannot, copy more files to the disc nor can we delete the existing, files.Hence it is recommended not to copy files, immediately; it is a good practice to assemble the entire, collection of files that needed to be copied to the disc, and then burn them all at once., Discs formatted with the Mastered option have the option, in the Burn a Disc dialog box: "With a CD/DVD player.", There are many types of tools available to create data,, music, video and audio discs. We can also create, , Copyright @ NIMI Not to be Republished, , 51
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backups that span across multiple discs, rip music tracks, from Audio CDs and create or burn disc images in, different formats. They may also provide features like, automatic audio conversion from WAV, MP3, FLAC,, WMA files, disc copying, compressed file backup and, restore, disk erasing, VCD/SVCD support, project burning, etc.., , The following formats are part of the present day Bluray Disc specification:, , Blu - ray Discs, , 3, , Blu-ray, also known as Blu-ray Disc (BD) is the name of, a new optical disc format that is rapidly replacing DVD., The format was developed to enable recording, rewriting, and playback of high-definition video (HD), as well as, storing large amounts of data. The format offers more, than five times the storage capacity of traditional DVDs, and can hold up to 25GB on a single-layer disc and 50GB, on a dual-layer disc., , 1 BD-ROM - read-only format for distribution of HD, movies, games, software, etc., 2 BD-R - recordable format for HD video recording and, PC data storage., BD-RE - rewritable format for HD video recording, and PC data storage., , At present, a single-layer disc can hold 25GB and a duallayer disc can hold 50GB. Over 9 hours of high-definition, (HD) video on a 50GB disc. About 23 hours of standarddefinition (SD) video on a 50GB disc., , The name Blu-ray is derived from the underlying, technology, which utilizes a blue-violet laser to read and, write data. The name is a combination of "Blue" (blueviolet laser) and "Ray" (optical ray). They are referred to, as "Blu-ray" discs or BDs., , 52, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.20, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.21, COPA - Dos & Linux operating systems, Comand line interface with DOS, Objectives: At the end of this lesson you shall be able to, • describe the hierarchical directory system in DOS, • use dos commands to create directories and subdirectories, • use dos commands to change and list directory, • use dos commands to access specific files., Hierarchical Directory System: Hierarchy in simple, terms, is, organisation or an arrangement of entities., Entities can be anything such as objects, files, people,, ideas, or any other thing., Arrangement refers to, for example, Currency can be, arranged by denomination. Pebbles can be arranged by, their size ., There are many other ways to organize entities besides, hierarchically. But, hierarchical organization is special, because by this arrangement you can name each entity, by its relationship to other entities., In DOS, entities are the Directories in a directory system., Here, the hierarchy begins with the essential core or root, entity. For instance, in a family tree, we may consider, great-great-grand father who was the root cause of our, existence as the core entity. In DOS , this core entity is, referred to as the the root directory., As in the example considered above, if we consider, great-great-grand father as the root directory, then, greatgrand father, grand father, father are referred as sub, directories. So the directories under the root directory are, called subdirectories in DOS. These subdirectrories can, trace their paths back to the root directory., , In a family tree, say, Govinda is the son of Rajappa, who, is son of Ramappa who is son of Venkappa. Venkappa, is the head or root of the family tree for Govinda., One can create many directories from the root. The root, will then be the parent of each of these directories. You, can also create subdirectories that stem from other, subdirectories that stem from other subdirectories and so, on. These new subdirectories have a subdirectory as, their parent directory. How subdirectories are arranged, hierarchically from the root is illustrated in Fig 1. The, DOS directory system is often called a tree-structured, directory system., Three levels of subdirectories are represented in Fig 1., Regardless of the number of levels, the relationship of, the subdirectories is important. Each subdirectory, as, well as the root directory, can contain user files. Two files, can have the same file name and extension as long as the, files reside in different directories. This is because, DOS, needs to know which of two same-named files your, command specifies. For this, DOS needs the name of the, directories,starting from the root, that lead to the desired, file. This sequence of directory names leading to a file is, called a path., , The DOS hierarchical file system is called a tree-structured, file system. At the base of this tree structure is the root, directory., Fig 1, , ROOT, , a1, , LEVEL - 2, , LEVEL - 3, , B, , A, , LEVEL - 1, , a11, , a2, , a21, , D, , C, , c1, , c2, , c21, , Copyright @ NIMI Not to be Republished, , a22, 53
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A path is a chain of directory names that tell DOS how to, find a file that you want. Each directory is seperated from, the other by a ‘ \ ’ character. This ‘ \ ’ is referred to as the, DOS directory delimiter. A files full path name including, the drive specifier ( C: or D: etc.,) is the absolute indicator, of where the file is located. Typical path notation are, given below;, D:\Animals\Domestic\Pets\Dog.txt, C:\Admin\Accounts\Tours\Bata.txt, Further details of path and directory structure, will be discussed at appropriate lessons., DOS COMMANDS, 1, , MKDIR, , Makes or Creates a new Directory., , MKDIR\Drivers, Or, MD\Drivers, C:\Devices>MD \Printers, This instruction creates a subdirectory by name Printers, under the current drive C:. Note that although the, command is issued from another subdirectory named, devices, the newly created subdirectory Printers does, not get created under the directory Devices but directly, under the root C:. This may be verified by issuing DIR, command under C:\ and under C:\Devices., To create a subdirectory under the directory Devices the, instruction will be,, C:\Devices>MD Printers, Discuss the following different varieties of creating, directories:, , or, MD, , C:\Devices\Printers>MD C:\Devices\Plotters, , Syntax, MKDIR C:path\dirname, Or, , 2, , CHIDR or CD, , Changes or shows the path of the current directory., Syntax, , MD d:path\dirname, , CHIDR d: path, , Where,, C: is the disk drive for the sub directory, path\ indicates the path to the directory that will, hold the subdirectory being created., dirname is the name of the subdirectory being, creating., Switch, (None), Important Notes, – MKDIR or its short form MD makes new, subdirectories under the selected root directory., – It is possible to create as many subdirectories as, you want , but remember: DOS accepts no more, than 63 characters, including backlashes, for the path, name., – Do not create too many levels of subdirectories and, with long names., – You cannot create a directory name that is identical to, a file name in the current directory., For example, if you have a file named FLIES in the, current directory, you cannot create a subdirectory by the, name FLIES in this directory. However, if the file FLIES, is given an extension FLIES. DOC , then the names will, not conflict and you can create a subdirectory by name, FLIES., Examples, , Or, using the short form:, CD d : path, D : path are valid disk drive and directory names., Switch, (None), You have two methods for maneuvering through, the hierarchical directories with CD: (1) starting, at the root , or top, directory of the disk and, moving down, or (2) starting with the current, directory and moving in either direction., To start at the root directory of a disk, you must begin the, path with the path character (\), as in \ or B:\. When DOS, sees \ as the first character in the path, the system starts, with the root directory. Otherwise, DOS starts with the, current directory., Changing Drives: Computer will have built in memory,, the hard disk and it will also have provision to store/read, data from floppy disk, compact disk etc. Every disk is, identified by a name such as C drive, A drive, B drive etc., C drive is represented by C: and A drive is represented, by A: and so on. DOS allows to change from current or, default drive by typing the letter identification of disk, drive desired followed immediately by a colon as shown, in the example below:, C\> a:, , To create the subdirectory by name Drivers under the, current drive, the instruction will be,, 54, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished
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This command instructs to change control from C drive to, D drive., , H Hidden files, , If the disk drive is not accessed due to non availability of, floppy or any other reason, DOS will display an error, message, , A Files ready to archive - Prefix meaning “not”, , S System files, / O List be files in sorted order., sorted N By name (alphabetic), , Not ready error reading drive A, , S By size (smallest first), , Abort, Retry, Fail ?, , E By extension (alphabetic), , It is required to press either A,R or F keys, which are, defined below, , D By date & time (earliest first), G Group directories first, , A Directs DOS to abort the command that was, responsible for the error. If this option is selected, DOS will terminate the command and redisplay, prompt., , - Prefix to reverse order, C By compression ratio (smallest first), , R Directs DOS to retry the command that caused the, error. In most cases this option is selected to correct, the the problem that was causing the error. (Floppy, disk might not be inserted)., , /S, , Displays files in specified directory and all, subdirectories., , /B, , F Directs DOS to ignore the error and attempt to, continue processing. In some cases DOS will have, an error when it reads a portion of disk., , Uses bare format (no heading information or, summary)., , /L, , DOS COMMAND, DIR, , Displays a list of files and subdirectories in, a directory., , Syntax, DIR C:path/filename [/P] [/W] [/A[[:]attribs]] [/O[[:]sortord]], [/S] [/B] [/L] [/C[H]], , Where,, –, , C: is the disk drive holding the directory for, displaying list of files and subdirectories, , –, , path/ specifies directory and/or files to list., , –, , filename specifies file or list of files to display,, if file name is not specified all the files in the, directory will be listed., , –, , [/P] [/W] ......... specifies the switches for, formatting the output., , Switch, /P, , Pauses after each screenful of information and, waits to press any key. On pressing any key, another screenful or remaining information will, be displayed. Command is DIR/P, , /W, , Uses wide format of 80-column to display file, names only and information about file size,, date, and time is not displayed. Command is, DIR/W, , /A, , Displays files with specified attributes., , Uses lowercase., , / C[H] Displays file compression ratio; /CH uses host, allocation unit size., Important Notes:, – In the directory listing similar files can be listed by, using wildcards (* and ?), where (*) star and (?), question mark are called wild characters or wild cards., * can replace remaining charecters and ? can replace, any single character., – When DIR is used without parameters or switches, It, displays the disks volume label and serial number;, one directory or filename per line, including the file, size in bytes, and the date and time the file was, modified; and the total number of files listed, their, cumulative size and the free space ( in bytes), remaining on the disk., Examples, DIR *.txt, *.txt instruction will list all files having txt extension, in the specified directory., DIR ???T.*, ???T instruction will search for files having four, characters which ends with T like TEST,, REST etc. And * instructs that these files may have, any extension like .txt, .dat etc., , attribs, D Directories, R Read-only files, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished, , 55
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IT & ITES, Related Theory for Exercise 1.5.22, COPA - Dos & Linux operating systems, Methods to display the contents of a text file, Objectives: At the end of this lesson you shall be able to, • use DOS commands to display the contents of a text file, • use DOS commands to copy,rename,delete and undelete files., DOS Commands, , Examples, , TYPE Displays the contents of a text file., , 1 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt, , Syntax, , C:\COPA\DOS\PRACT_3 is the path to the file, TEST.txt and TYPE is the command to be executed, by DOS., , TYPE C:path/filename, Where,, –, , C: is the disk drive holding the file for displaying., , –, , path/ Specifies the location of file for displaying., , –, , filename specifies file to display., , Switch, , 2 C:\>TYPE C:\COPA\DOS\PRACT_3\>TEST1.txt, This results in the same output as in example1. While, working from C: (C drive) this command can be, issued with out changing the directories., 3 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt | MORE, This will also result in the same output but displayed, screen page by screen page. Screen page can be, changed on press of any key. Along with MORE, another character is prefixed ‘|’ this called the piping, command, Which will route the output of TYPE, command to another command MORE and the, MORE filter outputs the information., , (none), Important notes:, – TYPE command provides a quick way to display, contents of an ASCII file with out having to use, another program. The file is stored on the disk as, ASCII (American Standard code for Information, Interchange) text. which is standard way the computer, translates binary ( ones and zeros) into letters,, numbers & symbols. If the information is not stored in, the ASCII format, on using TYPE command the, information will look like gibberish., – On issuing command DOS will look in drive specified,, moves into the path to reach the filename specified., Then it simply translates ASCII format into the, characters, numbers and symbols and displays on, the monitor. The video monitor can show 24 lines of, information only. if the file contains more than 24, lines starting lines can not be seen since the type, command simply scrolls all information on to the, screen. Scrolling can be controlled by pressing, Control + S keys together (on holding control key, press S key and release both the keys is called as, Control + S) scrolling of information will stop on the, monitor. After viewing the contents on the screen any, key can be pressed to scroll through the remaining, contents. To view the contents of the file screen page, by screen page, MORE command can also be used., which will stop the scrolling of information on the, screen exactly after a screen page and in the screen, page at 24 line a prompt message — More— is, displayed. After pressing any key another screen, page will be displayed. MORE is a filter e.g. itis a, program that manipulates the stream of standard, characters to the file to the standard output (monitor), screen page by screen page., , 56, , Renaming of file(s), RENAME, Or, , This command allows to change, the name of a file., , REN, Syntax, REN C: PATH\filename1.ex1 filename2.ex2, Where,, – C: is the disk drive holding the file for displaying., – PATH/ Specifies the location of file for displaying., – filename1.ex1 is the file to be renamed, – filename2.ex2 is the new filename, Important Notes:, – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be renamed., – A valid file name with appropriate extension is to be, given for new filename., – Wild characters are permitted in the file names by, which required group of files can be renamed., , Copyright @ NIMI Not to be Republished
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– Only file names will be changed and contents remain, same., – If attempted to change a file name to a name that, already exists in the directory., DOS prompts an error message, , Instructor shall discuss the simple switches, with at least two examples in each case ., For further details on COPY command switches, refer any tutorial or hand book on DOS, Important Notes:, , Duplicate file name or file not found, – If a invalid file name or the new name is not given,, then also DOS prompts an error message, Rules for the file names., – A File name must have 1 to 8 characters., – An optional extension of 1 to 3 characters, – A period (.) between the name and extension name,, if extension is used, – All letters from A through Z ( lower case letters are, automatically transferred to uppercase), 0 to 9, numbers and special characters & symbols $ # & @, ! ^ ( ) _ - { } ‘ ~ are permitted in the file name., , – DOS command COPY can duplicate one or more, files. In the same directory with different names or, from one directory to other directory either in the, same name or in different name., – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used., – Exact file name with extension is to be given for the, file to be copied, – A valid file name with appropriate extension is to be, given for new copied filename, , – The control characters such as Esc, Del, or space bar, cannot be used in the file name., , – Wild characters are permitted in the file names by, which required group of files can be copied, , – The characters + = / [ ] : ; ? * < > : are not permitted., , – On copying, both source and target files will have, same contents., , – Each file name in a directory must be unique., Examples:, , – Copy overwrites the target file with the same name, , TEST2.txt, , – Copy will not allow to copy a file to it self that is source, and target files should not be same, , C:\COPA\DOS\PRACT_3\ is the drive and path to the, TEST2.txt file, TEST2.txt is the file name to be renamed, , – If the destination file name is not specified while, concatenation the first file name will become the, destination name. After the first file name, additional, source files must be preceded by a plus (+) sign., , CHECKED.txt is the new filename, , Example, , 1 C:\COPA\DOS\PRACT_3\>REN, CHECKED.txt, , 2 C:\COPA\DOS\PRACT_3\>REN *.pic *.jpg the pic, extension will be changed to jpg extension files., Copying files:, COPY Copies one or more files to another location., Syntax, COPY [/A | /B] source [/A | /B] [+ source [/A | /B] [+ ...]], [destination[/A | /B]] [/V] [/Y | /-Y] source specifies the file, or files to be copied. Destination specifies the directory, and/or filename for the new file(s)., Switches, /A, , Indicates an ASCII text file., , /B, , Indicates a binary file., , /V, , Verifies that new files are written correctly., , /Y, , Suppresses prompting to confirm you want to, overwrite an existing destination file., , /-Y Causes prompting to confirm you want to overwrite, an existing destination file., , 1 C:\COPA\DOS\PRACT_3\>COPY, TRIAL.txt, , TEST2.txt, , With the above command C:\COPA\DOS\PRACT_3, directory TEST2.txt file will be copied as TRIAL.txt, file in the same directory. On listing the directory both, the files will have same details and on viewing the, contents of both the file will be same. After copying, DOS prompts a message 1 file copied, 2 C:\COPA\DOS\PRACT_3\>COPY *.bmp *.pic, With the above command C:\COPA\DOS\PRACT_3, directory all files with bmp extension file will be, copied as pic extension files in the same directory., While copying DOS prompts the name of file it has, copied and after completion of copying it prompts the, number of files copied., 3 C:\COPA\DOS\PRACT_3\>COPY, C:\COPA\DOS\PRACT_4\, , *.pic, , All files with pic extension in C:\COPA\DOS\PRACT_3, directory will be copied to C:\COPA\DOS\PRACT_4, directory with same name & extension., Using *.* after the copy command will copy all files, with all extension to the destination., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 57
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Copy concatenating: Multiple file can be combined to, form a single file by use of + between the source files and, is called, as concatenation, Example 4 C:\COPA\DOS\PRACT_3\ COPY TEST2.txt, + TRIAL.txt CONCAT1.txt, With the above command TEST2.txt and TRIAL.txt will, be combined and CONCAT1.txt file will be created which, will have the contents of first two source files., Deleting file, DEL, , Deletes the files specified., , or, Erase, Syntax, DEL C:path/filename [/P], ERASE C:path/filename [/P], Where,, –, , C: is the disk drive holding the file to be deleted., , –, , path/ Specifies the location of file to be deleted., , –, , filename is the file to be deleted, , Switch, /P Prompts for confirmation before deleting the specified, file. Using the /P switch, If the /P switch is used, DEL displays the name of a file, and prompts with a message in the following format:, filename, Delete (Y/N)?, Press Y to confirm the deletion, N to cancel the deletion, and display the next filename (if a group of files are, specified), or CRTL+C to stop the DEL command., Important Notes, – If the drive is not specified current disk drive will be, used, – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be deleted, , The following command is given for deleting all the files., del *.*, DEL displays the following prompt:, All files in directory will be deleted! Are you sure (Y/N)?, Press Y and then ENTER to delete all files in the, current directory, or, press N and then ENTER to cancel the deletion., –, , Directories can not be removed with DEL command, a separate command is available for removing the, directory., , – Once the file is deleted it can not be recovered if the, memory space is occupied by a new file. If accidentally, file (s) are deleted immediately it can be recovered, by using utility command., – The space occupied by the deleted file on the disk or, diskette is freed., – Check for the typographic errors in the file names, before the press of enter key to activate delete, command, Example, 1 C:\COPA\DOS\PRACT_3\>DEL TEST2.txt, With the above command TEST2.txt file will be, deleted from the C:\COPA\DOS\PRACT_3 directory., On listing the directory TEST2,txt will not be available., 2 C:\COPA\DOS\PRACT_4\>DEL *.txt, With, the, above, command, in, the, C:\COPA\DOS\PRACT_4 directory all files with txt, extension will be deleted., 3 C:\COPA\DOS\PRACT_3\TEMP \> DEL *.*, All files with any extension in, C:\COPA\DOS\, PRACT_3\TEMP directory will be deleted., Recovering deleted files:, UNDELETE, , delete protection facility, , Syntax, UNDELETE C:path/filename [/DT | /DS | /DOS], , – Wild characters are permitted in the file names by, which required group of files can be deleted, , UNDELETE [/LIST | /ALL | /PURGE[DRIVE] | /, STATUS | /LOAD | /UNLOAD, , – On deleting, files name(s) will be removed from the, directory., , /UNLOAD | /S[DRIVE] | /T[DRIVE]-entrys ]], , – All the files in a directory can be deleted by typing the, DEL command followed by [drive:]path. Wildcard, also can be used (* and ?) to delete more than one file, at a time. However, Wildcards should be used, cautiously with the DEL command to avoid deleting, files unintentionally., , 58, , Where,, –, C: is the disk drive holding the files to be, undeleted., –, , path/ Specifies the location of file to be undeleted., , –, , filename is the file to be undeleted, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished
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Important Notes:, , Switches, /LIST, , Lists the deleted files available to be, recovered., , /ALL, , Recovers files without prompting for, confirmation., , /DOS, , Recovers files listed as deleted by, MS-DOS., , /DT, , Recovers files protected by Delete, Tracker., , /DS, , Recovers files protected by Delete, Sentry., , /LOAD, , Loads Undelete into memory for, delete protection., , /UNLOAD, , Unloads Undelete from memory., , /PURGE[drive], , Purges all files in the Delete Sentry, directory., , /STATUS, , Display the protection method in, effect for each drive., , /S[drive], , Enables Delete Sentry method of, protection., , /T[drive][-entrys], , Enables Delete Tracking method of, protection., , Once a file is deleted from disk, it may not be possible, to retrieve it. Although the UNDELETE command can, retrieve deleted files, it can do so with certainty only if, no other files have been created or changed on the disk., If a file is accidentally deleted and it is required to, keep, stop what all other activities on the computer and, immediately use the UNDELETE command to retrieve, the file., Example, 1 C:\COPA\DOS\PRACT_3\>UNDELETE TEST2.txt, With the above command TEST2.txt file will be, recovered. On listing TEST2.txt file will be available, in C:\COPA\DOS\PRACT_3 directory., 2 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE, With the above command multiple files can be, recovered. DOS will prompt for confirmation of, undeletion of each file and asks to type the first letter, of the file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen ., 3 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE /ALL, With the above command multiple files can be, recovered. DOS will not prompt for confirmation of, undeletion of each file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 59
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IT & ITES, COPA - Dos & Linux Operating System, , Related Theory for Exercise 1.5.23, , Introduction to Linux operating system, Objectives: At the end of this lesson you shall be able to, • overview of linux, • define futures of linux, • explain application area of linux, • describe about kernel., Overview of Linux, , Where is Linux?, , The operating system, , One of the most noted properties of Linux is where it can, be used. Windows and OS X are predominantly found on, personal computing devices such as desktop and laptop, computers. Other operating systems, such as Symbian,, are found on small devices such as phones and PDAs,, while mainframes and supercomputers found in major, academic and corporate labs use specialized operating, systems such as AS/400 and the Cray OS., , Developers need special tools (like the compilers and, command lines found in GNU) to write applications that, can talk to the kernel. They also need tools and applications, to make it easy for outside applications to access the, kernel after the application is written and installed., This collective set of tools, combined with a kernel, is, known as the operating system. It is generally the lowest, layer of the computer's software that is accessible by the, average user. General users get to the operating system, when they access the command line., Linux provides powerful tools with which to write their, applications: developer environments, editors, and, compilers are designed to take a developer's code and, convert it to something that can access the kernel and, get tasks done., Like the kernel, the Linux operating system is also, modular. Developers can pick and choose the operating, tools to provide users and developers with a new flavor of, Linux designed to meet specific tasks., Introduction to Linux, Linux (pronounced Lih-nucks) is a UNIX-like operating, system that runs on many different computers. Although, many people might refer to Linux as the operating, system and included software, strictly speaking, Linux is, the operating system kernel, which comes with a, distribution of software., Linux was first released in 1991 by its author Linus Torvalds, at the University of Helsinki. Since then it has grown, tremendously in popularity as programmers around the, world embraced his project of building a free, operating system, adding features, and fixing problems., Linux is popular with today's generation of computer, users for the same reasons early versions of the UNIX, operating system enticed fans more than 20 years ago., Linux is portable, which means you'll find versions, running on name-brand or clone PCs, Apple Macintoshes,, Sun workstations, or Digital Equipment Corporation, Alpha-based computers. Linux also comes with source, code, so you can change or customize the software to, adapt to your needs. Finally, Linux is a great operating, system, rich in features adopted from other versions of, UNIX., 60, , Linux, which began its existence as a server OS and Has, become useful as a desktop OS, can also be used on all, of these devices. ‚ÄúFrom wristwatches to, supercomputers,‚Äù is the popular description of Linux', capabilities., The future of Linux, Linux is already successful on many different kinds of, devices, but there are also many technological areas where, Linux is moving towards, even as desktop and server, development continues to grow faster than any other, operating system today., Linux is being installed on the system BIOS of laptop and, notebook computers, which will enable users to turn their, devices on in a matter of seconds, bringing up a, streamlined Linux environment. This environment will have, Internet connectivity tools such as a web browser and an, e-mail client, allowing users to work on the Internet without, having to boot all the way into their device's, primary operating system-even if that operating system is, Windows., At the same time, Linux is showing up on mobile Internet, devices (MIDs). This includes embedded devices such as, smart phones and PDAs, as well as netbook devicessmall laptop-type machines that feature the core, functionality of their larger counterparts in a smaller, more, energy-efficient package., The growth of cloud computing is a natural fit for Linux,, which already runs many of the Internet's web servers., Linux enables cloud services such as Amazon's A3 to, work with superior capability to deliver online applications, and information to users., Related to Linux' growth in cloud computing is the, well-known success of Linux on supercomputers, both in, the high-performance computing (HPC) and high-availability, (HA) areas, where academic research in physics and, bioengineering, and firms in the financial and energy, , Copyright @ NIMI Not to be Republished
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industries need reliable and scalable computing power to, accomplish their goals., Many of the popular Web 2.0 services on the Internet,, such as Twitter, Linked In, YouTube, and Google all rely, on Linux as their operating system. As new web services, arrive in the future, Linux will increasingly be the platform, that drives these new technologies., , The kernel of the Window operating system (which few, people outside of Microsoft are allowed to look at without, Fig 1, , Current application of Linux operating systems, Today Linux has joined the desktop market. Linux, developers concentrated on networking and services in, the beginning, and office applications have been the last, barrier to be taken down. They don't like to admit that, Microsoft is ruling this market, so plenty of alternatives, have been started over the last couple of years to make, Linux an acceptable choice as a workstation, providing an, easy user interface and MS compatible office applications, like word processors, spreadsheets, presentations and, the like. On the server side, Linux is well-known as a stable, and reliable platform, providing database and trading, services for companies like Amazon, the well-known online, bookshop, US Post Office, the German army and many, others. Especially Internet providers and Internet service, providers have grown fond of Linux as firewall, proxy- and, web server, and you will find a Linux box within reach of, every UNIX system administrator who appreciates a, comfortable management station. In post offices, they are, the nerve centres that route mail and in large search engine,, clusters are used to perform internet searches. These are, only a few of the thousands of heavy-duty jobs that Linux, is performing day-to-day across the world. It is also worth, to note that modern Linux not only runs on workstations,, mid- and high-end servers, but also on "gadgets" like PDA's,, mobiles, a shipload of embedded applications and even, on experimental wristwatches. This makes Linux the only, operating system in the world covering such a wide range, of hardware., The code, Linux is also unique from other operating systems in that, it has no single owner. Torvalds still manages the, development of the Linux kernel, but commercial and, private developers contribute other software to make the, whole Linux operating system., The kernel, All operating systems have kernels, built around the, architectural metaphor that there must be a central set of, instructions to direct device hardware, surrounded by, various modular layers of functionality. The Linux kernel is, unique and flexible because it is also modular in nature., Modularity is desirable because it allows developers to, shed parts of the kernel they don't need to use. Typically, a smaller kernel is a faster kernel, because it isn't running, processes it does not need., If a device developer wants a version of Linux to run on a, cell phone, she does not need the kernel functionality that, deals with disk drives, Ethernet devices, or big monitor, screens. She can pull out those pieces (and others), leaving, just the optimized kernel to use for the phone., , paying for the privilege) is a solidly connected piece of, code, unable to be easily broken up into pieces. It is difficult, (if not impossible) to pare down the Windows kernel to fit, on a phone., This modularity is significant to the success of Linux. The, ability to scale down (or up) to meet the needs of a specific, platform is a big advantage over other operating systems, constrained to just a few possible platforms., Modularity also effects stability and security as well. If, one piece of the kernel code happens to fail, the rest of, the kernel will not crash. Similarly, an illicit attack on one, part of the kernel (or the rest of the operating system), might hamper that part of the code, but should not, compromise the security of the whole device., The environments, The windows, menus, and dialog boxes most people think, of as part of the operating system are actually separate, layers, known as the windowing system and the desktop, environment., These layers provide the human-oriented graphical user, interface (GUI) that enables users to easily work with, applications in the operating system and third-party, applications to be installed on the operating system., In Linux, there a lot of choices for which windowing, system and desktop environment can be used,, something that Linux allows users to decide. This cannot, be done in Windows and it's difficult to do in OS X., Like the operating system and kernel, there are tools and, code libraries available that let application developers to, more readily work with these environments (e.g., gtk+ for, GNOME, Qt for KDE)., The applications, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished, , 61
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Operating systems have two kinds of applications: those, that are essential components of the operating system, itself, and those that users will install later. Closed, operating systems, like Windows and OS X, will not let, users (or developers) pick and choose the essential, component applications they can use. Windows, developers must use Microsoft's compiler, windowing, system, and so on., Linux application developers have a larger set of choices, to develop their application. This allows more flexibility to, build an application, but it does mean a developer will, need to decide which Linux components to use., The distributions, A Linux distribution is a collection of (usually open source), software on top of a Linux kernel. A distribution (or short,, distro) can bundle server software, system management, tools, documentation and many desktop applications in a, central secure software repository. A distro aims to, provide a common look and feel, secure and easy, software management and often a specific operational, purpose., Let's take a look at some popular distributions., Red hat, Red Hat is a billion dollar commercial Linux company that, puts a lot of effort in developing Linux. They have hundreds, of Linux specialists and are known for their excellent, support. They give their products (Red Hat, Enterprise Linux and Fedora) away for free. While Red, , 62, , Hat Enterprise Linux (RHEL) is well tested before release, and supported for up to seven years after release,, Fedora is a distro with faster updates but without, support., Ubuntu, Canonical started sending out free compact discs with, Ubuntu Linux in 2004 and quickly became popular for home, users (many switching from Microsoft Windows). Canonical, wants Ubuntu to be an easy to use graphical Linux desktop, without need to ever see a command line. Of course they, also want to make a profit by selling support for Ubuntu., Debian, There is no company behind Debian. Instead there are, thousands of well organised developers that elect a Debian, Project Leader every two years. Debian is seen as one of, the most stable Linux distributions. It is also the basis of, every release of Ubuntu. Debian comes in three versions:, stable, testing and unstable. Every Debian release is, named after a character in the movie Toy Story., Other, Distributions like Cent OS, Oracle Enterprise Linux and, Scientific Linux are based on Red Hat Enterprise Linux, and share many of the same principles, directories and, system administration techniques. Linux Mint, Edubuntu, and many other ubuntu named distributions are based on, Ubuntu and thus share a lot with Debian. There are, hundreds of other Linux distributions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.24 - 1.5.26, COPA - Dos & Linux Operating System, Handling commands and various editors, Objectives: At the end of this lesson you shall be able to, • know about terminal, • explain the command shell, • list out the directory layout of linux, • define the linux commands, • list out the special characters of linux OS, • explain various editors in linux OS., Starting up a terminal, , Some of the most popular shells are:, , To access the shell we will use a shell-like application,, also called a terminal emulator. There is a huge number, of good terminal applications out there, including the, default ones in GNOME or KDE, or Yakuake, Guake, rxvt, and so on. For now let's just stick with the default that, , • bash - the Bourne-Again Shell, the default shell on, most Linux systems., , • sh - the Bourne Shell, an older shell which is not so, widely used anymore., , Fig 1, , comes with your system. If you're using GNOME you can, access the terminal by going to Applications ->, Accessories -> Terminal or pressing Alt+F2 and typing, gnome-terminal in the run box that appears, followed by, Enter. If you're running KDE you can type instead, console after pressing Alt+F2., Depending on the distribution, the prompt may look something like user@host$. The first part before the ampersand is the login username, and the other one is the, hostname of the computer., Command shell, , • csh - the ‘C’ Shell, which accepts a syntax which, resembles the ‘C’ programming language., , • tcsh - an improved version of the ‘C’ Shell., • ksh - the Korn Shell, initially developed in the early, 1980’s., , • dash - Debian Almquist Shell, a shell created by the, Debian distribution., , Listing of shells available in the system, $ cat /etc/shells/, , A shell is a command interpreter which allows you to, interact with the computer. The way things work is pretty, simple: you type in commands, the shell interprets them,, performs the tasks it was asked to do, and finally it sends, the results to the standard output, which is usually the, screen., This is a list of files inside the root directory. The root, directory is the first location in the file system tree, hierarchy, and it is represented by the slash, character : /., , The above command will display the following output as, on Fig 2., In this tutorial we will focus on Bash, since it is the most, widely used and also one of the most powerful shells out, there. Bash is a modern implementation of the older, Bourne Shell (sh), developed by the GNU project, which, provides a huge amount of tools and which, together with, the Linux kernel, desktop environments like GNOME or, KDE and applications which run on top of them, comprise the whole Linux platform. On a Debian or Ubuntu, distribution, the default shell used by the system is specified in the file /etc/passwd (default being Bash)., 63, , Copyright @ NIMI Not to be Republished
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Fig 2, , How to display default shell in the system, Type the following command in the terminal, $ echo $SHELL, , And press Enter key. The default shell will be displayed, as on Fig 3., , Fig 3, , 64, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The Linux directory layout, Directory, , /bin, /boot, /dev, /etc, /home, /lib, /proc, /root, /sbin, /tmp, /usr, /usr/bin, /usr/include, /usr/lib, /usr/local, , /usr/sbin, /usr/share, /usr/src, /usr/X11R6, /var, , Description, The nameless base of the file system. All other directories, files, drives,, and devices are attached to this root. Commonly (but incorrectly), referred to as the “slash” or “/” directory. The “/” is just a directory, separator, not a directory itself., Essential command binaries (programs) are stored here (bash, ls,, mount, tar, etc.), Static files of the boot loader, Device files. In Linux, hardware devices are accessed just like other, files, and they are kept under this directory., Host-specific system configuration files., Location of users' personal home directories (e.g. /home/Susan)., Essential shared libraries and kernel modules., Process information pseudo-file system. An interface to kernel data, structures, The root (super user) home directory., Essential system binaries (fdisk, fsck, init, etc)., Temporary files. All users have permission to place temporary files here., The base directory for most shareable, read-only data (programs,, libraries, documentation, and much more)., Most user programs are kept here (cc, find, du, etc.)., Header files for compiling C programs., Libraries for most binary programs, “Locally” installed files. This directory only really matters in, environments where files are stored on the network. Locally-installed, files go in /usr/local/bin, /usr/local/lib, etc.). Also often used for, Software packages installed from source, or software not officially, shipped with the distribution., Non-vital system binaries (lpd, useradd, etc.), Architecture-independent data (icons, backgrounds, documentation,, terminfo, man pages, etc.)., Program source code. E.g. The Linux Kernel, source RPMs, etc., The X Window System, Variable data: mail and printer spools, log files, lock files, etc., , What are Linux commands?, Linux commands are executable binary files which can, be ran to perform certain tasks, like for example listing, the files in a directory running an entire graphical application. Examples of frequently used commands are ls,, cd, pwd, date or cat. With the exception of executable, files, there is also a category called shell built-ins, which, are commands provided by the shell itself (Bash in our, case). We'll deal with those later., The general form of a Linux command is:, command options(s) filename(s), Which specifies a command, followed by one or more, parameters, and optionally one or more files to apply it, on. For example:, $ echo -e 'Hello, world!\n', , Will output the text 'Hello, world!' followed by a newline, character. The -e parameter (also called argument, or, switch in this case) tells the echo command to interpret, escaped characters, like the trailing \n, which will add a, newline after the text inside the single quotes. Ignore the, leading dollar sign, it just signifies the shell prompt., A command may or may not have arguments. An argument can be an option or a filename., Special characters in linux operating system, it is important to know that there are many symbols and, characters that the shell interprets in special ways. This, means that certain typed characters: a) cannot be used, in certain situations, b) may be used to perform special, operations, or, c) must be "escaped" if you want to use, them in a normal way., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 65
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Character, , \, , Escape character. If you want to reference a special character, you must, “escape” it with a backslash first., Example: touch /tmp/filename\*, , /, , Directory separator, used to separate a string of directory names., Example: /usr/src/linux, , ., , Current directory. Can also “hide” files when it is the first character in a, filename., , .., , Parent directory, , ~, , User's home directory, , *, , Represents 0 or more characters in a filename, or by itself, all files in a, directory., Example: pic*2002 can represent the files pic2002, picJanuary2002,, picFeb292002, etc., , ?, , Represents a single character in a filename., Example: hello?.txt can represent hello1.txt, helloz.txt, but not, hello22.txt, , [], , Can be used to represent a range of values, e.g. [0-9], [A-Z], etc., Example: hello[0-2].txt represents the names hello0.txt,, hello1.txt, and hello2.txt, , |, , “Pipe”. Redirect the output of one command into another command., Example: ls | more, , >, , Redirect output of a command into a new file. If the file already exists,, over-write it., Example: ls > myfiles.txt, , >>, , 66, , Description, , Redirect the output of a command onto the end of an existing file., Example: echo .Mary 555-1234. >> phonenumbers.txt, , <, , Redirect a file as input to a program., Example: more < phonenumbers.txt, , ;, , Command separator. Allows you to execute multiple commands on a single, line., Example: cd /var/log ; less messages, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The cd command, The cd command is used to change the current directory, (i.e., the directory in which the user is currently working), in Linux and other Unix-like operating systems. It is similar, to the CD and CHDIR commands in MS-DOS., cd's syntax is, cd [option] [directory], The items in square brackets are optional. When used, without specifying any directory name, cd returns the user, to the previous current directory. This provides a convenient, means of toggling between two directories., When a directory name is provided, cd changes the current, directory to it. The name can be expressed as an absolute, pathname (i.e., location relative to theroot directory) or as, a local pathname (i.e., location relative to the current, directory). It is usually more convenient to use a local, pathname when changing to a subdirectory of the current, directory., As an example, the following would change the current, directory, regardless of where it is on the system (because, it is an absolute path), to the root directory (which is, represented by a forward slash):, cd /, Likewise, the following would change the current directory,, regardless of its location, to the /usr/sbin directory (which, contains non-vital system utilities that are used by the, system administrator):, cd /usr/sbin, If a user currently in the directory /usr/local/share/man/, desired to change to the directory /usr/local/share/man/, man2, which is a subdirectory of the current directory, it, would be possible to change by using the absolute, pathname, i.e.,, cd /usr/local/share/man/man2, However, it would clearly be much less tedious to use the, relative pathname, i.e.,, cd man2, On Unix-like operating systems the current directory is, represented by a singledot and its parent directory (i.e.,, the directory that contains it) is represented by two, consecutive dots. Thus, it is possible (and often convenient), to change to the parent of the current directory by using, the following:, cd .., Another convenient feature of cd is the ability for any user, to return directly to its home directory by merely using a, tilde as the argument. A home directory, also called a, login directory, is the directory on a Unix-like operating, system that serves as the repository for a user's personal, files, directories and programs. It is also the directory that, a user is first in after logging into the system. A tilde is a, short, wavy, horizontal line character that represents the, , home directory of the current user. That is, any user can, return immediately to its home directory by typing the, following and then pressing the Enter key:, cd ~, This is easier than typing the full name of the user's home, directory, for instance, /home/josephine in the case of a, user named josephine. (And it is just one of the numerous, shortcuts that help make the command line on Unix-like, operating systems so easy to use.), When followed by a space and then a hyphen, cd both, returns the user to the previous current directory and, reports on a new line the absolute pathname of that, directory. This can further enhance the already convenient, toggling capability of cd. Toggling is particularly convenient, when at least one of the two directories has a long absolute, pathname, such as /usr/local/share/man/man2., cd has only two options, and neither of them are, commonly used. The -P option instructs cd to use the, physical directory structure instead of following symbolic, links. The -L option forces symbolic links to be followed., The pwd command, The pwd command reports the full path to the current, directory., The current directory is the directory in which a user is, currently operating while using a command line interface., A command line interface is an all-text display mode and, it is provided via a console (i.e., a display mode in which, the entire screen is text only) or via a terminal window, (i.e., a text-only window in a GUI)., The full path, also called an absolute path, to a directory, or file is the complete hierarchy of directories from the, root directory to and including that directory or file. The, root directory, which is designated by a forward slash (/),, is the base directory on the filesystem (i.e., hierarchy of, directories), and it contains all other directories,, subdirectories and files on the system. Thus, the full path, for any directory or file always begins with a forward slash., pwd is one of the most basic commands in Linux and, other Unix-like operating systems, along with ls, which is, used to list the contents of the current directory, andcd,, which is used to change the current directory., pwd's syntax is, pwd [option], Unlike most commands, pwd is almost always used just, by itself, i.e.,, Pwd, That is, it is rarely used with its options and never used, with arguments (i.e., file names or other information, provided as inputs). Anything that is typed on the same, line after pwd, with the exception of an option, is ignored,, and no error messages are returned., As an example, if a user with the username janis is in its, home directory, then the above command would typically, return /home/janis/ (because, by default, all home, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 67
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directories are located in the directory /home). Likewise,, if a user were currently working in directory /usr/share/, config (which contains a number of programconfiguration, files), then the same command would return /usr/share/, config., pwd is useful for confirming that the current directory has, actually been changed to what the user intended after, using cd. For example, after issuing the cd command to, change the current directory from /home/janis to /usr/share/, config, pwd could be used for confirmation; that is, the, following sequence of commands would be issued:, cd /usr/share/config/, pwd, The standard version of pwd has a mere two options, both, of which are employed only infrequently. The --help option, is used as follows:, pwd --help, This option displays information about pwd, of which there, is very little because it is such a simple command (i.e., it, only has two options and accepts no arguments)., The other option is --version, which displays the version, number, i.e.,, pwd --version, Although it is often thought of as standing for present, working directory, pwd is actually an acronym for print, working directory. The word print is traditional, UNIXterminology for write or display, and it originated when, computer output was typically printed on paper by default, because CRT (cathode ray tube) display monitors were, not yet widely available., The echo command, echo is a built-in command in the bash and C shells that, writes its arguments to standard output., A shell is a program that provides the command line (i.e.,, the all-text display user interface) on Linux and other Unixlike operating systems. It also executes (i.e., runs), commands that are typed into it and displays the results., bash is the default shell on Linux., A command is an instruction telling a computer to do, something. An argument is input data for a command., Standard output is the display screen by default, but it, can be redirected to a file, printer, etc., The syntax for echo is, $ echo $USER, $ echo "Hello world", The items in square brackets are optional. A string is any, finite sequence of characters (i.e., letters, numerals,, symbols and punctuation marks)., When used without any options or strings, echo returns a, blank line on the display screen followed by the command, prompt on the subsequent line. This is because pressing, the ENTER key is a signal to the system to start a new, 68, , line, and thus echo repeats this signal., When one or more strings are provided as arguments,, echo by default repeats those stings on the screen. Thus,, for example, typing in the following and pressing the ENTER, key would cause echo to repeat the phrase This is a pen., on the screen:, echo This is a pen., It is not necessary to surround the strings with quotes, as, it does not affect what is written on the screen. If quotes, (either single or double) are used, they are not repeated, on the screen., Fortunately, echo can do more than merely repeat verbatim, what follows it. That is, it can also show the value of a, particular variable if the name of the variable is preceded, directly (i.e., with no intervening spaces) by the dollar, character ($), which tells the shell to substitute the value, of the variable for its name., For example, a variable named x can be created and its, value set to 5 with the following command:, x=5, The value of x can subsequently be recalled by the following:, echo The number is $x., Echo is particularly useful for showing the values of, environmental variables, which tell the shell how to behave, as a user works at the command line or in scripts(short, programs)., For example, to see the value of HOME, the environmental, value that shows the current user's home directory, the, following would be used:, echo $HOME, Likewise, echo can be used to show a user's PATH, environmental variable, which contains a colon-separated, list of the directories that the system searches to find the, executable program corresponding to a command issued, by the user:, echo $PATH, echo, by default, follows any output with a newline, character. This is a non-printing (i.e., invisible) character, that represents the end of one line of text and the start of, the next. It is represented by \n in Unix-like operating, systems. The result is that the subsequent command, prompt begins on a new line rather than on the same line, as the output returned by echo., The -e option is used to enable echo's interpretation of, additional instances of the newline character as well as, the interpretation of other special characters, such as a, horizontal tab, which is represented by \t. Thus, for, example, the following would produce a formatted output:, echo -e "\n Projects: \n\n\tplan \n\tcode \n\ttest\n", (The above command should be written on a single line,, although it may render as two lines on smaller display, screens.) The -n option can be used to stop echo from, adding the newline to output., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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By making use of output redirection, echo provides a very, simple way of creating a new file that contains text. This, is accomplished by typing echo followed by the desired, text, the output redirection operator (which is a rightward, pointing angle bracket) and finally the name of the new, file. The file can likewise be formatted by using special, characters. Thus, for example, the formatted output from, the above example could be used to create a new file, called project1:, , Date command, , echo -e "\n Project1: \n\n\tplan \n\twrite \n\ttest\n" >, project1, , 01:13:14, , The contents of the new file, including any formatting, can, be verified by using a command such as cat or less, i.e.,, , Display current time and date., $ date, Fri Jul 6 01:07:09 IST 2012, If you are interested only in time, you can use 'date +%T', (in hh:mm:ss):, $ date +%T, tty command, Displays current terminal., $ tty, , less project1, echo can likewise be a convenient way of appending text, to the end of a file by using it together with the the append, operator, which is represented by two consecutive rightward, pointing angle brackets. However, there is always the risk, of accidentally using a single bracket instead of two,, thereby overwriting all of the contents of the file, and thus,, this feature is best reserved for use in scripts., echo can also be used with pattern matching, such as the, wildcard character, which is represented by the star, character. For example, the following would return the, phrase The gif files are followed by the names of all the .gif, image files in the current directory:, echo -e The gif files are *.gif, , /dev/pts/0, whoami command, This command reveals the current logged in user., $ whoami, raghu, id command, This command prints user and groups (UID and GID) of, current user., $ id, uid=1000(raghu) gid=1000(raghu), groups = 1000 (raghu), 4(adm), 20(dialout), 24(cdrom),, 46(plugdev), 112(lpadmin), 120(admin),122(sambashare), , The cal command, Displays calendar of current month., , By default information about current user is displayed. If, another username is provided as an argument, information, about that user will be printed:, , $ cal, July 2012, , $ id root, , Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , Clear command, , 15, , 16, , 17, , 18, , 19, , 20, , 21, , This command clears the screen., , 22, , 23, , 24, , 25, , 26, , 27, , 28, , Getting help command, , 29, , 30, , 31, , 'cal ' will display calendar for specified month and year., $ cal 08 1991, August 1991, Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , uid=0(root) gid=0(root) groups=0(root), , For all its advantages, a big disadvantage of command, line is that there are a lot of commands and even more are, their options and usage. But nobody can remember all, commands. There are some smarter ways of using, command line. Linux provides us with several such, resources discussed here:, --help option, With almost every command, '--help' option shows usage, summary for that command., , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , 15, , 16, , 17, , $ date --help, , 18, , 19, , 20, , 21, , 22, , 23, , 24, , Usage: date [OPTION]... [+FORMAT], , 25, , 26, , 27, , 28, , 29, , 30, , 31, , or: date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]], Display the current time in the given FORMAT, or set the, system date., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 69
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The whatis command, , $ info date, , The whatis command provides very brief descriptions of, command line programs (i.e., all-text mode programs) and, other topics related to Linux and other Unix-like operating, systems., It accomplishes this by searching the short descriptions, in the whatis database for each keyword provided to it as, an argument (i.e., input data). This database contains just, the title, section number and description from the NAME, section of each page in the man manual that is built into, most Unix-like systems., The syntax for whatis is:, whatis keyword(s), For example, the following provides a single line summary, of the headcommand (which by default displays the first, ten lines of each file that is provided to it as an argument):, whatis head, whatis can be used to simultaneously search for information, about multiple topics. For example, the following would, provide information about both head and tail (which by, default reads the final ten lines of files):, whatis head tail, The output of whatis is limited by the fact that it provides, only a single line for each keyword found in the database;, thus it supplies incomplete information about even, moderately complex commands. For example, the, following use of whatis to obtain information about the cat, command generates the output "concatenate files and print, on the standard output":, whatis cat, However, this omits some important information about cat,, particularly the facts that it is very convenient to use for, reading files and that it is also used to create and write to, files., whatis is similar to the apropos command. However,, apropos is more powerful in that its arguments are not, limited to complete words but can also be strings (i.e.,, any finite sequences of characters) which comprise parts, of words. Both commands are unusual in that they have, no options., The man command (which is used to read the built-in, manual pages), when used with its -f option, produces the, same output as whatis. Thus, for example,, man -f cat, is equivalent to, whatis cat, Info pages, , Word processors in the Linux environment, Text editors are used by many different types of people., Casual users, writers, programmers, and system, administrators will all use a text editor at one time or another, in Linux., Use of text editor, A text editor is just like a word processor without a lot of, features. All operating systems come with a basic text, editor. Linux comes with several. The main use of a text, editor is for writing something in plain text with no formatting, so that another program can read it. Based on the, information it gets from that file, the program will run one, way or another., vi Editor, "vi" (pronounced "vee eye") is a text editor with a, deceptively simple appearance that belies its great power, and efficiency. New users soon realize that there is far, more to this little program than meets the eye., vi, or one of its clones, is found in almost every version of, Linux and Unix, and, in fact, it is the only editor that is, available in virtually every Unix installation., History of vi, The vi editor was developed starting around 1976 by Bill, Joy, who was then a graduate student at the University of, California at Berkeley. Joy later went on to help found Sun, Microsystems and became its Chief Scientist., "ed" was the original Unix text editor. Like other early text, editors, it was line oriented and used from dumb printing, terminals. Joy first developed "ex" as an improved line, editor that supported a superset of ed commands. He then, developed vi as a "visual interface" to ex. That is, it allows, text to be viewed on a full screen rather than only one line, at a time. vi takes its name from this fact., vi remains very popular today in spite of the development, and widespread availability of GUI (graphical user interface), mode text editors which are far more intuitive and much, easier for beginners to use than text-mode text editors, such as vi. GUI-mode text editors include gedit and Emacs,, both, of, which, have, become, very, common on Linux and other Unixes today., Features of vi, , • It is present in almost every Linux Unix system, even, the most minimal., , • It is very small. In fact, some versions have a total, , code size of less than 100KB. This makes it easy to, include vi on even the tiniest versions of Linux, such as, those in embedded systems and those that run from a, single floppy disk., , Info documents are sometimes more elaborated than man, pages. But for some commands, info pages are just the, • It is typist-friendly, at least once you get used to it. For, same as man pages. These are like web pages. Internal, example, the commands are very short, usually just a, links are present within the info pages. These links are, few keystrokes. And because vi does not use the, called nodes. info pages can be navigated from one page, mouse, there is never any need to remove one's hands, to another through these nodes., 70, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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from the keyboard. This can speed up editing, substantially., , changes, hit ESC, type :q! and then press ENTER. This, is sometimes referred to as a "forced quit.", , • It is very powerful, as just a few very short commands, , vi works with a buffer (a block of memory in the RAM, chips). When you open an existing file, vi copies that file, from the hard disk (or floppy, CDROM, etc.) to a buffer. All, changes that you make to a file are initially made only to, the copy in the buffer, and they are only made to the file, itself when you "save" your changes. "Saving" a file means, writing (i.e., transferring) the contents of the buffer to the, hard disk (or floppy disk)., , can make sweeping changes to large documents. In, fact, vi is more powerful than most of its users realize,, and few of them know more than just fraction of all the, commands., , Opening and closing file, vi can be used both when your system is in text mode, (the entire screen is devoted to text and there are no, images) and when your system is in GUI mode (the screen, contains windows, images and menus). When it is in GUI, mode (usually KDE or Gnome), vi runs in a terminal window., A terminal window is a text-only window, and it can usually, be opened by clicking on an icon (small image) of a, computer screen., (In the case of Red Hat Linux, the terminal window can be, opened by clicking on the icon of a red hat in the lower left, hand corner of the screen, opening the System Tools menu, and then selecting Terminal from that menu. It can be, convenient to add the icon for the terminal window to the, launcher panel along the bottom of the screen, if it is not, already there.), There are at least two ways to use vi to simultaneously, create and open a new file. One is by just typing vi at the, command line, like this:, vi, This creates an empty file that will not have a name until, you save its contents to disk (i.e., transfer the text you, typed into it to your hard disk, floppy disk, etc. for long, term storage)., A second way to open a new file is by typing vi followed by, the name of the file to be created, for example:, vi apple, This creates a new file named "apple" in the current, directory (the directory or folder which is currently open, on your all-text screen or your terminal window)., If you want, it could create the same file with an extension, such as ".txt" added to the end of the file name. In Linux, this is merely a matter of convenience (or habit), and it, generally makes no real difference for the file because it, remains a plain text file in either case. For example:, vi apple.txt, To close a file to which no changes have been made, hit, ESC (the Esc key, which is located in the upper left hand, corner of the keyboard), then type :q (a colon followed by, a lower case "q") and finally press ENTER. (The term "hit", is used here instead of "press" to emphasize that it is not, necessary to keep the ESC key held down but just to, press it momentarily.), To close a file to which changes have been made (such as, text having been added or removed) without saving the, , Likewise when you open a new file. All text you enter (and, subsequent edits you make to it) exists only in the buffer, until you save the file to disk., To save the changes that have been made to a file, hit, ESC, type :qw and then press ENTER. The "w" stands for, "write." An alternative, and perhaps easier, way to save a, file and quit at the same time is to hit ESC and then type, ZZ (two capital Z's in succession)., After you have created a new text file and closed it, you, might want to confirm that nothing went wrong and that, the file actually exists. Probably the simplest way to do, this is to use the standard Unix ls command, which, displays a list of all of the files in the current directory., Entering text, vi has two basic modes of operation: command mode and, text insert mode. How to switch back and forth, between them is probably the most confusing thing about, vi for beginners. But it is actually very simple, and once, you get used to it you might also find it quite efficient., Command mode is the default mode when a file (existing, or new) is opened. (This is the opposite of most text and, word processors and therefore may seem counter-intuitive.), Because every file opens initially in command mode, you, can not immediately begin typing text. That is, everything, that is typed on the keyboard is interpreted by vi to be a, command., Examples of the many types of commands can perform, on a file while in command modes are:-, , • Switching to text insert mode., • Moving the cursor around the file., • Deleting characters or lines., • Transposing characters., • Changing case., • Appending the contents of the file to another (closed), file., , • Setting vi options., • Saving the file to disk., • Closing the file and quitting vi., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 71
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The other mode, text insert mode, is also referred to as, simply "insert mode" or "input mode." It is used for entering, text into the buffer memory (and simultaneously onto the, screen). In this mode everything that is typed on the, keyboard is added to the text and does not become a, command (although you can perform some command, operations in text mode with vi clones)., , There will be times when it need to place a character to, the right of the character under the cursor. This is, particularly useful when the cursor is over the last character, in a line and you want to append the line. To do this,, simply use the a (lower case "a," which stands for "append"), command instead of the i command to switch from, command mode into insert mode., , The most common way to switch from command mode to, the input mode is to use the i (which stands for "insert" or, "input") command. This is accomplished by simply typing, the letter i while in command mode. Now you are ready to, start typing text., , After it have saved a file that have created or modified, using vi, might want to verify that its contents are really, what you had intended. One way to do this is to use cat,, the Unix concatenation utility. (No, this has no relationship, to the popular domesticated animal whose name has the, same spelling). For example, type:, , Unlike word processors and even most word editors, there, is no automatic word wrap in the traditional version of vi, (although you will notice it in some clones). New lines are, started by pressing ENTER., When finished typing text or need to perform some other, operation such as moving to a different position in the text, or deleting some of it, hit ESC in order to return to the, command mode., Once you have typed some text, you can use the four, basic commands for moving the cursor around the text., These commands enable you to go to any desired location, in order to modify the text, including making insertions, and deletions. The four basic cursor positioning commands, are:, h move cursor one character to left, j move cursor one line down, k move cursor one line up, l move cursor one character to right, Each of these commands can be either used by itself or, modified by typing an integer in front of it to indicate the, number of characters or lines to move. For example, typing, (in command mode, of course), 3j - will move the cursor down three lines. Or typing 2h will, move it two characters to the left., These commands can be repeated by holding the key, down. If attempting an impossible movement, such as, pressing k when the cursor is on the top line, the screen, might flash or a beeping sound might be made (depending, on how your computer is set up)., The cursor can be moved directly to any desired line by, using the G command preceded by the line number. For, example, typing, 5G - moves the cursor to the fifth line from the top of the, text. Just typing G without any number moves the cursor, to the final line of text., When you switch from command mode to input mode, with the i command and then start typing text, each, character you type is placed to the left of the character, covered by the cursor. This causes the character covered, by the cursor as well as everything to its right to be shifted, to the right., 72, , cat /home/john/fruit/lemon, Editing Text, vi offers a rich assortment of commands for editing text., Among the most basic are those used for deleting or, erasing., The x (lower case "x") command deletes the character, immediately under (i,e., covered by) the cursor. To delete, any desired character, just switch to the command mode, (if you are not already there) and then use an appropriate, combination of the h, j, k and l commands (of course, one, at a time) to move the cursor to that character. Then type, x and the character is deleted., By pressing x continuously instead of just hitting it once,, the cursor continuously moves to the right and each, character under it is successively deleted., The X (upper case "X") command is similar except that it, deletes the character to the left of the cursor rather than, the character under it., There are several additional commands for deleting text., The D (upper case "D") command removes the text on the, current line from the character under the cursor to the end, of the line., The d (lower case "d") command is very flexible because, it can be modified to delete any number of characters,, words or lines. Typing d by itself will not do anything, but, typing dw causes the character the cursor is resting on, and the remaining characters to the right of it in the same, word to be deleted. (The "w" stands for "word."), Typing 2dw causes the character under the cursor, the, remaining characters to the right of it in the same word, and all of the characters in the next word to be deleted., For example, typing 2dw with the cursor on the "a" of the, string "pineapple plantation" causes the string "apple, plantation" to be deleted., As another example, typing 3dw with the cursor on the "j", of the string "the bluejay flew south" causes the string, "jay flew south" to be deleted. That is, "jay" and two words, to the right of it are deleted., Deleting an entire line can be accomplished with the dd, command. This command can also be used to delete, multiple lines by preceding it with an integer representing, the number of lines to be removed. For example, typing, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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2dd will delete two consecutive lines beginning with the, current line., , lines can be transposed with the ddp command by placing, the cursor on the upper line and typing ddp., , With some terminals, deletion of a line causes it to be, replaced on the screen with an "@" character. This, character merely represents an empty line and is not, inserted into the text. Its purpose is to relieve the processor, from having to redraw the screen (i.e., change the whole, screen). This character can be removed if desired by typing, r (or l on some terminals) while holding down the CTRL, key., , It is also a simple matter to change the case of a letter., When the cursor is over the desired letter, hit the "~" (tilde), key. This will change a capital letter to a small letter and, visa versa., , The change command c (lower case "c") differs from the, delete command in that it not only deletes a section of, text but also activates insert mode to allow you to type in, replacement text. After you have completed typing in the, replacement text, be sure to press ESC to return to the, command mode., As is the case with d, the c command is not used by itself, but is only used in combination with another letter after it, and an optional integer before it., For example, the command cw (which stands for "change, word") deletes the characters in the current word under, and to the right of the cursor and then switches vi to the, insert mode so that you can enter text to replace the deleted, characters. The number of new characters typed in can, be the same as, fewer or more than the number deleted., The amount of text to be changed can be increased by, preceding the command with a number. For instance, typing, 2cw will additionally remove the next word for replacement, with whatever is typed in. The space between the words is, not preserved., The d and c commands can also be modified by other, characters in addition to "w." For example they can be, used with "b," which stands for "back." Thus, typing3bd, will delete the characters to the left of the cursor in the, current word together with the two words to the left of the, current word., The cc command erases the current line, leaving it blank, and awaiting replacement text. Preceding this command, with an integer will delete that number of lines, beginning, with the current line. For example, typing 5cc will allow, you to change five consecutive lines starting with the current, line., Another change command, R, differs from the c commands, in that it does not initially delete anything. Rather, it, activates insert mode and lets you replace the characters, under the cursor one at a time with characters that you, type in., vi supports several types of transposition. Transposing the, order of two adjacent characters is easy with the xp, command. Just place the cursor on the left-most of the, two characters, type x to erase the left character and then, type p for the deleted character to be put to the right of the, cursor., Two adjacent words can be transposed with the deep, command. To use it, position the cursor in the space just, to the left of the word on the left and type deep. Two adjacent, , The J (upper case "J") command is used to join the next, line to the current line. The opposite operation, splitting a, line, is accomplished in insert mode by merely positioning, the cursor over what will be the first character of the new, line and then hitting ENTER., vi also has an undo capability. The u (lower case "u"), command is used to reverse the effects of an already issued, command that has changed the buffer, but which is not, yet written to disk. U (upper case "U") undoes all of the, changes that have been made to the current line during, your current visit to it, Searching Text, vi also has powerful search and replace capabilities. To, search the text of an open file for a specific string, (combination of characters or words), in the command, mode type a colon (:), "s," forward slash (/) and the search, string itself. What you type will appear on the bottom line, of the display screen. Finally, press ENTER, and the, matching area of the text will be highlighted, if it exists. If, the matching string is on an area of text that is not currently, displayed on the screen, the text will scroll to show that, area., The formal syntax for searching is:, :s/string, For example, suppose you want to search some text for, the string "cherry." Type the following and press ENTER:, :s/cherry, The first match for "cherry" in your text will then be, highlighted. To see if there are additional occurrences of, the same string in the text, type n, and the highlight will, switch to the next match, if one exists., The syntax for replacing one string with another string in, the current line is, :s/pattern/replace/, Here "pattern" represents the old string and "replace", represents the new string. For example, to replace each, occurrence of the word "lemon" in a line with "orange,", type:, :s/lemon/orange/, The syntax for replacing every occurrence of a string in, the entire text is similar. The only difference is the addition, of a "%" in front of the "s":, :%s/pattern/replace/, Thus repeating the previous example for the entire text, instead of just for a single line would be:, :%s/lemon/orange/, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 73
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Working with multiple files, It is easy to insert text into an open file from another file., All that is necessary is to move the cursor to the location, where you want the text inserted, then type, :r filename, where "filename" is the name of the file to insert., For example, if you want to copy the contents of the file, "peach" into the file "fruit," you would first position the, cursor to the desired line in "fruit" and then type, :r peach, Notice that this operation causes no change to the file, "peach.", , vi +3 apple, Use of the + command without any modifying number, opens a file with the cursor positioned on the last line of, text. This can save some keystrokes when you want to, open a file just to append data to the end of it. For example:, vi + apple, You have already learned several commands for switching, from command mode to insert mode, including i for, inserting to the left of the cursor position, a for inserting to, the right of the cursor position and the c commands for, changing text. A more complete list is as follows:, a, , appends after current cursor position., , A, , appends at end of current line., , c, , starts a change option., , C, , starts a change option from current position, to end of current line., , i, , inserts to the left of the cursor position., , I, , inserts at start of line., , o, , cursor moves to new, blank line below its, current position., , This allows you to edit "apple" first. After saving "apple,", typing :n calls up "pear" for editing., , O, , cursor moves to new, blank line above its, current position., , If you want to simultaneously open all files in the current, directory, just type vi * (vi + space + asterisk)., , R, , replaces characters one at a time., , Additional operations, , A simple way to obtain basic information about any file, that is currently open, including name, size and the current, line number, is to hold down CTRL and type g. This data, appears on the bottom line of the display., , You can also append text from the currently open file to, any other file. This is accomplished using the :w (colon +, "w") command followed without a space by >>. For, example, to append the contents of a currently open file, named "pear" to the file named "apple," type, :w>> apple, At times it can be convenient to open multiple files, simultaneously. This is efficiently accomplished by just, listing all of the files to be opened after the vi command., For example, to simultaneously open files about three kinds, of fruit, type:, vi apple pear orange, , As you have learned, creating and opening files in vi can, be a very simple matter. However, many combinations of, options are available that can add much power and, flexibility for these tasks, as can be seen by looking at, the full syntax for opening files:, vi [flags] [cmd] [filename], The square brackets ([ ]) around each section of arguments, (modifiers) of the command indicates that they are optional., (That is, a file can be opened by just typingvi alone or by, typing it with any combination of the three arguments. For, instance, the example of vi dog contains only the, mandatory vi and the optional third argument, which is the, name of the file to open.), , Summary of commands, The following list contains the basic commands presented, in the first eight pages of this tutorial along with occasional, examples of usage (shown in parenthesis). They are, presented in roughly the same order in which they appear, in the tutorial. (All commands that begin with a colon are, followed by ENTER.), , As only one of many possible examples of adding options, for opening files, an existing file can be opened with the, cursor appearing on any desired line instead of just on the, first line. (One situation in which this can be particularly, useful is if your file is part of a program which you are, writing and the compiler reports an error on a specific line, in that file.) This is accomplished by adding the + (plus, sign) command followed the desired line number. For, example, to open the file "apple" with the cursor located, on the third line, type:, 74, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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vi, vi *, , typed at the command line to open one or more files in the same directory, (vi tomato.txt opens a file named "tomato.txt" in the current directory), (vi parsley sage rosemary opens the three files "parsley," "sage" and, "rosemary" in the current directory), typed at the command line to open every file in the current directory, , :q, , closes (quits) a file to which no changes have been made, , :q!, , quits without saving any changes, , :w, , writes (i.e., saves) the current file to disk, , :wq, ZZ, i, h, , writes the buffer contents to disk (i.e., saves changes) and quits, same as :wq, activates text insert mode, inserting text immediately under the current, position of the cursor., moves the cursor one character to the left, (2h moves the cursor two characters to the left), , j, , moves the cursor one line down, (3j moves the cursor three lines down), , k, , moves the cursor one line up, , l, , moves the cursor one character to the right, , G, , moves the cursor to the desired line; moves the cursor to the last line of text, if not preceded by a modifying integer, (5G moves the cursor to the fifth line), , a, , switches to insert mode and allows insertion of text immediately to the right, of the cursor., , x, , deletes the character immediately under the cursor, (xxx deletes the character immediately under cursor and then deletes the, two characters to its right), , X, , deletes a single character to the left of cursor, , D, , removes the text on the current line from the character under the cursor to, the end of the line, , dw, , deletes the character immediately under the cursor and the remaining, characters to the right of it in the same word, (2dw deletes the character immediately under the cursor, the remaining, characters to the right of it in same word and all of the next word), , dd, , deletes the entire line containing the cursor, and the cursor then moves to, the next line, (2dd deletes two consecutive lines beginning with the current line), , cw, , deletes the character under the cursor and to its right in the same word and, allows new characters to be typed in to replace them, (2cw deletes the character under the cursor and to its right in the same, word and in the next word, and then allows replacement characters to be, typed in), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 75
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cc, , erases the current line and allows replacement text to be typed in, (2cc erases the current line and the next line and allows replacement text to, be typed in for both lines), , cb, , deletes the characters to the left of the cursor in the current word and allows, replacement characters to be typed in, (3cb deletes the characters to the left of the cursor in the current word, together with the two words to its left and then allows replacement text to be, typed in), , R, , activates text input mode allowing text under and to the right of the cursor to, be overwritten one character at a time, , xp, , transposes two adjacent characters, , deep, ddp, , transposes two adjacent lines, , ~, , changes case of the character under the cursor, , J, , joins the current line with the next line, , u, , reverses the effects of the most recent command that has changed the buffer, , U, , undoes all changes made to the current line during the current visit to it, , :s/, n, :s/ / /, , :%s/, //, , 76, , transposes two adjacent words, , searches the text for the first instance of a designated string, (:s/cucumber searches the text for the first instance of the string, "cucumber"), searches the text for the next instance of a designated string, replaces the first instance of a designated string, (:s/cucumber/radish/ replaces the first instance of the string "cucumber" with, the string "radish"), replaces every instance of a designated string, (:%s/cucumber/radish/ replaces every instance of the string "cucumber" with, the string "radish"), , :r, , inserts text into the currently open file from another file, (:r lettuce.txt inserts text into the currently open file from the file named, "lettuce.txt"), , :w>>, , appends the text from the currently open file into another file, (:w>> cabbage appends the text from the currently open file into the file, named "cabbage"), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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pico editor, , offered as the default in subsequent searches., , pico is a simple text editor in the style of the pine, composer., , Blocks of text can be moved, copied or deleted with, creative use of the command for mark (Ctrl-^), delete, (Ctrl-k) and undelete (Ctrl-u). The delete command will, remove text between the "mark" and the current cursor, position, and place it in the "cut" buffer. The undelete, command effects a "paste" at the current cursor, position., , Syntax, pico [ options ] [ file ], Description, pico is a simple, display-oriented text editor based on the, pine message composer. As with pine, commands are, displayed at the bottom of the screen, and context-sensitive, help is provided. As characters are typed they are, immediately inserted into the text., Editing commands are entered using control-key, combinations. As a work-around for communications, programs that swallow certain control characters, you can, emulate a control key by pressing ESCAPE twice, followed, by the desired control character. For example, "ESC ESC, c" would be equivalent to entering a ctrl-c. The editor has, five basic features: paragraph justification, searching, block, cut/paste, a spelling checker, and a file browser., Paragraph justification (or filling) takes place in the, paragraph that contains the cursor, or, if the cursor is, between lines, in the paragraph immediately below., Paragraphs aredelimited by blank lines, or by lines, beginning with a space or tab. Unjustification can be done, immediately after justification using the control-U key, combination., String searches are not sensitive to case. A search, begins at the current cursor position and wraps around, the end of the text. The most recent search string is, To, , The spell checker examines all words in the text. It then, offers each misspelled word for correction while highlighting, it in the text. Spell checking can be cancelled at any time., Alternatively, pico will substitute for the default spell, checking routine a routine defined by the SPELL, environment variable. The replacement routine should read, standard input and write standard output., The file browser is offered as an option in the "Read File", and "Write Out" command prompts. It is intended to help, in searching for specific files and navigating directory, hierarchies. Filenames with sizes and names of directories, in the current working directory are presented for selection., The current working directory is displayed on the top line, of the display while the list of available, commands takes up the bottom two. Several basic file, manipulation functions are supported: file renaming,, copying, and deletion., Movement commands:, Depending on your system, the arrow keys or the, backspace key may not work. Instead, you can use these, commands to perform the same tasks., , Hold down Ctrl key and press, , Delete a character, , backspace, , Instead of, backspace, , Move up a line, , p, , up arrow, , Move down a line, , n, , down arrow, , Move left one space, , b, , left arrow, , Move right one space, , f, , right arrow, , Move to the end of line, , e, , end, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 77
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Some pico editor options, , ^K Cut text, , ^C Cancel allows you to stop a process at any time. If, you make a mistake, just hold down the Ctrl key and, press c., , Cut a line of text. This option allows you to cut a full line, of text. By using the uncut command and your arrow, keys, you can then paste the cut text at another location, in your document. To cut specific text in a line or to cut, several lines of text, first select the text (see Selecting, Text on the next page)., , ^G get help, Get clear and concise assistance from the Pico help, in, case something unexpected happens or you need, additional information about a command., ^X Exit, , Selecting text, To select text for cutting and pasting use the following, steps:, , Exit Pico at anytime. If made changes to a file or worked, on a new file, but you havent saved the changes, you see, this message:, , Move the cursor to the beginning of the text to select, , Save modified buffer (ANSWERING "No" WILL DESTROY, CHANGES) (y/n)?, , Use the right arrow key or hold down Ctrl and press f to, highlight text, , Answering no (press n) will close Pico and bring you back, to the prompt without saving your file., , When you have highlighted the appropriate text, hold down, the Ctrl key and press k to cut it., , Answering yes (press y) will allow you to save the file, you've been working on (see Write Out section below for, details)., , Paste the text you cut, anywhere in your document, using, UnCut Text, , ^O WriteOut, Save the file without hassles or worries. Fill in the name, of the file beside the File Name to write: prompt. If the file, already has a name, then press enter., ^T To Files option lets to save the text over a file that, exists in the directory. By choosing the To Files option,, Pico takes you to a directory Browser., ^R Read File, Insert text from another file into your current text file. This, option allows you to search through your directories for a, file that you would like to add to your text. This option is, especially handy if you've saved a document and would, like to add its content to the new file you're working on., Text from the file you select is placed on the line directly, above your cursor., At the Insert file : prompt you may either type a file name, or use the Browser options., ^T To Files option lets you import a text file directly into, the file you're currently typing. By choosing the To Files, option, Pico takes you to a directory Browser., ^Y Prev Pg, Move quickly to the previous page. Although you could, just as easily press the up arrow key several times, this, command quickly jumps your cursor up one page., ^V Next Pg, Move quickly to the next page. Although you could just, as easily press the down arrow key several times, this, command quickly jumps your cursor down one page., 78, , Hold down the Ctrl key and press ^, , ^U UnCut Text, Paste text that previously cut. if use this option to undo, an accidental cut of text or place cut text at another location, in the document. The text you cut is pasted on the line, directly above the cursor., ^C Cur Pos, Indicate the current position of the cursor, relative to the, entire document. This is a helpful option if you'd like to, check exactly where in the document. The status line, indicates the following items:, [line 8 of 18 (44%), character 109 of 254 (42%)], ^J Justify, Even out lines of text. This command is handy when, accidentally type extra spaces between words or press, the key before reaching the end of a line. The option, evens the length of text lines automatically., ^U UnJustify, UnJustify lines of text. For the messy line look you can, always select the UnJustify option., ^W Where is, Find a particular string of text quickly. This option allows, you to do a word search in your text. This option is, especially handy for longer documents. If the word you, designated at the Search: prompt is found, it places the, cursor beside it., ^T To Spell, Check for spelling errors. The spell check option allows, to correct spelling errors throughout the document. If spell, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
Page 347 : checker finds a misspelled word or a word it doesn't, recognize (don't worry, this rarely happens), it will correct, the word. At the Edit a replacement: prompt, type in the, correct spelling of a word. However, if you don't want to, make any changes, simply press the enter key., Any words that have corrected but re-occur in the document, can be automatically replaced. At the Replace a with b?, [y]: prompt press y to replace all occurrences of the, misspelled word or n to ignore., Pine Editor, pine is a program for accessing email and newsgroups., Syntax, pine [options] [address, address], Description, pine is a screen-oriented message-handling tool. In its, default configuration, pine offers an intentionally limited, set of functions geared toward the novice user, but it also, has a growing list of optional power-user and personalpreference features. pine's basic feature set includes:, , • View, Save, Export, Delete, Print, Reply and Forward, messages., , • Compose messages in a simple editor (pico) with wordwrap and a spelling checker. Messages may be, postponed for later completion., , • Full-screen selection and management of message, folders., , • Address book to keep a list of long or frequently-used, , addresses. Personal distribution lists may be defined., Addresses may be taken into the address book from, incoming mail without retyping them., , • New mail checking and notification occurs, automatically., , • Context-sensitive help screens., pine supports MIME (Multipurpose Internet Mail, Extensions), an Internet Standard for representing, multipart and multimedia data in email. pine allows you to, save MIME objects to files, and in some cases, can also, initiate the correct program for viewing the object. It uses, the system's mailcap configuration file to determine what, program can process a particular MIME object type. pine's, message composer does not have multimedia capability, , itself, but any type of data file (including multimedia) can, be attached to a text message and sent, using MIME's encoding rules. This allows any group of, individuals with MIME-capable mail software to exchange, formatted documents, spread-sheets, image files, etc, via, Internet email., pine uses the "c-client" messaging API to access local, and remote mail folders. This library provides a variety of, low-level message-handling functions, including drivers for, a variety of different mail file formats, as well as routines, to access remote mail and news servers, using IMAP, (Internet Message Access Protocol) and NNTP (Network, News Transport Protocol). Outgoing mail is usually handed, off to the send mail program but it can optionally be posted, directly via SMTP., Examples, Pine, Launch pine., pine
[email protected], Launch pine, and immediately begin composing an email, addressed to
[email protected]., Joe editor, 'joe'- sounds like a comic strip. Actually, they are two other, text editors that I like and I think are a little easier to, manage. They're like 'vi' in that you use them to create, and edit non-formatted text, but they're a little more userfriendly. Using 'joe' 'joe' was created by Joseph Allen, so, that's why it's called Joe., The majority of joe's commands are based on the CTRL-K, keys and a third key. The most important of these is CTRLK-H which gets 'help'. Help shows the key combinations, to use with 'joe'., The most important thing about 'joe' is the logical concept, that you can just start writing if you want. Try writing, anything you want., To save it, press CTRL-K-D. To save and quit, CTRL-K-X., To quit without saving, CTRL-C, (without the K)., The feature of 'joe' is that if edit a file again, it will save the, previous file with a tilde on the end, like 'tryjoe~' That little, tilde file has saved times. 'joe' is a very good option for, writing those short text files., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 79
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IT & ITES, Related Theory for Exercise 1.5.27 & 1.5.28, COPA - Linux Operating System, Managing files and directories, Objectives: At the end of this lesson you shall be able to, • define manipulating files and directories, • define basic file commands, • explain other file commands, • define additional useful commands in linux OS., Manipulating files or directories, Using Linux isn't different from any other computer, operating system. You create, delete, and move files on, your hard drive in order to organize your information and, manage how your system works or looks. This section, shows you how to do these tasks quickly and easily., Although the graphical interface for Linux, the X Window, System, may offer drag and drop or multiple selections in, order to copy or delete files, many of the commands you'll, learn here form the base of these operations. It is worth, knowing how these programs work, even if you don't use, Linux in the console mode., Working with files, In this chapter we learn how to recognise, create, remove,, copy and move files using commands like file, touch, rm,, cp, mv and rename, etc…, All files are case sensitive, Files on Linux (or any Unix) are case sensitive. This means, that FILE1 is different from, file1, and /etc/hosts is different from /etc/Hosts (the latter, one does not exist on a typical Linux computer)., The file command, The file command attempts to classify each filesystem, object (i.e., file, directory or link) that is provided to it as, an argument (i.e., input). Thus, it can usually provide, immediate information as to whether some specified, object is, for example, a GIF89a image file, a directory, a, GNU tar archive, ASCII English text, a symbolic link, an, HTML document, an empty file, bzip2 compressed data,, an ELF 32-bit LSB executable, etc., File accomplishes this by probing each object with three, types of tests until one succeeds. The first is a filesystem, test, which uses the stat system call to obtain information, from the object's inode (which contains information about, a file). A system call is a request in a Unix-like operating, system for a service performed by the kernel (i.e., the, core of the operating system)., The second test checks to see if there is a magic number,, which is a number embedded at or near the beginning of, many types of files that indicates the file format(i.e., the, type of file)., , it is plain text (i.e., composed entirely of human-readable, characters), and, if so, what type of plain text, such as, HTML (hypertext markup language) or source code (i.e.,, the original version of a program as written by a human)., In this situation, file also attempts to determine the natural, language (e.g., English, Turkish or Japanese) that is used, in the file., A simplified version of file's syntax is, file [option(s)] object_name(s), File has several options, but it is most commonly used, without any of them. For example, information about a file, named file1 that is located in the in the current directory, (i.e., the directory in which the user is currently working), could be obtained by merely typing the following and, pressing the RETURN key:, file file1, Information about the types of all of the files in the, current directory can be obtained by using the star wildcard, to represent every object in that directory as, follows:, file *, Likewise, information about all of the files in another, directory can be obtained by using that directory as an, argument and following it immediately by a forward slash, and the star wildcard. For example, the following, classifies all of the objects in the /boot directory:, file /boot/*, The square brackets wildcard can be used together with, the star wildcard to show the file types for only those, objects whose names begin with specified letters or with, a specified range of letters. For example, the following, would show only those objects in the current directory, whose names begin with letters a through g:, file [a-g]*, The -k option tells file to not stop at the first successful, test, but to keep going; this can result in the reporting of, additional information about some filesystem objects. The, -b (i.e., brief) option tells file to not prepend filenames to, output lines, which can be useful when compiling statistics, about file types. The -v option returns information about, the version of file that is installed., , In the event that the first two tests fail to determine the, type of a file, language tests are employed to determine if, 80, , Copyright @ NIMI Not to be Republished
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Creating files and directories command, mkdir command, The mkdir command is is used to create new, directories., A directory, referred to as a folder in some operating, systems, appears to the user as a container for other, directories and files. However, Unix-like operating, systemstreat directories as merely a special type of file, that contains a list of file names and their corresponding, inode numbers. Each inode number refers to an inode,, which is located in inode tables (which are kept at, strategic locations around the filesystem) and which, contains all information about a file (e.g., size,, permissions and date of creation) except its name and, the actual data that the file contains., mkdir has the following example, $ mkdir example, , mkdir -m 777 dir_4, The first digit represents the owner, the second represents, the group and the third represents other users. The number, 7 represents all three types of permission (i.e., read, write, and execute), 6 stands for read and write only, 5 stands, for read and execute, 4 is read only, 3 is write and execute,, 2 is write only, 1 is execute only and 0 is no permissions., Thus, for example, to create a new directory named dir_5, for which the owner has read and write permissions, the, group has read permission and other users have no, permissions, the following would be used:, mkdir -m 640 dir_5, , $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, directory_name is the name of any directory that the user, is asking mkdir to create. Any number of directories can, be created simultaneously., Thus, for example, the following command would create, three directories within the current directory (i.e., the, directory in which the user is currently working) with the, names dir_1, dir_2 and dir_3:, mkdir dir_1 dir_2 dir_3, If a directory name provided as an argument (i.e., input) to, mkdir is the same as that of an existing directory or file in, the same directory in which the user is asking mkdir to, create the new directory, mkdir will return a warning, message such as mkdir: cannot create directory `dir_1':, File exists and will not create a file with that name., However, it will then continue to create directories for any, other names provided as arguments., It is necessary for a user to have write permission (i.e.,, permission from the system to create or change a file or, directory) in the parent directory (i.e., the directory in which, the new directory is to be created) in order to be able to, create a new directory., Directories created by mkdir automatically include two, hidden directories, one representing the directory just, created (and represented by a single dot) and the other, representing its parent directory (and represented by two, consecutive dots). This can be seen by using the ls (i.e.,, list) command with its -a option, which tells ls to show all, directories and files, (including hidden ones) in any directory, provided to it as an argument, or in the current directory if, there are no arguments, i.e.,, ls -a, , a program) permissions enabled for the owner (i.e., the, creator of the directory by default) and group and the read, and execute permissions enabled for other users. Thus,, for example, to create a directory named dir_4 for which, all three types of permissions were enabled for all users,, the sequence 777 would be employed after -m, for example:, , The -p (i.e., parents) option creates the specified, intermediate directories for a new directory if they do not, already exist. For example, it can be used to create the, following directory structure:, mkdir -p food/fruit/citrus/oranges, It is very easy to confirm that this series of directories has, been created by using the du (i.e., disk usage) command, with the name of the first directory as an argument. In the, case of the above example this would be, du food, Other options include -v (i.e., verbose), which returns a, message for each created directory, --help, which returns, brief information about mkdir, and --version, which returns, the version number of the currently installed mkdir program, touch command, The touch command updates the access and modification, times of each FILE to the current system time., If you specify a FILE that does not already exist, touch, creates an empty file with that name., If the FILE argument is a dash ("-") is handled specially, and causes touch to change the times of the file associated, with standard output., $ touch file1 file2 file3, $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file2, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, A feature of touch is that, in contrast to some commands, such as cp (which is used to copy files and directories), and mv (which is used to move or rename files and, , mkdir's -m option is used to control the permissions of, new directories. New directories are by default created, with the read, write and execute (i.e., run as a program if, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 81
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directories), it does not automatically overwrite (i.e., erase, the contents of) existing files with the same name. Rather,, it merely changes the last access times for such files to, the current time., Several of touch's options are specifically designed to allow, the user to change the timestamps for files. For example,, the -a option changes only the access time, while the -m, option changes only the modification time. The use of both, of these options together changes both the access and, modification times to the current time, for example:, touch -am file3, The -r (i.e., reference) option followed directly by a space, and then by a file name tells touch to use that file's time, stamps instead of current time. For example, the following, would tell it to use the times of file4 for file5:, touch -r file4 file5, The -B option modifies the timestamps by going back the, specified number of seconds, and the -F option modifies, the time by going forward the specified number of seconds., For example, the following command would make file7 30, seconds older than file6., touch -r file6 -B 30 file7, The -d and -t options allow the user to add a specific last, access time. The former is followed by a string (i.e.,, sequence of characters) in the date, month, year,, minute:second format, and the latter uses a, [[CC]YY]MMDDhhmm[.ss] format. For example, to change, the last access time of file8 to 10:22 a.m. May 1, 2005, 1, May 2005 10:22 would be enclosed in single quotes and, used as follows, i.e.,:, touch -d '1 May 2005 10:22' file8, Partial date-time strings can be used. For example, only, the date need be provided, as shown for file9 below (in, which case the time is automatically set to 0:00):, touch -d '14 May' file9, Just providing the time, as shown below, automatically, changes the date to the current date:, touch -d '14:24' file9, The most commonly used way to view the last modification, date for files is to use the ls command with its -l option., For example, in the case of a file named file10 this would, be, ls -l file10, The complete timestamps for any file or directory can be, viewed by using the stat command. For example, the, following would show the timestamps for a file named file11:, stat file11, The --help option displays a basic list of options, and the, --version option returns the version of the currently installed, touch program., , 82, , Copy, move and remove commands, Copy command, The cp command is used to copy files and directories., The copies become independent of the originals (i.e., a, subsequent change in one will not affect the other)., cp's basic syntax is, $cp source destination, As a safety precaution, by default cp only copies files and, not directories. If a file with the same name as that assigned, to the copy of a file (or a directory with the same name as, that assigned to the copy of a directory) already exists, it, will be overwritten (i.e., its contents will be lost). However,, the owner, group and permissions for the copy become, the same as those of the file with the same name that it, replaced. The last access time of the source file and the, last modification time of the new file are set to the time, the copying was performed., When a copy is made of a file or directory, the copy must, have a different name than the original if it is to be placed, in the same directory as the original. However, the copy, can have the same name if it is made in a different directory., Thus, for example, a file in the current directory (i.e., the, directory in which the user is currently working) named, file1 could be copied with the same name into another, directory, such as into /home/john/, as follows:, cp file1 /home/john/file1, Any number of files can be simultaneously copied into, another directory by listing their names followed by the, name of the directory. cp is an intelligent command and, knows to do this when only the final argument (i.e., piece, of input data) is a directory. The files copied into the, directory will all have the same names as the originals., Thus, for example, the following would copy the files named, file2, file3 and file4 into a directory named dir1:, cp file2 file3 file4 dir1, The -r (i.e., recursive) option, which can also be written, with an upper case R, allows directories including all of, their contents to be copied. (Directories are not copied by, default in order to make it more difficult for users to, accidentally overwrite existing directories which have the, same name as that assigned to the copy being made and, which might contain critical directory structures or, important data.) Thus, for example, the following command, would make a copy of an existing directory called dir2,, inclusive of all it contents (i.e., files, subdirectories, their, subdirectories, etc.), called dir3:, cp -r dir2 dir3, The -i (i.e., interactive) option prompts the user in the event, that any name assigned to a copy is already in use by, another file and that file would thus be overwritten. Entering, the letter y (either lower case or upper case) in response, to the prompt causes the command to continue; any other, answer prevents the command from overwriting the file., Thus, for example, if it is desired to make a copy of a, directory called dir4 and call it dir5 and if a directory named, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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dir4 already exists, the following would prompt the user, prior to replacing any files with identical names in the latter, directory:, cp -ri dir4 dir5, The -a option preserves as much of the structure and, attributes of the original directory and its contents as, possible in the new directory and is thus useful for creating, archives. It is similar to the -r option in that it copies, directories recursively; however, it also never follows, symbolic links. It is equivalent to the -rdp combination of, options., All the files in a directory can be copied to another directory, by using the star wildcard. The star character represents, any single character or any combination of characters., Thus, for example, the following would copy all of the files, in a directory named dir6 into another existing directory, called dir7:, cp dir6/* dir7, cp can also be used with the star wildcard or other pattern, matching characters to selectively copy files and, directories. For example, to copy all of the files in the, current directory that have the filename extension .html, into another existing directory called dir8, the following, would be used:, cp *.html dir8, In this case, the star wildcard represents anything whose, name ends with the .html extension., Among the other options for cp are -b, which makes backup, copies of each destination file, -f (i.e., force), which removes, destination files that cannot be opened and tries again, s, which makes symbolic links instead of copying, -u (i.e.,, update), which copies only if the source file is newer than, the destination file or if the destination file is missing, -v, (i.e., verbose), which makes brief comments about what, is going on, and -x, which tells cp to stay on the same, filesystem., Move command, The mv command is used to rename and move files and, directories. Its general syntax is:, $ mv source destination, The arguments are names of files and directories. If two, file names are provided as arguments, mv renames the, first as the second. If a list of arguments is provided and, the final argument in the sequence is the name of an, existing directory, mv moves all of the other items into, that directory. If the final argument is not an existing, directory and more than two arguments are provided, an, error message is returned., If the destination file is located in the same directory as, the source file, then the source file can only be renamed., If both are in different directories, then the source file is, moved to the directory named in the destination argument,, in which it can keep its original name or be assigned a, new name. If the target is a directory, then the source file, , or directory is moved into that directory and retains its, original name., Thus, for example, the following would rename a file called, file1 to file2, while keeping it in the current directory (i.e.,, the directory in which the user is currently working):, mv file1 file2, The following would move a file named file3, without, changing its name, from the current directory to an existing, subdirectory of the current directory named dir1:, mv file3 dir1/file3, mv can be used to move any number of files and directories, simultaneously. For example, the following command, moves all files and directories, including all the contents, of those directories, from the current directory to the, directory /home/alice/new/:, mv * /home/alice/new/, The asterisk is a wildcard character that represents any, string (i.e., sequence of characters). Thus, in the above, example it represents the name of every file and directory, in the current directory., mv makes it as easy to move a file or directory up the, hierarchy of directories (i.e., closer to the root directory), as down it. For example, the following would move a file, named file4, which is currently located in the subsubdirectory dir/dir/ of the user's home directory, to the, top level in the user's home directory:, mv dir/dir/file4 ~, The root directory is the directory that contains all other, directories on a Unix-like operating system and which is, at the top of the hierarchy of directories. A user's home, directory is the directory in which a user finds itself by, default after logging into the system and which can be, represented by the tilde (wavy horizontal linecharacter)., By default, mv does not provide any confirmation on the, display screen if its action is completed without problems., This is consistent with the rule of silence tenet of the Unix, philosophy., Thus it is wise for users new to Unix-like operating, systems to always use the -i option, which makes mv, interactive in the situation in which files and/or directories, with the same name already exist in the destination, directory. For example, the above command would be made, interactive as follows:, mv -i * /home/alice/new/, Among mv's few other options are -b, which tells it to make, a backup copy of each file that would otherwise be, overwritten or removed, and -v, which tells it to beverbose, and display the name of each file before moving it. Detailed, information (including all options) about mv can be obtained, by using its --help option, and information about the current, version can be obtained by using its --version option., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 83
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Remove or Delete, , begins with a dash or hyphen. For example, the following, removes a directory named -dir1:, , $ rmdir, 'rmdir' command removes any empty directories, but, cannot delete a directory if a file is present in it. To use, 'rmdir' command, you must first remove all the files present, the directory you wish to remove (and possibly directories, if any)., Remove files and directories, The rm (i.e., remove) command is used to delete files and, directories on Linux and other Unix-like operating systems., The general syntax for rm is:, rm [options] [-r directories] filenames, The items in square brackets are optional. When used, just with the names of one or more files, rm deletes all, those files without requiring confirmation by the user. Thus,, in the following example, rm would immediately delete the, files named file1, file2 and file3, assuming that all three, are located in the current directory (i.e., the, directory in which the user is currently working):, rm file1 file2 file3, Error messages are returned if a file does not exist or if, the user does not have the appropriate permission to delete, it. Write-protected files prompt the user for a confirmation, (with a y for yes and an n for no) before removal. Files, located in write-protected directories can never be removed,, even if those files are not write-protected., The -f (i.e., force) option tells rm to remove all specified, files, whether write-protected or not, without prompting the, user. It does not display an error message or return error, status if a specified file does not exist. However, if an, attempt is made to remove files in a write-protected, directory, this option will not suppress an error message., The -i (i.e., interactive) option tells rm to prompt the user, for confirmation before removing each file and directory. If, both the -f and -i options are specified, the last one specified, takes affect., As a safety measure, rm does not delete directories by, default. In order to delete directories, it is necessary to, use the -r option, which is the same as the -R option. This, option recursively removes directories and their contents, in the argument list; that is, the specified directories will, first be emptied of any subdirectories (including their, subdirectories and files, etc.) and files and then removed., The user is normally prompted for removal of any writeprotected files in the directories unless the -f option is, used., If a file encountered by rm is a symbolic link, the link is, removed, but the file or directory to which that link refers, will not be affected. A user does not need write permission, to delete a symbolic link, as long as the user has write, permission for the directory in which that link resides., The rm command supports the -- (two consecutive dashes), parameter as a delimiter that indicates the end of the, options. This is useful when the name of a file or directory, 84, , rm -r -- -dir1, Other options include -v (i.e., verbose), which provides, additional information about what is happening, --help,, which provides basic documentation about rm, and -version, which tells the version of rm that is currently in, use. Some differences exist among the various versions, of rm, so it is always wise to read the documentation for, the particular system., The rmdir command differs from rm in that it is only used, to remove empty directories, The rmdir command, The rmdir command is used to remove empty directories, in Linux, The syntax for rmdir is, rmdir [option] directory_names, When used without any options, rm will delete any empty, directories whose names are supplied as arguments (i.e.,, inputs) regardless of whether such directories have write, permission or not. Thus, for example, the following, command would remove two empty directories named dir1, and dir2 that are located in the current directory (i.e., the, directory in which the user is currently working):, rmdir dir1 dir2, The ability to remove only empty directories is a built-in, safeguard that helps prevent the accidental loss of data., This is important because once deleted, it is extremely, difficult or impossible to recover deleted data on Unix-like, operating systems1., The -p (i.e., parents) option tells rmdir to remove the parent, directories of the specified directory if each successive, parent directory will, in turn, become empty and if each, parent directory has write permission. Thus, for example,, the following would remove dir5, dir4 and dir3 if dir5 were, empty, dir4 only contained dir5 and dir3 only contained, dir4 (which, in turn, contained dir5):, rmdir -p dir3/dir4/dir5, This provides a symmetry with the -p option of the mkdir, command, which is used to create directories. Thus, the, above set of nested directories could be easily created, with the following:, mkdir -p dir3/dir4/dir5, In contrast to the rm command, which is used to delete, both files and directories, there is no -r option for rmdir. at, least on the GNU version that is standard on Linux. That, option allows rm to recursively delete a directory by first, deleting all of its contents, beginning with those in the, lowest levels of subdirectories. Thus, if a user wants to, remove an entire directory structure, it is usually most, efficient to use rm with its -r option rather than trying to, first remove the contents of each directory, its, subdirectories, etc., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Three options that rmdir shares with rm are -v (i.e., verbose),, which provides additional information about what is, happening, --help, which provides basicdocumentation, about rmdir, and --version, which tells the version of rmdir, that is currently in use. Some differences exist among the, various versions of rmdir, so it is always wise to read the, documentation for the particular system., Listing and combining files with the cat command, The cat (concatenate file) command is used to send the, contents of files to your screen. This, command may also be used to send files' contents into, other files. Hour 6 covers terms such as standard input,, standard output, and redirection, and this section shows, you some basic uses for this command., Although cat may be useful for reading short files, it is, usually used to either combine, create, overwrite, or, append files. To use cat to look at a short file, you can, enter, $ cat test.txt, This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., The cat command also has a number of options. If you'd, like to see your file with line, numbers, perhaps to note a specific phrase, you can use, the -n option:, , $ cat test.txt test2.txt, The output will be exactly the same as if had used a, wildcard. But looking at several files is only one way to, use cat. You can also use the cat command with the, redirection operator > to combine files. For example, if, you would like to combine test.txt and test2.txt into a, third file called test3.txt, you can use, $ cat test* > test3.txt, check the result with, # ls -l test*, In this case, user first decide whether you want the contents, of test.txt to go into test2.txt, or the contents of test2.txt, to go into test.txt . Then, using cat with the >> redirection, operator, you might type, $ cat test.txt >> test2.txt, This appends the contents of test.txt to the end of the, test2.txt . To check the results, use cat again:, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., Note that if you had entered the command., , $ cat -n test.txt, , • This text file was created by the cat command., • Cat could be the world's simplest text editor., • If you read this book, you'll learn how to use cat., • This is the last line of text in this file., and also use cat to look at several files at once, because, cat accepts wildcards, for example:, , $ cat -n test.txt >> test2.txt, The test2.txt file would look like, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., , $ cat -n test*, , • This text file was created by the cat command., , • This text file was created by the cat command., , • Cat could be the world's simplest text editor., , • Cat could be the world's simplest text editor., , • If you read this book, you'll learn how to use cat., , • If you read this book, you'll learn how to use cat., , • This is the last line of text in this file., , • This is the last line of text in this file., • This file was also created by cat., , Finally, here's a trick you can use if you want to create a, short text file without running a word processor or text, editor. Because the cat command can read the standard, input (more about this in Hour 6), you can make the cat, command create a file and fill it with your keystrokes., , • This is the last line of test2.txt., , Here's how:, , • This is the first line of test2.txt., , As you can see, cat has also included a second file in its, output, and has numbered each line of the output, not, each file. Note that also see both files with, , $ cat > myfile.txt, Now, enter some text:, $ cat > myfile.txt, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 85
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This is the cat word processor., This is the end of the file., Then, when you're done typing, press Ctrl+D to close the, file. To see if this works, try, $ ls -l myfile.txt, -rw-rw-r-- 1 bball bball 61 Nov 12 18:26 myfile.txt, $ cat myfile.txt, This is the cat word processor., This is the end of the file., user should also know that the cat command will print out, the contents of any file, and not, just text files. Although cat may be useful to look at one or, several short files,, Other file commands, The clear Command, The clear command is used to remove all previous, commands and output from consoles and terminal, windows in Unix-like operating systems., A console is an all-text mode user interface that, occupies the entire screen of the display device and which, does not sit on top of a graphical user interface (GUI). A, terminal window is a text-only window in a GUI that, emulates a console and which can be opened by clicking, the appropriate icon (i.e., small image) or menu item., , As another example, the following displays the man page, about the man pages:, man man, man automatically sends its output through a pager,, usually the program less. A pager is a program that causes, the output of any program to be displayed one screenful, at a time, rather than having a large amount of text scroll, down the screen at high (and generally unreadable) speed., less writes a colon at the bottom of the screen to indicate, the end of the on-screen page. The user can move to the, next page by pushing the space bar and can return to the, previous page by pressing the b key. Pressing the q exits, the man pages and returns the user to the shell program., Each man page is a self-contained article that is divided, into a number of sections, the headers for which are labeled, with upper case letters. The sections for commands are, typically something like NAME, SYNOPSIS,, DESCRIPTION, OPTIONS, AUTHOR, BUGS,, COPYRIGHT, HISTORY and SEE ALSO, although there, may be some differences according to the particular, command. Some of these might be broken down into, subsections, particularly OPTIONS in the case of a, command that has numerous options., Also, the man pages as a whole are organized into, sections, each containing pages about a specific category, of topics as shown below. The section to which an article, belongs is indicted in parenthesis in the top line, before, the NAME header., , Clear is one of the very few commands in Unix-like, operating systems that accepts neither options nor, arguments (i.e., input files). That is, it is only used as, follows:, , 1. executable programs or shell commands, , Clear, , 4. special files (i.e., devices in the /dev directory), , After the clear command has been issued, all that, remains on the display screen is the command prompt in, the upper left hand corner. A command prompt, also, referred to as a prompt, is a short text message at the, start of a line that informs the user that the system is, ready for the next command, data element or other, input., , 5. file formats, , The descriptions are rather terse, and they can seem, somewhat cryptic to new users. However, users typically, find them to be increasingly useful as they become more, familiar with them and gain experience in the use of Unixlike operating systems., , Some topic names will have multiple articles, depending, on context. For instance, there are two articles for mount,, one corresponding to its use as a command in system, management (i.e., to logically attach partition or other, devices to the main filesystem) and the other for use in, the C programming language. Generally, the most, commonly used topic is displayed by default, and there, are references to any other topics with the same name in, the SEE ALSO section at the bottom of the final on-screen, page., , The man command itself is extremely easy to use. Its, basic syntax is, man [option(s)] keyword(s), man is most commonly used without any options and, with only one keyword. The keyword is the exact name of, the command or other item for which information is desired., For example, the following provides information about the, ls command (which is used to list the contents of any, specified directory):, man ls, 86, , 2. system calls, 3. library routines, , 6. games, 7. macro packages, 8. system administration commands, 9. kernel routines, , The syntax to specify an article from a particular section, is:, man section_number keyword, , Thus, for example, the following would display the article, about mount from Section 2 instead of from the default, Section 8:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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man 2 mount, The -w and -W options tell man to not actually display the, man pages, but to provide the location(s) of the file(s) that, would be formatted or displayed. If noarguments (i.e., input, files) are provided, a list of directories that is searched by, man for man pages is returned., The -f option produces the same output as the whatis, command. whatis provides very brief descriptions of, commands from a database that is automatically created, from the first line of the NAME section of each relevant, man page., The Whoami and who command, The whoami command writes the user name (i.e., login, name) of the owner of the current login session to standard, output. Standard output is, by default, the display screen,, unless redirected to a file, printer, etc., , as additional information about each of those users, (including login times and terminal numbers). It also, differs in that, in the event of a change in ownership of a, login session through the use of the su command, it, reports the original owner of the session, whereas whoami, provides the user name of the effective (i.e., current) owner, of the session., stat command, File Stat - Display Information About File, For example, to find out more information about, 101hacks.txt file, execute the stat command as shown, below., $ stat 101hacks.txt, File: `/home/sathiyamoorthy/101hacks.txt', Size: 854, , Blocks: 8 IO Block: 4096 regular file, , whoami is particularly useful when using shells such as, ash and sh that do not show the name of the current user, in the command prompt (a short text message at the start, of the command line on an all-text display). It is also useful, for confirming the current owner of a session after using, the su (i.e., substitute user) command, which changes, the owner of the session without the original owner having, to first log out., , Device: 801h/2049d, , A shell is a program that provides the traditional, text-only, user interface forUnix-like operating systems. Its primary, function is to read commands that are typed into a console, (i.e., an all-text display mode) or terminal window(an alltext window in a GUI) and then execute (i.e., run) them., , Details of Linux stat command output, , The formal syntax for whoami is:, , • Blocks: 8 - Total number of blocks used by this file., , whoami [option], When used without any options or redirection, as it usually, is, i.e.,, Whoami, , Inode: 1058122, , Links: 1, , Access: (0600/-rw-------) Uid: ( 1000/ sathiya), Gid: ( 1000/ sathiya), Access: 2009-06-28 19:29:57.000000000 +0530, Modify: 2009-06-28 19:29:57.000000000 +0530, Change: 2009-06-28 19:29:57.000000000 +0530, , • File: `/home/sathiyamoorthy/101hacks.txt' - Absolute, path name of the file., , • Size: 854 - File size in bytes., • IO Block: 4096 - IO block size for this file., • Regular file - Indicates the file type. This indicates, , that this is a regular file. Following are available file, types., , and followed by pressing the ENTER key, whoami displays, on the monitor screen the user name of the owner of the, current session., , − regular file. ( ex: all normal files )., , There are only two options for whoami: --help and --version., The former outputs the very brief description that is, contained in the man (i.e., built-in system manual) pages,, and the latter outputs the number of the version currently, installed on the system., , − socket. ( ex: sockets )., , whoami produces the same result as the id command, (which by default provides more detailed information about, the current user than does whoami) when id is used with, its -u and -n options, i.e.,, , − character special file. ( ex: terminal device file)., , id -un, The -u option tells id to provide only the identification for, the current owner of the session, and the -n option tells it, to present that identification as the user name instead of, as a number., The who command differs from whoami in that it provides, a list of all users currently logged into the system as well, , − directory. ( ex: directories )., − symbolic link. ( ex: symbolic links. ), − block special file ( ex: hard disk )., • Device: 801h/2049d - Device number in hex and device, number in decimal, , • Inode: 1058122 - Inode number is a unique number for, , each file which is used for the internal maintenance by, the file system., , • Links: 1 - Number of links to the file, • Access: (0600/-rw---): Access specifier displayed in, , both octal and character format. Let us see explanation, about both the format., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 87
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• Uid: ( 1000/ sathiya) - File owner's user id and user, , between. Thus, the following command would produce the, same result:, , • Gid: ( 1000/ sathiya) - File owner's group id and group, , head -n 15 aardvark armadillo, , name are displayed., name are displayed., , • Access: 2009-06-28 19:29:57.000000000 +0530 - Last, access time of the file., , • Modify: 2009-06-28 19:29:57.000000000 +0530 - Last, modification time of the file., , • Change: 2009-06-28 19:29:57.000000000 +0530 - Last, change time of the inode data of that file., , Dir Stat - Display Information About Directory You can, use the same command to display the information about, a directory as shown below., $ stat /home/ramesh, , In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell head how many lines to, return. Thus, the following would produce the same, result as the above commands:, head -15 aardvark armadillo, head can also return any desired number of bytes (i.e., a, sequence of eight bitsand usually long enough to represent, a single character) from the start of each file rather than a, desired number of lines. This is accomplished using the coption followed by the number of bytes desired. For, example, the following would display the first five bytes of, each of the two files provided:, , File: `/home/ramesh', , head -c 5 aardvark anteater, , Size: 4096 Blocks: 8 IO Block: 4096 directory, , When head counts by bytes, it also includes the newline, character, which is anon-printing (i.e, invisible) character, that is designated by a backslash and the letter n (i.e.,, \n). Thus, for example, if there are three new, blank lines, at the start of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or on, paper)., , Device: 803h/2051d Inode: 5521409 Links: 7, Access: (0755/drwxr-xr-x) Uid: ( 401/ramesh), Gid: (401/ramesh), Access: 2009-01-01 12:17:42.000000000 -0800, Modify: 2009-01-01 12:07:33.000000000 -0800, Change: 2009-01-09 12:07:33.000000000 -0800, The head command reads the first few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the display screen)., , The number of bytes or lines can be followed by a, multiplier suffix. That is, adding the letter b directly after, the number of bytes multiplies it by 512, kmultiplies it by, 1024 and m multiplies it by 1048576. Thus, the following, command would display the first five kilobytes of the file, aardvark:, , head's basic syntax is:, , head -c5k aardvark, , head command, , head [options] [file(s)], The square brackets indicate that the enclosed items are, optional. By default, head returns the first ten lines of each, file name that is provided to it., For example, the following will display the first ten lines of, the file namedaardvark in the current directory (i.e., the, directory in which the user is currently working):, head aardvark, If more than one input file is provided, head will return the, first ten lines from each file, precede each set of lines by, the name of the file and separate each set of lines by one, vertical space. The following is an example of using head, with two input files:, head aardvark armadillo, If it is desired to obtain some number of lines other than, the default ten, the -noption can be used followed by an, integer indicating the number of lines desired. For example,, the above example could be modified to display the first, 15 lines from each file:, head -n15 aardvark armadillo, , The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter ccannot be omitted as, can the letter n, because in such case head would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like head: aardvark: invalid number of bytes:, head -c aardvark, If head is used without any options or arguments (i.e., file, names), it will await input from the keyboard and will, successively repeat (i.e., each line will appear twice) on, the monitor screen each of the first ten lines typed on the, keyboard. If it were desired to repeat some number of, lines other than the default ten, then the -n option would, be used followed by the integer representing that, number of lines (although, again, it is not necessary to, include the letter n), e.g.,, head -n3, As is the case with other command line (i.e., all-text mode), programs in Linuxand other Unix-like operating systems,, the output from head can redirectedfrom the display monitor, to a file or printer using the output redirection operator, (which is represented by a rightward-pointing angular, , -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, 88, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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bracket). For example, the following would copy the first, 12 lines of the file Yuriko to the fileDecember:, head -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two consecutive rightward pointing angle brackets) could, be used to add the output from head to the end of a file, with that name if it already existed (or otherwise create a, new file with that name), i.e.,, head -n 12 Yuriko >> December, The output from other commands can be sent via a pipe, (represented by thevertical bar character) to head to use, as its input. For example, the following sends the output, from the ls command (which by default lists the names of, the files and directories in the current directory) to head,, which, in turn, displays the first ten lines of the output that, it receives from ls:, ls | head, This output could easily be redirected, for example to the, end of a file namedfile1 as follows:, ls | head >> file1, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reverse alphabetic order, prior to appending file1:, ls | head | sort -r >> file1, The -q (i.e., quiet) option causes head to not show the file, name before each set of lines in its output and to eliminate, the vertical space between each set of lines when there, are multiple input sources. Its opposite, the -v (i.e., verbose), option, causes head to provide the file name even if there, is just a single input file., The tail command is similar to the head command except, that it reads the final lines in files rather than the first, lines., As is the case with other commands on Unix-like operating, systems, additional information can be obtained about head, and tail by using the man and infocommands to reference, the built-in documentation, for example, man head, or, info tail, tail command, The tail command reads the final few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the monitor screen)., The basic syntax for tail is:, tail [options] [filenames], $ tail -n 4 /etc/passwd, , The square brackets indicate that the enclosed items are, optional. By default, tail returns the final ten lines of each, file name that is provided to it., For example, the following command will print (traditional, Unix terminology for write) the last ten lines of the file, named aardvark in the current directory (i.e., the director, in which the user is currently working) to the display, screen:, tail aardvark, If more than one input file is provided, tail will print the last, ten lines from each file to the monitor screen. Each set of, lines will be preceded by the name of the file and separated, by one vertical space from other sets of lines. The following, is an example of using tail with multiple input files:, tail file1 file2 file3, If it is desired to print some number of lines other than the, default ten, the -n option can be used followed by an integer, indicating the number of lines desired. For example, to, print the final 15 lines from each file in the above example,, the command would be modified as follows:, tail -n15 file1 file2 file3, -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, between. Thus, the following command would produce the, same result:, tail -n 15 file1 file2 file3, In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell tail how many lines to print. Thus, the, following would produce the same result as the above, commands:, tail -15 file1 file2 file3, tail can also print any desired number of bytes (i.e., a, sequence of eight bits and usually long enough to represent, a single character) from the end of each file rather than a, desired number of lines. This is accomplished using the c option followed by the number of bytes desired. For, example, to view the final five bytes of each of the two files, aardvark and anteater, the following command would be, used:, tail -c 5 file1 file2, When tail counts by bytes, it also includes the newline, character, which is a non-printing (i.e, invisible) character, that is designated by a backward slash and the letter n, (i.e., \n). Thus, for example, if there are three new, blank, lines at the end of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or paper)., The number of bytes or lines can be followed by a multiplier, suffix. That is, adding the letter b directly after the number, of bytes multiplies it by 512, k multiplies it by 1024 and m, multiplies it by 1048576. Thus, the following command, would print the last five kilobytes of the file aardvark:, tail -c5k file1, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 89
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The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter c cannot be omitted as, can the letter n, because in such case tail would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like tail: aardvark: invalid number of bytes:, tail -c file1, If tail is used without any options or arguments (i.e., inputs),, it will await input from the keyboard and will successively, repeat (i.e., each line will appear twice) on the monitor, screen each of the final ten lines typed on the keyboard. If, it were desired to repeat some number of lines other than, the default ten, then the -n option would be used followed, by the integer representing that number of lines (although,, again, it is not necessary to include the letter n), e.g.,, tail -n3, As is the case with other command line (i.e., all-text mode), programs in Unix-like operating systems, the output of, tail can be redirected from the monitor to a file or printer, using the redirection operator (which is represented by a, rightward pointing angular bracket). For example, the, following would write the final 12 lines of the file Yuriko to, the file December:, tail -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two rightward pointing angular brackets) could be used to, add the output from tail to the end of a file with that name, if it already existed (or otherwise create a new file with, that name), i.e.,, tail -n 12 Yuriko >> December, The output from other commands can be piped (i.e., sent), to tail to use as its input. For example, the following sends, the output from the ls command (which by default lists the, names of the files and directories in the current directory), to tail, which, in turn, prints the final ten lines of the output, that it receives from ls to the monitor screen:, ls | tail, , Tail can be instructed to begin printing from some number, of lines or bytes from the start of a file by preceding the, number with a plus sign instead of a minus sign. For, example, the following would print each of the designated, files to the display monitor beginning with the seventh line, and until the end:, tail +7 file1 file2 file3, The c option could be used to tell tail to print each of the, designated files beginning with the seventh byte instead, of the seventh line:, tail +7c file1 file2 file3, A particularly common application for tail is examining the, most recent entries in log files. This is because the newest, entries are appended to the ends of such files, which tail, excels in showing. As log files can be a rather long, this, can eliminate a lot of scrolling that would be necessary if, some other command were used to read them. For, example, the most recent entries to the log /var/log/, messages can easily be viewed by using the, following:, tail /var/log/messages, wc command, The wc (i.e., word count) command by default counts the, number of lines, words and characters in text., wc defines a word as a set of contiguous letters, numbers, and/or symbols which are separated from other characters, by one or more spaces, tabs and/or newline characters, (which are generated when the RETURN key is pressed)., When counting the number of characters, all characters, are counted, not only letters, numbers and symbols, but, also spaces, tabs and newline characters. A line is only, counted if it ends with a newline character., wc's syntax is, , This output could easily be redirected, for example to a, file named last_filenames as follows:, ls | tail >> last_filenames, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reversealphabetic order, prior to writing to a file:, ls | tail | sort -r >> last_filenames, The -q (i.e., quiet) option causes tail to not print the file, name before each set of lines and to eliminate the vertical, space between each set of lines when there are multiple, input sources. The -v (i.e., verbose) option causes tail to, print the file name even if there is just a single input file., 90, , Tail could be viewed as a counterpart of the head command,, which always starts reading from the beginning of files, and which can continue until any specified distance from, the beginning. However, there are a few differences. Perhaps, the most useful of these is that tail is somewhat more, flexible in that, in addition to being able to start reading, any specified distance from the end of a file, it can also, start at any specified distance from the beginning of a file., , wc [options] [file_name(s)], The items in square brackets are optional. If no file names, are provided, wc reads from its standard input, which by, default is text entered at the keyboard., This can be seen by typing., wc, at the command line (i.e., in the all-text mode), pressing, the ENTER key to move to a new line and then typing, some text on one or more lines. The command isexecuted, (i.e., run) by pressing the ENTER key again and then, pressing the CONTROL and d keys simultaneously. This, causes wc to write in a new line (under the lines of text), its count of the numbers of lines, words and characters in, the text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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The following command counts the number of lines, words, and characters in a file named file1 that resides in the, current directory (i.e., the directory in which the user is, currently working) and likewise writes them, followed by, the name of the file, to standard output, which is by default, the display monitor:, , cat file6, grep command, grep is used to search text for patterns specified by the, user. It is one of the most useful and powerful commands, on Linux and other Unix-like operating systems., grep's basic syntax is:, , wc file1, wc can provide its output for multiple files by listing the, name of each separated by a space. For example,, wc file1 file2 file3, The numbers of lines, words and characters for each file, along with its name will be displayed on a separate line, and in the order that the files are listed as arguments(i.e.,, input files). In the case of multiple arguments such as, this, wc also provides an additional line that shows the, total number of lines, words and characters for all the files., Likewise, wc can provide a count for all of the text files, within a directory. This is accomplished by using the star, wildcard character, which represents everythingand is, designated by an asterisk ( * ). For example, the following, will display the number of lines, words and, characters for each file in the current directory (which is, represented by a dot) as well as totals for all files in the, directory:, wc . *, wc has only a few options, the most commonly used of, which restrict the information it provides. The -l option tells, wc to count only the number of lines, the -woption tells it, to count only the number of words, the -m option tells it to, count only the number of characters and the -c option, tells wc to count only the number ofbytes. Thus, for, example, the following displays just the number of words, in a file named file4:, wc -w file4, The following displays the number of characters in the, same file:, wc -m file4, As is generally the case with commands in Unix-like, operating systems, any combination of options can be, used together. For example, the following would count both, the numbers of lines and words in a file named file5:, wc -lw file5, Redirection can be used with wc to create more complex, commands. For example, the output from the above, command can be redirected using the standard output, redirection operator (which is designated by a rightward, pointing angle bracket) from the display screen to a file, named file6 with the following:, wc -lw file5 > file6, If file6 already exists, its contents will be overwritten; if it, does not exist, it will be created. The contents of file6 can, be easily confirmed with a text editor or with a command, such as cat, which is commonly used to read text files,, i.e.,, , grep [option(s)] pattern [file(s)], The items in square brackets are optional. When used, with no options and no arguments (i.e., input files), grep, searches standard input (which by default is text typed in, at the keyboard) for the specified pattern and returns each, line that contains a match to standard output (which by, default is the display screen)., A line of text is defined in this context not as what, appears as a line of text on the display screen but rather, as all text between two newline characters. Newline, characters are invisible characters that are represented in, Unix-like operating systems by a backslash followed by, the letter n and which are created when a user presses, the ENTER key when using a text editor (such as gedit)., Thus, a line of text returned by grep can be as short as a, single character or occupy many lines on the display, screen., grep can search any number of files simultaneously. Thus,, for example, the following would search the three files file1,, file2 and file3 for any line that contains thestring (i.e.,, sequence of characters) Lin:, grep Lin file1 file2 file3, Each result is displayed beginning on a separate line, and, it is preceded by the name of the file in which it was found, in the case of multiple files. The inclusion of the file names, in the output data can be suppressed by using the -h, option., grep is not limited to searching for just single strings. It, can also search for sequences of strings, including, phrases. This is accomplished by enclosing the sequence, of strings that forms the pattern in quotation marks (either, single or double). Thus, the above example could be, modified to search for the phrase Linux is:, grep 'Linux is' file1 file2 file3, Text searches with grep can be considerably broadened, by combining them with wildcards and/or performing, recursive searches. A wildcard is a character that can, represent some specific class of characters or sequence, of characters. The following is a modification of the above, example that uses the star wildcard (i.e., an asterisk),, which represents any character or sequence of characters,, to search all text files in the current directory (i.e., the, directory in which the user is currently working):, grep 'Linux is' *, , grep's search area can be broadened even further by using, its -r option to search recursively through an entire directory, tree (i.e., a directory and all levels of subdirectories within, it) rather than just the files within a specified directory. For, example, the following would search all files in the current, 91, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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directory and in all of its subdirectories (including their, subdirectories, etc.) for every line containing the full name, of the creator of Linux:, grep -r 'Linus Torvalds' *, One of the most commonly employed of grep's many, options is -i, which instructs it to ignore case, that is, to, ignore whether letters in the pattern and text searched are, lower case (i.e., small letters) or upper case (i.e., capital, letters). Thus, for instance, the previous example could, very easily be converted to a case-insensitive search as, follows:, grep -ir 'Linus Torvalds' *, This would produce the same results as, grep -ir 'linUS torvAlds' *, Another frequently used option is -c, which causes grep, to only report the number of times that the pattern has, been matched for each file and to not display the actual, lines. Thus, for instance, the following would show the, total number of times that the string inu appears in a file, named file4:, grep -c inu file4, Another useful option is -n, which causes grep to precede, each line of output with the number of the line in the text, file from which it was obtained. The -v option inverts the, match; that is, it matches only those lines that do not, contain the given pattern., The -w option tells grep to select only those lines that, contain an entire word or phrase that matches the, specified pattern. The -x option tells grep to select only, those lines that match exactly the specified pattern., The -l option tells grep to not return the lines containing, matches but to only return only the names of the files that, contain matches. The -L option is the opposite of the -l, option (and analogous to the -v option) in that it will cause, grep to return only the names of files that do not contain, the specified pattern., grep does not search the names of files for a specified, pattern, only the text contained within files. However,, sometimes it is useful to search the names of files, as, well as of directories and links, rather than the contents of, files. Fortunately, this can easily be accomplished by first, using the ls command to list the contents of a directory, and then using a pipe (which is represented by the vertical, bar character) to transfer its output to grep for searching., For example, the following would provide a list of all files,, directories and links in the current directory that contain, the string linu in their names:, ls | grep linu, The following example uses ls with its -l (i.e., long) option, (which is unrelated to grep's -l option) to find all filesystem, objects in the current directory whose permissions have, been set so that any user can read, write and execute, them:, ls -l | grep rwxrwxrwx, 92, , grep is very useful for obtain information from log and, configuration files. For example, it can be used to obtain, information about the USB (universal serial bus) devices, on a system by filtering the output from the dmesg, command (which provides the messages from the kernel, as a system is booting up) as follows:, dmesg | grep -i usb, Among grep's other options are --help, which provides a, very compact summary of some of its many capabilities,, and -V, or --version, which provides information about the, currently installed version., grep's search functionality can be even further refined, through the use of regular expressions. These are a pattern, matching system that uses strings constructed according, to pre-defined syntax rules to find desired patterns in text., Additional information about grep, including its use with, regular expressions, can be obtained from its built-in, manual page by using the man command, i.e.,, man grep, The name grep comes from a command in ed, which was, the original text editor on the UNIX operating system. The, command takes the form g/re/p, which means to search, globally for matches to the regular expression (i.e., re),, and print (which is UNIX terminology for write on the display, screen) lines that are found., ln command, ln command is used to create links. Links are a kind of, shortcuts to other files. The general form of command is:, $ ln TARGET LINK_NAME, There are two types of links, soft links and hard links. By, default, hard links are created. If you want to create soft, link, use -s option. In this example, both types of links are, created for the file usrlisting., $ ln usrlisting hard_link, $ ln -s usrlisting soft_link, $ ls -l, total 12, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 hard_link, lrwxrwxrwx 1 raghu raghu 10 2012-07-09 14:00 soft_link > usrlisting, -rw-r--r-- 1 raghu raghu 491 2012-07-06 16:02 usrcopy, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 usrlisting, Some additional useful commands, alias command, 'alias' is another name for a command. If no argument is, given, it shows current aliases. Aliases can be used for, short names of commands. For example, you might use, clear command frequently. You can create an alias for it:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ alias c="clear", Next time enter c on command line, your screen will be, clear. Current aliases can be checked with 'alias', command:, $ alias, alias alert='notify-send --urgency=low -i "$([ $? = 0 ] &&, echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/, ^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"', alias c='clear', alias egrep='egrep --color=auto', alias fgrep='fgrep --color=auto', alias grep='grep --color=auto', alias l='ls -CF', alias la='ls -A', alias ll='ls -alF', alias ls='ls --color=auto', w command, The w command shows who is logged in to the system, and what they are doing., A login, logging in or logging on is the entering of identifier, information into a system by a user in order to access, that system (e.g., a computer or a website). It generally, requires the user to enter two pieces of information, first a, user name and then a password., The basic syntax of w is:, w [options] [username1, username2, . . .], The square brackets indicated that the enclosed items, are optional. When used without any options, w sends to, standard output (which is by default the display screen) a, header line followed by a table that contains a line of data, for each user currently logged in., The header shows six items: the current time, how long, the system has been running (in minutes) since it was, booted up (i.e., started up), how many users are currently, logged on, and the system load averages, i.e., the average, number of processes active, during the last one, five and, 15 minutes. A process is an executing(i.e., running), instance of a program., The main part of w's output consists of a table showing, eight items of information for each user currently logged, into the system. The eight columns are labeled USER,, TTY, FROM, LOGIN@, IDLE, JCPU, PCPU and WHAT., USER is the login name of the user. TTY (which now, stands for terminal type but originally stood for teletype), is the name of the console or terminal (i.e., combination, of monitor and keyboard) that the user logged into, which, can also be found by using the tty command. Every time, a user logs in across the network, a new tty is assigned, to that user., , independent logical consoles that run in separate login, sessions, but which are accessed from the same physical, console (i.e., the same keyboard and screen). That is,, each virtual console can have a different, or the same,, user logged into it. On a Red Hat system, seven virtual, consoles are configured and active by default., FROM is the remote host (i.e., the name of some other, computer), if any, that the user logged into. LOGIN@ is, the time at which the user logged in. IDLE is the number, of hours and minutes since the user last typed anything, at the keyboard., JCPU is the number of minutes accumulated by all, processes attached to the tty. It does not include past, background processes (i.e., low priority processes that, operate only in gaps between higher priority foreground, processes), but it does include currently running, background processes., PCPU is the time consumed by the current process,, named in the WHAT column. WHAT lists the name of the, current process along with any options and arguments(i.e.,, input files) used with the command that launched it., Among the more useful of w's few options is -h, which, tells it to omit the header header line from its output. The, -s option tells it to use the short format, which omits the, login time, JCPU and PCPU columns. The -l option creates, a long listing, which is the same as the default. The -V, option displays the version number of the currently installed, w program., By default, w reports on all users. However, it can be made, to report on only a specified set of users by providing those, usernames in a comma-separated list., w provides information similar to that which would be, provided by a combination of the uptime, who and ps -a, commands. uptime produces a single line of output that, is the same as w's header line. who shows who is currently, logged into the system. ps -a lists all processes with a tty, except session leaders (i.e., processes that created, sessions)., w can be useful, but there are some faults with the, information it provides, and thus its output should only be, considered approximate. In particular, the notion of, thecurrent process is unclear and there are some problems, detecting background processes, even though they usually, account for much of the load on the system. Also, the, CPU time is only an estimate; for example, if a user leaves, a background process running after logging out, the time, is credited to the person currently on that terminal., last command, Display information about the users who logged in and out, of the system. The output of last can be very large, so the, following output has been filtered (through head) to display, top 10 lines only:, , The consoles can be real or virtual. A feature of Linux, systems is the use of virtual consoles, which act as, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 93
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$ last | head, root tty1 Mon Jul 9 10:06 still logged in, root tty1 Mon Jul 9 10:06 - 10:06 (00:00), raghu pts/1 :0.0 Mon Jul 9 10:05 - 10:06 (00:00), raghu pts/0 :0.0 Mon Jul 9 09:34 still logged in, raghu tty7 :0 Mon Jul 9 09:19 still logged in, , /dev/sda2 209715196 196519248 13195948 94%/, media/Data, fdisk command, The fdisk is the tool for getting partition information, adding, and removing partitions.The fdisk tool requires super user, privileges. To list all the partitions of all the hard drives, available:, $ fdisk -l, , reboot system boot 2.6.38-13-generi Mon Jul 9 09:09 10:12 (01:02), , Disk /dev/sda: 320.1 GB, 320072933376 bytes, , raghu tty7 :0 Sun Jul 8 23:36 - 00:30 (00:54), , 255 heads, 63 sectors/track, 38913 cylinders, , reboot system boot 2.6.38-13-generi Sun Jul 8 23:36 00:30 (00:54), , Units = cylinders of 16065 * 512 = 8225280 bytes, , raghu tty7 :0 Sun Jul 8 21:07 - down (01:06), reboot system boot 2.6.38-13-generi Sun Jul 8 21:07 22:14 (01:07), A similar command is lastb that shows last bad login, attempts. But this command must be run as root otherwise, would get an error of permission denied, $ lastb, raghu tty2 Mon Jul 9 10:16 - 10:16 (00:00), UNKNOWN tty2 Mon Jul 9 10:15 - 10:15 (00:00), ubuntu tty8 :1 Mon Jul 2 10:23 - 10:23 (00:00), btmp begins Mon Jul 2 10:23:54 2012, du command, du command determines disk usage of a file. If the, argument given to it is a directory, then it will list disk, usage of all the files and directories recursively under that, directory:, $ du /etc/passwd, 4 /etc/passwd, , Sector size (logical/physical): 512 bytes / 512 bytes, I/O size (minimum/optimal): 512 bytes / 512 bytes, Disk identifier: 0x396f396f, Device Boot Start End Blocks Id System, /dev/sda1 1 2611 20971520 7 HPFS/NTFS, /dev/sda2 2611 28720 209715200 7 HPFS/NTFS, /dev/sda3 * 28720 38914 81882113 5 Extended, /dev/sda5 28720 33942 41943040 7 HPFS/NTFS, /dev/sda6 33942 34464 4194304 7 HPFS/NTFS, /dev/sda7 34464 35739 10240000 83 Linux, /dev/sda8 35739 36376 5120000 83 Linux, /dev/sda9 36376 36886 4096000 82 Linux swap / Solaris, /dev/sda10 36887 38276 11164672 83 Linux, /dev/sda11 38277 38914 5117952 83 Linux, fdisk is an interactive tool to edit the partition table. It, takes a device (hard disk) as an argument, whose partition, table needs to be edited., $ fdisk /dev/sda, , $ du hello/, 4 hello/orb.db/logs, , WARNING: DOS-compatible mode is deprecated. It's, strongly recommended to switch off the mode (command, 'c') and change display units to sectors (command 'u')., , 20 hello/orb.db, , Command (m for help): m, , 52 hello/HelloApp, , 108 hello/, , Command, , action, , df command, , a, , toggle a bootable flag, , df reports file system usage. For example:, , b, , edit bsd disk label, , c, , toggle the dos compatibility flag, , Filesystem 1K-blocks Used Available Use% Mounted on, , d, , delete a partition, , /dev/sda7 10079084 7372872 2194212 78% /, , l, , list known partition types, , none 1522384 768 1521616 1% /dev, , m, , print this menu, , $ df, , none 1529012 252 1528760 1% /dev/shm, , n, , add a new partition, , none 1529012 108 1528904 1% /var/run, , o, , create a new empty DOS partition table, , none 1529012 4 1529008 1% /var/lock, , p, , print the partition table, , /dev/sda8 5039616 3758824 1024792 79% /home, , q, , quit without saving changes, , 94, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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s, , create a new empty Sun disklabel, , t, , change a partition's system id, , u, , change display/entry units, , v, , verify the partition table, , w, , write table to disk and exit, , x, , extra functionality (experts only), , Pressing 'm' at the fdisk prompt prints out above help that, lists all the commands available for fdisk. A new, partition can be created with n and an existing partition, can be deleted with d command. When you are done editing, the partitions, press w to write the changes to the disk,, and finally, q to quit from fdisk (q dies not save changes)., netstat command, 'netstat' is the command used to check the network, statistics of the system. It will list the current network, connections, routing table information, interface, statistics, masquerade connections and a lot more, information., $ netstat | head, Active Internet connections (w/o servers), Proto Recv-Q Send-Q Local Address Foreign Address State, Active UNIX domain sockets (w/o servers), Proto RefCnt Flags Type State I-Node Path, unix 13 [ ] DGRAM 8498 /dev/log, unix 2 [ ] DGRAM 6824 @/org/kernel/udev/udevd, unix 3 [ ] STREAM CONNECTED 56738 /var/run/dbus/, system_bus_socket, unix 3 [ ] STREAM CONNECTED 56113, , All of the files on a system have permissions that allow or, prevent others from viewing, modifying or executing. If the, file is of type Directory then it restricts different actions, than files and device nodes. The super user "root" has the, ability to access any file on the system. Each file has, access restrictions with permissions, user restrictions with, owner/group association. Permissions are referred to as, bits., If the owner read & execute bit are on, then the permissions, are:, There are three types of access restrictions:, Permission, , (view), , r or 4, , write, , (edit), , w or 2, , execute, , passwd command, Change your password with 'passwd' command., shutdown -h now, Finally shut down your system using this command., Understanding and using file permissions, In Linux and Unix, everything is a file. Directories are files,, files are files and devices are files. Devices are, usually referred to as a node; however, they are still files., , (execute), , x or 1, , There are also three types of user restrictions:, User, , ls output, , owner, , -rwx------, , group, , ----rwx---, , other, , -------rwx, , The restriction type scope is not inheritable:, the file owner will be unaffected by restrictions, set for his group or everybody else., Folder/Directory Permissions, Directories have directory permissions. The directory, permissions restrict different actions than with files or device, nodes., Permission, , Action, , chmod option, , Read, , (view contents,, i.e. ls command), , r or 4, , Write, , (create or remove, files from dir), , w or 2, , execute, , (cd into directory), , x or 1, , history command, This command shows the commands you have entered, on your terminal so far., , Chmod option, , read, , unix 3 [ ] STREAM CONNECTED 29138, unix 3 [ ] STREAM CONNECTED 29137, , Action, , 1. read restricts or allows viewing the directories contents,, i.e. ls command, 2. write restricts or allows creating new files or deleting, files in the directory. (Caution: write access for a, directory allows deleting of files in the directory even if, the user does not have write permissions for the file!), 3. execute restricts or allows changing into the directory,, i.e. cd command, Folders (directories) must have 'execute' permissions set, (x or 1), or folders (directories) will NOT FUNCTION as, folders (directories) and WILL DISAPPEAR from view in, the file browser (Nautilus)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 95
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Permissions in Action, , Here are a few examples of chmod usage with letters (try, these out on your system)., , $ ls -l /etc/hosts, -rw-r--r-- 1 root root 288 2005-11-13 19:24 /etc/hosts, Using the example above we have the file "/etc/hosts", which is owned by the user root and belongs to the root, group., The permissions from the above /etc/hosts ls output, -rw-r--r-owner = Read & Write (rw-), group = Read (r--), , First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, total 0, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, , other = Read (r--), , Add owner execute bit:, , Changing permissions, The command to use when modifying permissions is, chmod. There are two ways to modify permissions, with, numbers or with letters. Using letters is easier to, understand for most people. When modifying permissions, be careful not to create security problems. Some files are, configured to have very restrictive permissions to prevent, unauthorized access. For example, the /etc/shadow file, (file that stores all local user passwords) does not have, permissions for regular users to read or otherwise access., $ ls -l /etc/shadow, , $ chmod u+x file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod o+wx file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, , -rw-r----- 1 root shadow 869 2005-11-08 13:16 /etc/shadow, , $ chmod g-r file3, , Permissions:, , $ ls -l file3, , owner = Read & Write (rw-), , Add read, write and execute to everyone:, , group = Read (r--), , $ chmod ugo+rwx file4, , other = None (---), , $ ls -l file4, , Ownership:, owner = root, , -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, , group = shadow, , $, chmod with Numbers, , chmod with Letters, Usage: chmod {options} filename, Options, , 96, , -rw----r-- 1 user user 0 Nov 19 20:13 file3, , Definition, , U, , owner, , G, , group, , O, , other, , A, , all (same as ugo), , X, , execute, , W, , write, , R, , read, , +, , add permission, , -, , remove permission, , =, , set permission, , Usage: chmod {options} filename, Options, , Definition, , #--, , owner, , -#-, , group, , --#, , other, , 1, , execute, , 2, , write, , 4, , read, , Owner, Group and Other is represented by three numbers., To get the value for the options determine the type of, access needed for the file then add., For example if need a file that has -rw-rw-rwx permissions, will use the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Owner, read & write, , Group, read & write, , 4+2=6, , Other, read, write & execute, , 4+2=6, , 4+2+1=7, , Another example if you want a file that has --w-r-x--x, permissions you will use the following:, , write, 2, , Group, read & execute, 4+1 = 5, , Other, execute, 1, , $ chmod 251 filename, Here are a few examples of chmod usage with numbers, (try these out on your system)., First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, Add owner execute bit:, $ chmod 744 file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod 647 file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, $ chmod 604 file3, $ ls -l file3, -rw----r-- 1 user user 0 Nov 19 20:13 file3, Add read, write and execute to everyone:, $ chmod 777 file4, $ ls -l file4, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, chmod with sudo, , -rw-r--r-- 1 root root 550 2005-11-13 19:45 /usr/local/bin/, somefile, $ sudo chmod o+x /usr/local/bin/somefile, $ ls -l /usr/local/bin/somefile, -rw-r--r-x 1 root root 550 2005-11-13 19:45 /usr/local/, bin/somefile, $, Recursive permission changes, To change the permissions of multiple files and directories, with one command. Please note the warning in the chmod, with sudo section and the Warning with Recursive chmod, section., Recursive chmod with -R and sudo, To change all the permissions of each file and folder under, a specified directory at once, use sudo chmod with -R, $ sudo chmod 777 -R /path/to/someDirectory, , total 0, , $, , $ ls -l /usr/local/bin/somefile, , $, , $ chmod 667 filename, , Owner, , Please be careful when using sudo!), , $ ls -l, total 3, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file2, Recursive chmod using find, pipemill, and sudo, To assign reasonably secure permissions to files and, folders/directories, it's common to give files a permission, of 644, and directories a 755 permission, since chmod -R, assigns to both. Use sudo, the find command, and a, pipemill to chmod as in the following examples., To change permission of only files under a specified, directory., $ sudo find /path/to/someDirectory -type f -print0 | xargs, -0 sudo chmod 644, user@host:/home/user$ ls -l, total 3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, To change permission of only directories under a specified, directory (including that directory):, $ sudo find /path/to/someDirectory -type d -print0 | xargs, -0 sudo chmod 755, $ ls -l, , total 3, Changing permissions on files that do not have ownership, of: (Note that changing permissions the wrong way on the, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, wrong files can quickly mess up the system a great deal!, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 97
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drwxr-xr-x 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, Warning with Recursive chmod, WARNING: Although it's been said, it's worth mentioning, in context of a gotcha typo. Please note, Recursively, deleting or chown-ing files are extremely dangerous. You, will not be the first, nor the last, person to add one too, many spaces into the command. This example will hose, your system:, $ sudo chmod -R / home/john/Desktop/tempfiles, Note the space between the first / and home.You have, been warned., Changing the file owner and group, A file's owner can be changed using the chown command., For example, to change the foobar file's owner to tux:, $ sudo chown tux foobar, To change the foobar file's group to penguins, you could, use either chgrp or chown with special syntax:, $ sudo chgrp penguins foobar, $ sudo chown :penguins foobar, Finally, to change the foobar file's owner to tux and the, group to penguins with a single command, the syntax, would be:, $ sudo chown tux:penguins foobar, Note that, by default, you must use sudo to change a, file's owner or group., Difference between chown and chgrp, 1) Chown command is used to change ownership as well, as group name associated to different one, where as, chgrp can change only group associated to it., 2) Many people say that regular user only able to use, chgrp to change the group if the user belongs to them., But it's not true a user can use chown and chgrp, irrespective to change group to one of their group, because chown is located in /bin folder so every can, use it with some limited access., umask - Set default permissions, The umask command controls the default permissions, given to a file when it is created., It uses octal notation to express a mask of bits to be, removed from a file's mode attributes., [me@linuxbox ~]$ rm -f foo.txt, [me@linuxbox ~]$ umask, 0002, [me@linuxbox ~]$ > foo.txt, [me@linuxbox ~]$ ls -l foo.txt, -rw-rw-r-- 1 me me 0 2008-03-06 14:53 foo.txt, , we ran the umask command without an argument to see, the current value. It responded with the value 0002 (the, value 0022 is another common default value), which is the, octal representation of our mask. We next create a new, instance of the file foo.txt and observe its permissions., We can see that both the owner and group both get read, and write permission, while everyone else only gets read, permission. The reason that world does not have write, permission is because of the value of the mask., $ rm foo.txt, $ umask 0000, $ > foo.txt, $ ls -l foo.txt, -rw-rw-rw- 1 me me 0 2008-03-06 14:58 foo.txt, When we set the mask to 0000 (effectively turning it off),, we see that the file is now, world writable. To understand how this works, we have to, look at octal numbers again., If we take the mask and expand it into binary, then compare, it to the attributes., Original file mode, , --- rw- rw- rw-, , Mask, , 000 000 000 010, , Result, , --- rw- rw- r--, , Ignore for the moment the leading zeros (we'll get to those, in a minute) and observe that, where the 1 appears in our mask, an attribute was removedin this case, the the world, write permission. That's what the mask does. Everywhere, a 1 appears in the binary value, of the mask, an attribute is unset. If we look at a mask, value of 0022, we can see what it does:, Original file mode, , --- rw- rw- rw-, , Mask 000 000 010 010, Result, , --- rw- r-- r--, , Again, where a 1 appears in the binary value, the, corresponding attribute is unset. Play with some values, (try some sevens) to get used to how this works. When, you're done, remember to clean up:, $ rm foo.txt; umask 0002, The Tar command, The tar (i.e., tape archive) command is used to convert a, group of files into an archive., An archive is a single file that contains any number of, individual files plus information to allow them to be, restored to their original form by one or more extraction, programs. Archives are convenient for storing files as well, as for for transmitting data and distributing programs., Moreover, they are very easy to work with, often much, more so than dealing with large numbers of individual files., , We first removed any old copy of foo.txt to make sure we, were starting fresh. Next,, 98, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Although tar was originally designed for backups on, magnetic tape, it can now be used to create archive files, anywhere on a file system. Archives that have been created, with tar are commonly referred to as tar balls., Unlike some other archiving programs, and consistent with, the Unix philosophy that each individual program should, be designed to do only one thing but do it well, tar does, not perform compression. However, it is very easy to, compress archives created with tar by using specialized, compression utilities., tar's basic syntax is, tar option(s) archive_name file_name(s), tar has numerous options, many of which are not, frequently used. Unlike many commands, tar requires the, use of at least one option, and usually two or more are, necessary., tar files are created by using both the -c and -f options., The former instructs tar to create an archive and the latter, indicates that the next argument (i.e., piece of input data, in a command) will be the name of the new archive file., Thus, for example, the following would create an archive, file called file.tar from the three files namedfile1, file2 and, file3 that are located in the current directory (i.e., the, directory in which the user is currently working):, tar -cf file.tar file1 file2 file3, It is not absolutely necessary that the new file have the, .tar extension; however, the use of this extension can be, is very convenient because it allows the type of file to be, visually identified. It is necessary, however, that the -f option, be the final option in a sequence of contiguous, singleletter options; otherwise, the system will become confused, as to the desired name for the new file and will use the, next option in the sequence as the name., The -v (i.e., verbose) option is commonly used together, with the -c and -f options in order to display a list of the, files that are included in the archive. In such case, the, above example would become, tar -cvf file.tar file1 file2 file3, tar can also be used to make archives from the contents, of one or more directories. The result is recursive; that is,, it includes all objects (e.g., directories and files) within, each level of directories. For example, the contents of two, directories named dir1 and dir2 could be archived into a, file named dir.tar with the following:, tar -cvf dir.tar dir1 dir2, It is often convenient to use tar with a wildcard (i.e., a, character which can represent some specific class of, characters or sequence of characters). The following, example uses the star wildcard (i.e., an asterisk), which, represents any character or sequence of characters, to, create an archive of every object in the current directory:, tar -cf *, By default, tar creates an archive of copies of the original, files and/or directories, and the originals are retained., , However, they can be removed when using tar by adding, the --remove-files option., As it has no compression and decompression capabilities, of its own, tar is commonly used in combination with an, external compression utility. A very handy feature of the, GNU version (which is standard on Linux) is the availability, of options that will cause standard compression programs, to compress a new archive file as soon as it has been, created. They are -j (for bzip2), -z (for gzip) and -Z (for, compress). Thus, for example, the following would create, an archive named files.tar.bz2 of the files file4, file5 and, file6 that is compressed using bzip2:, tar -cvjf files.tar.bz2 file4 file5 file6, tar can also be used for unpacking tar files. However, before, doing this, there are several steps that should be taken., One is to confirm that sufficient space is available on the, hard disk drive (HDD). Another is to move to an empty, directory (which usually involves creating one with an, appropriate name) to prevent the reconstituted files from, cluttering up the current directory and overwriting any files, or directories with same names that are in it. In addition, if, the archive has been compressed, it must first be, decompressed using the appropriate decompression, program (which can usually be determined by the filename, extension)., In order to unpack a tar file, the -x (for extract) and -f, options are required. It is also common to add the -v option, to provide a running listing of the files being unpacked., Thus, for example, to unpack the archive file.tar created in, a previous example the following would be used:, tar -xvf file.tar, Just as options are available to allow three compression, programs to automatically compress newly created tar, files, the same options can be used to have the, compression programs automatically decompress tar files, prior to extraction. Thus, for instance, the following would, decompress and extract the contents of the compressed, archive files.tar.bz2 that was created in an above example:, tar -xjvf files.tar.bz2, Files can be added to an existing archive using the -r, option. As is always the case with tar, it is also necessary, to use the -f option to indicate that the followingstring (i.e.,, sequence of characters) is the name of the archive. For, example, the following would append a file named file7 to, file.tar:, tar -rf file.tar file7, The --delete option allows specified files to be completely, removed from a tar file (except when the tar file is on, magnetic tape). However, this is different from an, extraction, as copies of the removed files are not made, and placed in the current directory. Thus, for example, the, files file1 and file2 can be removed from file.tar with the, following:, tar -f file.tar --delete file1 file2, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 99
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The -t option tells tar to list the contents of an, uncompressed archive without performing an extraction., Thus, the following would list the contents of file.tar:, tar -tf file.tar, Input, output and error redirection in linux, Input/output redirection means the text that is showing on, the screen while you are running any command(program)in, the shell, that information can be redirect elsewhere and, even it can store this output in a file or can be print directly., This function called Redirection, and can also redirect the, input of program., In Linux systems everything consider as a file., A file descriptor is number that is associated with every, file, When run a program in shell ( i.e when execute a command, ) on the back end Linux access 3 special files., Standard input - 0 file descriptor( example = mouse,), Standard output - 1 file descriptor( example = Screen), Standard error output - 2 file descriptor(example=Screen), So it can redirect these files to other files. If user redirect, standard output (Descriptor = 1) to the printer, instead of, showing these outputs on the screen and the computer, start getting print on paper., Output Redirection, Output Redirection is most commonly used, when execute, a command it's normally appears on the terminal . If extract, any tar file you will notice all the output scrolls down rapidly., And can redirect this output in a file for inspecting the, output or can send anybody via email. This is called Output, Redirection. Using this operator '>' in shell can redirect, the output in a file., Example :, $ ls > output.txt, $ cat output.txt, bin, boot, , root, sbin, selinux, srv, sys, tmp, usr, var, $, If output.txt file is already exit then '>' operator, will overwrite the file for append more output, into output.txt use '>>' instead of '>'., Input Redirection, You can redirect your input by using '<' operator. Cannot, run input redirection on all programs or commands. And, can use only with that programs or commands that accept, Input from keyboard., Example : user going to send an email and already have, Template of that email. and can put template in the email, body using input redirect., $ mail ali < mail_template.txt, above command launch email program with, mail_template.txt contents., Now due to advancement in GUI, and also lots of good, email clients, method is rarely used., Error Redirection, Error Redirection is very helpful when in trouble. In this, case user trying to open a file that is not readable for my, user will get permission denied errors. it will redirect these, error into error.txt file., Example :, $ cat ali.txt 2> /home/H.Ali/error.txt, $ cat /home/H.Ali/error.txt, cat: ali.txt: Permission denied, , etc, , In the above command 2 is descriptor of error redirection, file by typing '2>' you are saying redirect any kind of error, to the file error.txt, , home, , Pipes ' | ' in Linux, , lib, , Linux pipes allow us connect output stream of 'command, a' to input stream of 'command b'. here in my case i will, pipe cat commands output into less as input., , dev, , lib64, lost+found, media, mnt, opt, output.txt, proc, 100, , Example : cat /var/log/messages | less, we can also use pipe for searching strings specially from, large text files., cat /var/log/messages | grep kernal | less, grep is a line searcher it will search lines for specific piece, of text., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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above command will shearch a keywork 'kernel' with grep, and then pipe it again to less., Pipes in linux, A pipe is a form of redirection that is used in Linux and, other Unix-like operating systems to send the output of, one program to another program for further processing., Redirection is the transferring of standard output to some, other destination, such as another program, a file or a, printer, instead of the display monitor (which is its default, destination). Standard output, sometimes abbreviated, stdout, is the destination of the output from command line, (i.e., all-text mode) programs in Unix-like operating, systems., Pipes are used to create what can be visualized as a, pipeline of commands, which is a temporary direct, connection between two or more simple programs. This, connection makes possible the performance of some highly, specialized task that none of the constituent programs, could perform by themselves. A command is merely an, instruction provided by a user telling a computer to do, something, such as launch a program. The command line, programs that do the further processing are referred to as, filters., This direct connection between programs allows them to, operate simultaneously and permits data to be transferred, between them continuously rather than having to pass it, through temporary text files or through the display screen, and having to wait for one program to be completed before, the next program begins., Examples, A pipe is designated in commands by the vertical bar, character, which is located on the same key as the, backslash on U.S. keyboards. The general syntax for, pipes is:, command_1 | command_2 [| command_3 . . . ], This chain can continue for any number of commands or, programs., A very simple example of the benefits of piping is provided, by the dmesg command, which repeats the startup, messages that scroll through the console(i.e., the all-text,, full-screen display) while Linux is booting (i.e., starting, up). dmesg by itself produces far too many lines of output, to fit into a single screen; thus, its output scrolls down the, screen at high speed and only the final screenful of, messages is easily readable. However, by piping the output, of dmesg to the filter less, the startup messages can, conveniently be viewed one screenful at a time, i.e.,, dmesg | less, , The same result could be achieved by first redirecting the, output of dmesg to a temporary file and then displaying, the contents of that file on the monitor. For example, the, following set of two commands uses the output redirection, operator (designated by a rightward facing angle bracket), to first send the output of dmesg to a text file called tempfile1, (which will be created by the output redirection operator if, it does not already exist), and then it uses another output, redirection operator to transfer the output of tempfile1 to, the display screen:, dmesg > tempfile1, tempfile1 > less, However, redirection to a file as an intermediate step is, clearly less efficient, both because two separate, commands are required and because the second, command must await the completion of the first command, before it can begin., The use of two pipes to chain three commands together, could make the above example even more convenient for, some situations. For example, the output of dmesg could, first be piped to the sort filter to arrange it into alphabetic, order before piping it to less:, dmesg | sort -f | less, The -f option tells sort to disregard case (i.e., whether, letters are lower case or upper case) while sorting., Likewise, the output of the ls command (which is used to, list the contents of a directory) is commonly piped to the, the less (or more) command to make the output easier to, read, i.e.,, ls -al | less, or, ls -al | more, ls reports the contents of the current directory (i.e., the, directory in which the user is currently working) in the, absence of any arguments (i.e., input data in the form of, the names of files or directories). The -l option tells ls to, provide detailed information about each item, and the aoption tells ls to include all files, including hidden files, (i.e., files that are normally not visible to users). Because, ls returns its output in alphabetic order by default, it is not, necessary to pipe its output to the sort command (unless, it is desired to perform a different type of sorting, such as, reverse sorting, in which case sort's -r option would be, used)., This could just as easily be done for any other directory., For example, the following would list the contents of the /, bin directory (which contains user commands) in a, convenient paged format:, , less allows the output of dmesg to be moved forward one, ls -al /bin | less, screenful at a time by pressing the SPACE bar and back, The following example employs a pipe to combine the ls, one screenful at a time by pressing the b key. The command, and the wc (i.e., word count) commands in order to show, can be terminated by pressing the q key. (The more, how many filesystem objects (i.e., files, directories and, command could have been used here instead of less;, links) are in the current directory:, however, less is newer than more and has additional, functions, including the ability to return to previous pages, ls | wc -l, of the output.), 101, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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ls lists each object, one per line, and this list is then piped, to wc, which, when used with its -l option, counts the, number of lines and writes the result to standard output, (which, as usual, is by default the display screen)., The output from a pipeline of commands can be just as, easily redirected to a file (where it is written to that file) or, a printer (where it is printed on paper). In the case of the, above example, the output could be redirected to a file, named, for instance, count.txt:, ls | wc -l > count.txt, The output redirection operator will create count.txt if it, does not exist or overwrite it if it already exists. (The file, does not, of course, require the .txt extension, and it could, have just as easily been named count, lines or anything, else.), The following is a slightly more complex example of, combining a pipe with redirection to a file:, echo -e "orange \npeach \ncherry" | sort > fruit, The echo command tells the computer to send the text, that follows it to standard output, and its -e option tells the, computer to interpret each \nas the newline symbol (which, is used to start a new line in the output). The pipe redirects, the output from echo -e to the sort command, which, arranges it alphabetically, after which it is redirected by, the output redirection operator to the file fruit., As a final example, and to further illustrate the great power, and flexibility that pipes can provide, the following uses, three pipes to search the contents of all of the files in, current directory and display the total number of lines in, them that contain the string Linux but not the stringUNIX:, cat * | grep "Linux" | grep -v "UNIX" | wc -l, In the first of the four segments of this pipeline, the cat, command, which is used to read and concatenate (i.e.,, string together) the contents of files, concatenates the, contents of all of the files in the current directory. The, asterisk is a wildcard that represents all items in a specified, directory, and in this case it serves as an argument to cat, to represent all objects in the current directory., The first pipe sends the output of cat to the grep, command, which is used to search text. The Linux, argument tells grep to return only those lines that contain, the string Linux. The second pipe sends these lines to, another instance of grep, which, in turn, with its -v option,, eliminates those lines that contain the string UNIX., Finally, the third pipe sends this output to wc -l, which, counts the number of lines and writes the result to the, display screen., Find hardware devices in Ubuntu Linux with lshw, There are a variety of ways to find out what kind of, hardware running in linux, but one of the easiest ways, that gives a large amounts of valuable data is to use lshw, (Hardware Lister). And lshw is installed by default., Testing of lshw command as shown below…, $ sudo lshw, 102, , Installing, lshw is available on most package management systems., If use APT (Debian-based distros: Ubuntu, Linux Mint, and, others), run the following command in terminal:, $ sudo apt-get install lshw, If use Yum (Red Hat, Fedora, CentOS, Yellow Dog Linux,, etc), run the following command in terminal:, $ sudo yum install lshw, If these instructions don't match your package manager,, look for specific instructions on the lshw site to get it, installed on your system., Using lshw, If you just run lshw by itself on the command line, your, screen will be flooded with large amounts of text., Fortunately, it is very easy to get lshw to give you output, that meets your needs., Shorter output, If you just quickly want to quickly find the chipset version, of a piece of hardware is, you can run the following to, provide a very short output that should give you what you, need:, $ sudo lshw -short, For example, here is a sample when I run this on my Dell, Studio 17 laptop (Note: I've removed a large portion of the, output to make this fit):, $ sudo lshw -short, Device class, , Description, , system, , Studio 1735, , bus, , 0H275K, , memory, , 64KiB BIOS, , processor, , Intel(R) Core(TM)2 Duo CPU, T8100 @ 2.10GHz, , memory, , 32KiB L1 cache, , memory, , 3MiB L2 cache, , memory, , 4GiB System Memory, , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , display, , Mobility Radeon HD 3650, , multimedia, , RV635 Audio device [Radeon HD, 3600 Series], , multimedia, , 82801H (ICH8 Family) HD, Audio Controller, , eth1 network, , BCM4322 802.11a/b/g/n, Wireless LAN Controller, , eth0 network, , NetLink BCM5784M Gigabit, Ethernet PCIe, , /dev/sda disk, 250GB WDC WD2500BEVS-7, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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This of course leaves out a lot of detail. Maybe we just, need to store the data somewhere so it's easier to work, with., Storing output to a file, If you'd like to put all the lshw output into a file, you can do, so easily from the terminal with output redirection., $ sudo lshw > hardware.txt, This will run the lshw command and put all the output into, a file in the current directory called hardware.txt. Note, that this will replace any file in the current directory called, hardware.txt. Make sure that you either backup the file,, give the output file a unique name, or are prepared to lose, that original file's information., Now you can open the hardware.txt file with your favorite, editor and look through the informations., , Creating HTML or XML Output, lshw has the ability to format its output in either HTML or, XML. This can be very helpful if you want to post your, hardware specs somewhere online to be viewed or to send, the data to a storage system., To create HTML output, simply give lshw the -html, option:, $ sudo lshw -html > hardware.html, This will format the output into a HTML document and, save the output in a file called hardware.html., Creating XML is done with the -xml option:, $ sudo lshw -xml > hardware.xml, Like before, this will output the document in XML format, and save it to hardware.xml., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 103
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Date command examples to display and set, system date time, Date command is helpful to display date in several formats., It also allows you to set systems date and time., Here few examples on how to use date command with, practical examples., When execute date command without any option, it will, display the current date and time as shown below., $ date, Mon May 20 22:02:24 PDT 2013, 1. Display Date from a String Value using -date, Option, If you have a static date or time value in a string, you can, use -d or -date option to convert the input string into date, format as shown below., Please note that this doesn't use the current date and, time value. Instead is uses the date and time value that, you pass as string., The following examples takes an input date only string,, and displays the output in date format. If you don't specify, time, it uses 00:00:00 for time., $ date --date="12/2/2014", Tue Dec 2 00:00:00 PST 2014, , 3. Get Relative Date Using -date option, You can also use date command to get a future date using, relative values., For example, the following examples gets date of next, Monday., $ date --date="next mon", Mon May 27 00:00:00 PDT 2013, If string=@is given to date command, then date command, convert seconds since the epoch (1970-01-01 UTC) to a, date., It displays date in which 5 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@5, Wed Dec 31 16:00:05 PST 1969, It displays date in which 10 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@10, Wed Dec 31 16:00:10 PST 1969, It displays date in which 1 minute (i.e. 60 seconds) is, elapsed since epoch 1970-01-01 UTC:, $ date --date=@60, Wed Dec 31 16:01:00 PST 1969, , $ date --date="2 Feb 2014", , 4. Display past date, , Sun Feb 2 00:00:00 PST 2014, , You can display a past date using the -date command., Few possibilities are shown below., , $ date --date="Feb 2 2014", Sun Feb 2 00:00:00 PST 2014, The following example takes an input date and time string,, and displays the output in date format., , $ date --date='3 seconds ago', Mon May 20 21:59:20 PDT 2013, $ date --date="1 day ago", , $ date --date="Feb 2 2014 13:12:10", , Sun May 19 21:59:36 PDT 2013, , Sun Feb 2 13:12:10 PST 2014, , $ date --date="yesterday", , 2. Read Date Patterns from a file using -file option, This is similar to the -d or -date option that we discussed, above. But, you can do it for multiple date strings. If you, have a file that contains various static date strings, you, can use -f or -file option as shown below., In this example, we can see that datefile contained 2 date, strings. Each line of datefile is parsed by date command, and date is outputted for each line., $ cat datefile, , $ date --date="1 month ago", Sat Apr 20 21:59:58 PDT 2013, $ date --date="1 year ago", Sun May 20 22:00:09 PDT 2012, 5. Set Date and Time using -set option, You can set date and time of your system using -s or -set, option as shown below.., , Sept 9 1986, Aug 23 1987, , In this example, initially it displayed the time as 20:09:31., We then used date command to change it to 21:00:00., , $ date --file=datefile, Tue Sep 9 00:00:00 PDT 1986, Sun Aug 23 00:00:00 PDT 1987, , 104, , Sun May 19 22:00:26 PDT 2013, , $ date, Sun May 20 20:09:31 PDT 2013, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ date -s "Sun May 20 21:00:00 PDT 2013", Sun May 20 21:00:00 PDT 2013, $ date, , The timestamp of datefile is changed using touch command. This was done few seconds after the above date, command's output., $ touch datefile, , Sun May 20 21:00:05 PDT 2013, 6. Display Universal Time using -u option, You can display date in UTC format using -u, or -utc, or universal option as shown below., $ date, Mon May 20 22:07:53 PDT 2013, $ date -u, Tue May 21 05:07:55 UTC 2013, , The current time after the above touch command is, 20:26:12, $ date, Sun May 20 20:26:12 PDT 2013, Finally, use the date command -r option to display the, last modified timestamp of a file as shown below. In this, example, it displays last modified time of datefile as, 20:25:57. It is somewhere between 20:25:48 and 20:26:12, (which is when we execute the above touch command to, modify the timestamp)., , 7. Display Last Modification Time using -r option, , $ date -r datefile, , In this example, the current time is 20:25:48, , Sun May 20 20:25:57 PDT 2013, , $ date, , 8. Various Date command formats, , Sun May 20 20:25:48 PDT 2013, , You can use formatting option to display date command, in various formats using the following syntax:, $ date +%<format-option>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 105
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Command, , Description, , • apropos whatis, , Show commands pertinent to string. See, also threadsafe, , • man -t ascii | ps2pdf - > ascii.pdf, , make a pdf of a manual page, , which command, , Show full path name of command, , time command, , See how long a command takes, Start stopwatch. Ctrl-d to stop. See also, sw, , • time cat, dir navigation, • cd -, , Go to previous directory, , • cd, , Go to $HOME directory, , (cd dir && command), , Go to dir, execute command and return to, current dir, Put current dir on stack so you can popd, back to it, , • pushd ., file searching, • alias l='ls -l --color=auto', , quick dir listing. See also l, , • ls -lrt, , List files by date. See also newest and, find_mm_yyyy, , • ls /usr/bin | pr -T9 -W$COLUMNS, , Print in 9 columns to width of terminal, , find -name '*.[ch]' | xargs grep -E 'expr', , Search 'expr' in this dir and below. See, also findrepo, , find -type f -print0 | xargs -r0 grep -F 'example', , Search all regular files for 'example' in, this dir and below, , find -maxdepth 1 -type f | xargs grep -F, 'example', , Search all regular files for 'example' in, this dir, , find -maxdepth 1 -type d | while read dir; do, echo $dir; echo cmd2; done, , Process each item with multiple, commands (in while loop), , • find -type f ! -perm -444, , Find files not readable by all (useful for, web site), , • find -type d ! -perm -111, , Find dirs not accessible by all (useful for, web site), , • locate -r 'file[^/]*\.txt', , Search cached index for names. This re is, like glob *file*.txt, , • look reference, , Quickly search (sorted) dictionary for, prefix, , • grep --color reference /usr/share/dict/words, , Highlight occurances of regular, expression in dictionary, , archives and compression, gpg -c file, , Encrypt file, , gpg file.gpg, , Decrypt file, , tar -c dir/ | bzip2 > dir.tar.bz2, , Make compressed archive of dir/, , bzip2 -dc dir.tar.bz2 | tar -x, , Extract archive (use gzip instead of bzip2, for tar.gz files), , tar -c dir/ | gzip | gpg -c | ssh user@remote 'dd Make encrypted archive of dir/ on remote, of=dir.tar.gz.gpg', machine, , 106, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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set operations (Note you can export LANG=C for speed. Also these assume no, duplicate lines within a file), sort file1 file2 | uniq, , Union of unsorted files, , sort file1 file2 | uniq -d, , Intersection of unsorted files, , sort file1 file1 file2 | uniq -u, , Difference of unsorted files, , sort file1 file2 | uniq -u, , Symmetric Difference of unsorted files, , join -t'\0' -a1 -a2 file1 file2, , Union of sorted files, , join -t'\0' file1 file2, , Intersection of sorted files, , join -t'\0' -v2 file1 file2, , Difference of sorted files, , join -t'\0' -v1 -v2 file1 file2, , Symmetric Difference of sorted files, , math, • echo '(1 + sqrt(5))/2' | bc -l, , Quick math (Calculate φ). See also bc, , • seq -f '4/%g' 1 2 99999 | paste -sd-+ | bc -l, , Calculate π the unix way, , •, , echo 'pad=20; min=64;, (100*10^6)/((pad+min)*8)' | bc, , More complex (int) e.g. This shows max, FastE packet rate, , •, , echo 'pad=20; min=64; print, (100E6)/((pad+min)*8)' | python, , Python handles scientific notation, , •, , echo 'pad=20; plot [64:1518], (100*10**6)/((pad+x)*8)' | gnuplot -persist, , Plot FastE packet rate vs packet size, , • echo 'obase=16; ibase=10; 64206' | bc, , Base conversion (decimal to, hexadecimal), , • echo $((0x2dec)), , Base conversion (hex to dec) ((shell, arithmetic expansion)), , • units -t '100m/9.58s' 'miles/hour', , Unit conversion (metric to imperial), , • units -t '500GB' 'GiB', , Unit conversion (SI to IEC prefixes), , • units -t '1 googol', , Definition lookup, , • seq 100 | paste -s -d+ | bc, , Add a column of numbers. See also add, and funcpy, , calendar, • cal -3, , Display a calendar, , • cal 9 1752, , Display a calendar for a particular month, year, , • date -d fri, , What date is it this friday. See also day, , •, , [ $(date -d '12:00 today +1 day' +%d) = '01' ], || exit, , exit a script unless it's the last day of the, month, , • date --date='25 Dec' +%A, , What day does xmas fall on, this year, , • date --date='@2147483647', , Convert seconds since the epoch (197001-01 UTC) to date, , • TZ='America/Los_Angeles' date, , What time is it on west coast of US (use, tzselect to find TZ), , •, , date --date='TZ="America/Los_Angeles" 09:00, next Fri', , What's the local time for 9AM next Friday, on west coast US, , locales, • printf "%'d\n" 1234, , Print number with thousands grouping, appropriate to locale, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 109
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.29, , MS WORD 2010 THEORY, Objectives : At the end of this lesson you shall be able to, • state what is MS Office, • brief what is MS Word and starting steps, • explain various screen blocks of MS Word, • explain procedures to create, save, print a documentl., Microsoft office is a application software package, introduced by Microsoft Corporation. MS Office consists, of the following popular packages :, , The Ribbon tab of Word has eight major parts viz. File,, Home, Insert, Page Layout, References, Mailings,, Review and View., , •, , Microsoft Word, , •, , Microsoft Excel, , •, , Microsoft Powerpoint, , •, , Microsoft Access, , •, , Microsoft Outlook, , File tab of the ribbon is useful to create a new file, a, blank or a template page as required. Ctrl + N always, create a new blank document in Office Package. The, documents so created can be saved as default word, document or given compatible format. Furthermore,, permission for accessing a documents can be fixed,, share a document on a network, even manage a, document to be compatible with previous and external, versions. Print option makes the document to get a hard, copy or a pdf format according to the installed printer, features. Recently opened files can also be viewed to, find it easy to work again. Help on word is there in the, same tab., , Word 2010, It is a word processor package that helps to create and, edit a document. It is the most known word processor of, nowadays. It makes professional looking documents by, providing a comprehensive set of tools for creating and, formatting a document, memos, letters, reports,, brochures, business documents and even internet web, pages., Starting Word, , Fig. 2 Home Tab, , Fig 2, , Fig 1 - Default page layout, , Copa 1182902, , Click on the Start > (windows Logo) All programmes >, Microsoft office > Microsoft Word. MS Word opens along, with a default blank document with default settings page, layout., , Home tab has clipboard options including cut, copy, paste, and paste special. The Font block has all the options of, setting fonts, size, superscript, subscript, bold, italic,, underline, strikethrough, font colors, etc., , Fig 1, , Fig 3 - Paragraph Group, , Unlike previous version, MS Office 2010 has a common, set of features for all the components. It makes it easy, to understand and common utilities to remain available, on all the packages of MS Office including Word, Excel,, PowerPoint, Access, etc. Many features are redesigned, so as enabling the diverted users of other packaged can, afford with. These enhancements and utilities in Word, 2010 are described as below., , Copa 1182903, , Copa 1182901, , Fig 3, , Paragraph group creates the formatting paragraphs with, alignments left, right, center, justify and indentations, para, and line spacing. Line and page breaks allows to create, pagination options and exceptions of formatting., , Copyright @ NIMI Not to be Republished, , 113
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Fig 4 - Styles and Editing Group, , Symbols group inserts symbols of equations like math, equations or symbols like currency, math symbols, etc., Copa 1182904, , Fig 4, , Fig 8 - Themes and Page Setup Group, , Fig 8, , Copa 1182905, , Fig 5, , Page group makes cover pages, blank pages insertion, and page breaks. Tables group helps to insert a table in a, text document with ready specified row-column set or a, customized table format. Illustration group inserts pictures, from external sources, cliparts, shapes, smart art, charts, of data, even screenshot into the text document., Fig 6 - Links and Header/Footer Groups, , Page Layout tab has five major groups. Themes block, creates predefined template setup using themes on, documents. Even new themes customized can be, created and saved for future use., Page setup group has features on margin around, page, orientation i.e. vertical or horizontal, paper size, columns, to display, breaks, line numbers and hyphenation., Fig 9 - Page Background and Paragraph Group, Fig 9, Copa 1182909, , The Insert tab has 7 groups. Fig 5 - Pages, Tables and, Illustrations blocks (Fig 5), , Copa1182908, , The Styles group allows preformatted text styles like, Heading styles, Paragraph styles, Subtitles, etc. Custom, styles can also be stored with altered specifications. The, Editing group used to select specific area, find and / or, replace option in a specified area in text., , Page Background group creates a watermark, page, Background color and page borders. Paragraph block, has specified options already discussed in Home ->, Paragraph group., Copa1182906, , Fig 6, , Fig 10 - Arrange Group, , Fig 10, Copa 11829010, , Links group creates hyperlink on texts, bookmarks and, cross references in a document., The header and footer group inserts header, footer to be, appearing on every page and page numbers to display, as to placement area., , The arrange group creates position of objects, text, elements, text wrapping, arranging objects, aligning of, objects, grouping and transformations., , Fig 7 - Text and Symbols block, , Fig 7, , References tab has six blocks., , Text group allows creating text box, quick parts likely to, create brochures, designed text as WordArt, paragraph, styles, a signature line, date and time and an object insert, option., 114, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , Copa 11829011, , Fig 11, , C, , 1182907, , Fig 11 - TOC and Footnotes Group
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Fig 15 - Write and Insert fields Group, , Fig 15, Copa 11829015, , Table of contents creates the TOC of a particular, publication document automatically and upon, modifications updatable. Footnotes tab creates footnotes, of a page, block area which includes explanatory phrases, or references. Endnote makes the note at the end of the, document., Fig 12 - Citations, Bibilography and Captions Group, , Copa 11829012, , Fig 12, , Citation and Bibliography makes an external source as, citation, reference tables and credits of authors related, to the publication. Captions tab inserts a caption, table, of figures, cross references inside a text., , While writing a letter, it has many parts, which this mail, merge creates fields of Address Block, Greetings Line,, Merged field of content, labels, etc., Fig 16 - Preview Results and Finish Groups, Fig 16, , Copa 11829016, , Fig 13 - Index and Table of Authorities Group, , Copa 11829013, , Fig 13, , Index enters a value on a main topic or sub topic and, create the index accordingly. Table of authorities has, the citation mark includes the list of the cases, statutes, and other authorities cited in the document., , On successful completion of mail merge, it can be, previewed and checked for errors for each recipients, and edit accordingly. Upon validation the mail merge, gets finished., Fig 17 - Proofing and Language Groups, Fig 17, , Fig 14 - Create and Mailmerge Groups, , Mailings tab used to create mailing of a letter or order, using common mailing features. Create block makes, envelopes print using predefined formats as well as, custom formats. Labels can also be printed to which the, delivery address is mentioned., Mail merge block is used to create mail merge of a letter,, email. If a common letter is created and to be sent to, many recipients, this option allows to create an Address, block where the recipient's info should appear. Even, selective recipients can be listed as well as a new, recipient list can be created., , Copa 11829017, , Copa 11829014, , Fig 14, , Review tab here is used for the various document areas, to be reviewed. Proofing makes easier to check Spelling, and Grammar of a document. Accidental errors can be, corrected here. Research refines the search not only, inside the document, but also the referenced documents., Thesaurus identifies the completeness of the document, using the standard language compatibility of the region, like English UK or English USA etc. Word count shows, the analysis of the document as total words, total, characters, with and without spaces, no. of paragraphs,, lines, etc. Here Text blocks can also be included for, such analysis., Language Block helps to translate a page into the, installed other languages and to change the proofing, language. It requires the direct translator service from, Microsoft Online., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , 115
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Fig 18 - Comments & Tracking Group, , Fig 20 - Document views and show Groups, , Fig 18, , Comments group inserts a comment for a specific, paragraph or text block., Tracking group finds the changes made on a document, by other authors in a protected mode. For example, if a, document is created by user X and edited by user Y, is, tracked separately with Track marks., Fig 19 - Changes, Compare and Protect Groups, , Copa 11829020, , Copa 11829018, , Fig 20, , View tab shows the way of displaying the word document., Document views have a Print Layout, a common view, of Word, Full Screen Reading, minimises the tabs and, ribbons to disappear and easy to read, Web Layout, which, previews a html compatible view, Outline, views the basic, version of document in mere text mode and Draft mode, for a text editing mode., The Rulers, Gridlines and Navigation Pane can be shown, or hidden according to user preferences., Fig 21 - Zoom / Window / Macro Groups, , Fig 19, , Changes hence made on the documents can either then, accepted or rejected. More than a document can be, compared for similarity using Compare. Also the, document can be protected from editing by other authors., , 116, , Copa 11829021, , Copa 11829019, , Fig 21, , Also the view of the page can be Zoomed to full page, two, pages view, 100% of the document and custom view. To, make easy editing a document the window can be split, into two, a new window for a document to cut paste, etc., can be created and all open word documents can be, arranged for view. While formatting the documents, for, repetition of commands the Macro option can be used. It, uses the Record option to store the set of commands and, repeat it again on other part of document or on another, document on a single click., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.6.30 to 1.6.37, COPA- Word Processing Software, Creating a file, save and other options, Objectives: At the end of this lesson you shall be able to, • explain how to create a new document, save and print, • state how to edit, format text and document styles, • brief using tables inside word document with data, • explain how to create styles in a document and save for future use, • explain Few unique features of Word 2010, • brief the mail merge processing, Fig 1 - File Info view, , Fig 3 - Print options in word, , Fig 1, Fig, 22, , Fig 3, , Copa 11829024, , Copa 11829022, , Fig 24, , Word 2010 new document can be created as usual with, Ctrl + N or through File menu New option. Basically the, file created is saved as a word document extended format, as docx in word file., Fig 2 - Save options in Word, , The saved documents can be printed using the File Menu, -> Print option and the installed printer support makes it, easy to get the document printed. If Adobe Acrobat, Professional is installed, the same document can be, stored as a PDF file for sharing purposes. Apart from, printing and storage, the file created can be published in, web as a web page or template that can be used for, future publications in same format., , Copa 11829023, , Fig 23, 2, Fig, , It can be saved using save as option in any compatible, format or old versions of office, like 2003 or earlier versions., Main utility of the word software is the creation of word, processing documents. It may be any of a format like, publication, letter, brochure, etc. Word supports all type, of formatting to design a text based presentation. Also it, supports output files in major accepted formats according, to industry standards., , Basic concepts to be noted while using Word are Text, properties. It includes Font type, Font size, Text Color,, and usual decorations of text. Also creating of paragraphs, styles are to be kept in mind. Paragraph alignment has, left, right, center and justified settings. Text elements, may contain items like ordered list, unordered list, subsection lists. They are found there paragraph formatting, block of Home Tab. Indenting of text for creating Quotes, is also there inside the same tab. According to the page, size, line spacing and paragraph spacing can be adjusted,, like before and after paragraph spaces, line heights, etc., The Styles can be predefined to use as ready to put on, places where it required. Standard templates are, available but it allows to create custom styles too., Tables can be inserted for various utilities. Normal table, has adjustable width and columns so it can simply inserted, with Insert > Table option directly., , Copyright @ NIMI Not to be Republished, , 117
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Fig 4 - Table insert wizard options, , FigFig, 276, , Fig 4, , In case of custom sized table is required, it can be created, using insert table / draw table options. Insert table allows, custom values for columns, width and other properties., Draw table creates custom table using a pen drawing tool, through which new table can be drawn according to the, available text contents., Customizable Quick Access Tool Bar, Word 2010's Quick Access Toolbar displays all the, commonly used options. It is located in the top left side, corner of the application window, near the office button., By default it displays the following three options, Save,, Undo and Redo, but is customizable and you may easily, add more options to it. (Fig 5), , Navigation Pane, In the previous versions of Microsoft Office, one has to, use the Ctrl+F hotkey to find any word or phrase from, within a document. Word 2010 has added a new magic to, this option, Ctrl+F now summons a Navigation Pane that, appears on the left side of the document. You will see the, three views available by clicking on their respective tabs,, the Heading View, Thumbnail Page View, and the Search, Result View. (Fig 7), Fig 7, , Fig 28, , Fig 26, , Copa 11829026, , Copa 11829028, , Fig 5, , Copa 11829027, , Copa 11829025, , Fig 25, , Paste Preview, , Customizable Ribbon Button, Apparently the Ribbon button in Word 2010 looks like the, one in Word 2007. But there is one big addition, you may, customize the word 2010's Ribbon button. In order to, customize the Ribbon button navigate to the following option, Office Button > Word Option > Customize Ribbon. (Fig 8), , It happens with most users that after copying and pasting, something into their document, they need to undo the, some changes. Word 2010 has made it easy for users,, now you may eliminate this unnecessary step by using, the paste preview option. It allows users to paste only the, values or the formatting. (Fig 6), 118, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished
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Improved Collaborations, , 8, FigFig29, , Copa 11829029, , Microsoft Word 2010 has a new feature called coauthoring. It allows more than one authors to edit a, document at the same time. Word 2010 tells you how, many authors are editing the document and their changes, can be viewed too. (Fig 9), , Fig 9, , Copa 11829030, , Fig 30, , Screen Capture Tool, , Copa 11829032, , Fig 10, Fig 31, , Fig Fig, 32 11, , Copa 11829031, , Word 2010 includes a feature called Screen Capturing,, now there is no need to use a third party or additional tool, to capture a screenshot in order to use it in Word, just, simply use Word 2010's built in tool to capture any area of, the screen. A Screenshot may be taken by navigating to, the following option Insert > Screenshot. (Fig 10), , The Background Removal Option, Artistic Effects, In Word 2010 users can now apply a number of snazzy, artistic effects to the pictures. In order to add the artistic, effects to your document, Navigate to the following option, Insert > Illustrations > Picture. Then browse and select, the picture you want, Once the picture is added to your, document, then the Picture Tools contextual tab is, displayed and you will be able to see the new Artistic, Effects drop down button over here. (Fig 11), , Office 2010 has an awesome option by the name of, Background Removal, which simply removes the, background of any image. Yes, you don't need Photoshop, anymore to remove the background. First insert the, picture in your Word document from the Insert > Picture, option. Then locate the Background Removal tool and get, rid of the background. (Fig 12), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 119
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Ligatures, , Copa 11829033, , Fig33, 12, Fig, , You might have heard about Ligatures. They make the, fonts look fancy and they are also used to keep letters, separate allowing you to search the text as if the font, were regular. Its true that not all fonts support ligatures,, but a large variety of the fonts supports them. You may, enable them from Font Preferences > advanced, then select, the standard only option in the ligatures drop down box., (Fig 15), Fig 15, , Fig 36, , Office Backstage, The Office Backstage is a new concept, it is the enhanced, form of the plain old office button and provides a much, user-friendly menu. It helps users to manage documents,, presentations, or spreadsheets at a greater level. (Fig 13), , Interesting feature, right? Read more about it here., , Copa 11829036, , Copa 11829034, , Fig Fig, 3413, , Improved Spell Checks, Word 2010 has added some new features to its spell, checker, now it will detect the mistake and suggest, changing the sentence., , Fig, Fig 16, , New Art Effects in WordArt, , 37, , Just like other features, WordArt has been updated with, new colorful art effects. Select the text, then click Word, Art and a list of all the available options will be displayed., (Fig 14), , 120, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , Copa 11829037, , Fig 35, , Copa 11829035, , Fig 14
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Shortcut keys in Word 2010, Objective : at the end of the lesson you shall be able to, •, , Learn the shortcut keys in MS Word., CTRL+SHIFT+A, , converts the selected text to capital letters or vice versa, , CTRL+SHIFT+F, , Displays the Font dialog box., , CTRL+SHIFT+G, , Displays the Word Count dialog box., , CTRL+SHIFT+S, , Displays the Apply Styles task pane., , ALT+R, , Displays the Review tab, , ALT+CTRL+1, , Apply Heading 1, Similarly ALT + CTRL + 2 will apply heading 2, , CTRL+SHIFT+L, , Applies Bullets, , CTRL+SHIFT+F5, , Bookmark, , CTRL + B, , Bold Text, , CTRL + I, , Italic Text, , CTRL + U, , Underline Text, , CTRL+PAGE DOWN Browse Next, CTRL+E, , Navigate to the center Paragraph, , CTRL+SHIFT+ENTER, , Column Break, , CTRL+SHIFT+C, , Copy Format, , ALT+SHIFT+F7, , Dictionary, , ALT+CTRL+S, , Splits the Document, , CTRL+SHIFT+D, , Double Underline, , CTRL+END, , End of Document, , END, , End of line, , CTRL+SHIFT+P, , Font size select, , SHIFT+F5 or ALT+CTRL+Z, , Go Back to previous state, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 121
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.38, , Typing practice using open source typing tutor tools, Objectives : At the end of this lesson you shall be able to, • understand about typing software, • typing Tutor tools., You will be able to learn touch typing quickly and efficiently, with the program's intelligent practice lessons, useful, support functions and an extensive progress tracker. You, can also play a typing game and expand the program with, open lessons or make your own to meet your specific, needs., , The Typing Tutor Advantage, , Full courses for Beginner, Advanced and Expert typists, , •, , •, , Introduction course. First time using keyboard. The, course covers all characters typed on your keyboard., , •, , Beginner course. This course helps to learn the position, of keys on the keyboard. After completing this course,, you will know which finger to use to hit each key without, looking at the keyboard. The course also covers uppercase letters, special symbols, and the numeric pad., , •, , •, , Create classes to group your students, and Import, your entire student roster using our simple Student, Import tool., , •, , Statistical Graphs & Charts, Both students and teachers have access to detailed, graphs and statistics to track progress., , •, , Complete Course - Novice to Professional, Beginner, Intermediate, Advanced, and Specialty, Lessons to help typists of all levels., , •, , Fun Interactive Typing Games, Students can take a break from the exercises to, practice with several educational typing games., , Progress Tracking, The statistics reflect your typing speed, accuracy and, time-out, complete with a summary at the end of each, lesson., , •, , •, , and it suggests your next step: Go to the next lesson, or Try again comparing the results with Course goals., , •, , •, , You can evaluate your own performance or students at, any time by simply looking at charts., , •, , overall lesson rate, typing speed( WPM, CPM, KPM,, WPS, CPS, KPS ), accuracy and time-out are enabled, in the both: table and chart presentation, , •, , also, for each lesson, statistics by each character and, keystroke in the column charts, , •, , Reporting, Access and export detailed reporting data. Reports, and graphs exist for all levels of data., , Advanced course, helps to improve your typing speed, by memorizing frequently used syllables and words., Expert course helps you to perfect the skills acquired, by typing an actual text., , Easy to Get Started, , Typing Test, Students can repeat the typing test to track their, progress over time., Helpful Typing Hints & Tips, Tips and helpful technique information is constantly, provided to reinforce proper typing techniques., , •, , On-Screen Keyboard & Hand Diagram, Key position and proper finger placement is always, displayed to keep beginners from looking at their, hands., , Copyright @ NIMI Not to be Republished, , 123
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IT & ITES, Related Theory for Exercise 1.7.39 to 1.7.41, COPA - Spread Sheet Application, Introduction to MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Features & Functions of Microsoft Excel, Whether for work or home use, an Excel spreadsheet is, the best tool in Microsoft Office for organizing data and, making lists. Although Word documents can include, tables and columns, Excel makes laying out information, for easier. Excel also has a range of functions for designing, formulas that automate calculations. Although Excel looks, intimidating at first, the program's layout is similar to other, Office applications., Cells and Worksheets, The main portion of Excel's window consists of a, spreadsheet -- or worksheet of cells. Just as with a paper, spreadsheet, each cell can contain any numbers or any, text -- unlike working with an Access database, Excel, allows to simply click on any cell and fill it however best, fits the project., In some cases, such as to track spending, if want to use, an organized series of rows and columns. Other times,, such as building a list of team members, cell order and, positioning won't play a major role. One advantage to, Excel is how simple it makes reorganizing data: select a, cell and drag its border to move it to a new spot on the, sheet., Excel Workbooks, Every Excel file, called a workbook, contains one or more, worksheets. To switch between sheets in a workbook,, use the tabs in the lower left corner of the window. Since, Excel 2010, most workbooks use the file extension XLSX,, , 124, , whereas older versions used XLS files. New copies of Excel, can read these old files, but to open a new workbook in an, old edition, the old PC needs the Office compatibility pack., Formulas and Functions, In addition to containing plain text and numbers, cells, can contain formulas, which always start with an equals, sign. With a formula, Excel displays the result of an, equation in a cell, but automatically keeps that result, up-to-date as you change its components. A basic formula, can take the place of a calculator: write "=2+4" and Excel, displays "6." Formulas also work with data in other cells:, "=A1+B1" adds the values of cells A1 and B1., For procedures other than direct arithmetic, use functions, to perform various operations on data. Functions' abilities, range from simple math, such as "AVERAGE" to average, a range of cells, to modifying text, such as "LOWER" to, convert a line to lower case., The two terms are often confused, but remember that, each cell can contain only one formula, but each formula, can use multiple functions, such as "=AVERAGE(A1,, B1)+SUM(A2, B2)" to add the sum of two cells to the, average of two other cells., The following basic window appears when you start the, excel application. Let us, now understand the various important parts of this window, as shown in fig-1., Ribbon Tabs, , Copyright @ NIMI Not to be Republished
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Copa 1203901, , Fig 1, , As with the rest of Office since 2007, Microsoft has, replaced Excel's menus with ribbon tabs as shown in, fig-2. The tab as visual menus that remain open each, tab contains a set of related features with explanatory, icons. For example, the Home tab contains the most, common options, such as font and text color, while the, Insert tab offers ways to insert tables, text boxes and, charts. One tab, File, behaves differently. File still, contains basic tasks including "New," "Open" and "Save,", but displays these tasks in a full-screen area with extra, options, called the backstage view. For example, the, "New" button in the backstage view offers a searchable, selection of templates for new workbooks., , Fig 2, , Copa 1203902, , Ribbon contains commands organized in three, , components:, Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert, Page, Layout is the examples of ribbon tabs., Groups: They organize related commands; each group, name appears below the group on the Ribbon. For, example, group of commands related to fonts or group, of commands related to alignment etc., ?Home: Use this tab when creating, formatting, and, editing a spreadsheet., This tab is arranged into the Clipboard, Font, Alignment,, Number, Styles, Cells, and Editing groups., , Insert: Use this when adding particular elements (including, graphics, PivotTables, charts, hyperlinks, and headers and, footers) to a spreadsheet. This tab is arranged into the, Tables, Illustrations, Sparkline, Filter, Charts, Links, and, Text groups., Page Layout: Use this tab when preparing a spreadsheet, for printing or reordering graphics on the sheet. This tab, is arranged into the Themes, Page Setup, Scale to Fit,, Sheet Options, and Arrange groups., Formulas: Use this tab when adding formulas and, functions to a spreadsheet or checking a worksheet for, formula errors. This tab is arranged into the Function, Library, Defined Names, Formula Auditing, and, Calculation groups. Note that this tab also contains a, Solutions group when activate certain add-in programs,, Data: Use this tab when importing, querying, outlining,, and subtotaling the data placed into a worksheet's data, list. This tab is arranged into the Get External Data,, Connections, Sort & Filter, Data Tools, and Outline, groups., Review: Use this tab when proofing, protecting, and, marking up a spreadsheet for review by others. This tab, is arranged into the Proofing, Language, Comments, and, Changes groups. Note that this tab also contains an Ink, group with a sole Start Inking button if you're running, Office 2010 on a Tablet PC or on a computer equipped, with some sort of electronic input tablet., View: Use this tab when changing the display of the, Worksheet area and the data it contains. This tab is, arranged into the Workbook Views, Show, Zoom,, Window, and Macros groups., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 125
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Title Bar, , Status Bar, , This lies in the middle and at the top of the window. Title, bar shows the program and the sheet titles., , This displays the sheet information as well as the insertion, point location. From left to right, this bar can contain the, total number of pages and words in the document,, language etc., , Help, The Help Icon can be used to get excel related help, anytime you like. Thisprovides nice tutorial on various, subjects related to excel., Zoom Control, Zoom control lets to zoom in for a closer look at your, text. The zoom control consists of a slider that user can, slide left or right to zoom in or out. The + buttons can be, clicked to increase or decrease the zoom factor., View Buttons, The group of three buttons located to the left of the Zoom, control, near the, bottom of the screen, lets to switch among excel's various, sheet views., Normal Layout view: This displays the page in normal, view., , user can configure the status bar by right-clicking, anywhere on it and byselecting or deselecting options, from the provided list, File Tab, The File tab replaces the Office button from Excel 2010., user can click it to check the Backstage view, where, user come to open or save files, create new sheets, print, a sheet, and do other file-related operations., Quick Access Toolbar, TheFile tab and its purpose is to provide a convenient, resting place for the Excel's most frequently used, commands. And customize this toolbar based on the, comfort., Dialog Box Launcher(Fig-3), , Page Layout view: This displays pages exactly as they, will appear when printed. This gives a full screen look of, the document., , This appears as a very small arrow in the lower-right, corner of many groups on the Ribbon. Clicking this button, opens a dialog box or task pane that providesmore, options about the group., , Page Break view: This shows a preview of where pages, will break when printed., , If already have an opened sheet then it will display a, window showing the, , Sheet Area, , details about the opened sheet as shown fig-4. Backstage, view shows threecolumns when select most of the, available options in the first column., , The area where to enter data. The flashing vertical bar, is called the insertion point and it represents the location, where text will appear when type., Row Bar, , Fig 3, , Rows are numbered from 1 onwards and keeps on, increasing as to keepentering data. Maximum limit is, 1,048,576 rows., Columns are numbered from A onwards and keeps on, increasing as to keep, entering data. After Z, it will start the series of AA, AB, and so on. Maximum limit is 16,384 columns., First column of the backstage view will have the following options as shown in, Table-1:, Option, , Description, , Save, , If an existing sheet is opened, it would be saved as is,otherwise it will display a dialogue, box asking for thesheet name., , Save As, , A dialogue box will be displayed asking for sheet nameand sheet type. By default, it will, save in sheet 2010 format with extension .xlsx., , Open, , This option is used to open an existing excel sheet., , Close, , This option is used to close an opened sheet., , Info, , This option displays the information about the openedsheet., , 126, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , Copa 1203903, , Column Bar
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Option, , Description, , Recent, , This option lists down all the recently opened sheets., , New, , This option is used to open a new sheet., , Print, , This option is used to print an opened sheet., , Save & Send, , This option saves an opened sheet and displays options to send the sheet using email etc., , Help, , You can use this option to get the required help about excel 2010., , Options, , Use this option to set various option related to excel 2010., , Exit, , Use this option to close the sheet and exit., , Sheet Information, When click Info option available in the first column, it, displays the following information in the second column, of the backstage view:, , Fig 5, , Compatibility Mode: If the sheet is not a native excel, 2007/2010 sheet, a Convert button appears here,, enabling to easily update its format. Otherwise, this, category does not appear., Permissions: This option used to protect the excel sheet., And can set a password so that nobody can open the, sheet, or lock the sheet so that nobody can edit the sheet., , Versions: If the sheet has been saved several times,, and may be able to access previous versions of it from, this section., Sheet Properties, When click Info option available in the first column, it, displays various properties in the third column of the, backstage view. These properties include sheet size, title,, tags, categories etc., user can also edit various properties. Just try to click on, the property value and if property is editable, then it will, display a text box where can add the text like title, tags,, comments, Author., , Copa 1203905, , Prepare for Sharing: This section highlights important, information should know about the sheet before send it, to others, such as a record of the edits the made as, developed the sheet., , Sheet area is the place of type the text. The flashing vertical, bar iscalled the insertion point and it represents the location, where text will appearwhen type. When click on a box, then the box is highlighted. When double click the box,, the flashing vertical bar appears and can start entering the, data., So, just keep the mouse cursor at the text insertion point, and start typing whatever text would like to type. We, have typed only two words "HelloExcel" as shown fig-6., The text appears to the left of the insertion point., Fig 6, , Entering values, , Copa 1203906, , A new sheet is displayed by default when open an excel, sheet as shown in the fig-5 screen shot., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 127
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There are following three important points, which would help while typing:, • Press Tab to go to next column., •, , Press Enter to go to next row., , •, , Press Alt + Enter to enter a new line in the same, column., , Move Around in Excel 2010, Excel provides a number of ways to move around a sheet, using the mouse and the keyboard., , First of all, let us create some sample text before we, proceed. Open a new excel sheet and type any data. A, sample data table as shown table-2 and fig-7., , OrderDate, , Region, , Rep, , Item, , Units, , Unit Cost, , Total, , 1/6/2010, , East, , Jones, , Pencil, , 95, , 1.99, , 189.05, , 1/23/2010, , Central, , Kivell, , Binder, , 50, , 19.99, , 999.5, , 2/9/2010, , Central, , Jardine, , Pencil, , 36, , 4.99, , 179.64, , 2/26/2010, , Central, , Gill, , Pen, , 27, , 19.99, , 539.73, , 3/15/2010, , West, , Sorvino, , Pencil, , 56, , 2.99, , 167.44, , 4/1/2010, , East, , Jones, , Binder, , 60, , 4.99, , 299.4, , 4/18/2010, , Central, , Andrews, , Pencil, , 75, , 1.99, , 149.25, , 5/5/2010, , Central, , Jardine, , Pencil, , 90, , 4.99, , 449.1, , 5/22/2010, , West, , Thompson, , Pencil, , 32, , 1.99, , 63.68, , 6/8/2010, , East, , Jones, , Binder, , 60, , 8.99, , 539.4, , 6/25/2010, , Central, , Morgan, , Pencil, , 90, , 4.99, , 449.1, , 7/12/2010, , East, , Howard, , Binder, , 29, , 1.99, , 57.71, , 7/29/2010, , East, , Parent, , Binder, , 81, , 19.99, , 1,619.19, , 8/15/2010, , East, , Jones, , Pencil, , 35, , 4.99, , 174.65, , Moving with Mouse, , Table-2, , Mouse can easily move the insertion point by clicking in, the text anywhere on the screen. Sometime if the sheet, is big then user cannot see a place need to move. In, such situations, to use the scroll bars, as shown fig-8, screen shot., , Copa 1203907, , Fig 7, , 128, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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User can move box by box or sheet by sheet. Now click, in any box containing data in the sheet. It would have to, hold down the Ctrl key while pressing an arrow key, which, moves the insertion point as described here -, , Fig 8, , Copa 1203908, , Key Combination, , Where the Insertion Point, Moves, , Ctrl +, , Î, , To the last box containing data, of the current row., , Ctrl +, , Í, , To the first box containing data, of the current row., , Ctrl +, , Ï, , To the first box containing data, of the current column., , Ctrl +, , Ð, , To the last box containing data, of the current column., , Ctrl + Page Up, , To the sheet in the left of the, current sheet., , user can scroll the sheet by rolling mouse wheel, which, is equivalent to clicking the up-arrow or down-arrow, buttons in the scroll bar., , Ctrl + Page Down, , To the sheet in the right of the, current sheet., , Ctrl + Home, , To the beginning of the sheet., , Moving with Scroll Bars, , Ctrl + End, , To the end of the sheet., , As shown in the above screen capture, there are two, scroll bars: one for moving vertically within the sheet,, and one for moving horizontally. Using the vertical scroll, bar, user may ?, •, , Move upward by one line by clicking the upwardpointing scroll arrow., , •, , Move downward by one line by clicking the downwardpointing scroll arrow., , •, , Move one next page, using next page button, (footnote)., , •, , Move one previous page, using previous page button, (footnote)., , •, , Use Browse Object button to move through the sheet,, going from one chosen object to the next., , Moving with Go To Command, Press F5 key to use Go To command as shown in fig-9,, which will display a dialogue box contains various options, to reach to a particular box., Normally, we use row and column number, for example, K5 and finally press Go To button., , Fig 9, , Moving with Keyboard, , Keystroke, , Where the Insertion Point Moves, , Î, , Forward one box, , Í, , Back one box, , Ï, , Up one box, , Ð, , Down one box, , PageUp, , To the previous screen, , Copa 1203909, , The following keyboard commands, used for moving, around your sheet, also move the insertion point -, , PageDown To the next screen, Home, , To the beginning of the current screen, , End, , To the end of the current screen, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 129
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Conditional Formatting, , •, , MS Excel 2010 Conditional Formatting feature enables, to format a range of values so that the values outside, certain limits, are automatically formatted., Choose Home Tab " Style group " Conditional Formatting, dropdown., Various Conditional Formatting Options, •, , Top/Bottom Rules: It opens a continuation menu, with various options for defining the formatting rules, that highlight the top and bottom values, percentages,, and above and below average values in the cell, selection., , Suppose want to highlight the top 10% rows user can do, this with these Top/Bottom rules as shown in fig-12., , Fig 12, , Highlight Cells Rules ? It opens a continuation menu, with various options for defining the formatting rules, that highlight the cells in the cell selection that contain, certain values, text, or dates, or that have values, greater or less than a particular value, or that fall, within a certain ranges of values., , Copa 12039012, , Suppose to find cell with Amount 0 and Mark them as, red. Choose Range of cell " Home Tab " Conditional, Formatting DropDown " Highlight Cell Rules " Equal To as, on fig-10., , Fig 10, , Copa 12039010, , •, , Data Bars(fig-13): It opens a palette with different, color data bars that can apply to the cell selection to, indicate their values relative to each other by clicking, the data bar thumbnail., , With this conditional Formatting data Bars will appear in, each cell., , Fig 13, , After Clicking ok, the cells with value zero are marked as, red as shown in fig-11., , Copa 12039013, , Fig 11, , •, , Color Scales (Fig-14): It opens a palette with different, three- and two-colored scales that can apply to the, cell selection to indicate their values relative to each, other by clicking the color scale thumbnail., , Copa 12039011, , See the below screenshot with Color Scales, conditional, formatting applied., , 130, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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Linking Excel Worksheet Data Overview, , Fig 14, , In Excel, a link is a formula that dynamically pulls in, data from a cell in another worksheet. The worksheet, can be in the same workbook or a different workbook., , Copa 12039014, , The destination worksheet is the worksheet that contains, the link formula. The worksheet containing the data that, will be brought in is called the source worksheet., , • Icon Sets (Fig-15)? It opens a palette with different, sets of icons that can apply to the cell selection to indicate, their values relative to each other by clicking the icon, set., See the below screenshot with Icon Sets conditional, formatting applied., , Fig 15, , Any time the cell value in the source worksheet changes,, the cell containing the link formula will be updated as, well the next time the spreadsheet containing the link, formula is opened. This is just one of many reasons the, Excel software program is so powerful., Need for Linking Spreadsheet Data, The ability to create links often eliminates the need to, have identical data entered and updated in multiple, sheets. This saves time, reduces errors, and improves, data integrity. For example, a company's prices can be, stored in a 'Master Price List' worksheet, and others, needing pricing data can link to that worksheet., Consider a Sales Manager who has a detailed, spreadsheet for each salesperson, but would like a, summary sheet to compare salespersons' performance, and create grand totals. The summary sheet (destination), would bring in data from all the salespersons' sheets, (source)., Create the Worksheet Link, Before creating the link, format the cell, containing the link formula in the destination, worksheet to equal the format of the source data., For example, if the data from the source spreadsheet is, currency with 2 decimal points, then first format the target, cell for currency with 2 decimal places., , • New Rule: It opens the New Formatting Rule dialog, box, where define a custom conditional formatting rule, to apply to the cell selection., • Clear Rules: It opens a continuation menu, where, can remove the conditional formatting rules for the cell, selection by clicking the Selected Cells option, for the, entire worksheet by clicking the Entire Sheet option, or, for just the current data table by clicking the This Table, option., • Manage Rules: It opens the Conditional Formatting, Rules Manager dialog box, edit and delete particular rules, as well as adjust their rule precedence by moving them, up or down in the Rules list box., Link Excel Spreadsheet Data, Microsoft Excel provides the ability for cells in one, worksheet to be linked to cells in one or more other, worksheets. This is a great productivity tool and can, reduce the need for additional worksheets!, , METHOD ONE, 1. In the source worksheet, select the cell need to link, to and click the Copy button on the Home tab. Or, press Ctrl+C, or right-click and select Copy., 2. Switch to the destination spreadsheet and click the, cell want to link. Then, depending on the version of, Excel:, •, , Excel 2007, 2010, and 2013: On the Home tab, click, the down arrow below Paste and click Paste Link. In, newer versions also right-click and select the Paste, Link from the Paste menu., , •, , Excel 2003 and older versions: On the Edit menu,, click Paste Special, and then click Paste Link., , 3. Return to the source worksheet and press ESC to, remove the animated border around the cell., METHOD TWO, This is a fast method that works in a different order than, Method One., , 1. In the destination worksheet cell that will contain the, link formula, enter an equal sign (=)., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, 131, , Copyright @ NIMI Not to be Republished
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2. In the source worksheet, click in the cell that contains, the data and press the Enter key., , Fig 16, , Link Formula Example(Fig-16), In the example below, using Method One, we click in cell, B6 in the source worksheet and click Copy. Then, on the, destination worksheet, we click in cell B3, and paste the, link. The value ($3,500) automatically displays., , Copa 12039016, , Follow the same steps to link the data from the Denver, and Seattle worksheets to the Store Totals worksheet., And first formatted the cells to display the data as Currency., (Fig 16), , 132, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.7.42 - 1.7.46, COPA - Spread Sheet Application, Functions and formulas in MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Formulas in MS Excel, formula, worksheet will be just simple tabular, representation of data. A formula consists of special code,, which is entered into a cell. It performs some calculations, and returns a result, which is displayed in the cell., Formulas use a variety of operators and worksheet, functions to work with values and text. The values and, text used in formulas can be located in other cells, which, makes changing data easy and gives worksheets their, dynamic nature. For example, it can quickly change the, data in a worksheet and formulas works., Elements of Formulas, A formula can consist of any of these elements ?, •, , Creating Formula, For creating a formula need to type in the Formula Bar., Formula begins with '=' sign. When building formulas, manually, and can either type in the cell addresses or, can point to them in the worksheet. Using the Pointing, method to supply the cell addresses for formulas is often, easier and more powerful method of formula building., When using built-in functions, to click the cell or drag, through the cell range that want to use when defining, the function's arguments in the Function Arguments, dialog box as shown in Fig 1., Fig Fig, 17 1, , Mathematical operators, such as +(for addition), and *(for multiplication), , Example •, , Copa 12039017, , =A1+A2 Adds the values in cells A1 and A2., Values or text, , Example =200*0.5 Multiplies 200 times 0.5. This formula uses only, values, and it always returns the same result as 100., •, , Cell references (including named cells and, ranges), , Example =A1=C12 Compares cell A1 with cell C12. If the cells, are identical, the formula returns TRUE; otherwise, it, returns FALSE., •, , Worksheet functions (such as SUMor AVERAGE), , Example =SUM(A1:A12) Adds the values in the range A1:A12., , As soon as complete a formula entry, Excel calculates, the result, which is then displayed inside the cell within, the worksheet (the contents of the formula, however,, continue to be visible on the Formula bar anytime the, cell is active). If you make an error in the formula that, prevents Excel from being able to calculate the formula, at all, Excel displays an Alert dialog box suggesting how, to fix the problem., Functions in Formula, Many formulas are create use available worksheet, functions. These functions enable to greatly enhance the, power of the formulas and perform calculations that are, difficult if use only the operators. For example, and can, use the LOG or SIN function to calculate the Logarithm, or Sin ratio. And cannot do this complicated calculation, by using the mathematical operators alone., , Copyright @ NIMI Not to be Republished, , 133
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Using Functions, , Function Arguments, , When type = sign and then type any alphabet the, searched functions will showfig 2., , In the above examples, notice that all the functions used, parentheses. The information inside the parentheses is, the list of arguments., , Fig 2, Fig 18, , Copa 12039018, , Functions vary in how they use arguments. Depending, on what it has to do, a function may use., , Suppose need to determine the largest value in a range., A formula can't tell the answer without using a function., We will use formula that uses the MAX function to return, the largest value in the range B3:B8 as, =MAX(A1:D100)as shown in fig 3., , FigFig, 193, , •, , No arguments - Examples ? Now(), Date(), etc., , •, , One argument - UPPER(), LOWER(), etc., , •, , A fixed number of arguments - IF(), MAX(), MIN(),, AVERGAGE(), etc., , •, , Infinite number of arguments, , •, , Optional arguments, , Built In Functions, MS Excel has many built in functions, which we can use, in our formula. To see all the functions by category,, choose Formulas Tab " Insert Function as shown in fig-5., Then Insert function Dialog appears from which we can, choose the function., , Another example of functions. Suppose to find if the cell, of month is greater than 1900 then we can give Bonus to, Sales representative. The we can achieve it with writing, formula with IF functions as =IF(B9>1900,"Yes","No"), as shown in fig 4., , Copa 12039021, , Copa 12039019, , Fig 5, Fig 21, , Functions by Categories, Let us see some of the built in functions in MS Excel., Text Functions, LOWER: Converts all characters in a supplied text string, to lower case, , FigFig, 204, , UPPER : Converts all characters in a supplied text string, to upper case, TRIM : Removes duplicate spaces, and spaces at the, start and end of a text string, CONCATENATE : Joins together two or more text, strings., , Copa 12039020, , Fig 4, , 134, , LEFT : Returns a specified number of characters from, the start of a supplied text string., MID : Returns a specified number of characters from, the middle of a supplied text string, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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RIGHT : Returns a specified number of characters from, the end of a supplied text string., LEN: Returns the length of a supplied text string, FIND: Returns the position of a supplied character or text, string from within a supplied text string (case-sensitive)., Date & Time, DATE: Returns a date, from a user-supplied year, month, and day., TIME: Returns a time, from a user-supplied hour, minute, and second., DATEVALUE: Converts a text string showing a date, to, an integer that represents the date in Excel's date-time, code., , two supplied numbers., Filters in MS Excel, Filtering data in MS Excel refers to displaying only the, rows that meet certain conditions. (The other rows gets, hidden.), Using the store data, if user interested in seeing data, where Shoe Size is 36, then set filter to do this. Follow, the below mentioned steps to do this., •, , Place a cursor on the Header Row., , •, , Choose Data Tab ¾ Filter to set filter as shown in, fig 6., , Fig 22Fig 6, , TIMEVALUE: Converts a text string showing a time, to, a decimal that represents the time in Excel., NOW: Returns the current date & time., TODAY: Returns today's date., Statistical, , Copa 12039022, , MAX: Returns the largest value from a list of supplied, numbers., MIN: Returns the smallest value from a list of supplied, numbers., AVERAGE: Returns the Average of a list of supplied, numbers., COUNT: Returns the number of numerical values in a, supplied set of cells or values., COUNTIF: Returns the number of cells (of a supplied, range), that satisfies a given criteria., SUM: Returns the sum of a supplied list of numbers, , •, , Click the drop-down arrow in the Area Row Header and, remove the check mark from Select All, which unselects, everything., , •, , Then select the check mark for Size 36 which will filter, the data and displays data of Shoe Size 36 as shown, in fig-23., , •, , Some of the row numbers are missing; these rows, contain the filtered (hidden) data., , •, , There is drop-down arrow in the Area column now shows, a different graphic - an icon that indicates the column, is filtered. (Fig 7), , Logical, AND: Tests a number of user-defined conditions and, returns TRUE if ALL of the conditions evaluate to TRUE,, or FALSE otherwise, OR: Tests a number of user-defined conditions and, returns TRUE if ANY of the conditions evaluate to TRUE,, or FALSE otherwise., NOT: Returns a logical value that is the opposite of a, user supplied logical value or expression i.e. returns, FALSE if the supplied argument is TRUE and returns, TRUE if the supplied argument is FAL, , Fig 7, Fig 23, , Math & Trig, , SIGN: Returns the sign (+1, -1 or 0) of a supplied number., SQRT: Returns the positive square root of a given, number., MOD: Returns the remainder from a division between, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , Copa 12039023, , ABS: Returns the absolute value (i.e. the modulus) of a, supplied number., , 135
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Using Multiple Filters(fig-24), , 10, FigFig26, , Filtering of records by multiple conditions i.e. by multiple, column values. Suppose after size 36 is filtered,need to, have the filter where color is equal to Coffee. After setting, filter for Shoe Size, choose Color column and then set, filter for color. (Fig 8), , Copa 12039026, , Copa 12039024, , Fig 8, Fig 24, , -, , Values - alphabetically or numerically., , -, , Cell Color - Based on Color of Cell., , Sorting in MS Excel, , -, , Font Color - Based on Font color., , Sorting data in MS Excel rearranges the rows based on, the contents of a particular column. sort a table to put, names in alphabetical order Or sort data by Amount from, smallest to largest or largest to smallest., , -, , Cell Icon - Based on Cell Icon., , •, , Clicking Ok will sort the data as on fig 11., , To Sort the data follow the steps mentioned below., •, , Fig Fig, 27 11, , Select the Column to sort data as on fig 9., , Choose Data Tab " Sort Below dialog appears., , •, , If the user sort data based on a selected column,, Choose Continue with the selection or if the data, sorting based on other columns, choose Expand, Selection., , •, , Sort the data based on the below Conditions as on, fig 10., , Sorting option is also available from the Home Tab. Choose, Home Tab " Sort & Filter. You can see the same dialog to, sort records as on fig 12., , Fig 28, , Fig 12, , Copa 12039028, , •, , Copa 12039027, , 12039025, , 9, FigFig25, , 136, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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Ranges in MS Excel:, A cell is a single element in a worksheet that can hold a, value, some text, or a formula. A cell is identified by its, address, which consists of its column letter and row, number. For example, cell B1 is the cell in the second, column and the first row., , to return the navigation keys to normal movement., •, , Type the cell or range address into the Name box and, press Enter. Excel selects the cell or range that, specified. (Fig 13), , Fig 13, Fig 29, , A group of cells is called a range. You designate a range, address by specifying its upper-left cell address and its, lower-right cell address, separated by a colon., •, , C24, , - A range that consists of a single cell., , •, , A1:B1, , - Two cells that occupy one row and two, columns., , •, , A1:A100 - 100 cells in column A., , •, , A1:D4, , Copa 12039029, , Example of Ranges:, , - 16 cells (four rows by four columns)., , Selecting Ranges (Fig-29), Selecting a range in several ways ?, , Selecting Complete Rows and Columns (Fig-30), , •, , Press the left mouse button and drag, highlighting, the range. Then release the mouse button. If drag to, the end of the screen, the worksheet will scroll., , When user need to select an entire row or column.and, can select entire rows and columns in much the same, manner as select ranges:, , •, , Press the Shift key while uses the navigation keys to, select a range., , •, , Click the row or column border to select a single row, or column., , •, , Press F8 and then move the cell pointer with the, navigation keys to highlight the range. Press F8 again, , •, , To select multiple adjacent rows or columns, click a, row or column border and drag to highlight additional, rows or columns., , •, , To select multiple (nonadjacent) rows or columns,, press Ctrl while click the row or column borders., (Fig 14), , Copa 12039030, , Fig, Fig14, 30, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , 137
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IT & ITES, Related Theory for Exercise 1.7.47 & 1.7.48, COPA - Spread Sheet Application, Data validations and Table management in MsExcel 2010, Objectives : At the end of this lesson you shall be able to, • data Validation, • data Table with Example, • charts and its types, • pivot table and pivot chart, • page setup and printing worksheet, • excel shortcut keys, Data Validation, , •, , MS Excel data validation feature allows to set up certain, rules that dictate what can be entered into a cell. For, example, user want to limit data entry in a particular cell, to whole numbers between 0 and 10. If the user makes, an invalid entry, and display a custom message as shown, fig 1., , Decimal - The user must enter a number. For example,, you can specify that the entry must be greater than or, equal to 10 and less than or equal to 20., , •, , List - The user must choose from a list of entries you, provide. You will create drop-down list with this, validation. You have to give input ranges then those, values will appear in the drop-down., , •, , Date - The user must enter a date. You specify a valid, date range from choices in the Data drop-down list., For example, you can specify that the entered data, must be greater than or equal to January 1, 2013, and, less than or equal to December 31, 2013., , •, , Time - The user must enter a time. Specify a valid, time range from choices in the Data drop-down list., For example, user can specify that the entered data, must be later than 12:00 p.m., , •, , Text Length - The length of the data (number of, characters) is limited. specify a valid length by using, the Data drop-down list. For example, that the length, of the entered data be 1 (a single alphanumeric, character)., , •, , Custom - To use this option, must supply a logical, formula that determines the validity of the user's entry, (a logical formula returns either TRUE or FALSE)., , Copa 12039031, , FigFig311, , Validation Criteria, To specify the type of data allowable in a cell or range,, follow the steps below, which shows all the three tabs of, the Data Validation dialog box., •, , Select the cell or range., , •, , Choose Data " Data Tools " Data Validation. Excel, displays its Data Validation dialog box having 3 tabs, settings, Input Message and Error alert., , Input Message Tab(fig 2), Fig 2, , Fig 32, , Here user can set the type of validation. Choose an option, from the Allow drop-down list. The contents of the Data, Validation dialog box will change, displaying controls, based on your choice., •, , Any Value - Selecting this option removes any existing, data validation., , Whole Number - The user must enter a whole, number.For example, you can specify that the entry, must be a whole number greater than or equal to 50., 138, •, , Copyright @ NIMI Not to be Republished, , Copa 12039032, , Settings Tab
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User can set the input help message with this tab. Fill the, title and Input message of the Input message tab and the, input message will appear when the cell is selected., , Fig 5, Fig 34, , Error Alert Tab(fig 3), , User specify an error message with this tab. Fill the title, and error message. Select the style of the error as stop,, warning or Information as per user need., , Copa 12039034, , Copa 12039032, , FigFig, 323, , Now, for creation of data table select the range of data, table. Choose Data Tab " What-If analysis dropdown ", Data table. It will display dialogue asking for Input row and, Input Column. Give the Input row as Price cell (In this, case cell B3) and Input column as quantity cell (In this, case cell B4) as shown in fig 6., Fig 6, Fig 35, , Data Table with Example (Fig 4), Fig 4, , Copa 12039033, , Copa 12039035, , Fig 33, , Fig 36, , Fig 7, , Copa 12039036, , Here user have the Price and quantity of many values., Also, have the discount for that as third variable for, calculating the Net Price. And can keep the Net Price, value in the organized table format with the help of the, data table. The Price runs horizontally to the right while, quantity runs vertically down. We are using a formula to, calculate the Net Price as Price multiplied by Quantity, minus total discount (Quantity * Discount for each, quantity) as shown in fig 5., , Clicking OK will generate data table as shown in fig 7. It, will generate the table formula. And change the price, horizontally or quantity vertically to see the change in, the Net Price., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 139
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Charts, A chart is a visual representation of numeric values., Charts (also known as graphs) have been an integral, part of spreadsheets. Charts generated by early, spreadsheet products were quite crude, but thy have, improved significantly over the years. Excel provides, you with the tools to create a wide variety of highly, customizable charts. Displaying data in a well-conceived, chart can make your numbers more understandable., Because a chart presents a picture, charts are particularly, useful for summarizing a series of numbers and their, interrelationships., , •, , Stock: This chart type is most often used for stock, price data, but can also be used for scientific data, (for example, to indicate temperature changes)., , •, , Surface: A surface chart is useful to find the optimum, combinations between two sets of data. As in a, topographic map, colors and patterns indicate areas, that are in the same range of values., , •, , Doughnut: Like a pie chart, a doughnut chart shows, the relationship of parts to a whole; however, it can, contain more than one data series., , •, , Bubble: Data that is arranged in columns on a, worksheet, so that x values are listed in the first, column and corresponding y values and bubble size, values are listed in adjacent columns, can be plotted, in a bubble chart., , •, , Radar: A radar chart compares the aggregate values, of a number of data series., , Types of Charts, There are various chart types available in MS Excel as, shown in fig 8., Fig 8, , Fig 37, , Creating Chart, , •, , Column: Column chart shows data changes over a, period of time or illustrates comparisons among items., , •, , Bar: A bar chart illustrates comparisons among, individual items., , •, , Pie: A pie chart shows the size of items that make up, a data series, proportional to the sum of the items. It, always shows only one data series and is useful to, emphasize a significant element in the data., , •, , Line: A line chart shows trends in data at equal, intervals., , •, , Area: An area chart emphasizes the magnitude of, change over time., , •, , X Y Scatter: An xy (scatter) chart shows the, relationships among the numeric values in several, data series, or plots two groups of numbers as one, series of xy coordinates., , •, , Select the data for which you want to create the chart., , •, , Choose Insert Tab " Select the chart or click on the, Chart groupto see various chart types., , •, , Select the chart of the choice and click OK to generate, the chart as shown in fig 9., Fig 9, Fig 38, , Copa 12039038, , Copa 12039037, , To create charts for the data by below mentioned steps., , Editing Chart, You can edit the chart at any time after you have created, it., •, , 140, , select the different data for chart input with Right click, on chart " Select data. Selecting new data will, generate the chart as per the new data, as shown in, fig 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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This will generate the Pivot table pane as shown in fig-41., various options available in the Pivot table pane. And can, select fields for the generated pivot table. (Fig 13), , Fig 10, Fig 39, , •, , change the X axis of the chart by giving different inputs, to X-axis of chart., , •, , change the Y axis of chart by giving different inputs to, Y-axis of chart., , Pivot Tables, A pivot table is essentially a dynamic summary report, generated from a database. The database can reside in, a worksheet (in the form of a table) or in an external, data file. A pivot table can help transform endless rows, and columns of numbers into a meaningful presentation, of the data. Pivot tables are very powerful tool for, summarized analysis of the data., Pivot tables are available under Insert tab " PivotTable, dropdown " PivotTable., Pivot Table Example (Fig-40), Now, let us see Pivot table with the help of example., Suppose huge data of voters and need to see the, summarized data of voter Information per party, use the, Pivot table for it. Choose Insert tab " Pivot Table to insert, pivot table. MS Excel selects the data of the table. and, select the pivot table location as existing sheet or new, sheet. (Fig 11), , Copa 12039041, , Copa 12039039, , FigFig, 4112, , •, , Column labels: A field that has a column orientation, in the pivot table. Each item in the field occupies a, column., , •, , Report Filter: User can set the filter for the report as, year, and then data gets filtered as per the year., , •, , Row labels: A field that has a row orientation in the, pivot table. Each item in the field occupies a row., , •, , Values area: The cells in a pivot table that contain, the summary data. Excel offers several ways to, summarize the data (sum, average, count, and so, on)., , After giving input fields to the pivot table, it generates the, pivot table with the data as shown in fig 13., FigFig, 4213, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , Copa 12039042, , Copa 12039040, , Fig 40Fig 11, , 141
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Pivot Charts, , •, , A pivot chart is a graphical representation of a data, summary, displayed in a pivot table. A pivot chart is, always based on a pivot table. Although Excel lets to, create a pivot table and a pivot chart at the same time,, user can't create a pivot chart without a pivot table. All, Excel charting features are available in a pivot chart., , Press Ctrl+P and then click the Print button (or press, Enter)., , FigFig, 4516, , Pivot charts are available under Insert tab ¾ PivotTable, dropdown ¾ PivotChart., Pivot Chart Example, , Copa 12039045, , Suppose huge data of voters and need to see the, summarized view of the data of voter, Information per party in the form of charts, then use the, Pivot chart for it. Choose Insert tab ¾ Pivot Chart to, insert the pivot table. (Fig 14), , FigFig, 4314, Adjusting Common Page Setup Settings, , Copa 12039043, , User can adjust the print settings available in the Page, setup dialogue in different ways as discussed below. Page, setup options include Page orientation, Page Size, Page, Margins, etc., , MS Excel selects the data of the table. And select the, pivot chart location as an existing sheet or a new sheet., Pivot chart depends on automatically created pivot table, by the MS Excel. generate the pivot chart in the below, fig 15., , •, , The Print screen in Backstage View, displayed when, choose File " Print., , •, , The Page Layout tab of the Ribbon., , Choosing Your Printer(fig-46), To switch to a different printer, choose File ¾ Print and, use the drop-down control in the Printer section to select, any other installed printer. (Fig 17), Fig 17, , Fig 46, , Quick Print, If user want to print a copy of a worksheet with no layout, adjustment, use the Quick Print option. There are two, ways in which we can use this option., •, , Copa 12039046, , Copa 12039044, , Fig Fig, 4415, , Specifying What You Want to Print(Fig 18), Sometimes print only a part of the worksheet rather than, the entire active area. Choose File ¾ Print and use the, controls in the Settings section to specify what to print., •, , Active Sheets: Prints the active sheet or sheets that, you selected., , Choose File " Print (which displays the Print pane),, and then click the Print button as shown in fig 16., , 142, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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•, , Entire Workbook: Prints the entire workbook, including, chart sheets., , •, , Selection: Prints only the range that selected before, choosing File ¾ Print., , MS Excel Keyboard Short-cuts, MS Excel offers many keyboard short-cuts. Below is the list of all the major shortcut keys in Microsoft Excel., (Fig 18), , Copa 12039047, , FigFig, 4718, , •, , Ctrl + A, , -, , Selects all contents of the worksheet., , •, , Ctrl + B, , -, , Bold highlighted selection., , •, , Ctrl + I, , -, , Italicizes the highlighted selection., , •, , Ctrl + K, , -, , Inserts link., , •, , Ctrl + U, , -, , Underlines the highlighted selection., , •, , Ctrl + 1, , -, , Changes the format of selected cells., , •, , Ctrl + 5, , -, , Strikethrough the highlighted selection., , •, , Ctrl + P, , -, , Brings up the print dialog box to begin printing., , •, , Ctrl + Z, , -, , Undo last action., , •, , Ctrl + F3, , -, , Opens Excel Name Manager., , •, , Ctrl + F9, , -, , Minimizes the current window., , •, , Ctrl + F10, , -, , Maximize currently selected window., , •, , Ctrl + F6, , -, , Switches between open workbooks or windows., , •, , Ctrl + Page up, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Page down, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Tab, , -, , Moves between Two or more open Excel files., , •, , Alt + =, , -, , Creates a formula to sum all of the above cells, , •, , Ctrl + ', , -, , Inserts the value of the above cell into cell currently selected., , •, , Ctrl + Shift + !, , -, , Formats the number in comma format., , •, , Ctrl + Shift + $, , -, , Formats the number in currency format., , •, , Ctrl + Shift + #, , -, , Formats the number in date format., , •, , Ctrl + Shift + %, , -, , Formats the number in percentage format., , •, , Ctrl + Shift + ^, , -, , Formats the number in scientific format., , •, , Ctrl + Shift + @, , -, , Formats the number in time format., , •, , Ctrl + Arrow key, , -, , Moves to the next section of text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 143
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•, , Ctrl + Space, , -, , Selects the entire column., , •, , Shift + Space, , -, , Selects the entire row., , •, , Ctrl + -, , -, , Deletes the selected column or row., , •, , Ctrl + Shift + =, , -, , Inserts a new column or row., , •, , Ctrl + Home, , -, , Moves to cell A1., , •, , Ctrl + ~, , -, , Switches between showing Excel formulas or their values in cells., , •, , F2, , -, , Edits the selected cell., , •, , F3, , -, , After a name has been created F3 will paste names., , •, , F4, , -, , Repeat last action. For example, if you changed the color of text in another, cell pressing F4 will change the text in cell to the same color., , •, , F5, , -, , Goes to a specific cell. For example, C6., , •, , F7, , -, , Spell checks the selected text or document., , •, , F11, , -, , Creates chart from the selected data., , •, , Ctrl + Shift + ;, , -, , Enters the current time., , •, , Ctrl + ;, , -, , Enters the current date., , •, , Alt + Shift + F1, , -, , Inserts New Worksheet., , •, , Alt + Enter, , -, , While typing text in a cell pressing Alt + Enter will move to the next line, allowing for multiple lines of text in one cell., , •, , Shift + F3, , -, , Opens the Excel formula window., , •, , Shift + F5, , -, , Brings up the search box., , 144, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.8.49 - 1.8.57, COPA - Image Editing and Presentations, Image editing, presentations, Objectives : At the end of this lesson you shall be able to, • Introduction to Power Point and its advantages, • Creation of slide shows, • Fine tuning of presentations, Introduction, , Working with PowerPoint 2010, , PowerPoint is a presentation graphics software program, that is part of the Microsoft Office package. It uses a, graphical approach for the presentations in the form of, slide shows that accompany the oral delivery of the topic., This program is widely used in business and classrooms, and is an effective tool when used for training purposes., , Step 1: Click the Start button., , PowerPoint 2010 allowsto create presentations for printing or online viewing using a variety of tools. These include wizards to help with the content and look and feel, of the presentations to animation tools to create moving, images., , Copa 1214901, , PowerPoint is one of the simplest computer programs, to learn. It is the easiest program used worldwide for, presentations that creates professional looking presentations. It is easy to customize presentations with company logo and has design templates that come with the, programs. In addition to an on screen slide show,, PowerPoint has printing options that allow the presenter, to provide handouts and outlines for the audience as, well as notes pages for the speaker to refer to during the, presentation., , Fig 1, , Step 2: Click All Programs option from the menu., , Fig 2, , Presentation, , Copa 1214902, , A presentation is a collection of data and information, that is to be delivered to a specific audience. A, PowerPoint presentation is a collection of electronic, slides that can have text, pictures, graphics, tables, sound, and video. This collection can run automatically or can, be controlled by a presenter., Advantage and application of PowerPoint 2010, Professional looking presentations, , •, , Animated presentations shown on a monitor or overhead screen, , •, , Notes for the speaker, , •, , Handouts for the audience, , •, , Paper printouts of your slide, , •, , Overhead projector transparencies, , •, , Movies, , Step 3: Search for Microsoft Office from the sub menu, and click it., Fig 3, , Copa 1214903, , •, , Copyright @ NIMI Not to be Republished, , 145
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Step 4: Search for Microsoft PowerPoint 2010 from the, submenu and click it., , Fig 4, , File Tab, This tab opens the Backstage view which basically allows to manage the file and settings in PowerPoint. This, can save presentations, open existing ones and create, new presentations based on blank or predefined templates. The other file related operations can also be executed from this view., Ribbon, , This will launch the Microsoft PowerPoint 2010 application and the following is the presentation window., , Copa 1214905, , Fig 5, , Copa 1214907, , Copa 1214904, , Fig 7, , The ribbon contains three components:, •, , Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert,, Page Layout are examples of ribbon tabs., , •, , Groups: They organize related commands; each, group name appears below the group on the Ribbon., For example, a group of commands related to fonts, or a group of commands related to alignment, etc., , •, , Commands: Commands appear within each group, as mentioned above., , Title Bar, This is the top section of the window. It shows the name, of the file followed by the name of the program which in, this case is Microsoft PowerPoint., Slide Area, This is the area where the actual slide is created and, edited.Add, edit and delete text, images, shapes and, multimedia is supported in this section., , PowerPoint Screen, Fig 6, , Help, The Help Icon can be used to get PowerPoint related, help anytime. Clicking on the "?" opens the PowerPoint, Help window where there is a list of common topics to, browse from. Specific topics from the search bar at the, top can also be used for searching., Zoom Options, The zoom control zooms in for a closer look at the text., The zoom control consists of a slider that can slide left, or right to zoom in or out, - and + buttons to can be used, to increase or decrease the zoom factor. The maximum, zoom supported by PowerPoint is 400% and the 100%, is indicated by the mark in the middle., , Copa 1214906, , Slide Views, The group of four buttons located to the left of the Zoom, control, near the bottom of the screen, lets to switch, between PowerPoint views., •, , 146, , Normal Layout view: 1 This displays page in normal, view with the slide on the right and a list of thumbnails to the left. This view allowsuser to edit individual, slides and also rearrange them., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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•, , Slide Sorter view: This displays all the slides as a, matrix. This view only allows the user to rearrange, the slides but not edit the contents of each slide., , •, , Reading View: This view is like a slideshow with access to the Windows task bar in case the user need, to switch windows. However, like the slideshow user, cannot edit anything in this view., , •, , First Pane ? This is the commands pane which consists of all the commands that would typically found, in the file menu of older versions. it also has the, Options menu which edits the options on the program, like customizing the ribbon., , Various commands under the first pane are described in, the table below ?, S.No, , Notes Section, , 1, , This sections allows user to add notes for the presentation. These notes will not be displayed on the screen, during the presentation; these are just quick reference, for the presenter., , Command & Description, Save, This allows user to save a new file or an existing, file in standard format. If user is working on a pre, viously saved file this will save the new changes, in the same file format. If user is working on a, new file, this command would be similar to the, Save As command., , Quick Access Toolbar, The Quick Access Toolbar is located just under the ribbon. This toolbar offers a convenient place to group the, most commonly used commands in PowerPoint. User, can customize this toolbar to suit their needs., , 2, , Save As, Allows user to specify the file name and the file, type before saving the file., , Slide Tab, 3, , This section is available only in the Normal view. It displays all the slides in sequence. User can add, delete, and reorder slides from this section., , Open, Allows user to open new PowerPoint files., , 4, , Backstage View in Powerpoint 2010, , Close, Allows user to close an existing file., , In Office 2010, Microsoft replaced the traditional file, menu with the new Backstage view. This view not only, offers all the menu items under the file menu, but additional details which makes management of files a lot, easier., , 5, , Info, Displays the information about the current file., , 6, , Recent, Lists series of recently viewed or edited, PowerPoint files., , Accessing Backstage View, User can access the Backstage view simply by clicking, on the File tab. They can exit this view by clicking on, any tab (including the File tab again). 'Esc' button on, the keyboardcanalso be pressed for the same., , 7, , New, Allows user to create a new file using blank or, pre-defined templates., , Organization of Backstage View, , 8, , The backstage view has three sections or panes., , Print, Allows user to select the printer settings and print, the presentation., , Fig 8, , 9, , Save & Send, Allows user to share your presentation with larger, audience via emails, web, cloud services, etc., , 10, , Help, Provides access to PowerPoint Help., , 11, , Options, Allows user to set various options related to, PowerPoint program., , Copa 12149008, , 12, , Exit, Closes the presentation and exits the program., , •, , Second Pane ? This is the subcommands pane. This, will list all the commands related to the main command chosen in the first pane. For example, if user, selects Print in the first pane, user get to choose the, printer and adjust the print settings in the second pane., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 147
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•, , Third Pane ? This is the preview or file information page., Depending on the command and the subcommand user, select, this pane will either display the properties of, the file or give a preview of the file., , Creating Presentation using Powerpoint 2010, PowerPoint offers a host of tools that will aid the user in creating a presentation. These tools are organized logically, into various ribbons in PowerPoint. The table below describes the various commands that can be accessed from the, different menus., Menu Category, , Ribbon Commands, , Home, , Clipboard functions, manipulating slides, fonts, paragraph settings, drawing objects and, editing functions., , Insert, , Insert tables, pictures, images, shapes, charts, special texts, multimedia and symbols., , Design, , Slide setup, slide orientation, presentation themes and background., , Transitions, , Commands related to slide transitions., , Animations, , Commands related to animation within the individual slides., , Slide Show, , Commands related to slideshow set up and previews., , Review, , Proofing content, language selection, comments and comparing presentations., , View, , Commands related to presentation views, Master slides, color settings and window arrange, ments., , Besides these depending on the objects selected in the, slide, there are other menu tabs that get enabled., Add New Slides in Powerpoint 2010, The following are the steps that allows the user to insert, a new slide ., , Step 2: The new slide is inserted. The layout of this slide, can be changed to suit the design requirements., , Fig 10, , Step 1: Right-click in the Navigation Pane under any, existing slide and click on the New Slide option., , Copa 1214909, , Copa 12149010, , Fig 9, , 148, , Step 3: To change the slide layout, right-click on the, newly inserted slide and go to the Layout option where, user can choose from the existing layout styles available ., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Subtitle Box, , Fig 11, , This is found only in slides with the Title layout. This is, indicated by "Click to add subtitle", , Copa 12149011, , Copa 12149013, , Fig 13, , Same steps can be followed to insert a new slide in between existing slides or at the end on the slide list., When we insert a new slide, it inherits the layout of its, previous slide with one exception. If inserting a new, slide after the first slide (Title slide), the subsequent slide, will have the Title and Content layout., , Fig 12, , Content Box, This is found in most of the slides that have a placeholder for adding content. This is indicated by "Click to, add text". This box allows user to add text as well as, non-text content. To add text to such a box, click anywhere on the box, except on one of the content icons in, the center and start typing., , Copa 12149014, , Copa 12149012, , Fig 14, , Adding Text in Boxes in Powerpoint 2010, PowerPoint allows users to add text to the slide in a, well-defined manner to ensure the content is well distributed and easy to read. The procedure to add the text, in a PowerPoint slide is always the same - just click in, the text box and start typing. The text will follow the default formatting set for the text box, although this formatting can be changed later as required., The most common content blocks in PowerPoint are:, , Text Only Box, This is not a default content box available in PowerPoint,, but user can create it using Slide Master, if required., This is also indicated by "Click to add text". The only, difference between the Text Only Box and the Content, Box is that the former only supports text in the content, area., , Title Box, This is typically found on slides with the title layout and, in all the slides that have a title box in them. This box is, indicated by "Click to add title"., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 149
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Fig 18, , Copa 12149016, , Fig 16, , Adding New Text Boxes in Powerpoint 2010, , Copa 12149018, , Most of the standard layouts come with the text box option. As mentioned, text boxes will have "Click to add, text" as the default text. Here are the steps to add new, text boxes in slide., Step 1: Click on the Text Box icon in the Home ribbon, under the Drawingsection., , Copa 12149016, , Fig 16, , Step 4: Alternately, user can click and drag the cursor, without releasing the click to create a text box., , Fig 19, , Step 2 : User will get the insert text box cursor that looks, like an inverted cross., , Copa 12149019, , Fig 17, , The size of the text box can be adjusted by selecting, one of the edges marked by squares or corners marked, by circles., , Copa 12149017, , Slide Show in Powerpoint 2010, , Fig 20, Copa 12149020, , Step 3: Click to insert a text box. User can now start, typing directly into the text box., , Most PowerPoint presentations are created to be run as, a slideshow. Most of these features of Powerpoint 2010, are really to help user create a good slideshow without, having to go through the entire presentation over and, over again after every minor change. Features related, to running the slideshow are grouped under the Slideshow, ribbon., , 150, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Section, , Menu Item, , Description, , Start Slideshow, , From Beginning, , Starts slideshow from beginning, , From Current Slide, , Starts slideshow from the current slide, , Broadcast Slideshow, , Allows users to broadcast the slideshows, using Microsoft's PowerPoint Broadcast Service, , Custom Slideshow, , Builds a custom slideshow by picking the slides you, want to run, , Set Up Slideshow, , Helps set up the slideshow including browser/ full screen, display, show options with or without narration/ animation,, pen and laser color during the slideshow and the slides to, be presented during the show, , Hide Slide, , Helps mark/ unmark the slide as hidden, so it is skipped or, shown during the slideshow respectively, , Rehearse Timing, , Allows users to rehearse the timing on each slide and the, entire slideshow, , Record Slideshow, , Records the slideshow including narration and animation, , Slideshow Checkboxes, , Helps set or avoid the use of narrative audio and rehearsed, timings during the show. Display media controls in the, slideshow view, , Resolution, , Defines resolution in slideshow view, , Show Presentation on, , Picks the monitor to display the presentation one - in case, of multiple monitors, , Use Presenter View, , Run presentation in Presenter view rather than just slideshow, view, , Set Up, , Monitors, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 151
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IT & ITES, Related Theory for Exercise 1.9.58 - 1.9.61, COPA - Database Management Systems, Concepts of data and Databases, Objectives : At the end of this lesson you shall be able to, • explain database structure and control, • describe Ms access database utilities., Microsoft Access is a Database Management System, (DBMS) from Microsoft that combines the relational, Microsoft Jet Database Engine with a graphical user, interface and software-development tools. It is a member, of the Microsoft Office suite of applications, included in, the professional and higher editions., •, , Microsoft Access is just one part of Microsoft's overall, data management product strategy., , •, , It stores data in its own format based on the Access, Jet Database Engine., , •, , Like relational databases, Microsoft Access also, allows you to link related information easily. For, example, customer and order data. However, Access, 2013 also complements other database products, because it has several powerful connectivity features., , •, , It can also import or link directly to data stored in, other applications and databases., , •, , As its name implies, Access can work directly with, data from other sources, including many popular PC, database programs, with many SQL (Structured, Query Language) databases on the desktop, on, servers, on minicomputers, or on mainframes, and, with data stored on Internet or intranet web servers., , •, , Access can also understand and use a wide variety, of other data formats, including many other database, file structures., , •, , You can export data to and import data from word, processing files, spreadsheets, or database files, directly., , •, , Access can work with most popular databases that, support the Open Database Connectivity (ODBC), standard, including SQL Server, Oracle, and DB2., , •, , Software developers can use Microsoft Access to, develop application software., , •, , Report (optional): Information from the database is, organized in a nicepresentation that can be printed, in an Access Report., , Architecture, •, , Access calls anything that can have a name an object., Within an Access desktop database, the main objects, are tables, queries, forms, reports, macros, data, macros, and modules., , •, , If you have worked with other database systems on, desktop computers, you might have seen the term, database used to refer to only those files in which, you store data., , •, , But, in Access, a desktop database (.accdb) also, includes all the major objects related to the stored, data, including objects you define to automate the, use of your data., , RDBMS, In the computing system (web and business applications),, there are enormous data that comes out every day from, the web. A large section of these data is handled by, Relational database management systems (RDBMS)., The idea of relational model came with E.F.Codd's 1970, paper "A relational model of data for large shared data, banks" which made data modeling and application, programming much easier. Beyond the intended benefits,, the relational model is well-suited to client-server, programming and today it is predominant technology for, storing structured data in web and business applications., MS Access - RDBMS, Microsoft Access has the look and feel of other Microsoft, Office products as far as its layout and navigational, aspects are concerned, but MS Access is a database, and, more specifically, a relational database., •, , Microsoft Access stores information which is called a, database. To use MS Access, you will need to follow, these four steps:, , Before MS Access 2007, the file extension was *.mdb,, but in MS Access 2007 the extension has been, changed to *.accdb extension., , •, , Database Creation: Create your Microsoft Access, database and specify what kindof data you will be, storing., , Early versions of Access cannot read accdb, extensions but MS Access 2007 and later versions, can read and change earlier versions of Access., , •, , An Access desktop database (.accdb or .mdb) is a, fully functional RDBMS., , •, , It provides all the data definition, data manipulation,, and data control features that you need to manage, large volumes of data., , •, , •, , Data Input: After your database is created, the data, of every business day canbe entered into the Access, database., , •, , Query: This is a fancy term to basically describe the, process of retrievinginformation from the database., , 152, , Copyright @ NIMI Not to be Republished
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You can use an Access desktop database (.accdb or, .mdb) either as a standalone RDBMS on a single, workstation or in a shared client/server mode across a, network., , •, , A desktop database can also act as the data source, for data displayed on webpages on your company, intranet., , •, , When you build an application with an Access desktop, database, Access is the, , RDBMS., Data Definition, Let us now understand what Data Definition is:, •, , •, , •, , In document or a spreadsheet, you generally have, complete freedom to define the contents of the, document or each cell in the spreadsheet., In a document, you can include paragraphs of text, a, table, a chart, or multiple columns of data displayed, with multiple fonts., In spreadsheet, you can have text data at the top to, define a column header for printing or display, and, you might have various numeric formats within the, same column, depending on the function of the row., , •, , An RDBMS allows you to define the kind of data you, have and how the data should be stored., , •, , You can also usually define rules that the RDBMS, can use to ensure the integrity of your data., , •, , For example, a validation rule might ensure that the, user can't accidentally store alphabetic characters in, a field that should contain a number., , Data Manipulation, Working with data in RDBMS is very different from, working with data in a word processing or spreadsheet, program., •, , In a word processing document, you can include, tabular data and perform a limited set of functions on, the data in the document., , •, , You can also search for text strings in the original, document and, with ActiveX controls, include tables,, charts, or pictures from other applications., , •, , In a spreadsheet, some cells contain functions that, determine the result you want, and in other cells, you, enter the data that provides the source information, for the functions., , •, , An RDBMS provides you many ways to work with, your data. For example,, , •, , You can search a single table for information or, request a complex search across several related, tables., , •, , You can update a single field or many records with a, single command., , •, , You can write programs that use RDBMS commands, to fetch data that you want to display and allow the, user to update the data., , Access uses the powerful SQL database language to, process data in your tables. Using SQL, you can define, the set of information that you need to solve a particular, problem, including data from perhaps many tables., Data Control, Spreadsheets and word processing documents are great, for solving single-user problems, but they are difficult to, use when more than one person needs to share the data., •, , When you need to share your information with others,, RDBMS gives you the flexibility to allow multiple users, to read or update your data., , •, , An RDBMS that is designed to allow data sharing, also provides features to ensure that no two people, can change the same data at the same time., , •, , The best systems also allow you to group changes, (which is also known as transaction) so that either all, the changes or none of the changes appear in your, data., , •, , You might also want to be sure that no one else can, view any part of the order until you have entered all, of it., , •, , Because you can share your Access data with other, users, you might need to set some restrictions on, what various users are allowed to see or update., , Designing a Database, The first step in creating a database is to think about, why you need it-what is its purpose? Once you know the, answer, you can begin designing your own database., Ask yourself questions like What kinds of information, will it store? How will I have to break down this information, so it can be stored in my database? How will I use the, data once it's in there?, The bookstore scenario, The best way to learn about designing a database is to, jump right in to the process. Let's pretend we work for, the bookstore, and we need to build a database for the, store to use. Let's think about what we might need the, database to do for us., The following diagram shows that we have customers and, sell books via orders, both in the store and online., , Fig 1, , Copa 1225801, , •, , The store needs a way to keep track of these things., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 153
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Determine the purpose of the database, The first step of designing a database is to determine the, purpose of the database. What do we need it to do?, At Ready-2-Read, our customers will place orders for, books. At the very least, we will want our database to, track the books we sell, the customers we sell them to,, and the date of each of the orders., The database will also be able to tell us where our, customers live when we need to send them books or, coupons. Additionally, we can use it to track our sales or, to make a bestseller list to post in the store., Plan database tables, Once we've established its purpose, we can begin about, how to break up the information into the tables the, database will need to store data. Recall that a table is a, collection of records, and each record is broken up into, the smallest pieces of needed information, called fields., , Book the customer is ordering, and the Date the order is, placed., Creating a new database with Access, When you launch Access 2007/2010, you will see the, Getting Started window., In the left pane, the template categories-including the, featured local templates-are listed, as well as the, categories on Office Online. Templates are prebuilt, databases focused on a specific task that you can, download and use immediately., You will also see the New Blank Database option, which, allows you to build your own database from scratch., , Fig 2, , Customers, , -, , Orders, , -, , Books, , Plan table fields, Once you know what tables you need, the next step is, deciding what fields belong in each table. Remember, that fields are the smallest chunk of information in any, record., Let's look at our Ready-2-Read bookstore example again., There will be several fields in our Customers table. We'll, obviously want each customer's first name and last name., We'll also need an address if we need to send a customer, his order. Email will be necessary if we need to contact, the customer if there is an issue with the order., Customers, , Books, , Orders, , First Name, , Title, , Customer, , Last Name, , Author First, , Book, , Street, , Author Last, , Date, , City, , Price, , State, , Category, , When you choose the New Blank Database option at the, top of the window, you will be prompted to rename the, database from the default name, which is, Database1.accdb. Rename the database whatever you, want. In the example below, we named the database, Ready2Read because it's the name of the store in our, scenario., Fig 3, , Copa 1225803, , -, , Copa 1225802, , Because we're planning a database to track our, customers, the books we have, and the orders our, customers place, we will need a table for each one of, these., , Pin/Zip Code, Email, We will also need several fields in the Books table. Title, and Author make sense for books. We'll need a Price for, each book. Category will help usknow what type of books, sell the best so we can order more books that fit into this, category., The Orders table will have fewer fields. We'll need this, table to track the Customer who is placing the order, the, 154, , Click Create to finish naming the database., Setting up tables, The new database opens with one table showing as a, default. It also defaults to naming this table Table1 in both, the navigation pane and the Table tab itself. You will want, to name your tables based on your database design plan., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Copa 1225804, , Naming a table, To give the table a unique name, you must first click on, the Microsoft Office button in the upper-left corner of the, application., , Copa 1225807, , Fig 7, , Fig 4, , TIP: Give your tables logical, easy-to-understand names., To rename a table:, With the table closed, right-click the Table you want to, rename in the navigation pane. Select the Rename option, that appears in the menu., Fig 8, , Next, select Save from the menu. The Save As dialog box, will appear to let you save the table whatever name you, want., Fig 6, , Copa 1225808, , Copa 1225805, , Fig 5, , The table name will be highlighted and a cursor will appear,, which means you can now type the new name right there., Left-click anywhere outside of the table name to make the, change., To close a table:, , Copa 1225806, , There are several ways to close an active table. You can, right-click the Table tab and choose Close from the menu., Fig 9, , Copa 1225809, , The new table names appear in both the navigation pane, and the Table tab itself, as you can see in the picture, below., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 155
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A more common method is to click the X that appears in, the top-right corner of the active database object window., , Copa 12258010, , Fig 10, , To open a table:, To open a table, right-click the Table name of the table, you want to open in the navigation pane, then choose, Open from the menu., , Fig 11, , Next, select Table from the Tables command group. A, new table will open in the active database object window., You must name your table using the Save command, from Microsoft Office menu., Adding fields to a table, Access 2007 allows you to add fields to tables when you, are:, •, , Working in Datasheet view, which looks like a, spreadsheet, , •, , Working in Design view, where you are able to set more, controls for your fields, , Either way, you need to know how to switch between the, two views., To switch views:, Select the Views command group from either the Home, tab (seen below) or the Datasheet tab on the Ribbon. Select, the view option you want from the menu., , A more common method is to double-click the table name, in the navigation pane. The selected table will open in, the active database object window., Adding more tables to the database, By default, Access 2007 starts out with one table. To add, more tables to the database, click the Create tab on the, Ribbon., , Fig 12, , Copa 12258013, , Copa 12258011, , Fig 13, , Adding fields in Datasheet view, By default, Access 2007 creates one field in each new, table: the ID field. This field auto-numbers to give each, record in the table a unique number identifier. Recall, that records are the rows in a table. You may want to, rename the ID field with a unique name because the ID, field appears automatically in every table you create., While this is not necessary, it may help avoid confusion, when setting up table relationships., , 156, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258014, , Copa 12258012, , Fig 14
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To add more fields to a table in Datasheet view, doubleclick the Add New Field header., Fig 15, , To add a new field to a table in Design view, click in the, cell where you want the new field and type the field name., When you switch back to Datasheet view, your new field, appears as its own column, as seen below., , The Add New Field text will disappear from the header., Name the field by typing the name directly into the header., Press the Tab key on your keyboard to move to the next, field., Adding fields in Design view, In Design view, the field names are along the lefthand, column instead of across the top like in Datasheet view,, as seen below., , Copa 12258017, , Copa 12258015, , Fig 17, , Datatypes, Every field in a table has properties and these properties, define the field's characteristics and behavior. The most, important property for a field is its data type. A field's data, type determines what kind of data it can store. MS Access, supports different types of data, each with a specific, purpose., •, , The data type determines the kind of the values that, users can store in any given field., , •, , Each field can store data consisting of only a single, data type., , Copa 12258016, , Fig 16, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 157
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Here are some of the most common data types you will find used in a typical Microsoft Access database., Type of Data, , Description, , Size, , Text or combinations of text and numbers,, Short Text, , Up to 255, , including numbers that do not require, characters. calculating (e.g. phone numbers)., , Long Text, , Lengthy text or combinations of text and, , Up to 63, 999, , numbers. characters., Numeric data used in mathematical, Number, , 1, 2, 4, or 8 bytes, , (16 bytes if set to calculations., Replication ID)., , Date/Time, , Date and time values for the years 100 through, , 8 bytes., , 9999., Currency values and numeric data used in, Currency, , mathematical calculations involving data with, , 8 bytes., , one to four decimal places., A unique sequential (incremented by 1), , 4 bytes (16 bytes if, , number or random number assigned by, AutoNumber, , set to Replication Microsoft Access whenever, a new record is ID). added to a table., Yes and No values and fields that contain only, , Yes/No, , 158, , one of two values (Yes/No, True/False, or, , 1 bit., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Here are some of the other more specialized data types, you can choose from in Access., Data Types, , Description, , Attachment, , Size, , Files, such as digital photos. Multiple files can be, attached per record. This data type is not available, , Up to about 2 GB., , in earlier versions of Access., OLE objects, , OLE objects can store pictures, audio, video, or, , Up to about 2 GB., , other BLOBs (Binary Large Objects), Hyperlink, , Text or combinations of text and numbers stored a, , Up to 8,192 (each, part of a Hyperlink, data type can, contain up to, 2048 characters)., , Lookup, , The Lookup Wizard entry in the Data Type column, in the Design view is not actually a data type. When, you choose this entry, a wizard starts to help you, , Dependent on, , define either a simple or complex lookup field., , the data type of, he lookup field., , Wizard, , A simple lookup field uses the contents of another, table or a value list to validate the contents of a, single value per row. A complex lookup field allows, you to store multiple values of the same data type, in each row., , Calculated, , You can create an expression that uses data from, , You can create, , one or more fields. You can designate different, , an expression, , result data types from the expression., , that uses data, from one or, more fields. You, can designate, different result, data types from, the expression., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 159
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MS Access - Adding Data, , Fig 21, , Adding records to tables, , Copa 12258021, , When you enter records into your table, you are, populating the database. In Access 2007, you can do this, a few different ways., To add records in the new record row:, Click the record row with the asterisk that appears at, the bottom of the table., •, Copa 12258018, , Fig 18, , Type the data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , To add records with the New Record navigation, button:, •, , Click the New Record button in the navigation bar. The, navigation bar is located in the bottom-left corner of, the open object pane., , Fig 22, , •, , Type the new information into the field., , •, , Click outside of the record row to apply the change., , To edit a record using Find and Replace:, •, , Click the Find command in the Find group on the, Ribbon., , Fig 23, Copa 12258023, , •, , Click the cell containing the information that must be, edited. A pencil icon appears to indicate edit mode., Copa 12258022, , •, , Copa 12258019, , Fig 19, , •, , Type data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , •, , The Find and Replace dialog box opens., , Fig 24, , •, , Copa 12258024, , To add records with the New Record command:, Click the New Record command in the Records group, in the Ribbon., Copa 12258020, , Fig 20, , •, , Tell Access what to find by typing it into the Find What:, area., , •, , Type the replace term in the Replace With: area., , •, , Tell Access where to look with the Look In: drop-down, list. The first choice in the drop-down list is the field, you were last in within the table., , Editing records in tables, , •, , Sometimes it is necessary to edit records in the database., Like with every other task in Access 2007, this can be, done several different ways., , Tell Access what to Match: Any part of the field, the, whole field, or just the start of the field., , •, , Tell Access how to Search: Up finds records above, the cursor, Down finds records below the cursor, and, All searches all records., , •, , Click one of the action options:, , -, , Find Next will find the next instance of the word, in the table., , •, , Type the data into the appropriate fields., , •, , Hit the Enter or the Tab key to move to the next field., , To edit a record directly:, •, , Scroll through the records, or use the navigation, buttons on the navigation bar to find the record to, edit., , 160, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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-, , Replace will put the new word into the table, overwriting, what is currently there., , -, , Cancel stops the editing process., , CAUTION: DO NOT use Replace All because it will, overwrite every instance of the Find term in the table,, which can have a serious impact on your data., To copy and paste a Record:, •, , Select the record you want to copy. Right-click, then, select Copy., , •, , Select the new record row. Right-click and select Paste., The record information appears with a new record ID, number., , To delete a record:, •, , Select the record you want to delete, then right-click, and select Delete Record., , •, , A dialog box appears, telling you the action cannot, be undone and asking if you are sure you want to, delete the record., , Let's say one of your database users has entered an order, date of January 4, 2008, in the month/date/year format as, 01/04/2008. Another user has entered an order placed on, that same date in the day/month/year format as 04/01/, 2008. If the database is tracking all sales for the month of, January 2008, it may not show both orders as placed in, January, even though both were placed on the same date., Access 2007 allows you to set field properties and data, validation rules to force the person entering data to, follow a specific format., Data types and validation rules, Data validation begins when data types are set during, the process of building tables and fields. For example, if, a field data type had been set to Currency and a text, value is entered in that table field during data entry,, Access will not accept an invalid format and will display a, validation error, like the one below., , Fig 27, , There may be other records that rely on the record you, are trying to delete. DO NOT delete a record without, knowing how it will impact the rest of your database., Fig 26, , Copa 12258027, , Copa 12258025, , Fig 25, , Data validation is accomplished by setting data validation, rules and other field properties for various fields., To set data validation rules:, •, , In Design view, highlight the field that requires a, validation rule., , •, , In the Field Properties section at the bottom half of, the window, set your validation rule using, theExpression Builder. The Expression Builder offers, common syntax to set up a data validation rule., , When you delete a record, the record number is, permanently deleted from the database table. If you, delete the last record from a table and then add a new, record, your new record numbers will appear to be out of, sequence., Data validation, Data validation is an important database concept. It is, the process by which Access tests the data that is being, entered into the database to make sure it is in an, acceptable-or valid-format., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258028, , Copa 12258026, , Fig 28, , 161
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The image below shows the resulting error message, users would see when the Category validation rule has, been broken., , Fig 29, , Validation rules work most easily with numerical fields., Rules for text fields require you to enclose each, acceptable value inside its own quotation marks,, separating them with Or, as seen above., , Copa 12258031, , Copa 12258029, , Fig 31, , Using field properties to ensure data integrity, Another way to ensure data integrity is by setting field, properties such as Field Size, Format, and Required., •, , Validation text is a specialized error message you can, set to have Access tell the user entering data the specific, way you want that person to enter it., , Field Size can be set to hold a specific number of, characters, up to as many as 255 for text fields. If, you were using a text field to hold the two-letter state, postal abbreviation, the field size could be set to 2 to, ensure no one enters a full state name into this field., , •, , To set the validation text, enter the error message exactly, as you want it to appear to users in the row directly, beneath the Validation Rule row in the Field Properties, section of Design view. For the validation rule we set for, Category, you'd set the validation text like this:, , The Format field property can be set to display text, or numbers in a standardized way. For example, text, can be set to show as all uppercase, and numbers, can be set to show scientific numbers, percentages,, or decimals., , •, , Set the Required property to Yes if you want users, entering data to be required to enter something in, the field. Choose No if users are allowed to leave the, field blank., , Validation text, , Fig 30, , Copa 12258030, , These are just some ways Access helps you ensure data, being entered into your database is valid., , 162, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.9.62 to 1.9.66, COPA - Database Management Systems, Forms, quires, and reports in access, Objectives : At the end of this lesson you shall be able to, • explain database relationship and forms, • explain quires and reports in as access, In a relational database (Access), the data in one table is, related to the data in other tables. In general, tables can, be related in one of three different ways: one-to-one, oneto-many or many-to-many. The relationship is used to, cross reference information between tables., , Defining relationships, , One to One, , •, , The kind of relationship that Microsoft Access creates, depends on how the related fields are defined:, , •, , A one-to-many relationship is created if only one of, the related fields is a primary key or has a, , •, , A one-to-one relationship is created if both of the, related fields are primary keys or have unique, indexes., , •, , A many-to-many relationship is really two one-tomany relationships with a third table whose primary, key consists of two fields the foreign keys from the, two other tables., , In a one-to-one relationship each record in one table, has at most one related record in another table., In a one-to-one relationship, each record in Table A can, have only one matching record in Table B, and each, record in Table B can have only one matching record in, Table A. This type of relationship is not common, because, most information related in this way would be in one, table. You might use a one-to-one relationship to divide, a table with many fields, to isolate part of a table for, security reasons, or to store information that applies only, to a subset of the main table., , You define a relationship by adding the tables that you, want to relate to the Relationships window, and then, dragging the key field from one table and dropping it on, the key field in the other table., , One to Many, , move a table that appears in the relationship map:, , A one-to-many relationship, often referred to as a, "master-detail" or "parent-child" relationship., , •, , Place your mouse over the table you want to move., , •, , Hold down the left mouse button, then drag the table, to a new location., , •, , Release the mouse button to drop the table in its new, place., , Many to Many, In a many-to-many relationship, a record in Table A can, have many matching records in Table B, and a record in, Table B can have many matching records in Table A., This type of relationship is only possible by defining a, third table (called a junction table) whose primary key, consists of two fields the foreign keys from both Tables, A and B. A many-to-many relationship is really two oneto-many relationships with a third table., , Understanding the relationship map, The relationship map lists all of the tables that were, selected to relate, as well as all of the fields that were, previously set up for that table. Notice that the first field, has a key icon next to it. This is the primary key for the, table., , Fig 32, , A many-to-many relationship means that for each record, in one table there can be many records in another table, and for each record in the second table there can be, many in the first., , Copa 12258032, , A one-to-many relationship is the most common type of, relationship. In a one-to-many relationship, a record in, Table A can have many matching records in Table B, but, a record in Table B has only one matching record in Table, A., , Many-to-many relationships can not be directly, represented in relational database programs and have, to be built by using two or more one-to-many, relationships., , Copyright @ NIMI Not to be Republished, , 163
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Primary and foreign keys, , Bound Forms, , A primary key is the first field in each table of the, database. You may recall that this field auto-numbers, by default, so every record in the table has its own unique, number to identify it. Access uses this number to quickly, pull information together when you run queries or reports,, which are covered later., , •, , Let us now understand what Bound Forms are ?, , •, , Bound forms are connected to some underlying data, source such as a table, query, or SQL statement., , •, , Bound forms are what people typically think of when, they think of the purpose of a form., , In the example above, the primary key for the Customers, table is Customer ID, the primary key for the Orders, table is Order ID, and the primary key for the Books, table is Book ID., , •, , Forms are to be filled out or used to enter or edit data, in a database., , •, , A foreign key is a field that is the primary field in its own, table but that shows up in another table. If you look closely, at the Orders table, the fields Customer ID and Book ID, appear there, as well as in their own respective tables., These fields are the primary key in their own tables, but, in the Orders table, they are considered foreign keys., , Examples of bound forms will typically be what users, use to enter, view or edit data in a database., , Unbound Forms, , Copa 12258033, , Fig 33, , Forms, A form is a database object that you can use to enter,, edit, or display data from a table or a query. You can use, forms to control access to data, such as which fields of, data are displayed. For example, certain users may not, need to see all of the fields in a table. Providing those, users with a form that contains just the necessary fields, makes it easier for them to use the database., , Let us look into Unbound Forms:, •, , These forms are not connected to an underlying, record or data source., , •, , Unbound forms could be dialog boxes, switch boards,, or navigation forms., , •, , In other words, unbound forms are typically used to, navigate or interact with the database at large, as, opposed to the data itself., , Types of Bound Forms, There are many types of bound forms you can create in, Access. Let us understand the types ?, Single Item Form, This is the most popular one and this is where the records, are displayed - one record at a time., Multiple Item Form, This displays multiple records at a time from that bound, data source., , create a form with a single click,, , Split Form, , 1. Open the table or query upon which you want to base, theform., , The form is divided into halves, either vertically or, horizontally. One half displays a single item or record,, and the other half displays a list or provides a datasheet, view of multiple records from the underlying data source., , 2. To create a form on which all fields from the underlying, table or query are placed, displaying one record at a, time, on the Create tab, clickForm., Copa 12258034, , Fig 34, , Forms in Access are like display cases in stores that, make it easier to view or get the items that you want., Since forms are objects through which you or other users, can add, edit, or display the data stored in your Access, desktop database, the design of your form is an important, aspect. There's a lot you can do design-wise with forms, in Microsoft Access. You can create two basic types of, forms -, , Bound forms, , -, , Unbound forms, , 164, , Form Controls, Every object on a form or report is a control and has its, own set of properties (displayed in the Property list) that, determine the characteristics of the data it contains., Some controls are linked to fields in the underlying table, or query and some are merely text or graphical objects, not related to any data source. Two of the most commonly, used controls in a form or report are text boxes and labels., 1) Label: displays unchanging or informational text often, times as headings or titles. Labels do not come from a, source in the database such as a field or expression., This is called an unbound control because it is not bound, to any data source., 2) Text Box: displays data as text and is abound control.A, bound control displaysinformation that is stored in a field, from the data Text boxes are used to display, enter, and, update values from fields in your database., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Form Sections, , Item Total:[Quantity]*[Price], , Forms consist of header, footer, and detail sections. In, forms, there are two types of headers/footers. Form, headers and footers are visible on every page of the, form. Page headers/footers only appear on a printed copy, of a form. There are never visible in Form View., Information about individual records appears in the detail, sections., , Use the Expression Builder to create calculated or, concatenated fields, , Copa 12258035, , Fig 35, , Sizing Sections, Adjust the size of the area for any of the sections, (headers, footers, detail), by dragging the horizontal, border for that section with your mouse. To adjust line, spacing in the detail section, drag the Detail border. There, is no other line spacing control., Working with Queries, Queries are questions you ask of your database. They, allow you to select certain fields out of a table, or pull, together data from various related tables and display it, together. Queries can be used to perform calculations,, and to edit the data in your tables. Queries can also form, the basis of forms and reports., Query Results, •, , •, , If a query contains fields from two or more related, tables, the results will only include records that have, related records in all the tables. (In other words, in, the query shown above, customers without records, in the Orders table will not appear in the query results.), To display such records, use an outer join (see page, 6) in your query., , You can simplify the process of creating concatenated, fields and other expressions with the Expression Builder., Create a blank column in your query grid and then click, the Builder button in the Query Setup group on the Query, Design Ribbon. The Expression Builder opens., Type the expression in the large box at the top. One, advantage is that you have way more room to type and, see your expression than you have at the top of a query, grid column!, A second advantage is that you can add fields to the, expression by double clicking them in the Expression, Categories column rather than by typing them. This, removes the possibility of typos., Fig 36, , WARNING! Any change you make in a query (adding,, deleting or editing data) WILL BE CHANGED IN THE, TABLES TOO!!!, , Sort query results, , Copa 12258036, , In Design View, click the Sort row in the column you, wish to sort by. A dropdown arrow appears; choose, Ascending or Descending. If you sort by more than one, column, the sorts will be done left-to-right., Create a concatenated field in a query, Concatenated fields combine information from two or, more fields into one. Ex: Combine first and last names, into one field, called "FullName". In Design View, click, in a blank column and type the following:, FullName:[FirstName]&" "&[LastName], (Type a space between the two sets of quotation marks,, and use square brackets around the field names.), Create a calculated field in a query, , Specify criteria in a query (Filtering), In Query Design View, click in the criteria row for the, field you want to filter, and type the criteria (ex: type, "OH" in the criteria row of the State field). When you run, the query, only records matching the criteria., , In Design View, click in a blank column and type a, mathematical expression, typing field names in square, brackets. Any of the normal mathematical operators (+ * / ^) can be used. If desired, give the expression a name, as in the sample below. The following expression, calculates a total cost by multiplying quantity times price:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 165
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Using Multiple Criteria, , Fig 37, , Copa 12258037, , You can type criteria in more than one field., •, , Criteria typed on the same line must all be met for a, record to be displayed ("AND" logic). Ex: "OH" in the, state field and "Smith" in the LastName field pulls up, only Ohio-dwelling Smiths., , •, , If criteria are typed on different lines, records matching, any of them will be retrieved ("OR" logic). Ex: "WA", and "OH" on different lines in the State field retrieves, records for both states., , Criteria Ranges, Criteria ranges broaden and customize a search. Type a, criteria range instead of a single value in the Criteria, row of the query grid., Criteria, <, , <=, , Example, , Description and Result, , <14, , Finds records where the field is less than a, certain value., Records will have values under 14., , <= #2/2/2006#, , Finds records where the field is less than, or equal to a, certain value., Records will have dates on or before February, 2, 2006, Note: dates are enclosed between # signs., , >, , >100, , Similar to above: Finds records where the, value is, , >=, , >=100, , greater than 100. The second expression displays, records where the value is greater than or, equal to 100., , =, , ="Diana", , Finds records where the value in the field is Diana., Note: text is enclosed in double quotes., , 166, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Expressions like these may be combined - for example,, a criteria of <49 Or>=100 would return records with, values below 49, or 100 or above, but not ones with, values between 49 and 99.99., Between __ And __, , Between 1 and 4, , Finds records where the field is between, the endpoints., , Is Null, , Is Null, , Finds records where the field is empty., , Is Not Null, , Is Not Null, , Finds records where the field is not empty., , Like, , Like U*, , Finds records where the criteria match parts, of the field., , Like "[U-X]*", , The * wildcard stands for any number of, characters, and, , Like, "*Korea*", , the ?wildcard stands for a single character., , Like "*ina", , The sample criteria will return records where, the field, , Like "Chi??", , 1) starts with U; 2) starts with U, V, W or X,, 3) contains, , Like "*4.99", , the letters 'Korea'; 4) ends in the letters, 'ina' as in ballerina;, 5) has five letters and begins with the letters, 'Chi' as in Chile or China; 6) is a number and, ends in the digits '4.99' as in 24.99., , Create a parameter query, , Fig 38, , Copa 12258038, , Parameters make queries flexible by letting users choose, their own criteria each time they run the query. In the, criteria box, type a phrase in square brackets; Access, will use this phrase to prompt the user for a value. Ex: In, a State field, type [Enter a state]. If the user types CA,, only California records will be retrieved., Specify a range in a parameter query, In the criteria box, type the following:, Between [___] And [____], Inside the brackets, type text telling the user what kind, of information to enter., Inner Joins vs. Outer Joins, Excel normally uses inner joins in its queries. These, queries return only those rows from both tables in the, join that match on the joining field (e.g., customers in, the Customers table with corresponding orders in the, Orders table.), If you need to display all customers, with or without, orders, as well as any available order information, you, need to use an outer join., In the query tray, double click the join line between two, related tables. The Join Properties dialog box will appear:, , Select button 2 or 3 depending on which field's records, you want to display completely., Action Queries, Action queries modify groups of records in one fell swoop., Types of action queries include:, •, , Update Queries (modify all records in a table that, meet specific criteria - ex: change the tax rate for all, Ohio customers from 5.75% to 6%), , •, , Delete Queries (remove records from a table - ex:, delete all customers whose last order date is more, than 2 years ago), , •, , Append Queries (add records to an existing table ex: at the end of the year, add the year's orders to the, end of an archive table), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 167
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•, , Make-table Queries (create a new table - ex: extract a, subset of records into a new table, for a subordinate, who needs Ohio customers only), , Other Specialized Queries, Instructions for creating and running these special query, types can be found in the Access help manual by clicking, the Help button in the upper right corner of the screen, (Internet connection required)., Find Duplicates query: Lets you locate duplicate records, in a table by displaying a field containing duplicate values, alongside other fields for comparison, to help you tell if, the record is really a duplicate., , 168, , Find Unmatched query: Lets you compare two tables, and identify records in one of the tables that have no, corresponding records in the other table., Crosstab query: This is a special type of Totals query, that presents summary information in a compact format, that is similar to a spreadsheet., Union query: Lets you review all of the data that is, returned by several similar select queries together, as a, combined set., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.67 - 1.10.69, , Concepts of network and internet, Objectives : At the end of this lesson you shall be able to, • define computer network and its advantages and disadvantages, • name and explain the types of network and their characteristics, • explain the types of topologies, • state about the cables used for network system, • name and state about the various connectors used in network system, • explain about the hub, modem and internet, • describe about the internet protocols connection sharing (ICS) using windows., Define computer network, , •, , A computer network is an interconnection of various, computer systems located at different places. In, computer network two or more computers are linked, together with a medium and data communication devices, for the purpose of communicating data and sharing, resources. The computer that provides resources to other, computers on a network is known as server. In the, network the individual computers, which access shared, network resources, are known as workstations or nodes., , Workgroup Computing: Workgroup software like, Microsoft BackOffice enables many users to, contribute to a document concurrently. This allows, for interactive teamwork., , •, , Error reduction and improve consistency: One, can reduce errors and improve consistency by having, all staff work from a single source of information, so, that standard versions of manuals and directories can, be made available, and data can be backed up from, a single point on a scheduled basis, ensuring, consistency., , Advantages of Computer Networks, The following are some of the advantages of computer, networks., •, , •, , •, , •, , •, , File Sharing: Networks offer a quick and easy way, to share files directly. Instead of using a disk or USB, key to carry files from one computer or office to, another, you can share files directly using a network., Security: Specific directories can be password, protected to limit access to authorized users. Also,, files and programs on a network can be designated, as "copy inhibit" so you don't have to worry about the, illegal copying of programs., Resource Sharing: All computers in the network can, share resources such as printers, fax machines,, modems, and scanners., Communication: Even outside of the internet, those, on the network can communicate with each other via, electronic mail over the network system. When, connected to the internet, network users can, communicate with people around the world via the, network., Flexible Access: Networks allow their users to access, files from computers throughout the network. This, means that a user can begin work on a project on, one computer and finish up on another. Multiple users, can also collaborate on the same project through the, network., , Network Application Areas, There is a long list of application areas, which can be, benefited by establishing Computer Networks. Few of, the potential applications of Computer Networks are:, 1 Information retrieval systems which search for books,, technical reports, papers and articles on particular, topics, 2 News access machines, which can search past news,, stories or abstracts with given search criteria., 3 Airline reservation, hotel booking, railway-reservation,, car-rental, etc., 4 A writer's aid: a dictionary, thesaurus, phrase, generator, indexed dictionary of quotations, and, encyclopaedias., 5 Stock market information systems which allow, searches for stocks that meet certain criteria,, performance comparisons, moving averages, and, various forecasting techniques., 6 Electronic Fund Transfer (EFT) between banks and via, cheque clearing house., 7 Games of the types that grow or change with various, enthusiasts adding to the complexity or diversity., 8 Electronic Mail Messages Systems (EMMS)., , Copyright @ NIMI Not to be Republished, , 169
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9 Corporate information systems such as marketing, information system, customer information system,, product information system, personnel information, system, etc., , A classification of computer networks can be done to distance as in the table., Interprocess (or), Distance, , 10 Corporate systems of different systems such as Order-Entry System, Centralized Purchasing, Distributed Inventory Control, etc., 11 On-line systems for Investment Advice and Management, Tax Minimization, etc., 12 Resources of interest to a home user., 13 Sports results., 14 Theatre, movies, and community events information., 15 Shopping information, prices, and advertisements., 16 Restaurants; good food guide., 17 Household magazine, recipes, book reviews, film reviews., 18 Holidays, hotels, travel booking., 19 Radio and TV programmes., 20 Medical assistance service., 21 Insurance information., 22 Computer Assisted Instruction (CAI)., , Network Type, , 0 to 1 Km, , Local Area Network (LAN), , 1 Km to 10 Km, , Metropolitan Area, Network (MAN), , 10 Km to 1000 Km, , Wide Area Network (WAN), , Above 1000 Km, , Internet, , Local Area Network (LAN), Networks used to interconnect computers in a single, room, rooms within a building or buildings on one site, are called Local Area Network (LAN). LAN transmits data, with a speed of several megabits per second (106 bits, per second). The transmission medium is normally coaxial cables., LAN (Fig 1) links computers, i.e., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited, geographical area because they must be connected by, a cable, which is quite expensive. People working in LAN, get more capabilities in data processing, work processing and other information exchange compared to standalone computers. Because of this information exchange, most of the business and government organisations are, using LAN., , 23 School homework, quizzes, tests., 24 Message sending service., 25 Directories., 26 Consumer reports., 27 Employment directories and Job opportunities., 28 Tax information and Tax assistance., 29 Journey planning assistance viz. Train, bus, plane, etc., , Major Characteristics of LAN, •, , every computer has the potential to communicate with, any other computers of the network, , •, , high degree of interconnection between computers, , Computer Networks may be classified on the basis of, geographical area in two broad categories., , •, , easy physical connection of computers in a network, , •, , inexpensive medium of data transmission, , 1 Local Area Network (LAN), , •, , high data transmission rate, , 2 Wide Area Network (WAN), , Types of Connection, , 30 Catalogue of Open University and Virtual University, courses., , 3 Metropolitan Area Network (MAN), , 170, , Peer to Peer: Peer to peer is an approach to computer, networking where all computers share equivalent, responsibility for processing data. Peer-to-peer, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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networking (also known simply as peer networking) differs, from client-server networking, where certain devices have, responsibility for providing or "serving" data and other, devices consume or otherwise act as "clients" of those, servers., , who sells the service to the users., 3 A MAN often acts as a high speed network to allow, sharing of regional resources. It is also frequently used, , Client server: The term client-server refers to a popular, model for computer networking that utilizes client and, server devices each designed for specific purposes. The, client-server model can be used on the Internet as well, as LAN., Advantages of LAN, •, , The reliability of network is high because the failure, of one computer in the network does not affect the, functioning for other computers., , •, , Addition of new computer to network is easy., , •, , High rate of data transmission is possible., , •, , Peripheral devices like magnetic disk and printer can, be shared by other computers., , Disadvantages of LAN, If the communication line fails, the entire network system, breaks down., Use of LAN, Followings are the major areas where LAN is normally, used, •, , File transfers and Access, , •, , Word and text processing, , •, , Electronic message handling, , •, , Remote database access, , •, , Personal computing, , •, , Digital voice transmission and storage, , to provide a shared connection to other networks using, a link to a WAN., Campus Area Network (CAN), A Campus Area Network or Corporate Area Network, (CAN) is a network is made up of an interconnection of, local area network within a limited geographical area. A, , Metropolitan Area Network (MAN), A Data network designed for a town or city. In terms of, geographic breadth, MANs are larger than, but smaller, than. MANs (Fig 2) are usually characterized by very, high-speed connections using or other digital media., Characteristic of MAN, 1 The network size falls intermediate between LANs, and WANs. A MAN typically covers an area of, between 5 and 50 km range. Many MANs cover an, area the size of a city, although in some cases MANs, may be as small as a group of buildings., 2 A MAN (like a WAN) is not generally owned by a, single organisation. The MAN, its communications, links and equipment are generally owned by either a, consortium of users or by a network service provider, , CAN (Fig 3) is larger than a local area network but smaller, than a Wide area Network, Wide Area Network (WAN), The term Wide Area Network (Fig 4) is used to describe a, computer network spanning a regional, national or global, area. For example, for a large company the head quarters, might be at Delhi and regional branches at Bombay,, Madras, Bangalore and Calcutta. Here regional centres, are connected to head quarters through WAN. The distance, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 171
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erate nationwide or even worldwide., , between computers connected to WAN is larger. Therefore, the transmission mediums used are normally telephone, lines, microwaves and satellite links., Characteristics of WAN, Followings are the major characteristics of WAN., 1 Communication Facility: For a big company, spanning over different parts of the country the, employees can save long distance phone calls and it, overcomes the time lag in overseas communications., Computer conferencing is another use of WAN where, users communicate with each other through their, computer system., 2 Remote Data Entry: Remote data entry is possible, in WAN. It means sitting at any location you can enter data, update data and query other information of, any computer attached to the WAN but located in, other cities., 3 Centralised Information: In modern computerised, environment you will find that big organisations go, for centralised data storage. This means if the, organisation is spread over many cities, they keep, their important business data in a single place. As, the data are generated at different sites, WAN permits collection of this data from different sites and, save at a single site., , •, , In LAN, the computer terminals and peripheral devices are connected with wires and coaxial cables., In WAN there is no physical connection. Communication is done through telephone lines and satellite links., , •, , Cost of data transmission in LAN is less because the, transmission medium is owned by a single, organisation. In case of WAN the cost of data transmission is very high because the transmission medium used is hired either telephone lines or satellite, links., , •, , The speed of data transmission is much higher in, LAN than in WAN. The transmission speed in LAN, varies from 0.1 to 100 megabits per second. In case, of WAN the speed ranges from 1800 to 9600 bits per, second (bps)., , •, , Few data transmission errors occur in LAN compared, to WAN. It is because in LAN the distance covered is, negligible., , Open Systems Interconnection (OSI), The Open Systems Interconnection (OSI) model is a reference tool for understanding data communications between any two networked systems. It divides the communications processes into seven layers. Each layer both, performs specific functions to support the layers above, it and offers services to the layers below it. The three, lowest layers focus on passing traffic through the network to an end system. The top four layers come into, play in the end system to complete the process., An Overview of the OSI Model (Fig 5), Application Layer (Layer 7): This layer interfaces directly to and performs common application services for, the application processes. The common application services provide semantic conversion between associated, application processes. Examples of common applica-, , Examples of WAN, 1 Ethernet: Ethernet developed by Xerox Corporation, is a famous example of WAN. This network uses coaxial cables for data transmission. Special integrated, circuit chips called controllers are used to connect, equipment to the cable., 2 Arpanet: The Arpanet is another example of WAN. It, was developed at Advanced Research Projects, Agency of U. S. Department. This Network connects, more than 40 universities and institutions throughout, USA and Europe., Difference between LAN and WAN, •, , LAN is restricted to limited geographical area of few, kilometers. But WAN covers great distance and op-, , 172, , tion services include the virtual file, virtual terminal (for, example, Telnet), and"Job transfer and Manipulation protocol" (JTM, standard ISO/IEC 8832), Presentation Layer (Layer 6): The Presentation layer, relieves the Application layer of concern regarding syntactical differences in data representation within the enduser systems. MIME encoding, encryption and similar, manipulation of the presentation of data are done at this, layer. An example of a presentation service would be, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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the conversion of an EBCDIC-coded text file to an ASCIIcoded file., Session Layer (Layer 5): The Session layer provides the, mechanism for managing the dialogue between end-user, application processes. It provides for either duplex or halfduplex operation and establishes check pointing, adjournment, termination, and restart procedures. This layer is, responsible for setting up and tearing down TCP/IP sessions., Transport Layer (Layer 4): The purpose of the Transport layer is to provide transparent transfer of data between end users, thus relieving the upper layers from, any concern with providing reliable and cost-effective, data transfer. The transport layer controls the reliability, of a given link. Some protocols are state ful and connection oriented. This means that the transport layer can, keep track of the packets and retransmit those that fail., The best known example of a layer 4 protocol is TCP., Network Layer (Layer 3): The Network layer provides, the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer. The Network layer performs network routing, flow control, segmentation/desegmentation, and error control functions., The router operates at this layer - sending data throughout the extended network and making the Internet possible, although there are layer 3 (or IP) switches. This is, a logical addressing scheme - values are chosen by the, network engineer. The addressing scheme is hierarchical., Data Link Layer (Layer 2): The Data link layer provides, the functional and procedural means to transfer data, between network entities and to detect and possibly correct errors that may occur in the Physical layer. The addressing scheme is physical which means that the addresses (MAC) are hard-coded into the network cards at, the time of manufacture. The addressing scheme is flat., Physical Layer (Layer 1): The physical layer defines, all electrical and physical specifications for devices. This, includes the layout of pins, voltages, and cable specifications. Hubs and repeaters are physical-layer devices., The major functions and services performed by the physical layer are:, •, , Establishment and termination of a connection to a, communications medium., , •, , Participation in the process whereby the communication resources are effectively shared among multiple users. For example, contention resolution and, flow control., , •, , Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications, , channel. These are signals operating over the physical, cabling - copper and fiber optic, for example. SCSI, operates at this level., Network Topology, The physical topology of a network refers to the configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which is the method used to pass information between workstations., Main Types of Physical Topologies, •, , LINEAR BUS, , •, , STAR, , •, , RING, , •, , TREE, , •, , MESH, , Linear Bus Topology, , A linear bus topology (Fig 6) consists of a main run of, cable with a terminator at each end. All nodes (file server,, workstations, and peripherals) are connected to the linear cable., Advantages of a Linear Bus Topology, •, , Easy to connect a computer or peripheral to a linear, bus., , •, , Requires less cable length than a star topology., , Disadvantages of a Linear Bus Topology, •, , Entire network shuts down if there is a break in the, main cable., , •, , Terminators are required at both ends of the backbone cable., , •, , Difficult to identify the problem if the entire network, shuts down., , •, , Not meant to be used as a stand-alone solution in a, large building., , Star Topology, A star topology (Fig 7) is designed with each node (file, server, workstations, and peripherals) connected directly, to a central network hub, switch, or concentrator, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 173
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Data on a star network passes through the hub, switch, or, concentrator before continuing to its destination. The hub,, switch, or concentrator manages and controls all functions of the network. It also acts as a repeater for the data, flow., This configuration is common with twisted pair cable;, however, it can also be used with coaxial cable or fiber, optic cable., Advantages of a Star Topology, •, , Easy to install and wire., , •, , No disruptions to the network when connecting or, removing devices., , •, , Easy to detect faults and to remove parts., , Disadvantages of a Star Topology, •, , Requires more cable length than a linear topology., , •, , If the hub, switch, or concentrator fails, nodes attached, are disabled., , •, , More expensive than linear bus topologies because, of the cost of the hubs, etc., , •, , There is no need for network server to control the, connectivity between workstations., , •, , Additional components do not affect the performance, of network., , •, , Each computer has equal access to resources., , Disadvantages of Ring Topology, •, , Each packet of data must pass through all the computers between source and destination., , •, , If one workstation or port goes down, the entire network gets affected., , •, , Network is highly dependent on the wire which connects different components., , •, , MAU's and network cards are expensive as compared, to Ethernet cards and hubs., , Tree or Expanded Star, A tree topology (Fig 9) combines characteristics of linear bus and star topologies. It consists of groups of starconfigured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of, an existing network, and enable schools to configure a, network to meet their needs., , Ring Topology, , Advantages of a Tree Topology, , The ring topology (Fig 8) is one which the network is a, loop where data is passed from one workstation to another., , •, , Point-to-point wiring for individual segments., , •, , Supported by several hardware and software vendors., , Advantages of Ring Topology, •, , This is very organized. Each node gets to send the, data when it receives an empty token. This helps to, reduces chances of collision. Also in ring topology all, the traffic flows in only one direction at very high, speed., , 174, , Disadvantages of a Tree Topology, •, , Overall length of each segment is limited by the type, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Disadvantages of Mesh topology, •, , There are high chances of redundancy in many of the, network connections., , •, , Overall cost of this network is way too high as compared to other network topologies., , of cabling used., , •, , •, , If the backbone line breaks, the entire segment goes, down., , Set-up and maintenance of this topology is very difficult. Even administration of the network is tough., , PROTOCOLS, , •, , More difficult to configure and wire than other topologies., , Network Protocol, , Advantages of Mesh topology, , A network protocol defines rules and conventions for, communication between network devices. Protocols for, computer networking all generally use packet switch techniques to send and receive messages in the form of, packets. Network protocols include mechanisms for devices to identify and make connections with each other,, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols, also support message acknowledgement and data compression designed for reliable and/or high-performance, network communication. Hundreds of different computer, network protocols have been developed each designed, for specific purposes and environments., , •, , Parameters of Protocol, , Mesh Topology, A network setup where each of the computers and, network devices are interconnected with one another,, allowing for most transmissions to be distributed, even, if one of the connections go down. This topology is not, commonly used for most computer networks as it is, difficult and expensive to have redundant connection to, every computer. However, this topology is commonly, used for wireless networks (Fig 10)., , •, , •, , Data can be transmitted from different devices, simultaneously. This topology can with stand high, traffic., Even if one of the components fails there is always, an alternative present. So data transfer doesn't get, affected., Expansion and modification in topology can be done, without disrupting other nodes., , 1 Physical cable or transmission media., 2 Number of bits transmitted on the media., 3 When to transmit the data on the network., 4 Volume of data to be transmitted., 5 Interact with a network with different cable type or topology., 6 Ensure that the message has been delivered intact, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 175
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Star Bus, Each computer connects to a, central connection device., , All information passes, through the, central network connection., , Each computer must be, close to the, central device., 100 meters, maximum, cable length., , Add a new, computer by, plugging in a, new cable, from, the, computer to, the connection device., , When one computer goes down,, the rest of the network is unaffected. If the connection device, goes down, then, the network is, down., , More expensive, of, the, simple topologies,, it requires, costly, connection dev i c e ., Usually, cheaper, than a hybrid network., , Uses twisted, pair cable., , To add a, c o m p u t e r,, you, must, shut down, the network, and disconnect, the, cable from, the existing, computers., , If one computer, malfunctions, the, entire network, goes down., , A cheaper, network, s i n c e, there is, usually, one continuous, copper, cable., , Single continuous cable connects the devices., , Cable between the, computers, must be broken to add a, new computer, so the, network is, down until, the new device is back, online., , If there's a break, in the cable or an, error in the network, information, continues to transfer through the, rest of the ring until reaching the, point of the break., This, makes, troubleshooting, easy., , Up to 24, computers, per network., , Requires large, amounts, of, cable. No more, than, 100, meters from, the computer to, the connection, device., , Bus, Single, cable connects everything., , One, computer at a time, sends information. Information goes, along, the, cable and the, computer accesses the information off, the cable., , Connect the, cable from, one, computer to the, next and so, on to the end., , Information, goes in one, direction, around the, ring, and, passes along, the ring until it, reaches the, correct computer., , Computers, are located, close to each, other., , A terminator, is placed at, each end of, the network., , Terminator is, required, at, each end of the, cable., Uses coaxial or, twisted pair cabling., , Ring, S i n g l e, cable configured in a, ring., , 176, , Setup, is, easy. There, is no connector., The ring has, no beginning, and no end., , One of the, more expensive, topologies, due, to, high cable, costs., , Requires more, cabling than, other topologies., Uses twisted, pair., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Hybrid, Mesh, Combines, two or more, different, structures., , Often used, across long, distances. Information, transfer can, happen in different ways,, depending on, the other topologies., , Often created, when, expanding an, existing network. Can, use a variety, of connection, devices., , Connection, devices, make combining different networks, and different, topologies, easy., , and in a proper manner., List of Network Protocols, 1 TCP/IP: Transmission Control Protocol / Internet Protocol is an industry standard protocol widely used. It is, used for inter operating among different types of computers. Almost all types of networks support TCP/IP. It is, the protocol used by the Internet. It uses a 32 - bit addressing scheme., IP Address, IP defines an addressing scheme that is independent of, the underlying physical address (e.g. 48-bit MAC address). IP specifies a unique 32-bit number for each host, on a network., , Troubleshooting is, most difficult in, this topology because of the variety of technologies., , Expens i v e ,, large,, and usually complicated., , Cabling depends on the, types of networks., Can use twisted, pair and coaxial, cable., Also incorporates fiber optic, cabling over, long distances., , FTP is built on a client-server architecture and uses separate control and data connections between the client and, the server. FTP users may authenticate themselves using, a clear-text sign-in protocol, normally in the form of a, username and password, but can connect anonymously, if the server is configured to allow it., For secure transmission that hides (encrypts) the, username and password, and encrypts the content, FTP, is often secured with SSL/TLS ("FTPS"). SSH File Transfer Protocol (SFTP) is sometimes also used instead., 4 SMTP, Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across, Internet Protocol (IP) networks., , This number is known as the Internet Protocol Address,, the IP Address or the Internet Address. These terms are, interchangeable. Each packet sent across the internet, contains the IP address of the source of the packet and, the IP address of its destination., , While electronic mail servers and other mail transfer, agents use SMTP to send and receive mail messages,, user-level client mail applications typically only use, SMTP for sending messages to a mail server for relaying., , 2 UDP - User Datagram Protocol - is a simple OSI transport layer protocol for client/server network applications, based on Internet Protocol (IP). UDP is the main alternative to TCP and one of the oldest network protocols in, existence, introduced in 1980. UDP is often used in, videoconferencing applications or computer games specially tuned for real-time performance., , For receiving messages, client applications usually use, either the Post Office Protocol (POP) or the Internet, Message Access Protocol (IMAP) or a proprietary system (such as Microsoft Exchange or Lotus Notes/, Domino) to access their mail box accounts on a mail, server., 5 Telnet, , 3 FTP: File Transfer Protocol (FTP) is a standard network protocol used to transfer files from one host or to, another host over a TCP-based network, such as the, Internet., , Telnet is a network protocol used on the Internet or local, area networks to provide a bidirectional interactive textoriented communication facility using a virtual terminal, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 177
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connection. User data is interspersed in-band with Telnet, control information in an 8-bitbyte oriented data connection over the Transmission Control Protocol (TCP)., Telnet provided access to a command-line interface (usually, of an operating system) on a remote host. Most, network equipment and operating systems with a TCP/, IP stack support a Telnet service for remote configuration (including systems based on Windows NT). Because, of security issues with Telnet, its use for this purpose, has waned in favour of SSH., 6 HTTP, , Networking Components, •, , Gateway: A device sitting at a network node for, interfacing with another network that uses different, protocols. Works on OSI layers 4 to 7., , •, , Router: A specialized network device that determines, the next network point to which it can forward a data, packet towards the destination of the packet. Unlike, a gateway, it cannot interface different protocols., Works on OSI layer 3., , •, , Switch: A device that allocates traffic from one, network segment to certain lines (intended, destination(s)) which connect the segment to another, network segment. So unlike a hub a switch splits the, network traffic and sends it to different destinations, rather than to all systems on the network. Works on, OSI layer 2., , •, , Bridge: A device that connects multiple network, segments along the data link layer. Works on OSI, layer 2., , •, , Hub: It connects multiple Ethernet segments together, making them act as a single segment. When using a, hub, every attached device shares the same, broadcast domain and the same collision domain., Therefore, only one computer connected to the hub, is able to transmit at a time., , The Hypertext Transfer Protocol (HTTP) is an application, protocol for distributed, collaborative, hypermedia, information systems. HTTP is the foundation of data, communication for the World Wide Web., Hypertext is a multi-linear set of objects, building a, network by using logical links (the so-called hyperlinks), between the nodes (e.g. text or words). HTTP is the, protocol to exchange or transfer hypertext., 7 SSH File Transfer Protocol, In computing, the SSH File Transfer Protocol (also, Secure File Transfer Protocol, Secure FTP, or SFTP) is, a network protocol that provides file access, file transfer,, and file management functionalities over any reliable, data stream., , Depending on the network topology, the hub provides, a basic level 1 OSI model connection among the, network objects (workstations, servers, etc.). It, provides bandwidth which is shared among all the, objects, compared to switches, which provide a, connection between individual nodes., , It was designed by the Internet Engineering Task Force, (IETF) as an extension of the Secure Shell Protocol, (SSH) version 2.0 to provide secure file transfer, capability, but is also intended to be usable with other, protocols., The IETF of the Internet Draft states that even though, this protocol is described in the context of the SSH-2, protocol, it could be used in a number of different, applications, such as secure file transfer over Transport, Layer Security (TLS) and transfer of management, information in VPN applications., This protocol assumes that it is run over a secure, channel, such as SSH, that the server has already, authenticated the client, and that the identity of the client, user is available to the protocol., 8 Post Office Protocol, In computing, the Post Office Protocol (POP) is an, application-layer Internet standard protocol used by local, e-mail clients to retrieve e-mail from a remote server, over a TCP/IP connection. POP and IMAP (Internet, Message Access Protocol) are the two most prevalent, Internet standard protocols for e-mail retrieval., Virtually all modern e-mail clients and servers support, both. The POP protocol has been developed through, several versions, with version 3 (POP3) being the current, standard. Most webmail service providers such as, Hotmail, Gmail and Yahoo! Mail also provide IMAP and, POP3 service., , 178, , •, , Repeater: A device to amplify or regenerate digital, signals received while sending them from one part of, a network into another. Works on OSI layer 1., , •, , Modem (MoDem): A device that modulates an analog, "carrier" signal (such as sound), to encode digital, information, and that also demodulates such a carrier, signal to decode the transmitted information, as a, computer communicating with another computer over, the telephone network, , Types of MODEM, External Modem: This is a modem separated from the, system unit in the computer case. It is connected to the, serial port of the computer by means of a cable. It is, connected to the telephone wall jack by another cable., Internal Modem: An internal modem is a circuit board, (a modem card) that can be added to the system unit of, the computer. It takes one of the expansion slots., Wired Modem / Standard Modem, Most modem’s used today are called standard modems., These modems are usually operated by commands, entered from a microcomputer keyboard. Users control, the functions (dialling, etc.) of a modem through the, keyboard. Modems may use different command, languages to control their functions,, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Wireless Modems: Wireless modems transmit the data, signals through the air instead of by using a cable. They, sometimes are called a radiofrequency modem. This type, of modem is designed to work with cellular technology,, and wireless local area networks. Wireless modems are, not yet perfected, but the technology is rapidly improving., ADSL Modem, Asymmetric Digital Subscriber Line, ADSL (Fig 11) is a, type of DSL broadband communications technology used, for connecting to the Internet. ADSL allows more data to, be sent over existing copper telephone lines POTS, when, compared to traditional modem lines. A special filter, called, a micro filter, is installed on a subscriber's telephone line, to allow both ADSL and regular voice (telephone) services, to be used at the same time. ADSL requires a special, ADSL modem and subscribers must be in close, geographical locations to the provider's central office to, receive ADSL service. Typically this distance is within a, radius of 2 to 2.5 miles. ADSL supports data rates of from, 1.5 to 9 Mbps when receiving data (known as the downstream rate) and from 16 to 640 Kbps when sending data, (known as the up- stream rate)., , Ethernet NICs plug into the system bus of the PC and, include jacks for network cables, while WI-FI NICs contain built-in transmitters / receivers (transceivers). In new, computers, many NICs are now pre-installed by the manufacturer. All NICs feature a speed rating such as 11 Mbps,, 54 Mbps or 100 Mbps that suggest the general performance of the unit., Network Cables Standards, Cable is the medium through which information usually, moves from one network device to another. There are, several types of cable which are commonly used with, LANS. In some cases, a network will utilize only one, type of cable, other networks will use a variety of cable, types. The type of cable chosen for a network is related, to the network's topology, protocol, and size. Understanding the characteristics of different types of cable and, how they relate to other aspects of a network is necessary for the development of a successful network., Cable standards, A wide range of cabling types are been used to run Ethernet, systems. Therefore, different types of cabling standards, are being used for the networks involved in connecting, devices together using different types of cabling system., , Network Interface Card (NIC), NIC (Fig. 12) provides the hardware interface between a, computer and a network. A NIC technically is network, adapter hardware in the form factor of an add-in card such, as a PCI or PCMCIA card. Some NIC cards work with, wired connections while others are wireless. Most NICs, support either wired Ethernet or WI-FI wireless standards., 12, , Coaxial cable (Fig 13) is the kind of copper cable used by, companies between the community antenna and user, homes and businesses. Coaxial cable is sometimes used, by telephone companies from their central office to the, telephone poles near users. It is also widely installed for, use in business and corporation and other types of., Coaxial cable is called "coaxial" because it includes one, physical that carries the signal surrounded (after a layer, of insulation) by another concentric physical channel,, both running along the same axis. The outer channel, serves as a ground. Many of these cables or pairs of, coaxial tubes can be placed in a single outer sheathing, and, with repeaters, can carry information for a great distance., 10BASE-T Cable Standard: 10Base-T is one of the, Ethernet standards for cabling in a network environment., 10BaseT uses a twisted pair cable with a maximum length, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 179
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of 100 meters. Standard 10BaseT operates at 10 Mbps. It, is commonly used in a star topology., 10BASE-FL Cable Standard: 10BaseFL is a fibber optic, cable standard designed to run at 10 Mbps. It is similar, to 10Base-T, though the media type is fibber. For use up, to 2000 meters., 100BASE-TX Cable Standard: 100 Mbps Fast Ethernet, over category 5 twisted pair cable. Maximum cable length, of 100 meters., 100BASE-FX Cable Standard: 100 Mbps Fast Ethernet, standard over fibber cable. Can transmit data up to 2000, meters., 1000BASE-T Cable Standard: Gigabit Ethernet over, twisted pair copper wires. Transmit up to 1000 Mbps., 100 meter maximum cable length. Cat5 or better required, (Cat6 cabling recommended)., 1000BASE-CX Cable Standard: Gigabit Ethernet over, a special copper twinax cable. Up to 25 meters in length., Typically used in a wiring closet or data center as a short, jumper cable., , adjoining wires., The advantage of using twisted pair cables are, •, , It is lighter, thinner and more flexible, , •, , Easy to install, , •, , It is in expensive, , There are two varieties of twisted pair cabling, they are, •, , Unshielded Twisted Pair (UTP), , •, , Shielded Twisted Pair (STP), , Unshielded twisted pair (UTP), Unshielded twisted pair (Fig 14) cabling consists of two, unshielded wires twisted around each other that contain, no shielding. It is commonly used in the telephone wires, and is common for computer networking because of high, flexibility of the cables. It is a plastic connector that looks, like a large telephone-style connector. The standard connector for unshielded twisted pair cabling is RJ-45 connector., , 1000BASE-SX Cable Standard: Gigabit Ethernet using, a short-wavelength laser device over multimode fibber, optic cable. 50 μm core (max 300 meters) or 62.5 μm, core (max 500 meters). 1000Mbps maximum transfer, speed., 1000BASE-LX Cable Standard: Gigabit Ethernet using, long-wavelength laser transmitters over fibber optic, cable. Up to 3,000 meters. Uses single mode fibber and, requires SC connectors for terminating the cable., 10 GBASE-SR Cable Standard: 802.3ae standard. 33, meters for 62.5μm fibber optic cable, 300 meters for, 50μm cables. 10 Gbps (Gigabit per second) transfer rate., 10 GBASE-LR Standard: 10 Gbps transfer rate. 10, kilometres maximum distance. Fibber optic cable., , UTP has five categories of cable standards defined by the, Electronic Industries Association and Telecommunications, Industry Association (commonly known as EIA/TIA). The, five categories of unshielded twisted pair are:, Categories of Unshielded Twisted Pair, , 10 GBASE-ER Standard: 10 Gbps transfer rate. 40, kilometres maximum cable length. Fibber optic cable., , In order to manage the network cabling, you need to be, familiar with the standards that may be used on modern, networks. The categories of the unshielded twisted pair, cable are described below., , Media types, , Category 1, , A cable is a device which contains a number of signal, conductors usually in the form of separate wires. It is the, medium through which information usually moves from, one system to another through the network. There are, several types of cable which are commonly used with, the local area network. In some cases, a network utilizes, only one types of cable, whereas other network uses a, variety of cable types. The type of cable chosen for a, network is related to network topology, protocol and size., , •, , It is a form of UTP that contains two pairs of wire., , •, , CAT is suitable for voice communications but not for, data., , •, , It can carry up to 128 kilobits per second (Kbps) of, data., , •, , Twisted Pair, , It is usually used for telephone wire Data rate - 1, Mbps. This type of wire is not capable of supporting, computer network traffic and is not twisted., , Category 2, , Twisted pair cable is the most common type of network, medium used in LAN today. A transmission media consist, of colour coded pairs of two shielded insulated copper, wires which are arranged in a spiral pattern. The spiral, pattern is an important aspect of twisted - pair cables in, order to minimize cross talk of interference between, , 180, , •, , It contains four wire pairs and can carry up to 4 Mbps, of data., , •, , CAT 2 is rarely found on modern networks., , •, , Category 2 or CAT 2 is capable of transmitting data, up to 4 Mbps. This of cable is seldom used., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Category 3, •, , CAT 3 made up of four twisted - pair wires, each twist, is three times per foot. It is certified to transmit data, up to 10 Mbps., , •, , CAT 3 has typically been used for 10 Mbps Ethernet, or 4 Mbps Token Ring networks., , •, , The CAT 3 cabling is gradually replaced with CAT5 to, accommodate higher throughput., , Category 4, •, , CAT 4 is made up of four twisted-pair wires, specialized to transmit data up to 16 Mbps and is rarely is, used in new installations., , •, , CAT 4 may be used for 16Mbps Token Ring or 10, Mbps Ethernet networks. It is guaranteed for signals, as high as 20 MHz and Provides More protection, against crosstalk and attenuation than CAT1, CAT2,, orCAT 3., , The extra covering in shielded twisted pair wiring protects, the transmission line from leaking into or out of the cable., STP cabling often is used in networks, especially fast, data rate Ethernets., Fiber Optic Cable (Fig 16), , Category 5, •, , CAT 5 is the most popular twisted pair Ethernet cabling designed for high signal integrity which is in common use today., , •, , CAT 5 contains four wire pairs and supports up to, 100 Mbps throughout., , •, , It is the most popular form of UTP for new network, installations and upgrades to Fast Ethernet., , •, , In addition to 100 Mbps Ethernet, CAT 5 wiring can, support other fast networking technologies., , •, , It is popular because it is both affordable and high, speed for today's local area networks Cat 5 cables, are often used in structured cabling for computer, networks such as fast Ethernet., , Category 6, •, , •, , •, , •, , A technology that uses glass (or plastic) threads (fibers), to transmit. A fiber optic cable consists of a bundle of, glass threads, each of which is capable of transmitting, messages on to light waves., Fibre optics has several advantages over traditional metal, lines:, •, , CAT 6 cable was originally designed to support gigabit Ethernet. It is similar to CAT 5 wire, but contains a, physical separator between the four, , Fibre optic cables have a much greater than metal, cables. This means that they can carry more data., , •, , Fibre optic cables are less susceptible than metal, cables to interference., , Twisted copper wires pairs to further reduce the electromagnetic interference., , •, , Fibre optic cables are much thinner and lighter than, metal wires., , It is a twisted-pair cable that contains four wire pairs,, each wrapped in foil insulation. Additional foil insulation covers the bundle of wire pairs, and a fire-resistant plastic sheet covers the second foil layer., , •, , Data can be transmitted (the natural form for data), rather than analogically., , The foil insulation provides excellent resistance to, crosstalk and enables CAT 6 to support at least six, times the throughput supported by regular CAT 5., When the CAT 6 is used as a patch cable, it is usually, terminated in RJ-45 Electrical connectors., , Shield Twisted Pair (Fig 15), A type of copper telephone wiring in which each of the two, copper wires that are twisted together are coated with an, insulating coating that functions as a ground for the wires., , The main disadvantage of fibre optics is that the cables, are expensive to install. In addition, they are more fragile, than wire and are difficult to splice., In addition, telephone companies are steadily replacing, traditional telephone lines with fibre optic cables. In the, future, almost all communications will employ fibre optics., Straight Cable, A straight cable (Fig 17) is to connect different type of, devices. This type of cable will be used most of the time, and can be used to:, , IT & ITES : COPA - (NSQF Level - 4)- Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 181
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Rollover Cable (Fig 19), 19, , 1 Connect a computer to a switch/hub's normal port., 2 Connect a computer to a cable/DSL modem's LAN, port., 3 Connect a router's WAN port to a cable/DSL modem's, LAN port., 4 Connect a router's LAN port to a switch/hub's uplink, port. (Normally used for expanding network), 5 Connect 2 switches/hubs with one of the switch/hub, using an uplink port and the other one using normal, port., If you need to check how straight cable looks like, it's, easy. Both sides (side A and side B) of cable have wire, arrangement with same colour., Crossover Cable, A crossover cable (Fig 18), it's usually used to connect, same type of devices. A crossover cable can be used to:, , 1 Connect 2 computers directly., 2 Connect a router's LAN port to a switch/hub's normal, port. (Normally used for expanding network)., 3 Connect 2 switches/hubs by using normal port in both, switches/hubs., In you need to check how crossover cable looks like,, both side (side A and side B) of cable have wire arrangement with following different colour., , 182, , Rollover cable (also known as Cisco Console Cable or a, Yost Cable) is a type of cable that is often used to connect a computer terminal to a router's port. This cable is, typically flat (and has a light blue colour) to help distinguish it from other types of network cabling. It gets the, name rollover because the pin outs on one end are reversed from the other, as if the wire had been rolled over, and you were viewing it from the other side., Connectors, The media connectors are the physical devices that help, to transfer the data between the systems., RJ11: Registered Jack-11 (Fig 20) a four- or six-wire, used primarily to connect telephone equipment. RJ-11, connectors are also used to connect some types of some, types of Local area network., 20, , RJ45: RJ45 (Fig 21) connectors feature eight pins to which, the wire strands of a cable interface electrically. Standard, RJ-45 pinouts define the arrangement of the individual wires, needed when attaching connectors to a cable., ST: ST stands for Straight Tip (Fig 22) - a quick release, bayonet style developed by AT&T. STs were predominant, in the late 80s and early 90s., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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21, , ST Connectors are among the most commonly used fiber, optic connectors in networking applications. They are cylindrical with twist lock coupling, 2.5mm keyed ferrule. ST, connectors are used both short distance applications and, long line systems., SC: SC stands for Subscriber Connector (Fig 23) - a, general purpose push/pull style Connector developed by, NTT. SC has an advantage in keyed duplexibility to support send/receive channels., SC Connectors are frequently used for newer Network, applications. The SC is a snap-in connector that is widely, used in single mode systems for its performance. The, SC connector is also available in a Duplex configuration., They offer low cost, simplicity, and durability. SC connectors provide for accurate alignment via their ceramic ferrules., The square, snap-in connector latches with a simple, push-pull motion and is keyed. They feature a 2.5mm, Ferrule and molded housing for protection. Typical matched, SC connectors are rated for 1000 mating cycles and have, an Insertion Loss of 0.25 dB., , USB: The USB 2.0 Standard-A type of USB plug is a, flattened rectangle which inserts into a "downstream-port", receptacle on the USB host, or a hub, and carries both, power and data. This plug is frequently seen on cables, that are permanently attached to a device, such as one, connecting a keyboard or mouse to the computer via, USB connection., A Standard-B plug-which has a square shape with bevelled exterior corners-typically plugs into an "upstream, receptacle" on a device that uses a removable cable,, e.g. a printer. A Type B plug delivers power in addition to, carrying data. On some devices, the Type B receptacle, has no data connections, being used solely for accepting, power from the upstream device. This two-connector-type, scheme (A/B) prevents a user from accidentally creating, an Electrical loop., BNC: Bayonet Neill Concelman (Fig 25) connector,, (sometimes erroneously called a British Naval Connector, or Bayonet Nut Connector, a type of connector used with, coaxial cable such as the RG-58 A/U cable used with the, 10Base2. The basic BNC connector is a male type, mounted at each end of a cable., , LC: LC stands for Lucent Connector (Fig 24). The LC is, a small form factor fiber optic connector., The LC Connector uses a 1.25 mm ferrule, half the size of, the ST. Otherwise, it is a standard ceramic Ferrule connector. The LC has good performance and is highly favoured, for single mode., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 183
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This connector has a center pin connected to the center, cable conductor and a metal tube connected to the outer, cable shield. A rotating ring outside the tube locks the, cable to any female connector., BNC T-connectors (used with the 10Base-2 system) are, female devices for connecting two cables to a NIC. A, BNC barrel connector allows connecting two cables together., BNC connectors can also be used to connect some, monitor, which increases the accuracy of the signals sent, from the adapter., Crimping Tool: A crimping tool (Fig 26) is a tool designed to crimp or connect a connector to the end of a, cable. For example, network cables and phone cables, are created using a crimping tool to connect the RJ45 and, RJ11 connectors to the end of the cable. In the picture to, the right, is an example of what a crimping tool looks like., This shows a tool capable of crimping both RJ-11 and RJ45 connectors., , 5 Arrange the untwisted wires in a row, placing them, into the position, running from right to left, in which, they will go into the RJ-45 connector:, •, , Orange with a white stripe, , •, , Orange, , •, , Green with a white stripe, , •, , Blue, , •, , Blue with a white strip, , •, , Green, , •, , Brown with a white stripe, , •, , Brown, , 6 Trim the untwisted wires to a suitable length by holding the RJ-45 connector next to the wires. The insulation on the cable should be just inside the bottom, of the RJ-45 connector. The wires should be trimmed, so that they line up evenly with the top of the RJ-45, connector., •, , Trim the wires in small increments, checking frequently to ensure a correct fit. It's better to cut the, untwisted wires a few times than have to go back, and start all over again because you trimmed off, too much., , 7 Insert the wires into the RJ-45 connector, making sure, that they stay aligned and each color goes into its, appropriate channel. Make sure that each wire goes, all the way to the top of the RJ-45 connector. If you, don't make these checks, you will find that your newly, crimped RJ-45 connector is useless., 8 Use the crimping tool to crimp the RJ-45 connector, to the cable by pressing the jacket and cable into the, connector so that the wedge at the bottom of the connector is pressed into the jacket., Re crimp the cable once more to ensure proper connection., , How to Crimp RJ45, 1 Strip 1 to 2 inches (2.5 to 5.1 cm) of the outer skin at, the end of the cable wire by making a shallow cut in, the skin with a utility knife. Run the knife around the, cable, and the jacket should slide off easily. There will, be 4 pairs of twisted wires exposed, each of them a, different color or colour combination., Orange-white striped and solid orange, Green-white striped and solid green, Blue-white striped and solid blue, Brown-white striped and solid brown, 2 Fold each pair of wires backwards to expose the core, of the cable., 3 Cut off the core and discard., , 9 Follow the instructions above to crimp an RJ-45 connector to the opposite end of the cable, 10 Use a cable tester to assure that your cable is working properly when both ends are crimped., Cable Tester (Fig 27), When connected to an Ethernet cable, a network cable, tester tells if the cable is capable of carrying an Ethernet, signal. If the cable carries the signal, this indicates that, all the circuits are closed, meaning that electric current, can move unimpeded through the wires, and that there, are no short circuits, or unwanted connections, in the wire., Network cable testers vary in complexity and price, but a, basic tester consists of a source of electrical current, a, measuring device that shows if the cable is good, and a, connection between the two, usually the cable itself., , 4 Straighten the twisted wires using 2 pair of tweezers., Grasp a wire beneath a bend with 1 pair of tweezers,, and use the other pair to gently straighten the bend., The straighter your wires, the easier your job will be, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, 184, , Copyright @ NIMI Not to be Republished
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Switch, A Network Switch (Fig 28) is a small hardware device, that joins multiple computers together within one Local, Area Network. Technically, network switches operate at, layer two (Data Link Layer) of the OSI., 28, , Computer networks use Ethernet cables to allow computers in the network to "talk" to each other. An Ethernet, cable has eight wires that are arranged in four pairs. For, current to flow correctly, the wire pairs must be connected, in the proper order., A network cable tester can identify if the wires are paired, correctly. It can also show if there is a break in the insulation, a situation which allows crosstalk between two, wires that should not be connected. The tester can also, tell whether the cable has the proper level of resistance., A network cable tester can be a simple apparatus that, merely identifies whether current flows through the cable,, or it may be a professional-level, complex device that, gives additional information that helps identify the problem., Professional-level network cable testers may not only, tell if an open circuit exists, but may identify where the, break is located. Some also identify the gauge of wire, used and can generate their own signal to test for interference., How to Check with the Tester, , Network switches appear nearly identical to hub, but a, switch generally contains more intelligence (and a slightly, higher price tag) than a hub. Unlike hubs, network switches, are capable of inspecting data packet as they are received,, determining the source and destination device of each, packet, and forwarding them appropriately., By delivering messages only to the connected device intended, a network switch conserves bandwidth and offers, generally better performance than a hub., Availability of Switches, 1 8 Port Switches, 2 16 port switches, 3 24 port switches, 4 32 port switches, Hub: A Hub (Fig 29) is a small, simple, inexpensive, device that joins multiple computers together. Many, network hubs available today support the Ethernet, standard. Other types including USB hubs also exist, but, Ethernet is the type traditionally used in home networking., To network a group of computers using an Ethernet hub,, 29, , 1 Turn on your network cable tester., 2 Plug one end of the Ethernet cable you are trying to, test into the "IN" Ethernet input on the network cable, tester., 3 Plug the other end of your Ethernet cable you are, trying to test into the "OUT" input on the network cable, tester., 4 Press the "Test" button. The network cable tester will, send a signal across the Ethernet cable. If the signal, gets from one end of the cable to the other, a green, light will appear on the device, letting you know that, the test was successful. If the signal does not get, from one end of the cable to the other, a red light will, appear on the device, letting you know that the test, was not successful and that the cable is bad., , first connect an Ethernet cable into the unit, and then, connect the other end of the cable to each computer's, NIC. All Ethernet hubs accept the RJ45 connectors of standard Ethernet cables., Ethernet hubs vary in the speed (network data rate or, bandwidth they support. Some years ago, Ethernet hubs, offered only 10 Kbps rated speeds. Newer types of hubs, offer 100 Mbps Ethernet. Some support both 10 Mbps, and 100 Mbps (so-called dual-speed or 10/100 hubs)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 185
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Routers, Routers (Fig 30) are physical devices that join multiple, wired or wireless networks together. Technically, a wired, or wireless router is a Layer 3 gateway, meaning that the, wired/wireless router connects networks (as gateways do),, and that the router operates at the network layer of the, OSI model., , monthly fee for this equipment that is added to your ISP, account billing., In addition to serving individuals, ISPs also serve large, companies, providing a direct connection from the, company's networks to the Internet. ISPs themselves, are connected to one another through Network Access, Point (NAPs). ISPs may also be called IAPs (Internet, Access Provider)., State Owned ISP's, •, , BSNL - Servicing all of India except Mumbai and, Delhi. Triple-play Broadband Services provided by, ADSL and VDSL. Also providing internet services over, GPRS, 3G, as well as WiMax, , •, , MTNL - Servicing Mumbai and Delhi. Triple-play, Broadband Services provided by ADSL under the "TriBand" brand. Also providing GPRS and 3G internet, services., , Private Owned nationwide ISP's, •, , Airtel - ADSL, GPRS, 3G & 4G LTE, , Home networkers often use an Internet Protocol (IP), wired or wireless router, IP being the most common OSI, network layer protocol. An IP router such as a DSL or, cable modem router joins the home's LAN to the WAN, of the Internet., , •, , Skynet Broadband - Internet Service Provider, , •, , Aircel - GPRS & 3G, , •, , Hathway - Broadband over Cable, , •, , Idea - GPRS & 3G, , Bridges, , •, , MTS India - CDMA/EV-DO, , A bridge (Fig 31) device filters data traffic at a network, boundary. Bridges reduce the amount of traffic on a LAN, by dividing it into two segments., , •, , O-Zone Networks Private Limited - Pan - India Public Wi-Fi hotspot provider, , •, , Reliance Communications - ADSL, GPRS & 3G,, Metro-Ethernet, CDMA/EV-DO, Wimax, , •, , Reliance Industries - LTE (to be launched), , •, , Sify - Broadband over cable, , •, , Tata DoCoMo - GPRS & 3G, , •, , Tata Indicom - ADSL, CDMA/EV-DO, Metro-Ethernet,, WiMax, , •, , Vodafone - GPRS & 3G, , 31, , Bridges operate at the data link layer (Layer 2) of the OSI, model. Bridges inspect incoming traffic and decide whether, to forward or discard it. An Ethernet bridge, for example,, inspects each incoming Ethernet frame - including the, source and destination MAC addresses, and sometimes, the frame size - in making individual forwarding decisions., ISP: Internet Service Provider, it refers to a company that, provides Internet services, including personal and business access to the internet. For a monthly fee, the service provider usually provides a software package,, Username, password and access phone number., Equipped with a modem you can then log on to the, Internet and browse the world wide web and USENET, and send and receive email For broadband access you, typically receive the broadband modem hardware or pay a, , 186, , NSP: Network Service Providers (NSP) is a business or, organization that sells bandwidth or network access by, providing direct Internet backbone access to the Internet, and usually access to its Network Access Point (NAPs)., Network service providers may consist of Telecommunications companies, data carriers, wireless communications providers, Internet service provider, and Cable television operators offering high-speed Internet access., Dial up: Dial-up access is really just like a phone connection, except that the parties at the two ends are computer devices rather than people. Because dial-up access, uses normal telephone lines, the quality of the connection, is not always good and data rate are limited., In the past, the maximum data rate with dial-up access, was 56 Kbps (56,000 bits per second), but new technologies such as ISDN are providing faster rates., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Broadband: The term broadband refers to a telecommunications signal or device of greater Bandwidth (signal processing), in some sense, than another standard or usual, signal or device (and the broader the band, the greater the, capacity for traffic)., Wireless (Wi-Fi): Wireless broadband is high-speed, Internet service via wireless technology. Wireless broadband is available in Internet cafés, local "hot spots" within, many cities, private businesses and many homes., The advantage of wireless broadband is that the computer receiving the Internet signal need not be tethered, by an Ethernet or network cable to the broadband modem or router., , A wireless broadband modem receives the service and, transmits it via radio waves to the immediate surrounding area. Any computer equipped with wireless capacity, within receiving distance can pick up the signal, making, the Internet 'portable.' The most common way to take, advantage of wireless broadband is by using a laptop, computer., Mobile Broadband: The term mobile broadband refers, to high-speed wireless Internet connections and services, designed to be used from arbitrary locations., Cellular networks normally provide broadband connections suitable for mobile access. The technologies in use, today fall into two categories -3G (third generation cell, networks) and 4G (fourth generation)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 187
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.70, , Introduction to TCP/IP, Objectives : At the end of this lesson you shall be able to, • explain TCP/IP, addresses and subnets., Introduction to TCP/IP : TCP and IP were developed by, Department of Defense (DOD) research project to connect, a number different networks designed by different vendors, into a network of networks (the “Internet”). It was initially, usccessful because it delivered a few basic services that, everyone needs (file transfer, electronic mail, remote, logon) across a very large number of client and server, systems. Several computers in a small department can, use TCP/IP (along with other protocols) on a single LAN., The IP component provides routing from the department, to the enterprise network, then to regional networks, and, finally to the global internet. On the battlefield a, communications network will sustain damage, so the, DOD designed TCP/IP to be robust and automatically, recover from any node or phone failure. This design, allows the construction of very large networks with less, central management. However, because of the automatic, recovery, network problems can go undiagnosed and, uncorrected for long periods of time., As with all other communications protocol, TCP/IP is, composed of layers:, IP is responsible for moving packet of data from node to, node. IP forwards each packet based on a four byte, destination address (the IP number). The Internet, authorities assign ranges of numbers to different, organisations. The organisations assign groups of their, numbers to departments. IP operates on gateway, machines that move data from department to organisation, to region and then around the world., TCP is responsible for verifying the correct delivery of, data from client to server. Data can be lost in the, intermediate network. TCP adds support to detect errors, or lost data and to trigger retransmission until the data is, correctly and completely received., Sockets is a name given to the package of subroutines, that provide access to TCP/IP on most systems., The Internet Protocol was developed to create a Network, of Networks (the “Internet”). Individual machines are first, connected to a LAN (Ethernet or Token Ring). TCP/IP, shares the LAN with other users (a Novell file server,, Windows for Workgroups peer systems). One device, provides the TCP/IP connection between the LAN and, the rest of the world. (Refer Fig 1), To insure that all types of systems from all vendors can, communicate, TCP/IP is absolutely standardised on the, LAN. However, larger networks based on long distances, and phone lines are more volatile. In US, many large, corporations would wish to reuse large internal networks, based on IBM’s SNA. In Europe, the national phone, 188, , companies traditionally standardize on X.25. However,, the sudden explosion of high speed microprocessors,, fiber optics and digital phone systems has created a burst, of new options: ISDN, frame relay, FDDI, Asynchronous, Transfer Mode (ATM). New technologies arise and, become obsolete within a few years. With cable TV and, phone companies competing to built the National, Information Superhighway, no single standard can govern, citywide, nationwide, or worldwide communications., The original design of TCP/IP as a Network of Networks, fits nicely within the current technological uncertainty., TCP/IP data can be sent across a LAN or it can be carried, within an internal corporate SNA network or it can, piggyback on the cable TV service. Furthermore,, machines connected to any of these networks can, communicate to any other network through gateways, supplied by the network vendor., Addresses : Each technology has its own convention for, transmission messages between two machines within, the same network. On a LAN, messages are sent between, machines by supplying the six byte unique identifier (the, “MAC” address). In an SNA network, every mahine has, Logical Units with their own network address. DECNET,, Appletalk and Novell IPX all have a scheme for assigning, numbers to each local network and to each workstation, attached to the network., On top of these local or vendor specific network addresses,, TCP/IP assigns a unique number to every workstation in, the world. This “IP number” is a four byte value that, by, convention, is expressed by converting each byte into a, decimal number (0 to 255) and separating the bytes with, a period. For example, a server IP is like 130.132.59.234, Subnets: Although the individual subscribers do not, need to tabulate network numbers or provide explicit, routing, it is convenient for most Class B networks to be, internally manage as much smaller and simpler version, , Copyright @ NIMI Not to be Republished
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of the larger network organisations. It is common to, subdivide the two bytes available for internal assignment, into a one byte department number and a one byte, workstation ID. (Refer Fig 2), , There are three levels of TCP/IP knowledge. Those who, administer a regional or national network must design a, system of long distance phone lines, dedicated routing, devices and very large configuration files. They must, know the IP numbers and physical locations of thousands, of subscriber networks. They must also have a formal, network monitor strategy to detect problems and respond, quickly., Each large company or university that subscribes to the, Internet must have an intermediate level of network, organisation and expertise. A half dozen routers might be, configured to connect several dozen departmental LANs, in several buildings. All traffic outside the organisation, would typically be routed to a single connection to a, regional network provider., However, the end user can install TCP/IP on a personal, computer without any knowledge of either the corporate, or regional network. Three pieces of information are, required:, , The enterprise network is built using commercially, available TCP/IP router boxes. Each router has small, tables with 255 entries to translate the one byte department, number into selection of a destination Ethernet connected, to one of the routers., TCP treats the data as a stream of bytes. It logically, assigns a sequence number to each byte. The TCP, packet has a header that says, in effect, “This packet, starts with byte 379642 and contains 200 bytes of data.”, The receiver can detect missing or incorrectly sequenced, packets. TCP acknowledges data that has been received, and retransmits data that has been lost. The TCP design, means that error recovery is done end-to-end between, the Client and Server machine. There is no formal, standard for tracking problems in the middle of the, network, though each network has adopted some adhoc, tools., , 1 The IP address assigned to this personal computer., 2 The part of the IP address (the subnet mask) that, distinguishes other machines on the same LAN, (messages can be sent to them directly) from machines, in other departments or elsewhere in the world (which, are sent to a router machine), 3 The IP address of the router machine that connects, this LAN to the rest of the world., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.70, , Copyright @ NIMI Not to be Republished, , 189
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IT & ITES, Related Theory for Exercise 1.10.71 to 1.10.72, COPA - Networking Concepts, Transmission media and network components, Objectives :At the end of this lesson you shall be able to, • explain cable media, wireless media and network adapter., Network media : Media are what the message is, transmitted over. Different media have different properties, and are most effectively used in different environments, for different purposes., In computer networking, the medium affects nearly every, aspect of communication. Most important, it determines, how quickly and to whom a computer can talk and how, expensive the process is., , Cable media : Cables have a central conductor that, consists of a wire or fiber surrounded by a plastic jacket., Three types of cable media are twisted-pair, coaxial and, fiber-optic cable. Two types of twisted-pair cable are, used in networks: unshielded (UTP) and shielded (STP)., Table summarizes the characteristics of these types of, cable media, which are discussed in the following sections., , Factor, , UTP, , STP, , Coaxial, , Fiber-optic, , Cost, , Lowest, , Moderate, , Moderate, , Highest, , Installation, , Easy, , Fairly easy, , Fairly easy, , Difficult, , Bandwidth, capacity, , 1- to 155 Mbps, (typically 10 Mbps), , 1- to 155Mbps, (typically 16 Mbps), , Typically, 10 Mbps, , 2 Gbps, (typically 100 Mbps), , Node capacity, per segment, , 2, , 2, , 30 (10base 2), 100 (10 base 5), , 2, , Attenuation, , High (range of, hundreds of meters), , High (range of, hundreds of, meters), , Lower (range of a few, kilometers), , Lowest (range of, tens of kilometers), , EMI, , Most vulnerable to, EMI and, eavesdropping, , Less vulnerable, than UTP but still, vulnerable to EMI, and eavesdropping, , Less vulnerable than, UTP but still vulnerable, to EMI and, eavesdropping, , Not affected by, EMI or, eavesdropping, , Twisted-pair cable : Twisted-pair cable uses one or more, pairs of two twisted copper wires to transmit signals. It is, commonly used as telecommunications cable., When copper wires that are close together conduct, electric signals, there is a tendency for each wire to, produce interference in the other. One wire interferring, with another in this way is called crosstalk. To decrease, the amount of crosstalk and outside interference, the, wires are twisted. Twisting the wires allows the emitted, signals from one wire to cancel out the emitted signals, from the other and protects them from outside noise., Twisted pairs are two color-coded, insulated copper, wires that are twisted around each other. A twisted-pair, cable consists of one or more twisted pairs in a common, jacket. Fig 1 shows a twisted-pair cable., The two types of twisted-pair cable are unshielded and, shielded., 190, , Unshielded twisted-pair cable : Unshielded twistedpair (UTP) cable consists of a number of twisted pairs, with a simple plastic casing. UTP is commonly used in, telephone systems. Fig 2 shows a UTP cable., The Electrical Industries Association (EIA) divides UTP, into different categories by quality grade. The rating for, each category refers to conductor size, electrical characteristics and twists per foot. The following categories are, defined., , Copyright @ NIMI Not to be Republished
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The other side of the punch-down block is wired to a patch, panel. The patch panel provides connectivity through, patch cables to other user devices and connectivity, devices., UTP’s popularity is partly due to the, first usage of the, same in telephone systems. In many cases a network can, be run over the already existing wires installed for the, phone system, at a great savings in installation cost., , – Categories 1 and 2 were originally meant for voice, communication and can support only low data rates,, less than 4 megabits per second (Mbps). These, cannot be used for high-speed data communications., Older telephone networks used Category 1 cable., , Shielded twisted-pair cable : The only difference between shielded twisted pair (STP) and UTP is that STP, cable has a shielded usually aluminium/polyester between, the outer jacket or casing and the wires. Fig 4 shows STP, cable., , – Category 3 is suitable for most computer networks., Some innovations can allow data rates much higher,, but generally Category 3 offers data rates up to 16, Mbps. This category of cable is the kind currently used, in most telephone installations., – Category 4 offers data rates upto 20 Mbps., – Category 5 offers enhancements over Category 3,, such as support for Fast Ethernet, more insulation, and more twists per foot, but Category 5 requires, compatible equipment and more stringent installation., In a Category 5 installation, all media, connectors and, connecting equipment must support Category 5 or, performance will be affected., Data-grade UTP cable (Categories 3,4 and 5) consists of, either four or eight wires. A UTP cable with four wires is, called a two-pair. Network topologies that use UTP, require atleast two-pair wire. You may want to include an, extra pair for future expansion. Fig 3 shows a four-pair, cable., , Because UTP cable was originally used in telephone, systems, UTP installations are often similar to telephone, installations. For a four-pair cable, you need a modular, RJ-45 telephone connector. For a two-pair cable, you, need a modular RJ-11 telephone connector. These, connectors are attached to both ends of a patch cable., One end of the patch cable is then inserted into a, computer or other device, and the other end is inserted, into a wall jack. The wall jack connects the UTP drop, cable (another length of cable) to a punch-down block., , The shield makes STP less vulnerable to EMI because, the shield is electrically grounded. If a shield is grounded, correctly, it tends to prevent signals from getting into or, out of the cable. It is a more reliable cable for LAN, environments. STP was the first twisted-pair cable to be, used in LANs. Although many LANs now use UTP, STP, is still used., Transmission media specifications from IBM and Apple, Computer use STP cable. IBM’s Token Ring network, uses STP and IBM has its own specifications for different, qualities and configurations of STP. A completely different, type of STP is the standard for Apple’s Apple Talk, networks. Networks that confirm to each vendor’s specifications have their own special requirements, including, connector types and limits on cable length., STP has the following characteristics, Cost : Bulk STP is fairly expensive. STP costs more than, UTP and thin coaxial cable but less than thick coaxial or, fiber-optic cabling., Installation : The requirement for special connectors, can make STP more difficult to install than UTP. An, electrical ground must be created with the connectors. To, simplify installation, use standardised and prewired cables., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 191
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Because STP is rigid and thick (up to 1.5 inches in, diameter), it can be difficult to handle., , The following are some coaxial cables commonly used in, networking:, , Bandwidth capacity : With the outside interference, reduced by the shielding, STP can theoretically run at, 500 Mbps for a 100 meter cable length. Few installations, run at data rates higher than 155 Mbps. Currently, most, STP installations have data rates of 16 Mbps., , 50 ohm, RG-8 and RG-11 used for thick ethernet., , Node capacity : Since only two computers can be, connected together by an STP cable, the number of, computers in an STP network is not limited by the cable., Rather, it is limited by the hub or hubs that connect the, cables together. In a Token Ring network, which is the, most common type of STP network, the useful upper limit, is around 200 nodes in a single ring, but it depends on the, type of data traffic in your network. There is a specified, maximum limit of 270, but you will probably never reach, this limit., , PVC and plenum cable : Polyvinyl chloride (PVC) is, commonly used in coaxial cabling because it is a flexible,, inexpensive plastic well suited for use as insulation and, cable jacketing. PVC is often used in the exposed areas, of an office., , Attenuation : STP does not outperform UTP by much in, terms of attenuation. The most common limit is 100, meters., EMI : The biggest different between STP and UTP is the, reduction of EMI. The shielding blocks a considerable, amount of the interference. However, since it is copper, wire, STP still suffers from EMI and is vulnerable to, eavesdropping., Coaxial cable : Coaxial cable commonly called coax, has two conductors that share the same axis. A solid, copper wire or stranded wire runs down the center of the, cable and this wire is surrounded by plastic foam insulation., The form is surrounded by a second conductor, a wire, mesh tube, metallic foil or both. The wire mesh protects, the wire from EMI. It is often called the shield. A tough, plastic jacket forms the cover of the cable, providing, protection and insulation. Fig 5 shows a coaxial cable., , 50 ohm, RG-58 used for thin ethernet., 75 ohm, RG-59 used for cable TV., 93 ohm, RG-62 used for ARCnet., , A plenum is the space between the false ceiling of an, office and the floor above. The air in the plenum circulates, with the air in the rest of the building, and there are strict, fire codes about what can be placed in a plenum, environment., Because PVC gives off poisonous gases when burned,, you cannot use it in a plenum environment. You must use, plenum grade cable instead. Plenum grade cable is, certified to be fire resistant to produce a minimum, amount of smoke. Plenum cable is also used in vertical, runs (walls) without conduit (a tube to hold the cable)., Plenum cable is more expensive and less flexible than, PVC., Fiber-optic cable : Fiber-optic cable transmits light, signals rather than electrical signals. It is enormously, more efficient than the other network transmission media., As soon as it comes down in price (both in terms of the, cable and installation costs) fibre optic will be the choice, for network cabling., Each fiber has an inner core of glass or plastic that, conducts light. The inner core is surrounded by cladding,, a layer of glass that reflects the light back into the core., Each fiber is surrounded by a plastic sheath. The sheath, can be either tight or loose. Fig 6 shows examples of, these two types of fiber optic cables., , Coaxial cable comes in different sizes. It is classified by, size (RG) and by the cable’s resistance to direct or, alternating electric currents (measured in ohms also, called impedance), 192, , Tight configurations completely surround the fibers with, a plastic sheath and sometimes include wires to strengthen, the cable (although these wires are not required). Loose, configurations leave a space between the sheath and the, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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outer jacket, which is filled with a gel or other material., The sheath provides the strength necessary to protect, against breaking or extreme heat or cold. The gel,, strength wires and outer jacket provide extra protection., A cable may contain a single fiber, but often fibers are, bundled together in the center of the cable. Optical fibers, are smaller and lighter than copper wire. One optical fiber, is approximately the same diameter as a human hair., Optical fibers may be multimode or single mode. Single, mode fibers allow a single light path and are typically, used with laser signaling. Single mode fiber can allow, greater bandwidth and cable runs than multimode but is, more expensive. Multimode fibers use multiple light, paths. The physical characteristics of the multimode, fiber make all parts of the signal (those from the various, paths) arrive at the same time, appearing to the receiver, as though they were one pulse. If you want to save, money, look into multimode, since it can be used with, LEDs (light emitting diodes) which are a more affordable, light source than lasers. Fig 7 shows single mode and, multi mode fibers., , bounded media difficult. There are three main types of, wireless media: radio wave, micro wave and infrared., Radio wave transmission systems : Radio waves, have frequencies between 10 kilohertz (KHz) and 1, gigahertz (GHz). The range of the electromagnetic, spectrum between 10 KHz and 1 GHz is called radio, frequency (RF)., Radio wave include the following types., Short wave, Very high frequency (VHF) television and FM radio, Ultra-high frequency (UHF) radio and television, Radio waves can be broadcast omnidirectionally or, directionally. Various kinds of antennas can be used to, broadcast radio signals., Microwave transmission systems : Microwave communication makes use of the lower gigahertz frequencies, of the electromagnetic spectrum. These frequencies,, which are higher than radio frequencies, produce better, throughout and performance. There are two types of, microwave data communication systems: terrestrial and, satellite., Terrestrial microwave : Terrestrial microwave systems, typically use directional parabolic antennas to send and, receive signals in the lower gigahertz range. The signals, are highly focused and the physical path must be line-ofsight. Relay towers are used to extend signals. Terrestrial, microwave systems are typically used when using cabling, is cost prohibitive., Because terrestrial microwave equipment often uses, licensed frequencies, additional costs and time constraints, may be imposed by licensing commissions or government, agencies (the FCC, in the United States)., , Optical fibers are differentiated by core/cladding size, and mode. The size and purity of the core determine the, amount of light that can be transmitted. The following are, the common types of fiber-optic cable., 8.3 micron core/125 micron cladding, single mode, 62.5 micron core/125 micron cladding, multimode, 50 micron core/125 micron cladding, multimode, 100 micron core/140 micron cladding, multimode, A typical LAN installation starts at a computer or network, device that has a fiber-optic network interface and (NIC)., This NIC has an incoming interface and an outgoing, interface. The interfaces are directly connected to fiberoptic cables with special fibre-optic connectors. The, opposite ends of the cables are attached to a connectivity, device or splice center., Wireless media : Wireless media do not use an electrical, or optical conductor. In most cases, the earth’s atmosphere is the physical path for the data. Wireless media is, therefore useful when distance or obstructions make, , Fig 8 shows a microwave system connecting separate, buildings. Smaller terrestrial microwave systems can be, used within a building, as well. Microwave LANs operate, at low power, using small transmitters that communicate, with omnidirectional hubs. Hubs can then be connected, to form an entire network., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 193
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Satellite : Satellite microwave systems transmit signals, between directional parabolic antennas. Like terrestrial, microwave systems, they use low gigahertz frequencies, and must be in line-of-sight. The main difference with, satellite system is that one antenna is on a satellite in, geosynchronous orbit about 50,000 kilometers (22,300, miles) above the earth. Because of this, satellite microwave systems can reach the most remote places on earth, and communicate with mobile devices., Here’s how it usually works: a LAN sends a signal, through cable media to an antenna (commonly known as, a satellite dish), which beams the signal to the satellite in, orbit above the earth. The orbiting antenna then transmits, the signal to the another location on the earth or, if the, destination is on the opposite side of the earth, to another, satellite, which then transmits to a location on earth., Fig 9 shows a transmission being learned from a satellite, dish on earth to an orbiting satellite and then back to, earth., , Because the signal must be transmitted 50,000 kilometers, to the satellite and 50,000 kilometers back to earth,, satellite microwave transmissions take about as long to, cover a few kilometers as they do to span continents., Because the transmission must travel long distances,, satellite microwave systems experience delays between, the transmission of a signal and its reception. These, delays are called propagation delays. Propagation delays, range from .5 to 5 seconds., Infrared transmission systems : Infrared media use, infrared light to transmit signals. LEDs or ILDs transmit, the signals and photodiodes receive the signals. Infrared, media use the tera-hertz range of the electromagnetic, spectrum. The remote controls we use for television,, VCR and CD players use infrared technology to send and, receive signals., , Infrared media use pure light, normally containing only, electromagnetic waves or photons from a small range of, the electromagnetic spectrum. Infrared light is transmitted, either line-of-sight (point-to-point) or broadcast, omnidirectionally, allowing it to reflect off walls and, ceilings. Point-to-point transmission allows for better, data rates, but devices must remain in their locations., Broadcast, on the other hand, allows for more flexibility, but with lower data rates. (Part of the signal strength is, lost with each reflection.), Point-to-point : Infrared beams can be tightly focused, and directed at a specific target. Laser transmitters can, transmit line-of-sight across several thousand meters., One advantage of infrared is that an FCC license is not, required to use it. Also, using point-to-point infrared, media reduces attenuation and makes eavesdropping, difficult. Typical point-to-point infrared computer, equipment is similar to that used for consumer product, with remote controls. Careful alignment of transmitter, and receiver is required. Fig 10 shows how a network, might use point-to-point infrared transmission., , Broadcast : Broadcast infrared systems spread the, signal to cover a wider area and allow reception of the, signal by several receivers. One of the major advantage, is mobility; the workstations or other devices can be, moved more easily than with point-to-point infrared, media. Fig 11 shows how a broadcast infrared system, might be used., Because broadcast infrared signals are not as focussed, as point-to-point, this type of system cannot offer the, same throughout. Broadcast infrared is typically limited, to less than 1 Mbps, making it too slow for most network, needs., Network adapters, sometimes called Network Interface, Cards (NICs) are peripheral cards that plug into the, motherboard of your computer and into a network cable., It is through the network adapter that your computer, communicates on the network. Many newer IBMcompatible computers have built-in networking adapters, for Ethernet., , Because infrared signals are in the terahertz (higherfrequency) range, they have good throughout. Infrared, signals do have a downside: the signals cannot penetrate, Network adapters perform all the functions required to, walls or other objects and they are diluted by strong light, communicate on a network. They convert data from the, sources., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, 194, , Copyright @ NIMI Not to be Republished
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form stored in the computer to the form transmitted or, received (or transceived) on the cable and provide a, physical connection to the network., , How network adapters work : Network adapters receive, the data to be transmitted from the motherboard of your, computer into a small amount of RAM called a buffer., The data in the buffer is moved into a chip that calculates, a checksum value for the chunk and adds address, information, which includes the address of the destination, card and its own address, which indicates where the data, is from. Ethernet adapter addresses are permanently, assigned when the adapter is made at the factory. This, chunk is now referred to as a frame., For example, in Ethernet, the adapter listens for silence, on the network when no other adapters are transmitting., It then begins transmitting the frame one bit at a time,, starting with the address information, then the chunk of, data and then the checksum., , Fig 12 shows how an adapter plugs into a computer and, attaches to a network cable., , The network adapter must still convert the serial bits of, data to the appropriate media in use on the network. For, instance, if the data is being transmitted over optical, fiber, the bits are used to light up an infrared LED (light, emitting diode) or laser diode, which transmits light, pulses down the fiber to the receiving device’s APD, (avalanche photo diode) or photo-transistor. If the data is, being sent over twisted-pair cable, the adapter must, convert the bits of data from the 5-volt logic used in, computers to the differential logic used for digital twistedpair transmission., The circuitry used to perform this media conversion is, called a transceiver. Ethernet is the same no matter what, type of media you use only the transceiver changes., Transceivers can be external devices attached through, the AUI port on an Ethernet adapter, or they can be, internal on the card. Some cards (usually called combo, cards) have more than one type of transceiver built in so, you can use them with your choice of media. AUI, interfaces on Ethernet adapters are not transceiversthey are where you attach a transceiver for the different, media types., , Adapters in Abstract : Your computer software does not, have to be aware of how the network adapter performs its, function because the network driver software handles all, the specifics for your computer. The applications running, on your computer need only address data and hand it to, the adapter card., This is much the way the post office or a parcel delivery, service works. You don’t care about the details of postal, delivery; you simply address your parcel and hand it to, the delivery driver. The postal service manages the, process of delivering it for you., This abstraction allows your computer to use a microwave, radio transmitter just as earily as a fiber-optic network, adapter or an adapter that works over coaxial cable., , Because a network signal travels through copper and, optical fiber at about 66 percent as fast as the speed of, light, there’s a chance that one of two adapters far away, from each other could still be hearing silence when the, other has in fact started transmitting. In this case, they, could transmit simultaneously and garble their data. This, is referred to as a collision., While adapters transmit, they listen to the wire to make, sure the data on the line matches the data being transmitted. As long as it does, everything is fine. If another, adapter has interrupted, the data being, “heard” by the, transmitting network adapter will not match the data, being transmitted. If this happens, the adapter ceases, transmitting and transmits a solid on state instead, which, indicates to all computers that it has detected a collision, and that they should discard the current frame because, it has been corrupted. The network adapter waits a, random amount of time and then again attempts to, transmit the frame., , Everything in your computer remains the same except for, the actual network adapter and the driver software for that, adapter., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 195
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Configuring network adapters : Because network adapters have not been around since computers were invented,, there is no assigned place for cards to be set to. Most, adapter cards require their own interrupt, port address and, upper memory range. PCI motherboards automatically, assign IRQ and post settings to your PCI card, so you don’t, need to worry about it., Unfortunately, network adapters in computers with ISA, buses can conflict with other devices, since no two devices, , 196, , should share the same interrupt or port. No software that, comes with your computer will tell you every interrupt and, port in use unless your computer is already running, Windows NT, so you must be somewhat familiar with the, hardware in your computer or use a program that can probe, for free resources to find one. Many adapters have test, programs that can tell you whether the adapter is working, correctly with the settings you’ve assigned., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73A, , Computer name and workgroup - Client server, Objectives : At the end of this lesson you shall be able to, • define computer name, • define workgroup, • explain client-server model, centralised computing and client computing with central file storage, • explain web server., Computer Name: In network computers are identified by, its IP Address, but a name can also be given to identify it, easily as remembering IP address is difficult comparing, remembering a alphanumeric name., Client-Server : The term Client-Server can describe, hardware, in which case it is referring to network servers, and client computers, or it can refer to a way of organising, software applications and services on a network. Clientserver computing is a powerful way of constructing, programs on a network. In order to describe its advantage, and how it works, we will first describe two alternatives to, client-server computing:, – Centralised computing, – Client computing with central file storage, Centralized computing : Centralized computing originated with mainframe computers and time-sharing. The, principle behind centralized computing is that a central, computer executes a program, such as a database or a, transaction-processing program (for instance, an airline, reservations system or a bank records program) and, remote terminals merely display data on a screen and, convey keyboard data back to the central computer., , Workgroup: In a network computers can be grouped, together by using workgroup feature. Computers in a, particular workgroup will show together when you open a, workgroup. Though a computer of one workgroup can, access other workgroup computers also., Client computers cooperate to ensure that central files, are not corrupted by attempts by several computers to, access them at the same time. When a client computer, needs to perform an operation, the file is transferred to, the client computer to perform the operation. Two, examples of this type of application are networked, database programs that do not use a SQL. (Structured, Query Language) server and any network-aware, application that does not communicate with a special, program executing on the server, such as network, scheduling programs and groupware., , In modern networks, personal computers can perform, the role of dumb terminals. With Windows software, the, PC can appear to the central computer as many terminals,, each virtual terminal accessing different data or, performing a separate transaction on the mainframe., In centralized computing it is the central computer that, does all the work. The data resides on the central, computer and the program executes on the central, computer. The personal computer or dumb terminal only, display screen data and accepts keystrokes for the, central computer to process. Centralized computing, does not fully use the capabilities of today’s powerful, network clients. Fig 1 illustrates centralized computing., Client computing with Central file storage : At the, opposite end of the spectrum from centralized computing, is client computing with central file storage (see Fig 2). In, this way of organizing an application, the client computer, does all the work. A central file server stores, but that is, all., , Copyright @ NIMI Not to be Republished, , 197
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One example of a front end is Microsoft Access when it, is used with a SQL back end. (You can also use Access, without a SQL back end.) Access displays tables in, windows or in forms you can browse. It allows you to, modify and search the tables in an easy-to-use graphical, environment. All the actual data manipulation, however,, occurs on the SQL server. Access translates all the database operations into SQL for the server to perform. The, results of the operations are transmitted back to Access, to display in an intuitive, graphical form., , While it is fully exploits the capabilities of client computers, and provides a richer and more customizable environment, for the user, this type of program can place heavy, demands on the network if the data files in which program, works with are large. It also takes time to transmit data, from the server to the client, process the data, and, transfer it back to the server so other network programs, can access the data., The Client-Server Model : The client-server model, combines the advantages of both the centralized, computing model and the client model of computing. It, does this by performing the operations that are best, executed by a central computer on the file server and, performing those operations that are best done close to, the user on the client computer (see Fig 3). The clientserver model works best when many people need access, to large amounts of data. Simply stated, a client-server, system is any system in which the client computer makes, a request over a network to a server computer that then, satisfies the request., The Client : When you use a client-server system, what, you see is the client, or front end. It presents the interface, to manipulate or search for data. The request you make, by manipulating windows, menu, check boxes and so on,, is translated into a compact form that the client transmits, over the network for the server to perform., , SQL is not limited to database programs such as Microsoft, Access. User programs such as Microsoft Excel can use, SQL to query the back-end data-base server for values, to use in spreadsheet calculations. Program tools allow, custom programs to store and retrieve data in serverbased databases. Query tools provide direct access to, the SQL data., The Server : The server is where data operations in a, client-server system occur. The central computer can, service many client requests quickly and efficiently,, which is the traditional advantage of centralized, computing. The central computer can also provide, enhanced security by performing only authorized, operations on the data., Back-end database software is optimized to perform, searches and sorts and the back-end computer is often, more powerful than the front-end computer., Web server : A web server is a program using the client/, server model and the World Wide Web’s Hyper Text, Transfer Protocol (HTTP) serves the files that form web, pages to web users., Every computer on the internet that contains a web site, must have a web server program. The most popular web, servers are: The Microsoft’s Internet Information Server, (IIS) which comes with the Microsoft’s Windows NT, Server; Netscape Fast Track and Enterprises Servers, and Apache, a web server for Unix-based operating, systems. Other web servers include Novell’s Web Server, for users of its Netware Operating System and IBM’s, family of Lotus Domino Servers. Primarily for IBM’s OS/, 390 and AS/400 customers., Web servers often come as a part of a larger package of, Internet related programs for serving e-mail, downloading, requests for File Transfer Protocol (FTP) files and building, and publishing web pages. Consideration in choosing a, web server include how well it works with the operating, system and other servers, its ability to handle server side, programming and publishing, search engine and site, building tools that may come with it., , 198, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished
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DHCP, Objectives : At the end of this lesson you shall be able to, • define DHCP, • explain DHCP., DHCP: Dynamic Host Control Protocol allows server, computers to distribute dynamic IP address when the, client establish connection to server. The server, maintains a IP address pool and it offer some IP which, is not already alloted to some other client. When client, disconnects from server its IP then becomes free again, and can be given to other client., , superseded by RFC 2131) that allows a server to, dynamically distribute IP addressing and configuration, information to clients. Normally the DHCP server, provides the client with at least this basic information:, , It is dynamic as same client can get different IP in, different times. It is beneficial as requirement of IP, address is less a all the clients are not always connected, to server and its saves the time to allocate IP to each, client manually., Dynamic Host Configuration Protocol (DHCP) is a, standard protocol defined by RFC 1541 (which is, , •, , IP Address, , •, , Subnet Mask, , •, , Default Gateway, , Other information can be provided as well, such as, Domain Name Service (DNS) server addresses and, Windows Internet Name Service (WINS) server, addresses. The system administrator configures the, DHCP server with the options that are parsed out to the, client., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished, , 199
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73B, , Concept of proxy server, Objectives : At the end of this lesson you shall be able to, • explain the meaning of proxy server, • explain common connection point, • explain packet filtering, domain filtering and control user access by service, • explain logging and web publising., What is a proxy server? To be a “proxy” means to act on, behalf of another. This is exactly what a proxy server does;, it acts on behalf of its proxy clients to interact with other, servers. You could say that a proxy server is a “mediator”, for computer communications., Placing a proxy server on your network gives you several, advantages, including security enhancements, coaching, enhancements and greater control over your network, users. The advantages of using Microsoft Proxy Server, (MPS) is listed below:, – Common connection point, – Caching, – Packet filtering, – Domain filtering, – Control user access by service, – Logging, – Web publishing, Common connection point : MPS was designed to, connect two networks, rather like a gateway. Typically,, MPS connects an internal network and the Internet. This, configuration gives the internal computers a common, connection point to the Internet-through MPS., When used to provide a common connection, MPS lets, clients share a single connection to the Internet. Instead of, giving each user on a Local Area Network (LAN) a separate, modem, phone line and dial-up account to the Internet,, MPS can function as a gateway to the Internet using a, single connection. Instead of using separate standard, phone line connections, users can share a single higherspeed connection through the proxy server. The net effect, is usually an overall cost savings and reduction in administrative overhead. One connection is usually cheaper and, easier to maintain than several separate connections., Caching : Since you can use MPS as a common connection point to the Internet, you can also use it to cache, frequently accessed resources. MPS allocates a portion of, the server’s hard disk space to store frequently accessed, objects., Caching can either be passive or active. Passive caching, just stores objects as they are requested so the cache is, updated only when users request information. Active, caching directs the server to refresh objects in the cache, automatically., 200, , You can selectively control MPS caching so that you can, limit the size of cached objects, change the expiration, limits (control the freshness of objects) and determine, whether MPS always caches or always excludes from, cache certain content., Caching only works with the Web Proxy Service, in MPS. You will learn more about the Web Proxy, Service later in this chapter., Packet Filtering : To protect internal users from the, outside world (in other words to protect the network from, outsiders), MPS provides packet-filtering services. A packet, filter prevents unauthorized access from the outside by, limiting the available connection points coming into the, network. To that end, packet filters stop various types of, protocols from entering the network., MPS supports both static and dynamix packet filters. A, static filter keeps all traffic of a certain description or type, from passing through MPServer. A dynamic packet filter, automatically determines which type of traffic is allowed in, or out. With a static filter the administrator defines the port,, the protocol and may be the IP address. With a dynamic, filter the administrator just defines the service to be allowed, or filtered., Domain Filtering : MPS also lets you limit the access of, your internal clients to the Internet. You can configure, filters for a single computer, a group of computers or a, domain name. Many companies prefer to have this type of, control over their users because they can block access to, Internet sites that they believe reduce employee productivity or contain offensive material. Some popular examples, of domain filtering are blocking access to Internet game, servers or Web sites that contain pornographic material., You can configure domain filters for a specific IP address,, IP address and subnet mask or domain name. IP address, filters prevent users from contacting a single computer., Using the IP address and subnet mask as a filter limits, access to an entire group (a subnet) of computers. Domain, name filters can apply to an entire Web site or to subsections of that site., Control user access by Protocol or Service : You can, also selectively enable and disable ports, services and, protocols through MPS. MPS lets you control access to, Internet services at the user level. You can also enable or, restrict access to protocols on a user or group basis. Many, protocols are predefined in the default MPS configuration., , Copyright @ NIMI Not to be Republished
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If the protocol or service you would like to enable or disable, is not defined in the MPS property sheets, you can create, a new sheet. you can define a protocol by TCP (Transmission Control Protocol) or UDP (User Datagram Protocol), port number or range. This gives you the ability to control, access by port., Logging : Because all traffic between networks passes, through MPS, MPS has the unique opportunity to log and, track communication. You can track the information your, internal clients get from other networks or the Internet and, monitor inbound communication. You can use this information to help you secure your internal network from attack, and unauthorized access. Plus, you can monitor where, your users spend their time on the Internet and what, information they are downloading., Web publishing : MPS can also act as a Web server., MPS can service requests from cache on behalf of a Web, server, pass requests to the Web server on the local, system or pass requests to another Web server on the, internal network. The terms “reverse proxying” and “reverse, hosting” describe the Web Publishing services that MPS, provides., As a reverse proxy, MPS listens to incoming Web requests, for a single Web server on the local network. The incoming, requests are simply forwarded to another Web server. Web, hosting requires more work on the part of MPS. As a, reverse host, MPS can send requests to one of many Web, servers. In this case, MPS responds as if the entire site, were contained locally, even though the actual data may be, coming from several different Web servers., The main difference between reverse proxying and reverse, hosting is that in performing reverse proxying, MPS forwards all requests to the Web server. In performing reverse, hosting, MPS selectively forwards requests to multiple, Web servers on the internal network. In reverse hosting, the, Microsoft Proxy Server routes an external request for a, resource (that specifies an Internet domain name) to one, or more internal Web servers. For instance, requests for, http://www.hudlogic.com/bios might be routed to an internal server named “business” (http://business), while requests for http://www.hudlogic.com/pictures could be sent, to a different Web server named “server1” (http://server1)., Services : Microsoft Proxy Server 2.0 supports Hypertext, Transfer Protocol (HTTP) version 1.1, Windows Sockets, version 1.1, SOCKS version 4.3a and Secure Sockets, Layer (SSL) 3.0. The MPS services that provide this, support are the Web Proxy service, WinSock Proxy, service and the SOCKS Proxy service, respectively., , Web Proxy Service : The Web Proxy service provides, support for HTTP (a.k.a.Web publishing), FTP, Gopher and, secure (SSL) communications. The Web Proxy service, works with any CERN-compliant Web browser, such as, Internet Explorer or Netscape Navigator. Because the Web, Proxy supports only these widely adopted Internet standard communication methods, it isn’t operating system, dependent. Clients running Unix, Macintosh or Windows, operating systems can communicate with the Web Proxy, service as long as they’re configured with a CERN-complaint Web browser., Any operating system using a CERN-compliant, Web browser can communicate through the Web, Proxy server, regardless of its underlying operating system., WinSock Proxy Service : The WinSock Proxy service, supports Microsoft Windows operating systems using, Windows Sockets. This supprt is available for both Transmission Control Protocol/internet Protocol (TCP/IP) and, Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocols. The WinSock Proxy service, applies mainly to Windows clients including Windows 3.x,, windows 95 and Windows NT., Windows Sockets is an interprocess communication, mechanism derived from the Berkeley Sockets interface, (originally designed for Unix systems). The Sockets interface was extended to support Windows-based clients, running Microsoft implementations of TCP/IP. The name, given to this Sockets interface for Windows was WinSock, (for Windows Sockets)., The WinSock Proxy Service doesn’t support 16-bt, IPX/SPX clients such as the Windows 3.x 16-bit, Netware clients., SOCKS Proxy Service : The SOCKS Proxy service, supports SOCKS version 4.3a client applications such as, FTP, Gopher and Telnet. Operating systems like Macintosh and Unix can run SOCKS 4.3a and access the, SOCKS Proxy service when communicating through the, Microsoft Proxy Server. One limitation of the SOCKS proxy, service on MPS is that it does not support UDP-based, protocols., UDP-based protocols aren’t supported through, the SOCKS Proxy service, but the WinSock Proxy, service does support UDP for Windows clients., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73B, , Copyright @ NIMI Not to be Republished, , 201
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.74, , Video conferencing, Objectives: At the end of this lesson you shall be able to, • define video conferencing, • list the advantages of video conferencing, • list the disadvantages of video conferencing., Video Conferencing, , and eye contact in these. Video conferencing allows, users to successfully convey, creating essential social bonds and shared understandings., , Definition: Videoconferencing is the conduct of a conference by a set of telecommunication technologies, which allow two or more remotely located teams to communicate by simultaneous two-way video and audio, transmissions. It has also been called 'visual collaboration' and is a type of groupware., , 5 Increased Productivity, , Video conferencing is a very useful technique to cut down, various costs as well as travel time when meetings and, conferences are concerned.Video conferencing connects, individuals in real time through audio and video communication over broadband networks. It enables visual, meetings and collaboration on digital documents and, shared presentations. New technologies allow participants to connect remotely over a network through multiple devices like laptops, desktops, smartphones and, tablets., , 7, , Advantages, 1 Significant Travel Savings, 2 Not only is video conferencing a direct replacement, for many in-person business trips, but because there, is virtually no cost to add additional key employees, to a virtual meeting, it is a cost effective solution., , 6 Important meetings are shorter and more effective., But it is a well-known fact that many meetings take, longer than the necessary time of the participants., Video conferencing users can save a minimum of, two hours a week with the technology. The interactivity, of group collaboration and document sharing greatly, increases productivity., Conferencing Quality, , 8 The present day state-of-the-art technology delivers, excellent, reliable audio and video quality, making, conferencing very effective and interesting too., Disadvantages, 1 Absence of Physical Presence, 2 Initial installation costs, 3 Not yet popular with a large size of users., , 3 Improved Communication, 4 Audio conferencing and e-mail may be used for communication but there is a lack of visual connection, , 202, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.75, , Network security, Objectives: At the end of this lesson you shall be able to, • define network security, • explain network security concepts., Network security consists of the provisions and policies, adopted by a network administrator to prevent and, monitor unauthorizedaccess, misuse, modification, or, denial of a computer network and network-accessible, resources. Network security involves the authorization, of access to data in a network, which is controlled by the, network administrator., Network security concepts, Network security refers to any activities designed to, protect your network. Specifically, these activities protect, the usability, reliability, integrity, and safety of your, network and data. Effective network security targets a, variety of threats and stops them from entering or, spreading on your network., Network security starts with authenticating, commonly, with a username and a password. Since this requires, just one detail authenticating the user name -i.e. the, password- this is sometimes termed one-factor, authentication. With two-factor authentication, something, the user needs a 'dongle', an ATM card, or a mobile, phone, and with three-factor authentication, something, the user needs a fingerprint or retinal scan., Once authenticated, a firewall decides what services, are allowed to be accessed by the network users. Though, effective to prevent unauthorized access, this component, may fail to check potentially harmful content such as, computer worms or Trojans being transmitted over the, network., Anti-virus software or an intrusion prevention system, (IPS) helps detect and inhibit the action of such malware., Encrypting the communication between two hosts using, a network helps maintain privacy., Surveillance and early-warning toolssometimes referred, to as Honeypots can be employed., Hhoneypot is a trap set to detect, deflect, or, in some, manner, counteract attempts at unauthorized use of, information systems. Generally, a honeypot consists of, a computer, data, or a network site that appears to be, part of a network, but is actually isolated and monitored,, and which seems to contain information or a resource of, value to attackers. This is similar to the police baiting a, criminal and then conducting undercover surveillance., , The Foundations of Security, Security relies on the following elements:, •, , Authentication, , Authentication addresses the question: who are you? It is, the process of uniquely identifying the clients of your, applications and services. These might be end users,, other services, processes, or computers. In security, parlance, authenticated clients are referred to as, principals., •, , Authorization, , Authorization addresses the question: what can you do?, It is the process that governs the resources and, operations that the authenticated client is permitted to, access. Resources include files, databases, tables, rows,, and so on, together with system-level resources such as, registry keys and configuration data. Operations include, performing transactions such as purchasing a product,, transferring money from one account to another, or, increasing a customer's credit rating., •, , Auditing, , Effective auditing and logging is the key to nonrepudiation. Non-repudiation guarantees that a user, cannot deny performing an operation or initiating a, transaction. For example, in an e-commerce system,, non-repudiation mechanisms are required to make sure, that a consumer cannot deny ordering 100 copies of a, particular book., •, , Confidentiality, , Confidentiality, also referred to as privacy, is the process, of making sure that data remains private and confidential,, and that it cannot be viewed by unauthorized users or, eavesdroppers who monitor the flow of traffic across a, network. Encryption is frequently used to enforce, confidentiality. Access control lists (ACLs) are another, means of enforcing confidentiality., •, , Integrity, , Integrity is the guarantee that data is protected from, accidental or deliberate (malicious) modification. Like, privacy, integrity is a key concern, particularly for data, passed across networks. Integrity for data in transit is, typically provided by using hashing techniques and, message authentication codes., , Copyright @ NIMI Not to be Republished, , 203
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•, , Availability, , How Do You Build a Secure Web Application?, , From a security perspective, availability means that, systems remain available for legitimate users. The goal, for many attackers with denial of service attacks is to, crash an application or to make sure that it is sufficiently, overwhelmed so that other users cannot access the, application.Threats, Vulnerabilities, and Attacks Defined, A threat is any potential occurrence, malicious or, otherwise, that could harm an asset. In other words, a, threat is any bad thing that can happen to your assets., A vulnerability is a weakness that makes a threat, possible. This may be because of poor design,, configuration mistakes, or inappropriate and insecure, coding techniques. Weak input validation is an example, of an application layer vulnerability, which can result in, input attacks., , It is not possible to design and build a secure Web, application until you know your threats. An increasingly, important knowledge needed is about threat modeling., The purpose of threat modeling is to analyze your, application's architecture and design and identify, potentially vulnerable areas that may allow a user,, perhaps mistakenly, or an attacker with malicious intent,, to compromise your system's security., After you know your threats, design with security in mind, by applying proven security principles. You must follow, secure coding techniques to develop secure, robust, and, hack-resilient solutions. The design and development of, application layer software must be supported by a secure, network, host, and application configuration on the, servers where the application software is to be deployed., , An attack is an action that exploits a vulnerability or, enacts a threat. Examples of attacks include sending, malicious input to an application or flooding a network in, an attempt to deny service., , 204, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.75, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.76 & 1.11.77, , E-mail, Objectives : At the end of this lesson you shall be able to, • state the hotmail services offered, • explain MSN outlook express and its tools, • explain popular search engines, • state the FAQs about hotmail., Hotmail: MSN Hotmail is the world’s largest provider of, free Web-based e-mail. Hotmail is based on the premise, that e-mail access should be easy and possible from any, computer connected to the World Wide Web., By adhering to the universal HyperText Transfer Protocol, (HTTP) standard, Hotmail eliminates the disparities that, exist between different e-mail programs. Sending and, receiving e-mail from Hotmail is as easy as going to the, Hotmail web site at http://www.hotmail.com, or by clicking, on the Hotmail link at http://www.msn.com, signing in,, and sending an e-mail message., Hotmail is the web-based e-mail provider, which means, you can send and receive messages from any computer, connected to the Internet. You can use Hotmail from, home, work, school, an Internet cafe, a friend’s house or, any other computer in the world with an Internet connection. Your messages are stored in a central location, so, your Inbox will always be up to date. This is great for, people who use more than one computer, travel frequently, or don’t even own a computer., Advantages of Hotmail, Get a permanent e-mail address: When you create a, Hotmail account, you choose a permanent e-mail address that will never change as long as you continue to, use Hotmail. This is great for people who: Want to switch, Internet Service Providers. Your Hotmail address will be, the same no matter how you access the Internet, so you, don’t have to worry about retrieving messages from your, old address or notifying friends, family and associates of, a new e-mail address. You are free to select any Internet, Service Provider that suits your needs., When you leave town for travel, you may no longer have, access to your ISP’s e-mail account. But with Hotmail,, your friends will always know where to reach you., Your e-mail is private and secure: When you sign up, for Hotmail, you choose your personal ID and password., The only way you can access your account is by using the, password you selected. This means that only you will, have access to your Hotmail account, even if you use a, computer at a public terminal or a friend’s house. Because, the messages in your Hotmail account are stored securely at a central location, you don’t have to worry about, losing important information if something happens to, your computer. Hotmail is strongly committed to keeping, your personal information confidential., , Hotmail is fast and easy to use: Hotmail is recognized, world wide as the best Web-based e-mail service. It is, also stated that ‘while others provide similar services,, none can match Hotmail’s general ease of use’. If everything is fine, it takes less than a minute to get started on, Hotmail and its pages are so worked out to load quickly, knowing that the users time is valuable., Get an additional e-mail account for FREE:Hotmail, offers everyone the opportunity to get a free e-mail, account. Hotmail can offer e-mail accounts for free, because it places banner advertising on some of its, pages. Some Internet Service Providers charge a monthly, fee for additional e-mail accounts. Hotmail lets an, unlimited number of people use a single Internet Service, Provider account and have a free, personal e-mail, account., Keep your personal e-mail separate from your work, e-mail: People who use e-mail for work will find it, convenient to keep their personal messages separate, from their work messages. You can use Hotmail for your, personal correspondence and your company’s e-mail, system only for business messages. Additionally, you, don’t have to store personal e-mail on your company’s, servers. All messages in your Hotmail account are, securely stored in a central location that you access via, the Internet with the password you select., Outlook Express, Microsoft Outlook Express puts the world of online, communication on your desktop. Whether you want to, exchange e-mail with colleagues and friends or join, newsgroups to trade ideas and information. Some of the, tools offered by outlook express are;, Manage multiple mail and news accounts: If you have, several mail or news accounts, you can use them all from, one window. You can also create multiple users, or, identities, for the same computer. Each identity gets its, own mail folders and Address Book. The ability to create, multiple accounts and identities makes it easy for you to, keep work separate from personal mail and also between, individual users., Browse through messages quickly & easily: Using, the message list and preview pane, you can view a list of, messages and read individual messages at the same, time. The Folders list contains mail folders, news servers,, and newsgroups, and you can easily switch between, them. You can also create new folders to organize and, sort messages, and then set up message rules so that, , Copyright @ NIMI Not to be Republished, , 205
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incoming mail that meets your criteria automatically, goes to a specific folder. You can also create your own, views to customize the way you look at your mail., Keep your mail on a server so you can view it from, more than one computer: If your ISP uses an IMAP, mail server for incoming mail, you can read, store, and, organize your messages in folders on the server without, downloading the messages to your computer. That way,, you can view messages from any computer that can, connect to that server., Use the Address Book to store and retrieve e-mail, addresses: You can save names and addresses in your, Address Book automatically by simply replying to a, message or by importing them from other programs, by, typing them in, by adding them from e-mail messages, you receive, or by searching popular Internet directory, services (white pages). The Address Book supports, Lightweight Directory Access Protocol (LDAP) for, accessing Internet directory services., Add a personal signature or stationery to your messages: You can insert essential information into outgoing messages as part of your personal signature, and you, can create multiple signatures to use for different, purposes. For more detailed information, you can include, a business card. To make your messages look more, attractive, you can add stationery patterns and backgrounds, and you can change the color and style of the, text., Send and receive secure messages: You can digitally, sign and encrypt messages by using digital IDs. Digitally, signing your message assures recipients that the message is really from you. Encryption ensures that only, intended recipients can read a message., Find newsgroups that interest you: Looking for a, newsgroup that matches your interests? You can search, for newsgroups that contain keywords or browse through, all of the newsgroups available from your Usenet provider. When you find a newsgroup you want to view, regularly, add it to your Subscribed list so you can find it, again easily., View newsgroup conversations efficiently: You can, view a newsgroup message and all of the responses, without reading an entire message list. When you view, the list of messages, you can expand and collapse, conversations to make it easier to find what interests you., You can also use views to display only the messages you, want to read., Download newsgroup messages for offline reading:, To use your online time efficiently, you can download, messages or entire newsgroups, so you don’t have to be, connected to your ISP to read messages. You can also, download message headers only for offline viewing and, then mark the headers of the messages you want to read;, then the next time you are connected, Outlook Express, downloads the message text. You can also compose, messages offline and send them the next time you, reconnect., 206, , Some important (Top 8 ) recommendations for staying, safe and secure when you’re online are listed below;, – Change your password often. The quick act of changing your password can ensure your e-mail remains, private. In addition,passwords that use both letters, and numbers are harder to break., – Don’t share your password. Most e-mail administrators will not ask for your password. Do not be duped, by malicious e-mails asking you for your password., This is a well-known, although not-too-common trick, designed to fool you into sharing your password. As, a rule, never share it with anyone., – Never open attachments from unknown sources., They may contain what are known as “letterbombs” or, “viruses,” which can damage your PC., – Always remember to sign out when you are done. It’s, quick, easy and may save your account from unwanted trespassers. If you are using a public terminal,, at an internet cafe for example, it is advised that you, close the browser you were using when you are ready, to end your Internet session., – Don’t reply to unsolicited messages (“spam”) mail, or, other harassing or offensive mail. By responding, you, only confirm that you are a person with an active email address who can be plagued with constant, unwanted e-mail solicitations. Instead, forward the, unsolicited message to the customer service, department of the source’s e-mail (usually of a form, similar to, abuse@[implicateddomain].com). To, help control spam, Hotmail provides members with, “filters” for incoming mail. These can easily be set up, to send certain messages (such as those that include, certain words) directly to your online trash can., – Make sure that you are using the most up-to-date, Internet software (e.g. browsers such as Microsoft, Internet Explorer or Netscape Navigator). More recent, versions often offer enhanced security protection., – Always use a secure network. Most corporate networks and Internet service providers are protected by, administrators who watch for potential security problems and act to protect users from “hackers” (malicious users) who may try to steal personal information, that is transferred through the network. Although the, risk is small, use caution when on any unfamiliar, network., – Use stations maintained by sources you trust, or ask, if the Internet terminal you are using is protected, against security break-ins., A SMALL LIST OF Search Engines, Yahoo.com (http://www.Yahoo.com), Search.com (http://search.com), EasySearcher (http://www.easysearcher.com), AltaVista (http://www.altavista.com), Excite (http://www.excite.com), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
Page 475 : Google (http://www.google.com), Hotbot (http://www.hotbot.com), Infoseek (http://www.infoseek.com), Lycos (http://www.lycos.com), WebCrawler (http://www.webcrawler.com), www.all4one.com (This useful tool queries four search, engines at once), , Also, MSN has introduced Preview 2 of MSN Explorer as, an integrated client for MSN services, such as MSN, Hotmail. This client allows you to also store Hotmail, locally on your machine. This too reduces the amount of, storage that you need on hotmail., 2 Can I get Hotmail in different languages?, MSN Hotmail can now be viewed in a variety of languages., , www.askjeeves.com (Insted of entering words to search, for, just type in your question), , You can make the language of a Hotmail session match, the language of the Sign In page used to begin that, session. You have your choice of the following languages: English, French, German, Italian, Japanese,, Portuguese (Brazilian), and Spanish, and more to come., , www.rediff.com (Search for anything), , 3 Can I use Hotmail as a business address?, , www.bigfoot.com (Looking for someone’s email address ? Try here), www.hotbot.com (Useful search engine which helps to, find pictures, video or music), , No. You may not use your Hotmail address as your, primary business address. If, however, you work for a, company with which you have an e-mail address and you, want to use your Hotmail account to send and receive email while away from your computer at work, you are, encouraged to do so., , www.indiainfo.com (Info lets you search the web easily), , Example of Prohibited Use:, , www.yahoo.com (Search engine which is also the most, popular), , You are an individual who runs a business. You and your, employees want to use Hotmail accounts rather than, registering and administering your account through a, paid ISP., , www.av.com (Very powerful search engine which gives, plenty of results), , www.sawaal.com (All your questions answered), , mp3.lycos.com (The place to start if you’re after music, files in the mp3 format), www.metacrawler.com (Metacrawler puts your search, through a host different engines), www.mirago.co.uk (A search engine eith an excellent, selection of shopping links), www.webferret.com (One of the easiest way to search, the web), www.indiatimes.com (The portal’s search engine), www.webcrawler.com (Let the webcrawler spider to do, the searching for you), www.indonet.net (Excellent Indian search engine with, loads of useful search catagories), www.satyamonline.com (On ISP’s site and has good, search options), COMPILED LIST OF INTERESTING FAQ’s about, HOTMAIL, 1 How much e-mail storage space do I get with Hotmail?, Hotmail offers 2MB of storage space. If you do not keep, your account below this limit, Hotmail may remove some, messages, which cannot be recovered., If you need additional storage space, there are a few, options. You can use the latest version of Microsoft, Internet Explorer v5 or above, which includes Outlook, Express, which offers you the ability to store e-mails, locally. You can send a blank e-mail message to,
[email protected] for more information on how to, use the beta (pre-release) process to store Hotmail, messages on your local PC, using Outlook Express., , Example of Allowed Use:, You are a businessperson who travels. You have an, account with your company (yourname@your, company.com). You use your Hotmail account to read, and send solicited messages while you are traveling., Hotmail prohibits account sharing. Since Hotmail is, accessible from everywhere in the world, each individual, is able to sign up for his or her own personal account. You, are encouraged to sign up for an account of your own, to, which only you have access. Sharing an account compromises the privacy and security of your e-mail. Each, Hotmail user must have his or her individual e-mail, account., 4 Is my e-mail really private and secure? (SSL)?, Secure connections (often called SSL, or Secure Sockets Layer) is the industry standard in Web security. It is, used primarily for transmitting sensitive information over, the Internet. When you have a secure connection between, your, browser and a Web site, no one else can easily, access the data that you send across the connection., Hotmail uses SSL to encrypt your sign-in name, and, password, when you log in to give you a high level of, security., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished, , 207
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It is Hotmail’s policy to respect the privacy of its users., Therefore, Hotmail will not monitor, edit, or disclose the, contents of a user’s private communications unless, required to do so by law or in the good faith belief that, such action is necessary to:, – conform to the edicts of the law or comply with, legal process served on Hotmail;, – protect and defend the rights or property of, Hotmail; or, – act under exigent circumstances to protect the, personal safety of its users or the public., 5 Can Hotmail protect its users from e-mail viruses?, MSN Hotmail is pleased to offer users McAfee VirusScan, for free. Whenever you receive attachments in your, Hotmail account, it will automatically scan them with, McAfee’s popular VirusScan before downloading., MSN Hotmail recently added the ability to have all, attachments you want to send scanned before they can, be attached to your outgoing e-mail. So before you, upload file to send to another user, it will also be scanned, for viruses before you send it, reducing the spread of, viruses to Hotmail users and the other recipients of your, e-mail., Remember, to ensure safety, Hotmail recommends that, you never open attachments from unknown sources., , You can also accent your messages by using Rich Text, Formatting. The Rich Text Formatting option, also allows, you to add emoticons to your e-mail. This new feature, allows you to add selected symbols or emoticons to your, message. These icons help you convey emotion or add, flair within a message., 7 What does it mean when my account is marked, “inactive”?, Currently, if you do not sign in to your Hotmail account for, 60 days, or if you do not sign-in within the first 10 days,, your account will be marked “inactive.” Stored e-mail and, addresses will be deleted, and inbound mail will be, refused. Your Passport will still function, and your Hotmail, e-mail name will be reserved. To re-activate your account,, simply go to http://www.hotmail.com and enter your, Sign-In name and password. You will then be able to, once again send and receive e-mail using hotmail. If your, account stays “inactive” for over a period of 90 days, it, may be permanently deleted., 8 Can I send and receive attachments on Hotmail?, Yes, you can send and receive as many files as you want, to a message - up to 1MB (1024K) of attachments., Attachments sent to your Hotmail account can be, downloaded to your personal computer by clicking them., GIF and JPEG images and HTML files are automatically, displayed in the browser window., , 6 How do I send images and use e-mail stationery to, make e-mail I send more colorful and fun?, (Emoticons/Stationery/RTF), MSN Hotmail offers users stationery to send fun, colorful, messages to family and friends! Always capture the right, mood for your messages by selecting one of the many, different stationery templates. Use the Stationery Chooser, button on the Compose page to view the available, stationery choices., , 208, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.78, , Chatting, video chatting and using social network sites, Objectives : At the end of this lesson you shall be able to, • explain chating process, • explain video chating process, • explain social network services., Chatting Process, A web chat is a system that allows users to communicate, in real time using easily accessible web interfaces. It is, a type of internet online chat distinguished by its simplicity, and accessibility to users who do not wish to take the, time to install and learn to use specialized chat software., This trait allows users instantaneous access and only a, web browser is required to chat. Users will always get, the latest version of a chat service because no software, installation or updates are required., Video Chat, In video chat video of both caller and receiver can be, seen on screen of both user along with audio. So it gives, an impression of face to face interaction though the caller, and receiver can be thousands of mile apart., Social Networking services, A social networking service is a platform to build social, networks or social relations among people who, share, interests, activities, backgrounds or real-life connections., A social network service consists of a representation of, each user (often a profile), his social links, and a variety, of additional services. Social networking is web-based, services that allow individuals to create a public profile,, to create a list of users with whom to share connection,, and view and cross the connections within the system., Most social network services are web-based and provide, means for users to interact over the Internet, such as email and instant messaging.Social network sites are, varied and they incorporate new information and, communication tools such as, mobile connectivity, photo/, video/sharing and blogging. Online community services, , are sometimes considered as a social network service,, though in a broader sense, social network service usually, means an individual-centered service whereas online, community services are group-centered. Social, networking sites allow users to share ideas, pictures,, posts, activities, events, interests with people in their, network., The main types of social networking services are those, that contain category places (such as former school year, or classmates), means to connect with friends (usually, with self-description pages), and a recommendation, system linked to trust. Popular methods now combine, many of these, with American-based services such as, Facebook, Google+,YouTube, LinkedIn, Instagram,, Pinterest, Tumblr and Twitter widely used worldwide;, Nexopia in Canada; Badoo, Bebo, Vkontakte (Russia),, Delphi (also called Delphi Forums), Draugiem.lv (mostly, in Latvia), Hi5 (Europe), Hyves (mostly in The, Netherlands), iWiW (mostly in Hungary), Nasza-Klasa,, Soup (mostly in Poland), Glocals in Switzerland,Skyrock,, The Sphere, StudiVZ (mostly in Germany), Tagged,, Tuenti (mostly in Spain), and XING in parts of Europe;, Hi5 and Orkut in South America and Central America;, Mxit in Africa; and Cyworld, Mixi, Orkut, renren, weibo, and Wretch in Asia and the Pacific Islands., There have been attempts to standardize these services, to avoid the need to duplicate entries of friends and, interests (see the FOAF standard and the Open Source, Initiative). According to experts, the largest social, networking users are Asian-Pacific regions with 615,9, million people. A 2013 survey found that 73% U.S adults, use social networking sites., , Copyright @ NIMI Not to be Republished, , 209
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.79, , Explaining threats to computers connected to Internet & process of protecting computers from it., Objectives : At the end of this lesson you shall be able to, • explain threats to computers connected to Internet, • process of Protecting computers from Internet., A web threat is any threat that uses the World Wide Web, to facilitate cybercrime. Web threats use multiple types, of malware and fraud, all of which utilize HTTP or HTTPS, protocols, but may also employ other protocols and components, such as links in email or IM, or malware attachments or on servers that access the Web. They benefit, cybercriminals by stealing information for subsequent, sale and help absorb infected PCs into botnets., Web threats pose a broad range of risks, including financial damages, identity theft, loss of confidential information/data, theft of network resources, damaged, brand/personal reputation, and erosion of consumer confidence in e-commerce and online banking., It is a type of threat related to information technology, (IT). The IT risk, i.e. risk affecting has gained and increasing impact on society due to the spread of IT processes., Web threats can be divided into two primary categories,, based on delivery method - push and pull. Push-based, threats use spam, phishing, or other fraudulent means, to lure a user to a malicious (often spoofed) website which, then collects information and/or injects malware. Push, attacks use phishing, DNS poisoning (or pharming), and, other means to appear to originate from a trusted source., Precisely-targeted push-based web threats are often referred to as spear phishing to reflect the focus of their, data gathering attack. Spear phishing typically targets, specific individuals and groups for financial gain. In other, push-based web threats, malware authors use social engineering such as enticing subject lines that reference, holidays, popular personalities, sports, pornography,, world events and other hot topics to persuade recipients, to open the email and follow links to malicious websites, or open attachments with malware that accesses the, Web., Pull-based web threats are often referred to as "driveby" threats by experts (and more commonly as "driveby downloads" by journalists and the general public),, since they can affect any website visitor. Cybercriminals, infect legitimate websites, which unknowingly transmit, malware to visitors or alter search results to take users, to malicious websites. Upon loading the page, the user's, browser passively runs a malware downloader in a hidden HTML frame (IFRAME) without any user interaction., , 210, , Internet security, Internet security is a tree branch of computer security, specifically related to the Internet, often involving browser, security but also network security on a more general level, as it applies to other applications or operating systems, on a whole. Its objective is to establish rules and measures to use against attacks over the Internet. The, Internet represents an insecure channel for exchanging, information leading to a high risk of intrusion or fraud,, such as phishing. Different methods have been used to, protect the transfer of data, including encryption., Types of security, Network layer security, TCP/IP which stands for Transmission Control Protocol, (TCP) and Internet Protocol (IP) aka Internet protocol, suite can be made secure with the help of cryptographic, methods and protocols. These protocols include Secure, Sockets Layer (SSL), succeeded by Transport Layer, Security (TLS) for web traffic, Pretty Good Privacy (PGP), for email, and IPsec for the network layer security., Internet Protocol Security (IPsec), This protocol is designed to protect communication in a, secure manner using TCP/IP aka Internet protocol suite., It is a set of security extensions developed by the Internet, Task force IETF, and it provides security and authentication at the IP layer by transforming data using encryption. Two main types of transformation that form the basis, of IPsec: the Authentication Header (AH) and ESP. These, two protocols provide data integrity, data origin authentication, and anti-replay service. These protocols can be, used alone or in combination to provide the desired set, of security services for the Internet Protocol (IP) layer., The basic components of the IPsec security architecture are described in terms of the following functionalities:, •, , Security protocols for AH and ESP, , •, , Security association for policy management and traffic processing, , •, , Manual and automatic key management for the, internet key exchange (IKE), , •, , Algorithms for authentication and encryption, , Copyright @ NIMI Not to be Republished
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The set of security services provided at the IP layer, includes access control, data origin integrity, protection, against replays, and confidentiality. The algorithm allows, these sets to work independently without affecting other, parts of the implementation. The IPsec implementation, is operated in a host or security gateway environment, giving protection to IP traffic., Security token, Some online sites offer customers the ability to use a, six-digit code which randomly changes every 30-60, seconds on a security token. The keys on the security, token have built in mathematical computations and, manipulate numbers based on the current time built into, the device. This means that every thirty seconds there, is only a certain array of numbers possible which would, be correct to validate access to the online account. The, website that the user is logging into would be made aware, of that devices' serial number and would know the, computation and correct time built into the device to verify, that the number given is indeed one of the handful of, six-digit numbers that works in that given 30-60 second, cycle. After 30-60 seconds the device will present a new, random six-digit number which can log into the website., Electronic mail security (E-mail), Background, Email messages are composed, delivered, and stored, in a multiple step process, which starts with the message's, composition. When the user finishes composing the, message and sends it, the message is transformed into, a standard format: an RFC 2822 formatted message., Afterwards, the message can be transmitted. Using a, network connection, the mail client, referred to as a mail, user agent (MUA), connects to a mail transfer agent, (MTA) operating on the mail server. The mail client then, provides the sender's identity to the server. Next, using, the mail server commands, the client sends the recipient, list to the mail server. The client then supplies the, message. Once the mail server receives and processes, the message, several events occur: recipient server, identification, connection establishment, and message, transmission. Using Domain Name System (DNS), services, the sender's mail server determines the mail, server(s) for the recipient(s). Then, the server opens up, a connection(s) to the recipient mail server(s) and sends, the message employing a process similar to that used, by the originating client, delivering the message to the, recipient(s)., Pretty Good Privacy (PGP), Pretty Good Privacy provides confidentiality by, encrypting messages to be transmitted or data files to, be stored using an encryption algorithm such Triple DES, or CAST-128. Email messages can be protected by using, cryptography in various ways, such as the following:, •, , Signing an email message to ensure its integrity and, confirm the identity of its sender., , •, , Encrypting the body of an email message to ensure, its confidentiality., , •, , Encrypting the communications between mail servers, to protect the confidentiality of both message body, and message header., , The first two methods, message signing and message, body encryption, are often used together; however,, encrypting the transmissions between mail servers is, typically used only when two organizations want to protect, emails regularly sent between each other. For example,, the organizations could establish a virtual private network, (VPN) to encrypt the communications between their mail, servers over the Internet. Unlike methods that can only, encrypt a message body, a VPN can encrypt entire, messages, including email header information such as, senders, recipients, and subjects. In some cases,, organizations may need to protect header information., However, a VPN solution alone cannot provide a, message signing mechanism, nor can it provide, protection for email messages along the entire route from, sender to recipient., Multipurpose Internet Mail Extensions (MIME), MIME transforms non-ASCII data at the sender's site to, Network Virtual Terminal (NVT) ASCII data and delivers, it to client's Simple Mail Transfer Protocol (SMTP) to be, sent through the Internet. The server SMTP at the, receiver's side receives the NVT ASCII data and delivers, it to MIME to be transformed back to the original nonASCII data., Message Authentication Code, A Message authentication code (MAC) is a cryptography, method that uses a secret key to encrypt a message., This method outputs a MAC value that can be decrypted, by the receiver, using the same secret key used by the, sender. The Message Authentication Code protects both, a message's data integrity as well as its authenticity., Firewalls, A firewall (computing) controls access between networks., It generally consists of gateways and filters which vary, from one firewall to another. Firewalls also screen, network traffic and are able to block traffic that is, dangerous. Firewalls act as the intermediate server, between SMTP and Hypertext Transfer Protocol (HTTP), connections., Role of firewalls in web security, Firewalls impose restrictions on incoming and outgoing, Network packets to and from private networks. Incoming, or outgoing traffic must pass through the firewall; only, authorized traffic is allowed to pass through it. Firewalls, create checkpoints between an internal private network, and the public Internet, also known as choke, points(borrowed from the identical military term of a, combat limiting geographical feature). Firewalls can, create choke points based on IP source and TCP port, number. They can also serve as the platform for IPsec., Using tunnel mode capability, firewall can be used to, implement VPNs. Firewalls can also limit network, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.04, , Copyright @ NIMI Not to be Republished, , 211
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exposure by hiding the internal network system and, information from the public Internet. Also, WE HAVE A, LOT OF BIG WAYE to deal with it., Types of firewalls, Packet filter, , Ransomware and Scareware, Botnet, A botnet is a network of zombie computers that have, been taken over by a robot or bot that performs largescale malicious acts for the creator of the botnet., , A packet filter is a first generation firewall that processes, network traffic on a packet-by-packet basis. Its main job, is to filter traffic from a remote IP host, so a router is, needed to connect the internal network to the Internet., The router is known as a screening router, which screens, packets leaving and entering the network., , Spyware, , Stateful packet inspection, , A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to, make a computer resource unavailable to its intended, users. Although the means to carry out, motives for, and, targets of a DoS attack may vary, it generally consists of, the concerted efforts to prevent an Internet site or service from functioning efficiently or at all, temporarily or, indefinitely., , In a stateful firewall the circuit-level gateway is a proxy, server that operates at the network level of an Open, Systems Interconnection (OSI) model and statically defines what traffic will be allowed. Circuit proxies will forward Network packets (formatted unit of data ) containing a given port number, if the port is permitted by the, algorithm. The main advantage of a proxy server is its, ability to provide Network Address Translation (NAT),, which can hide the user's IP address from the Internet,, effectively protecting all internal information from the, Internet., Application-level gateway, An application-level firewall is a third generation firewall, where a proxy server operates at the very top of the OSI, model, the IP suite application level. A network packet is, forwarded only if a connection is established using a, known protocol. Application-level gateways are notable, for analyzing entire messages rather than individual, packets of data when the data are being sent or received., Malicious software, Malware, A computer user can be tricked or forced into downloading software onto a computer that is of malicious intent., Such programs are known as malware and come in many, forms, such as viruses, Trojan horses, spyware, and, worms. Malicious software is sometimes used to form, botnets., Viruses, Computer Viruses are programs that can replicate their, structures or effects by infecting other files or structures, on a computer. The common use of a virus is to take, over a computer to steal data., Worms, Computer worms are programs that can replicate themselves throughout a computer network, performing malicious tasks throughout., Trojan horse, A Trojan horse commonly known as a Trojan is a general term for malicious software that pretends to be harmless, so that a user willingly allows it to be downloaded, onto the computer., 212, , The term spyware refers to programs that surreptitiously, monitor activity on a computer system and report that, information to others without the user's consent., Denial-of-service attack, , Browser choice, Web browser statistics tend to affect the amount a Web, browser is exploited. For example, Internet Explorer 6,, which used to own a majority of the Web browser market share, is considered extremely insecure because vulnerabilities were exploited due to its former popularity., Since browser choice is more evenly distributed (Internet, Explorer at 28.5%,Firefox at 18.4%, Google Chrome at, 40.8%, and so on) and vulnerabilities are exploited in, many different browsers., Application vulnerabilities, Applications used to access Internet resources may contain security vulnerabilities such as memory safety bugs, or flawed authentication checks. The most severe of, these bugs can give network attackers full control over, the computer. Most security applications and suites are, incapable of adequate defense against these kinds of, attacks., Internet security products, Antivirus, Antivirus programs and Internet security programs can, protect a programmable device from malware by detecting and eliminating viruses; Before 2000 a user would, pay for antivirus software, 10 years later however, computer users can choose from a host of free security applications on the Internet., Security Suites, So called "security suites" were first offered for sale in, 2003 (McAffee) and contain a suite of firewalls, anti-virus, anti-spyware and more.They may now offer theft, protection, portable storage device safety check, private, internet browsing, cloud anti-spam, a file shredder or, make security-related decisions (answering popup windows) and several were free of charge as of at least, 2012., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.79, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.80 & 1.11.81, , Outlook Express & Google+, Objectives : At the end of this lesson you shall be able to, • explain outlook express, • explain Google+, Microsoft Outlook, , Creation, , Microsoft Outlook is a personal information manager from, Microsoft, available as a part of the Microsoft, Officesuite.Although often used mainly as an email, application, it also includes a calendar, task manager,, contact manager,note taking, journal, and web browsing.It, can be used as a stand-alone application, or can work, with Microsoft Exchange Server and Microsoft, SharePoint Server for multiple users in an organization,, such as shared mailboxes and calendars, Exchange, public folders, SharePoint lists, and meeting schedules., There are third-party add-on applications that integrate, Outlook with devices such as BlackBerry mobile phones, and with other software such as Office and Skypeinternet, communication. Developers can also create their own, custom software that works with Outlook and Office, components using Microsoft Visual Studio. In addition,, Windows Mobile devices can synchronize almost all, Outlook data to Outlook Mobile., , Google launched the Google+ service as an invitationonly "field test" on June 28, 2011, but soon suspended, early invites due to an "insane demand" for new accounts., On August 6, each Google+ member had 150 invitations to give outuntil September 20, 2011, when Google+, opened to everyone 18 years of age or older without the, need for an invitation. It was opened for a younger age, group (13 years or older in US and most countries, 14 or, older in South Korea and Spain, 16 or older in the Netherlands) on January 26, 2012. Google+ is available as a, website and on mobile devices., , Google+, Google+ (pronounced and sometimes written as Google, Plus) is a social networking and identity service that is, owned and operated by Google Inc. Google has described Google+ as a "social layer" that enhances many, of its online properties, and that it is not simply a social, networking website, but also an authorship tool that associates web-content directly with its owner/author. It is, the second-largest social networking site in the world, after Facebook. 540 million monthly active users are, part of the Identity service site, by interacting socially with, Google+'s enhanced properties, like Gmail, +1 button, and, YouTube comments. In October 2013, Google counted, 540 million active users who used at least one Google+, service, of which 300 million users are active in "the, stream"., , Before the launch, Google referred to Google+ as Google, Circles, a name alluding to its emphasis on organising, friendship information. Google+ is considered the, company's fourth foray into social networking, following, Google Buzz (launched 2010, retired in 2011), Google, Friend Connect (launched 2008, retired by March 1,, 2012) and Orkut (launched in 2004, as of 2013 operated, entirely by subsidiary Google Brazil). Sources such as, The New York Times have declared it Google's biggest, attempt to rival the social network Facebook, which has, over 1 billion users., , Copyright @ NIMI Not to be Republished, , 213
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IT & ITES, Related Theory for Exercise 1.12.82 to 1.12.92, COPA - Designing Static WebPages, Web designing, Objectives : At the end of this lesson you shall be able to, • explain web sites and web pages, • explain static and dynamic web pages, • explain HTML, DHTML and XML, • explain the concept of web hosting, web server, application server and database server., Introduction, The World Wide Web (WWW) was created in 1990 by, CERN physicist Tim Berners-Lee. On 30 April 1993,, CERN announced that the World Wide Web would be, free to use for anyone. Before the introduction of HTML, and HTTP, other protocols such as File Transfer Protocol, and the Gopher Protocol were used to retrieve individual, files from a server. These protocols offer a simple directory, structure which the user navigates and chooses files to, download. Documents were most often presented as plain, text files without formatting, or were encoded in word, processors formats., Websites, A website, also written as Web site, web site, or simply, site, is a set of related web page containing content, (media) such as written language, Image, video, sound,, etc. A website is hosted on at least one web server,, accessible via a network such as the internet or a private, local area network through an Internet address known, as a uniform resource locator. All publicly accessible, websites collectively constitute the world wide web., A webpage is a document, typically written in plain text, interspersed with formatting instructions of Hypertext, Mark-up Language (HTML) XHTML. A webpage may, incorporate elements from other websites with suitable, HTML anchor., Web pages are accessed and transported with the, Hypertext Transfer Protocol (HTTP), which may optionally, employ encryption secure, HTTPS to provide security and, privacy for the user of the webpage content. The user's, application, often a web browser, renders the page content, according to its HTML Mark-up instructions onto a, Computer monitor., The pages of a website can usually be accessed from a, simple Uniform Resource Locator (URL) called the web, address. The URLs of the pages organize them into a, hierarchy, although hyperlink between them conveys the, reader's perceived sitemap and guides the reader's, navigation of the site which generally includes a Home, page with most of the links to the site's web content, and, a supplementary about page, contact page and link page., , 214, , Some websites require a subscription to access some or, all of their content. Examples of subscription websites, include many business sites, parts of news websites,, Academic journal websites, gaming websites, file-sharing, websites, Internet forum, web-based Email, Social, networking websites, websites providing real-time Stock, market data, and websites providing various other, services (e.g., websites offering storing and/or sharing, of images, files and so forth)., A website may be, •, , Personal website, , •, , Commercial website, , •, , E-Government, , •, , Non-profit organization website., , Static Website, A static website is one that has web pages stored on the, server in the format that is sent to a client web browser. It, is primarily coded in Hypertext Markup Language (HTML)., Simple forms or marketing examples of websites, such, as classic website, a five-page website or a brochure, website are often static websites, because they present, pre-defined, static information to the user. This may, include information about a company and its products, and services through text, photos, animations, audio/video, and interactive menus and navigation., This type of website usually displays the same information, to all visitors. Similar to handing out a printed brochure to, customers or clients, a static website will generally provide, consistent, standard information for an extended period of, time. Although the website owner may make updates, periodically, it is a manual process to edit the text, photos, and other content and may require basic website design, skills and software., Advantages, •, , Static Websites are easier to develop, , •, , Can be developed quickly, , •, , They are indexed easily by search engines as all the, web pages actually exist on the server, which is not, the case with dynamic websites., , Copyright @ NIMI Not to be Republished
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Disadvantages, , •, , Content Site: these sites create and sell of original, content to end-user. (e.g., Slate, About.com)., , •, , Static websites cannot do complex tasks required by, many online services., , •, , •, , Updating a whole site can be cumbersome and time, consuming., , Corporate website: used to provide information regarding, business, organization, or service., , •, , •, , An isolation of Data and Design is not provided in static, websites., , Commerce site (or eCommerce site): these sites are, designed for purchasing or selling goods, such as, Amazon.com, CSN Stores, and Overstock.com., , •, , Community site: sites where persons with similar, interests communicate to each other through chatting, and messaging or through soci message boards, such, as MySpace or Facebook., , •, , City Site: A site that shows information about a certain, city or town and events that takes place in that town., Usually created by the city council. For example,, Richmond.com is the geodomain for Richmond,, Virginia., , •, , Information site: contains content that is intended to, inform visitors, but not necessarily for commercial, purposes, such as: RateMyProfessors.com, Free, Internet Lexicon and Encyclopaedia. Most, government, educational and non-profit institutions, have an informational site., , •, , Mirror site: A complete reproduction of a website., , •, , News site: similar to an information site, but dedicated, to dispensing news and commentary., , •, , Personal homepage: run by an individual or a small, group such as a family that contains information or, any content that the individual wishes to include. These, are usually uploaded using a web hosting service such, as Geocities., , •, , Phish Site: a website created to fraudulently acquire, sensitive information, such as passwords and credit, card details, by disguising as a trustworthy person or, business (such as Social Security Administration,, PayPal) in an electronic communication., , •, , Political site: A site on which people may voice political, views., , •, , Rating site: A site on which people can praise or, disparage what is featured., , •, , Review site: A site on which people can post reviews, for products or services., , •, , School site: a site on which teachers, students, or, administrators can post information about current, events at or involving their school., , •, , Video sharing: A site that enables user to upload, videos, such as YouTube and Google Video., , •, , Search engine site: a site that provides general, information and is intended as a gateway for retrieving, other sites. Google, Yahoo and MSN are the most, widely known search engines., , •, , Shock site: includes images or other material that is, intended to be offensive to most viewers (e.g., rotten.com)., , Dynamic Website, A dynamic website is one that changes or customizes, itself frequently and automatically, based on certain, criteria., Dynamic websites can have two types of dynamic activity:, Code and Content. Dynamic code is invisible or behind, the scenes and dynamic content is visible or fully displayed, Advantages, •, , Can do more complex task required by online services., , •, , They are easier to update., , •, , Isolation of data and design allows programmers and, content writers to work independently., , Disadvantages, •, , Can take more time to build., , •, , Can be difficult to build., , •, , Dynamic websites are not indexed by search engines, easily, since they do not have actual web pages, present on the web server. With continuous, improvements in search engine technology, this, problem is now very much eliminated and you can, find that many dynamic websites are very well indexed, by search engines now a days., , A few such classifications are:, •, , •, , •, , Affiliate: enabled portal that renders not only its custom, CMS but also syndicated content from other content, providers for an agreed fee. There are usually three, relationship tiers. Affiliate Agencies (e.g., Commission, Junction), Advertisers (e.g., eBay) and consumer (e.g.,, Yahoo!)., Archive site: used to preserve valuable electronic, contents that are on verge of extinction. For examples:, Internet Archive, which since 1996 has preserved, billions of old and new web pages; and Google Groups,, which in early 2005 had preserved over 845,000,000, messages posted to Usenet news/discussion groups., Blog Site: sites generally used to post online diaries,, comments or views that may include discussion, forums (e.g., blogger, Xanga)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 215
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•, , Warez: a site designed to host and let users download, copyrighted materials illegally., , •, , Web portal: a site is vehicle that provides a gateway to, other resources on the Internet or an intranet., , Web Pages, A web page or webpage is a Document or information, resource that is suitable for the world wide Web and can, be accessed through a web browser and displayed on a, computer display or mobile device. This information is, usually in HTML or XHTML format, and may provide, navigation bar to other web pages via Hyper text Hyper, link. Web pages frequently subsume other resources such, as Cascading Style Sheet, Client-side-scripting and, Images into their final presentation., Web pages may be retrieved from a local computer or, from a remote Web server. The web server may restrict, access only to a private network, e.g. a corporate Intranet, or it may publish pages on the World Wide Web. Web, pages are requested and served from web. Web server, using Hypertext Transfer Protocol (HTTP)., Web pages may consist of files of static text and other, Web content stored within the Web server 's file, system(Static Web page), or may be constructed by, Server-side scripting when they are requested (Dynamic, web page). Client-side scripting can make web pages more, responsive to user input once on the client browser., , Web Browser, A Web browser can have a Graphical User Interface, like, Internet Explorer, Mozilla Firefox, Google Chrome and, Opera (web browser), or can be Command Line Interface,, like Lynx (web browser) (Fig 1) or Links (web browser)., Web users with disabilities often use assistive, technologies and adaptive strategies to Web accessibility, web pages. Users may be colour blind, may or may not, want to use a mouse perhaps due to repetitive stress, injury or motor-neurone problems, may be deaf and, require audio to be captioned, may be blind and using a, Screen reader or display, may need screen magnification,, etc. Disabled and able-bodied users may disable the, download and viewing of images and other media, to, save time, network bandwidth or merely to simplify their, browsing experience., Users of mobile devices often have restricted displays and, bandwidth. Anyone may prefer not to use the fonts, font, sizes, styles and colour schemes selected by the web, page designer and may apply their own CSS styling to, the page. The World Wide Web Consortium (W3C) and, Web Accessibility Initiative (WAI) recommend that all web, pages should be designed with all of these options in mind., , Fig 1, , 216, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Downloading a Software from Internet, 1 Create a Temporary Files folder by opening My, Computer, double click on your hard drive (typically, the C: drive), then select File/New/Folder as on Fig 2., Fig 2, , 2 Type "Temporary File" and name it as on Fig 3., , Fig 3, , 3 Type "My SQL 5. 1 free download " from freeware, software website on internet., Note: As an example Choose "http://, dev.mysql.com/downloads/" select "My SQL, Community server" in download from the, opened site as on Fig 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 217
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Fig 4, , My Sql Community, , 4 Click "MySQL Community Server 5.1 " from looking for previous version option as on Fig 5, Fig 5, , 5 Choose "Windows (x86, 32-bit), MSI Installer Essentials - Recommended" and click download (Fig.6)., , 218, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 6, , Note: Save the "My SQL 5.1.63" in the created, Folder name " Temporary Folder", , documents (hypertext) and make web documents, interactive (such as with forms)., , 6 Burn the Downloaded "My SQL 5.1.63" in a CD ROM, for Installation., , HTML is a defined standard markup language. That, standard was developed by the World Wide Web, Consortium (W3C). It is based upon SGML (Standard, Generalized Markup Language). It is a language that uses, tags to define the structure of your text. Elements and, tags are defined by the < and > characters., , WEB LANGUAGES, Web languages are called as Markup languages are, designed for the processing, definition and presentation, of text. The language specifies code for formatting, both, the layout and style, within a text file. The code used to, specify the formatting are called tags, Four Types of Markup languages, 1 BML, , DHTML, Dynamic HTML is not really a new specification of HTML,, but rather a new way of looking at and controlling the, standard HTML codes and commands., When thinking of dynamic HTML, we need to remember, the qualities of standard HTML, especially that once a, page is loaded from the server, it will not change until, another request comes to the server. Dynamic HTML give, more control over the HTML elements and allows them, to change at any time, without returning to the Web server., , 2 HTML, 3 DHTML, 4 XML, BML (Better markup language), BML is essentially a simple macro language. Macros are, called blocks in BML. Blocks are defined in look files, and, are invoked in BML files. Blocks accept parameters and, are divided into several types, according to how parameters, are transmitted and how the definition of the block is able, to make use of them., HTML (Hyper text markup Language), HTML or HyperText Markup Language is the language of, the web. All web pages are written in HTML. HTML defines, the way that images, multimedia, and text are displayed, in web browsers. It includes elements to connect the, , There are four parts to DHTML:, •, •, •, •, , Document Object Model (DOM) (definition), Scripts, Cascading Style Sheets (CSS), XHTML, , DOM, The DOM is allows to access any part of Web page to, change it with DHTML. Every part of a Web page is, specified by the DOM and using its consistent naming, conventions can access them and change their properties., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 219
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Scripts, , Data binding, , Scripts written in either JavaScript or ActiveX are the two, most common scripting languages used to activate, DHTML. You use a scripting language to control the, objects specified in the DOM., , This is an IE only feature. Microsoft developed this to allow, easier access to databases from Web sites. It is very, similar to using a CGI to access a database, but uses an, ActiveX control to function., , Cascading Style Sheets, , XML, , CSS is used in DHTML to control the look and feel of the, Web page. Style sheets define the colors and fonts of, text, the background colors and images, and the, placement of objects on the page. Using scripting and, the DOM, we can change the style of various elements., , Extensible Markup Language (XML) is a markup language, that defines a set of rules for encoding documents in a, format that is bothhuman-readable and machine-readable., It is defined in the XML 1.0 Specification produced by the, W3C, and several other related specifications, all gratis, open standards. The design goals of XML emphasize, simplicity, generality, and usability over the Internet. It is a, textual data format with strong support via Unicode for the, languages of the world. Although the design of XML focuses, on documents, it is widely used for the representation of, arbitrary data structures, for example in web services, , XHTML, XHTML or HTML 4.x is used to create the page itself and, build the elements for the CSS and the DOM to work on., There is nothing special about XHTML for DHTML - but, having valid XHTML is even more important, as there, are more things working from it than just the browser., Features of DHTML, , Creating an HTML document, , There are four primary features of DHTML:, , Before start writing code to write a web page, it is a good, practice to plan ahead the appearance of the web page., An HTML document has two elements:, , 1 Changing the tags and properties, , 1 Document Content, , 2 Real-time positioning, , 2 Tags, , 3 Dynamic fonts (Netscape Communicator), 4 Data binding (Internet Explorer), Changing the tags and properties, This is one of the most common uses of DHTML. It allows, to change the qualities of an HTML tag depending on an, event outside of the browser (such as a mouse click, time,, or date, and so on). we can use this to preload information, onto a page, and not display it unless the reader clicks, on a specific link., Real-time postioning, Objects, images, and text moving around the Web page., This can allow we to play interactive games with the, readers or animate portions of the screen., Dynamic Fonts, This is a Netscape only feature. Netscape developed this, to get around the problem designers had with not knowing, what fonts would be on a reader's system. With dynamic, fonts, the fonts are encoded and downloaded with the page,, so that the page always looks how the designer intended, it to., , 220, , Document content is the information on a web page, that the user will see. That information could be text or, graphics., Tags are the HTML codes that control how the document, content will appear. The tags, in other words, will, determine whether the text will be bold, black or blue, or, of font type Time New Roman or Airal., Start Notepad, To start Notepad go to:, Start, All Programs, Accessories, Notepad, Edit Your HTML with Notepad (Fig 7), Type your HTML code into your Notepad:, Save Your HTML, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 7, , Select Save as.. in Notepad's file menu., When you save an HTML file, you can use either the .htm, or the .html file extension., Save the file in a folder that is easy to remember, , Start your web browser and open your html file from the, File, Open menu, or just browse the folder and doubleclick your HTML file., The result should look much like this: (Fig 8), , Run the HTML in Your Browser, Fig 8, , Structure of Markup Language, An HTML document has two* main parts:, 1 head. The head element contains title and meta data, of a web document., 2 body. The body element contains the information that, you want to display on a web page., , To make your web pages compatible with HTML 4, you, need to add a document type declaration (DTD) before the, HTML element. Many web authoring software add DTD, and basic tags automatically when you create a new web, page., In a web page, the first tag (specifically, <html>) indicates, the markup language that is being used for the document., The <head> tag contains information about the web page., Lastly, the content appears in the <body> tag. (Fig 9), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 221
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Fig 9, , The <!DOCTYPE> Declaration, There are many different documents on the web. A browser, can only display a document correctly, if it knows what, kind of document it is., There are also many different versions of HTML, and a, browser can only display an HTML page 100% correctly, if it knows the exact HTML version used in the page. This, is what <!DOCTYPE> is used for., , •, , Provides a title for the page when it is added to, favorites., , •, , Displays a title for the page in search-engine results., , HTML Element Syntax, •, , An HTML element starts with a start tag / opening tag, , •, , An HTML element ends with an end tag / closing tag, , •, , <!DOCTYPE> is not an HTML tag. It is an information (a, declaration) to the browser about what version the HTML, is written in., , The element content is everything between the start, and the end tag, , •, , Some HTML elements have empty content, , •, , Empty elements are closed in the start tag, , The HTML <head> Element, , •, , Most HTML elements can have attributes, , The <head> element is a container for all the head, elements. Elements inside <head> can include scripts,, instruct the browser where to find style sheets, provide, meta information, and more., The following tags can be added to the head section: <title>,, <base>, <link>, <meta>, <script>, and <style>., , HTML Headings, HTML headings are defined with the <h1> to <h6> tags., Examples, <html>, <body>, <h1>This is heading 1</h1>, , The HTML <title> Element, The <title> tag defines the title of the document., , <h2>This is heading 2</h2>, <h3>This is heading 3</h3>, , The title element is required in all HTML/XHTML, documents., , <h4>This is heading 4</h4>, , The title element:, , <h6>This is heading 6</h6>, , •, , Defines a title in the browser toolbar., , 222, , <h5>This is heading 5</h5>, </body>, </html>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 491 : Result, , Fig 10, , This is heading 1, This is heading 2, This is heading 3, This is heading 4, This is heading 5, This is heading 6, HTML Paragraphs, HTML paragraphs are defined with the <p> tag., , HTML Attributes, , <html>, , •, , HTML elements can have attributes, , <body>, , •, , Attributes provide additional information about an, element, , <p>This is a paragraph.</p>, , •, , Attributes are always specified in the start tag, , <p>This is a paragraph.</p>, , •, , Attributes come in name/value pairs like:, name="value", , <p>This is a paragraph.</p>, , </body>, </html>, , Attribute Example, , Examples, This is a paragraph., , HTML links are defined with the <a> tag. The link address, is specified in the href attribute:, , This is a paragraph., , <html>, , This is a paragraph., , <body>, , HTML Links, , <a href="http://www.yahoo.com">, , HTML links are defined with the <a> tag., , This is a link</a>, , <html>, , </body>, , <body>, , </html>, , <a href="http://www.facebook.com">, , Result, , This is a link</a>, , This is the link, , </body>, , By clicking the link yahoo home page appears (Fig 11)., , </html>, , Formatting, , Result, , Create Line Breaks - The <br /> Element:, , This is a link, By clicking the link it shows the facebook login page, HTML Images, HTML images are defined with the <img> tag., , Whenever the <br /> element, anything following it starts, on the next line. This tag is an example of an empty, element, where you do not need opening and closing tags,, as there is nothing to go in between them., , <html>, <body>, <img src="w3schools.jpg" width="104" height="142" />, </body>, </html>, Result (Fig 10), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 223
Page 492 : Fig 11, , Example:, , Soft Hyphens:, , Hello<br/>, You come most carefully upon your hour.<br/>, Thanks<br/>, , <p style="text-align: justify;"> The morbid fear of, the number 13, or triskaidekaphobia, has plagued, some important historic figures like Mahamiya and, Nanao.</p>, , Mahnaz, Result, , This will produce following result:, , Hello, You come most carefully upon your hour., Thanks, Mahnaz, , Example for soft hyphen - The morbid fear of the, number 13, or triskaidekaphobia, has plagued some, important historic figures like Mahamiya and Nanao., Preserve Formatting - The <pre> Element:, , To Become, Centring Content - The <center> Element:, You can use <center> tag to put any content in the center, of the page or any table cell., Example:, <p>This is not in the center.</p>, <center>, <p>This is in the center.</p>, </center>, This will produce following result:, This is not in the center., This is in the center., , 224, , Occasionally, you will want to allow a browser to hyphenate, long words to better justify a paragraph. For example,, consider the following code and its resulting output., , Sometimes you want your text to follow the exact format, of how it is written in the HTML document. In those cases,, you can use the preformatted tag (<pre>)., Any text between the opening <pre> tag and the closing, </pre> tag will preserve the formatting of the source, document., <pre>, function testFunction( strText ){, alert (strText), }, </pre>, This will produce following result:, function testFunction( strText ){, alert (strText), }, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 493 : Horizontal Rules - The <hr /> Element, , Underlined Text - The <u> Element:, , Horizontal rules are used to visually break up sections of, a document. The <hr> tag creates a line from the current, position in the document to the right margin and breaks, the line accordingly., , Anything that appears in a <u>...</u> element is displayed, with underline, like the word underlined here:, , For example you may want to give a line between two, paragraphs as follows:, , <p>The following word uses a <u>underlined</, u> typeface.</p>, This will produce following result:, , <p>This is paragraph one and should be on top</p>, , The following word uses a underlined typeface., , <hr />, , Strike Text - The <strike> Element:, , <p>This is paragraph two and should be at bottom</, p>, This will produce following result:, This is paragraph one and should be on top, This is paragraph two and should be at bottom, Again <hr /> tag is an example of an empty element,, where you do not need opening and closing tags, as there, is nothing to go in between them., Note: The <hr /> element has a space between, the characters hr and the forward slash. If you, omit this space, older browsers will have, trouble rendering the line break, while if you, miss the forward slash character and just use, <hr> it is not valid XHTML, Presentational Tags:, If you use a word processor, you are familiar with the, ability to make text bold, italicized, or underlined; these, are just three of the ten options available to indicate how, text can appear in HTML and XHTML., Bold Text - The <b> Element:, Anything that appears in a <b>...</b> element is displayed, in bold, like the word bold here:, <p>The following word uses a <b>bold</b>, typeface.</p>, This will produce following result:, The following word uses a bold typeface., Italic Text - The <i> Element:, Anything that appears in a <i>...</i> element is displayed, in italicized, like the word italicized here:, <p>The following word uses a <i>italicized</i>, typeface.</p>, This will produce following result:, The following word uses a italicized typeface., , Anything that appears in a <strike>...</strike> element is, displayed with strikethrough, which is a thin line through, the text:, <p>The, following, word, uses, a, <strike>strikethrough</strike> typeface.</p>, This will produce following result:, The following word uses a strikethrough typeface., Monospaced font - The <tt> Element:, The content of a <tt> element is written in monospaced, font. Most fonts are known as variable-width fonts, because different letters are of different widths (for, example, the letter m is wider than the letter i). In a, monospaced font, however, each letter is the same width., <p>The, following, word, uses, <tt>monospaced</tt> typeface.</p>, , a, , This will produce following result:, The following word uses a monospaced typeface., Superscript Text - The <sup> Element:, The content of a <sup> element is written in superscript;, the font size used is the same size as the characters, surrounding it but is displayed half a character.s height, above the other characters., <p>The, following, word, uses, <sup>superscript</sup> typeface.</p>, , a, , This will produce following result:, The following word uses a superscript typeface., Subscript Text - The <sub> Element:, The content of a <sub> element is written in subscript;, the font size used is the same as the characters surrounding, it, but is displayed half a character.s height beneath the, other characters., <p>The, following, word, uses, <sub>subscript</sub> typeface.</p>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , a, , 225
Page 494 : This will produce following result:, The following word uses a subscript typeface., Larger Text - The <big> Element:, The content of the <big> element is displayed one font, size larger than the rest of the text surrounding it., <p>The following word uses a <big>big</big>, typeface.</p>, , HTML Hyperlinks (Links), A hyperlink (or link) is a word, group of words, or image, that you can click on to jump to a new document or a new, section within the current document., When you move the cursor over a link in a Web page,, the arrow will turn into a little hand., Links are specified in HTML using the <a> tag., , This will produce following result:, , The <a> tag can be used in two ways:, , The following word uses a big typeface., , 1 To create a link to another document, by using the, href attribute, , Smaller Text - The <small> Element:, The content of the <small> element is displayed one font, size smaller than the rest of the text surrounding it., <p>The following word uses a <small>small</, small> typeface.</p>, , 2 To create a bookmark inside a document, by using, the name attribute, The HTML code for a link is simple. It looks like this:, <a href="url">Link text</a>, , This will produce following result:, , The href attribute specifies the destination of a link., , The following word uses a small typeface., , <a href="http://www.yahoo.com/">Visit yahoo</a>, , Styling HTML with CSS, , which will display like this: Visit yahoo.com, , CSS was introduced together with HTML 4, to provide a, better way to style HTML elements., , Clicking on this hyperlink will send the user to Yahoo, homepage., , CSS can be added to HTML in the following ways:, , The "Link text" doesn't have to be text. It can be an image, or any other HTML element., , •, , Inline - using the style attribute in HTML elements, , •, , Internal - using the <style> element in the <head>, section, , •, , External - using an external CSS file, , <html>, <body style="background-color:PowderBlue;">, <h1>Look! Styles and colors</h1>, <p style="font-family:verdana;color:red;">, This text is in Verdana and red</p>, <p style="font-family:times;color:green;">, This text is in Times and green</p>, <p style="font-size:30px;">This text is 30 pixels high</, p>, </body>, , HTML Links - The target Attribute, The target attribute specifies where to open the linked, document., The example below will open the linked document in a, new browser window or a new tab:, Example, <a href="http://www.yahoo.com/" target="_blank">Visit, yahoo !</a>, <html>, <body>, <a href="http://www.yahoo.com" target="_blank">Visit, yahoo.com!</a>, , </html>, , <p>If you set the target attribute to "_blank", the link will, open in a new browser window/tab.</p>, , Result:, , </body>, , Look! Styles and colors, , </html>, , This text is in Verdana and red, This text is in Times and green, This text is 30 pixels high, 226, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 495 : Result, , <img src="boat.gif" alt="Big Boat" />, , Visit yahoo.com!, , The alt attribute provides alternative information for an image, if a user for some reason cannot view it (because of slow, connection, an error in the src attribute, or if the user uses, a screen reader)., , If you set the target attribute to "_blank", the link will open, in a new browser window/tab., HTML Images - The <img> Tag and the Src Attribute, In HTML, images are defined with the <img> tag., The <img> tag is empty, which means that it contains, attributes only, and has no closing tag., To display an image on a page, you need to use the src, attribute. Src stands for "source". The value of the src, attribute is the URL of the image you want to display., Syntax for defining an image:, <img src="url" alt="some_text"/>, The URL points to the location where the image is stored., An image named "bamboo. gif", located in the "images", directory on "www.w3schools.com" has the URL: http://, www.backgroundlabs.com/index.php?search=bamboo., The browser displays the image where the <img> tag, occurs in the document. If you put an image tag between, two paragraphs, the browser shows the first paragraph,, then the image, and then the second paragraph., HTML Images - The Alt Attribute, The required alt attribute specifies an alternate text for an, image, if the image cannot be displayed., The value of the alt attribute is an author-defined text:, , HTML Images - Set Height and Width of an Image, The height and width attributes are used to specify the, height and width of an image., The attribute values are specified in pixels by default:, <img src="rose.jpg" alt="Rose" width="304" height="228", />, Note: It is a good practice to specify both the height and, width attributes for an image. If these attributes are set,, the space required for the image is reserved when the, page is loaded. However, without these attributes, the, browser does not know the size of the image. The effect, will be that the page layout will change during loading, (while the images load)., If an HTML file contains ten images - eleven files are, required to display the page right. Loading images takes, time, so my best advice is: Use images carefully., When a web page is loaded, it is the browser, at that, moment, that actually gets the image from a web server, and inserts it into the page. (Fig 12) Therefore, make sure, that the images actually stay in the same spot in relation, to the web page, otherwise your visitors will get a broken, link icon. The broken link icon is shown if the browser, cannot find the image., , Fig 12, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 227
Page 496 : <html>, , All major browsers display the text in the <th> element as, bold and centered., , <body>, , <table border="1">, , <h2>Friendship Card</h2>, <img border="0" src="/images/Rose.jpg" alt="Rose", width="304" height="228" />, , <tr>, <th>Header 1</th>, , </body>, , <th>Header 2</th>, , </html>, , </tr>, , HTML Tables, , <tr>, , Tables are defined with the <table> tag., , <td>row 1, cell 1</td>, , A table is divided into rows (with the <tr> tag), and each, row is divided into data cells (with the <td> tag). td stands, for "table data," and holds the content of a data cell. A, <td> tag can contain text, links, images, lists, forms, other, tables, etc., , <td>row 1, cell 2</td>, , Table Example, , </tr>, <tr>, <td>row 2, cell 1</td>, <td>row 2, cell 2</td>, , <table border="1">, , </tr>, , <tr>, , </table>, , <td>row 1, cell 1</td>, , How the HTML code above looks in your browser:, , <td>row 1, cell 2</td>, </tr>, <tr>, <td>row 2, cell 1</td>, , Header 1, , Header 2, , row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , <td>row 2, cell 2</td>, , HTML Unordered Lists, , </tr>, , An unordered list starts with the <ul> tag. Each list item, starts with the <li> tag., , </table>, How the HTML code above looks in a browser:, row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , HTML Tables and the Border Attribute, If you do not specify a border attribute, the table will be, displayed without borders. Sometimes this can be useful,, but most of the time, we want the borders to show., , The list items are marked with bullets (typically small black, circles)., <ul>, <li>Coffee</li>, <li>Milk</li>, </ul>, How the HTML code above looks in a browser:, , To display a table with borders, specify the border attribute:, , •, , Coffee, , <table border="1">, , •, , Milk, , <tr>, , HTML Ordered Lists, , <td>Row 1, cell 1</td>, , An ordered list starts with the <ol> tag. Each list item, starts with the <li> tag., , <td>Row 1, cell 2</td>, , The list items are marked with numbers., , </tr>, , <ol>, , </table>, , <li>Coffee</li>, , HTML Table Headers, Header information in a table are defined with the <th>, tag., , <li>Milk</li>, </ol>, How the HTML code above looks in a browser:, 1 Coffee, , 228, , 2 Milk, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 497 : HTML Definition Lists, A definition list is a list of items, with a description of each, item., , When used together with CSS, the <div> element can be, used to set style attributes to large blocks of content., , The <dl> tag is used in conjunction with <dt> (defines the, item in the list) and <dd> (describes the item in the list):, , Another common use of the <div> element, is for document layout. It replaces the "old way" of defining layout, using tables. Using tables is not the correct use of the, <table> element. The purpose of the <table> element is, to display tabular data., , <dl>, , The HTML <span> Element, , <dt>Coffee</dt>, , The HTML <span> element is an inline element that can, be used as a container for text., , The <dl> tag defines a definition list., , <dd>- black hot drink</dd>, <dt>Milk</dt>, <dd>- white cold drink</dd>, </dl>, How the HTML code above looks in a browser:, Coffee - black hot drink, Milk- white cold drink, Note : Inside a list item you can put text, line, breaks, images, links, other lists, etc., , The <span> element has no special meaning., When used together with CSS, the <span> element can, be used to set style attributes to parts of the text., HTML Grouping Tags, Tag, , Description, , <div>, , Defines a div, , <span>, , Defines a span, , HTML Layout, Website Layouts, , HTML List Tags, Tag, , Description, , <ol>, , Defines an ordered list, , <ul>, , Defines an unordered list, , <li>, , Defines a list item, , <dl>, , Defines a definition list, , <dt>, , Defines an item in a definition list, , <dd>, , Defines a description of an item in a, definition list, , HTML elements can be grouped together with <div> and, <span>, , Most websites have put their content in multiple columns, (formatted like a magazine or newspaper)., Multiple columns are created by using <div> or <table>, elements. CSS are used to position elements, or to create backgrounds or colorful look for the pages., HTML Layouts - Using <div> Elements, The div element is a block level element used for grouping, HTML elements., The following example uses five div elements to create a, multiple column layout, creating the same result as in the, previous example:, Example, , HTML Block Elements, , <div>, , Most HTML elements are defined as block level elements, or as inline elements., , <!DOCTYPE html>, , Block level elements normally start (and end) with a new, line when displayed in a browser., , <body>, , Examples: <h1>, <p>, <ul>, <table>, HTML Inline Elements, Inline elements are normally displayed without starting a, new line., Examples: <b>, <td>, <a>, <img>, The HTML <div> Element, The HTML <div> element is a block level element that can, be used as a container for grouping other HTML elements., The <div> element has no special meaning. Except that,, because it is a block level element, the browser will display a line break before and after it., , <html>, <div id="container" style="width:500px">, <div id="header" style="background-color:#FFA500;">, <h1 style="margin-bottom:0;">Main Title of Web Page</, h1></div>, <divid="menu"style="backgroundcolor:#FFD700;height:200px;width:100px;float:left;">, <b>Menu</b><br />, HTML<br />, CSS<br />, JavaScript</div>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 229
Page 498 : <div, id="content", style="backgroundcolor:#EEEEEE;height:200px;width:400px;float:left;">, Content goes here</div>, <div, id="footer", style="backgroundcolor:#FFA500;clear:both;text-align:center;">, , </div>, </div>, </body>, </html>, Result (Fig 13), , Fig 13, , HTML Forms, , First name: <input type="text" name="firstname" /><br />, , HTML forms are used to pass data to a server., , Last name: <input type="text" name="lastname" />, , A form can contain input elements like text fields,, checkboxes, radio-buttons, submit buttons and more. A, form can also contain select lists, textarea, fieldset, legend, and label elements., , </form>, , The <form> tag is used to create an HTML form:, , Last name:, , <form>., , How the HTML code above looks in a browser:, First name:, , Note: The form itself is not visible. Also note, that the default width of a text field is 20, characters., , input elements., </form>, HTML Forms - The Input Element, , Password Field, , The most important form element is the input element., , <input type="password" /> defines a password field:, , The input element is used to select user information., , <form>, , An input element can vary in many ways, depending on, the type attribute. An input element can be of type text, field, checkbox, password, radio button, submit button,, and more., , Password: <input type="password" name="pwd" />, , The most used input types are described below., , Password:, , Text Fields, <input type="text" /> defines a one-line input field that a, user can enter text into:, , </form>, How the HTML code above looks in a browser:, , Note: The characters in a password field are, mased (shown as asterisks or circles), , <form>, , 230, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Radio Buttons, <input type="radio" /> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of, choices:, <form>, , If you type some characters in the text field above, and, click the "Submit" button, the browser will send your input, to a page called "html_form_action.asp". The page will, show you the received input., HTML Iframes, , <input type="radio" name="sex" value="male" /> Male<br/>, <input type="radio" name="sex" value="female" /> Female, </form>, How the HTML code above looks in a browser:, , Syntax for adding an iframe:, <iframe src="URL"></iframe>, The URL points to the location of the separate page., , Male, , Iframe - Set Height and Width, , Female, , The height and width attributes are used to specify the, height and width of the iframe., , Checkboxes, <input type="checkbox" /> defines a checkbox., Checkboxes let a user select ONE or MORE options of a, limited number of choices., <form>, <input type="checkbox" name="vehicle" value="Bike" />, I have a bike<br />, <input type="checkbox" name="vehicle" value="Car" /> I, have a car, , The attribute values are specified in pixels by default, but, they can also be in percent (like "80%")., Example, <!DOCTYPE html>, <html>, <body>, <iframe src="demo_iframe.htm", height="200"></iframe>, , width="200", , </body>, , </form>, How the HTML code above looks in a browser:, , </html>, It will appear as shown in Fig 14., , I have a bike, , Iframe - Remove the Border, , I have a car, , The frameborder attribute specifies whether or not to display, a border around the iframe., , Submit Button, <input type="submit" /> defines a submit button., A submit button is used to send form data to a server. The, data is sent to the page specified in the form's action, attribute. The file defined in the action attribute usually, does something with the received input:, <form name="input" action="html_form_action.asp", method="get">, Username: <input type="text" name="user" />, <input type="submit" value="Submit" />, , Set the attribute value to "0" to remove the border:, Example, <iframe src="demo_iframe.htm" frameborder="0"></, iframe>, Use iframe as a Target for a Link, An iframe can be used as the target frame for a link., The target attribute of a link must refer to the name attribute, of the iframe:, , </form>, How the HTML code above looks in a browser:, Username:, , Submit, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 231
Page 500 : Fig 14, , Example, , HTML Colour, , <iframe src="demo_iframe.htm" name="iframe_a"></, iframe>, < p > < a h r e f = " h t t p : / / w w w. y a h o o . c o m ", target="iframe_a">yahoo.com</a></p>, HTML iframe Tag, , Color Values, HTML colors are defined using a hexadecimal notation, (HEX) for the combination of Red, Green, and Blue color, values (RGB)., The lowest value that can be given to one of the light sources, is 0 (in HEX: 00). The highest value is 255 (in HEX: FF)., , Tag, , Description, , HEX values are specified as 3 pairs of two-digit numbers,, starting with a # sign., , <iframe>, , Defines an inline sub window (frame), , Color Values (Fig 15), , Fig 15, , Color, , Color HEX, , Color RGB, , #000000, , rgb(0,0,0), , #FF0000, , rgb(255,0,0), , #00FF00, , rgb(0,255,0), , #0000FF, , rgb(0,0,255), , #FFFF00, , rgb(255,255,0), , #00FFFF, , rgb(0,255,255), , #FF00FF, , rgb(255,0,255), , #C0C0C0, , rgb(192,192,192), , #FFFFFF, , rgb(255,255,255), , <!DOCTYPE html>, , Color set by using hex value, , <html>, , </p>, , <body>, , <p style="background-color:rgb(255,255,0)">, , <p style="background-color:#FFFF00">, , Color set by using rgb value, , 232, , </p>, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 501 : <p style="background-color:yellow">, Color set by using color name, </p>, </body>, , <noscript>Sorry, your browser does not support, JavaScript!</noscript>, <p>A browser without support for JavaScript will show the, text in the noscript element.</p>, </body>, , </html>, , </html>, , Result, Color set by using hex value, Color set by using rgb value, Color set by using color name, DHTML, The HTML script Element, The <script> tag is used to define a client-side script,, such as a JavaScript., The script element either contains scripting statements, or it points to an external script file through the src attribute., The required type attribute specifies the MIME type of the, script., Common uses for JavaScript are image manipulation, form, validation, and dynamic changes of content., The script below writes Hello World! to the HTML output:, Example, <script type="text/javascript">, document.write("Hello World!"), </script>, The HTML noscript Element, The <noscript> tag is used to provide an alternate content, for users that have disabled scripts in their browser or, have a browser that doesn't support client-side scripting., The noscript element can contain all the elements that, you can find inside the body element of a normal HTML, page., The content inside the noscript element will only be, displayed if scripts are not supported, or are disabled in, the user's browser:, Example, , Result, Hello World!, A browser without support for JavaScript will show the text, in the noscript element., HTML Script Tags, Tag, , Description, , <script>, , Defines a client-side script, , <noscript>, , Defines an alternate content for users, that do not support client-side scripts, , HTML Entities, Some characters are reserved in HTML., It is not possible to use the less than (<) or greater than, (>) signs in your text, because the browser will mix them, with tags., To actually display reserved characters, we must use, character entities in the HTML source code., A character entity looks like this:, &entity_name;, OR, &#entity_number;, Non-breaking Space, A common character entity used in HTML is the nonbreaking space ( )., Browsers will always truncate spaces in HTML pages. If, you write 10 spaces in your text, the browser will remove, 9 of them, before displaying the page. To add spaces to, your text, you can use the character entity., HTML Useful Character Entities, , <!DOCTYPE html>, , Note: Entity names are case sensitive!, , <html>, <body>, <script type="text/javascript">, , HTML Uniform Resource Locators, , document.write("Hello World!"), , A URL is another word for a web address., , </script>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 233
Page 502 : Result, , URL - Uniform Resource Locator, , Entity, Name, , Entity, Number, , non-breaking, space, , , ,  , , When you click on a link in an HTML page, an underlying, <a> tag points to an address on the world wide web., , <, , less than, , <, , <, , A Uniform Resource Locator (URL) is used to address a, document (or other data) on the world wide web., , >, , greater than, , >, , >, , Explanation:, , &, , ampersand, , &, , &, , •, , Scheme - defines the type of Internet service. The, most common type is http, , ¢, , cent, , ¢, , ¢, , •, , £, , pound, , £, , £, , Host - defines the domain host (the default host for, http is www), , ¥, , yen, , ¥, , ¥, , •, , Domain - defines the Internet domain name, like, w3schools.com, , •, , euro, , €, , €, , •, , §, , section, , §, , §, , Port - defines the port number at the host (the default, port number for http is 80), , ©, , copyright, , ©, , ©, , •, , ®, , registered, trademark, , ®, , ®, , Path - defines a path at the server (If omitted, the, document must be stored at the root directory of the, web site), , •, , Filename - defines the name of a document/resource, , trademark, , ™, , ™, , Description, , ™, , Common URL Schemes, , A URL can be composed of words, such as, "w3schools.com", or an Internet Protocol (IP) address:, 192.68.20.50. Most people enter the name of the website, when surfing, because names are easier to remember than, numbers., Scheme, , The table below lists some common schemes:, , Short for...., , Which pages will the scheme be used for..., , http, , HyperText Transfer Protocol, , Common web pages starts with http://. Not encrypted, , https, , Secure HyperText Transfer, Protocol, , Secure web pages. All information exchanged are encrypted, , ftp, , File Transfer Protocol, , For downloading or uploading files to a website. Useful for, domain maintenance, , file, , A file on your computer, , URL Encoding, , XML Structure, , URLs can only be sent over the Internet using the ASCII, character-set., , The XML structure including the document parts, the, prologue, and provides a simple XML example document., , Since URLs often contain characters outside the ASCII, set, the URL has to be converted into a valid ASCII format., , Document Parts, , URL encoding replaces non ASCII characters with a "%", followed by two hexadecimal digits., , •, , Prolog, , •, , Document Element (root element), , URLs cannot contain spaces. URL encoding normally, replaces a space with a + sign., 234, , The Prologue, The prologue, equivalent to the header in HTML, may, include the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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•, , •, , •, , An XML declaration (optional) such as:, , TYPES OF Web Hosting, , <?xml version="1.0"?>, , There are four types of Web hosting, , A DTD or reference to one (optional). An example, reference to an external DTD file:, , 1 Free hosting, 2 Dedicated hosting, , <!DOCTYPE LANGLIST SYSTEM "langlist.dtd">, , 3 Shared (Virtual) hosting, , Processing instructions - An example processing, instruction that causes style to be determined by a, style sheet:, , 4 Collocated Hosting, , <?xml-stylesheettype="text/css", href="xmlstyle.css"?>, An XML Example, Therefore a complete well formed XML document may look, like:, <?xml version="1.0"?>, <LAND>, <FOREST>, <TREE>Oak</TREE>, <TREE>Pine</TREE>, <TREE>Maple</TREE>, </FOREST>, <MEADOW>, <GRASS>Bluegrass</GRASS>, <GRASS>Fescue</GRASS>, , Free hosting, Free web hosting is best suited for small sites with low, traffic, like personal sites. It is not recommended for high, traffic or for real business. Technical support is often, limited, and technical options are few., Dedicated Hosting, With dedicated hosting, your web site is hosted on a, dedicated server. Dedicated hosting is the most expensive, option. This option is best suited for large web sites with, high traffic, and web sites that use special software., Dedicated hosting to be very powerful and secure, with, almost unlimited software solutions., Shared (Virtual) Hosting, Shared hosting is very cost effective., With shared hosting, your web site gets its own domain, name, and is hosted on a powerful server along with maybe, 100 other web sites. Shared solutions often offer multiple, software solutions like e-mail, database, and different editing, options. Technical support tends to be good., Collocated Hosting, , Result, , Collocation means "co-location". Collocated hosting lets, place own web server on the premises (locations) of a, service provider. This is pretty much the same as running, own server in your own office, only that it is located at a, place better designed for it. Most likely an ISP will have, dedicated resources like high-security against fire and, vandalism, regulated backup power, dedicated Internet, connections and more., , Oak Pine Maple Bluegrass Fescue Rye, , Web Server, , <GRASS>Rye</GRASS>, </MEADOW>, </LAND>, The LAND element, above, is the root element., , Web Elements, A web page, as an information set, can contain numerous, types of information, which is able to be seen, heard or, interact by the End-user, Web Hosting, A web hosting service is a type of Internet hosting service, that allows individuals and organizations to make their, Website accessible via the World Wide Web. Web hosts, are companies that provide space on a Server (computing), owned or leased for use by clients, as well as providing, Internet connectivity, typically in a data centre. Web hosts, can also provide data centre space and connectivity to, the Internet for other servers located in their data centre,, called Collocation., , A Web server is a program that, using the client server, model and the World Wide Web's Hypertext Transfer, Protocol ( HTTP), serves the files that form Web pages to, Web users (whose computers contain HTTP clients that, forward their requests). Every computer on the Internet, that contains a Web site must have a Web server program., Two leading Web servers are Apache, the most widelyinstalled Web server, and Microsoft's Internet Information, Server (IIS). Other Web servers include Novell's Web Server, for users of its Netware operating system and IBM's family, of Lotus Domino servers, primarily for IBM's OS390 and, AS-400 customers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 235
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Web servers often come as part of a larger package of, Internet- and intranet-related programs for serving e-mail,, downloading requests for File Transfer Protocol (FTP) files,, and building and publishing Web pages. Considerations, in choosing a Web server include how well it works with, the operating system and other servers, its ability to handle, server-side programming, security characteristics, and, publishing, search engine, and site building tools that may, come with it., , Application Server, Also called an appserver, and application server (Fig 16), is a program that handles all application operations, between users and an organization's backend business, applications or database. An application server is typically, used for complex transaction-based applications. To, support high-end needs, an application server has to have, built-in redundant, monitor for high-availability, highperformance distributed application services and support, for complex database access., , Fig 16, , Database Server, Database server (Fig 17) is the term used to refer to the, back-end system of a database application using client-, , 236, , server architecture. The back-end, sometimes called a, database server, performs tasks such as data analysis,, storage, data manipulation, archiving, and other non-user, specific tasks., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Designing Static WebPages, , Related Theory for Exercise 1.12.93, , Introduction to CMS and web authoring tools, Objectives: At the end of this lesson you shall be able to, • explain the meaning of content management System., • list some of the popular CMSes., • explain the use and main features of kompozer web authoring tool., Definition of CMS:, , •, , CMS Stands for "Content Management System." A CMS, is a software tool that allows you to create, edit, and publish content., , Weebly - a web-based platform for building simple personal and business websites, , •, , Wix - a collection of web publishing tools for creating a, highly customizable website, , Description of CMS:, The goal of a CMS is to provide an intuitive user interface, for building and modifying webpage content. Each CMS, also provides a web publishing tool that allows one or more, users to publish updates live on the Web. The editing component is called the content management application, (CMA), while the publishing tool is called the content delivery application (CDA). These two components are integrated together in a CMS to streamline the web development process., In terms of web publishing, content can be simple text,, photos, music, video, documents, or just about anything, you can think of. While early CMS software was used to, manage documents and local computer files, most CMS, systems are now designed exclusively to manage content on the Web. A major advantage of using a CMS is, that it requires almost no technical skill or knowledge to, manage., Content management systems are available as installable, applications and web-based user interfaces. The use of a, web interfacesimplifies the website updating process., Additionally, most web-based CMSes are updated automatically, ensuring all users have the latest tools to manage their content., A major advantage of using a CMS is that it requires almost no technical skill or knowledge to manage. Since, the CMS manages all your content, you don't have to., There are several web-based CMS tools available today., The following are some of the most popular ones:, •, , WordPress - free web software designed for creating, template-based websites or blogs, , •, , Blogger - Google's blogging tool designed specifically, for maintaining a blog, , •, , Joomla - a flexible web publishing tool that supports, custom databases and extensions, , •, , Drupal - an open source platform often used for developing community-based sites, , Introduction to WSYIWYG web authoring tools, WYSIWYG stands for "What You See Is What You Get"., In such editors you edit not directly the source code of, your documents, but its presentation as it will appear in, the final document. So instead of writing blocks of code, manually (as you e.g. would do it in Word or Notepad),, you manipulate with design components using an editor, window. This means that you view something very similar, to the final result while the document or image is being, created., There are many easy-to-use WYSIWYG programs having, all the tools needed to create a complex and fully functional websites, even by beginners. These sites even have, options to work with HTML code be it design or editing.It, is easier to create a Web site with an HTML editor, as, software developers continue to add tools that let you develop advanced features with style.Many WSYIWYG web, authoring tools offer advanced features to integrate Dynamic HTML or many other features into a site with an, elegant and consistent design., Introduction to Kompozer, KompoZer is a complete Web Authoring System that combines web file management and easy-to-use, WYSIWYGweb page editing capabilities found in Microsoft, FrontPage, Adobe DreamWeaver and other high end programs. With kompozer you can create web pages and, manage a website with no technical expertise or knowledge of HTML., A useful feature of Kompozer is that you can use it to, publish your web pages to a web hosting server. You just, need to know your FTP account username and password, as well as the site URL and Kompozer will log in and, place your web pages on the server., KompoZer's File Menu contains menu items for all major, operations possible while using it. KompoZer's tool bar, user interface consists of:, , Copyright @ NIMI Not to be Republished, , 237
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Composition Toolbar, , •, , Format Toolbar, , •, , Tab Browser Toolbar, , •, , Edit Mode Toolbar, , •, , Status Toolbar, , Edit Mode Toolbar(Refer Fig.4), The Edit Mode Toolbar indicates the viewing mode which, is presently active for the current document. Available viewing modes are the Normal view, HTML Tags view, HTML, source view and the Preview mode. You can easily change, your viewing mode by simply clicking any of the other, three with the mouse., , Composition Toolbar, The Composition Toolbar consists of buttons for the most, used major operations. Below is the a snapshot of the, default Composition Toolbar with text below each button, indicating the respective button's function. (Refer Fig.1), copa 1308201, , Fig 1, , Format Toolbar(Refer Fig.2), , copa 1308204, , Status Toolbar(Refer Fig.5), KompoZer's status bar shows the position of the cursor, with respect to the HTML tag hierarchy. You can easily, edit/assign the properties of any particular tag in the status bar just by right clicking and choosing the desired, option. Simple left-click of the mouse on a tag in status, bar selects the text surrounded by that tag., Fig 5, , copa 1308202, , The Format Toolbar is a very useful tool while editing web, pages with KompoZer. With the Format Toolbar you can, apply paragraph format, choose a font, change foreground, or background colour, increase or decrease size, and, emphasize a block of text. You can also create ordered or, unordered lists and justify a block of text to left, right or, centre. To know which button does what just hover your, mouse over the button and a tool tip will appear indicating, the function of the button., , Fig 4, , Fig 2, , Tab Browser Toolbar(Refer Fig.3), KompoZer allows you to simultaneously edit multiple web, documents using different tabs for each opened document., Having multiple tabs gives a cleaner look to your desktop, as it is not cluttered when multiple windows are used for, each document. As a visual indicator a "red floppy icon", icon appears for pages which have been edited but not, saved yet., Fig 3, copa 1308203, , 238, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.93, , Copyright @ NIMI Not to be Republished, , copa 1308205, , •
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COMPUTER OPERATOR AND, PROGRAMMING ASSISTANT, NSQF LEVEL - 4, , 1ST Semester, TRADE THEORY, SECTOR: IT & ITES, , DIRECTORATE GENERAL OF TRAINING, MINISTRY OF SKILL DEVELOPMENT & ENTREPRENEURSHIP, GOVERNMENT OF INDIA, , NATIONAL INSTRUCTIONAL, MEDIA INSTITUTE, CHENNAI, Post Box No. 3142, CTI Campus, Guindy, Chennai - 600 032, (i), , Copyright @ NIMI Not to be Republished
Page 508 : Sector, , : IT & ITES, , Duration : 1 - Year, Trade, , Copyright, , : Computer Operator and Programming Assistant 1st Semester - Trade Theory, NSQF level 4, , 2018 National Instructional Media Institute, Chennai, , First Edition :, Second Edition :, , September 2018, December 2018, , Copies : 1,000, Copies :1,000, , Rs. 255 /-, , All rights reserved., No part of this publication can be reproduced or transmitted in any form or by any means, electronic or mechanical, including, photocopy, recording or any information storage and retrieval system, without permission in writing from the National, Instructional Media Institute, Chennai., , Published by:, NATIONAL INSTRUCTIONAL MEDIA INSTITUTE, P. B. No.3142, CTI Campus, Guindy Industrial Estate,, Guindy, Chennai - 600 032., Phone : 044 - 2250 0248, 2250 0657, 2250 2421, Fax : 91 - 44 - 2250 0791, email :
[email protected],
[email protected], Website: www.nimi.gov.in, (ii), , Copyright @ NIMI Not to be Republished
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FOREWORD, , The Government of India has set an ambitious target of imparting skills to 30 crores people, one out of every, four Indians, by 2020 to help them secure jobs as part of the National Skills Development Policy. Industrial, Training Institutes (ITIs) play a vital role in this process especially in terms of providing skilled manpower., Keeping this in mind, and for providing the current industry relevant skill training to Trainees, ITI syllabus, has been recently updated with the help of Mentor Councils comprising various stakeholder's viz. Industries,, Entrepreneurs, Academicians and representatives from ITIs., The National Instructional Media Institute (NIMI), Chennai, has now come up with instructional material to, suit the revised curriculum for Computer Operator and Programming Assistant Trade Theory 1st, Semester in IT & ITES Sector . The NSQF Level - 4 Trade Theory will help the trainees to get an international, equivalency standard where their skill proficiency and competency will be duly recognized across the globe, and this will also increase the scope of recognition of prior learning. NSQF Level - 4 trainees will also get, the opportunities to promote life long learning and skill development. I have no doubt that with NSQF Level, - 4 the trainers and trainees of ITIs, and all stakeholders will derive maximum benefits from these IMPs and, that NIMI's effort will go a long way in improving the quality of Vocational training in the country., The Executive Director & Staff of NIMI and members of Media Development Committee deserve appreciation, for their contribution in bringing out this publication., Jai Hind, , RAJESH AGGARWAL, , Director General/ Addl. Secretary, Ministry of Skill Development & Entrepreneurship,, Government of India., , New Delhi - 110 001, , (iii), , Copyright @ NIMI Not to be Republished
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PREFACE, The National Instructional Media Institute (NIMI) was established in 1986 at Chennai by then Directorate, General of Employment and Training (D.G.E & T), Ministry of Labour and Employment, (now under Directorate, General of Training, Ministry of Skill Development and Entrepreneurship) Government of India, with technical, assistance from the Govt. of the Federal Republic of Germany. The prime objective of this institute is to, develop and provide instructional materials for various trades as per the prescribed syllabi under the Craftsman, and Apprenticeship Training Schemes., The instructional materials are created keeping in mind, the main objective of Vocational Training under, NCVT/NAC in India, which is to help an individual to master skills to do a job. The instructional materials are, generated in the form of Instructional Media Packages (IMPs). An IMP consists of Theory book, Practical, book, Test and Assignment book, Instructor Guide, Audio Visual Aid (Wall charts and Transparencies) and, other support materials., The trade practical book consists of series of exercises to be completed by the trainees in the workshop., These exercises are designed to ensure that all the skills in the prescribed syllabus are covered. The trade, theory book provides related theoretical knowledge required to enable the trainee to do a job. The test and, assignments will enable the instructor to give assignments for the evaluation of the performance of a trainee., The wall charts and transparencies are unique, as they not only help the instructor to effectively present a, topic but also help him to assess the trainee's understanding. The instructor guide enables the instructor to, plan his schedule of instruction, plan the raw material requirements, day to day lessons and demonstrations., IMPs also deals with the complex skills required to be developed for effective team work. Necessary care, has also been taken to include important skill areas of allied trades as prescribed in the syllabus., The availability of a complete Instructional Media Package in an institute helps both the trainer and, management to impart effective training., The IMPs are the outcome of collective efforts of the staff members of NIMI and the members of the Media, Development Committees specially drawn from Public and Private sector industries, various training institutes, under the Directorate General of Training (DGT), Government and Private ITIs., NIMI would like to take this opportunity to convey sincere thanks to the Directors of Employment & Training, of various State Governments, Training Departments of Industries both in the Public and Private sectors,, Officers of DGT and DGT field institutes, proof readers, individual media developers and coordinators, but for, whose active support NIMI would not have been able to bring out this materials., , R. P. DHINGRA, EXECUTIVE DIRECTOR, , Chennai - 600 032, , (iv), , Copyright @ NIMI Not to be Republished
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INTRODUCTION, TRADE THEORY, The manual of trade theory consists of theorectical information for the First Semester couse of the COPATrade., The contents are sequenced accoring to the practical exercise contained in the manual on Trade practical., Attempt has been made to relate the theortical aspects with the skill covered in each exercise to the extent, possible. This co-relation is maintained to help the trainees to develop the perceptional capabilities for, performing the skills., The Trade Theory has to be taught and learnt along with the corresponding exercise contained in the manual, on trade practical. The indicating about the corresponding practical exercise are given in every sheet of this, manual., It will be preferable to teach/learn the trade theory connected to each exercise atleast one class before, performing the related skills in the system lab. The trade theory is to be treated as an integrated part of each, exercise., The material is not the purpose of self learning and should be considered as supplementary to class room, instruction., TRADE PRACTICAL, The trade practical manual is intented to be used in workshop . It consists of a series of practical exercies to, be completed by the trainees during the First Semester course of the COPA trade supplemented and, supported by instructions/ informations to assist in performing the exercises. These exercises are designed, to ensure that all the skills in the prescribed syllabus are covered., The manual is divided into twelve modules to maintain completancy of leaning process in a stipulated time, basis., The skill training in the computer lab is planned through a series of practical exercises centred around some, practical project. However, there are few instance where the individual exercise does not form a part of project., While developing the practical manual a sincere effort was made to prepare each exercise which will be easy, to understand and carry out even by below average traninee. However the development team accept that there, if a scope for further improvement. NIMI, looks forward to the suggestions from the experienced training faculty, for improving the manual., , (vi), , Copyright @ NIMI Not to be Republished
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CONTENTS, Lesson No., , Title of the Lesson, , Page No., , Module 1: Safe working practices, 1.1.01 &1.1.02, , Electrical safety, , 1, , 1.1.03 & 1.1.04, , Safety practices, fire extinguishers, , 2, , Module 2: Introduction to computer components, 1.2.05, , Introduction to computers, , 7, , 1.2.06, , Introduction to CPU architecture and mother board, , 17, , Module 3: Windows operating system, 1.3.07 -1.3.11, , Windows operating system, , 25, , 1.3.12, , Handling printers, , 33, , Module 4: Computer basics and software installation, 1.4.13, , CMOS setup and windows installation, , 36, , 1.4.14 & 1.4.15, , CMOS setup and windows installation, , 38, , 1.4.16, , Troubleshooting computer, , 42, , 1.4.17, , Application Softwares, , 47, , 1.4.18 & 1.4.19, , Bluetooth devices, , 49, , 1.4.20, , DVDs, CDs and burning DVDs, , 51, , Module 5: Dos & LInux operating systems, 1.5.21, , Comand line interface with DOS, , 53, , 1.5.22, , Methods to display the contents of a text file, , 56, , 1.5.23, , Introduction to Linux operating system, , 60, , 1.5.24 - 1.5.26, , Handling commands and various editors, , 63, , 1.5.27 - 1.5.28, , Managing files and directories, , 80, , Module 6: Word Processing Software, 1.6.29, , MS word 2010 Theory, , 113, , 1.6.30 - 1.6.37, , Creating a file, save and other options, , 117, , 1.6.38, , Typing practice using open source typing tutor tools, , 123, , (vii), , Copyright @ NIMI Not to be Republished
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Lesson No., , Title of the Lesson, , Page No., , Module 7: Spread sheet Application, 1.7.39 - 1.7.41, , Introduction to MS - Excel 2010, , 124, , 1.7.42 - 1.7.46, , Functions and formulas in MS- Excel 2010, , 133, , 1.7.47 - 1.7.48, , Data validations and Table management in Ms Excel 2010, , 138, , Module 8: Image Editing, presentations, 1.8.49 - 1.8.57, , Image editing, presentations, , 145, , Module 9: Database Management Systems, 1.9.58 - 1.9.61, , Concepts of data and Databases, , 152, , 1.9.62 - 1.9.66, , Forms, quires, and reports in access, , 163, , Module 10: Networking concepts, 1.10.67 - 1.10.69, , Concepts of network and internet, , 169, , 1.10.70, , Introduction to TCP/IP, , 188, , 1.10.71 & 1.10.72, , Transmission media and network components, , 190, , 1.10.73A, , Computer name and workgroup, , 197, , 1.10.73B, , Concept of proxy server, , 200, , 1.10.74, , Video conferencing, , 202, , 1.10.75, , Network security, , 203, , Module 11: Internet Concepts, 1.11.76 & 1.11.77, , E- mail, , 205, , 1.11.78, , Chatting,video chatting and using social network sites, , 209, , 1.11.79, , Explaining threats to computers connected to Internet & process, , 210, , 1.11.80 & 1.11.81, , Outlook Express & Google+, , 213, , Module 12: Designing Static Webpages, 1.12.82 - 1.12.92, , Web designing, , 214, , 1.12.93, , Introduction to CMS and web authoring tools, , 237, , (viii), , Copyright @ NIMI Not to be Republished
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LEARNING / ASSESSABLE OUTCOME, On completion of this book you shall be able to, • Install and setup operating system and related software in a, computer., • Create, format and edit document using word processing application software., • Create, edit and develop a workbook by using spreadsheet application software., • Create and customize slides for presentation., • Create and manage database file by using MS Access, • Install, setup/ configure, troubleshoot and secure computer network including Internet., • Develop static webpages using HTML., , (ix), , Copyright @ NIMI Not to be Republished
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SYLLABUS, First Semester, Week, No., 1., , Duration: Six Month, , Ref. Learning, Outcome, , •, , Apply safe working, practices, , • Install and setup, , operating system, and related software, in a computer., , Professional Skills, (Trade Practical), with Indicative hours, , Safe working practices, Safe working practices, • Scope of the COPA trade., 1. Visit COPA Lab. of the institutes and, locate the electrical connections with • Safety rules and safety signs., computer system setup (6 hrs), • Types and working of fire, 2. Identifying safety symbols and, extinguishers., hazard identification.(4 Hrs), Introduction to Computer, 3. Practice safe methods of fire fighting in, components, case of electrical fire. (4 hrs), • Introduction to computer, 4. Use of fire extinguishers. (4 Hrs), system. Concepts of hardward, Computer components, and Software., 5. Identify computer peripherals and, •, Function of motherboard, internal components of a disassembled, components and various, desktop computer. (6 Hrs), processors., 6. Assemble components of desktop, computer. (6 Hrs), • Various Input / Output devices, in use and their features., , 2., , • Install and setup, , Using Windows Operating System, 7. Practice on Windows interface, and navigating windows. (9 Hrs), 8. Practice on managing files and, folders using removable drives. (6 Hrs), 9. Customize the desktop settings, and manage user accounts. (6 Hrs), 10. View system properties and control, panel details. (6 Hrs), 11. Work with keyboard shortcut commands., (6 Hrs), 12. Print and scan document using different, commands.(3 Hrs), , 3., , • Install and setup, , Computer basics and Software, Installation, 13. View the BIOS settings and their, modifications. (3 Hrs), 14. Install Windows OS (5 Hrs), 15. Format Hard Disk and create, partition (3 Hrs), 16. Identify and rectify common, hardware and software issues, during OS installation. (4 Hrs), 17. Install necessary application, software for Windows i.e. Office, Package, PDF Reader, Media, Player etc. (5 Hrs), 18. Configure Bluetooth and wi-fi, settings. (3 Hrs), 19. Install Drivers for printer, scanner,, webcam and DVD etc. (4 Hrs), 20. Burn data, video and audio files on, CD/DVD using application, software. (3 Hrs), , operating system, and related software, in a computer., , operating system and, and related software, in a computer., , Professional Knowledge, (Trade Theory), , COPA 1st semester, , Introduction Windows, Operating System, • Introduction to operating, System, • Main features of Windows, OS, • Concept of various shortcut, commands., , Computer basics and Software, Installation, • Introduction to the booting, process., • Introduction to various, types of memories and their, features., • Basic Hardware and, software issues and their, solutions., • Usage of Application, software and Antivirus., , Copyright @ NIMI Not to be Republished
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• Install and, , DOS Command Line Interface & Linux, Operating Systems, 21. Use basic DOS commands for directory listing (10 hrs), 22. Manage files and folders using DOS commands (6 hrs), 23. Install Linux operating system.(6 Hrs), 24. Install necessary application software for Linux i.e., Office Package, PDF Reader, MediaPlayer etc. (6 Hrs), 25. Use Basic Linux commands for directory listing, file, and folder management, password etc. (10Hrs), 26. Use the Linux GUI for file and folder management,, exploring the system etc. (10 Hrs), 27. Customize desktop settings and manage user, accounts in Linux. (6 Hrs), 28. View system properties and manage system setting, in Linux (6 Hrs), , 6-8, , Create, format, and edit, document using, word, processing, application, software., , Word Processing, Using Word Processing Software, 29. Open MS Word and familiarise with basic word Software, components. (3 Hrs), • Introduction to the various, 30. Practice creating, saving and renaming of word, applications in MS office., documents.(3 Hrs), • Introduction to Word, 31. Edit document using basic formatting tools. (8 Hrs), features,, 32. Practice Inserting and formatting tables and other, Office button, toolbars., objects. (12 Hrs), • Creating, saving and, 33. Work with Page layout settings and printing, formatting, documents. (6 Hrs), and printing documents, 34. Use templates, autocorrect tools, and record and, using Word., execute a macro. (6 Hrs), 35. Use Mail merge tool. Use conditional Mail Merge, • Working with objects,, macro, mail merge,, External Data Source. Practice Letters, Label &, templates and other tools, Envelop printing using Mail Merge (10 Hrs)., in Word., 36. Use Table of Context, Indexing, Hyperlink, Bookmark,, Comment, equation,symbols,citation, crossreference,, footnote, translate, synonyms, thesaurus, spell, check & grammer, compare etc. ( 6 Hrs ), 37. Practice Typing using open source tutor. (24 Hrs), 38. Practice of using shortcut keys and use Open Office, as word processor. (12 Hrs), , 9 - 11, , • Create,, , 4-5, , setup OS, and related, software in a, computer., , Introduction to DOS, Command, Line Interface & Linux, Operating, Systems, • Introduction to basic DOS, Internal and External, Commands., • Introduction to Open, Source Software., • Introduction to Linux, Operating System features,, structure,, files, and, processes., • Basic Linux commands., , Using Spread Sheet Application, Spread Sheet Application, 39. Open MS Excel and familiarise with basic application • Introduction to Excel, format,, components. (4 Hrs), edit and, features and Data Types., 40., Practice, create, save and format excel sheets. (9 Hrs), develop, • Cell referencing and, a workbook by 41. Use absolute and relative referencing, linking sheets,, linking, conditional formatting etc. (9 Hrs), using, Sheets., spreadsheet 42. Practice Excel functions of all major categories i.e. • Introduction to various, Financial, Logical, Text, date & time, Lookup, Math,, application, functions in all categories, Statistical etc. (12 Hrs), software., of Excel., 43. Use various data types in Excel, sorting, filtering and, • Concepts of sorting,, validating data. (8 Hrs), 44. Create and format various static and dynamic charts., filtering, (10 Hrs), and validating data., 45. Practice Importing & exporting excel data. (4 Hrs), • Analyzing data using, 46. Perform data analysis using “what if” tools and Pivot, charts, data tables, pivot, Table and record and execute a macro. (10 Hrs), tables, goal seek and, 47. Modify Excel page setup and printing and use open, scenarios., office as Spreadsheet application. (4 Hrs), 48. Execute simple projects using Excel & Word. (20 Hrs), , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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12 - 13, , Create and, customize, slides for, presentation., , 14 - 15, , Create and, manage, database, file by, using MS, Access., , 16 - 17, , Install,, setup/, configure,, troubleshoot, and secure, computer, network, including, Internet., , Image editing and creating, Presentations, 49. Use Windows Paint or image editing, software like Open Office Draw, GIMP,, IrfanView or a similar tool. (6 Hrs), 50. Perform Image editing using open, source applications. (12 Hrs), 51. Open power point presentation, and familiarise with basic, application components. (6 Hrs), 52. Create Slide shows, Insert picture, and theme. (6 Hrs), 53. Add new slide, format text, link with word, and excel documents. (5 Hrs), 54. Practice animating slide transitions and, objects. (4 Hrs), 55. Create slide shows by inserting audio &, video and sync with presentation. (6 Hrs), 56. Modify slide page setup and print, the slides. (3 Hrs), 57. Create a simple presentation, project using open office. (12 Hrs), Database Management with MS Access, 58. Create database and design a simple tables, in Access. (6 Hrs), 59. Practice enforcing integrity constraints and, modify properties of tables and fields. (6, Hrs), 60. Create relationships and join tables. (6 Hrs), 61. Create and format Forms. (6 Hrs), 62. Create simple queries with various criteria, and calculations. (12 Hrs), 63. Create Simple update, append, make table,, delete and crosstab queries. (9 Hrs), 64. Modify form design with controls, macros, and events. (6 Hrs), 65. Import and export data to/from Access and, create and format types of reports. (6 Hrs), 66. Compress and Encrypt databases. (3 Hrs), , Image editing, Presentations, • Introduction to Open Office., • Introduction to the, properties and editing of, images., • Introduction to different, formats of images and their, uses., • Introduction to Power Point, and its advantages., • Creating Slide Shows., • Fine tuning the, presentation and good, presentation technique., , Database Management Systems, • Concepts of Data and Databases., • Overview of popular databases,, RDBMS, OODB and NOSQL., • Rules for designing good tables., Integrity rules and constraints in, a table., • Relationships in tables., • Introduction to various types of, Queries and their uses., • Designing Access Reports and, Forms., • Introduction to macros, designer, objects controls, their properties, and behaviour., , Configuring and using Network, Networking Concepts, 67. View Network connections. (3 Hrs), • Introduction to Computer Networks,, 68. Connect a computer to a n/w and share, Necessity and Advantages., Devices i.e. Printers, files, folders and, • Client Server and peer to Peer, drives. (6 Hrs), networking concepts., 69. Work with various Network devices,, •, Concept of Proxy Server and proxy, connectors/cables. Create straight/cross, firewall server., cable and punch a UTP cable in the patch, • Concept of DHCP Server., socket and test the connectivity. (6 Hrs), 70. Practice IP Addressing and Subnet masking • Introduction to LAN, WAN and MAN., for IPV4/ IPV6 and pinging to test networks. • Network topologies. Network, (6 Hrs), components, viz. Modem, Hub,, 71. Configure Hub and Switch. (6 Hrs), Switch, Router,Bridge, Gateway etc., 72. Set up and configure wired and wireless, • Network Cables, Wirelessnetworks, LAN in a Computer Lab within at least three, and Blue Tooth technology., computers. Use patch panel & I/O Box for, •, Concept of ISO - OSI 7 Layer Model., wired LAN and installing & configuring, Internet connection in a single PC and in a • Overview of Network protocols, Viz.TCP/IP, FTP, Telnet etc., LAN. (12 Hrs), COPA1st semester, , Copyright @ NIMI Not to be Republished
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73. Setup a proxy server/DHCP Server with firewall.(9 Hrs), 74. Setup video conferencing using open source s/w(6 Hrs), 75. Use various tools (by open source /free) for network, troubleshooting, maintenance and security for both, Wired and Wireless(6 Hrs), 18, , • Concept of Logical and, , Physical Addresses,, Subnetting and Classes of, Networks., , Using Internet, Install,, Internet Concepts, 76. Browse the Internet for information (use at least 3 • Introduction to www,, setup/, popular browsers). (3 Hrs), configure,, Concept of Internet, Web, troubleshoot 77. Create and use e-mail for communication with, Browsers, internet servers, attachment, priority setting, address book. (3 Hrs), and secure, and search engines., 78. Communicate with text, video chatting and social, computer, •, Concepts of Domain naming, networking sites. (6 Hrs), network, Systems and E mail, 79. Use online dictionary, translation software, storage, including, communication., space, share files with e-mail links, download manager,, Internet., •, Introduction to video chatting, download & upload YouTube files, google map & earth, tools and Social Networking, etc. Update windows & other software. (6 Hrs), concepts., 80. Configure Outlook, mail service in mobile phones. Use, tools like Skype, Google+ etc. (6 Hrs), 81. Browser setting for Bookmark, cookies, favourites and, pop ups, default website, trusted site,restricted site,, content, history and advanced setup. (6 Hrs ), , Web Design Concepts, Designing Static Web Pages, 19-21 Develop, 82. Practice with basic HTML elements (e.g. head, title, • Concepts of Static and, static, body), tag and attributes. (3 Hrs), Dynamic Web pages., web pages, 83. Design simple web page with text, paragraph and line • Introduction to HTML and, using, break usingHTML tags. (5 Hrs), HTML., various tags in HTML., 84. Format text, change background colour and insert, • Concepts of different, pictures in web page. (6 Hrs), controls used in Web Pages., 85. Design simple web page with tables and lists. (6 Hrs), 86. Use marquees, hyperlinks and mailto link in designing • Concepts of CSS and, applying CSS to HTML., web pages.(6 Hrs), •, Introduction to open source, 87. Create frames, add style and design layout. (10 Hrs), CMS viz, Joomla, Word, 88. Insert text, check and combo box in web page. (6 Hrs), press etc. and Web, 89. Design web page using password field, submit button,, authoring tools viz., reset button and radio button etc. (6 Hrs), Kompozer, Front Page etc., 90. Design a web page adding flash file, audio and video, files. (10 Hrs), • Concept of good web page, 91. Design web page with forms and form controls using, designing techniques., HTML tags.(8 Hrs), 92. Create web page using Cascading Style Sheet (CSS)., (12 Hrs), 93. Use WYSIWYG (Kompozer) web design tools to, design and edit web pages with various styles. (12Hrs), 22-23 Industrial Visit/Project work, 1. Create a simple web site of at least 5 web pages which will include Images, tables, charts, lists and, hyperlink on any topic like Student Information System, Book Store, and Organisations etc., OR, 2. Setup and configure a LAN using at least 3 computers connected with wire and 3 computers connected, with wireless and secure it.), 24-25, 26, , Revision, Examination, , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.01 &1.1.02, , Electrical safety, Objective : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire., The severity of an electric shock will depend on the level of, current which passes through the body and the length of, time of contact. Do not delay, act at once. Make sure that, the electric current has been disconnected., , If the casualty is unconscious but is breathing, loosen the, clothing about the neck, chest and waist and place the, casualty in the recovery position.( Fig 3), , If the casualty is still in contact with the supply - break the, contact either by switching off the power, removing the plug, or wrenching the cable free. If not, stand on some insulating, material such as dry wood, rubber or plastic, or using, whatever is at hand to insulate yourself and break the, contact by pushing or pulling the person free. (Figs 1 & 2), If you remain un-insulated, do not touch the victim with your, bare hands until the circuit is made dead or person is, moved away from the equipment., , Keep a constant check on the breathing and pulse rate., Keep the casualty warm and comfortable. (Fig 4), Send for help., Do not give an unconscious person anything by, mouth., Do not leave an unconscious person unattended., If the casualty is not breathing - Act at once - don’t waste, , If the victim is aloft, measures must be taken to prevent him, from falling or atleast make him fall safe., Electric burns on the victim may not cover a big area but, may be deep seated. All you can do is to cover the area, with a clean, sterile dressing and treat for shock. Get, expert help as quickly as possible., , Copyright @ NIMI Not to be Republished, , 1
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.03 & 1.1.04, , Safety practice - fire extinguishers, Objectives : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire, • distinguish the different types of fire extinguishers, • determine the correct type of fire extinguisher to be used based on the class of fire, • describe the general procedure to be adopted in the event of a fire., Fire is the burning of combustible material. A fire in an, unwanted place and on an unwanted occasion and in an, uncontrollable quantity can cause damage or destroy, property and materials. It might injure people, and, sometimes cause loss of life as well. Hence, every effort, must be made to prevent fire. When a fire outbreak is, discovered, it must be controlled and extinguished by, immediate corrective action., Is it possible to prevent fire? Yes, fire can be prevented by, eliminating anyone of the three factors that causes fire., The following are the three factors that must be present in, combination for a fire to continue to burn. (Fig 1), , Accumulation of combustible refuse (cotton waste soaked, with oil, scrap wood, paper, etc.) in odd corners are a fire, risk. Refuse should be removed to collection points., The cause of fire in electrical equipment is misuse or, neglect. Loose connections, wrongly rated fuses, overloaded, circuits cause overheating which may in turn lead to a fire., Damage to insulation between conductors in cables causes, fire., Clothing and anything else which might catch fire should be, kept well away from heaters. Make sure that the heater is, shut off at the end of the working day., Highly flammable liquids and petroleum mixtures (thinner,, adhesive solutions, solvents, kerosene, spirit, LPG gas, etc.) should be stored in the flammable material storage, area., Blowlamps and torches must not be left burning when they, are not in use., Extinguishing fires: Fires are classified into four types in, terms of the nature of fuel., , Fuel: Any substance, liquid, solid or gas will burn, if there, is oxygen and high enough temperatures., Heat: Every fuel will begin to burn at a certain temperature., It varies and depends on the fuel. Solids and liquids give off, vapour when heated, and it is this vapour which ignites., Some liquids do not have to be heated as they give off, vapour at normal room temperature say 150C, eg. petrol., Oxygen: Usually exists in sufficient quantity in air to keep, a fire burning., Extinguishing of fire: Isolating or removing any of these, factors from the combination will extinguish the fire. There, are three basic ways of achieving this., •, , Starving the fire of fuel removes this element., , •, , Smothering - ie. isolate the fire from the supply of, oxygen by blanketing it with foam, sand etc., , •, , Cooling - use water to lower the temperature. Removing, any one of these factors will extinguish the fire., , Different types of fires (Fig 2, Fig 3 Fig 4 & Fig 5) have to, be dealt with in different ways and with different extinguishing, agents., An extinguishing agent is the material or substance used, to put out the fire, and is usually (but not always) contained, in a fire extinguisher with a release mechanism for spraying, into the fire., It is important to know the right type of agent for extinguishing, a particular type of fire; using a wrong agent can make, things worse.There is no classification for ‘electrical fires’, as such, since these are only fires in materials where, electricity is present., , Preventing fires: The majority of fires begin with small, outbreaks which burn unnoticed until they have a secure, hold. Most fires could be prevented with more care and by, following some simple common sense rules., 2, , Copyright @ NIMI Not to be Republished
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Fuel, , Extinguishing, Most effective ie. cooling with water. Jets of water, should be sprayed on the base of the fire and then, gradually upwards., , Should be smothered. The aim is to cover the entire, surface of the burning liquid. This has the effect of, cutting off the supply of oxygen to the fire., Water should never be used on burning liquids., Foam, dry powder or CO2 may be used on this type, of fire., , Extreme caution is necessary in dealing with liquefied, gases. There is a risk of explosion and sudden, outbreak of fire in the entire vicinity. If an appliance, fed from a cylinder catches fire - shut off the supply, of gas. The safest course is to raise an alarm and, leave the fire to be dealt with by trained personnel., Dry powder extinguishers are used on this type of, fire., , Special powders have now been developed which, are capable of controlling and/or extinguishing this, type of fire., The standard range of fire extinguishing agents is, inadequate or dangerous when dealing with metal, fires., Fire on electrical equipment., Halon, Carbon dioxide, dry powder and vapourising, liquid (CTC) extinguishers can be used to deal with, fires in electrical equipment. Foam or liquid (eg., water) extinguishers must not be used on electrical, equipment under any circumstances., , IT & ITES : COPA - Related Theory for Exercise 1.01.01 & 1.01.02, , Copyright @ NIMI Not to be Republished, , 3
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Many types of fire extinguishers are available with different, extinguishing ‘agents’ to deal with different classes of fires., (Fig 1), , Dry powder extinguishers (Fig 4): Extinguishers fitted, with dry powder may be of the gas cartridge or stored, pressure type. Appearance and method of operation is the, same as that of the water-filled one. The main distinguishing feature is the fork shaped nozzle. Powders have been, developed to deal with class D fires., , Water-filled extinguishers: There are two methods of, operation. (Fig 2), , Carbon dioxide (CO2): This type is easily distinguished, by the distinctively shaped discharge horn. (Fig 5)., , •, , Gas cartridge type, , •, , Stored pressure type, , With both methods of operation the discharge can be, interruted as required, conserving the contents and, preventing unnecessary water damage., Foam extinguishers (Fig 3):These may be of stored, pressure or gas cartridge types. Always check the operating, instructions on the extinguisher before use., , Suitable for Class B fires. Best suited where contamination, by deposits must be avoided. Not generally effective in, open air., Always check the operating instructions on the container, before use. Available with different gadgets of operation, such as - plunger, lever, trigger etc., Halon extinguishers (Fig 6): These extinguishers may be, filled with carbon-tetrachloride and Bromochlorodifluoro, methene (BCF). They may be either gas cartridge or stored, pressure type., , Most suitable for, • flammable liquid fires, •, , running liquid fires., , Must not be used on fires where electrical equipment is, involved., , 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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They are more effective in extinguishing small fires involving, pouring liquids. These extinguishers are particularly suitable, and safe to use on electrical equipment as the chemicals, are electrically non-conductive., The fumes given off by these extinguishers are, dangerous, especially in confined space., The general procedure in the event of a fire:, •, , Raise an alarm., , •, , Turn off all machinery and power (gas and electricity)., , •, , Close the doors and windows, but do not lock or bolt, them. This will limit the oxygen fed to the fire and prevent, its spreading., , •, , Try to deal with the fire if you can do so safely. Do not, risk getting trapped., , •, , Anybody not involved in fighting the fire should leave, calmly using the emergency exits and go to the, designated assembly point. Failure to do this may, mean that some person being unaccounted for and, others may have to put themselves to the trouble of, searching for him or her at risk to themselves., , Practice on fire extinguishers, Objectives: At the end of this lesson you shall be able to, • state about the selection of the fire extinguishers according to the type of fire, • state the method of operation of the fire extinguisher, • explain how to extinguish the fire., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished, , 5
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PROCEDURE (Fig 1), , •, , •, , Alert people sorrounding by shouting fire, fire, fire when, observe the fire., , •, , Inform fire service or arrange to inform immediately., , •, , Open emergency exist and ask them to go away., , •, , Put “off” electrical power supply., , Aim the extinguisher nozzle or hose at the base of the, fire (this will remove the source of fuel fire) (Fig 4), , Don’t allow people to go nearer to the fire, •, , Analyze and identify the type of fire. Refer Table1., Table-1, Class ‘A’, , Wood, paper, cloth,, solid material, , Class ‘B’, , Oil based fire (grease,, gasoline, oil) liquefiable, gases, , Class ‘C’, , Gas and liquefiable, , Keep your self low, •, , Squeeze the handle lever slowly to discharge the agent, (Fig 5), , •, , Sweep side to side approximately 15 cm over the fuel, fire until the fire is put off (Fig 5), , gases, Class ‘D’, , Metals and electrical, equipment, , Assume the fire is ‘B; type (flammable liquifable solids), •, , Slect CO2 (Carbon di oxide) fire extinguisher., , •, , Locate and pickup, CO2 fire extinguisher. Click for its, expiry date., , •, , Break the seal (Fig 2), Fire extinguishers are manufactured for use, from the distance., Caution, • While putting off fire, the fire may flare up, • Do not be panick belong as it put off promptly., • If the fire doesn’t respond well after you have, used up the fire extinguisher move away yourself, away from the fire point., , •, , Pull the safety pin from the handle (Pin located at the, top of the fire extinguisher) (Fig 3), , • Do not attempt to put out a fire where it is, emitting toxic smoke leave it for the professionals., • Remember that your life is more important than, property. So don’t place yourself or others at risk., In order to remember the simple operation of the, extinguisher. Remember P.A.S.S. This will help, you to use the fire extinguisher., P for Pull, A for Aim, S for Squeeze, S for Sweep, , 6, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.2.05, COPA - Introduction to computer components, Introduction to computers, Objectives : At the end of this lesson you shall be able to, • define and classify computers, • list the advantages and limitations of computers, • list the applications of computer, • describe the voltages and currents in the computer., Computer - Definitions, , Fig 1, , A computer is an electronic machine, operating under, the control of instructions stored in its own memory that, can accept data (input), manipulate the data according, to specified rules (process), produce results (output), and, store the results for future use., Technically, a computer is a programmable machine., This means it can execute a list of programmed, instructions and respond to new instructions that it is, given., History of Computer, Charles babbbage’s machine, , The Analytical Engine had four parts. A mill, which was, the section which did the calculations, essentially the, CPU; the store, were the information was kept recorded,, essentially the memory; the reader, which would allow, data to be entered using punched cards, essentially the, keyboard, and the printer., Hence, Charles Babbage is considered as the "Father, of the Computer" as in fig-1., The generations of computers are characterized by a, major technological development that fundamentally, changed the way computers operate, resulting in, increasingly smaller, cheaper, more powerful and more, efficient and reliable devices. The various generations, of computers are listed below:, First Generation (1946-1954): In 1946 the digital, computer using electronic valves (Vacuum tubes) are, known as first generation computers. The first 'computer', to use electronic valves i.e. vacuum tubes. The high, cost of vacuum tubes prevented their use for main, memory. They stored information in the form of, propagating sound waves., The vacuum tube consumes a lot of power. These, computers were large in size and writing programs on, them was difficult. Some of the computers of this, generation were:, , CP110111, , The working principles of today's computers were, provided by an English mathematician Charles Babbage, around 1833's invented a machine called the "Analytical, Engine". A machine which could calculate and print tables, of functions using limited techniques., , Mark I :The IBM Automatic Sequence Controlled, Calculator (ASCC), called the Mark I by Harvard, University, was an electro-mechanical computer. Mark, I is the first machine to successfully perform a long, services of arithmetic and logical operation. Mark I is, the First Generation Computer., ENIAC: It was the first electronic computer built in 1946, at University of Pennsylvania, USA by John Eckert and, John Mauchy. It was named Electronic Numerical, Integrator and Calculator (ENIAC). The ENIAC was 3050 feet long, weighted 30 tons, contained 18,000 vacuum, tubes, 70,000 resisters, 10,000 capacitors and required, 150,000 watts of electricity. Today computer is many, times as powerful as ENIAC, still size is very small., EDVAC: It stands for Electronic Discrete Variable, Automatic Computer and was developed in 1950. The, concept of storing data and instructions inside the, computer was introduced here. This allowed much faster, operation since the computer had rapid access to both, data and instructions. The other advantage of storing, instruction was that computer could do logical decision, internally. The EDVAC was a binary serial computer, with automatic addition, subtraction, multiplication,, programmed division and automatic checking with an, ultrasonic serial memory., , Copyright @ NIMI Not to be Republished, , 7
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EDSAC: It stands for Electronic Delay Storage, Automatic Computer and was developed by M.V., Wilkes at Cambridge University in 1949. The EDSAC, is the first stored-program computer. The EDSAC, performed computations in the three millisecond range., It performed arithmetic and logical operations without, human intervention. The key to the success was in the, stored instructions which it depended upon solely for its, operation., , • Transistors were used instead of Vacuum Tube., • Processing speed is faster than First Generation, Computers (Micro Second), , • Smaller in Size (51 square feet), • The input and output devices were faster., , This machine marked the beginning of the computer, age., , Third Generation (1964-1977):By the development of a, small chip consisting of the capacity of the 300 transistors., These Integrated Circuits (IC)s are popularly known as, Chips., , UNIVAC-1: It stands for Universal Automatic, computer and it was the First commercial computer, developed by United States In 1951. The machine was, 25 feet by 50 feet in length, contained 5,600 tubes, 18,000, crystal diodes, and 300 relays. It utilized serial circuitry,, 2.25 MHz bit rate, and had an internal storage capacity, 1,000 words or 12,000 characters., , A single IC has many transistors, registers and capacitors, built on a single thin slice of silicon. So it is quite obvious, that the size of the computer got further reduced. Some, of the computers developed during this period were IBM360, ICL-1900, IBM-370, and VAX-750. Higher level, language such as BASIC (Beginners All purpose, Symbolic Instruction Code) was developed during this, period., , The UNIVAC was used for general purpose computing, with large amounts of input and output. The UNIVAC, was also the first computer to come equipped with a, magnetic tape unit and was the first computer to use, buffer memory., Limitations of First Generation Computer, Followings are the major drawbacks of First generation, computers., , Computers of this generation were small in size, low cost,, large memory and processing speed is very high. Very, soon ICs were replaced by LSI (Large Scale Integration), which consisted about 100 components., An IC containing about 100 components is called LSI as, in (Fig 2)., Features, , • They used valves or vacuum tubes as their main, electronic component., , • They were large in size, slow in processing and had, less storage capacity., , • They consumed lots of electricity and produced lots, of heat., , • Their computing capabilities were limited., • They were not so accurate and reliable., • They used machine level language for programming., • They were very expensive., Second Generation (1955-1964): The second-generation computer used transistors for CPU components, and ferrite cores for main memory&magnetic disks, for secondary memory. They used high-level languages, such as FORTRAN (1956), ALGOL (1960) & COBOL, (1960 - 1961). Input Output (I/O)processor was included, to control I/O operations., Manufacturing cost was also very low. Thus the size of, the computer got reduced considerably., It is in the second generation that the concept of Central, Processing Unit (CPU), memory, programming language, and input and output units were developed. Some of the, second generation computers are IBM 1620, IBM, 1401,CDC 3600., 8, , • They used Integrated Circuit (IC) chips in place of the, transistors., , • Semi conductor memory devices were used., • The size was greatly reduced, the speed of processing, was high, and they were more accurate and reliable., , • Large Scale Integration (LSI) and Very Large Scale, Integration (VLSI) were also developed., , • The mini computers were introduced in this generation., • They used high level language for programming., Fourth Generation (1978 - present): An IC containing, about 100 components is called LSI (Large Scale, Integration) and the one, which has more than 1000 such, components, is called as VLSI (Very Large Scale, Integration)., It uses large scale Integrated Circuits(LSIC) built on a single, silicon chip called microprocessors. Due to the, development of microprocessor it is possible to place, computer's centralprocessing unit(CPU) on single chip., These computers are called microcomputers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Later very large scale Integrated Circuits(VLSIC) replaced, LSICs. Thus the computer which was occupying a very, large room in earlier days can now be placed on a table., The personal computer (PC) that you see in your school, is a Fourth Generation Computer Main memory used fast, semiconductors chips up to 4 M bits size. Some of the, Fourth generation computers are IBM PC, AppleMacintosh, etc., , Fig 3, , Hard disks were used as secondary memory. Keyboards,, dot matrix printers etc. were developed. Operating System, (OS)-such as MS-DOS, UNIX, Apple's Macintosh were, available. Object oriented language, C++ etc were, developed., Features, , • They used Microprocessor (VLSI) as their main, switching element., , • They are also called as micro computers or personal, computers., , • Their size varies from desktop to laptop or palmtop., • They have very high speed of processing; they are, 100% accurate, reliable, diligent and versatile., , • They have very large storage capacity., Fifth Generation (PRESENT AND FUTURE): 5th, generation computers use ULSI (Ultra-Large Scale, Integration) chips. Millions of transistors are placed in a, single IC in ULSI chips., 64 bit microprocessors have been developed during this, period.. Memory chips and flash memory up to 1 GB,, hard disks up to 600 GB & optical disks up to 50 GB have, been developed (fig. 3)., , CP110113, , CP110113, , Fifth generation computing devices, based on Artificial, Intelligence, are still in development, though there are some, applications, such as voice recognition, that are being used, today., Artificial Intelligence is the branch of computer science, concerned with making computers behave like humans., The term was coined in 1956 by John McCarthy at the, Massachusetts Institute of Technology. Artificial, intelligence includes:, , • Games Playing: Programming computers to play, games such as chess and checkers, , • Expert Systems: Programming computers to make, decisions in real-life situations (for example, some, expert systems help doctors diagnose diseases based, on symptoms), , • Natural Language: Programming computers to, understand natural human languages, , • Neural Networks: Systems that simulate intelligence, , by attempting to reproduce the types of physical, connections that occur in animal brains, , • Robotics: programming computers to see and hear, and react to other sensory stimuli, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 9
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Table - 1, GENERATION, , ELECTRONIC COMPONENT, , ADVANTAGES, , First, , Vaccum tube, , Helped in calculation, and computational work, , Second, , Transistor, , 1.Smaller size, 2.Less cost, 3.Better speed, 4.Low power consumption, and less heat generation, 5.Better storage capacity, 6.Better accuracy and, more reliability, , Third, , Integrated Circuits(IC), small & medium scale, , 1.Better in all aspects, 1.Initial problem withmanufaccompared to I & II, turers, 2.Used operating systems 2.No insight obtained into, and high level language, internal working, , Fourth, , VLSI or Microprocessor, , 1.Low cost, 2.Excellent speed and, reliability, 3.Computers close to man, , Fifth, (Knowledge, Information, Processing, Systems), , ULSI or Bio-Chips, , 1.Very cheap, , 1.Big size, 2.Very costly, 3.Slow speed, 4.Low accuracy, 5.Low storage, 6.High power requirements, 7.High heat generation, 8.High failure rate, 9.Used machine language, 10.No operating system, 1.Need air conditioning, 2.Constant maintenance, 3.No operating systems, 4.Later stage computers used, assembly languages, , 1.Less powerful than main, frame computers, , 1.New low level language, needed, , 2.super speeds, 3.Very high storage capacity, 4.Highly sophisticated OS, 5.posses intelligence and, decision making ability, , Classification of computers, Computers are classified according to the following criteria:, , • Principle of Operation, • Computing Power, Memory Capacity and cost, • Technological Development, • Principle of operation, , It is a computer that measures continuously changing, physical quantities such as current, temperature,, pressure etc. and converts them into quantities which, can be used as data for computation. As these computers, deal with continuously varying quantities they will give, only approximate results. Its output is usually displayed, on a meter or scale. Analog computer has low memory, and fewer functions. These are used for engineering and, scientific applications., , •, , Analog computer, , • Thermometer, , •, , Digital Computer, , • Speedometer, , •, , Hybrid Computer, , • Analog clock, , Analog Computer, 10, , DISADVANTAGES, , Digital Computer, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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A digital computer works with digital data. Digital computer, uses binary number system. Binary number system, consists of only two digits '0' and '1'. A digital computer, represents data in digital signals. A '0' represents OFF, and a '1' represents ON. Digital computer performs, arithmetic and logical operations on data. It gives output, in digital form., , store results. They have large Memory (that is data storing, capacity). Today most of the computers used in offices, and homes are Digital computers., , • Special purpose computers, , Digital computers are very fast. These computers can, , • General purpose computers, , The digital computers are further divided into the, following two groups:, , Table 2, Analog Computers, , Digital Computers, , 1. Analog Computers Work on continuous values., 2 Analog Computers have low memory., 3 Analog computers have Slow speed., , Digital computers Work on discrete values., Digital computers have a very large memory, Digital computers have fast speed., , 4 Analog computers are less reliable., , Digital computers are more reliable., , 5 Analog computers used in engineering, , Digital computers are used in all fields of life., science and medical fields., , 6 Analog computers are used to calculate /, , Digital computers are used to calculate, , measure analog quantities like speed and, , mathematical and logical operations. It can, , temperature., , solve addition, subtraction, division,, multiplication and other mathematical and, statistical operations., , 7 Analog computers provide less accurate results., , Digital computers provide 100% accurate results., , 8 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 9 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 10 Examples of Analog computers are: thermometer,, , Examples of digital computers are:, , analog clock, speedometer etc., , Personal Computer, laptops, smart phones etc., , Special Purpose Computers, It is a computer designed to solve specific type of, problem. The computers used in ships and aircrafts, etc., General Purpose computers, It is a computer designed to solve a wide variety of, problems, A General purpose Computer can store, different programs and process them., The differences between analog and digital computers, are listed in table 2, Hybrid Computer (Fig. 4), A hybrid computer is a combination of both analog and, digital computer. Hybrid computer can handle both, analog and digital data. A hybrid computer combines the, best characteristics of both the analog and digital, computer. It can accept data in both analog and digital, form., Applications, Hybrid computer devices are used in hospitals that may, calculate patient's heart function, temperature and blood, pressure etc. This calculation may be converted into, , numbers and shown in digital form. For example, The Vital, Signs Monitoring unit also called (VSM) in short. It has, Blood Pressure monitor, ECG monitor, respiratory monitor,, and is also used for monitoring anesthesia., , • Hybrid computers are also used in spaceships and, missile system., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 11
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•, , Hybrid Computer Machines are generally used in, scientific applications, , •, , Hybrid computers are used for controlling industrial, processes., , Computers are classified on the basis of computing, power, memory capacity and cost., - Microcomputer or Personal Computer., - Mini Computer., - Mainframe Computer., - Super Computer., Micro Computers, Micro computer is also called personal computer. It was, introduced in 1970. Examples of personal computers are, PC and Apple Macintosh. The major types of personal, computers are desktop computer and portable computer., Desktop Computer, , Fig 6, , CP110116B, , These computers can easily fit on a table or desktop,, hence the name. These computers come in two models, or casings. In Desktop model, the system unit is placed, on the desktop or table. Monitor is placed on the system, unit. In Tower model, both monitor and system unit are, placed on the table as in (Fig 5)., , Palmtops have no keyboard but the screen serves both, as an input and output device. It easily fits in the hand of, the user., Uses of Micro Computer, The PC is the most common type of computer used in, the office. It is now widely used in many homes. These, are also used for business and engineering application., , Portable computer, Portable is a personal computer that can be carried from, one place to other easily. Notebook computer and, handheld computer (smart phone) are examples of, portable computers. Notebook computer is also called, laptop computer. Laptop computers are very small in, size and can be placed easily on lap., , Mini Computer, , Lap top computer or notebook computer, , Minicomputer can serve up to 4000 connected users, simultaneously. It is normally accessed by users via, personal computer or terminal. A device with a monitor, and keyboard is called terminal. It is also known as dumb, terminal. It has no processing power and cannot work as, stand-alone computer. Some of the minicomputers, models are VAX-8800, AS400, , The laptop computer or notebook computer will be as, shown in fig 6a and fig 6b.It is also called as tower model, computer., Palmtop Computer/Digital Diary /Notebook /PDAs:, A handheld computer (like smart phone) is also portable., Hand held computer is known as palmtop computer., 12, , Mini computers were introduced in the 1960s., Minicomputer is larger and more powerful computer than, personal computer. It can execute five million instructions, per second. It generally consists of two or more, processors., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Uses of Mini Computer, Mini computers are often used by small and medium-sized, companies to provide centralized store of information., Mainframe Computer, Mainframe computers were introduced in 1975. A, mainframe computer is a very large computer in size. It is, processors. It is designed to perform multiple tasks for, multiple users at the same time. Mainframe computers, can serve up to 50,000 users at the same time., , programs concurrently. The modern super computer, consists of thousands of microprocessors. Super computer, uses high-speed facilities such as satellite for online, processing., Sum of the super computers models are CRAY-XP, ETA10, Param and Deep Blue ., Advantages of computers, •, , A computer has a very high processing speed with high, reliability., , •, , Large volume of information can be stored in the, memory any particular data/program can be retrieved, immediately., , •, , Solution to a complicated problem is possible at a very, high speed., , •, , Processing of large volume of data saves a lot of clerical, work which reduces the processing cost., , Mainframe computers are used primarily by corporate, and governmental organizations for critical applications,, bulk data processing such as senses, industry and, consumer statistics, and transaction processing., , •, , Computers perform operations efficiently at, environments where presence of human being is not, possible such as furnace, poisonous atmosphere,, vacuum, unmanned satellite, etc., , Super computer, , Limitation of computers, , Super computers were introduced in 1980s. Super, computer is the fastest computer. Super computer is the, biggest in size and the most expensive in price than any, other computers., , •, , High initial cost., , •, , Input information has to be prepared in the form of, statements called program which requires a, considerable amount of knowledge., , •, , usage of computers will be economical only when there, is clerical data processing for large volume of data and, are repetitive in nature, , •, , It is a merely a machine it cannot correct errors on its, own., , The users access a mainframe computer through, terminal or personal computer. A typical mainframe, computer can execute 16 million instructions per second., Some of the main computers models are, •, •, , NEC 610, DEC 10, , Uses of Mainframe Computer, , It is the most sophisticated, complex and advanced, computer. It has a very large storage capacity. It can, process trillions of instructions in one second. Super, Computer is the fastest and most powerful computer of, a time. Supercomputers are very expensive., Supercomputers are used for highly calculation-intensive, tasks. Super computers are also used for specialized, applications that require immense amounts of, mathematical calculations., Applications of Super Computer, •, , Weather forecasting,, , •, , Animated graphics like in Hollywood movies,, , •, , Fluid dynamic calculations, , •, , Nuclear energy research, , •, , Space science, , •, , Weapon and missile design, , •, , Petroleum exploration, and etc., , Today, supercomputers are produced by traditional, companies such as Cray, IBM and Hewlett- Packard., Since October 2010, the Tianhe-1A supercomputer has, been the fastest in the world; it is located inChina., The main difference between a supercomputer and a, mainframe is that a supercomputer channels all its power, into executing a single program as fast as possible,, whereas a mainframe uses its power to execute many, , Functions of Computers, All computers are made up of following basic units as, shown in fig (7). They are as follows:1 Input Unit, 2 Central processing Unit (CPU), a) Arithmetic Logic Unit(ALU), b) Control Unit (CU), 3 Memory, 4 Output Unit, Input Unit, Computers need to receive data and instruction in order, to solve any problem. Therefore we need to input the, data and instructions into the computers. The input unit, consists of one or more input devices. Keyboard is the, one of the most commonly used input device. Some of, the input devices are listed in table 1., Input devices perform the following functions., •, , Accept the data and instructions from the outside world., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 13
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•, , Convert it to a form that the computer can understand., , •, , Supply the converted data to the computer system for, further processing., , Central Processing Unit (CPU) (Fig. 8), The central processing unit (CPU) is the electronic brain, , use in a computer or other digital electronic device., There are two types of memory in computer., •, •, , Primary Memory, Secondary Memory, , Output Unit, Output unit receive the informations from the processing, unit and provide the results in human readeable form., Output Devices, The some of the output devices are, • Monitor, • Printer, • Plotter, • Speaker, Applications of computers, , of the computer as in fig-8. The CPU in a personal computer, is usually a single chip. It organizes and carries out, instructions that come from either the user or from the, software. The processor is made up of many components., CPU performs the following functions:, •, •, •, , It performs all calculations., It takes all decisions., It controls all units of the computer., , Two typical components of a CPU are the following:, The arithmetic logic unit (ALU), which performs arithmetic, and logical operations., The control unit (CU), which extracts instructions from, memory and decodes and executes them, calling on the, ALU when necessary., Memory, Memory refers to the physical device used to store the, program or data on the temporary or permanent basis for, , 14, , Science: Scientists have been using computers to, develop theories and to analyse and test the data. The, high speed and accuracy of the computer allow different, scientific analyses to be carried out. They can be used, to generate detailed studies of how earthquakes affect, buildings or pollution affects weather pattern. Satellitebased applications have not been possible without the, use of computers. Moreover, it would not be possible to, get the information of the solar system and the cosmos, without computers., Education: Computers have also revolutionized the, whole process of education. Currently, the classrooms,, libraries and museums are efficiently utilizing computers, to make the education much more interesting. Unlike, recorded television shows, computer-aided education, (CAE) and computer-based training (CBT) packages are, making learning much more interactive., Medicine and Health Care: There has been an, increasing use of computers in the field of medicine., Now, doctors are using computers right from diagnosing, the illness to monitoring a patient's status during complex, surgery. By using automated imaging techniques, doctors, are able to look inside a person's body and can study, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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CP110117t1, , Fig 9, , each organ in detail (e.g. CT scans or MRI scans), which, was not possible few years ago. There are several, examples of special-purpose computers that can operate, within the human body such as cochlear implant, a, special kind of hearing aid that makes it possible for, deaf people to hear., Engineering/Architecture/Manufacturing: The, architects and engineers are extensively using computers, in designing and drawings. Computers can create objects, , that can be viewed from all the three dimensions. By using, techniques like virtual reality, architects can explore houses, that have been designed but not built. The manufacturing, factories are using computerized robotic arms to perform, hazardous jobs. Besides, computer-aided manufacturing, (CAM) can be used in designing the product, ordering the, parts and planning production. Thus, computers help in, coordinating the entire manufacturing process., , IIT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 15
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Entertainment: Computers are finding greater use in, entertainment industry. They are used to control the, images and sounds. The special effects, which, mesmerize the audience, would not have been possible, without the computers. In addition, computerized, animation and colourful graphics have modernized the, film industry., , Banking: Computers are extensively used in the field of, banking and finance. People can use the ATM (automated, teller machine) services 24 hours a day to deposit and, withdraw cash. When different branches of the bank are, connected through computer networks, the inter branch, transactions such as cheque and draft can be performed, without any delay., , Communication: E-mail or electronic mail is one of the, communication media in which computer is used. Through, e-mail, messages and reports are passed from one person, to one or more persons with the aid of computer and, telephone line. The advantage of this service is that while, transferring the messages it saves time, avoids wastage, of paper and so on. Moreover, the person who is receiving, the messages can read the messages whenever he is, free and can save it, reply it, forward it or delete it from the, computer., , Railway Reservation System, , Business Application: This is one of the important uses, of the computer. Initially, computers were used for batchprocessing jobs, where one does not require the, immediate response from the computer. Currently,, computers are mainly used for real-time applications (like, at the sales counter) that require immediate response, from the computer. There are various concerns where, computers are used such as in business forecasting, to, prepare pay bills and personal records, in banking, operations and data storage, in various types of life, insurance business and as an aid to management., Businesses are also using the networking of computers,, where a number of computers are connected together, to share the data and the information. Use of e-mail and, the Internet has changed the ways of doing business., Publishing: Computers have created a field known as, desktop publishing (DTP). In DTP, with the help of, computer and a laser printer one can perform the, publishing job all by oneself. Many of the tasks requiring, long manual hours such as making table of contents and, index can be automatically performed using the, computers and DTP software., , 16, , Using this system, the user can perform following, operations through online. (web site: www.irctc.co.in), •, •, •, •, , search the train and its timings, check seats and birth availability, booking and cancelling tickets, status of PNR (Passenger Name Record), , Telephone / Electricity Board Billing:, The users can do the following operations through online, by using this system. (Web site: portal.bsnl.in - BSNL), • Register the telephone / electricity board number, • Check and pay the bill amount, • Register the complaints, E-Governance, E-Governance implies technology driven governance., E-Governance is the application of Information and, Communication Technology (ICT) for delivering, government services, exchange of information, communication transactions, integration of various standalone systems and services between Government-toCitizens, (G2C),, Government-toBusiness(G2B),Government-to-Government( G2G) as, well as back office processes and interactions within the, entire government frame work., E-Governance covers all the sectors with a view to, providing hassle free, transparent and efficient service, to the common man (both in urban and rural areas)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise1.2.06, COPA - Introduction to computer components, Introduction to CPU architecture and motherboard, Objectives: At the end of this lesson you shall be able to, • state what is hardware and test the internal and external hardware, • brief the listed hardware, • state what is partitions and their types, • explain the booting and its procedures., Computer Hardware, The physical units of a computer are called as the, hardware of a computer., Internal hardware examples, •, , Blu-Ray, CD-ROM, and DVD, , •, , CPU, , •, , Hard drive, , •, , Motherboard, , •, , RAM, , •, , Sound card, , •, , Video card, , •, , SMPS, , External hardware examples, •, , Flat-panel, Monitor, and LCD, , •, , Keyboard, , •, , Mouse, , •, , Printer, , •, , Scanner, , CPU & ALU, Central Processing Unit (CPU) is the heart of the, Computer. It is the hardware,that carries out the, instructions of a computer program by performing the, basic arithmetical, logical, and input/output operations, of the system., , Most connectors are separated, permitting the cable to, be plugged in only in the correct direction. The keyboard, and mouse use "PS2" (Personal System 2) connectors., The PS2 connectors are color-coded. The purple, connector is for the keyboard. The green connector is, for the mouse., •, , PS/2 Ports: Standard keyboards and mouse often, connect to the computer via the PS/2 ports. To plug, in a keyboard or mouse cable, first match the cable, to the connector. Then push the cable into the, connector. Be sure not to force the connector because, you will end up bending the pins, , •, , Serial & Parallel Ports: The serial port and parallel, port allow connections to printers and other external, devices. To transfer a byte through a serial port, eight, bits are queued and sent bit by bit. However, in a, parallel port, all the eight bits are transferred, simultaneously, , •, , The parallel port, serial port, and video port all use "D", type connectors (DB-25M, DB-9M and DB-15F, respectively). These are called D connectors because, of their shape, which permits the cables to be plugged, in only one way., , CPU Ports and Connectors, A port is a connector at the back of a Computer cabinet, where you plug in an external device such as a printer,, keyboard, scanner, modem etc. This allows instructions, and data to flow between the computer and the device., The computer ports are also commonly referred to as, the Input/output ports (I/O ports). These ports can be, either serial or parallel. Fig 1 shows the commonly, available ports on a personal computer., , Copyright @ NIMI Not to be Republished, , 17
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USB (Universal serial bus) Ports, , The System Unit and Its Components, , Devices like digital cameras, scanners and printers often, connect to the motherboard via the USB ports. A USB, connector's distinctive rectangular shape makes it easily, recognizable., , The system unit is a box-like unit filled with a number of, useful components, each performing a discrete function., These components work together to accomplish the main, function of the computer, viz. accept and process input, and deliver output. This section will elaborate on these, components one by one. Fig 3 shows the various, components of the system unit., , USB has a number of features that makes it particularly, popular on PCs. First, USB devices are hot swappable., You can insert or remove them without restarting your, system, LAN(Local Area Network) Port: The LAN port is used, to connect the PC to a local network or to high speed, Internet services., , Fig 3, , VGA (Video Graphics Array) Ports: The VGA port, provides access to integrated video., Audio ports: It provides access to integrated audio., The audio jacks are the most confusing connectors on, the back panel. Although the jacks are sometimes colorcoded, the devices that plug into them rarely., CPU front Panel shown Fig 2., , CP11011B, , Fig 2, , Power Supply, The power supply connects to nearly every device in the, PC to provide power. It is located at the rear of the case., The system unit draws power from the AC mains through, a power protection device., , It may contain the following parts., , • Power On/Off Switch, • Power Indicator, • CD/DVD Drive, • CD/DVD Drive Open/Close Button, • CD/DVD Drive indicator, • Floppy Disk Drive, • Floppy Disk Drive Indicator, • USB Ports, • Audio and Mic connectors, Design of CPU Cabinets may vary based on, the manufacturer., , 18, , This power is not directly supplied to the internal, components. Instead, one of the components, called the, internal power supply, converts the AC input into DC, output of 5 and 12 volts. Normally, the internal power, supply is referred to as Switched Mode Power Supply, (SMPS)., The SMPS provides cable connectors to supply the, required voltage to the other internal components like, the floppy drives, the hard disk drive, the motherboard, and external device such as the keyboard. The ON/OFF, switch of the system unit is actually a part of the SMPS., Fan, The SMPS has a small fan, called the exhaust fan,, attached to SMPS(Fig. 4). This fan rotates as long as, the computer is switched on. Its function is to cool the, SMPS unit., Drive Bays: The 5.25" and 3.5" drive bays house the, many kinds of storage devices a computer might contain., Expansion Slots: An expansion slot is a slot located, inside a computer mother board that allow additional, peripharals to be connected to it., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Power Port: Power is delivered to drives via cables that, plug into the power port on the drives., , Fig 4, , Peripheral cards slot, The peripheral cards are the spare expansion slots, available on the mother board on which peripheral cards, can be inserted., , CP11011C, , The following are the peripheral cards, , Memory Slot, , •, , Sound card, , •, , Video card, , •, , Modam, , •, , Wireless network, , Fig. 7 shows the peripheral card, designed with a PCI, (Peripheral component interconnect) connector., Fig 7, , Memory Slot is used to insert a Random Access, Memory(RAM) shown in fig 5, , Storage Drivers, Storage drivers such as hard drives, optical drives and, floppy drives all connect to the motherboard via cables, and is mounted inside the computer., IDE & SATA Cables: Fig 6 shows two hard disk drives, that connect in different ways to the motherboard. One, uses the older IDE cable connection while the other uses, SATA(Serial Advanced Technology Attachment) cable, which provides for faster hard drive access., , CP11011F, , CP11011D, , Fig 5, , Motherboard, The motherboard is a printed circuit that is the foundation, of a computer and allows the CPU, RAM, and all other, computer hardware components to function with each, other as on fig 8., Fig 8, , CP11011G, , Fig 6, , CP11011E, , "www. dget.gov.in", , The motherboard is the primary component of the entire, system. A mother board is a large board containing a, number of tiny electronic circuits and other components, are visible. All peripheral devices are connected to the, motherboard. The components of the motherboard are:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 19
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This means you can upgrade to a newer version of DOS, without changing the BIOS. PC BIOS that can handle, Plug-and-Play (PnP)devices are known as PnPBIOS,, These BIOS are always implemented with flash memory, rather than ROM., , •, , Keyboard / mouse port, , •, , Parallel and Serial port, , •, , Processor Socket, , •, , AGP Slot, , CMOS Battery, , •, , PCI Slots, , •, , ISA Slot, , •, , CMOS Battery, , CMOS (Complementary Metal-Oxide-Semiconductor) is, the term usually used to describe the small amount of, memory on a computer motherboard that stores the BIOS, settings., , •, , Data Card Connector, , •, , Memory Slots, , •, , Floppy Port, , •, , Fan Header, , •, , Main Power Connector, , Most CMOS batteries will last the lifetime of a, motherboard (up to 10 years in most cases) but will, sometimes need to be replaced. Incorrect or slow system, date and time and loss of BIOS settings are major signs, of a dead or dying CMOS battery., ISA slot: (Industry Standard Architecture) It is the, standard architecture of the Expansion bus. Motherboard, may contain some slots to connect ISA compatible cards., , Floppy Port :The floppy drive connects to the computer, via a 34-pin ribbon cable, which in turn connects to the, motherboard. A floppy controller is one that is used to, control the floppy drive., RAM slots: Random-Access Memory (RAM) stores, programs and data currently being used by the CPU., RAM is measured in units called bytes. RAM has been, packaged in many different ways, •, , SIMM-Single inline memory module -32 or 72 Pin, , •, , DIMM- Dual Inline Memory module -168 pin., , In most of the PC's uses of the DIMM module, ROM BIOS Chip: This means Read Only Memory Basic, Input-Output System., The built-in software that determines what a computer, can do without accessing programs from a disk. On PCs,, the BIOS contains all the code required to control the, keyboard,, display, screen,, disk, drives,, serialcommunications, and a number of miscellaneous, functions., The BIOS is typically placed in a ROM chip that comes, with the computer (it is often called a ROM BIOS). This, ensures that the BIOS will always be available and will, not be damaged by disk failures., It also makes it possible for a computer to boot itself., Because RAM is faster than ROM, though, many, computer manufacturers design systems so that the, BIOS is copied from ROM to RAM each time the, computer is booted. This is known asshadowing., Many modern PCs have flash BIOS, which means that, the BIOS have been recorded on a flash memory chip,, which can be updated if necessary. The PC BIOS is fairly, standardized, so all PCs are similar at this level (although, there are different BIOS versions). Additional DOS, functions are usually added through software modules., 20, , PCI slot : Intel introduced the Peripheral Component, Interconnect bus protocol. The PCI bus is used to, connect I/O devices to the main logic of the computer., PCI bus has replaced the ISA bus. PC motherboards, have one PCI slot but generally more than one., The PCI bus architecture is a processor-independent bus, specification that allows peripherals to access system, memory directly without using the CPU., AGP slot: The Accelerates Graphics Port (AGP) is a, high-speed point-to-point channel for attaching a video, card to a computer's motherboard., Power supply plug in, The Power supply, as its name implies, provides the, necessary electrical power to make the PC (Personal, Computer) operate. The power supply takes standard, 110-V AC power and converts into +/-12-Volt, +/-5-Volt,, and 3.3-Volt DC power. The power supply connector has, 20-pins, and the connector can go in only one direction., Hard Disk and Partitions, Partitioning is a process of dividing the Hard disk into, several chunks, and uses any one of the portion or, partition to install OS or use two or more partitions to, install multiple OS.., But it can always have one partition, and use up the, entire Hard disk space to install a single OS, but this will, become data management nightmare for users of large, Hard disks., Now, because of the structure of the Master Boot Record, (MBR), has only four partitions, and these four partitions, are called Primary Partitions., Extended Partition is not a usable partition by itself,, but it's like a "container" and it is used to hold, LogicalDrives!That is this Extended Partition can be, subdivided into multiple logical partitions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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In order to boot into a Partition, it must be designated, as bootable partition or Active Partition. Active Partition, is that partition which is flagged as bootable or which, contains OS, this is generally a Primary Partition., , Fig 9, , Types of Partitions:, •, , Master, , •, , Partition, , •, , Extended and, , •, , Logical Extended, , Master Boot Record (MBR): MBR is a small 512 bytes, partition which is at the first physical sector of the hard, disk. The location is denoted as CHS 0,0,1 meaning 0th, Cylinder, 0th Head and 1st Sector., MBR contains a small program known as bootstrap, program which is responsible for booting into any OS., MBR also contains a table known as Partition Table., This Partition Table is a table which lists the available, Primary Partitions in the hard disk. Partition table, considers whole Extended Partition as one Primary, partition and lists it in the table!, So a Partition table can have two possible entries:•, , Up to 4 Primary Partitions., , •, , Up to 3 Primary Partitions and 1 Extended, Partition.(Total not exceeding 4) ., , Partition Boot Sector (PBR): This is the logical first, sector, that is sector at the start of a Primary Partition., This is also 512 byte area, which contains some programs, to initialize or run OS files. All Primary Partitions have, its own PBRs., Extended Boot Sector (EBR): This is the logical first, sector, that is the sector at the start of the Extended, Partition. This EBR contains a Partition Table, which lists, the available Logical Partitions inside Extended Partition., That is it contains the Starting addresses of each Logical, Partitions., Logical Extended Boot Sector (LEBR): This is the, logical first sector residing at the start of each Logical, Partition. This is similar to PBR for Primary Partitions., Booting, Booting is a process of loading the operating system, (OS) and checking all the system software and hardware, those are installed in the computer., Booting procedure of Windows operating system, Functions of BIOS, The first process starts, when the computer switched on, Basic Input Output System (BIOS) perform two functions,, to conduct POST and read MBR (Fig 9)., , POST - POST stands for Power OnSelf Test. POST, checks all the hardware devices connected to a computer, like RAM, hard disk etc and make sure that the system, can run smoothly with those hardware devices. If the, POST is a failure the system halts with a beep sound., Now BIOS checks the boot priority. We can set the, boot priority as CD drive, hard disk or floppy drive., MBR - The next duty of BIOS is to read the MBR. MBR, stands for Master Boot Record and it's the first sector on, a hard disk. MBR contains the partition table and boot, loader., Functions of Boot loader, Now BIOS has passed the control to boot loader and, boot loader is a small program which loads kernel to, computers memory. Actually there are two stages of boot, loaders, stage 1 boot loader and stage 2 boot loader., The stage 1 boot loaderis a link to the stage 2 boot loader., The stage 2 boot loader resides in the boot partition and, it loads the kernel to memory., Boot files and functions, There are three boot files in a Windows operating system, and they are NTLDR, NTDETECT.COM and Boot.ini., The boot files are found in the active partition of hard, disk and its normally C drive in a Windows machine., NTLDR - NTLDR stands for NT Loader and it's the, second stage boot loader. The path of NTLDR is, C:\Windows\i386\NTLDR., Boot.ini - Boot.ini contains the configuration files of, NTLDR. When the operating system is loaded we cannot, pass any arguments to kernel, so those arguments are, passed through boot.ini. You can edit boot.ini by opening, through notepad. The path of Boot.ini is C:\boot.ini., NTDETECT.COM, This file detects hardware's and passes information to, NTLDR. Using the collected information the NTLDR, creates a hardware key and this key is used to detect, hardware's., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 21
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A new hardware key is generated after each reboot of the, operating system and that's why system asks to reboot, after installation of a new hardware. The hardware keys, created by NTLDR can be found in Windows registry at, HKEY_LOCAL_MACHINE ' HARDWARES., Kernel and its functions, After executing the functions of boot files the control is, passed to Kernel. ntoskrnal.exe is the kernel file in a, Windows machine and its path is C:\Windows\system, 32\ntoskrnal.exe., Kernel acts as a layer between software and hardware., The library file hal.dll (C;\Windows\system32\hal.dll) helps, Kernel to interact with hardware's. HAL stands for Hardware, Abstraction Layer and this hal.dll file is machine specific., Now the drivers for hardware's are loaded from the file, C:\Windows\system32\config\system and the Kernel is, loaded to primary memory., Services and log in procedure, When kernel is loaded in the primary memory, services, for each process is started and the registry entry for those, services can be found at HKEY_LOCAL_MACHINE System - Current control set - Services., Winlogon.exe (C:\Windows\system32\winlogon.exe) is, the last service started during this process., Winlogon.exe starts the log in procedures of windows, machine. It first calls the library file msgina.dll, (C:\Windows\system32\msgina.dll)., MSGINA stands for Microsoft Graphics Identification and, Authentication and it provides the log in window. Now, msginal.dll passes the control to LSA (Local Security, Authority), it verifies the username and password from, the SAM file. SAM (Security Accounts Manager) contains, the information about all users created in a Windows, operating system., Now the booting procedure is over and it has reached, the desktop of Windows operating system., Voltage: Every electric charge is capable of doing work, by moving another charge either by attraction or by, repulsion. This ability of a charge to do work represents, its potential. Voltage is generated by the separation of, charges. Voltage or electric potential is the state of, separated charges striving to neutralize each other. The, unit of electric potential is volt. Potential difference is, necessary to cause flow of electric current., Methods of voltage generation: Voltage can be generated, by several ways. Some methods of generating coltage, are:, , • Voltage from chemical reactions, Measuring voltage: Voltage exists between any two, points with different levels of charge. Voltage between, any two points can be measured using an instrument, called VOLTMETER. Meters used to measure current is, called Ammeter. There are meters which can be used to, measure voltage and current and a few other electrical, parameters like resistance. Such meters are called, MULTIMETERS., Types of voltage: As discussed in above paragraphs there, are several sources by which voltage can be developed., Depending upon the voltage source, the voltage developed, can be,, Direct voltage: It is of constant magnitude. It remains at, the same amplitude from the moment it is switched ON, till the moment it is switched - OFF., Alternating voltage: In this type, voltage source changes, its polarity regularly and therefore the direction of, developed voltage., A mixed voltage is a combination of direct voltage and, alternating voltage. The level of voltage is not constant., It varies around a mean value., Electric Current: Electric current is produced when, electric charges move in a definite direction. This, movement is not only of negative charges but also of, positive charges. The strength of electric current is the, quantity of charge which flows across a given cross, section of a conductor every second. The unit of current, strength is Ampere., Current strength = Quantity of charge/time, Measuring current: Electric current is the flow of charge,, in a conductor. So, to measure current must pass through, the measuring device. The current measuring instrument, is called the ammeter of the current meter. There are, different types of ammeters used for measuring different, quantities of current., Types of current: Voltage causes electrical current to, flow. If the cause of current flow is a direct voltage source,, then the current caused by its called direct current (d.c)., On the otherhand, then the current caused is referred as, the alternating current. If a mixed voltage AC and DC) is, applied to an electrical circuit, a mixed current (AC and, DC) will flow through the circuit., Types of power supply: Irrespective of how the, electricity is generated, electricity can be classified into, two types., •, , Alternating current, generally known as AC supply., Direct current, generally known as DC supply., , •, , Voltage from friction, , •, , •, , Voltage from moving magnets or coils, , •, , Voltage from pressure or tension in crystals, , •, , Voltage from heat, , AC supply: The term alternating current supply is given to, a supply source that makes current to flow through a circuit, which reverses or alternates its direction periodically., , •, , Voltage from light, , 22, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Advantages of AC supply, •, , Reduced transmission loss over long distances., , •, , Voltage levels can be changed using simple devices, called transformers., , •, , Reduced severity of electrical shock., , •, , Generating equipments are simple and cheaper, , •, , Can be easily converted to DC supply., , DC supply: The term direct current supply is given to a, supply source that makes current to flow through a circuit, in one direction only. Example of DC supply is batteries., Some types of generators are also designed to give d.c., supply. Such generators are called DC generators., Low tension (LT) voltage: The domestic voltage of 240, volts AC (generated and supplied by hydro or Thermal, or Nuclear generating stations) is called the low tension, (LT) voltage. LT lines enters residential buildings from, electricity poles called as service connection. This 240, volts is used to light up the lamps, run fans etc in homes., To connect electrical appliances at home, 240V AC is, available in either two-pin or three - pin sockets. This LT, voltage of 240 volts, 50Hz is also used to supply electrical, and electronic gadgets such as Iron box, washing, machine, personal computer etc., Phase, Neutral and Earth points of LT supply: The, domestic AC mains supply of 240V, 50Hz, is available, at consumers residence either in a 2-pin outlet (Phase Neutral) or in a 3-pin outlet (phase -Neutral and Ground)., These are commercially referred to as 2/3 pin sockets., These sockets look similar to the ones shown in Fig. 10., , recorders etc., Hence such gadgets does not need earth, pin/point on the socket., Iron box, washing machines, drill guns, Desk top computer, invariably need sockets with provision of earth pin, because, of the possibility of shock while using these equipments., Hence such equipments/gadgets make use of AC mains, socket with earth., Connection of 3-pin AC mains socket: Fig 11 shows, how the main supply is connected to the socket., Fig11, , Note that in a AC outlet be it a 2-pin or a 3-pin phase is, always connected to the socket through a switch. This, prevents the users from getting electrical shock when the, switch is put in off position., The standard voltage appearing across the 3-pin terminals, is shown in Fig12, Fig 12, , Fig 10, , Phase: The line or phase point in a socket, can be termed, as the point from where the electricity starts flowing into a, closed circuit., Neutral: The neutral point in the socket, can be termed, as the point which receives electricity from the closed, circuit., Earth / Ground: The ground (some call it Earth) point in, an electrical socket provides the easiest path for the, leakage current and other minor electrical defect currents, of appliances., Two pin mains sockets are used to supply main to such, equipments or apparatus or gadgets generally having its, cabinets/chassis made of plastic such as radio, tape, , The voltages across the pins of the socket can be measured, using an AC voltmeter or a multimeter in AC volts range., As a quick test to find out whether or not a socket is, delivering the AC supply as required, a simple instrument, called line tester which looks similar to a small screw, driver can be used. This instrument will have a small, bulb in it which glows if it is touched to the phase pin in, the socket. Ask your instructor to demonstrate the use of, such line tester to check a AC mains socket., Most Desk top computers need AC mains supply for its, operation. Although the mains supply available in the 3pin socket shown above can be used, mostly this AC, supply is cleaned fro spikes before connecting to, computers. The device used for cleaning the spikes in the, mains AC supply are called Spike Arrestors or Spike, busters., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 23
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Computers are used with spike busters because, AC spikes, are likely to damage the costly computers. In addition to, spike busters, most computers use other power safety, devices called the voltage stabilizers and uninterrupted, power supplies., , 24, , Power supply in computers: Power supply unit in, computers are firmly fitted on the processing unit cabinet, using torx screws. Generally there will be four such screws, fitted to fix the power supply init in the cabinet., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise : 1.3.07 - 1.3.11, COPA - Windows Operating System, Windows Operating System, Objective: At the end of this exercise you shall be able to, • list out the windows versions and features, Windows versions and its features, Microsoft Windows has seen nine major versions since, its first release in 1985. Over 29 years later, Windows, looks very different but somehow familiar with elements, that have survived the test of time, increases in, computing power and - most recently - a shift from the, keyboard and mouse to the touchscreen., Here's a brief look at the history of Windows, from its, birth at the hands of Bill Gates with Windows 1 to the, latest arrival under new Microsoft chief executive, SatyaNadella., , Apple's Macintosh and the Commodore Amiga graphical, user interfaces, coming pre-installed on computers from, PC-compatible manufacturers including Zenith Data, Systems., Windows 3 introduced the ability to run MS-DOS, programmes in windows, which brought multitasking to, legacy programmes, and supported 256 colours bringing, a more modern, colourful look to the interface., More important - at least to the sum total of human time, wasted - it introduced the card-moving timesink (and, mouse use trainer) Solitaire., , Windows 1, , Windows 3.1, , The first version of Windows, , Windows 3.1 with Minesweeper., , This is where it all started for Windows. The original, Windows 1 was released in November 1985 and was, Microsoft's first true attempt at a graphical user interface, in 16-bit., , Windows 1 and 2 both had point release updates, but, Windows 3.1 released in 1992 is notable because it, introduced TrueType fonts making Windows a viable, publishing platform for the first time., , Development was spearheaded by Microsoft founder Bill, Gates and ran on top of MS-DOS, which relied on, command-line input., , Minesweeper also made its first appearance. Windows, 3.1 required 1MB of RAM to run and allowed supported, MS-DOS programs to be controlled with a mouse for, the first time. Windows 3.1 was also the first Windows, to be distributed on a CD-ROM, although once installed, on a hard drive it only took up 10 to 15MB (a CD can, typically store up to 700MB)., , It was notable because it relied heavily on use of a mouse, before the mouse was a common computer input device., To help users become familiar with this odd input system,, Microsoft included a game, Reversi (visible in the, screenshot) that relied on mouse control, not the, keyboard, to get people used to moving the mouse, around and clicking onscreen elements., Windows 2, Windows 2 with overlapping windows., Two years after the release of Windows 1, Microsoft's, Windows 2 replaced it in December 1987. The big, innovation for Windows 2 was that windows could overlap, each other, and it also introduced the ability to minimise, or maximise windows instead of "iconising" or "zooming"., The control panel, where various system settings and, configuration options were collected together in one, place, was introduced in Windows 2 and survives to this, day., Microsoft Word and Excel also made their first, appearances running on Windows 2., Windows 3, Windows 3.0 got colourful., The first Windows that required a hard drive launched in, 1990. Windows 3 was the first version to see more, widespread success and be considered a challenger to, , Windows 95, Windows 95: oh hello Start menu., As the name implies, Windows 95 arrived in August 1995, and with it brought the first ever Start button and Start., It also introduced the concept of "plug and play" - connect, a peripheral and the operating system finds the, appropriate drivers for it and makes it work. That was, the idea; it didn't always work in practice., Windows 95 also introduced a 32-bit environment, the, task bar and focused on multitasking. MS-DOS still, played an important role for Windows 95, which required, it to run some programmes and elements., Internet Explorer also made its debut on Windows 95, but, was not installed by default requiring the Windows 95 Plus!, pack. Later revisions of Windows 95 included IE by default,, as Netscape Navigator and NCSA Mosaic were popular at, the time., Windows 98, Windows 98, the last great DOS-based Windows., Released in June 1998, Windows 98 built on Windows, 95 and brought with it IE 4, Outlook Express, Windows, , Copyright @ NIMI Not to be Republished, , 25
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Address Book, Microsoft Chat and NetShow Player, which, was replaced by Windows Media Player 6.2 in Windows, 98 Second Edition in 1999., , CD burning, autoplay from CDs and other media, plus, various automated update and recovery tools, that unlike, Windows ME actually worked., , Windows 98 introduced the back and forward navigation, buttons and the address bar in Windows Explorer, among, other things. One of the biggest changes was the, introduction of the Windows Driver Model for computer, components and accessories - one driver to support all, future versions of Windows., , Windows XP was the longest running Microsoft operating, system, seeing three major updates and support up until, April 2014 - 13 years from its original release date., Windows XP was still used on an estimated 430m PCs, when it was discontinued., , USB support was much improved in Windows 98 and, led to its widespread adoption, including USB hubs and, USB mice., Windows ME, Windows ME was one to skip., Considered a low point in the Windows series by many at least, until they saw Windows Vista - Windows, Millennium Edition was the last Windows to be based on, MS-DOS, and the last in the Windows 9x line., Released in September 2000, it was the consumer-aimed, operating system twined with Windows 2000 aimed at, the enterprise market. It introduced some important, concepts to consumers, including more automated, system recovery tools., IE 5.5, Windows Media Player 7 and Windows Movie, Maker all made their appearance for the first time., Autocomplete also appeared in Windows Explorer, but, the operating system was notorious for being buggy,, failing to install properly and being generally poor., Windows 2000, Windows 2000 was ME's enterprise twin., The enterprise twin of ME, Windows 2000 was released, in February 2000 and was based on Microsoft's businessorientated system Windows NT and later became the, basis for Windows XP., Microsoft's automatic updating played an important role, in Windows 2000 and became the first Windows to, support hibernation., Windows XP, Windows XP still survives to this day., Arguably one of the best Windows versions, Windows, XP was released in October 2001 and brought Microsoft's, enterprise line and consumer line of operating systems, under one roof., Advertisement, It was based on Windows NT like Windows 2000, but, brought the consumer-friendly elements from Windows, ME. The Start menu and task bar got a visual overhaul,, bringing the familiar green Start button, blue task bar, and vista wallpaper, along with various shadow and other, visual effects., ClearType, which was designed to make text easier to, read on LCD screens, was introduced, as were built-in, 26, , Its biggest problem was security: though it had a firewall, built in, it was turned off by default. Windows XP's huge, popularity turned out to be a boon for hackers and, criminals, who exploited its flaws, especially in Internet, Explorer, mercilessly - leading Bill Gates to initiate a, "Trustworthy Computing" initiative and the subsequent, issuance of to Service Pack updates that hardened XP, against attack substantially., Windows Vista, Windows Vista, arguably worse than Windows ME., Windows XP stayed the course for close to six years, before being replaced by Windows Vista in January 2007., Vista updated the look and feel of Windows with more, focus on transparent elements, search and security. Its, development, under the codename "Longhorn", was, troubled, with ambitious elements abandoned in order, to get it into production., Advertisement, It was buggy, burdened the user with hundreds of requests, for app permissions under "User Account Control" - the, outcome of the Trustworthy Computing initiative which, now meant that users had to approve or disapprove, attempts by programs to make various changes., The problem with UAC was that it led to complacency,, with people clicking "yes" to almost anything - taking, security back to the pre-UAC state. It also ran slowly on, older computers despite them being deemed as "Vista, Ready" - a labelling that saw it sued because not all, versions of Vista could run on PCs with that label., PC gamers saw a boost from Vista's inclusion of, Microsoft's DirectX 10 technology., Windows Media Player 11 and IE 7 debuted, along with, Windows Defender an anti-spyware programme. Vista, also included speech recognition, Windows DVD Maker, and Photo Gallery, as well as being the first Windows to, be distributed on DVD. Later a version of Windows Vista, without Windows Media Player was created in response, to anti-trust investigations., Windows 7, Windows 7 was everything Windows Vista should, have been., Considered by many as what Windows Vista should have, been, Windows 7 was first released in October 2009. It, was intended to fix all the problems and criticism faced, by Vista, with slight tweaks to its appearance and a, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished
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concentration on user-friendly features and less "dialogue, box overload"., It was faster, more stable and easier to use, becoming, the operating system most users and business would, upgrade to from Windows XP, forgoing Vista entirely., Handwriting recognition debuted in 7, as did the ability, to "snap" windows to the tops or sides of the screen,, allowing faster more automatic window resizing., , Windows 8.1, Windows 8.1 and the great reappearance of the Start, button., A free point release to Windows 8 introduced in October, 2013, Windows 8.1 marked a shift towards yearly, software updates from Microsoft and included the first, step in Microsoft's U-turn around its new visual interface., , Windows 7 saw Microsoft hit in Europe with antitrust, investigations over the pre-installing of IE, which led to, a browser ballot screen being shown to new users, allowing them to choose, which browser to install on first, boot., , Windows 8.1 re-introduced the Start button, which, brought up the Start screen from the desktop view of, Windows 8.1. Users could also choose to boot directly, into the desktop of Windows 8.1, which was more suitable, for those using a desktop computer with a mouse and, keyboard than the touch-focused Start screen., , Windows 8, , Windows 10, , Windows 8 focused more on touch than a keyboard, and mouse., , With Windows 10, Microsoft is trying to keep some of, the touch and tablet features it created for Windows 8,, combine them with the familiar Start menu and desktop,, and run it all on top of an improved operating system, with more security, a new browser, the Cortana assistant,, its own version of Office for on-the-go editing and plenty, of new features intended to make life simpler., , Released in October 2012, Windows 8 was Microsoft's, most radical overhaul of the Windows interface, ditching, the Start button and Start menu in favour of a more touchfriendly Start screen., Advertisement, The new tiled interface saw programme icons and live, tiles, which displayed at-a-glance information normally, associated with "widgets", replace the lists of, programmes and icons. A desktop was still included,, which resembled Windows 7., , Of course, that also means it's very different to use,, whether you come from Windows 7, Windows 8 or, Windows XP. You have to look in a new place even to, turn your PC off., , Windows 8 was faster than previous versions of Windows, and included support for the new, much faster USB 3.0, devices., , On top of that, Windows 10 is more than just a PC, operating system; it's also what will run on Windows, phones - and on small tablets as well, because a 6-inch, phone and a 7-inch tablet aren't such very different, devices., , The Windows Store, which offers universal Windows, apps that run in a full-screen mode only, was introduced., Programs could still be installed from third-parties like, other iterations of Windows, but they could only access, the traditional desktop interface of Windows., , Microsoft is expecting people to put Windows 10 on a, billion devices (which ought to encourage more app, developers to at least take a look at building their apps, for Windows phones and tablets, as well as for Xbox, One and HoloLens)., , The radical overhaul was not welcomed by many., Microsoft attempted to tread a fine line between, touchscreen support and desktop users, but ultimately, desktop users wanting to control Windows with a, traditional mouse and keyboard and not a touchscreen, felt Windows 8 was a step back., , The Start menu evolves, , There were also too few touchscreens in use, or on offer,, to make its touch-oriented interface useful or even, necessary - despite the parallel rise of tablets such as, the iPad, and smartphones, which had begun outselling, PCs by the end of 2010., , The full-screen Start screen of Windows 8 is back to, being a Start menu in Windows 10 that tries to combine, the best of both options. A scrolling Start menu that's, restricted to a single column, with jump lists and flyout, menus for extra options, divided into frequently used, and recently installed programs, with the option to switch, to a scrolling view of all the applications, sorted, alphabetically., Fig 1, , It looked and felt like Windows 8, but could not run, traditional Windows applications, instead solely relying, on the Windows Store for third-party apps., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13701, , Windows RT, which runs on ARM-based processors, traditionally found in smartphones and non-PC tablets,, was introduced at the same time as Windows 8 with the, Microsoft Surface tablet., , 27
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But also get an extra pane ,where can pin Windows 8style tiles, complete with 'rotating 3D cube' animations of, live tiles. drag the Start menu to be a larger size or even, set it to be full screen., Desktop Background, Another component of the Desktop is the Background., This is simply an image that appears at the back of the, screen. Most computers come with a pre-selected, background, but change it to any image., , alternative is to use the File Explorer by clicking on the, Folder icon on the Taskbar., In the File Explorer window, browse all the folders and, documents., Fig 4, , To change the background, follow these steps:, 1. Right-click on the background and choose, "Personalize", 2. From the Personalization window, choose from a series, of pre-selected pictures or browse for your own., After choosing a picture, the Background will change, automatically., Copa 13704, , Start Menu, If looking for a specific application, open the Start Menu, and click "All Applications". This will open an alphabetical, , Fig 2, , Virtual Desktops, One of the new features of Windows 10 is the addition of, Virtual Desktops. This allows you to have multiple desktop, screens where to keep open windows organized., , Copa 13705, , Copa 13702, , Fig 5, , list of all the applications installed on computer., , To add a virtual desktop, follow these steps:, , Fig 3, , File Explorer, If you are looking for a specific document, another, , 28, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13706, , Copa 13703, , Fig 6
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1. Click Task View on the Taskbar, 2. Click the "New desktop" option on the lower-right corner., You can access or delete the new Desktop by clicking, Task View again., Cortana helps as with search and control, Cortana, the Windows Phone assistant, shows up in, , Fig 7, , If Cortana isn't active, can turn it on by typing "Cortana" in, the Taskbar search to access the Cortana settings, or, just clicking the "Gear" icon on the left-side of the menu., After activating Cortana, it will start gathering information, about to personalize the experience., Task switcher, Most Windows users don't know the Alt-Tab keyboard, , Copa 13707, , Fig 10, , Windows 10 as a search pane on the taskbar, which can, also trigger by saying 'Hey Cortana' - and when start, searching the Start menu., Fig 8, , combination to see and switch between all running apps,, so as well as having a redesigned task switcher with bigger, , Copa 13708, , Fig 11, , That gets theapps have installed, documents access to,, apps could install from the Store, search results from the, web and a range of other information - including from apps, and services that integrate with Cortana., Activating Cortana, , Copa 137011, , Fig 9, , thumbnails, Windows 10 also puts a task view icon in the, taskbar to help them find it., Copa 13709, , TASKBAR, The Windows 10 taskbar sits at the bottom of the screen, giving the user access to the Start Menu, as well as the, icons of frequently used applications. On the right-side,, the Taskbar features the Notification Area which informs, the user of different things like the state of the Internet, connection or the charge of the laptop battery., The icons in the middle of the Taskbar are "pinned", applications, which is a way to have a quick access to, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , 29
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applications you use frequently. "Pinned" applications, will stay in the Taskbar until you "unpin" them., , Copa 1137012, , Fig 12, , Taskbar. It shows different types of notifications from your, computer like your Internet connection, or the volume level., At first, the Notification Area shows a limited amount of, icons. But you can click the upward arrow on its left-side, to see other icons as well., Snap Assist, Because all the apps and programs run in windows on the, Fig 15, , Pin an Application to the Taskbar, Copa 137015, , Step 1: Search for the application you want to pin in the, Start Menu., Step 2: Right-click on the application., Step 3: Select "More" option at the top of the menu., Step 4: Select the "Pin to taskbar" option., Unpin an Application from the Taskbar, To "unpin" it, just right-click the icon in the Taskbar and, select "Unpin from taskbar". You can "pin" it back again, , desktop, instead of modern apps from the Store being in, their own space, and can no longer drag across the left, edge of the screen to bring another app on screen and get, a split view. Instead, drag windows into the corners of the, screen to get the familiar Snap view., Now use all four corners of the screen if want each window, to take up a quarter of the screen instead of half, and the, space that isn't filled by the window you just dragged shows, thumbnails of your other windows to make it easier to, snap the next one into place., , Fig 13, , Action Center, , Copa 137013, , If we used Windows Phone 8.1 (or Android and/or iOS),, we used to a notification centre can drag down from the, top of the screen., , any time you want., Notification Area, The Notification Area is located at the right side of the, , Fig 14, , The command prompt, Those of us that use the command prompt have been, stuck with pretty much the same experience since the, 1990s, but in Windows 10 can finally resize the, command prompt window and use familiar keyboard, shortcuts to copy and paste at the command prompt., It's far from ground-breaking but it's a very welcome, improvement after years of frustration., FILE EXPLORER, , Copa 137014, , 30, , Windows 10 puts that on the right of the screen, where, the charms bar was in Windows 8, with notifications from, various apps at the top and the choice of various settings, buttons at the bottom for quick access., , File Explorer is the file management application used, by Windows operating systems to browse folders and, files. It provides a graphical interface for the user to, navigate and access the files stored in the computer., The main way to access the File Explorer is by clicking, the folder icon in the Taskbar. After clicking the icon, the, File Explorer window will open., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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Multiple desktops, , Fig 15, , User need to arrange a lot of windows and don't have, multiple monitors, user can put them on multiple virtual, desktops. And can use Alt-Tab to move between apps, as usual and then Windows-Ctrl and the left and right, arrow keys to move between desktops., , Copa 137015, , Schedule restarts, , The initial File Explorer window is comprised of the following, sections:, 1. The File Explorer ribbon, which resembles the ribbon, featured in Microsoft Office. The ribbon contains buttons, for common tasks to perform with your files and folders., 2. The Navigation Pane gives you access to your, libraries of documents and pictures, as well as your, storage devices. It also features frequently used folders, and network devices., 3. The Frequent folders section on the right features, the folders you've worked with recently to allow for quick, access to them., 4. The Recent files section in the lower part of the, window features files and documents that you've opened, recently., The new Edge browser, To catch up with fast-moving browsers like Chrome and, Firefox, Microsoft took its browser back to basics, ripping, out years of code that didn't fit with web standards and, making a lean, fast browser., It's a work in progress - it won't get support for things like, ad-blocking extensions until a while after Windows 10, launches - but can do plenty of neat things here. For, example, and can scribble notes on a web page to send, to a friend and Edge has Cortana built in to pull useful, information out of web pages, like the phone number of, a restaurant, or the opening hours., Sites like Medium that didn't work properly with IE should, look better and have more features in Edge., , No more having Windows announce that you have fifteen, minutes to get everything done before it restarts to apply, an update. Instead of leaving Windows 10 to decide when, to do that, if there's an update that will need a restart, and can have Windows ask when you want to schedule, that for., user can only do that once the update has been, downloaded. If user want to have certain times off-limits, for restarts, they will need the features in Windows, Update for Business (for Windows 10 Pro and Enterprise), which lets block restarts so they don't happen in working, hours, or on certain dates., Universal apps - including Office, Windows 10 gets a new Windows Store, where download, desktop programs as well as modern Windows apps., Many of those apps will be universal apps that are the, same code on a PC, a Windows phone, an Xbox One, and even on HoloLens, with the interface changing to, suit the different screen sizes. The Office for Windows, apps like Word and Excel are universal apps, as are the, Outlook Mail and Calendar apps., Settings and control panel, The Windows 8 Settings app has taken over many more, of the settings that used to be in Control Panel, and it, has a Control Panel-style interface with icons to navigate, with. But the old Control Panel interface is still there, for, settings that aren't in the new Settings app (or if you're, just used to finding things there)., Windows 10 - Keyboard ShortcutsUTS, Like most Windows applications, there are several, keyboard shortcuts you can use to make it easier or faster, for some to perform certain tasks., Most of the new Windows shortcuts use the Windows, key () combined with other keys to perform several, actions. The following are some of the most common or, useful shortcuts used in Windows 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished, , 31
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Keyboard Shortcuts for Navigating Windows 10, Press This, , 32, , To Do This, , Windows Logo, , Toggle the Start menu, , Windows Logo+A, , Open the Notifications pane, , Windows Logo+B, , Activate the notification area's Show Hidden Icons arrow (press Enter to display, the hidden icons), , Windows Logo+C, , Open Cortana for voice commands, , Windows Logo+D, , Minimize all open windows to display the desktop, , Windows Logo+E, , Run File Explorer, , Windows Logo+F, , Display the Start menu and activate the Search box, , Windows Logo+H, , Display the Share pane, , Windows Logo+I, , Run the Settings app, , Windows Logo+K, , Display the Devices pane, , Windows Logo+L, , Lock your computer, , Windows Logo+M, , Minimize all windows, , Windows Logo+O, , Turn the tablet orientation lock on and off, , Windows Logo+P, , Display the Project pane to configure a second display, , Windows Logo+Q, , Open Cortana for voice commands, , Windows Logo+R, , Open the Run dialog box, , Windows Logo+S, , Open Cortana for keyboard commands, , Windows Logo+T, , Activate the taskbar icons (use the arrow keys to navigate the icons), , Windows Logo+U, , Open the Ease of Access Center, , Windows Logo+W, , Activate the Search box, , Windows Logo+X, , Display a menu of Windows tools and utilities, , Windows Logo+Z, , Display an app's commands (although this works in only some Modern apps), , Windows Logo+=, , Open Magnifier and zoom in, , Windows Logo+-, , Zoom out (if already zoomed in using Magnifier), , Windows Logo+,, , Temporarily display the desktop, , Windows Logo+Enter, , Open Narrator, , Windows Logo+Left, , Snap the current app to the left side of the screen, , Windows Logo+Right, , Snap the current app to the right side of the screen, , Windows Logo+Up, , Restore a minimized app; maximize a restored app, , Windows Logo+Down, , Restore a maximized app; minimize a restored app, , Windows Logo+PgUp, , Move the current app to the left monitor, , Windows Logo+PgDn, , Move the current app to the right monitor, , Windows Logo+PrtSc, , Capture the current screen and save it to the Pictures folder, , Windows Logo+Ctrl+D, , Create a virtual desktop, , Windows Logo+Ctrl+Right, , Switch to the next virtual desktop, , Windows Logo+Ctrl+Left, , Switch to the previous virtual desktop, , Windows Logo+Ctrl+F4, , Close the current virtual desktop, , Windows Logo+Tab, , Open Task View, which displays thumbnails for each running app as well as, the available virtual desktops, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Windows Opeating System, , Related Theory for Exercise 1.3.12, , Handling printers, Objectives : At the end of this lesson you shall be able to, • explain about typewriter, • explain about printer, • explain types and cost of printers, • explain programming languages for printers, • explain how to locate printer driver files., Typewriter, A typewriter is a mechanical or electromechanical device, with keys that, when pressed, cause characters to be, printed on a medium, usually paper as on Fig 1. Typically, one character is printed per keypress, and the machine, prints the characters by making ink impressions of type, elements similar to the sorts used in movable type, letterpress printing., , Fig 2, , Fig 1, , Fig 3, , After their invention in the 1860s, typewriters quickly, became indispensable tools for practically all writing other, than personal correspondence. They were widely used, by professional writers, in offices, and for business, correspondence in private homes. By the end of the, 1980s, word processors and personal computers had, largely displaced typewriters in most of these uses., Computer printer, A printer is a piece of hardware for a computer as on, Fig 2. It is a device that must be connected to a computer, which allows a user to print items on paper, such as letters, and pictures. It can also work with digital cameras to, print directly without the use of a computer., Types of printers, Today, the following types of printers are in regular use:, Daisy wheel printing is an impact printing technology, invented in 1969 by David S. Lee atDiablo Data Systems, as on Fig 3. It uses interchangeable pre-formed type, elements, each with typically 96 glyphs, to generate highquality output comparable to premium typewriters such, , as theIBM Selectric, but two to three times faster. Daisy, wheel printing was used in electronic typewriters, word, processors and computers from 1972. According to, Webster's, the daisy wheel is so named because of its, resemblance to the daisy flower., , Copyright @ NIMI Not to be Republished, , 33
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Dot-matrix printers are now almost extinct. They used a, ribbon and made a lot of noise. There were models with, 9 pins and models with 24 pins as on Fig 4. A dot matrix, printer or impact matrix printer is a type of computer, printer with a print head that runs back and forth, or in an, up and down motion, on the page and prints by impact,, striking an ink-soaked cloth ribbon against the paper,, much like the print mechanism on a typewriter., , Fig 6, , Fig 4, , such wide-format printers as "plotters," even though they, technically are not., , Inkjet printing is a type of computer printing that creates, a digital image by propelling droplets of ink onto paper, as on Fig 5. Inkjet printers are the most commonly used, type of printer, and range from small inexpensive, consumer models to very large professional machines, that can cost tens of thousands of dollars., , Pen plotters print by moving a pen or other instrument, across the surface of a piece of paper. This means that, plotters are restricted to line art, rather than raster, graphics as with other printers. Pen plotters can draw, complex line art, including text, but do so slowly because, of the mechanical movement of the pens. They are often, incapable of efficiently creating a solid region of color,, but can hatchan area by drawing a number of close,, regular lines., Laser printing is a digital printing process that rapidly, produces high quality text and graphics on plain paper., As with digital photocopiers and multifunction printers, (MFPs), laser printers employ a xerographic printing, process, but differ from analog photocopiers in that the, image is produced by the direct scanning of a laser beam, across the printer's photoreceptor., , Fig 5, , A laser beam projects an image of the page to be printed, onto an electrically charged rotating drum coated with, selenium or, more common in modern printers, organic, photoconductors. Photoconductivity allows charge to leak, away from the areas exposed to light., , The concept of inkjet printing originated in the 20th, century, and the technology was first extensively, developed in the early 1950s. Starting in the late 1970s, inkjet printers that could reproduce digital images, generated by computers were developed, mainly by, Epson,Hewlett-Packard (HP), and Canon. In the, worldwide consumer market, four manufacturers account, for the majority of inkjet printer sales: Canon, HP, Epson,, and Lexmark, a 1991 spin-off from IBM., The plotter is a computer printer for printing vector, graphics as on Fig 6. In the past, plotters were used in, applications such as computer-aided design, though they, have generally been replaced with wide-format, conventional printers. It is now commonplace to refer to, 34, , Dry ink (toner) particles are then electro statically picked, up by the drum's charged areas, which have not been, exposed to light. The drum then prints the image onto, paper by direct contact and heat, which fuses the ink to, the paper., Cost of printers, There are different costs with a printer. Printers that are, more expensive to buy will usually be less expensive in, the consumables (the ink, toner, or ribbon used by the, printer). Therefore, laser printers are often more, expensive to buy than inkjet printers, but are not, expensive to use over a long period of time., Inkjet printers on the other hand have a higher cost of, consumables because the ink tanks they use are more, expensive than the toner for a laser printer., Laser printers that can print in color are usually more, expensive than those that only print in black and white., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished
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Other options, like being able to print on both sides of a, sheet of paper, to automatically sort the output, or to, staple the output will also make a printer more expensive., , Fig 7, , Common programming languages for printers, include:, ESC/P, , •, , Postscript, , •, , PCL, , •, , GDI, , •, , HPGL and HPGL/2, , •, , PDF, , Prominent features of a scanner include:, , •, , VPS, , •, , Reliability - Unlike certain forms of data transmission,, scanning involves only transfer of hard images to, digital forms. The role of the end-user is limited in, case of scanning. And as they are not dependent on, two-way communication, they can also help in storing, important information or transmitting important, information., , •, , Efficiency - Modern scanners are built for efficiency, and speed. And it comes with ease of use as well as, convenience., , •, , Quality - Scanning ensures the best resolution, possible for digital images. Compared to fax, machines, which may find it difficult to reproduce the, accurate details, scanners can reproduce images with, high resolution and precisions. They are quite useful, for photography and engineering arenas., , •, , Cost saving - One of the biggest advantage of, scanning is the replacement of physical files/forms, with digital ones. Along with saving physical space,, which has to be used for storage, there are also, environmental benefits by using scanner., , Copa 110107, , •, , How to Locate Printer Driver Files, Printers can be connected to a computer by a variety of, wired and wireless methods, but all printers require, drivers to be installed on a computer. The printer drivers, are small programs that help communicate information, from the operating system to the printer., Driver errors can make the printer unusable. Using the, Windows device manager, you can look up details about, the drivers as well as pinpoint their physical location on, your hard drive., Scanner, A scanner is an electronic device which can capture, images from physical items and convert them into digital, formats, which in turn can be stored in a computer, and, viewed or modified using software applications., Different types of scanners are available with different, resolutions. In the world of electronic data transmission,, scanning is considered to be the most cost-effective and, reliable way of transmitting images., The basic principle of a scanner is to analyze an image, and reproduce it to a digital one using the optical, character recognition techniques., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished, , 35
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IT & ITES, Related Theory for Exercise 1.4.13, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., The Basic Input/Output System (BIOS), also known as, System BIOS, ROM BIOS or PC BIOS is a generally, accepted standard defining a firmware interface., , •, , The fundamental purpose of the BIOS is to initialize and, test the system hardware components and load an, operating system from a mass memory device. The BIOS, is special software that interfaces the major hardware, components of the computer with the operating system., It is usually stored on a Flash memory chip on the, motherboard, but sometimes the chip is another type of, ROM. The BIOS is a firmware (software instructions, permanently recorded on a chip located on your, motherboard). (Refer Fig.1)., , The first thing the BIOS will do is check the information, stored in a tiny (64 bytes) amount of RAM located on a, complementary metal oxide semiconductor (CMOS), chip. The CMOS Setup provides detailed information, particular to your system and can be altered as your, system changes. The BIOS uses this information to, modify or supplement its default programming as, needed., , Copa 181301, , Fig 1, , Functions of BIOS, The BIOS software has a number of different roles, but, its most important role is to load the operating system., The BIOS checks and initializes the PC hardware each, time the system powers up or restarts before handing, over control to the operating system. Some of the other, common tasks that the BIOS performs include:, •, , A power-on self-test (POST) for all of the different, hardware components in the system to make sure, everything is working properly, , •, , Activating other BIOS chips on different cards installed, in the computer - For example the graphics cards often, have their own BIOS chips., , •, , Providing a set of low-level routines that the operating, system uses to interface to different hardware, devices. They manage things like the keyboard, the, screen, and the ports, especially when the computer, is booting., , 36, , Managing a collection of settings for the hard disks,, clock, etc., , CMOS Setup, , Configuring BIOS, The BIOS checks the CMOS Setup for custom settings., To change the CMOS settings we need to enter the, CMOS setup. To enter the CMOS Setup, a certain key, or combination of keys must be pressed during the initial, startup sequence. Most systems use "Esc," "Del," "F1,", "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. There is, usually a line of text at the bottom of the display that, tells "Press ___ to Enter Setup.", The BIOS setup shows a set of text screens with a, number of options. Some of these are standard, while, others vary according to the BIOS manufacturer., Common options include:, •, , System Time/Date - Set the system time and date, , •, , Boot Sequence - The order that BIOS will try to load, the operating system, , •, , Plug and Play - A standard for auto-detecting connected, devices; should be set to "Yes" if your computer and, operating system both support it, , •, , Mouse/Keyboard - "Enable Num Lock," "Enable the, Keyboard," "Auto-Detect Mouse"..., , •, , Drive Configuration - Configure hard drives, CD-ROM, and floppy drives, , •, , Memory - Direct the BIOS to shadow to a specific, memory address, , •, , Security - Set a password for accessing the computer, , •, , Power Management - Select whether to use power, management, as well as set the amount of time for, "standby" and "suspend", , Copyright @ NIMI Not to be Republished
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•, , Exit - Save your changes, discard your changes or, restore default settings., , The BIOS uses CMOS technology to save any changes, made to the computer's settings. With this technology, a, small lithium or Ni-Cad battery can supply enough power, to keep the data for years. Major BIOS manufacturers, include American Megatrends Inc. (AMI), Phoenix, Technologies, Winbond etc. A typical BIOS screenshot, is shown in fig. given below.(Refer Fig.2), Fig 2, , •, , Use of multi-boot setups, which allow users to have, more than one operating system on a single computer., For example, one could install Linux and Microsoft, Windows or other operating systems on different, partitions of the same HDD and have a choice of, booting into any operating system at power-up., , •, , Protecting or isolating files, to make it easier to recover, a corrupted file system or operating system installation., If one partition is corrupted, other file systems may not, be affected., , •, , Raising overall computer performance on systems, where smaller file systems are more efficient., , •, , Partitioning for significantly less than the full size, available can reduce the time for diagnostic tools such, as checkdisk to run., , Copa 181302, , Formatting, , Installing the Windows operating System, A hard disk needs to be partitioned (though not, mandatory) and formatted before you can store data, on it., Partitioning, A partition, sometimes also called a volume, is an area, on a hard disk that can be formatted with a file system, and identified with a letter of the alphabet. For example,, drive C on most Windows computers is a partition. the, first three partitions you create are primary partitions., These can be used to start an operating system. If you, want to create more than three partitions, the fourth, partition is created as an extended partition., An extended partition is a container that can hold one or, more logical drives. Logical drives function like primary, partitions except that they cannot be used to start an, operating system., Many computers are partitioned as a single partition that, equals the size of the hard disk. Partitioning a hard disk, into several smaller partitions is not required, but it can, be useful for organizing data on your hard disk., Creating more than one partition has the following, advantages:, •, , Separation of the operating system (OS) and program, files from user files., , •, , Having a separate area for operating system virtual, memory swapping/paging., , •, , Keeping frequently used programs and data near each, other., , Disk formatting is the process of preparing a data storage, device such as a hard disk drive, solid-state drive or, USB flash drive for initial use. It is the act of creating a, file system on a volume, so that the operating system, can store and retrieve data on that volume., Formatting of a disk is of two categories:, 1 Low-level formatting (i.e., closest to the hardware), marks the surfaces of the disks with markers, indicating the start of a recording block. It also, provides information about block checks done for, future use by the disk controller to read or write data., This is intended to be the permanent foundation of, the disk, and is often completed at the factory. A hard, disk needs to be partitioned and formatted before you, can store data on it, 2 High-level formatting creates the file system format, within a disk partition or a logical volume. This, formatting includes the data structures used by the, OS to identify the logical drive or partition's contents., This may occur during operating system installation,, or when adding a new disk., Installing the Windows operating System, The three basic types of windows installation procedures, are as follows:, •, , Install on a brand new disk or computer system, , •, , Erase the disk, format it, and install., , •, , Install into a new directory for dual-booting, , For the first two methods, it must be ensured that the, computer can boot from a DVD or any other removable, drive. To do this the drive boot order needs to be changed, in the BIOS. The latest Windows DVDs are bootable, and run the Setup program automatically. Then the, installation can be done by following the procedure step, by step as indicated on the subsequent screens as in, trade practicals., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.13, , Copyright @ NIMI Not to be Republished, , 37
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IT & ITES, Related Theory for Exercise 1.4.14 & 1.4.15, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., Format a hard drive, , Format hard drive partitions, It's important to understand about partitions before getting, started. A hard drive can be divided up into smaller, sections, called partitions. It's possible to format one, partition while leaving the others untouched., , Fig 1, , If it isrequired to format the entire hard drive and use the, entire capacity in one block, delete the partition, information., Format a hard drive from the BIOS?, , Copa 110101, , Many people ask how to format a hard disk from BIOS., The short answer is no., , There are many reasons why it is required to format a, hard drive, such as to install Windows fresh, to get rid of, a virus or malware or simply because a pc is refreshed, or cleaned up on selling., , If it is required to format a disk and you can't do it from, within Windows, create a bootable CD, DVD or USB flash, drive and run a free third-party formatting tool., One option is Darik's Boot and Nuke (DBAN), which is, free for personal use. This program will totally erase and, format your hard disk, allowing for a clean install of a, new OS, but the process cannot be undone., Fig 2, , The process can be different depending on whether it's, an only hard drive and whether there is a spare PC or, not., , Copa 110102, , It cannot be formatted, the hard drive on which Windows, is running. In order to do this, it is in need to boot the PC, from a Windows installation disc, a USB flash drive or, another bootable disc., Format a disk?, Formatting is the process of deleting all the data on the, hard drive, but beware of 'Quick Format' which leaves, all data in place and makes the drive appear to be empty., A quick format is ok if there is a brand new hard drive, or, need to reinstall Windows, but not if its disposing of the, disk or giving it to someone else., , DBAN is supposedly only able to create a bootable CD/, DVD-R, but if don't have any blank discs or a burner,, there is a workaround available in the form of a separate, third-party program., , A word of warning: make sure to have successfully, backed up any photos, videos, music and other, documents from the drive before formatting it. Although, deleted files can be recovered in some situations,, prevention is always better than cure., , Universal USB Installer will quickly and easily convert, the DBAN ISO image downloaded to run from a bootable, USB. Simply insert a blank USB flash drive, run the, Universal USB Installer setup program, and follow the, prompts., It will ask to scroll through and pick the Linux Distribution, want to install to USB (in this case, the latest version of, DBAN), followed by its location on the computer and the, letter of the USB drive like to install it to., , 38, , Copyright @ NIMI Not to be Republished
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Once that information is complete, click create., , Copa 191503, , To boot from this USB drive rather than usual boot device, (in most cases, this would be the hard drive), it have to, be changed some settings in the BIOS., In the BIOS, navigate to the boot order settings, and, change the primary boot device to the USB drive (it, shouldn't need to be plugged in to make this selection)., After saved the settings and exited the BIOS, insert the, bootable USB, restart the computer., , Copa 191505, , Fig 5, , Fig 3, , By default Quick Format is checked, and choose the file, system and allocation unit size as well as changing the, volume label (the drive's name). Typically, leave all, settings unchanged and click the Start button. In under a, minute the hard drive will be formatted., , Fig 6, , Copa 191504, , Fig 4, , It will treat the USB as another drive so to avoid, inadvertently wiping that as well, remove it after booted, into DBAN., Quick format a hard drive?, Yes, but don't use this method if want the data to be, permanently erased. A quick format doesn't delete the, data but instead erases only the pointers to the files., Windows Vista, 7, 8 and 10 have a built-in Disk, Management tool (see below), but the fastest way to, format a hard drive is to click the Start button, then, Computer and right-click on the hard drive to wipe. It, can't be formatted the drive on which Windows is installed, for obvious reasons., , Copa 191506, , The PC should automatically boot the DBAN software,, which will guide through the process of erasing the hard, drive, with options for different levels of data-wiping., , Choose NTFS as the file system if it isn't already selected, for Windows Vista, 7, 8 or 10 and ensure the Allocation, Unit Size is set to 'Default Allocation Size'., Using the Disk Management tool, Type diskmgmt.msc or Disk Management into the search, box in Vista, 7, 8 or 10 and then click on only result that, appears in the menu above, with the same name., This is the easiest way to launch Disk Management, but, also find it in the Control Panel if search for 'disk' and, select the 'Create and format hard disk partitions'., Disk Management isn't as powerful as a standalone, partition management tool, but it is still capable of, formatting data., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 39
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If select a size for the partition that's smaller than the total, capacity of the drive, say 500B on a 1TB drive, end up, with some unallocated space on the drive which can format, by repeating the process just completed., , Fig 7, , change partition size, Disk Management can be used to expand or shrink a, partition. Simply right-click on one and choose the, appropriate option from the menu that appears. If, shrinking, the partition will be checked to find out how, much empty space it contains., , If it is to install a new (additional) hard drive in a PC, it, might be a thing to wonder why it doesn't appear in Windows, Explorer. The reason is because it needs to be initialised, and formatted -which can be done in Disk Management., When the tool loads, it will analyse all of the computer's, drives and will prompt to initialise a new disk that it finds., , Fig 8, , Copa 191509, , Copa 191507, , Fig 9, , It's a little confusing as the numbers are displayed in MB, rather than GB, but it can be adjusted the amount of, space to shrink and the 'Total size after shrink' will be, updated, alsocan't shrink a partition beyond the point, where files are located - it may be able to free up space, by defragmenting the drive first., Conversely it can only expand a partition if there is, unused space on the drive. If not, the option will be greyed, out., , Copa 191508, , Resetting Windows, If PC is having problems and the user don't wish to lose, the personal files by wiping the hard drive, then it might, want to refresh or reset the PC which can be done in, Windows 8 and 10., If user looking to keep your personal files and settings,, but want to have a fresh Windows install, itsall want to, refresh the PC., , If the disk is larger than 2TB, opt for GPT (GUID Partition, Table). This setting also lets to create more than four, partitions., , Do note that a refresh will remove all programs and apps, installed on the machine, but will keep the Windowsdefault programs intact., , If don't see a prompt, look in the list of drives and see, one that says 'Not Initialized'. Right-click on it and choose, Initialize Disk., , A reset reinstalls Windows and deletes all files, settings, and programs, it is suggested performing this if have, previously backed up all the files and don't mind, transferring user's personal files., , Once that's done, right-click in the hatched Unallocated, space and choose New Simple Volume…, Follow the instructions, choosing how big to want the, partition to be (in MB - 1024MB = 1GB), and which drive, letter to assign (one will be chosen, but can opt to change, it if desired)., , 40, , Windows 10 has a slightly different approach and might, confuse those coming from Windows 8. Microsoft, removed the refresh option and has instead combined, the refresh and reset options into one setting., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished
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Copa 1915010, , Fig 10, , To find the option, open the Start Menu, click on Settings, > Update & security > Recovery > Get started (under, the Reset this PC option)., , 'Keep my files' saves personal files but deletes user, settings, drivers and programs, whilst also reinstalling, Windows 10., , Upon selecting the option, it will present with three, separate options:, , 'Remove everything' also gets rid of personal files and, 'Restore factory settings' does the same actions as, 'Remove everything', but also resets the PC to the version, of Windows which came with the machine., , •, , Keep my files, , •, , Remove everything, , •, , Restore factory settings (not available on all PCs), , This option will only be available to those who bought a, pre-built PC or laptop which came with Windows already, pre-installed., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 41
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IT & ITES, Related Theory for Exercise 1.4.16, COPA - Computer basics & Software installation, Troubleshooting computer, Objectives: At the end of this lesson you shall be able to, • state the basic steps involved in troubleshooting a PC, • explain the basic approach to solve a problem, • list the probable defects and symptoms in a faulty Computer, • analyse the causes for the complaints, • state the shortest path for servicing the defects., • list the probable defect and symptoms in the faulty Computer, • analyse the causes for the complaint “When windows is started, system runs surface test and goes to, safemode” with the help of a Problem Tree and TSC, Basic Troubleshooting, One of the difficulties while troubleshooting problems on, a PC is that in most cases they are not what they seem., The cause behind a frequent hanging of a PC may be due, to one of six or more well defined areas or a dozen of, unidentified problems. The problem could be due to, software or hardware. Even with years of experience and, training, PC technicians come out with troubleshooting, procedures that do not solve the real problem. For, example a personal computer running windows operating system with several i/o cards connected may freeze, the screen , mouse, and keyboard and take as long as 3, minutes before responding. After trying out with all the, options like replacing a memory module, installing new, parallel port and NIC drivers, the technician finally checks, the system logs to find that a vital operating system, library was corrupted and needed to be reinstalled. The, issue to be mentioned here is that if the technician used, a systematic approach to troubleshooting, the problem, would likely have been solved much sooner. Maintaining, a good troubleshooting plan certainly gives us the scope, to approach the problem in a more systematic and, scientific manner. A troubleshooting plan is nothing but, a written check list that we use for any problem. The, elements that should be included in any troubleshooting, plan are as follows, – Maintenance record, – Identification of possible causes, – Identification of possible solutions, – Application and testing of solutions, – Follow-up, In the maintenance record, record the hardware installed, in the PC when it is installed, all preventive maintenance, activities, all software updates or additions, and all, hardware installations and upgrades. Further any problems that occur and the actions you take to resolve them, should be recorded . when it comes to troubleshooting a, PC, with the maintenance record one can pin down a, problem and devise solution for it. The first entry in such, record should be a profile of the PC, which includes its, configuration, operating system, and the date each, component was installed., 42, , Such tables gives an idea of the type of information one, should include in the sytem configuration, as summerised, below:, – The processor’s make, model and speed., – Amount of system memory(RAM) and the memory, module type, size and configuration of the memory, – Hard disk size and the type of interface, – Make, model and speed of the compact disk (CD) or, digital versatile disk ( DVD) drive, – Memory size of the video or graphics adapter, – Make, model, type and speed of the modem, – The version number of the operating system, – A list of software applications installed on the PC, – A list of peripheral equipment attached to the PC,, indicating the port to which they are attached, The maintenance record should be updated each time any, maintenance work is carried over on the PC. Any time new, or replacement hardware is installed, record the activity, and update the system configuration. The activity entries, should include, – Date of the activity or changes made to the system, – The make, model and serial number of any hardware, removed or added to the PC, – The name, version and publisher of any software added, to the PC, – Detailed information on any configuration changes, made to the basic input/output system(BIOS) or other, configuration for the new device or software., Troubleshooting approach, For solving any problems associated with PC, first go, through the maintenance record of that PC and follow a, systematic procedure for isolating the problem. The, standard problem solving process includes the following, steps, Identify the problem: This is the most difficult part of the, process. To perform this step successfully collect all the, data about the problem, , Copyright @ NIMI Not to be Republished
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Identify possible causes: analyse all the symptoms of, the problem and try to list all the causes in order from the, most likely to the least likely., Identify possible solutions: identify solutions for each of, the causes that are identified. A possible cause could have, more than one possible solution., Analyze the possible solutions: if two solutions produce the same result, consider the one which is more, economic and apply the same., After following the above steps and on solving the, problem update the maintenance record and make, necessary entries into it. In some cases the problems, may be very clear and the solution is very transparent and, even in such cases try to follow the above mentioned steps, to make it a practice to follow the systematic approach., Whenever a problem occurs with a PC, while following the, steps, try to collect the information about the system by, answering questions such as, – Under what circumstances this problem cropped up?, – Were there any indications in the form of beep codes/, error messages or any clear symptoms?, – What softwares were active when the problem happened?, – Has it happened for the first time or occurred in the past, also?, – Were there any configuration changes made during, the session that required a restart that was not, performed?, Optimizing the PC:, A PC which was functioning absolutely well and developed, a symptom of slowing down or if it is unable to keep pace, with the demands of newer software, one of the possible, solutions is to consider updating or optimizing the PC to, enhance its performance. Optimization steps may cost, money , but many involve software you already own or, software readily available on the web., , they are installed out of order, but there is some benefit to, be gained from putting them in the proper sequence. On a, Pentium system, use PCI cards and avoid ISA cards, if, possible. All I/O adapters including video cards, sound, cards, NICs, modems and SCSI adapters are available for, the PCI expansion bus. Consult the motherboard documentation and install video card in the first PCI slot,, followed by the NIC, modem, and sound card, in that order., Optimizing the processor: One can speed up the processor in the following ways, – Replace it with a faster speed or higher level processor, – Use a utility from the processor manufacturer to apply, patches or fixes to the processor’s logic, – Overclock the processor, The requirement for replacing the processor with a higher, level or faster processor is that your motherboard and, chipset will support the new processor both logically and, physically. Logically the chipset and motherboard must, support the bus speed of the processor and have the, supporting circuits it requires. It is often much better to, replace the complete motherboard. Some times the manufacturer of the processor may release some utilities that, will improve some aspect of processor’s capabilities such, as video processing, buffer handling, caching and other, processor based functions. Overclocking a processor, means running a processor at speeds faster than it was, released to support. Most processors are capable of, running at speeds higher than their nominal speeds. The, nominal speed of a processor is the speed at which it has, been tuned to run with a certain chipset, motherboard,, cooling system, and other components of the PC. Raising, the speed of the processor can create heating problems on, the processor and lead to frequent system lockups,, memory problems and other issues., Troubleshooting sources of Non-software problems:, Any time pc fails for no apparent software reason, check, the following areas, , Optimizing the BIOS and Boot process:, , – Ensure proper AC power, , BIOS setup configuration includes many settings in the, CMOS. How quickly the system boots and performs, depends on the these settings. Enabling of valuable, features such as system caching or using the quick, POST process are very vital for optimum peroformance., , – Scan the PC for a computer virus, , Optimizing the hard disk: Windows ScanDisk and Disk, Defragmenter utilities are the best tools available for, optimizing the hard disk in terms of usage and access, speeds. ScanDisk is used to check a disk for errors and, repair them or remove unrecoverable areas of the disk, from the usage tables to prevent future errors. Similarly, Disk Defragmenter organizes data file fragments into a, more optimized and logical format that provides for, faster access times and less head movement., Optimizing the Expansion cards: The best way to, optimize I/O controllers and other expansion cards is to, install them in the correct order. No harm is done even if, , – Ensure that CPU fan is spinning, – Ensure proper connections of external I/O connectors, – Reseat the expansion cards and check the power and, data cables of internal devices, – Most of the boot problems are the result of a recent, change, check out the BIOS setup configuration data, – To install any new hardware or software, visit manufacturer’s web site for any known conflict or incompatibility, – Check for any resource conflict if any new hardware or, software is installed., The forth coming lessons on Troubleshooting PC are, provided with Problem Trees for different type of problems, which a user face normally. Each Tree with a specific, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 43
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problem gives scope to analyse the areas to be suspected, or looked into for fixing the problem. This lesson includes, a Problem Tree for a PC which is Dead with no display on, monitor., PROBLEM TREE : PT- 01, Observed symptom, , : Dead, , Additional symptom, , : No display, , PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”., Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , 44, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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SAFE MODE, SURFACE SCAN TEST, , HDD, BAD SECTORS, , OS, , Discuss the Troubleshooting chart (TSC-01) and Service flow sequence (SFS-01) for the complaint “When, windows is started system runs surface test and goes to safemode” referring to exercise 2.33, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 45
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PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , Observed symptom, , PROBLEM TREE : PT- 03, : DVD drive can’t read, , Additional symptom, , :, , 46, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.17, COPA - Computer basics & Software installation, Application softwares, Objective: At the end of this lesson you shall be able to, • describe various software types., Application software, Application software is a term which is used for software, created for a specific purpose. It is generally a program, or collection of programs used by end users. It can be, called an application or simply an app., In fact all the software other than system software and, programming software are application software., Application software definition, A software which is developed to help the user to perform, specific tasks is called application software., The different types of application software include the following:, Application Software Type, , Examples, , Word processing software, , MS Word, WordPad and Notepad, , Database software, , Oracle, MS Access etc, , Spreadsheet software, , Apple Numbers, Microsoft Excel, , Multimedia software, , Real Player, Media Player, , Presentation Software, , Microsoft Power Point, Keynotes, , Enterprise Software, , Customer relationship management system, , Information Worker Software, , Documentation tools, resource management tools, , Educational Software, , Dictionaries: Encarta, BritannicaMathematical:, MATLABOthers: Google Earth, NASA World Wind, , Simulation Software, , Flight and scientific simulators, , Content Access Software, browsers, , Accessing content through media players, web, , Application Suites, , OpenOffice, Microsoft Office, , Software for Engineering and Product Development, , IDE or Integrated Development Environments, , Copyright @ NIMI Not to be Republished, , 47
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There are various different types of application software, such as licensed, sold, freeware, shareware and open, source., Application software's either need to be installed or can, run online. Application software's can also be distinguished, on the basis of usage into the following:, •, , Utility programs, , •, , Generic programs, , •, , Integrated programs, , •, , Specific software, , •, , Bespoke software, , •, , Word processing software, , 48, , •, , Desktop publishing software, , •, , Spreadsheet software, , •, , Database software, , •, , Presentation software, , •, , Internet Browsers, , •, , Email Programs, , •, , Graphic Programs (Pixel based), , •, , Graphic Programs (vector based), , •, , Communication software: Communication through, audio, video or chat based means, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.17, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.18&1.4.19, COPA - Computer basics & Software installation, Bluetooth devices, Objectives : At the end of this lesson you shall be able to, • describe the meaning of Bluetooth, • describe the method of using Bluetooth, • list the major applications of Bluetooth., Introduction:, Bluetooth is a wireless technology standard for, exchanging data over short distances (using shortwavelength UHF radio waves in the range 2.4 to 2.485, GHz) from fixed and mobile devices, and building, personal area networks (PANs). It is a standard wirereplacement communications protocol primarily designed, for low-power consumption, with a short range based on, low-cost transceiver microchips in each device., It can connect up to eight devices (items of electronic, equipment) at the same time. The chip can be plugged, into items such as computers, digital cameras, mobile, phones and faxes. Bluetooth is particularly convenient, in certain situations - for example, when transferring files, from one mobile phone to another without cables., Sending music and photos between a PC and a mobile, phone is another useful application., Because the devices use a radio (broadcast), communications system, they do not have to be in visual, line of sight of each other, however a quasi optical, wireless path must be viable., Range is power-class-dependent, but effective ranges, vary in practice varying from 10 to 100 m., The name 'Bluetooth' reflects the Scandinavian origins, of the technology. It is named after a 10th century Danish, viking, King Harald Blåtand (translating as 'Bluetooth' in, English).He united and controlled Denmark and Norway,, hence the association of uniting devices through, Bluetooth., , When devices like mobile phones, laptops, tablets etc., enable Bluetooth the Bluetooth icon is on., To establish a Bluetooth connection:, 1 Find the file you wish to send., 2 Select the option to send it via Bluetooth - your device, will search for other devices within range and display, them., 3 Scroll to the device you wish to connect with and, select it., 4 If the other device needs 'pairing', you will need to, enter a passcode - a bit like a PIN number - and make, sure it is entered on the other device., When the connection is established, the data will start to, send. You do not need worry about a clear line of sight, between devices., List of Bluetooth applications, Some of the Bluetooth applications are as follows:, Wireless control of and communication between a mobile, phone and a handsfree headset.(Refer fig. 1), , Fig 1, , To use Bluetooth, the device must be Bluetooth enabled., For this purpose a device called "Dongle"may be used., A dongle is a device that plugs into the computer to, enable it to use Bluetooth. Every manufacturer of, compatible devices will have their own instructions for, accessing Bluetooth. For detailed instructions you will, need to see the manual, but as a general guide:, To set up Bluetooth:, (Identify the blue tooth icon on devices.), 1 Turn on, or enable, Bluetooth. Ensure your device is, 'visible' and not 'hidden', so other nearby devices can, pick up the signal., 2 Give your device a name to identify it when, connecting to other compatible equipment., , Copa 118290A1, , Using Bluetooth, , • Wireless control of and communication between a, , mobile phone and a Bluetooth compatible car stereo, system., , • Wireless control of and communication with tablets, and speakers such as iPad and Android devices., , • Wireless networking between PCs in a confined space, and where little bandwidth is required., , • Wireless communication with PC input and output, , devices, the most common being the mouse,, keyboard and printer., , Copyright @ NIMI Not to be Republished, , 49
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• Transfer of files, contact details, calendar, , appointments, and reminders between devices with, OBEX(Objects exchange)., , • Replacement of previous wired RS-232 serial, , communications in test equipment, GPS receivers,, medical equipment, bar code scanners, and traffic, control devices., , Wi-Fi:, Wi-Fi is a popular wireless networking technology. WiFi stands for "wireless fidelity". The Wi-Fi was invented, by NCR corporation/AT&T in Netherlands in 1991. By, using this technology we can exchange the information, between two or more devices. Wi-Fi has been developed, for mobile computing devices, such has laptops, but it is, now extensively using for mobile applications and, consumer electronics like televisions, DVD players and, digital cameras. There should be two possibilities in, communicating with the Wi-Fi connection that may be, through access point to the client connection or client to, client connection. Wi-Fi is a one type of wireless, technology. It is commonly called as wireless LAN (local, area network). Wi-Fi allows local area networks to, operate without cable and wiring. It is making popular, choice for home and business networks. A computer's, wireless adaptor transfers the data into a radio signal, and transfers the data into antenna for users., , Fig 1, , • Wireless bridge between two Industrial Ethernet, networks., , • Wireless controllers in gaming consoles., • Personal security application on mobile phones for, prevention of theft or loss of items. The protected, item has a Bluetooth marker (e.g., a tag) that is in, constant communication with the phone. If the, connection is broken (the marker is out of range of, the phone) then an alarm is raised., , And can now generate a system within Resorts, library,, schools, colleges, campus, personal institutes, as well, as espresso stores as well as on the open public spot to, help to make the company much more lucrative as well, as interact with their own customer whenever. Wi-Fi, compatibility can make surf with stare to company using, their inspiring cable television much a smaller amount, force down., The radio signals are transmitted from antennas and, routers that signals are picked up by Wi-Fi receivers,, such has computers and cell phones that are ready with, Wi-Fi cards. Whenever the computer receives the signals, within the range of 100-150 feet for router it connect the, device immediately. The range of the Wi-Fi is depends, upon the environment, indoor or outdoor ranges. The, Wi-Fi cards will read the signals and create an internet, connection between user and network. The speed of the, device using Wi-Fi connection increases as the computer, gets closer to the main source and speed is decreases, computer gets further away., , Copa 1121802, , Copa 1121801, , Fig 2, , Working Principle:, Wi-Fi is a high speed internet connection and network, connection without use of any cables or wires. The, wireless network is operating three essential elements, that are radio signals, antenna and router. The radio, waves are keys which make the Wi-Fi networking, possible. The computers and cell phones are ready with, Wi-Fi cards. Wi-Fi compatibility has been using a new, creation to constituent within the ground connected with, community network. The actual broadcast is connected, with in sequence in fact it is completed by way of stereo, system surf as well as the worth of wires with monitor to, classification prone. Wi-Fi allows the person in order to, get access to web any place in the actual provided area., , 50, , Security:, Security is impartment element in the Wi-Fi technology., Security is our personal decision but having a wireless, connection we should pay attention to protect our private, details. We can connect easily to unsecured wireless, routers. The problem is any one is connected to, thewireless router using the data like download games,, download apps and planning terrorist activities, shirring, illegal music and movie files etc. So it is necessary to, provide security to the wireless technologies based, devices., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.18 & 1.4.19, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.20, COPA - Computer basics & Software installation, DVDs, CDs and burning DVDs, Objectives : At the end of this lesson you shall be able to, • describe the features of CDs & DVDS, • describe the main formats of DVDs, • describe DVD burning, • describe the features of CDs., Introduction, DVD (sometimes called as "digital video disc" or "digital, versatile disc") is a digital optical disc storage format., DVDs can be usedwith many types of players, including, PCs and standalone players., These discs are known as DVD-ROM, because data can, only be read and not written or erased. Blank recordable, DVD discs (DVD-R and DVD+R) can be recorded once, using a DVD recorder and then function as a DVD-ROM., Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM), can be recorded and erased multiple times., DVD features and formats, DVDs are used in DVD-Video consumer digital video, format and in DVD-Audio consumer digital audio format., They can also be used in a special AVCHD format (, Advanced Video Coding High Definition) often used with, AVCHD format camcorders. DVDs containing other types, of information may be referred to as DVD data discs., A typical recordable DVD can hold about 4.7 gigabytes, (GB). However, the total amount of disc space that you, can use to burn files to the disc is less than the amount, that's often listed on the disc itself. This is because the, disc capacity is calculated differently when it's used in a, computer. For example, a typical DVD-R that has a listed, disc capacity of 4.7 GB can only store about 4.37 GB of, data on the disc. DVDs offer a storage capacity of, approximately 4.7 GB. DVD discs do not deteriorate over, time and are unaffected by magnetic fields., The type of recordable disc to be used depends on a, few different factors, such as:, , • The types of recordable discs that work with the disc, burner., , • The disc drive on the computer or device will read, the disc after it is burned., , • The total size of all the files that will be burned on to, a disc., , DVD burning, The process of recording source material onto an optical, disc (CD or DVD) is called burning / writing or optical, disc authoring.Creating an optical disc usually involves, first creating a disk image with a full file system designed, for the optical disc, and then actually burning the image, to the disc. Many programs are available as bundled, applications to create the disk image and burn the files., , The speed at which a DVD can be written is expressed, as a multiplier: 16X means 16 times faster than just, playing it. Speeds upto 52X are also very common., CD or DVD formats, For burning DVDs, the two main disc formatsin use are:, , • Live File System and, • Mastered disc formats., Live File System format :, Discs that use the Live File System format are often, more convenient because you can copy selected files, immediately and as often as you want, just like you can, with a USB flash drive. This is convenient if you want to, keep a disc in your CD, DVD, or Blu ray Disc burner and, copy files whenever the need arises. In this format you, can copy and erase files over and over again. However,, the Live File System optical disc format is only readable, by Windows 7, Windows Vista, and Windows XP, systems. These discs are not blank after they're, formatted., Discs formatted in this format have the option name in, the Burn a Disc dialog box: "Like a USB flash drive.", Mastered disc formats:, If we want to create an optical disc that can be used to, transfer data files to older versions of the Windows, operating system or even to another operating system,, weneed to use the Mastered optical disc format. Also if, we want to burn music or pictures and use the disc in, regular CD, DVD, or Blu ray Disc players that can play, MP3 files and show digital pictures, we should use the, Mastered optical disc format., The Mastered format works just like burning CDs in, Windows XP. In other words, when we write the disc, we, copy a file or a group of files to the optical disc all at, once. Once this is done, the disc is closed and we cannot, copy more files to the disc nor can we delete the existing, files.Hence it is recommended not to copy files, immediately; it is a good practice to assemble the entire, collection of files that needed to be copied to the disc, and then burn them all at once., Discs formatted with the Mastered option have the option, in the Burn a Disc dialog box: "With a CD/DVD player.", There are many types of tools available to create data,, music, video and audio discs. We can also create, , Copyright @ NIMI Not to be Republished, , 51
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backups that span across multiple discs, rip music tracks, from Audio CDs and create or burn disc images in, different formats. They may also provide features like, automatic audio conversion from WAV, MP3, FLAC,, WMA files, disc copying, compressed file backup and, restore, disk erasing, VCD/SVCD support, project burning, etc.., , The following formats are part of the present day Bluray Disc specification:, , Blu - ray Discs, , 3, , Blu-ray, also known as Blu-ray Disc (BD) is the name of, a new optical disc format that is rapidly replacing DVD., The format was developed to enable recording, rewriting, and playback of high-definition video (HD), as well as, storing large amounts of data. The format offers more, than five times the storage capacity of traditional DVDs, and can hold up to 25GB on a single-layer disc and 50GB, on a dual-layer disc., , 1 BD-ROM - read-only format for distribution of HD, movies, games, software, etc., 2 BD-R - recordable format for HD video recording and, PC data storage., BD-RE - rewritable format for HD video recording, and PC data storage., , At present, a single-layer disc can hold 25GB and a duallayer disc can hold 50GB. Over 9 hours of high-definition, (HD) video on a 50GB disc. About 23 hours of standarddefinition (SD) video on a 50GB disc., , The name Blu-ray is derived from the underlying, technology, which utilizes a blue-violet laser to read and, write data. The name is a combination of "Blue" (blueviolet laser) and "Ray" (optical ray). They are referred to, as "Blu-ray" discs or BDs., , 52, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.20, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.21, COPA - Dos & Linux operating systems, Comand line interface with DOS, Objectives: At the end of this lesson you shall be able to, • describe the hierarchical directory system in DOS, • use dos commands to create directories and subdirectories, • use dos commands to change and list directory, • use dos commands to access specific files., Hierarchical Directory System: Hierarchy in simple, terms, is, organisation or an arrangement of entities., Entities can be anything such as objects, files, people,, ideas, or any other thing., Arrangement refers to, for example, Currency can be, arranged by denomination. Pebbles can be arranged by, their size ., There are many other ways to organize entities besides, hierarchically. But, hierarchical organization is special, because by this arrangement you can name each entity, by its relationship to other entities., In DOS, entities are the Directories in a directory system., Here, the hierarchy begins with the essential core or root, entity. For instance, in a family tree, we may consider, great-great-grand father who was the root cause of our, existence as the core entity. In DOS , this core entity is, referred to as the the root directory., As in the example considered above, if we consider, great-great-grand father as the root directory, then, greatgrand father, grand father, father are referred as sub, directories. So the directories under the root directory are, called subdirectories in DOS. These subdirectrories can, trace their paths back to the root directory., , In a family tree, say, Govinda is the son of Rajappa, who, is son of Ramappa who is son of Venkappa. Venkappa, is the head or root of the family tree for Govinda., One can create many directories from the root. The root, will then be the parent of each of these directories. You, can also create subdirectories that stem from other, subdirectories that stem from other subdirectories and so, on. These new subdirectories have a subdirectory as, their parent directory. How subdirectories are arranged, hierarchically from the root is illustrated in Fig 1. The, DOS directory system is often called a tree-structured, directory system., Three levels of subdirectories are represented in Fig 1., Regardless of the number of levels, the relationship of, the subdirectories is important. Each subdirectory, as, well as the root directory, can contain user files. Two files, can have the same file name and extension as long as the, files reside in different directories. This is because, DOS, needs to know which of two same-named files your, command specifies. For this, DOS needs the name of the, directories,starting from the root, that lead to the desired, file. This sequence of directory names leading to a file is, called a path., , The DOS hierarchical file system is called a tree-structured, file system. At the base of this tree structure is the root, directory., Fig 1, , ROOT, , a1, , LEVEL - 2, , LEVEL - 3, , B, , A, , LEVEL - 1, , a11, , a2, , a21, , D, , C, , c1, , c2, , c21, , Copyright @ NIMI Not to be Republished, , a22, 53
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A path is a chain of directory names that tell DOS how to, find a file that you want. Each directory is seperated from, the other by a ‘ \ ’ character. This ‘ \ ’ is referred to as the, DOS directory delimiter. A files full path name including, the drive specifier ( C: or D: etc.,) is the absolute indicator, of where the file is located. Typical path notation are, given below;, D:\Animals\Domestic\Pets\Dog.txt, C:\Admin\Accounts\Tours\Bata.txt, Further details of path and directory structure, will be discussed at appropriate lessons., DOS COMMANDS, 1, , MKDIR, , Makes or Creates a new Directory., , MKDIR\Drivers, Or, MD\Drivers, C:\Devices>MD \Printers, This instruction creates a subdirectory by name Printers, under the current drive C:. Note that although the, command is issued from another subdirectory named, devices, the newly created subdirectory Printers does, not get created under the directory Devices but directly, under the root C:. This may be verified by issuing DIR, command under C:\ and under C:\Devices., To create a subdirectory under the directory Devices the, instruction will be,, C:\Devices>MD Printers, Discuss the following different varieties of creating, directories:, , or, MD, , C:\Devices\Printers>MD C:\Devices\Plotters, , Syntax, MKDIR C:path\dirname, Or, , 2, , CHIDR or CD, , Changes or shows the path of the current directory., Syntax, , MD d:path\dirname, , CHIDR d: path, , Where,, C: is the disk drive for the sub directory, path\ indicates the path to the directory that will, hold the subdirectory being created., dirname is the name of the subdirectory being, creating., Switch, (None), Important Notes, – MKDIR or its short form MD makes new, subdirectories under the selected root directory., – It is possible to create as many subdirectories as, you want , but remember: DOS accepts no more, than 63 characters, including backlashes, for the path, name., – Do not create too many levels of subdirectories and, with long names., – You cannot create a directory name that is identical to, a file name in the current directory., For example, if you have a file named FLIES in the, current directory, you cannot create a subdirectory by the, name FLIES in this directory. However, if the file FLIES, is given an extension FLIES. DOC , then the names will, not conflict and you can create a subdirectory by name, FLIES., Examples, , Or, using the short form:, CD d : path, D : path are valid disk drive and directory names., Switch, (None), You have two methods for maneuvering through, the hierarchical directories with CD: (1) starting, at the root , or top, directory of the disk and, moving down, or (2) starting with the current, directory and moving in either direction., To start at the root directory of a disk, you must begin the, path with the path character (\), as in \ or B:\. When DOS, sees \ as the first character in the path, the system starts, with the root directory. Otherwise, DOS starts with the, current directory., Changing Drives: Computer will have built in memory,, the hard disk and it will also have provision to store/read, data from floppy disk, compact disk etc. Every disk is, identified by a name such as C drive, A drive, B drive etc., C drive is represented by C: and A drive is represented, by A: and so on. DOS allows to change from current or, default drive by typing the letter identification of disk, drive desired followed immediately by a colon as shown, in the example below:, C\> a:, , To create the subdirectory by name Drivers under the, current drive, the instruction will be,, 54, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished
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This command instructs to change control from C drive to, D drive., , H Hidden files, , If the disk drive is not accessed due to non availability of, floppy or any other reason, DOS will display an error, message, , A Files ready to archive - Prefix meaning “not”, , S System files, / O List be files in sorted order., sorted N By name (alphabetic), , Not ready error reading drive A, , S By size (smallest first), , Abort, Retry, Fail ?, , E By extension (alphabetic), , It is required to press either A,R or F keys, which are, defined below, , D By date & time (earliest first), G Group directories first, , A Directs DOS to abort the command that was, responsible for the error. If this option is selected, DOS will terminate the command and redisplay, prompt., , - Prefix to reverse order, C By compression ratio (smallest first), , R Directs DOS to retry the command that caused the, error. In most cases this option is selected to correct, the the problem that was causing the error. (Floppy, disk might not be inserted)., , /S, , Displays files in specified directory and all, subdirectories., , /B, , F Directs DOS to ignore the error and attempt to, continue processing. In some cases DOS will have, an error when it reads a portion of disk., , Uses bare format (no heading information or, summary)., , /L, , DOS COMMAND, DIR, , Displays a list of files and subdirectories in, a directory., , Syntax, DIR C:path/filename [/P] [/W] [/A[[:]attribs]] [/O[[:]sortord]], [/S] [/B] [/L] [/C[H]], , Where,, –, , C: is the disk drive holding the directory for, displaying list of files and subdirectories, , –, , path/ specifies directory and/or files to list., , –, , filename specifies file or list of files to display,, if file name is not specified all the files in the, directory will be listed., , –, , [/P] [/W] ......... specifies the switches for, formatting the output., , Switch, /P, , Pauses after each screenful of information and, waits to press any key. On pressing any key, another screenful or remaining information will, be displayed. Command is DIR/P, , /W, , Uses wide format of 80-column to display file, names only and information about file size,, date, and time is not displayed. Command is, DIR/W, , /A, , Displays files with specified attributes., , Uses lowercase., , / C[H] Displays file compression ratio; /CH uses host, allocation unit size., Important Notes:, – In the directory listing similar files can be listed by, using wildcards (* and ?), where (*) star and (?), question mark are called wild characters or wild cards., * can replace remaining charecters and ? can replace, any single character., – When DIR is used without parameters or switches, It, displays the disks volume label and serial number;, one directory or filename per line, including the file, size in bytes, and the date and time the file was, modified; and the total number of files listed, their, cumulative size and the free space ( in bytes), remaining on the disk., Examples, DIR *.txt, *.txt instruction will list all files having txt extension, in the specified directory., DIR ???T.*, ???T instruction will search for files having four, characters which ends with T like TEST,, REST etc. And * instructs that these files may have, any extension like .txt, .dat etc., , attribs, D Directories, R Read-only files, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished, , 55
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IT & ITES, Related Theory for Exercise 1.5.22, COPA - Dos & Linux operating systems, Methods to display the contents of a text file, Objectives: At the end of this lesson you shall be able to, • use DOS commands to display the contents of a text file, • use DOS commands to copy,rename,delete and undelete files., DOS Commands, , Examples, , TYPE Displays the contents of a text file., , 1 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt, , Syntax, , C:\COPA\DOS\PRACT_3 is the path to the file, TEST.txt and TYPE is the command to be executed, by DOS., , TYPE C:path/filename, Where,, –, , C: is the disk drive holding the file for displaying., , –, , path/ Specifies the location of file for displaying., , –, , filename specifies file to display., , Switch, , 2 C:\>TYPE C:\COPA\DOS\PRACT_3\>TEST1.txt, This results in the same output as in example1. While, working from C: (C drive) this command can be, issued with out changing the directories., 3 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt | MORE, This will also result in the same output but displayed, screen page by screen page. Screen page can be, changed on press of any key. Along with MORE, another character is prefixed ‘|’ this called the piping, command, Which will route the output of TYPE, command to another command MORE and the, MORE filter outputs the information., , (none), Important notes:, – TYPE command provides a quick way to display, contents of an ASCII file with out having to use, another program. The file is stored on the disk as, ASCII (American Standard code for Information, Interchange) text. which is standard way the computer, translates binary ( ones and zeros) into letters,, numbers & symbols. If the information is not stored in, the ASCII format, on using TYPE command the, information will look like gibberish., – On issuing command DOS will look in drive specified,, moves into the path to reach the filename specified., Then it simply translates ASCII format into the, characters, numbers and symbols and displays on, the monitor. The video monitor can show 24 lines of, information only. if the file contains more than 24, lines starting lines can not be seen since the type, command simply scrolls all information on to the, screen. Scrolling can be controlled by pressing, Control + S keys together (on holding control key, press S key and release both the keys is called as, Control + S) scrolling of information will stop on the, monitor. After viewing the contents on the screen any, key can be pressed to scroll through the remaining, contents. To view the contents of the file screen page, by screen page, MORE command can also be used., which will stop the scrolling of information on the, screen exactly after a screen page and in the screen, page at 24 line a prompt message — More— is, displayed. After pressing any key another screen, page will be displayed. MORE is a filter e.g. itis a, program that manipulates the stream of standard, characters to the file to the standard output (monitor), screen page by screen page., , 56, , Renaming of file(s), RENAME, Or, , This command allows to change, the name of a file., , REN, Syntax, REN C: PATH\filename1.ex1 filename2.ex2, Where,, – C: is the disk drive holding the file for displaying., – PATH/ Specifies the location of file for displaying., – filename1.ex1 is the file to be renamed, – filename2.ex2 is the new filename, Important Notes:, – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be renamed., – A valid file name with appropriate extension is to be, given for new filename., – Wild characters are permitted in the file names by, which required group of files can be renamed., , Copyright @ NIMI Not to be Republished
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– Only file names will be changed and contents remain, same., – If attempted to change a file name to a name that, already exists in the directory., DOS prompts an error message, , Instructor shall discuss the simple switches, with at least two examples in each case ., For further details on COPY command switches, refer any tutorial or hand book on DOS, Important Notes:, , Duplicate file name or file not found, – If a invalid file name or the new name is not given,, then also DOS prompts an error message, Rules for the file names., – A File name must have 1 to 8 characters., – An optional extension of 1 to 3 characters, – A period (.) between the name and extension name,, if extension is used, – All letters from A through Z ( lower case letters are, automatically transferred to uppercase), 0 to 9, numbers and special characters & symbols $ # & @, ! ^ ( ) _ - { } ‘ ~ are permitted in the file name., , – DOS command COPY can duplicate one or more, files. In the same directory with different names or, from one directory to other directory either in the, same name or in different name., – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used., – Exact file name with extension is to be given for the, file to be copied, – A valid file name with appropriate extension is to be, given for new copied filename, , – The control characters such as Esc, Del, or space bar, cannot be used in the file name., , – Wild characters are permitted in the file names by, which required group of files can be copied, , – The characters + = / [ ] : ; ? * < > : are not permitted., , – On copying, both source and target files will have, same contents., , – Each file name in a directory must be unique., Examples:, , – Copy overwrites the target file with the same name, , TEST2.txt, , – Copy will not allow to copy a file to it self that is source, and target files should not be same, , C:\COPA\DOS\PRACT_3\ is the drive and path to the, TEST2.txt file, TEST2.txt is the file name to be renamed, , – If the destination file name is not specified while, concatenation the first file name will become the, destination name. After the first file name, additional, source files must be preceded by a plus (+) sign., , CHECKED.txt is the new filename, , Example, , 1 C:\COPA\DOS\PRACT_3\>REN, CHECKED.txt, , 2 C:\COPA\DOS\PRACT_3\>REN *.pic *.jpg the pic, extension will be changed to jpg extension files., Copying files:, COPY Copies one or more files to another location., Syntax, COPY [/A | /B] source [/A | /B] [+ source [/A | /B] [+ ...]], [destination[/A | /B]] [/V] [/Y | /-Y] source specifies the file, or files to be copied. Destination specifies the directory, and/or filename for the new file(s)., Switches, /A, , Indicates an ASCII text file., , /B, , Indicates a binary file., , /V, , Verifies that new files are written correctly., , /Y, , Suppresses prompting to confirm you want to, overwrite an existing destination file., , /-Y Causes prompting to confirm you want to overwrite, an existing destination file., , 1 C:\COPA\DOS\PRACT_3\>COPY, TRIAL.txt, , TEST2.txt, , With the above command C:\COPA\DOS\PRACT_3, directory TEST2.txt file will be copied as TRIAL.txt, file in the same directory. On listing the directory both, the files will have same details and on viewing the, contents of both the file will be same. After copying, DOS prompts a message 1 file copied, 2 C:\COPA\DOS\PRACT_3\>COPY *.bmp *.pic, With the above command C:\COPA\DOS\PRACT_3, directory all files with bmp extension file will be, copied as pic extension files in the same directory., While copying DOS prompts the name of file it has, copied and after completion of copying it prompts the, number of files copied., 3 C:\COPA\DOS\PRACT_3\>COPY, C:\COPA\DOS\PRACT_4\, , *.pic, , All files with pic extension in C:\COPA\DOS\PRACT_3, directory will be copied to C:\COPA\DOS\PRACT_4, directory with same name & extension., Using *.* after the copy command will copy all files, with all extension to the destination., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 57
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Copy concatenating: Multiple file can be combined to, form a single file by use of + between the source files and, is called, as concatenation, Example 4 C:\COPA\DOS\PRACT_3\ COPY TEST2.txt, + TRIAL.txt CONCAT1.txt, With the above command TEST2.txt and TRIAL.txt will, be combined and CONCAT1.txt file will be created which, will have the contents of first two source files., Deleting file, DEL, , Deletes the files specified., , or, Erase, Syntax, DEL C:path/filename [/P], ERASE C:path/filename [/P], Where,, –, , C: is the disk drive holding the file to be deleted., , –, , path/ Specifies the location of file to be deleted., , –, , filename is the file to be deleted, , Switch, /P Prompts for confirmation before deleting the specified, file. Using the /P switch, If the /P switch is used, DEL displays the name of a file, and prompts with a message in the following format:, filename, Delete (Y/N)?, Press Y to confirm the deletion, N to cancel the deletion, and display the next filename (if a group of files are, specified), or CRTL+C to stop the DEL command., Important Notes, – If the drive is not specified current disk drive will be, used, – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be deleted, , The following command is given for deleting all the files., del *.*, DEL displays the following prompt:, All files in directory will be deleted! Are you sure (Y/N)?, Press Y and then ENTER to delete all files in the, current directory, or, press N and then ENTER to cancel the deletion., –, , Directories can not be removed with DEL command, a separate command is available for removing the, directory., , – Once the file is deleted it can not be recovered if the, memory space is occupied by a new file. If accidentally, file (s) are deleted immediately it can be recovered, by using utility command., – The space occupied by the deleted file on the disk or, diskette is freed., – Check for the typographic errors in the file names, before the press of enter key to activate delete, command, Example, 1 C:\COPA\DOS\PRACT_3\>DEL TEST2.txt, With the above command TEST2.txt file will be, deleted from the C:\COPA\DOS\PRACT_3 directory., On listing the directory TEST2,txt will not be available., 2 C:\COPA\DOS\PRACT_4\>DEL *.txt, With, the, above, command, in, the, C:\COPA\DOS\PRACT_4 directory all files with txt, extension will be deleted., 3 C:\COPA\DOS\PRACT_3\TEMP \> DEL *.*, All files with any extension in, C:\COPA\DOS\, PRACT_3\TEMP directory will be deleted., Recovering deleted files:, UNDELETE, , delete protection facility, , Syntax, UNDELETE C:path/filename [/DT | /DS | /DOS], , – Wild characters are permitted in the file names by, which required group of files can be deleted, , UNDELETE [/LIST | /ALL | /PURGE[DRIVE] | /, STATUS | /LOAD | /UNLOAD, , – On deleting, files name(s) will be removed from the, directory., , /UNLOAD | /S[DRIVE] | /T[DRIVE]-entrys ]], , – All the files in a directory can be deleted by typing the, DEL command followed by [drive:]path. Wildcard, also can be used (* and ?) to delete more than one file, at a time. However, Wildcards should be used, cautiously with the DEL command to avoid deleting, files unintentionally., , 58, , Where,, –, C: is the disk drive holding the files to be, undeleted., –, , path/ Specifies the location of file to be undeleted., , –, , filename is the file to be undeleted, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished
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Important Notes:, , Switches, /LIST, , Lists the deleted files available to be, recovered., , /ALL, , Recovers files without prompting for, confirmation., , /DOS, , Recovers files listed as deleted by, MS-DOS., , /DT, , Recovers files protected by Delete, Tracker., , /DS, , Recovers files protected by Delete, Sentry., , /LOAD, , Loads Undelete into memory for, delete protection., , /UNLOAD, , Unloads Undelete from memory., , /PURGE[drive], , Purges all files in the Delete Sentry, directory., , /STATUS, , Display the protection method in, effect for each drive., , /S[drive], , Enables Delete Sentry method of, protection., , /T[drive][-entrys], , Enables Delete Tracking method of, protection., , Once a file is deleted from disk, it may not be possible, to retrieve it. Although the UNDELETE command can, retrieve deleted files, it can do so with certainty only if, no other files have been created or changed on the disk., If a file is accidentally deleted and it is required to, keep, stop what all other activities on the computer and, immediately use the UNDELETE command to retrieve, the file., Example, 1 C:\COPA\DOS\PRACT_3\>UNDELETE TEST2.txt, With the above command TEST2.txt file will be, recovered. On listing TEST2.txt file will be available, in C:\COPA\DOS\PRACT_3 directory., 2 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE, With the above command multiple files can be, recovered. DOS will prompt for confirmation of, undeletion of each file and asks to type the first letter, of the file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen ., 3 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE /ALL, With the above command multiple files can be, recovered. DOS will not prompt for confirmation of, undeletion of each file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 59
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IT & ITES, COPA - Dos & Linux Operating System, , Related Theory for Exercise 1.5.23, , Introduction to Linux operating system, Objectives: At the end of this lesson you shall be able to, • overview of linux, • define futures of linux, • explain application area of linux, • describe about kernel., Overview of Linux, , Where is Linux?, , The operating system, , One of the most noted properties of Linux is where it can, be used. Windows and OS X are predominantly found on, personal computing devices such as desktop and laptop, computers. Other operating systems, such as Symbian,, are found on small devices such as phones and PDAs,, while mainframes and supercomputers found in major, academic and corporate labs use specialized operating, systems such as AS/400 and the Cray OS., , Developers need special tools (like the compilers and, command lines found in GNU) to write applications that, can talk to the kernel. They also need tools and applications, to make it easy for outside applications to access the, kernel after the application is written and installed., This collective set of tools, combined with a kernel, is, known as the operating system. It is generally the lowest, layer of the computer's software that is accessible by the, average user. General users get to the operating system, when they access the command line., Linux provides powerful tools with which to write their, applications: developer environments, editors, and, compilers are designed to take a developer's code and, convert it to something that can access the kernel and, get tasks done., Like the kernel, the Linux operating system is also, modular. Developers can pick and choose the operating, tools to provide users and developers with a new flavor of, Linux designed to meet specific tasks., Introduction to Linux, Linux (pronounced Lih-nucks) is a UNIX-like operating, system that runs on many different computers. Although, many people might refer to Linux as the operating, system and included software, strictly speaking, Linux is, the operating system kernel, which comes with a, distribution of software., Linux was first released in 1991 by its author Linus Torvalds, at the University of Helsinki. Since then it has grown, tremendously in popularity as programmers around the, world embraced his project of building a free, operating system, adding features, and fixing problems., Linux is popular with today's generation of computer, users for the same reasons early versions of the UNIX, operating system enticed fans more than 20 years ago., Linux is portable, which means you'll find versions, running on name-brand or clone PCs, Apple Macintoshes,, Sun workstations, or Digital Equipment Corporation, Alpha-based computers. Linux also comes with source, code, so you can change or customize the software to, adapt to your needs. Finally, Linux is a great operating, system, rich in features adopted from other versions of, UNIX., 60, , Linux, which began its existence as a server OS and Has, become useful as a desktop OS, can also be used on all, of these devices. ‚ÄúFrom wristwatches to, supercomputers,‚Äù is the popular description of Linux', capabilities., The future of Linux, Linux is already successful on many different kinds of, devices, but there are also many technological areas where, Linux is moving towards, even as desktop and server, development continues to grow faster than any other, operating system today., Linux is being installed on the system BIOS of laptop and, notebook computers, which will enable users to turn their, devices on in a matter of seconds, bringing up a, streamlined Linux environment. This environment will have, Internet connectivity tools such as a web browser and an, e-mail client, allowing users to work on the Internet without, having to boot all the way into their device's, primary operating system-even if that operating system is, Windows., At the same time, Linux is showing up on mobile Internet, devices (MIDs). This includes embedded devices such as, smart phones and PDAs, as well as netbook devicessmall laptop-type machines that feature the core, functionality of their larger counterparts in a smaller, more, energy-efficient package., The growth of cloud computing is a natural fit for Linux,, which already runs many of the Internet's web servers., Linux enables cloud services such as Amazon's A3 to, work with superior capability to deliver online applications, and information to users., Related to Linux' growth in cloud computing is the, well-known success of Linux on supercomputers, both in, the high-performance computing (HPC) and high-availability, (HA) areas, where academic research in physics and, bioengineering, and firms in the financial and energy, , Copyright @ NIMI Not to be Republished
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industries need reliable and scalable computing power to, accomplish their goals., Many of the popular Web 2.0 services on the Internet,, such as Twitter, Linked In, YouTube, and Google all rely, on Linux as their operating system. As new web services, arrive in the future, Linux will increasingly be the platform, that drives these new technologies., , The kernel of the Window operating system (which few, people outside of Microsoft are allowed to look at without, Fig 1, , Current application of Linux operating systems, Today Linux has joined the desktop market. Linux, developers concentrated on networking and services in, the beginning, and office applications have been the last, barrier to be taken down. They don't like to admit that, Microsoft is ruling this market, so plenty of alternatives, have been started over the last couple of years to make, Linux an acceptable choice as a workstation, providing an, easy user interface and MS compatible office applications, like word processors, spreadsheets, presentations and, the like. On the server side, Linux is well-known as a stable, and reliable platform, providing database and trading, services for companies like Amazon, the well-known online, bookshop, US Post Office, the German army and many, others. Especially Internet providers and Internet service, providers have grown fond of Linux as firewall, proxy- and, web server, and you will find a Linux box within reach of, every UNIX system administrator who appreciates a, comfortable management station. In post offices, they are, the nerve centres that route mail and in large search engine,, clusters are used to perform internet searches. These are, only a few of the thousands of heavy-duty jobs that Linux, is performing day-to-day across the world. It is also worth, to note that modern Linux not only runs on workstations,, mid- and high-end servers, but also on "gadgets" like PDA's,, mobiles, a shipload of embedded applications and even, on experimental wristwatches. This makes Linux the only, operating system in the world covering such a wide range, of hardware., The code, Linux is also unique from other operating systems in that, it has no single owner. Torvalds still manages the, development of the Linux kernel, but commercial and, private developers contribute other software to make the, whole Linux operating system., The kernel, All operating systems have kernels, built around the, architectural metaphor that there must be a central set of, instructions to direct device hardware, surrounded by, various modular layers of functionality. The Linux kernel is, unique and flexible because it is also modular in nature., Modularity is desirable because it allows developers to, shed parts of the kernel they don't need to use. Typically, a smaller kernel is a faster kernel, because it isn't running, processes it does not need., If a device developer wants a version of Linux to run on a, cell phone, she does not need the kernel functionality that, deals with disk drives, Ethernet devices, or big monitor, screens. She can pull out those pieces (and others), leaving, just the optimized kernel to use for the phone., , paying for the privilege) is a solidly connected piece of, code, unable to be easily broken up into pieces. It is difficult, (if not impossible) to pare down the Windows kernel to fit, on a phone., This modularity is significant to the success of Linux. The, ability to scale down (or up) to meet the needs of a specific, platform is a big advantage over other operating systems, constrained to just a few possible platforms., Modularity also effects stability and security as well. If, one piece of the kernel code happens to fail, the rest of, the kernel will not crash. Similarly, an illicit attack on one, part of the kernel (or the rest of the operating system), might hamper that part of the code, but should not, compromise the security of the whole device., The environments, The windows, menus, and dialog boxes most people think, of as part of the operating system are actually separate, layers, known as the windowing system and the desktop, environment., These layers provide the human-oriented graphical user, interface (GUI) that enables users to easily work with, applications in the operating system and third-party, applications to be installed on the operating system., In Linux, there a lot of choices for which windowing, system and desktop environment can be used,, something that Linux allows users to decide. This cannot, be done in Windows and it's difficult to do in OS X., Like the operating system and kernel, there are tools and, code libraries available that let application developers to, more readily work with these environments (e.g., gtk+ for, GNOME, Qt for KDE)., The applications, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished, , 61
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Operating systems have two kinds of applications: those, that are essential components of the operating system, itself, and those that users will install later. Closed, operating systems, like Windows and OS X, will not let, users (or developers) pick and choose the essential, component applications they can use. Windows, developers must use Microsoft's compiler, windowing, system, and so on., Linux application developers have a larger set of choices, to develop their application. This allows more flexibility to, build an application, but it does mean a developer will, need to decide which Linux components to use., The distributions, A Linux distribution is a collection of (usually open source), software on top of a Linux kernel. A distribution (or short,, distro) can bundle server software, system management, tools, documentation and many desktop applications in a, central secure software repository. A distro aims to, provide a common look and feel, secure and easy, software management and often a specific operational, purpose., Let's take a look at some popular distributions., Red hat, Red Hat is a billion dollar commercial Linux company that, puts a lot of effort in developing Linux. They have hundreds, of Linux specialists and are known for their excellent, support. They give their products (Red Hat, Enterprise Linux and Fedora) away for free. While Red, , 62, , Hat Enterprise Linux (RHEL) is well tested before release, and supported for up to seven years after release,, Fedora is a distro with faster updates but without, support., Ubuntu, Canonical started sending out free compact discs with, Ubuntu Linux in 2004 and quickly became popular for home, users (many switching from Microsoft Windows). Canonical, wants Ubuntu to be an easy to use graphical Linux desktop, without need to ever see a command line. Of course they, also want to make a profit by selling support for Ubuntu., Debian, There is no company behind Debian. Instead there are, thousands of well organised developers that elect a Debian, Project Leader every two years. Debian is seen as one of, the most stable Linux distributions. It is also the basis of, every release of Ubuntu. Debian comes in three versions:, stable, testing and unstable. Every Debian release is, named after a character in the movie Toy Story., Other, Distributions like Cent OS, Oracle Enterprise Linux and, Scientific Linux are based on Red Hat Enterprise Linux, and share many of the same principles, directories and, system administration techniques. Linux Mint, Edubuntu, and many other ubuntu named distributions are based on, Ubuntu and thus share a lot with Debian. There are, hundreds of other Linux distributions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.24 - 1.5.26, COPA - Dos & Linux Operating System, Handling commands and various editors, Objectives: At the end of this lesson you shall be able to, • know about terminal, • explain the command shell, • list out the directory layout of linux, • define the linux commands, • list out the special characters of linux OS, • explain various editors in linux OS., Starting up a terminal, , Some of the most popular shells are:, , To access the shell we will use a shell-like application,, also called a terminal emulator. There is a huge number, of good terminal applications out there, including the, default ones in GNOME or KDE, or Yakuake, Guake, rxvt, and so on. For now let's just stick with the default that, , • bash - the Bourne-Again Shell, the default shell on, most Linux systems., , • sh - the Bourne Shell, an older shell which is not so, widely used anymore., , Fig 1, , comes with your system. If you're using GNOME you can, access the terminal by going to Applications ->, Accessories -> Terminal or pressing Alt+F2 and typing, gnome-terminal in the run box that appears, followed by, Enter. If you're running KDE you can type instead, console after pressing Alt+F2., Depending on the distribution, the prompt may look something like user@host$. The first part before the ampersand is the login username, and the other one is the, hostname of the computer., Command shell, , • csh - the ‘C’ Shell, which accepts a syntax which, resembles the ‘C’ programming language., , • tcsh - an improved version of the ‘C’ Shell., • ksh - the Korn Shell, initially developed in the early, 1980’s., , • dash - Debian Almquist Shell, a shell created by the, Debian distribution., , Listing of shells available in the system, $ cat /etc/shells/, , A shell is a command interpreter which allows you to, interact with the computer. The way things work is pretty, simple: you type in commands, the shell interprets them,, performs the tasks it was asked to do, and finally it sends, the results to the standard output, which is usually the, screen., This is a list of files inside the root directory. The root, directory is the first location in the file system tree, hierarchy, and it is represented by the slash, character : /., , The above command will display the following output as, on Fig 2., In this tutorial we will focus on Bash, since it is the most, widely used and also one of the most powerful shells out, there. Bash is a modern implementation of the older, Bourne Shell (sh), developed by the GNU project, which, provides a huge amount of tools and which, together with, the Linux kernel, desktop environments like GNOME or, KDE and applications which run on top of them, comprise the whole Linux platform. On a Debian or Ubuntu, distribution, the default shell used by the system is specified in the file /etc/passwd (default being Bash)., 63, , Copyright @ NIMI Not to be Republished
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Fig 2, , How to display default shell in the system, Type the following command in the terminal, $ echo $SHELL, , And press Enter key. The default shell will be displayed, as on Fig 3., , Fig 3, , 64, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The Linux directory layout, Directory, , /bin, /boot, /dev, /etc, /home, /lib, /proc, /root, /sbin, /tmp, /usr, /usr/bin, /usr/include, /usr/lib, /usr/local, , /usr/sbin, /usr/share, /usr/src, /usr/X11R6, /var, , Description, The nameless base of the file system. All other directories, files, drives,, and devices are attached to this root. Commonly (but incorrectly), referred to as the “slash” or “/” directory. The “/” is just a directory, separator, not a directory itself., Essential command binaries (programs) are stored here (bash, ls,, mount, tar, etc.), Static files of the boot loader, Device files. In Linux, hardware devices are accessed just like other, files, and they are kept under this directory., Host-specific system configuration files., Location of users' personal home directories (e.g. /home/Susan)., Essential shared libraries and kernel modules., Process information pseudo-file system. An interface to kernel data, structures, The root (super user) home directory., Essential system binaries (fdisk, fsck, init, etc)., Temporary files. All users have permission to place temporary files here., The base directory for most shareable, read-only data (programs,, libraries, documentation, and much more)., Most user programs are kept here (cc, find, du, etc.)., Header files for compiling C programs., Libraries for most binary programs, “Locally” installed files. This directory only really matters in, environments where files are stored on the network. Locally-installed, files go in /usr/local/bin, /usr/local/lib, etc.). Also often used for, Software packages installed from source, or software not officially, shipped with the distribution., Non-vital system binaries (lpd, useradd, etc.), Architecture-independent data (icons, backgrounds, documentation,, terminfo, man pages, etc.)., Program source code. E.g. The Linux Kernel, source RPMs, etc., The X Window System, Variable data: mail and printer spools, log files, lock files, etc., , What are Linux commands?, Linux commands are executable binary files which can, be ran to perform certain tasks, like for example listing, the files in a directory running an entire graphical application. Examples of frequently used commands are ls,, cd, pwd, date or cat. With the exception of executable, files, there is also a category called shell built-ins, which, are commands provided by the shell itself (Bash in our, case). We'll deal with those later., The general form of a Linux command is:, command options(s) filename(s), Which specifies a command, followed by one or more, parameters, and optionally one or more files to apply it, on. For example:, $ echo -e 'Hello, world!\n', , Will output the text 'Hello, world!' followed by a newline, character. The -e parameter (also called argument, or, switch in this case) tells the echo command to interpret, escaped characters, like the trailing \n, which will add a, newline after the text inside the single quotes. Ignore the, leading dollar sign, it just signifies the shell prompt., A command may or may not have arguments. An argument can be an option or a filename., Special characters in linux operating system, it is important to know that there are many symbols and, characters that the shell interprets in special ways. This, means that certain typed characters: a) cannot be used, in certain situations, b) may be used to perform special, operations, or, c) must be "escaped" if you want to use, them in a normal way., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 65
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Character, , \, , Escape character. If you want to reference a special character, you must, “escape” it with a backslash first., Example: touch /tmp/filename\*, , /, , Directory separator, used to separate a string of directory names., Example: /usr/src/linux, , ., , Current directory. Can also “hide” files when it is the first character in a, filename., , .., , Parent directory, , ~, , User's home directory, , *, , Represents 0 or more characters in a filename, or by itself, all files in a, directory., Example: pic*2002 can represent the files pic2002, picJanuary2002,, picFeb292002, etc., , ?, , Represents a single character in a filename., Example: hello?.txt can represent hello1.txt, helloz.txt, but not, hello22.txt, , [], , Can be used to represent a range of values, e.g. [0-9], [A-Z], etc., Example: hello[0-2].txt represents the names hello0.txt,, hello1.txt, and hello2.txt, , |, , “Pipe”. Redirect the output of one command into another command., Example: ls | more, , >, , Redirect output of a command into a new file. If the file already exists,, over-write it., Example: ls > myfiles.txt, , >>, , 66, , Description, , Redirect the output of a command onto the end of an existing file., Example: echo .Mary 555-1234. >> phonenumbers.txt, , <, , Redirect a file as input to a program., Example: more < phonenumbers.txt, , ;, , Command separator. Allows you to execute multiple commands on a single, line., Example: cd /var/log ; less messages, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The cd command, The cd command is used to change the current directory, (i.e., the directory in which the user is currently working), in Linux and other Unix-like operating systems. It is similar, to the CD and CHDIR commands in MS-DOS., cd's syntax is, cd [option] [directory], The items in square brackets are optional. When used, without specifying any directory name, cd returns the user, to the previous current directory. This provides a convenient, means of toggling between two directories., When a directory name is provided, cd changes the current, directory to it. The name can be expressed as an absolute, pathname (i.e., location relative to theroot directory) or as, a local pathname (i.e., location relative to the current, directory). It is usually more convenient to use a local, pathname when changing to a subdirectory of the current, directory., As an example, the following would change the current, directory, regardless of where it is on the system (because, it is an absolute path), to the root directory (which is, represented by a forward slash):, cd /, Likewise, the following would change the current directory,, regardless of its location, to the /usr/sbin directory (which, contains non-vital system utilities that are used by the, system administrator):, cd /usr/sbin, If a user currently in the directory /usr/local/share/man/, desired to change to the directory /usr/local/share/man/, man2, which is a subdirectory of the current directory, it, would be possible to change by using the absolute, pathname, i.e.,, cd /usr/local/share/man/man2, However, it would clearly be much less tedious to use the, relative pathname, i.e.,, cd man2, On Unix-like operating systems the current directory is, represented by a singledot and its parent directory (i.e.,, the directory that contains it) is represented by two, consecutive dots. Thus, it is possible (and often convenient), to change to the parent of the current directory by using, the following:, cd .., Another convenient feature of cd is the ability for any user, to return directly to its home directory by merely using a, tilde as the argument. A home directory, also called a, login directory, is the directory on a Unix-like operating, system that serves as the repository for a user's personal, files, directories and programs. It is also the directory that, a user is first in after logging into the system. A tilde is a, short, wavy, horizontal line character that represents the, , home directory of the current user. That is, any user can, return immediately to its home directory by typing the, following and then pressing the Enter key:, cd ~, This is easier than typing the full name of the user's home, directory, for instance, /home/josephine in the case of a, user named josephine. (And it is just one of the numerous, shortcuts that help make the command line on Unix-like, operating systems so easy to use.), When followed by a space and then a hyphen, cd both, returns the user to the previous current directory and, reports on a new line the absolute pathname of that, directory. This can further enhance the already convenient, toggling capability of cd. Toggling is particularly convenient, when at least one of the two directories has a long absolute, pathname, such as /usr/local/share/man/man2., cd has only two options, and neither of them are, commonly used. The -P option instructs cd to use the, physical directory structure instead of following symbolic, links. The -L option forces symbolic links to be followed., The pwd command, The pwd command reports the full path to the current, directory., The current directory is the directory in which a user is, currently operating while using a command line interface., A command line interface is an all-text display mode and, it is provided via a console (i.e., a display mode in which, the entire screen is text only) or via a terminal window, (i.e., a text-only window in a GUI)., The full path, also called an absolute path, to a directory, or file is the complete hierarchy of directories from the, root directory to and including that directory or file. The, root directory, which is designated by a forward slash (/),, is the base directory on the filesystem (i.e., hierarchy of, directories), and it contains all other directories,, subdirectories and files on the system. Thus, the full path, for any directory or file always begins with a forward slash., pwd is one of the most basic commands in Linux and, other Unix-like operating systems, along with ls, which is, used to list the contents of the current directory, andcd,, which is used to change the current directory., pwd's syntax is, pwd [option], Unlike most commands, pwd is almost always used just, by itself, i.e.,, Pwd, That is, it is rarely used with its options and never used, with arguments (i.e., file names or other information, provided as inputs). Anything that is typed on the same, line after pwd, with the exception of an option, is ignored,, and no error messages are returned., As an example, if a user with the username janis is in its, home directory, then the above command would typically, return /home/janis/ (because, by default, all home, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 67
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directories are located in the directory /home). Likewise,, if a user were currently working in directory /usr/share/, config (which contains a number of programconfiguration, files), then the same command would return /usr/share/, config., pwd is useful for confirming that the current directory has, actually been changed to what the user intended after, using cd. For example, after issuing the cd command to, change the current directory from /home/janis to /usr/share/, config, pwd could be used for confirmation; that is, the, following sequence of commands would be issued:, cd /usr/share/config/, pwd, The standard version of pwd has a mere two options, both, of which are employed only infrequently. The --help option, is used as follows:, pwd --help, This option displays information about pwd, of which there, is very little because it is such a simple command (i.e., it, only has two options and accepts no arguments)., The other option is --version, which displays the version, number, i.e.,, pwd --version, Although it is often thought of as standing for present, working directory, pwd is actually an acronym for print, working directory. The word print is traditional, UNIXterminology for write or display, and it originated when, computer output was typically printed on paper by default, because CRT (cathode ray tube) display monitors were, not yet widely available., The echo command, echo is a built-in command in the bash and C shells that, writes its arguments to standard output., A shell is a program that provides the command line (i.e.,, the all-text display user interface) on Linux and other Unixlike operating systems. It also executes (i.e., runs), commands that are typed into it and displays the results., bash is the default shell on Linux., A command is an instruction telling a computer to do, something. An argument is input data for a command., Standard output is the display screen by default, but it, can be redirected to a file, printer, etc., The syntax for echo is, $ echo $USER, $ echo "Hello world", The items in square brackets are optional. A string is any, finite sequence of characters (i.e., letters, numerals,, symbols and punctuation marks)., When used without any options or strings, echo returns a, blank line on the display screen followed by the command, prompt on the subsequent line. This is because pressing, the ENTER key is a signal to the system to start a new, 68, , line, and thus echo repeats this signal., When one or more strings are provided as arguments,, echo by default repeats those stings on the screen. Thus,, for example, typing in the following and pressing the ENTER, key would cause echo to repeat the phrase This is a pen., on the screen:, echo This is a pen., It is not necessary to surround the strings with quotes, as, it does not affect what is written on the screen. If quotes, (either single or double) are used, they are not repeated, on the screen., Fortunately, echo can do more than merely repeat verbatim, what follows it. That is, it can also show the value of a, particular variable if the name of the variable is preceded, directly (i.e., with no intervening spaces) by the dollar, character ($), which tells the shell to substitute the value, of the variable for its name., For example, a variable named x can be created and its, value set to 5 with the following command:, x=5, The value of x can subsequently be recalled by the following:, echo The number is $x., Echo is particularly useful for showing the values of, environmental variables, which tell the shell how to behave, as a user works at the command line or in scripts(short, programs)., For example, to see the value of HOME, the environmental, value that shows the current user's home directory, the, following would be used:, echo $HOME, Likewise, echo can be used to show a user's PATH, environmental variable, which contains a colon-separated, list of the directories that the system searches to find the, executable program corresponding to a command issued, by the user:, echo $PATH, echo, by default, follows any output with a newline, character. This is a non-printing (i.e., invisible) character, that represents the end of one line of text and the start of, the next. It is represented by \n in Unix-like operating, systems. The result is that the subsequent command, prompt begins on a new line rather than on the same line, as the output returned by echo., The -e option is used to enable echo's interpretation of, additional instances of the newline character as well as, the interpretation of other special characters, such as a, horizontal tab, which is represented by \t. Thus, for, example, the following would produce a formatted output:, echo -e "\n Projects: \n\n\tplan \n\tcode \n\ttest\n", (The above command should be written on a single line,, although it may render as two lines on smaller display, screens.) The -n option can be used to stop echo from, adding the newline to output., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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By making use of output redirection, echo provides a very, simple way of creating a new file that contains text. This, is accomplished by typing echo followed by the desired, text, the output redirection operator (which is a rightward, pointing angle bracket) and finally the name of the new, file. The file can likewise be formatted by using special, characters. Thus, for example, the formatted output from, the above example could be used to create a new file, called project1:, , Date command, , echo -e "\n Project1: \n\n\tplan \n\twrite \n\ttest\n" >, project1, , 01:13:14, , The contents of the new file, including any formatting, can, be verified by using a command such as cat or less, i.e.,, , Display current time and date., $ date, Fri Jul 6 01:07:09 IST 2012, If you are interested only in time, you can use 'date +%T', (in hh:mm:ss):, $ date +%T, tty command, Displays current terminal., $ tty, , less project1, echo can likewise be a convenient way of appending text, to the end of a file by using it together with the the append, operator, which is represented by two consecutive rightward, pointing angle brackets. However, there is always the risk, of accidentally using a single bracket instead of two,, thereby overwriting all of the contents of the file, and thus,, this feature is best reserved for use in scripts., echo can also be used with pattern matching, such as the, wildcard character, which is represented by the star, character. For example, the following would return the, phrase The gif files are followed by the names of all the .gif, image files in the current directory:, echo -e The gif files are *.gif, , /dev/pts/0, whoami command, This command reveals the current logged in user., $ whoami, raghu, id command, This command prints user and groups (UID and GID) of, current user., $ id, uid=1000(raghu) gid=1000(raghu), groups = 1000 (raghu), 4(adm), 20(dialout), 24(cdrom),, 46(plugdev), 112(lpadmin), 120(admin),122(sambashare), , The cal command, Displays calendar of current month., , By default information about current user is displayed. If, another username is provided as an argument, information, about that user will be printed:, , $ cal, July 2012, , $ id root, , Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , Clear command, , 15, , 16, , 17, , 18, , 19, , 20, , 21, , This command clears the screen., , 22, , 23, , 24, , 25, , 26, , 27, , 28, , Getting help command, , 29, , 30, , 31, , 'cal ' will display calendar for specified month and year., $ cal 08 1991, August 1991, Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , uid=0(root) gid=0(root) groups=0(root), , For all its advantages, a big disadvantage of command, line is that there are a lot of commands and even more are, their options and usage. But nobody can remember all, commands. There are some smarter ways of using, command line. Linux provides us with several such, resources discussed here:, --help option, With almost every command, '--help' option shows usage, summary for that command., , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , 15, , 16, , 17, , $ date --help, , 18, , 19, , 20, , 21, , 22, , 23, , 24, , Usage: date [OPTION]... [+FORMAT], , 25, , 26, , 27, , 28, , 29, , 30, , 31, , or: date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]], Display the current time in the given FORMAT, or set the, system date., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 69
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The whatis command, , $ info date, , The whatis command provides very brief descriptions of, command line programs (i.e., all-text mode programs) and, other topics related to Linux and other Unix-like operating, systems., It accomplishes this by searching the short descriptions, in the whatis database for each keyword provided to it as, an argument (i.e., input data). This database contains just, the title, section number and description from the NAME, section of each page in the man manual that is built into, most Unix-like systems., The syntax for whatis is:, whatis keyword(s), For example, the following provides a single line summary, of the headcommand (which by default displays the first, ten lines of each file that is provided to it as an argument):, whatis head, whatis can be used to simultaneously search for information, about multiple topics. For example, the following would, provide information about both head and tail (which by, default reads the final ten lines of files):, whatis head tail, The output of whatis is limited by the fact that it provides, only a single line for each keyword found in the database;, thus it supplies incomplete information about even, moderately complex commands. For example, the, following use of whatis to obtain information about the cat, command generates the output "concatenate files and print, on the standard output":, whatis cat, However, this omits some important information about cat,, particularly the facts that it is very convenient to use for, reading files and that it is also used to create and write to, files., whatis is similar to the apropos command. However,, apropos is more powerful in that its arguments are not, limited to complete words but can also be strings (i.e.,, any finite sequences of characters) which comprise parts, of words. Both commands are unusual in that they have, no options., The man command (which is used to read the built-in, manual pages), when used with its -f option, produces the, same output as whatis. Thus, for example,, man -f cat, is equivalent to, whatis cat, Info pages, , Word processors in the Linux environment, Text editors are used by many different types of people., Casual users, writers, programmers, and system, administrators will all use a text editor at one time or another, in Linux., Use of text editor, A text editor is just like a word processor without a lot of, features. All operating systems come with a basic text, editor. Linux comes with several. The main use of a text, editor is for writing something in plain text with no formatting, so that another program can read it. Based on the, information it gets from that file, the program will run one, way or another., vi Editor, "vi" (pronounced "vee eye") is a text editor with a, deceptively simple appearance that belies its great power, and efficiency. New users soon realize that there is far, more to this little program than meets the eye., vi, or one of its clones, is found in almost every version of, Linux and Unix, and, in fact, it is the only editor that is, available in virtually every Unix installation., History of vi, The vi editor was developed starting around 1976 by Bill, Joy, who was then a graduate student at the University of, California at Berkeley. Joy later went on to help found Sun, Microsystems and became its Chief Scientist., "ed" was the original Unix text editor. Like other early text, editors, it was line oriented and used from dumb printing, terminals. Joy first developed "ex" as an improved line, editor that supported a superset of ed commands. He then, developed vi as a "visual interface" to ex. That is, it allows, text to be viewed on a full screen rather than only one line, at a time. vi takes its name from this fact., vi remains very popular today in spite of the development, and widespread availability of GUI (graphical user interface), mode text editors which are far more intuitive and much, easier for beginners to use than text-mode text editors, such as vi. GUI-mode text editors include gedit and Emacs,, both, of, which, have, become, very, common on Linux and other Unixes today., Features of vi, , • It is present in almost every Linux Unix system, even, the most minimal., , • It is very small. In fact, some versions have a total, , code size of less than 100KB. This makes it easy to, include vi on even the tiniest versions of Linux, such as, those in embedded systems and those that run from a, single floppy disk., , Info documents are sometimes more elaborated than man, pages. But for some commands, info pages are just the, • It is typist-friendly, at least once you get used to it. For, same as man pages. These are like web pages. Internal, example, the commands are very short, usually just a, links are present within the info pages. These links are, few keystrokes. And because vi does not use the, called nodes. info pages can be navigated from one page, mouse, there is never any need to remove one's hands, to another through these nodes., 70, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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from the keyboard. This can speed up editing, substantially., , changes, hit ESC, type :q! and then press ENTER. This, is sometimes referred to as a "forced quit.", , • It is very powerful, as just a few very short commands, , vi works with a buffer (a block of memory in the RAM, chips). When you open an existing file, vi copies that file, from the hard disk (or floppy, CDROM, etc.) to a buffer. All, changes that you make to a file are initially made only to, the copy in the buffer, and they are only made to the file, itself when you "save" your changes. "Saving" a file means, writing (i.e., transferring) the contents of the buffer to the, hard disk (or floppy disk)., , can make sweeping changes to large documents. In, fact, vi is more powerful than most of its users realize,, and few of them know more than just fraction of all the, commands., , Opening and closing file, vi can be used both when your system is in text mode, (the entire screen is devoted to text and there are no, images) and when your system is in GUI mode (the screen, contains windows, images and menus). When it is in GUI, mode (usually KDE or Gnome), vi runs in a terminal window., A terminal window is a text-only window, and it can usually, be opened by clicking on an icon (small image) of a, computer screen., (In the case of Red Hat Linux, the terminal window can be, opened by clicking on the icon of a red hat in the lower left, hand corner of the screen, opening the System Tools menu, and then selecting Terminal from that menu. It can be, convenient to add the icon for the terminal window to the, launcher panel along the bottom of the screen, if it is not, already there.), There are at least two ways to use vi to simultaneously, create and open a new file. One is by just typing vi at the, command line, like this:, vi, This creates an empty file that will not have a name until, you save its contents to disk (i.e., transfer the text you, typed into it to your hard disk, floppy disk, etc. for long, term storage)., A second way to open a new file is by typing vi followed by, the name of the file to be created, for example:, vi apple, This creates a new file named "apple" in the current, directory (the directory or folder which is currently open, on your all-text screen or your terminal window)., If you want, it could create the same file with an extension, such as ".txt" added to the end of the file name. In Linux, this is merely a matter of convenience (or habit), and it, generally makes no real difference for the file because it, remains a plain text file in either case. For example:, vi apple.txt, To close a file to which no changes have been made, hit, ESC (the Esc key, which is located in the upper left hand, corner of the keyboard), then type :q (a colon followed by, a lower case "q") and finally press ENTER. (The term "hit", is used here instead of "press" to emphasize that it is not, necessary to keep the ESC key held down but just to, press it momentarily.), To close a file to which changes have been made (such as, text having been added or removed) without saving the, , Likewise when you open a new file. All text you enter (and, subsequent edits you make to it) exists only in the buffer, until you save the file to disk., To save the changes that have been made to a file, hit, ESC, type :qw and then press ENTER. The "w" stands for, "write." An alternative, and perhaps easier, way to save a, file and quit at the same time is to hit ESC and then type, ZZ (two capital Z's in succession)., After you have created a new text file and closed it, you, might want to confirm that nothing went wrong and that, the file actually exists. Probably the simplest way to do, this is to use the standard Unix ls command, which, displays a list of all of the files in the current directory., Entering text, vi has two basic modes of operation: command mode and, text insert mode. How to switch back and forth, between them is probably the most confusing thing about, vi for beginners. But it is actually very simple, and once, you get used to it you might also find it quite efficient., Command mode is the default mode when a file (existing, or new) is opened. (This is the opposite of most text and, word processors and therefore may seem counter-intuitive.), Because every file opens initially in command mode, you, can not immediately begin typing text. That is, everything, that is typed on the keyboard is interpreted by vi to be a, command., Examples of the many types of commands can perform, on a file while in command modes are:-, , • Switching to text insert mode., • Moving the cursor around the file., • Deleting characters or lines., • Transposing characters., • Changing case., • Appending the contents of the file to another (closed), file., , • Setting vi options., • Saving the file to disk., • Closing the file and quitting vi., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 71
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The other mode, text insert mode, is also referred to as, simply "insert mode" or "input mode." It is used for entering, text into the buffer memory (and simultaneously onto the, screen). In this mode everything that is typed on the, keyboard is added to the text and does not become a, command (although you can perform some command, operations in text mode with vi clones)., , There will be times when it need to place a character to, the right of the character under the cursor. This is, particularly useful when the cursor is over the last character, in a line and you want to append the line. To do this,, simply use the a (lower case "a," which stands for "append"), command instead of the i command to switch from, command mode into insert mode., , The most common way to switch from command mode to, the input mode is to use the i (which stands for "insert" or, "input") command. This is accomplished by simply typing, the letter i while in command mode. Now you are ready to, start typing text., , After it have saved a file that have created or modified, using vi, might want to verify that its contents are really, what you had intended. One way to do this is to use cat,, the Unix concatenation utility. (No, this has no relationship, to the popular domesticated animal whose name has the, same spelling). For example, type:, , Unlike word processors and even most word editors, there, is no automatic word wrap in the traditional version of vi, (although you will notice it in some clones). New lines are, started by pressing ENTER., When finished typing text or need to perform some other, operation such as moving to a different position in the text, or deleting some of it, hit ESC in order to return to the, command mode., Once you have typed some text, you can use the four, basic commands for moving the cursor around the text., These commands enable you to go to any desired location, in order to modify the text, including making insertions, and deletions. The four basic cursor positioning commands, are:, h move cursor one character to left, j move cursor one line down, k move cursor one line up, l move cursor one character to right, Each of these commands can be either used by itself or, modified by typing an integer in front of it to indicate the, number of characters or lines to move. For example, typing, (in command mode, of course), 3j - will move the cursor down three lines. Or typing 2h will, move it two characters to the left., These commands can be repeated by holding the key, down. If attempting an impossible movement, such as, pressing k when the cursor is on the top line, the screen, might flash or a beeping sound might be made (depending, on how your computer is set up)., The cursor can be moved directly to any desired line by, using the G command preceded by the line number. For, example, typing, 5G - moves the cursor to the fifth line from the top of the, text. Just typing G without any number moves the cursor, to the final line of text., When you switch from command mode to input mode, with the i command and then start typing text, each, character you type is placed to the left of the character, covered by the cursor. This causes the character covered, by the cursor as well as everything to its right to be shifted, to the right., 72, , cat /home/john/fruit/lemon, Editing Text, vi offers a rich assortment of commands for editing text., Among the most basic are those used for deleting or, erasing., The x (lower case "x") command deletes the character, immediately under (i,e., covered by) the cursor. To delete, any desired character, just switch to the command mode, (if you are not already there) and then use an appropriate, combination of the h, j, k and l commands (of course, one, at a time) to move the cursor to that character. Then type, x and the character is deleted., By pressing x continuously instead of just hitting it once,, the cursor continuously moves to the right and each, character under it is successively deleted., The X (upper case "X") command is similar except that it, deletes the character to the left of the cursor rather than, the character under it., There are several additional commands for deleting text., The D (upper case "D") command removes the text on the, current line from the character under the cursor to the end, of the line., The d (lower case "d") command is very flexible because, it can be modified to delete any number of characters,, words or lines. Typing d by itself will not do anything, but, typing dw causes the character the cursor is resting on, and the remaining characters to the right of it in the same, word to be deleted. (The "w" stands for "word."), Typing 2dw causes the character under the cursor, the, remaining characters to the right of it in the same word, and all of the characters in the next word to be deleted., For example, typing 2dw with the cursor on the "a" of the, string "pineapple plantation" causes the string "apple, plantation" to be deleted., As another example, typing 3dw with the cursor on the "j", of the string "the bluejay flew south" causes the string, "jay flew south" to be deleted. That is, "jay" and two words, to the right of it are deleted., Deleting an entire line can be accomplished with the dd, command. This command can also be used to delete, multiple lines by preceding it with an integer representing, the number of lines to be removed. For example, typing, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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2dd will delete two consecutive lines beginning with the, current line., , lines can be transposed with the ddp command by placing, the cursor on the upper line and typing ddp., , With some terminals, deletion of a line causes it to be, replaced on the screen with an "@" character. This, character merely represents an empty line and is not, inserted into the text. Its purpose is to relieve the processor, from having to redraw the screen (i.e., change the whole, screen). This character can be removed if desired by typing, r (or l on some terminals) while holding down the CTRL, key., , It is also a simple matter to change the case of a letter., When the cursor is over the desired letter, hit the "~" (tilde), key. This will change a capital letter to a small letter and, visa versa., , The change command c (lower case "c") differs from the, delete command in that it not only deletes a section of, text but also activates insert mode to allow you to type in, replacement text. After you have completed typing in the, replacement text, be sure to press ESC to return to the, command mode., As is the case with d, the c command is not used by itself, but is only used in combination with another letter after it, and an optional integer before it., For example, the command cw (which stands for "change, word") deletes the characters in the current word under, and to the right of the cursor and then switches vi to the, insert mode so that you can enter text to replace the deleted, characters. The number of new characters typed in can, be the same as, fewer or more than the number deleted., The amount of text to be changed can be increased by, preceding the command with a number. For instance, typing, 2cw will additionally remove the next word for replacement, with whatever is typed in. The space between the words is, not preserved., The d and c commands can also be modified by other, characters in addition to "w." For example they can be, used with "b," which stands for "back." Thus, typing3bd, will delete the characters to the left of the cursor in the, current word together with the two words to the left of the, current word., The cc command erases the current line, leaving it blank, and awaiting replacement text. Preceding this command, with an integer will delete that number of lines, beginning, with the current line. For example, typing 5cc will allow, you to change five consecutive lines starting with the current, line., Another change command, R, differs from the c commands, in that it does not initially delete anything. Rather, it, activates insert mode and lets you replace the characters, under the cursor one at a time with characters that you, type in., vi supports several types of transposition. Transposing the, order of two adjacent characters is easy with the xp, command. Just place the cursor on the left-most of the, two characters, type x to erase the left character and then, type p for the deleted character to be put to the right of the, cursor., Two adjacent words can be transposed with the deep, command. To use it, position the cursor in the space just, to the left of the word on the left and type deep. Two adjacent, , The J (upper case "J") command is used to join the next, line to the current line. The opposite operation, splitting a, line, is accomplished in insert mode by merely positioning, the cursor over what will be the first character of the new, line and then hitting ENTER., vi also has an undo capability. The u (lower case "u"), command is used to reverse the effects of an already issued, command that has changed the buffer, but which is not, yet written to disk. U (upper case "U") undoes all of the, changes that have been made to the current line during, your current visit to it, Searching Text, vi also has powerful search and replace capabilities. To, search the text of an open file for a specific string, (combination of characters or words), in the command, mode type a colon (:), "s," forward slash (/) and the search, string itself. What you type will appear on the bottom line, of the display screen. Finally, press ENTER, and the, matching area of the text will be highlighted, if it exists. If, the matching string is on an area of text that is not currently, displayed on the screen, the text will scroll to show that, area., The formal syntax for searching is:, :s/string, For example, suppose you want to search some text for, the string "cherry." Type the following and press ENTER:, :s/cherry, The first match for "cherry" in your text will then be, highlighted. To see if there are additional occurrences of, the same string in the text, type n, and the highlight will, switch to the next match, if one exists., The syntax for replacing one string with another string in, the current line is, :s/pattern/replace/, Here "pattern" represents the old string and "replace", represents the new string. For example, to replace each, occurrence of the word "lemon" in a line with "orange,", type:, :s/lemon/orange/, The syntax for replacing every occurrence of a string in, the entire text is similar. The only difference is the addition, of a "%" in front of the "s":, :%s/pattern/replace/, Thus repeating the previous example for the entire text, instead of just for a single line would be:, :%s/lemon/orange/, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 73
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Working with multiple files, It is easy to insert text into an open file from another file., All that is necessary is to move the cursor to the location, where you want the text inserted, then type, :r filename, where "filename" is the name of the file to insert., For example, if you want to copy the contents of the file, "peach" into the file "fruit," you would first position the, cursor to the desired line in "fruit" and then type, :r peach, Notice that this operation causes no change to the file, "peach.", , vi +3 apple, Use of the + command without any modifying number, opens a file with the cursor positioned on the last line of, text. This can save some keystrokes when you want to, open a file just to append data to the end of it. For example:, vi + apple, You have already learned several commands for switching, from command mode to insert mode, including i for, inserting to the left of the cursor position, a for inserting to, the right of the cursor position and the c commands for, changing text. A more complete list is as follows:, a, , appends after current cursor position., , A, , appends at end of current line., , c, , starts a change option., , C, , starts a change option from current position, to end of current line., , i, , inserts to the left of the cursor position., , I, , inserts at start of line., , o, , cursor moves to new, blank line below its, current position., , This allows you to edit "apple" first. After saving "apple,", typing :n calls up "pear" for editing., , O, , cursor moves to new, blank line above its, current position., , If you want to simultaneously open all files in the current, directory, just type vi * (vi + space + asterisk)., , R, , replaces characters one at a time., , Additional operations, , A simple way to obtain basic information about any file, that is currently open, including name, size and the current, line number, is to hold down CTRL and type g. This data, appears on the bottom line of the display., , You can also append text from the currently open file to, any other file. This is accomplished using the :w (colon +, "w") command followed without a space by >>. For, example, to append the contents of a currently open file, named "pear" to the file named "apple," type, :w>> apple, At times it can be convenient to open multiple files, simultaneously. This is efficiently accomplished by just, listing all of the files to be opened after the vi command., For example, to simultaneously open files about three kinds, of fruit, type:, vi apple pear orange, , As you have learned, creating and opening files in vi can, be a very simple matter. However, many combinations of, options are available that can add much power and, flexibility for these tasks, as can be seen by looking at, the full syntax for opening files:, vi [flags] [cmd] [filename], The square brackets ([ ]) around each section of arguments, (modifiers) of the command indicates that they are optional., (That is, a file can be opened by just typingvi alone or by, typing it with any combination of the three arguments. For, instance, the example of vi dog contains only the, mandatory vi and the optional third argument, which is the, name of the file to open.), , Summary of commands, The following list contains the basic commands presented, in the first eight pages of this tutorial along with occasional, examples of usage (shown in parenthesis). They are, presented in roughly the same order in which they appear, in the tutorial. (All commands that begin with a colon are, followed by ENTER.), , As only one of many possible examples of adding options, for opening files, an existing file can be opened with the, cursor appearing on any desired line instead of just on the, first line. (One situation in which this can be particularly, useful is if your file is part of a program which you are, writing and the compiler reports an error on a specific line, in that file.) This is accomplished by adding the + (plus, sign) command followed the desired line number. For, example, to open the file "apple" with the cursor located, on the third line, type:, 74, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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vi, vi *, , typed at the command line to open one or more files in the same directory, (vi tomato.txt opens a file named "tomato.txt" in the current directory), (vi parsley sage rosemary opens the three files "parsley," "sage" and, "rosemary" in the current directory), typed at the command line to open every file in the current directory, , :q, , closes (quits) a file to which no changes have been made, , :q!, , quits without saving any changes, , :w, , writes (i.e., saves) the current file to disk, , :wq, ZZ, i, h, , writes the buffer contents to disk (i.e., saves changes) and quits, same as :wq, activates text insert mode, inserting text immediately under the current, position of the cursor., moves the cursor one character to the left, (2h moves the cursor two characters to the left), , j, , moves the cursor one line down, (3j moves the cursor three lines down), , k, , moves the cursor one line up, , l, , moves the cursor one character to the right, , G, , moves the cursor to the desired line; moves the cursor to the last line of text, if not preceded by a modifying integer, (5G moves the cursor to the fifth line), , a, , switches to insert mode and allows insertion of text immediately to the right, of the cursor., , x, , deletes the character immediately under the cursor, (xxx deletes the character immediately under cursor and then deletes the, two characters to its right), , X, , deletes a single character to the left of cursor, , D, , removes the text on the current line from the character under the cursor to, the end of the line, , dw, , deletes the character immediately under the cursor and the remaining, characters to the right of it in the same word, (2dw deletes the character immediately under the cursor, the remaining, characters to the right of it in same word and all of the next word), , dd, , deletes the entire line containing the cursor, and the cursor then moves to, the next line, (2dd deletes two consecutive lines beginning with the current line), , cw, , deletes the character under the cursor and to its right in the same word and, allows new characters to be typed in to replace them, (2cw deletes the character under the cursor and to its right in the same, word and in the next word, and then allows replacement characters to be, typed in), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 75
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cc, , erases the current line and allows replacement text to be typed in, (2cc erases the current line and the next line and allows replacement text to, be typed in for both lines), , cb, , deletes the characters to the left of the cursor in the current word and allows, replacement characters to be typed in, (3cb deletes the characters to the left of the cursor in the current word, together with the two words to its left and then allows replacement text to be, typed in), , R, , activates text input mode allowing text under and to the right of the cursor to, be overwritten one character at a time, , xp, , transposes two adjacent characters, , deep, ddp, , transposes two adjacent lines, , ~, , changes case of the character under the cursor, , J, , joins the current line with the next line, , u, , reverses the effects of the most recent command that has changed the buffer, , U, , undoes all changes made to the current line during the current visit to it, , :s/, n, :s/ / /, , :%s/, //, , 76, , transposes two adjacent words, , searches the text for the first instance of a designated string, (:s/cucumber searches the text for the first instance of the string, "cucumber"), searches the text for the next instance of a designated string, replaces the first instance of a designated string, (:s/cucumber/radish/ replaces the first instance of the string "cucumber" with, the string "radish"), replaces every instance of a designated string, (:%s/cucumber/radish/ replaces every instance of the string "cucumber" with, the string "radish"), , :r, , inserts text into the currently open file from another file, (:r lettuce.txt inserts text into the currently open file from the file named, "lettuce.txt"), , :w>>, , appends the text from the currently open file into another file, (:w>> cabbage appends the text from the currently open file into the file, named "cabbage"), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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pico editor, , offered as the default in subsequent searches., , pico is a simple text editor in the style of the pine, composer., , Blocks of text can be moved, copied or deleted with, creative use of the command for mark (Ctrl-^), delete, (Ctrl-k) and undelete (Ctrl-u). The delete command will, remove text between the "mark" and the current cursor, position, and place it in the "cut" buffer. The undelete, command effects a "paste" at the current cursor, position., , Syntax, pico [ options ] [ file ], Description, pico is a simple, display-oriented text editor based on the, pine message composer. As with pine, commands are, displayed at the bottom of the screen, and context-sensitive, help is provided. As characters are typed they are, immediately inserted into the text., Editing commands are entered using control-key, combinations. As a work-around for communications, programs that swallow certain control characters, you can, emulate a control key by pressing ESCAPE twice, followed, by the desired control character. For example, "ESC ESC, c" would be equivalent to entering a ctrl-c. The editor has, five basic features: paragraph justification, searching, block, cut/paste, a spelling checker, and a file browser., Paragraph justification (or filling) takes place in the, paragraph that contains the cursor, or, if the cursor is, between lines, in the paragraph immediately below., Paragraphs aredelimited by blank lines, or by lines, beginning with a space or tab. Unjustification can be done, immediately after justification using the control-U key, combination., String searches are not sensitive to case. A search, begins at the current cursor position and wraps around, the end of the text. The most recent search string is, To, , The spell checker examines all words in the text. It then, offers each misspelled word for correction while highlighting, it in the text. Spell checking can be cancelled at any time., Alternatively, pico will substitute for the default spell, checking routine a routine defined by the SPELL, environment variable. The replacement routine should read, standard input and write standard output., The file browser is offered as an option in the "Read File", and "Write Out" command prompts. It is intended to help, in searching for specific files and navigating directory, hierarchies. Filenames with sizes and names of directories, in the current working directory are presented for selection., The current working directory is displayed on the top line, of the display while the list of available, commands takes up the bottom two. Several basic file, manipulation functions are supported: file renaming,, copying, and deletion., Movement commands:, Depending on your system, the arrow keys or the, backspace key may not work. Instead, you can use these, commands to perform the same tasks., , Hold down Ctrl key and press, , Delete a character, , backspace, , Instead of, backspace, , Move up a line, , p, , up arrow, , Move down a line, , n, , down arrow, , Move left one space, , b, , left arrow, , Move right one space, , f, , right arrow, , Move to the end of line, , e, , end, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 77
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Some pico editor options, , ^K Cut text, , ^C Cancel allows you to stop a process at any time. If, you make a mistake, just hold down the Ctrl key and, press c., , Cut a line of text. This option allows you to cut a full line, of text. By using the uncut command and your arrow, keys, you can then paste the cut text at another location, in your document. To cut specific text in a line or to cut, several lines of text, first select the text (see Selecting, Text on the next page)., , ^G get help, Get clear and concise assistance from the Pico help, in, case something unexpected happens or you need, additional information about a command., ^X Exit, , Selecting text, To select text for cutting and pasting use the following, steps:, , Exit Pico at anytime. If made changes to a file or worked, on a new file, but you havent saved the changes, you see, this message:, , Move the cursor to the beginning of the text to select, , Save modified buffer (ANSWERING "No" WILL DESTROY, CHANGES) (y/n)?, , Use the right arrow key or hold down Ctrl and press f to, highlight text, , Answering no (press n) will close Pico and bring you back, to the prompt without saving your file., , When you have highlighted the appropriate text, hold down, the Ctrl key and press k to cut it., , Answering yes (press y) will allow you to save the file, you've been working on (see Write Out section below for, details)., , Paste the text you cut, anywhere in your document, using, UnCut Text, , ^O WriteOut, Save the file without hassles or worries. Fill in the name, of the file beside the File Name to write: prompt. If the file, already has a name, then press enter., ^T To Files option lets to save the text over a file that, exists in the directory. By choosing the To Files option,, Pico takes you to a directory Browser., ^R Read File, Insert text from another file into your current text file. This, option allows you to search through your directories for a, file that you would like to add to your text. This option is, especially handy if you've saved a document and would, like to add its content to the new file you're working on., Text from the file you select is placed on the line directly, above your cursor., At the Insert file : prompt you may either type a file name, or use the Browser options., ^T To Files option lets you import a text file directly into, the file you're currently typing. By choosing the To Files, option, Pico takes you to a directory Browser., ^Y Prev Pg, Move quickly to the previous page. Although you could, just as easily press the up arrow key several times, this, command quickly jumps your cursor up one page., ^V Next Pg, Move quickly to the next page. Although you could just, as easily press the down arrow key several times, this, command quickly jumps your cursor down one page., 78, , Hold down the Ctrl key and press ^, , ^U UnCut Text, Paste text that previously cut. if use this option to undo, an accidental cut of text or place cut text at another location, in the document. The text you cut is pasted on the line, directly above the cursor., ^C Cur Pos, Indicate the current position of the cursor, relative to the, entire document. This is a helpful option if you'd like to, check exactly where in the document. The status line, indicates the following items:, [line 8 of 18 (44%), character 109 of 254 (42%)], ^J Justify, Even out lines of text. This command is handy when, accidentally type extra spaces between words or press, the key before reaching the end of a line. The option, evens the length of text lines automatically., ^U UnJustify, UnJustify lines of text. For the messy line look you can, always select the UnJustify option., ^W Where is, Find a particular string of text quickly. This option allows, you to do a word search in your text. This option is, especially handy for longer documents. If the word you, designated at the Search: prompt is found, it places the, cursor beside it., ^T To Spell, Check for spelling errors. The spell check option allows, to correct spelling errors throughout the document. If spell, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
Page 598 : checker finds a misspelled word or a word it doesn't, recognize (don't worry, this rarely happens), it will correct, the word. At the Edit a replacement: prompt, type in the, correct spelling of a word. However, if you don't want to, make any changes, simply press the enter key., Any words that have corrected but re-occur in the document, can be automatically replaced. At the Replace a with b?, [y]: prompt press y to replace all occurrences of the, misspelled word or n to ignore., Pine Editor, pine is a program for accessing email and newsgroups., Syntax, pine [options] [address, address], Description, pine is a screen-oriented message-handling tool. In its, default configuration, pine offers an intentionally limited, set of functions geared toward the novice user, but it also, has a growing list of optional power-user and personalpreference features. pine's basic feature set includes:, , • View, Save, Export, Delete, Print, Reply and Forward, messages., , • Compose messages in a simple editor (pico) with wordwrap and a spelling checker. Messages may be, postponed for later completion., , • Full-screen selection and management of message, folders., , • Address book to keep a list of long or frequently-used, , addresses. Personal distribution lists may be defined., Addresses may be taken into the address book from, incoming mail without retyping them., , • New mail checking and notification occurs, automatically., , • Context-sensitive help screens., pine supports MIME (Multipurpose Internet Mail, Extensions), an Internet Standard for representing, multipart and multimedia data in email. pine allows you to, save MIME objects to files, and in some cases, can also, initiate the correct program for viewing the object. It uses, the system's mailcap configuration file to determine what, program can process a particular MIME object type. pine's, message composer does not have multimedia capability, , itself, but any type of data file (including multimedia) can, be attached to a text message and sent, using MIME's encoding rules. This allows any group of, individuals with MIME-capable mail software to exchange, formatted documents, spread-sheets, image files, etc, via, Internet email., pine uses the "c-client" messaging API to access local, and remote mail folders. This library provides a variety of, low-level message-handling functions, including drivers for, a variety of different mail file formats, as well as routines, to access remote mail and news servers, using IMAP, (Internet Message Access Protocol) and NNTP (Network, News Transport Protocol). Outgoing mail is usually handed, off to the send mail program but it can optionally be posted, directly via SMTP., Examples, Pine, Launch pine., pine
[email protected], Launch pine, and immediately begin composing an email, addressed to
[email protected]., Joe editor, 'joe'- sounds like a comic strip. Actually, they are two other, text editors that I like and I think are a little easier to, manage. They're like 'vi' in that you use them to create, and edit non-formatted text, but they're a little more userfriendly. Using 'joe' 'joe' was created by Joseph Allen, so, that's why it's called Joe., The majority of joe's commands are based on the CTRL-K, keys and a third key. The most important of these is CTRLK-H which gets 'help'. Help shows the key combinations, to use with 'joe'., The most important thing about 'joe' is the logical concept, that you can just start writing if you want. Try writing, anything you want., To save it, press CTRL-K-D. To save and quit, CTRL-K-X., To quit without saving, CTRL-C, (without the K)., The feature of 'joe' is that if edit a file again, it will save the, previous file with a tilde on the end, like 'tryjoe~' That little, tilde file has saved times. 'joe' is a very good option for, writing those short text files., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 79
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IT & ITES, Related Theory for Exercise 1.5.27 & 1.5.28, COPA - Linux Operating System, Managing files and directories, Objectives: At the end of this lesson you shall be able to, • define manipulating files and directories, • define basic file commands, • explain other file commands, • define additional useful commands in linux OS., Manipulating files or directories, Using Linux isn't different from any other computer, operating system. You create, delete, and move files on, your hard drive in order to organize your information and, manage how your system works or looks. This section, shows you how to do these tasks quickly and easily., Although the graphical interface for Linux, the X Window, System, may offer drag and drop or multiple selections in, order to copy or delete files, many of the commands you'll, learn here form the base of these operations. It is worth, knowing how these programs work, even if you don't use, Linux in the console mode., Working with files, In this chapter we learn how to recognise, create, remove,, copy and move files using commands like file, touch, rm,, cp, mv and rename, etc…, All files are case sensitive, Files on Linux (or any Unix) are case sensitive. This means, that FILE1 is different from, file1, and /etc/hosts is different from /etc/Hosts (the latter, one does not exist on a typical Linux computer)., The file command, The file command attempts to classify each filesystem, object (i.e., file, directory or link) that is provided to it as, an argument (i.e., input). Thus, it can usually provide, immediate information as to whether some specified, object is, for example, a GIF89a image file, a directory, a, GNU tar archive, ASCII English text, a symbolic link, an, HTML document, an empty file, bzip2 compressed data,, an ELF 32-bit LSB executable, etc., File accomplishes this by probing each object with three, types of tests until one succeeds. The first is a filesystem, test, which uses the stat system call to obtain information, from the object's inode (which contains information about, a file). A system call is a request in a Unix-like operating, system for a service performed by the kernel (i.e., the, core of the operating system)., The second test checks to see if there is a magic number,, which is a number embedded at or near the beginning of, many types of files that indicates the file format(i.e., the, type of file)., , it is plain text (i.e., composed entirely of human-readable, characters), and, if so, what type of plain text, such as, HTML (hypertext markup language) or source code (i.e.,, the original version of a program as written by a human)., In this situation, file also attempts to determine the natural, language (e.g., English, Turkish or Japanese) that is used, in the file., A simplified version of file's syntax is, file [option(s)] object_name(s), File has several options, but it is most commonly used, without any of them. For example, information about a file, named file1 that is located in the in the current directory, (i.e., the directory in which the user is currently working), could be obtained by merely typing the following and, pressing the RETURN key:, file file1, Information about the types of all of the files in the, current directory can be obtained by using the star wildcard, to represent every object in that directory as, follows:, file *, Likewise, information about all of the files in another, directory can be obtained by using that directory as an, argument and following it immediately by a forward slash, and the star wildcard. For example, the following, classifies all of the objects in the /boot directory:, file /boot/*, The square brackets wildcard can be used together with, the star wildcard to show the file types for only those, objects whose names begin with specified letters or with, a specified range of letters. For example, the following, would show only those objects in the current directory, whose names begin with letters a through g:, file [a-g]*, The -k option tells file to not stop at the first successful, test, but to keep going; this can result in the reporting of, additional information about some filesystem objects. The, -b (i.e., brief) option tells file to not prepend filenames to, output lines, which can be useful when compiling statistics, about file types. The -v option returns information about, the version of file that is installed., , In the event that the first two tests fail to determine the, type of a file, language tests are employed to determine if, 80, , Copyright @ NIMI Not to be Republished
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Creating files and directories command, mkdir command, The mkdir command is is used to create new, directories., A directory, referred to as a folder in some operating, systems, appears to the user as a container for other, directories and files. However, Unix-like operating, systemstreat directories as merely a special type of file, that contains a list of file names and their corresponding, inode numbers. Each inode number refers to an inode,, which is located in inode tables (which are kept at, strategic locations around the filesystem) and which, contains all information about a file (e.g., size,, permissions and date of creation) except its name and, the actual data that the file contains., mkdir has the following example, $ mkdir example, , mkdir -m 777 dir_4, The first digit represents the owner, the second represents, the group and the third represents other users. The number, 7 represents all three types of permission (i.e., read, write, and execute), 6 stands for read and write only, 5 stands, for read and execute, 4 is read only, 3 is write and execute,, 2 is write only, 1 is execute only and 0 is no permissions., Thus, for example, to create a new directory named dir_5, for which the owner has read and write permissions, the, group has read permission and other users have no, permissions, the following would be used:, mkdir -m 640 dir_5, , $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, directory_name is the name of any directory that the user, is asking mkdir to create. Any number of directories can, be created simultaneously., Thus, for example, the following command would create, three directories within the current directory (i.e., the, directory in which the user is currently working) with the, names dir_1, dir_2 and dir_3:, mkdir dir_1 dir_2 dir_3, If a directory name provided as an argument (i.e., input) to, mkdir is the same as that of an existing directory or file in, the same directory in which the user is asking mkdir to, create the new directory, mkdir will return a warning, message such as mkdir: cannot create directory `dir_1':, File exists and will not create a file with that name., However, it will then continue to create directories for any, other names provided as arguments., It is necessary for a user to have write permission (i.e.,, permission from the system to create or change a file or, directory) in the parent directory (i.e., the directory in which, the new directory is to be created) in order to be able to, create a new directory., Directories created by mkdir automatically include two, hidden directories, one representing the directory just, created (and represented by a single dot) and the other, representing its parent directory (and represented by two, consecutive dots). This can be seen by using the ls (i.e.,, list) command with its -a option, which tells ls to show all, directories and files, (including hidden ones) in any directory, provided to it as an argument, or in the current directory if, there are no arguments, i.e.,, ls -a, , a program) permissions enabled for the owner (i.e., the, creator of the directory by default) and group and the read, and execute permissions enabled for other users. Thus,, for example, to create a directory named dir_4 for which, all three types of permissions were enabled for all users,, the sequence 777 would be employed after -m, for example:, , The -p (i.e., parents) option creates the specified, intermediate directories for a new directory if they do not, already exist. For example, it can be used to create the, following directory structure:, mkdir -p food/fruit/citrus/oranges, It is very easy to confirm that this series of directories has, been created by using the du (i.e., disk usage) command, with the name of the first directory as an argument. In the, case of the above example this would be, du food, Other options include -v (i.e., verbose), which returns a, message for each created directory, --help, which returns, brief information about mkdir, and --version, which returns, the version number of the currently installed mkdir program, touch command, The touch command updates the access and modification, times of each FILE to the current system time., If you specify a FILE that does not already exist, touch, creates an empty file with that name., If the FILE argument is a dash ("-") is handled specially, and causes touch to change the times of the file associated, with standard output., $ touch file1 file2 file3, $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file2, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, A feature of touch is that, in contrast to some commands, such as cp (which is used to copy files and directories), and mv (which is used to move or rename files and, , mkdir's -m option is used to control the permissions of, new directories. New directories are by default created, with the read, write and execute (i.e., run as a program if, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 81
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directories), it does not automatically overwrite (i.e., erase, the contents of) existing files with the same name. Rather,, it merely changes the last access times for such files to, the current time., Several of touch's options are specifically designed to allow, the user to change the timestamps for files. For example,, the -a option changes only the access time, while the -m, option changes only the modification time. The use of both, of these options together changes both the access and, modification times to the current time, for example:, touch -am file3, The -r (i.e., reference) option followed directly by a space, and then by a file name tells touch to use that file's time, stamps instead of current time. For example, the following, would tell it to use the times of file4 for file5:, touch -r file4 file5, The -B option modifies the timestamps by going back the, specified number of seconds, and the -F option modifies, the time by going forward the specified number of seconds., For example, the following command would make file7 30, seconds older than file6., touch -r file6 -B 30 file7, The -d and -t options allow the user to add a specific last, access time. The former is followed by a string (i.e.,, sequence of characters) in the date, month, year,, minute:second format, and the latter uses a, [[CC]YY]MMDDhhmm[.ss] format. For example, to change, the last access time of file8 to 10:22 a.m. May 1, 2005, 1, May 2005 10:22 would be enclosed in single quotes and, used as follows, i.e.,:, touch -d '1 May 2005 10:22' file8, Partial date-time strings can be used. For example, only, the date need be provided, as shown for file9 below (in, which case the time is automatically set to 0:00):, touch -d '14 May' file9, Just providing the time, as shown below, automatically, changes the date to the current date:, touch -d '14:24' file9, The most commonly used way to view the last modification, date for files is to use the ls command with its -l option., For example, in the case of a file named file10 this would, be, ls -l file10, The complete timestamps for any file or directory can be, viewed by using the stat command. For example, the, following would show the timestamps for a file named file11:, stat file11, The --help option displays a basic list of options, and the, --version option returns the version of the currently installed, touch program., , 82, , Copy, move and remove commands, Copy command, The cp command is used to copy files and directories., The copies become independent of the originals (i.e., a, subsequent change in one will not affect the other)., cp's basic syntax is, $cp source destination, As a safety precaution, by default cp only copies files and, not directories. If a file with the same name as that assigned, to the copy of a file (or a directory with the same name as, that assigned to the copy of a directory) already exists, it, will be overwritten (i.e., its contents will be lost). However,, the owner, group and permissions for the copy become, the same as those of the file with the same name that it, replaced. The last access time of the source file and the, last modification time of the new file are set to the time, the copying was performed., When a copy is made of a file or directory, the copy must, have a different name than the original if it is to be placed, in the same directory as the original. However, the copy, can have the same name if it is made in a different directory., Thus, for example, a file in the current directory (i.e., the, directory in which the user is currently working) named, file1 could be copied with the same name into another, directory, such as into /home/john/, as follows:, cp file1 /home/john/file1, Any number of files can be simultaneously copied into, another directory by listing their names followed by the, name of the directory. cp is an intelligent command and, knows to do this when only the final argument (i.e., piece, of input data) is a directory. The files copied into the, directory will all have the same names as the originals., Thus, for example, the following would copy the files named, file2, file3 and file4 into a directory named dir1:, cp file2 file3 file4 dir1, The -r (i.e., recursive) option, which can also be written, with an upper case R, allows directories including all of, their contents to be copied. (Directories are not copied by, default in order to make it more difficult for users to, accidentally overwrite existing directories which have the, same name as that assigned to the copy being made and, which might contain critical directory structures or, important data.) Thus, for example, the following command, would make a copy of an existing directory called dir2,, inclusive of all it contents (i.e., files, subdirectories, their, subdirectories, etc.), called dir3:, cp -r dir2 dir3, The -i (i.e., interactive) option prompts the user in the event, that any name assigned to a copy is already in use by, another file and that file would thus be overwritten. Entering, the letter y (either lower case or upper case) in response, to the prompt causes the command to continue; any other, answer prevents the command from overwriting the file., Thus, for example, if it is desired to make a copy of a, directory called dir4 and call it dir5 and if a directory named, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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dir4 already exists, the following would prompt the user, prior to replacing any files with identical names in the latter, directory:, cp -ri dir4 dir5, The -a option preserves as much of the structure and, attributes of the original directory and its contents as, possible in the new directory and is thus useful for creating, archives. It is similar to the -r option in that it copies, directories recursively; however, it also never follows, symbolic links. It is equivalent to the -rdp combination of, options., All the files in a directory can be copied to another directory, by using the star wildcard. The star character represents, any single character or any combination of characters., Thus, for example, the following would copy all of the files, in a directory named dir6 into another existing directory, called dir7:, cp dir6/* dir7, cp can also be used with the star wildcard or other pattern, matching characters to selectively copy files and, directories. For example, to copy all of the files in the, current directory that have the filename extension .html, into another existing directory called dir8, the following, would be used:, cp *.html dir8, In this case, the star wildcard represents anything whose, name ends with the .html extension., Among the other options for cp are -b, which makes backup, copies of each destination file, -f (i.e., force), which removes, destination files that cannot be opened and tries again, s, which makes symbolic links instead of copying, -u (i.e.,, update), which copies only if the source file is newer than, the destination file or if the destination file is missing, -v, (i.e., verbose), which makes brief comments about what, is going on, and -x, which tells cp to stay on the same, filesystem., Move command, The mv command is used to rename and move files and, directories. Its general syntax is:, $ mv source destination, The arguments are names of files and directories. If two, file names are provided as arguments, mv renames the, first as the second. If a list of arguments is provided and, the final argument in the sequence is the name of an, existing directory, mv moves all of the other items into, that directory. If the final argument is not an existing, directory and more than two arguments are provided, an, error message is returned., If the destination file is located in the same directory as, the source file, then the source file can only be renamed., If both are in different directories, then the source file is, moved to the directory named in the destination argument,, in which it can keep its original name or be assigned a, new name. If the target is a directory, then the source file, , or directory is moved into that directory and retains its, original name., Thus, for example, the following would rename a file called, file1 to file2, while keeping it in the current directory (i.e.,, the directory in which the user is currently working):, mv file1 file2, The following would move a file named file3, without, changing its name, from the current directory to an existing, subdirectory of the current directory named dir1:, mv file3 dir1/file3, mv can be used to move any number of files and directories, simultaneously. For example, the following command, moves all files and directories, including all the contents, of those directories, from the current directory to the, directory /home/alice/new/:, mv * /home/alice/new/, The asterisk is a wildcard character that represents any, string (i.e., sequence of characters). Thus, in the above, example it represents the name of every file and directory, in the current directory., mv makes it as easy to move a file or directory up the, hierarchy of directories (i.e., closer to the root directory), as down it. For example, the following would move a file, named file4, which is currently located in the subsubdirectory dir/dir/ of the user's home directory, to the, top level in the user's home directory:, mv dir/dir/file4 ~, The root directory is the directory that contains all other, directories on a Unix-like operating system and which is, at the top of the hierarchy of directories. A user's home, directory is the directory in which a user finds itself by, default after logging into the system and which can be, represented by the tilde (wavy horizontal linecharacter)., By default, mv does not provide any confirmation on the, display screen if its action is completed without problems., This is consistent with the rule of silence tenet of the Unix, philosophy., Thus it is wise for users new to Unix-like operating, systems to always use the -i option, which makes mv, interactive in the situation in which files and/or directories, with the same name already exist in the destination, directory. For example, the above command would be made, interactive as follows:, mv -i * /home/alice/new/, Among mv's few other options are -b, which tells it to make, a backup copy of each file that would otherwise be, overwritten or removed, and -v, which tells it to beverbose, and display the name of each file before moving it. Detailed, information (including all options) about mv can be obtained, by using its --help option, and information about the current, version can be obtained by using its --version option., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 83
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Remove or Delete, , begins with a dash or hyphen. For example, the following, removes a directory named -dir1:, , $ rmdir, 'rmdir' command removes any empty directories, but, cannot delete a directory if a file is present in it. To use, 'rmdir' command, you must first remove all the files present, the directory you wish to remove (and possibly directories, if any)., Remove files and directories, The rm (i.e., remove) command is used to delete files and, directories on Linux and other Unix-like operating systems., The general syntax for rm is:, rm [options] [-r directories] filenames, The items in square brackets are optional. When used, just with the names of one or more files, rm deletes all, those files without requiring confirmation by the user. Thus,, in the following example, rm would immediately delete the, files named file1, file2 and file3, assuming that all three, are located in the current directory (i.e., the, directory in which the user is currently working):, rm file1 file2 file3, Error messages are returned if a file does not exist or if, the user does not have the appropriate permission to delete, it. Write-protected files prompt the user for a confirmation, (with a y for yes and an n for no) before removal. Files, located in write-protected directories can never be removed,, even if those files are not write-protected., The -f (i.e., force) option tells rm to remove all specified, files, whether write-protected or not, without prompting the, user. It does not display an error message or return error, status if a specified file does not exist. However, if an, attempt is made to remove files in a write-protected, directory, this option will not suppress an error message., The -i (i.e., interactive) option tells rm to prompt the user, for confirmation before removing each file and directory. If, both the -f and -i options are specified, the last one specified, takes affect., As a safety measure, rm does not delete directories by, default. In order to delete directories, it is necessary to, use the -r option, which is the same as the -R option. This, option recursively removes directories and their contents, in the argument list; that is, the specified directories will, first be emptied of any subdirectories (including their, subdirectories and files, etc.) and files and then removed., The user is normally prompted for removal of any writeprotected files in the directories unless the -f option is, used., If a file encountered by rm is a symbolic link, the link is, removed, but the file or directory to which that link refers, will not be affected. A user does not need write permission, to delete a symbolic link, as long as the user has write, permission for the directory in which that link resides., The rm command supports the -- (two consecutive dashes), parameter as a delimiter that indicates the end of the, options. This is useful when the name of a file or directory, 84, , rm -r -- -dir1, Other options include -v (i.e., verbose), which provides, additional information about what is happening, --help,, which provides basic documentation about rm, and -version, which tells the version of rm that is currently in, use. Some differences exist among the various versions, of rm, so it is always wise to read the documentation for, the particular system., The rmdir command differs from rm in that it is only used, to remove empty directories, The rmdir command, The rmdir command is used to remove empty directories, in Linux, The syntax for rmdir is, rmdir [option] directory_names, When used without any options, rm will delete any empty, directories whose names are supplied as arguments (i.e.,, inputs) regardless of whether such directories have write, permission or not. Thus, for example, the following, command would remove two empty directories named dir1, and dir2 that are located in the current directory (i.e., the, directory in which the user is currently working):, rmdir dir1 dir2, The ability to remove only empty directories is a built-in, safeguard that helps prevent the accidental loss of data., This is important because once deleted, it is extremely, difficult or impossible to recover deleted data on Unix-like, operating systems1., The -p (i.e., parents) option tells rmdir to remove the parent, directories of the specified directory if each successive, parent directory will, in turn, become empty and if each, parent directory has write permission. Thus, for example,, the following would remove dir5, dir4 and dir3 if dir5 were, empty, dir4 only contained dir5 and dir3 only contained, dir4 (which, in turn, contained dir5):, rmdir -p dir3/dir4/dir5, This provides a symmetry with the -p option of the mkdir, command, which is used to create directories. Thus, the, above set of nested directories could be easily created, with the following:, mkdir -p dir3/dir4/dir5, In contrast to the rm command, which is used to delete, both files and directories, there is no -r option for rmdir. at, least on the GNU version that is standard on Linux. That, option allows rm to recursively delete a directory by first, deleting all of its contents, beginning with those in the, lowest levels of subdirectories. Thus, if a user wants to, remove an entire directory structure, it is usually most, efficient to use rm with its -r option rather than trying to, first remove the contents of each directory, its, subdirectories, etc., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Three options that rmdir shares with rm are -v (i.e., verbose),, which provides additional information about what is, happening, --help, which provides basicdocumentation, about rmdir, and --version, which tells the version of rmdir, that is currently in use. Some differences exist among the, various versions of rmdir, so it is always wise to read the, documentation for the particular system., Listing and combining files with the cat command, The cat (concatenate file) command is used to send the, contents of files to your screen. This, command may also be used to send files' contents into, other files. Hour 6 covers terms such as standard input,, standard output, and redirection, and this section shows, you some basic uses for this command., Although cat may be useful for reading short files, it is, usually used to either combine, create, overwrite, or, append files. To use cat to look at a short file, you can, enter, $ cat test.txt, This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., The cat command also has a number of options. If you'd, like to see your file with line, numbers, perhaps to note a specific phrase, you can use, the -n option:, , $ cat test.txt test2.txt, The output will be exactly the same as if had used a, wildcard. But looking at several files is only one way to, use cat. You can also use the cat command with the, redirection operator > to combine files. For example, if, you would like to combine test.txt and test2.txt into a, third file called test3.txt, you can use, $ cat test* > test3.txt, check the result with, # ls -l test*, In this case, user first decide whether you want the contents, of test.txt to go into test2.txt, or the contents of test2.txt, to go into test.txt . Then, using cat with the >> redirection, operator, you might type, $ cat test.txt >> test2.txt, This appends the contents of test.txt to the end of the, test2.txt . To check the results, use cat again:, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., Note that if you had entered the command., , $ cat -n test.txt, , • This text file was created by the cat command., • Cat could be the world's simplest text editor., • If you read this book, you'll learn how to use cat., • This is the last line of text in this file., and also use cat to look at several files at once, because, cat accepts wildcards, for example:, , $ cat -n test.txt >> test2.txt, The test2.txt file would look like, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., , $ cat -n test*, , • This text file was created by the cat command., , • This text file was created by the cat command., , • Cat could be the world's simplest text editor., , • Cat could be the world's simplest text editor., , • If you read this book, you'll learn how to use cat., , • If you read this book, you'll learn how to use cat., , • This is the last line of text in this file., , • This is the last line of text in this file., • This file was also created by cat., , Finally, here's a trick you can use if you want to create a, short text file without running a word processor or text, editor. Because the cat command can read the standard, input (more about this in Hour 6), you can make the cat, command create a file and fill it with your keystrokes., , • This is the last line of test2.txt., , Here's how:, , • This is the first line of test2.txt., , As you can see, cat has also included a second file in its, output, and has numbered each line of the output, not, each file. Note that also see both files with, , $ cat > myfile.txt, Now, enter some text:, $ cat > myfile.txt, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 85
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This is the cat word processor., This is the end of the file., Then, when you're done typing, press Ctrl+D to close the, file. To see if this works, try, $ ls -l myfile.txt, -rw-rw-r-- 1 bball bball 61 Nov 12 18:26 myfile.txt, $ cat myfile.txt, This is the cat word processor., This is the end of the file., user should also know that the cat command will print out, the contents of any file, and not, just text files. Although cat may be useful to look at one or, several short files,, Other file commands, The clear Command, The clear command is used to remove all previous, commands and output from consoles and terminal, windows in Unix-like operating systems., A console is an all-text mode user interface that, occupies the entire screen of the display device and which, does not sit on top of a graphical user interface (GUI). A, terminal window is a text-only window in a GUI that, emulates a console and which can be opened by clicking, the appropriate icon (i.e., small image) or menu item., , As another example, the following displays the man page, about the man pages:, man man, man automatically sends its output through a pager,, usually the program less. A pager is a program that causes, the output of any program to be displayed one screenful, at a time, rather than having a large amount of text scroll, down the screen at high (and generally unreadable) speed., less writes a colon at the bottom of the screen to indicate, the end of the on-screen page. The user can move to the, next page by pushing the space bar and can return to the, previous page by pressing the b key. Pressing the q exits, the man pages and returns the user to the shell program., Each man page is a self-contained article that is divided, into a number of sections, the headers for which are labeled, with upper case letters. The sections for commands are, typically something like NAME, SYNOPSIS,, DESCRIPTION, OPTIONS, AUTHOR, BUGS,, COPYRIGHT, HISTORY and SEE ALSO, although there, may be some differences according to the particular, command. Some of these might be broken down into, subsections, particularly OPTIONS in the case of a, command that has numerous options., Also, the man pages as a whole are organized into, sections, each containing pages about a specific category, of topics as shown below. The section to which an article, belongs is indicted in parenthesis in the top line, before, the NAME header., , Clear is one of the very few commands in Unix-like, operating systems that accepts neither options nor, arguments (i.e., input files). That is, it is only used as, follows:, , 1. executable programs or shell commands, , Clear, , 4. special files (i.e., devices in the /dev directory), , After the clear command has been issued, all that, remains on the display screen is the command prompt in, the upper left hand corner. A command prompt, also, referred to as a prompt, is a short text message at the, start of a line that informs the user that the system is, ready for the next command, data element or other, input., , 5. file formats, , The descriptions are rather terse, and they can seem, somewhat cryptic to new users. However, users typically, find them to be increasingly useful as they become more, familiar with them and gain experience in the use of Unixlike operating systems., , Some topic names will have multiple articles, depending, on context. For instance, there are two articles for mount,, one corresponding to its use as a command in system, management (i.e., to logically attach partition or other, devices to the main filesystem) and the other for use in, the C programming language. Generally, the most, commonly used topic is displayed by default, and there, are references to any other topics with the same name in, the SEE ALSO section at the bottom of the final on-screen, page., , The man command itself is extremely easy to use. Its, basic syntax is, man [option(s)] keyword(s), man is most commonly used without any options and, with only one keyword. The keyword is the exact name of, the command or other item for which information is desired., For example, the following provides information about the, ls command (which is used to list the contents of any, specified directory):, man ls, 86, , 2. system calls, 3. library routines, , 6. games, 7. macro packages, 8. system administration commands, 9. kernel routines, , The syntax to specify an article from a particular section, is:, man section_number keyword, , Thus, for example, the following would display the article, about mount from Section 2 instead of from the default, Section 8:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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man 2 mount, The -w and -W options tell man to not actually display the, man pages, but to provide the location(s) of the file(s) that, would be formatted or displayed. If noarguments (i.e., input, files) are provided, a list of directories that is searched by, man for man pages is returned., The -f option produces the same output as the whatis, command. whatis provides very brief descriptions of, commands from a database that is automatically created, from the first line of the NAME section of each relevant, man page., The Whoami and who command, The whoami command writes the user name (i.e., login, name) of the owner of the current login session to standard, output. Standard output is, by default, the display screen,, unless redirected to a file, printer, etc., , as additional information about each of those users, (including login times and terminal numbers). It also, differs in that, in the event of a change in ownership of a, login session through the use of the su command, it, reports the original owner of the session, whereas whoami, provides the user name of the effective (i.e., current) owner, of the session., stat command, File Stat - Display Information About File, For example, to find out more information about, 101hacks.txt file, execute the stat command as shown, below., $ stat 101hacks.txt, File: `/home/sathiyamoorthy/101hacks.txt', Size: 854, , Blocks: 8 IO Block: 4096 regular file, , whoami is particularly useful when using shells such as, ash and sh that do not show the name of the current user, in the command prompt (a short text message at the start, of the command line on an all-text display). It is also useful, for confirming the current owner of a session after using, the su (i.e., substitute user) command, which changes, the owner of the session without the original owner having, to first log out., , Device: 801h/2049d, , A shell is a program that provides the traditional, text-only, user interface forUnix-like operating systems. Its primary, function is to read commands that are typed into a console, (i.e., an all-text display mode) or terminal window(an alltext window in a GUI) and then execute (i.e., run) them., , Details of Linux stat command output, , The formal syntax for whoami is:, , • Blocks: 8 - Total number of blocks used by this file., , whoami [option], When used without any options or redirection, as it usually, is, i.e.,, Whoami, , Inode: 1058122, , Links: 1, , Access: (0600/-rw-------) Uid: ( 1000/ sathiya), Gid: ( 1000/ sathiya), Access: 2009-06-28 19:29:57.000000000 +0530, Modify: 2009-06-28 19:29:57.000000000 +0530, Change: 2009-06-28 19:29:57.000000000 +0530, , • File: `/home/sathiyamoorthy/101hacks.txt' - Absolute, path name of the file., , • Size: 854 - File size in bytes., • IO Block: 4096 - IO block size for this file., • Regular file - Indicates the file type. This indicates, , that this is a regular file. Following are available file, types., , and followed by pressing the ENTER key, whoami displays, on the monitor screen the user name of the owner of the, current session., , − regular file. ( ex: all normal files )., , There are only two options for whoami: --help and --version., The former outputs the very brief description that is, contained in the man (i.e., built-in system manual) pages,, and the latter outputs the number of the version currently, installed on the system., , − socket. ( ex: sockets )., , whoami produces the same result as the id command, (which by default provides more detailed information about, the current user than does whoami) when id is used with, its -u and -n options, i.e.,, , − character special file. ( ex: terminal device file)., , id -un, The -u option tells id to provide only the identification for, the current owner of the session, and the -n option tells it, to present that identification as the user name instead of, as a number., The who command differs from whoami in that it provides, a list of all users currently logged into the system as well, , − directory. ( ex: directories )., − symbolic link. ( ex: symbolic links. ), − block special file ( ex: hard disk )., • Device: 801h/2049d - Device number in hex and device, number in decimal, , • Inode: 1058122 - Inode number is a unique number for, , each file which is used for the internal maintenance by, the file system., , • Links: 1 - Number of links to the file, • Access: (0600/-rw---): Access specifier displayed in, , both octal and character format. Let us see explanation, about both the format., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 87
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• Uid: ( 1000/ sathiya) - File owner's user id and user, , between. Thus, the following command would produce the, same result:, , • Gid: ( 1000/ sathiya) - File owner's group id and group, , head -n 15 aardvark armadillo, , name are displayed., name are displayed., , • Access: 2009-06-28 19:29:57.000000000 +0530 - Last, access time of the file., , • Modify: 2009-06-28 19:29:57.000000000 +0530 - Last, modification time of the file., , • Change: 2009-06-28 19:29:57.000000000 +0530 - Last, change time of the inode data of that file., , Dir Stat - Display Information About Directory You can, use the same command to display the information about, a directory as shown below., $ stat /home/ramesh, , In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell head how many lines to, return. Thus, the following would produce the same, result as the above commands:, head -15 aardvark armadillo, head can also return any desired number of bytes (i.e., a, sequence of eight bitsand usually long enough to represent, a single character) from the start of each file rather than a, desired number of lines. This is accomplished using the coption followed by the number of bytes desired. For, example, the following would display the first five bytes of, each of the two files provided:, , File: `/home/ramesh', , head -c 5 aardvark anteater, , Size: 4096 Blocks: 8 IO Block: 4096 directory, , When head counts by bytes, it also includes the newline, character, which is anon-printing (i.e, invisible) character, that is designated by a backslash and the letter n (i.e.,, \n). Thus, for example, if there are three new, blank lines, at the start of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or on, paper)., , Device: 803h/2051d Inode: 5521409 Links: 7, Access: (0755/drwxr-xr-x) Uid: ( 401/ramesh), Gid: (401/ramesh), Access: 2009-01-01 12:17:42.000000000 -0800, Modify: 2009-01-01 12:07:33.000000000 -0800, Change: 2009-01-09 12:07:33.000000000 -0800, The head command reads the first few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the display screen)., , The number of bytes or lines can be followed by a, multiplier suffix. That is, adding the letter b directly after, the number of bytes multiplies it by 512, kmultiplies it by, 1024 and m multiplies it by 1048576. Thus, the following, command would display the first five kilobytes of the file, aardvark:, , head's basic syntax is:, , head -c5k aardvark, , head command, , head [options] [file(s)], The square brackets indicate that the enclosed items are, optional. By default, head returns the first ten lines of each, file name that is provided to it., For example, the following will display the first ten lines of, the file namedaardvark in the current directory (i.e., the, directory in which the user is currently working):, head aardvark, If more than one input file is provided, head will return the, first ten lines from each file, precede each set of lines by, the name of the file and separate each set of lines by one, vertical space. The following is an example of using head, with two input files:, head aardvark armadillo, If it is desired to obtain some number of lines other than, the default ten, the -noption can be used followed by an, integer indicating the number of lines desired. For example,, the above example could be modified to display the first, 15 lines from each file:, head -n15 aardvark armadillo, , The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter ccannot be omitted as, can the letter n, because in such case head would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like head: aardvark: invalid number of bytes:, head -c aardvark, If head is used without any options or arguments (i.e., file, names), it will await input from the keyboard and will, successively repeat (i.e., each line will appear twice) on, the monitor screen each of the first ten lines typed on the, keyboard. If it were desired to repeat some number of, lines other than the default ten, then the -n option would, be used followed by the integer representing that, number of lines (although, again, it is not necessary to, include the letter n), e.g.,, head -n3, As is the case with other command line (i.e., all-text mode), programs in Linuxand other Unix-like operating systems,, the output from head can redirectedfrom the display monitor, to a file or printer using the output redirection operator, (which is represented by a rightward-pointing angular, , -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, 88, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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bracket). For example, the following would copy the first, 12 lines of the file Yuriko to the fileDecember:, head -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two consecutive rightward pointing angle brackets) could, be used to add the output from head to the end of a file, with that name if it already existed (or otherwise create a, new file with that name), i.e.,, head -n 12 Yuriko >> December, The output from other commands can be sent via a pipe, (represented by thevertical bar character) to head to use, as its input. For example, the following sends the output, from the ls command (which by default lists the names of, the files and directories in the current directory) to head,, which, in turn, displays the first ten lines of the output that, it receives from ls:, ls | head, This output could easily be redirected, for example to the, end of a file namedfile1 as follows:, ls | head >> file1, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reverse alphabetic order, prior to appending file1:, ls | head | sort -r >> file1, The -q (i.e., quiet) option causes head to not show the file, name before each set of lines in its output and to eliminate, the vertical space between each set of lines when there, are multiple input sources. Its opposite, the -v (i.e., verbose), option, causes head to provide the file name even if there, is just a single input file., The tail command is similar to the head command except, that it reads the final lines in files rather than the first, lines., As is the case with other commands on Unix-like operating, systems, additional information can be obtained about head, and tail by using the man and infocommands to reference, the built-in documentation, for example, man head, or, info tail, tail command, The tail command reads the final few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the monitor screen)., The basic syntax for tail is:, tail [options] [filenames], $ tail -n 4 /etc/passwd, , The square brackets indicate that the enclosed items are, optional. By default, tail returns the final ten lines of each, file name that is provided to it., For example, the following command will print (traditional, Unix terminology for write) the last ten lines of the file, named aardvark in the current directory (i.e., the director, in which the user is currently working) to the display, screen:, tail aardvark, If more than one input file is provided, tail will print the last, ten lines from each file to the monitor screen. Each set of, lines will be preceded by the name of the file and separated, by one vertical space from other sets of lines. The following, is an example of using tail with multiple input files:, tail file1 file2 file3, If it is desired to print some number of lines other than the, default ten, the -n option can be used followed by an integer, indicating the number of lines desired. For example, to, print the final 15 lines from each file in the above example,, the command would be modified as follows:, tail -n15 file1 file2 file3, -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, between. Thus, the following command would produce the, same result:, tail -n 15 file1 file2 file3, In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell tail how many lines to print. Thus, the, following would produce the same result as the above, commands:, tail -15 file1 file2 file3, tail can also print any desired number of bytes (i.e., a, sequence of eight bits and usually long enough to represent, a single character) from the end of each file rather than a, desired number of lines. This is accomplished using the c option followed by the number of bytes desired. For, example, to view the final five bytes of each of the two files, aardvark and anteater, the following command would be, used:, tail -c 5 file1 file2, When tail counts by bytes, it also includes the newline, character, which is a non-printing (i.e, invisible) character, that is designated by a backward slash and the letter n, (i.e., \n). Thus, for example, if there are three new, blank, lines at the end of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or paper)., The number of bytes or lines can be followed by a multiplier, suffix. That is, adding the letter b directly after the number, of bytes multiplies it by 512, k multiplies it by 1024 and m, multiplies it by 1048576. Thus, the following command, would print the last five kilobytes of the file aardvark:, tail -c5k file1, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 89
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The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter c cannot be omitted as, can the letter n, because in such case tail would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like tail: aardvark: invalid number of bytes:, tail -c file1, If tail is used without any options or arguments (i.e., inputs),, it will await input from the keyboard and will successively, repeat (i.e., each line will appear twice) on the monitor, screen each of the final ten lines typed on the keyboard. If, it were desired to repeat some number of lines other than, the default ten, then the -n option would be used followed, by the integer representing that number of lines (although,, again, it is not necessary to include the letter n), e.g.,, tail -n3, As is the case with other command line (i.e., all-text mode), programs in Unix-like operating systems, the output of, tail can be redirected from the monitor to a file or printer, using the redirection operator (which is represented by a, rightward pointing angular bracket). For example, the, following would write the final 12 lines of the file Yuriko to, the file December:, tail -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two rightward pointing angular brackets) could be used to, add the output from tail to the end of a file with that name, if it already existed (or otherwise create a new file with, that name), i.e.,, tail -n 12 Yuriko >> December, The output from other commands can be piped (i.e., sent), to tail to use as its input. For example, the following sends, the output from the ls command (which by default lists the, names of the files and directories in the current directory), to tail, which, in turn, prints the final ten lines of the output, that it receives from ls to the monitor screen:, ls | tail, , Tail can be instructed to begin printing from some number, of lines or bytes from the start of a file by preceding the, number with a plus sign instead of a minus sign. For, example, the following would print each of the designated, files to the display monitor beginning with the seventh line, and until the end:, tail +7 file1 file2 file3, The c option could be used to tell tail to print each of the, designated files beginning with the seventh byte instead, of the seventh line:, tail +7c file1 file2 file3, A particularly common application for tail is examining the, most recent entries in log files. This is because the newest, entries are appended to the ends of such files, which tail, excels in showing. As log files can be a rather long, this, can eliminate a lot of scrolling that would be necessary if, some other command were used to read them. For, example, the most recent entries to the log /var/log/, messages can easily be viewed by using the, following:, tail /var/log/messages, wc command, The wc (i.e., word count) command by default counts the, number of lines, words and characters in text., wc defines a word as a set of contiguous letters, numbers, and/or symbols which are separated from other characters, by one or more spaces, tabs and/or newline characters, (which are generated when the RETURN key is pressed)., When counting the number of characters, all characters, are counted, not only letters, numbers and symbols, but, also spaces, tabs and newline characters. A line is only, counted if it ends with a newline character., wc's syntax is, , This output could easily be redirected, for example to a, file named last_filenames as follows:, ls | tail >> last_filenames, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reversealphabetic order, prior to writing to a file:, ls | tail | sort -r >> last_filenames, The -q (i.e., quiet) option causes tail to not print the file, name before each set of lines and to eliminate the vertical, space between each set of lines when there are multiple, input sources. The -v (i.e., verbose) option causes tail to, print the file name even if there is just a single input file., 90, , Tail could be viewed as a counterpart of the head command,, which always starts reading from the beginning of files, and which can continue until any specified distance from, the beginning. However, there are a few differences. Perhaps, the most useful of these is that tail is somewhat more, flexible in that, in addition to being able to start reading, any specified distance from the end of a file, it can also, start at any specified distance from the beginning of a file., , wc [options] [file_name(s)], The items in square brackets are optional. If no file names, are provided, wc reads from its standard input, which by, default is text entered at the keyboard., This can be seen by typing., wc, at the command line (i.e., in the all-text mode), pressing, the ENTER key to move to a new line and then typing, some text on one or more lines. The command isexecuted, (i.e., run) by pressing the ENTER key again and then, pressing the CONTROL and d keys simultaneously. This, causes wc to write in a new line (under the lines of text), its count of the numbers of lines, words and characters in, the text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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The following command counts the number of lines, words, and characters in a file named file1 that resides in the, current directory (i.e., the directory in which the user is, currently working) and likewise writes them, followed by, the name of the file, to standard output, which is by default, the display monitor:, , cat file6, grep command, grep is used to search text for patterns specified by the, user. It is one of the most useful and powerful commands, on Linux and other Unix-like operating systems., grep's basic syntax is:, , wc file1, wc can provide its output for multiple files by listing the, name of each separated by a space. For example,, wc file1 file2 file3, The numbers of lines, words and characters for each file, along with its name will be displayed on a separate line, and in the order that the files are listed as arguments(i.e.,, input files). In the case of multiple arguments such as, this, wc also provides an additional line that shows the, total number of lines, words and characters for all the files., Likewise, wc can provide a count for all of the text files, within a directory. This is accomplished by using the star, wildcard character, which represents everythingand is, designated by an asterisk ( * ). For example, the following, will display the number of lines, words and, characters for each file in the current directory (which is, represented by a dot) as well as totals for all files in the, directory:, wc . *, wc has only a few options, the most commonly used of, which restrict the information it provides. The -l option tells, wc to count only the number of lines, the -woption tells it, to count only the number of words, the -m option tells it to, count only the number of characters and the -c option, tells wc to count only the number ofbytes. Thus, for, example, the following displays just the number of words, in a file named file4:, wc -w file4, The following displays the number of characters in the, same file:, wc -m file4, As is generally the case with commands in Unix-like, operating systems, any combination of options can be, used together. For example, the following would count both, the numbers of lines and words in a file named file5:, wc -lw file5, Redirection can be used with wc to create more complex, commands. For example, the output from the above, command can be redirected using the standard output, redirection operator (which is designated by a rightward, pointing angle bracket) from the display screen to a file, named file6 with the following:, wc -lw file5 > file6, If file6 already exists, its contents will be overwritten; if it, does not exist, it will be created. The contents of file6 can, be easily confirmed with a text editor or with a command, such as cat, which is commonly used to read text files,, i.e.,, , grep [option(s)] pattern [file(s)], The items in square brackets are optional. When used, with no options and no arguments (i.e., input files), grep, searches standard input (which by default is text typed in, at the keyboard) for the specified pattern and returns each, line that contains a match to standard output (which by, default is the display screen)., A line of text is defined in this context not as what, appears as a line of text on the display screen but rather, as all text between two newline characters. Newline, characters are invisible characters that are represented in, Unix-like operating systems by a backslash followed by, the letter n and which are created when a user presses, the ENTER key when using a text editor (such as gedit)., Thus, a line of text returned by grep can be as short as a, single character or occupy many lines on the display, screen., grep can search any number of files simultaneously. Thus,, for example, the following would search the three files file1,, file2 and file3 for any line that contains thestring (i.e.,, sequence of characters) Lin:, grep Lin file1 file2 file3, Each result is displayed beginning on a separate line, and, it is preceded by the name of the file in which it was found, in the case of multiple files. The inclusion of the file names, in the output data can be suppressed by using the -h, option., grep is not limited to searching for just single strings. It, can also search for sequences of strings, including, phrases. This is accomplished by enclosing the sequence, of strings that forms the pattern in quotation marks (either, single or double). Thus, the above example could be, modified to search for the phrase Linux is:, grep 'Linux is' file1 file2 file3, Text searches with grep can be considerably broadened, by combining them with wildcards and/or performing, recursive searches. A wildcard is a character that can, represent some specific class of characters or sequence, of characters. The following is a modification of the above, example that uses the star wildcard (i.e., an asterisk),, which represents any character or sequence of characters,, to search all text files in the current directory (i.e., the, directory in which the user is currently working):, grep 'Linux is' *, , grep's search area can be broadened even further by using, its -r option to search recursively through an entire directory, tree (i.e., a directory and all levels of subdirectories within, it) rather than just the files within a specified directory. For, example, the following would search all files in the current, 91, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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directory and in all of its subdirectories (including their, subdirectories, etc.) for every line containing the full name, of the creator of Linux:, grep -r 'Linus Torvalds' *, One of the most commonly employed of grep's many, options is -i, which instructs it to ignore case, that is, to, ignore whether letters in the pattern and text searched are, lower case (i.e., small letters) or upper case (i.e., capital, letters). Thus, for instance, the previous example could, very easily be converted to a case-insensitive search as, follows:, grep -ir 'Linus Torvalds' *, This would produce the same results as, grep -ir 'linUS torvAlds' *, Another frequently used option is -c, which causes grep, to only report the number of times that the pattern has, been matched for each file and to not display the actual, lines. Thus, for instance, the following would show the, total number of times that the string inu appears in a file, named file4:, grep -c inu file4, Another useful option is -n, which causes grep to precede, each line of output with the number of the line in the text, file from which it was obtained. The -v option inverts the, match; that is, it matches only those lines that do not, contain the given pattern., The -w option tells grep to select only those lines that, contain an entire word or phrase that matches the, specified pattern. The -x option tells grep to select only, those lines that match exactly the specified pattern., The -l option tells grep to not return the lines containing, matches but to only return only the names of the files that, contain matches. The -L option is the opposite of the -l, option (and analogous to the -v option) in that it will cause, grep to return only the names of files that do not contain, the specified pattern., grep does not search the names of files for a specified, pattern, only the text contained within files. However,, sometimes it is useful to search the names of files, as, well as of directories and links, rather than the contents of, files. Fortunately, this can easily be accomplished by first, using the ls command to list the contents of a directory, and then using a pipe (which is represented by the vertical, bar character) to transfer its output to grep for searching., For example, the following would provide a list of all files,, directories and links in the current directory that contain, the string linu in their names:, ls | grep linu, The following example uses ls with its -l (i.e., long) option, (which is unrelated to grep's -l option) to find all filesystem, objects in the current directory whose permissions have, been set so that any user can read, write and execute, them:, ls -l | grep rwxrwxrwx, 92, , grep is very useful for obtain information from log and, configuration files. For example, it can be used to obtain, information about the USB (universal serial bus) devices, on a system by filtering the output from the dmesg, command (which provides the messages from the kernel, as a system is booting up) as follows:, dmesg | grep -i usb, Among grep's other options are --help, which provides a, very compact summary of some of its many capabilities,, and -V, or --version, which provides information about the, currently installed version., grep's search functionality can be even further refined, through the use of regular expressions. These are a pattern, matching system that uses strings constructed according, to pre-defined syntax rules to find desired patterns in text., Additional information about grep, including its use with, regular expressions, can be obtained from its built-in, manual page by using the man command, i.e.,, man grep, The name grep comes from a command in ed, which was, the original text editor on the UNIX operating system. The, command takes the form g/re/p, which means to search, globally for matches to the regular expression (i.e., re),, and print (which is UNIX terminology for write on the display, screen) lines that are found., ln command, ln command is used to create links. Links are a kind of, shortcuts to other files. The general form of command is:, $ ln TARGET LINK_NAME, There are two types of links, soft links and hard links. By, default, hard links are created. If you want to create soft, link, use -s option. In this example, both types of links are, created for the file usrlisting., $ ln usrlisting hard_link, $ ln -s usrlisting soft_link, $ ls -l, total 12, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 hard_link, lrwxrwxrwx 1 raghu raghu 10 2012-07-09 14:00 soft_link > usrlisting, -rw-r--r-- 1 raghu raghu 491 2012-07-06 16:02 usrcopy, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 usrlisting, Some additional useful commands, alias command, 'alias' is another name for a command. If no argument is, given, it shows current aliases. Aliases can be used for, short names of commands. For example, you might use, clear command frequently. You can create an alias for it:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ alias c="clear", Next time enter c on command line, your screen will be, clear. Current aliases can be checked with 'alias', command:, $ alias, alias alert='notify-send --urgency=low -i "$([ $? = 0 ] &&, echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/, ^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"', alias c='clear', alias egrep='egrep --color=auto', alias fgrep='fgrep --color=auto', alias grep='grep --color=auto', alias l='ls -CF', alias la='ls -A', alias ll='ls -alF', alias ls='ls --color=auto', w command, The w command shows who is logged in to the system, and what they are doing., A login, logging in or logging on is the entering of identifier, information into a system by a user in order to access, that system (e.g., a computer or a website). It generally, requires the user to enter two pieces of information, first a, user name and then a password., The basic syntax of w is:, w [options] [username1, username2, . . .], The square brackets indicated that the enclosed items, are optional. When used without any options, w sends to, standard output (which is by default the display screen) a, header line followed by a table that contains a line of data, for each user currently logged in., The header shows six items: the current time, how long, the system has been running (in minutes) since it was, booted up (i.e., started up), how many users are currently, logged on, and the system load averages, i.e., the average, number of processes active, during the last one, five and, 15 minutes. A process is an executing(i.e., running), instance of a program., The main part of w's output consists of a table showing, eight items of information for each user currently logged, into the system. The eight columns are labeled USER,, TTY, FROM, LOGIN@, IDLE, JCPU, PCPU and WHAT., USER is the login name of the user. TTY (which now, stands for terminal type but originally stood for teletype), is the name of the console or terminal (i.e., combination, of monitor and keyboard) that the user logged into, which, can also be found by using the tty command. Every time, a user logs in across the network, a new tty is assigned, to that user., , independent logical consoles that run in separate login, sessions, but which are accessed from the same physical, console (i.e., the same keyboard and screen). That is,, each virtual console can have a different, or the same,, user logged into it. On a Red Hat system, seven virtual, consoles are configured and active by default., FROM is the remote host (i.e., the name of some other, computer), if any, that the user logged into. LOGIN@ is, the time at which the user logged in. IDLE is the number, of hours and minutes since the user last typed anything, at the keyboard., JCPU is the number of minutes accumulated by all, processes attached to the tty. It does not include past, background processes (i.e., low priority processes that, operate only in gaps between higher priority foreground, processes), but it does include currently running, background processes., PCPU is the time consumed by the current process,, named in the WHAT column. WHAT lists the name of the, current process along with any options and arguments(i.e.,, input files) used with the command that launched it., Among the more useful of w's few options is -h, which, tells it to omit the header header line from its output. The, -s option tells it to use the short format, which omits the, login time, JCPU and PCPU columns. The -l option creates, a long listing, which is the same as the default. The -V, option displays the version number of the currently installed, w program., By default, w reports on all users. However, it can be made, to report on only a specified set of users by providing those, usernames in a comma-separated list., w provides information similar to that which would be, provided by a combination of the uptime, who and ps -a, commands. uptime produces a single line of output that, is the same as w's header line. who shows who is currently, logged into the system. ps -a lists all processes with a tty, except session leaders (i.e., processes that created, sessions)., w can be useful, but there are some faults with the, information it provides, and thus its output should only be, considered approximate. In particular, the notion of, thecurrent process is unclear and there are some problems, detecting background processes, even though they usually, account for much of the load on the system. Also, the, CPU time is only an estimate; for example, if a user leaves, a background process running after logging out, the time, is credited to the person currently on that terminal., last command, Display information about the users who logged in and out, of the system. The output of last can be very large, so the, following output has been filtered (through head) to display, top 10 lines only:, , The consoles can be real or virtual. A feature of Linux, systems is the use of virtual consoles, which act as, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 93
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$ last | head, root tty1 Mon Jul 9 10:06 still logged in, root tty1 Mon Jul 9 10:06 - 10:06 (00:00), raghu pts/1 :0.0 Mon Jul 9 10:05 - 10:06 (00:00), raghu pts/0 :0.0 Mon Jul 9 09:34 still logged in, raghu tty7 :0 Mon Jul 9 09:19 still logged in, , /dev/sda2 209715196 196519248 13195948 94%/, media/Data, fdisk command, The fdisk is the tool for getting partition information, adding, and removing partitions.The fdisk tool requires super user, privileges. To list all the partitions of all the hard drives, available:, $ fdisk -l, , reboot system boot 2.6.38-13-generi Mon Jul 9 09:09 10:12 (01:02), , Disk /dev/sda: 320.1 GB, 320072933376 bytes, , raghu tty7 :0 Sun Jul 8 23:36 - 00:30 (00:54), , 255 heads, 63 sectors/track, 38913 cylinders, , reboot system boot 2.6.38-13-generi Sun Jul 8 23:36 00:30 (00:54), , Units = cylinders of 16065 * 512 = 8225280 bytes, , raghu tty7 :0 Sun Jul 8 21:07 - down (01:06), reboot system boot 2.6.38-13-generi Sun Jul 8 21:07 22:14 (01:07), A similar command is lastb that shows last bad login, attempts. But this command must be run as root otherwise, would get an error of permission denied, $ lastb, raghu tty2 Mon Jul 9 10:16 - 10:16 (00:00), UNKNOWN tty2 Mon Jul 9 10:15 - 10:15 (00:00), ubuntu tty8 :1 Mon Jul 2 10:23 - 10:23 (00:00), btmp begins Mon Jul 2 10:23:54 2012, du command, du command determines disk usage of a file. If the, argument given to it is a directory, then it will list disk, usage of all the files and directories recursively under that, directory:, $ du /etc/passwd, 4 /etc/passwd, , Sector size (logical/physical): 512 bytes / 512 bytes, I/O size (minimum/optimal): 512 bytes / 512 bytes, Disk identifier: 0x396f396f, Device Boot Start End Blocks Id System, /dev/sda1 1 2611 20971520 7 HPFS/NTFS, /dev/sda2 2611 28720 209715200 7 HPFS/NTFS, /dev/sda3 * 28720 38914 81882113 5 Extended, /dev/sda5 28720 33942 41943040 7 HPFS/NTFS, /dev/sda6 33942 34464 4194304 7 HPFS/NTFS, /dev/sda7 34464 35739 10240000 83 Linux, /dev/sda8 35739 36376 5120000 83 Linux, /dev/sda9 36376 36886 4096000 82 Linux swap / Solaris, /dev/sda10 36887 38276 11164672 83 Linux, /dev/sda11 38277 38914 5117952 83 Linux, fdisk is an interactive tool to edit the partition table. It, takes a device (hard disk) as an argument, whose partition, table needs to be edited., $ fdisk /dev/sda, , $ du hello/, 4 hello/orb.db/logs, , WARNING: DOS-compatible mode is deprecated. It's, strongly recommended to switch off the mode (command, 'c') and change display units to sectors (command 'u')., , 20 hello/orb.db, , Command (m for help): m, , 52 hello/HelloApp, , 108 hello/, , Command, , action, , df command, , a, , toggle a bootable flag, , df reports file system usage. For example:, , b, , edit bsd disk label, , c, , toggle the dos compatibility flag, , Filesystem 1K-blocks Used Available Use% Mounted on, , d, , delete a partition, , /dev/sda7 10079084 7372872 2194212 78% /, , l, , list known partition types, , none 1522384 768 1521616 1% /dev, , m, , print this menu, , $ df, , none 1529012 252 1528760 1% /dev/shm, , n, , add a new partition, , none 1529012 108 1528904 1% /var/run, , o, , create a new empty DOS partition table, , none 1529012 4 1529008 1% /var/lock, , p, , print the partition table, , /dev/sda8 5039616 3758824 1024792 79% /home, , q, , quit without saving changes, , 94, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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s, , create a new empty Sun disklabel, , t, , change a partition's system id, , u, , change display/entry units, , v, , verify the partition table, , w, , write table to disk and exit, , x, , extra functionality (experts only), , Pressing 'm' at the fdisk prompt prints out above help that, lists all the commands available for fdisk. A new, partition can be created with n and an existing partition, can be deleted with d command. When you are done editing, the partitions, press w to write the changes to the disk,, and finally, q to quit from fdisk (q dies not save changes)., netstat command, 'netstat' is the command used to check the network, statistics of the system. It will list the current network, connections, routing table information, interface, statistics, masquerade connections and a lot more, information., $ netstat | head, Active Internet connections (w/o servers), Proto Recv-Q Send-Q Local Address Foreign Address State, Active UNIX domain sockets (w/o servers), Proto RefCnt Flags Type State I-Node Path, unix 13 [ ] DGRAM 8498 /dev/log, unix 2 [ ] DGRAM 6824 @/org/kernel/udev/udevd, unix 3 [ ] STREAM CONNECTED 56738 /var/run/dbus/, system_bus_socket, unix 3 [ ] STREAM CONNECTED 56113, , All of the files on a system have permissions that allow or, prevent others from viewing, modifying or executing. If the, file is of type Directory then it restricts different actions, than files and device nodes. The super user "root" has the, ability to access any file on the system. Each file has, access restrictions with permissions, user restrictions with, owner/group association. Permissions are referred to as, bits., If the owner read & execute bit are on, then the permissions, are:, There are three types of access restrictions:, Permission, , (view), , r or 4, , write, , (edit), , w or 2, , execute, , passwd command, Change your password with 'passwd' command., shutdown -h now, Finally shut down your system using this command., Understanding and using file permissions, In Linux and Unix, everything is a file. Directories are files,, files are files and devices are files. Devices are, usually referred to as a node; however, they are still files., , (execute), , x or 1, , There are also three types of user restrictions:, User, , ls output, , owner, , -rwx------, , group, , ----rwx---, , other, , -------rwx, , The restriction type scope is not inheritable:, the file owner will be unaffected by restrictions, set for his group or everybody else., Folder/Directory Permissions, Directories have directory permissions. The directory, permissions restrict different actions than with files or device, nodes., Permission, , Action, , chmod option, , Read, , (view contents,, i.e. ls command), , r or 4, , Write, , (create or remove, files from dir), , w or 2, , execute, , (cd into directory), , x or 1, , history command, This command shows the commands you have entered, on your terminal so far., , Chmod option, , read, , unix 3 [ ] STREAM CONNECTED 29138, unix 3 [ ] STREAM CONNECTED 29137, , Action, , 1. read restricts or allows viewing the directories contents,, i.e. ls command, 2. write restricts or allows creating new files or deleting, files in the directory. (Caution: write access for a, directory allows deleting of files in the directory even if, the user does not have write permissions for the file!), 3. execute restricts or allows changing into the directory,, i.e. cd command, Folders (directories) must have 'execute' permissions set, (x or 1), or folders (directories) will NOT FUNCTION as, folders (directories) and WILL DISAPPEAR from view in, the file browser (Nautilus)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 95
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Permissions in Action, , Here are a few examples of chmod usage with letters (try, these out on your system)., , $ ls -l /etc/hosts, -rw-r--r-- 1 root root 288 2005-11-13 19:24 /etc/hosts, Using the example above we have the file "/etc/hosts", which is owned by the user root and belongs to the root, group., The permissions from the above /etc/hosts ls output, -rw-r--r-owner = Read & Write (rw-), group = Read (r--), , First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, total 0, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, , other = Read (r--), , Add owner execute bit:, , Changing permissions, The command to use when modifying permissions is, chmod. There are two ways to modify permissions, with, numbers or with letters. Using letters is easier to, understand for most people. When modifying permissions, be careful not to create security problems. Some files are, configured to have very restrictive permissions to prevent, unauthorized access. For example, the /etc/shadow file, (file that stores all local user passwords) does not have, permissions for regular users to read or otherwise access., $ ls -l /etc/shadow, , $ chmod u+x file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod o+wx file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, , -rw-r----- 1 root shadow 869 2005-11-08 13:16 /etc/shadow, , $ chmod g-r file3, , Permissions:, , $ ls -l file3, , owner = Read & Write (rw-), , Add read, write and execute to everyone:, , group = Read (r--), , $ chmod ugo+rwx file4, , other = None (---), , $ ls -l file4, , Ownership:, owner = root, , -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, , group = shadow, , $, chmod with Numbers, , chmod with Letters, Usage: chmod {options} filename, Options, , 96, , -rw----r-- 1 user user 0 Nov 19 20:13 file3, , Definition, , U, , owner, , G, , group, , O, , other, , A, , all (same as ugo), , X, , execute, , W, , write, , R, , read, , +, , add permission, , -, , remove permission, , =, , set permission, , Usage: chmod {options} filename, Options, , Definition, , #--, , owner, , -#-, , group, , --#, , other, , 1, , execute, , 2, , write, , 4, , read, , Owner, Group and Other is represented by three numbers., To get the value for the options determine the type of, access needed for the file then add., For example if need a file that has -rw-rw-rwx permissions, will use the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Owner, read & write, , Group, read & write, , 4+2=6, , Other, read, write & execute, , 4+2=6, , 4+2+1=7, , Another example if you want a file that has --w-r-x--x, permissions you will use the following:, , write, 2, , Group, read & execute, 4+1 = 5, , Other, execute, 1, , $ chmod 251 filename, Here are a few examples of chmod usage with numbers, (try these out on your system)., First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, Add owner execute bit:, $ chmod 744 file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod 647 file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, $ chmod 604 file3, $ ls -l file3, -rw----r-- 1 user user 0 Nov 19 20:13 file3, Add read, write and execute to everyone:, $ chmod 777 file4, $ ls -l file4, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, chmod with sudo, , -rw-r--r-- 1 root root 550 2005-11-13 19:45 /usr/local/bin/, somefile, $ sudo chmod o+x /usr/local/bin/somefile, $ ls -l /usr/local/bin/somefile, -rw-r--r-x 1 root root 550 2005-11-13 19:45 /usr/local/, bin/somefile, $, Recursive permission changes, To change the permissions of multiple files and directories, with one command. Please note the warning in the chmod, with sudo section and the Warning with Recursive chmod, section., Recursive chmod with -R and sudo, To change all the permissions of each file and folder under, a specified directory at once, use sudo chmod with -R, $ sudo chmod 777 -R /path/to/someDirectory, , total 0, , $, , $ ls -l /usr/local/bin/somefile, , $, , $ chmod 667 filename, , Owner, , Please be careful when using sudo!), , $ ls -l, total 3, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file2, Recursive chmod using find, pipemill, and sudo, To assign reasonably secure permissions to files and, folders/directories, it's common to give files a permission, of 644, and directories a 755 permission, since chmod -R, assigns to both. Use sudo, the find command, and a, pipemill to chmod as in the following examples., To change permission of only files under a specified, directory., $ sudo find /path/to/someDirectory -type f -print0 | xargs, -0 sudo chmod 644, user@host:/home/user$ ls -l, total 3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, To change permission of only directories under a specified, directory (including that directory):, $ sudo find /path/to/someDirectory -type d -print0 | xargs, -0 sudo chmod 755, $ ls -l, , total 3, Changing permissions on files that do not have ownership, of: (Note that changing permissions the wrong way on the, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, wrong files can quickly mess up the system a great deal!, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 97
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drwxr-xr-x 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, Warning with Recursive chmod, WARNING: Although it's been said, it's worth mentioning, in context of a gotcha typo. Please note, Recursively, deleting or chown-ing files are extremely dangerous. You, will not be the first, nor the last, person to add one too, many spaces into the command. This example will hose, your system:, $ sudo chmod -R / home/john/Desktop/tempfiles, Note the space between the first / and home.You have, been warned., Changing the file owner and group, A file's owner can be changed using the chown command., For example, to change the foobar file's owner to tux:, $ sudo chown tux foobar, To change the foobar file's group to penguins, you could, use either chgrp or chown with special syntax:, $ sudo chgrp penguins foobar, $ sudo chown :penguins foobar, Finally, to change the foobar file's owner to tux and the, group to penguins with a single command, the syntax, would be:, $ sudo chown tux:penguins foobar, Note that, by default, you must use sudo to change a, file's owner or group., Difference between chown and chgrp, 1) Chown command is used to change ownership as well, as group name associated to different one, where as, chgrp can change only group associated to it., 2) Many people say that regular user only able to use, chgrp to change the group if the user belongs to them., But it's not true a user can use chown and chgrp, irrespective to change group to one of their group, because chown is located in /bin folder so every can, use it with some limited access., umask - Set default permissions, The umask command controls the default permissions, given to a file when it is created., It uses octal notation to express a mask of bits to be, removed from a file's mode attributes., [me@linuxbox ~]$ rm -f foo.txt, [me@linuxbox ~]$ umask, 0002, [me@linuxbox ~]$ > foo.txt, [me@linuxbox ~]$ ls -l foo.txt, -rw-rw-r-- 1 me me 0 2008-03-06 14:53 foo.txt, , we ran the umask command without an argument to see, the current value. It responded with the value 0002 (the, value 0022 is another common default value), which is the, octal representation of our mask. We next create a new, instance of the file foo.txt and observe its permissions., We can see that both the owner and group both get read, and write permission, while everyone else only gets read, permission. The reason that world does not have write, permission is because of the value of the mask., $ rm foo.txt, $ umask 0000, $ > foo.txt, $ ls -l foo.txt, -rw-rw-rw- 1 me me 0 2008-03-06 14:58 foo.txt, When we set the mask to 0000 (effectively turning it off),, we see that the file is now, world writable. To understand how this works, we have to, look at octal numbers again., If we take the mask and expand it into binary, then compare, it to the attributes., Original file mode, , --- rw- rw- rw-, , Mask, , 000 000 000 010, , Result, , --- rw- rw- r--, , Ignore for the moment the leading zeros (we'll get to those, in a minute) and observe that, where the 1 appears in our mask, an attribute was removedin this case, the the world, write permission. That's what the mask does. Everywhere, a 1 appears in the binary value, of the mask, an attribute is unset. If we look at a mask, value of 0022, we can see what it does:, Original file mode, , --- rw- rw- rw-, , Mask 000 000 010 010, Result, , --- rw- r-- r--, , Again, where a 1 appears in the binary value, the, corresponding attribute is unset. Play with some values, (try some sevens) to get used to how this works. When, you're done, remember to clean up:, $ rm foo.txt; umask 0002, The Tar command, The tar (i.e., tape archive) command is used to convert a, group of files into an archive., An archive is a single file that contains any number of, individual files plus information to allow them to be, restored to their original form by one or more extraction, programs. Archives are convenient for storing files as well, as for for transmitting data and distributing programs., Moreover, they are very easy to work with, often much, more so than dealing with large numbers of individual files., , We first removed any old copy of foo.txt to make sure we, were starting fresh. Next,, 98, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Although tar was originally designed for backups on, magnetic tape, it can now be used to create archive files, anywhere on a file system. Archives that have been created, with tar are commonly referred to as tar balls., Unlike some other archiving programs, and consistent with, the Unix philosophy that each individual program should, be designed to do only one thing but do it well, tar does, not perform compression. However, it is very easy to, compress archives created with tar by using specialized, compression utilities., tar's basic syntax is, tar option(s) archive_name file_name(s), tar has numerous options, many of which are not, frequently used. Unlike many commands, tar requires the, use of at least one option, and usually two or more are, necessary., tar files are created by using both the -c and -f options., The former instructs tar to create an archive and the latter, indicates that the next argument (i.e., piece of input data, in a command) will be the name of the new archive file., Thus, for example, the following would create an archive, file called file.tar from the three files namedfile1, file2 and, file3 that are located in the current directory (i.e., the, directory in which the user is currently working):, tar -cf file.tar file1 file2 file3, It is not absolutely necessary that the new file have the, .tar extension; however, the use of this extension can be, is very convenient because it allows the type of file to be, visually identified. It is necessary, however, that the -f option, be the final option in a sequence of contiguous, singleletter options; otherwise, the system will become confused, as to the desired name for the new file and will use the, next option in the sequence as the name., The -v (i.e., verbose) option is commonly used together, with the -c and -f options in order to display a list of the, files that are included in the archive. In such case, the, above example would become, tar -cvf file.tar file1 file2 file3, tar can also be used to make archives from the contents, of one or more directories. The result is recursive; that is,, it includes all objects (e.g., directories and files) within, each level of directories. For example, the contents of two, directories named dir1 and dir2 could be archived into a, file named dir.tar with the following:, tar -cvf dir.tar dir1 dir2, It is often convenient to use tar with a wildcard (i.e., a, character which can represent some specific class of, characters or sequence of characters). The following, example uses the star wildcard (i.e., an asterisk), which, represents any character or sequence of characters, to, create an archive of every object in the current directory:, tar -cf *, By default, tar creates an archive of copies of the original, files and/or directories, and the originals are retained., , However, they can be removed when using tar by adding, the --remove-files option., As it has no compression and decompression capabilities, of its own, tar is commonly used in combination with an, external compression utility. A very handy feature of the, GNU version (which is standard on Linux) is the availability, of options that will cause standard compression programs, to compress a new archive file as soon as it has been, created. They are -j (for bzip2), -z (for gzip) and -Z (for, compress). Thus, for example, the following would create, an archive named files.tar.bz2 of the files file4, file5 and, file6 that is compressed using bzip2:, tar -cvjf files.tar.bz2 file4 file5 file6, tar can also be used for unpacking tar files. However, before, doing this, there are several steps that should be taken., One is to confirm that sufficient space is available on the, hard disk drive (HDD). Another is to move to an empty, directory (which usually involves creating one with an, appropriate name) to prevent the reconstituted files from, cluttering up the current directory and overwriting any files, or directories with same names that are in it. In addition, if, the archive has been compressed, it must first be, decompressed using the appropriate decompression, program (which can usually be determined by the filename, extension)., In order to unpack a tar file, the -x (for extract) and -f, options are required. It is also common to add the -v option, to provide a running listing of the files being unpacked., Thus, for example, to unpack the archive file.tar created in, a previous example the following would be used:, tar -xvf file.tar, Just as options are available to allow three compression, programs to automatically compress newly created tar, files, the same options can be used to have the, compression programs automatically decompress tar files, prior to extraction. Thus, for instance, the following would, decompress and extract the contents of the compressed, archive files.tar.bz2 that was created in an above example:, tar -xjvf files.tar.bz2, Files can be added to an existing archive using the -r, option. As is always the case with tar, it is also necessary, to use the -f option to indicate that the followingstring (i.e.,, sequence of characters) is the name of the archive. For, example, the following would append a file named file7 to, file.tar:, tar -rf file.tar file7, The --delete option allows specified files to be completely, removed from a tar file (except when the tar file is on, magnetic tape). However, this is different from an, extraction, as copies of the removed files are not made, and placed in the current directory. Thus, for example, the, files file1 and file2 can be removed from file.tar with the, following:, tar -f file.tar --delete file1 file2, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 99
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The -t option tells tar to list the contents of an, uncompressed archive without performing an extraction., Thus, the following would list the contents of file.tar:, tar -tf file.tar, Input, output and error redirection in linux, Input/output redirection means the text that is showing on, the screen while you are running any command(program)in, the shell, that information can be redirect elsewhere and, even it can store this output in a file or can be print directly., This function called Redirection, and can also redirect the, input of program., In Linux systems everything consider as a file., A file descriptor is number that is associated with every, file, When run a program in shell ( i.e when execute a command, ) on the back end Linux access 3 special files., Standard input - 0 file descriptor( example = mouse,), Standard output - 1 file descriptor( example = Screen), Standard error output - 2 file descriptor(example=Screen), So it can redirect these files to other files. If user redirect, standard output (Descriptor = 1) to the printer, instead of, showing these outputs on the screen and the computer, start getting print on paper., Output Redirection, Output Redirection is most commonly used, when execute, a command it's normally appears on the terminal . If extract, any tar file you will notice all the output scrolls down rapidly., And can redirect this output in a file for inspecting the, output or can send anybody via email. This is called Output, Redirection. Using this operator '>' in shell can redirect, the output in a file., Example :, $ ls > output.txt, $ cat output.txt, bin, boot, , root, sbin, selinux, srv, sys, tmp, usr, var, $, If output.txt file is already exit then '>' operator, will overwrite the file for append more output, into output.txt use '>>' instead of '>'., Input Redirection, You can redirect your input by using '<' operator. Cannot, run input redirection on all programs or commands. And, can use only with that programs or commands that accept, Input from keyboard., Example : user going to send an email and already have, Template of that email. and can put template in the email, body using input redirect., $ mail ali < mail_template.txt, above command launch email program with, mail_template.txt contents., Now due to advancement in GUI, and also lots of good, email clients, method is rarely used., Error Redirection, Error Redirection is very helpful when in trouble. In this, case user trying to open a file that is not readable for my, user will get permission denied errors. it will redirect these, error into error.txt file., Example :, $ cat ali.txt 2> /home/H.Ali/error.txt, $ cat /home/H.Ali/error.txt, cat: ali.txt: Permission denied, , etc, , In the above command 2 is descriptor of error redirection, file by typing '2>' you are saying redirect any kind of error, to the file error.txt, , home, , Pipes ' | ' in Linux, , lib, , Linux pipes allow us connect output stream of 'command, a' to input stream of 'command b'. here in my case i will, pipe cat commands output into less as input., , dev, , lib64, lost+found, media, mnt, opt, output.txt, proc, 100, , Example : cat /var/log/messages | less, we can also use pipe for searching strings specially from, large text files., cat /var/log/messages | grep kernal | less, grep is a line searcher it will search lines for specific piece, of text., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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above command will shearch a keywork 'kernel' with grep, and then pipe it again to less., Pipes in linux, A pipe is a form of redirection that is used in Linux and, other Unix-like operating systems to send the output of, one program to another program for further processing., Redirection is the transferring of standard output to some, other destination, such as another program, a file or a, printer, instead of the display monitor (which is its default, destination). Standard output, sometimes abbreviated, stdout, is the destination of the output from command line, (i.e., all-text mode) programs in Unix-like operating, systems., Pipes are used to create what can be visualized as a, pipeline of commands, which is a temporary direct, connection between two or more simple programs. This, connection makes possible the performance of some highly, specialized task that none of the constituent programs, could perform by themselves. A command is merely an, instruction provided by a user telling a computer to do, something, such as launch a program. The command line, programs that do the further processing are referred to as, filters., This direct connection between programs allows them to, operate simultaneously and permits data to be transferred, between them continuously rather than having to pass it, through temporary text files or through the display screen, and having to wait for one program to be completed before, the next program begins., Examples, A pipe is designated in commands by the vertical bar, character, which is located on the same key as the, backslash on U.S. keyboards. The general syntax for, pipes is:, command_1 | command_2 [| command_3 . . . ], This chain can continue for any number of commands or, programs., A very simple example of the benefits of piping is provided, by the dmesg command, which repeats the startup, messages that scroll through the console(i.e., the all-text,, full-screen display) while Linux is booting (i.e., starting, up). dmesg by itself produces far too many lines of output, to fit into a single screen; thus, its output scrolls down the, screen at high speed and only the final screenful of, messages is easily readable. However, by piping the output, of dmesg to the filter less, the startup messages can, conveniently be viewed one screenful at a time, i.e.,, dmesg | less, , The same result could be achieved by first redirecting the, output of dmesg to a temporary file and then displaying, the contents of that file on the monitor. For example, the, following set of two commands uses the output redirection, operator (designated by a rightward facing angle bracket), to first send the output of dmesg to a text file called tempfile1, (which will be created by the output redirection operator if, it does not already exist), and then it uses another output, redirection operator to transfer the output of tempfile1 to, the display screen:, dmesg > tempfile1, tempfile1 > less, However, redirection to a file as an intermediate step is, clearly less efficient, both because two separate, commands are required and because the second, command must await the completion of the first command, before it can begin., The use of two pipes to chain three commands together, could make the above example even more convenient for, some situations. For example, the output of dmesg could, first be piped to the sort filter to arrange it into alphabetic, order before piping it to less:, dmesg | sort -f | less, The -f option tells sort to disregard case (i.e., whether, letters are lower case or upper case) while sorting., Likewise, the output of the ls command (which is used to, list the contents of a directory) is commonly piped to the, the less (or more) command to make the output easier to, read, i.e.,, ls -al | less, or, ls -al | more, ls reports the contents of the current directory (i.e., the, directory in which the user is currently working) in the, absence of any arguments (i.e., input data in the form of, the names of files or directories). The -l option tells ls to, provide detailed information about each item, and the aoption tells ls to include all files, including hidden files, (i.e., files that are normally not visible to users). Because, ls returns its output in alphabetic order by default, it is not, necessary to pipe its output to the sort command (unless, it is desired to perform a different type of sorting, such as, reverse sorting, in which case sort's -r option would be, used)., This could just as easily be done for any other directory., For example, the following would list the contents of the /, bin directory (which contains user commands) in a, convenient paged format:, , less allows the output of dmesg to be moved forward one, ls -al /bin | less, screenful at a time by pressing the SPACE bar and back, The following example employs a pipe to combine the ls, one screenful at a time by pressing the b key. The command, and the wc (i.e., word count) commands in order to show, can be terminated by pressing the q key. (The more, how many filesystem objects (i.e., files, directories and, command could have been used here instead of less;, links) are in the current directory:, however, less is newer than more and has additional, functions, including the ability to return to previous pages, ls | wc -l, of the output.), 101, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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ls lists each object, one per line, and this list is then piped, to wc, which, when used with its -l option, counts the, number of lines and writes the result to standard output, (which, as usual, is by default the display screen)., The output from a pipeline of commands can be just as, easily redirected to a file (where it is written to that file) or, a printer (where it is printed on paper). In the case of the, above example, the output could be redirected to a file, named, for instance, count.txt:, ls | wc -l > count.txt, The output redirection operator will create count.txt if it, does not exist or overwrite it if it already exists. (The file, does not, of course, require the .txt extension, and it could, have just as easily been named count, lines or anything, else.), The following is a slightly more complex example of, combining a pipe with redirection to a file:, echo -e "orange \npeach \ncherry" | sort > fruit, The echo command tells the computer to send the text, that follows it to standard output, and its -e option tells the, computer to interpret each \nas the newline symbol (which, is used to start a new line in the output). The pipe redirects, the output from echo -e to the sort command, which, arranges it alphabetically, after which it is redirected by, the output redirection operator to the file fruit., As a final example, and to further illustrate the great power, and flexibility that pipes can provide, the following uses, three pipes to search the contents of all of the files in, current directory and display the total number of lines in, them that contain the string Linux but not the stringUNIX:, cat * | grep "Linux" | grep -v "UNIX" | wc -l, In the first of the four segments of this pipeline, the cat, command, which is used to read and concatenate (i.e.,, string together) the contents of files, concatenates the, contents of all of the files in the current directory. The, asterisk is a wildcard that represents all items in a specified, directory, and in this case it serves as an argument to cat, to represent all objects in the current directory., The first pipe sends the output of cat to the grep, command, which is used to search text. The Linux, argument tells grep to return only those lines that contain, the string Linux. The second pipe sends these lines to, another instance of grep, which, in turn, with its -v option,, eliminates those lines that contain the string UNIX., Finally, the third pipe sends this output to wc -l, which, counts the number of lines and writes the result to the, display screen., Find hardware devices in Ubuntu Linux with lshw, There are a variety of ways to find out what kind of, hardware running in linux, but one of the easiest ways, that gives a large amounts of valuable data is to use lshw, (Hardware Lister). And lshw is installed by default., Testing of lshw command as shown below…, $ sudo lshw, 102, , Installing, lshw is available on most package management systems., If use APT (Debian-based distros: Ubuntu, Linux Mint, and, others), run the following command in terminal:, $ sudo apt-get install lshw, If use Yum (Red Hat, Fedora, CentOS, Yellow Dog Linux,, etc), run the following command in terminal:, $ sudo yum install lshw, If these instructions don't match your package manager,, look for specific instructions on the lshw site to get it, installed on your system., Using lshw, If you just run lshw by itself on the command line, your, screen will be flooded with large amounts of text., Fortunately, it is very easy to get lshw to give you output, that meets your needs., Shorter output, If you just quickly want to quickly find the chipset version, of a piece of hardware is, you can run the following to, provide a very short output that should give you what you, need:, $ sudo lshw -short, For example, here is a sample when I run this on my Dell, Studio 17 laptop (Note: I've removed a large portion of the, output to make this fit):, $ sudo lshw -short, Device class, , Description, , system, , Studio 1735, , bus, , 0H275K, , memory, , 64KiB BIOS, , processor, , Intel(R) Core(TM)2 Duo CPU, T8100 @ 2.10GHz, , memory, , 32KiB L1 cache, , memory, , 3MiB L2 cache, , memory, , 4GiB System Memory, , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , display, , Mobility Radeon HD 3650, , multimedia, , RV635 Audio device [Radeon HD, 3600 Series], , multimedia, , 82801H (ICH8 Family) HD, Audio Controller, , eth1 network, , BCM4322 802.11a/b/g/n, Wireless LAN Controller, , eth0 network, , NetLink BCM5784M Gigabit, Ethernet PCIe, , /dev/sda disk, 250GB WDC WD2500BEVS-7, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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This of course leaves out a lot of detail. Maybe we just, need to store the data somewhere so it's easier to work, with., Storing output to a file, If you'd like to put all the lshw output into a file, you can do, so easily from the terminal with output redirection., $ sudo lshw > hardware.txt, This will run the lshw command and put all the output into, a file in the current directory called hardware.txt. Note, that this will replace any file in the current directory called, hardware.txt. Make sure that you either backup the file,, give the output file a unique name, or are prepared to lose, that original file's information., Now you can open the hardware.txt file with your favorite, editor and look through the informations., , Creating HTML or XML Output, lshw has the ability to format its output in either HTML or, XML. This can be very helpful if you want to post your, hardware specs somewhere online to be viewed or to send, the data to a storage system., To create HTML output, simply give lshw the -html, option:, $ sudo lshw -html > hardware.html, This will format the output into a HTML document and, save the output in a file called hardware.html., Creating XML is done with the -xml option:, $ sudo lshw -xml > hardware.xml, Like before, this will output the document in XML format, and save it to hardware.xml., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 103
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Date command examples to display and set, system date time, Date command is helpful to display date in several formats., It also allows you to set systems date and time., Here few examples on how to use date command with, practical examples., When execute date command without any option, it will, display the current date and time as shown below., $ date, Mon May 20 22:02:24 PDT 2013, 1. Display Date from a String Value using -date, Option, If you have a static date or time value in a string, you can, use -d or -date option to convert the input string into date, format as shown below., Please note that this doesn't use the current date and, time value. Instead is uses the date and time value that, you pass as string., The following examples takes an input date only string,, and displays the output in date format. If you don't specify, time, it uses 00:00:00 for time., $ date --date="12/2/2014", Tue Dec 2 00:00:00 PST 2014, , 3. Get Relative Date Using -date option, You can also use date command to get a future date using, relative values., For example, the following examples gets date of next, Monday., $ date --date="next mon", Mon May 27 00:00:00 PDT 2013, If string=@is given to date command, then date command, convert seconds since the epoch (1970-01-01 UTC) to a, date., It displays date in which 5 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@5, Wed Dec 31 16:00:05 PST 1969, It displays date in which 10 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@10, Wed Dec 31 16:00:10 PST 1969, It displays date in which 1 minute (i.e. 60 seconds) is, elapsed since epoch 1970-01-01 UTC:, $ date --date=@60, Wed Dec 31 16:01:00 PST 1969, , $ date --date="2 Feb 2014", , 4. Display past date, , Sun Feb 2 00:00:00 PST 2014, , You can display a past date using the -date command., Few possibilities are shown below., , $ date --date="Feb 2 2014", Sun Feb 2 00:00:00 PST 2014, The following example takes an input date and time string,, and displays the output in date format., , $ date --date='3 seconds ago', Mon May 20 21:59:20 PDT 2013, $ date --date="1 day ago", , $ date --date="Feb 2 2014 13:12:10", , Sun May 19 21:59:36 PDT 2013, , Sun Feb 2 13:12:10 PST 2014, , $ date --date="yesterday", , 2. Read Date Patterns from a file using -file option, This is similar to the -d or -date option that we discussed, above. But, you can do it for multiple date strings. If you, have a file that contains various static date strings, you, can use -f or -file option as shown below., In this example, we can see that datefile contained 2 date, strings. Each line of datefile is parsed by date command, and date is outputted for each line., $ cat datefile, , $ date --date="1 month ago", Sat Apr 20 21:59:58 PDT 2013, $ date --date="1 year ago", Sun May 20 22:00:09 PDT 2012, 5. Set Date and Time using -set option, You can set date and time of your system using -s or -set, option as shown below.., , Sept 9 1986, Aug 23 1987, , In this example, initially it displayed the time as 20:09:31., We then used date command to change it to 21:00:00., , $ date --file=datefile, Tue Sep 9 00:00:00 PDT 1986, Sun Aug 23 00:00:00 PDT 1987, , 104, , Sun May 19 22:00:26 PDT 2013, , $ date, Sun May 20 20:09:31 PDT 2013, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ date -s "Sun May 20 21:00:00 PDT 2013", Sun May 20 21:00:00 PDT 2013, $ date, , The timestamp of datefile is changed using touch command. This was done few seconds after the above date, command's output., $ touch datefile, , Sun May 20 21:00:05 PDT 2013, 6. Display Universal Time using -u option, You can display date in UTC format using -u, or -utc, or universal option as shown below., $ date, Mon May 20 22:07:53 PDT 2013, $ date -u, Tue May 21 05:07:55 UTC 2013, , The current time after the above touch command is, 20:26:12, $ date, Sun May 20 20:26:12 PDT 2013, Finally, use the date command -r option to display the, last modified timestamp of a file as shown below. In this, example, it displays last modified time of datefile as, 20:25:57. It is somewhere between 20:25:48 and 20:26:12, (which is when we execute the above touch command to, modify the timestamp)., , 7. Display Last Modification Time using -r option, , $ date -r datefile, , In this example, the current time is 20:25:48, , Sun May 20 20:25:57 PDT 2013, , $ date, , 8. Various Date command formats, , Sun May 20 20:25:48 PDT 2013, , You can use formatting option to display date command, in various formats using the following syntax:, $ date +%<format-option>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 105
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Command, , Description, , • apropos whatis, , Show commands pertinent to string. See, also threadsafe, , • man -t ascii | ps2pdf - > ascii.pdf, , make a pdf of a manual page, , which command, , Show full path name of command, , time command, , See how long a command takes, Start stopwatch. Ctrl-d to stop. See also, sw, , • time cat, dir navigation, • cd -, , Go to previous directory, , • cd, , Go to $HOME directory, , (cd dir && command), , Go to dir, execute command and return to, current dir, Put current dir on stack so you can popd, back to it, , • pushd ., file searching, • alias l='ls -l --color=auto', , quick dir listing. See also l, , • ls -lrt, , List files by date. See also newest and, find_mm_yyyy, , • ls /usr/bin | pr -T9 -W$COLUMNS, , Print in 9 columns to width of terminal, , find -name '*.[ch]' | xargs grep -E 'expr', , Search 'expr' in this dir and below. See, also findrepo, , find -type f -print0 | xargs -r0 grep -F 'example', , Search all regular files for 'example' in, this dir and below, , find -maxdepth 1 -type f | xargs grep -F, 'example', , Search all regular files for 'example' in, this dir, , find -maxdepth 1 -type d | while read dir; do, echo $dir; echo cmd2; done, , Process each item with multiple, commands (in while loop), , • find -type f ! -perm -444, , Find files not readable by all (useful for, web site), , • find -type d ! -perm -111, , Find dirs not accessible by all (useful for, web site), , • locate -r 'file[^/]*\.txt', , Search cached index for names. This re is, like glob *file*.txt, , • look reference, , Quickly search (sorted) dictionary for, prefix, , • grep --color reference /usr/share/dict/words, , Highlight occurances of regular, expression in dictionary, , archives and compression, gpg -c file, , Encrypt file, , gpg file.gpg, , Decrypt file, , tar -c dir/ | bzip2 > dir.tar.bz2, , Make compressed archive of dir/, , bzip2 -dc dir.tar.bz2 | tar -x, , Extract archive (use gzip instead of bzip2, for tar.gz files), , tar -c dir/ | gzip | gpg -c | ssh user@remote 'dd Make encrypted archive of dir/ on remote, of=dir.tar.gz.gpg', machine, , 106, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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set operations (Note you can export LANG=C for speed. Also these assume no, duplicate lines within a file), sort file1 file2 | uniq, , Union of unsorted files, , sort file1 file2 | uniq -d, , Intersection of unsorted files, , sort file1 file1 file2 | uniq -u, , Difference of unsorted files, , sort file1 file2 | uniq -u, , Symmetric Difference of unsorted files, , join -t'\0' -a1 -a2 file1 file2, , Union of sorted files, , join -t'\0' file1 file2, , Intersection of sorted files, , join -t'\0' -v2 file1 file2, , Difference of sorted files, , join -t'\0' -v1 -v2 file1 file2, , Symmetric Difference of sorted files, , math, • echo '(1 + sqrt(5))/2' | bc -l, , Quick math (Calculate φ). See also bc, , • seq -f '4/%g' 1 2 99999 | paste -sd-+ | bc -l, , Calculate π the unix way, , •, , echo 'pad=20; min=64;, (100*10^6)/((pad+min)*8)' | bc, , More complex (int) e.g. This shows max, FastE packet rate, , •, , echo 'pad=20; min=64; print, (100E6)/((pad+min)*8)' | python, , Python handles scientific notation, , •, , echo 'pad=20; plot [64:1518], (100*10**6)/((pad+x)*8)' | gnuplot -persist, , Plot FastE packet rate vs packet size, , • echo 'obase=16; ibase=10; 64206' | bc, , Base conversion (decimal to, hexadecimal), , • echo $((0x2dec)), , Base conversion (hex to dec) ((shell, arithmetic expansion)), , • units -t '100m/9.58s' 'miles/hour', , Unit conversion (metric to imperial), , • units -t '500GB' 'GiB', , Unit conversion (SI to IEC prefixes), , • units -t '1 googol', , Definition lookup, , • seq 100 | paste -s -d+ | bc, , Add a column of numbers. See also add, and funcpy, , calendar, • cal -3, , Display a calendar, , • cal 9 1752, , Display a calendar for a particular month, year, , • date -d fri, , What date is it this friday. See also day, , •, , [ $(date -d '12:00 today +1 day' +%d) = '01' ], || exit, , exit a script unless it's the last day of the, month, , • date --date='25 Dec' +%A, , What day does xmas fall on, this year, , • date --date='@2147483647', , Convert seconds since the epoch (197001-01 UTC) to date, , • TZ='America/Los_Angeles' date, , What time is it on west coast of US (use, tzselect to find TZ), , •, , date --date='TZ="America/Los_Angeles" 09:00, next Fri', , What's the local time for 9AM next Friday, on west coast US, , locales, • printf "%'d\n" 1234, , Print number with thousands grouping, appropriate to locale, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 109
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.29, , MS WORD 2010 THEORY, Objectives : At the end of this lesson you shall be able to, • state what is MS Office, • brief what is MS Word and starting steps, • explain various screen blocks of MS Word, • explain procedures to create, save, print a documentl., Microsoft office is a application software package, introduced by Microsoft Corporation. MS Office consists, of the following popular packages :, , The Ribbon tab of Word has eight major parts viz. File,, Home, Insert, Page Layout, References, Mailings,, Review and View., , •, , Microsoft Word, , •, , Microsoft Excel, , •, , Microsoft Powerpoint, , •, , Microsoft Access, , •, , Microsoft Outlook, , File tab of the ribbon is useful to create a new file, a, blank or a template page as required. Ctrl + N always, create a new blank document in Office Package. The, documents so created can be saved as default word, document or given compatible format. Furthermore,, permission for accessing a documents can be fixed,, share a document on a network, even manage a, document to be compatible with previous and external, versions. Print option makes the document to get a hard, copy or a pdf format according to the installed printer, features. Recently opened files can also be viewed to, find it easy to work again. Help on word is there in the, same tab., , Word 2010, It is a word processor package that helps to create and, edit a document. It is the most known word processor of, nowadays. It makes professional looking documents by, providing a comprehensive set of tools for creating and, formatting a document, memos, letters, reports,, brochures, business documents and even internet web, pages., Starting Word, , Fig. 2 Home Tab, , Fig 2, , Fig 1 - Default page layout, , Copa 1182902, , Click on the Start > (windows Logo) All programmes >, Microsoft office > Microsoft Word. MS Word opens along, with a default blank document with default settings page, layout., , Home tab has clipboard options including cut, copy, paste, and paste special. The Font block has all the options of, setting fonts, size, superscript, subscript, bold, italic,, underline, strikethrough, font colors, etc., , Fig 1, , Fig 3 - Paragraph Group, , Unlike previous version, MS Office 2010 has a common, set of features for all the components. It makes it easy, to understand and common utilities to remain available, on all the packages of MS Office including Word, Excel,, PowerPoint, Access, etc. Many features are redesigned, so as enabling the diverted users of other packaged can, afford with. These enhancements and utilities in Word, 2010 are described as below., , Copa 1182903, , Copa 1182901, , Fig 3, , Paragraph group creates the formatting paragraphs with, alignments left, right, center, justify and indentations, para, and line spacing. Line and page breaks allows to create, pagination options and exceptions of formatting., , Copyright @ NIMI Not to be Republished, , 113
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Fig 4 - Styles and Editing Group, , Symbols group inserts symbols of equations like math, equations or symbols like currency, math symbols, etc., Copa 1182904, , Fig 4, , Fig 8 - Themes and Page Setup Group, , Fig 8, , Copa 1182905, , Fig 5, , Page group makes cover pages, blank pages insertion, and page breaks. Tables group helps to insert a table in a, text document with ready specified row-column set or a, customized table format. Illustration group inserts pictures, from external sources, cliparts, shapes, smart art, charts, of data, even screenshot into the text document., Fig 6 - Links and Header/Footer Groups, , Page Layout tab has five major groups. Themes block, creates predefined template setup using themes on, documents. Even new themes customized can be, created and saved for future use., Page setup group has features on margin around, page, orientation i.e. vertical or horizontal, paper size, columns, to display, breaks, line numbers and hyphenation., Fig 9 - Page Background and Paragraph Group, Fig 9, Copa 1182909, , The Insert tab has 7 groups. Fig 5 - Pages, Tables and, Illustrations blocks (Fig 5), , Copa1182908, , The Styles group allows preformatted text styles like, Heading styles, Paragraph styles, Subtitles, etc. Custom, styles can also be stored with altered specifications. The, Editing group used to select specific area, find and / or, replace option in a specified area in text., , Page Background group creates a watermark, page, Background color and page borders. Paragraph block, has specified options already discussed in Home ->, Paragraph group., Copa1182906, , Fig 6, , Fig 10 - Arrange Group, , Fig 10, Copa 11829010, , Links group creates hyperlink on texts, bookmarks and, cross references in a document., The header and footer group inserts header, footer to be, appearing on every page and page numbers to display, as to placement area., , The arrange group creates position of objects, text, elements, text wrapping, arranging objects, aligning of, objects, grouping and transformations., , Fig 7 - Text and Symbols block, , Fig 7, , References tab has six blocks., , Text group allows creating text box, quick parts likely to, create brochures, designed text as WordArt, paragraph, styles, a signature line, date and time and an object insert, option., 114, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , Copa 11829011, , Fig 11, , C, , 1182907, , Fig 11 - TOC and Footnotes Group
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Fig 15 - Write and Insert fields Group, , Fig 15, Copa 11829015, , Table of contents creates the TOC of a particular, publication document automatically and upon, modifications updatable. Footnotes tab creates footnotes, of a page, block area which includes explanatory phrases, or references. Endnote makes the note at the end of the, document., Fig 12 - Citations, Bibilography and Captions Group, , Copa 11829012, , Fig 12, , Citation and Bibliography makes an external source as, citation, reference tables and credits of authors related, to the publication. Captions tab inserts a caption, table, of figures, cross references inside a text., , While writing a letter, it has many parts, which this mail, merge creates fields of Address Block, Greetings Line,, Merged field of content, labels, etc., Fig 16 - Preview Results and Finish Groups, Fig 16, , Copa 11829016, , Fig 13 - Index and Table of Authorities Group, , Copa 11829013, , Fig 13, , Index enters a value on a main topic or sub topic and, create the index accordingly. Table of authorities has, the citation mark includes the list of the cases, statutes, and other authorities cited in the document., , On successful completion of mail merge, it can be, previewed and checked for errors for each recipients, and edit accordingly. Upon validation the mail merge, gets finished., Fig 17 - Proofing and Language Groups, Fig 17, , Fig 14 - Create and Mailmerge Groups, , Mailings tab used to create mailing of a letter or order, using common mailing features. Create block makes, envelopes print using predefined formats as well as, custom formats. Labels can also be printed to which the, delivery address is mentioned., Mail merge block is used to create mail merge of a letter,, email. If a common letter is created and to be sent to, many recipients, this option allows to create an Address, block where the recipient's info should appear. Even, selective recipients can be listed as well as a new, recipient list can be created., , Copa 11829017, , Copa 11829014, , Fig 14, , Review tab here is used for the various document areas, to be reviewed. Proofing makes easier to check Spelling, and Grammar of a document. Accidental errors can be, corrected here. Research refines the search not only, inside the document, but also the referenced documents., Thesaurus identifies the completeness of the document, using the standard language compatibility of the region, like English UK or English USA etc. Word count shows, the analysis of the document as total words, total, characters, with and without spaces, no. of paragraphs,, lines, etc. Here Text blocks can also be included for, such analysis., Language Block helps to translate a page into the, installed other languages and to change the proofing, language. It requires the direct translator service from, Microsoft Online., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , 115
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Fig 18 - Comments & Tracking Group, , Fig 20 - Document views and show Groups, , Fig 18, , Comments group inserts a comment for a specific, paragraph or text block., Tracking group finds the changes made on a document, by other authors in a protected mode. For example, if a, document is created by user X and edited by user Y, is, tracked separately with Track marks., Fig 19 - Changes, Compare and Protect Groups, , Copa 11829020, , Copa 11829018, , Fig 20, , View tab shows the way of displaying the word document., Document views have a Print Layout, a common view, of Word, Full Screen Reading, minimises the tabs and, ribbons to disappear and easy to read, Web Layout, which, previews a html compatible view, Outline, views the basic, version of document in mere text mode and Draft mode, for a text editing mode., The Rulers, Gridlines and Navigation Pane can be shown, or hidden according to user preferences., Fig 21 - Zoom / Window / Macro Groups, , Fig 19, , Changes hence made on the documents can either then, accepted or rejected. More than a document can be, compared for similarity using Compare. Also the, document can be protected from editing by other authors., , 116, , Copa 11829021, , Copa 11829019, , Fig 21, , Also the view of the page can be Zoomed to full page, two, pages view, 100% of the document and custom view. To, make easy editing a document the window can be split, into two, a new window for a document to cut paste, etc., can be created and all open word documents can be, arranged for view. While formatting the documents, for, repetition of commands the Macro option can be used. It, uses the Record option to store the set of commands and, repeat it again on other part of document or on another, document on a single click., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.6.30 to 1.6.37, COPA- Word Processing Software, Creating a file, save and other options, Objectives: At the end of this lesson you shall be able to, • explain how to create a new document, save and print, • state how to edit, format text and document styles, • brief using tables inside word document with data, • explain how to create styles in a document and save for future use, • explain Few unique features of Word 2010, • brief the mail merge processing, Fig 1 - File Info view, , Fig 3 - Print options in word, , Fig 1, Fig, 22, , Fig 3, , Copa 11829024, , Copa 11829022, , Fig 24, , Word 2010 new document can be created as usual with, Ctrl + N or through File menu New option. Basically the, file created is saved as a word document extended format, as docx in word file., Fig 2 - Save options in Word, , The saved documents can be printed using the File Menu, -> Print option and the installed printer support makes it, easy to get the document printed. If Adobe Acrobat, Professional is installed, the same document can be, stored as a PDF file for sharing purposes. Apart from, printing and storage, the file created can be published in, web as a web page or template that can be used for, future publications in same format., , Copa 11829023, , Fig 23, 2, Fig, , It can be saved using save as option in any compatible, format or old versions of office, like 2003 or earlier versions., Main utility of the word software is the creation of word, processing documents. It may be any of a format like, publication, letter, brochure, etc. Word supports all type, of formatting to design a text based presentation. Also it, supports output files in major accepted formats according, to industry standards., , Basic concepts to be noted while using Word are Text, properties. It includes Font type, Font size, Text Color,, and usual decorations of text. Also creating of paragraphs, styles are to be kept in mind. Paragraph alignment has, left, right, center and justified settings. Text elements, may contain items like ordered list, unordered list, subsection lists. They are found there paragraph formatting, block of Home Tab. Indenting of text for creating Quotes, is also there inside the same tab. According to the page, size, line spacing and paragraph spacing can be adjusted,, like before and after paragraph spaces, line heights, etc., The Styles can be predefined to use as ready to put on, places where it required. Standard templates are, available but it allows to create custom styles too., Tables can be inserted for various utilities. Normal table, has adjustable width and columns so it can simply inserted, with Insert > Table option directly., , Copyright @ NIMI Not to be Republished, , 117
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Fig 4 - Table insert wizard options, , FigFig, 276, , Fig 4, , In case of custom sized table is required, it can be created, using insert table / draw table options. Insert table allows, custom values for columns, width and other properties., Draw table creates custom table using a pen drawing tool, through which new table can be drawn according to the, available text contents., Customizable Quick Access Tool Bar, Word 2010's Quick Access Toolbar displays all the, commonly used options. It is located in the top left side, corner of the application window, near the office button., By default it displays the following three options, Save,, Undo and Redo, but is customizable and you may easily, add more options to it. (Fig 5), , Navigation Pane, In the previous versions of Microsoft Office, one has to, use the Ctrl+F hotkey to find any word or phrase from, within a document. Word 2010 has added a new magic to, this option, Ctrl+F now summons a Navigation Pane that, appears on the left side of the document. You will see the, three views available by clicking on their respective tabs,, the Heading View, Thumbnail Page View, and the Search, Result View. (Fig 7), Fig 7, , Fig 28, , Fig 26, , Copa 11829026, , Copa 11829028, , Fig 5, , Copa 11829027, , Copa 11829025, , Fig 25, , Paste Preview, , Customizable Ribbon Button, Apparently the Ribbon button in Word 2010 looks like the, one in Word 2007. But there is one big addition, you may, customize the word 2010's Ribbon button. In order to, customize the Ribbon button navigate to the following option, Office Button > Word Option > Customize Ribbon. (Fig 8), , It happens with most users that after copying and pasting, something into their document, they need to undo the, some changes. Word 2010 has made it easy for users,, now you may eliminate this unnecessary step by using, the paste preview option. It allows users to paste only the, values or the formatting. (Fig 6), 118, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished
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Improved Collaborations, , 8, FigFig29, , Copa 11829029, , Microsoft Word 2010 has a new feature called coauthoring. It allows more than one authors to edit a, document at the same time. Word 2010 tells you how, many authors are editing the document and their changes, can be viewed too. (Fig 9), , Fig 9, , Copa 11829030, , Fig 30, , Screen Capture Tool, , Copa 11829032, , Fig 10, Fig 31, , Fig Fig, 32 11, , Copa 11829031, , Word 2010 includes a feature called Screen Capturing,, now there is no need to use a third party or additional tool, to capture a screenshot in order to use it in Word, just, simply use Word 2010's built in tool to capture any area of, the screen. A Screenshot may be taken by navigating to, the following option Insert > Screenshot. (Fig 10), , The Background Removal Option, Artistic Effects, In Word 2010 users can now apply a number of snazzy, artistic effects to the pictures. In order to add the artistic, effects to your document, Navigate to the following option, Insert > Illustrations > Picture. Then browse and select, the picture you want, Once the picture is added to your, document, then the Picture Tools contextual tab is, displayed and you will be able to see the new Artistic, Effects drop down button over here. (Fig 11), , Office 2010 has an awesome option by the name of, Background Removal, which simply removes the, background of any image. Yes, you don't need Photoshop, anymore to remove the background. First insert the, picture in your Word document from the Insert > Picture, option. Then locate the Background Removal tool and get, rid of the background. (Fig 12), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 119
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Ligatures, , Copa 11829033, , Fig33, 12, Fig, , You might have heard about Ligatures. They make the, fonts look fancy and they are also used to keep letters, separate allowing you to search the text as if the font, were regular. Its true that not all fonts support ligatures,, but a large variety of the fonts supports them. You may, enable them from Font Preferences > advanced, then select, the standard only option in the ligatures drop down box., (Fig 15), Fig 15, , Fig 36, , Office Backstage, The Office Backstage is a new concept, it is the enhanced, form of the plain old office button and provides a much, user-friendly menu. It helps users to manage documents,, presentations, or spreadsheets at a greater level. (Fig 13), , Interesting feature, right? Read more about it here., , Copa 11829036, , Copa 11829034, , Fig Fig, 3413, , Improved Spell Checks, Word 2010 has added some new features to its spell, checker, now it will detect the mistake and suggest, changing the sentence., , Fig, Fig 16, , New Art Effects in WordArt, , 37, , Just like other features, WordArt has been updated with, new colorful art effects. Select the text, then click Word, Art and a list of all the available options will be displayed., (Fig 14), , 120, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , Copa 11829037, , Fig 35, , Copa 11829035, , Fig 14
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Shortcut keys in Word 2010, Objective : at the end of the lesson you shall be able to, •, , Learn the shortcut keys in MS Word., CTRL+SHIFT+A, , converts the selected text to capital letters or vice versa, , CTRL+SHIFT+F, , Displays the Font dialog box., , CTRL+SHIFT+G, , Displays the Word Count dialog box., , CTRL+SHIFT+S, , Displays the Apply Styles task pane., , ALT+R, , Displays the Review tab, , ALT+CTRL+1, , Apply Heading 1, Similarly ALT + CTRL + 2 will apply heading 2, , CTRL+SHIFT+L, , Applies Bullets, , CTRL+SHIFT+F5, , Bookmark, , CTRL + B, , Bold Text, , CTRL + I, , Italic Text, , CTRL + U, , Underline Text, , CTRL+PAGE DOWN Browse Next, CTRL+E, , Navigate to the center Paragraph, , CTRL+SHIFT+ENTER, , Column Break, , CTRL+SHIFT+C, , Copy Format, , ALT+SHIFT+F7, , Dictionary, , ALT+CTRL+S, , Splits the Document, , CTRL+SHIFT+D, , Double Underline, , CTRL+END, , End of Document, , END, , End of line, , CTRL+SHIFT+P, , Font size select, , SHIFT+F5 or ALT+CTRL+Z, , Go Back to previous state, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 121
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.38, , Typing practice using open source typing tutor tools, Objectives : At the end of this lesson you shall be able to, • understand about typing software, • typing Tutor tools., You will be able to learn touch typing quickly and efficiently, with the program's intelligent practice lessons, useful, support functions and an extensive progress tracker. You, can also play a typing game and expand the program with, open lessons or make your own to meet your specific, needs., , The Typing Tutor Advantage, , Full courses for Beginner, Advanced and Expert typists, , •, , •, , Introduction course. First time using keyboard. The, course covers all characters typed on your keyboard., , •, , Beginner course. This course helps to learn the position, of keys on the keyboard. After completing this course,, you will know which finger to use to hit each key without, looking at the keyboard. The course also covers uppercase letters, special symbols, and the numeric pad., , •, , •, , Create classes to group your students, and Import, your entire student roster using our simple Student, Import tool., , •, , Statistical Graphs & Charts, Both students and teachers have access to detailed, graphs and statistics to track progress., , •, , Complete Course - Novice to Professional, Beginner, Intermediate, Advanced, and Specialty, Lessons to help typists of all levels., , •, , Fun Interactive Typing Games, Students can take a break from the exercises to, practice with several educational typing games., , Progress Tracking, The statistics reflect your typing speed, accuracy and, time-out, complete with a summary at the end of each, lesson., , •, , •, , and it suggests your next step: Go to the next lesson, or Try again comparing the results with Course goals., , •, , •, , You can evaluate your own performance or students at, any time by simply looking at charts., , •, , overall lesson rate, typing speed( WPM, CPM, KPM,, WPS, CPS, KPS ), accuracy and time-out are enabled, in the both: table and chart presentation, , •, , also, for each lesson, statistics by each character and, keystroke in the column charts, , •, , Reporting, Access and export detailed reporting data. Reports, and graphs exist for all levels of data., , Advanced course, helps to improve your typing speed, by memorizing frequently used syllables and words., Expert course helps you to perfect the skills acquired, by typing an actual text., , Easy to Get Started, , Typing Test, Students can repeat the typing test to track their, progress over time., Helpful Typing Hints & Tips, Tips and helpful technique information is constantly, provided to reinforce proper typing techniques., , •, , On-Screen Keyboard & Hand Diagram, Key position and proper finger placement is always, displayed to keep beginners from looking at their, hands., , Copyright @ NIMI Not to be Republished, , 123
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IT & ITES, Related Theory for Exercise 1.7.39 to 1.7.41, COPA - Spread Sheet Application, Introduction to MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Features & Functions of Microsoft Excel, Whether for work or home use, an Excel spreadsheet is, the best tool in Microsoft Office for organizing data and, making lists. Although Word documents can include, tables and columns, Excel makes laying out information, for easier. Excel also has a range of functions for designing, formulas that automate calculations. Although Excel looks, intimidating at first, the program's layout is similar to other, Office applications., Cells and Worksheets, The main portion of Excel's window consists of a, spreadsheet -- or worksheet of cells. Just as with a paper, spreadsheet, each cell can contain any numbers or any, text -- unlike working with an Access database, Excel, allows to simply click on any cell and fill it however best, fits the project., In some cases, such as to track spending, if want to use, an organized series of rows and columns. Other times,, such as building a list of team members, cell order and, positioning won't play a major role. One advantage to, Excel is how simple it makes reorganizing data: select a, cell and drag its border to move it to a new spot on the, sheet., Excel Workbooks, Every Excel file, called a workbook, contains one or more, worksheets. To switch between sheets in a workbook,, use the tabs in the lower left corner of the window. Since, Excel 2010, most workbooks use the file extension XLSX,, , 124, , whereas older versions used XLS files. New copies of Excel, can read these old files, but to open a new workbook in an, old edition, the old PC needs the Office compatibility pack., Formulas and Functions, In addition to containing plain text and numbers, cells, can contain formulas, which always start with an equals, sign. With a formula, Excel displays the result of an, equation in a cell, but automatically keeps that result, up-to-date as you change its components. A basic formula, can take the place of a calculator: write "=2+4" and Excel, displays "6." Formulas also work with data in other cells:, "=A1+B1" adds the values of cells A1 and B1., For procedures other than direct arithmetic, use functions, to perform various operations on data. Functions' abilities, range from simple math, such as "AVERAGE" to average, a range of cells, to modifying text, such as "LOWER" to, convert a line to lower case., The two terms are often confused, but remember that, each cell can contain only one formula, but each formula, can use multiple functions, such as "=AVERAGE(A1,, B1)+SUM(A2, B2)" to add the sum of two cells to the, average of two other cells., The following basic window appears when you start the, excel application. Let us, now understand the various important parts of this window, as shown in fig-1., Ribbon Tabs, , Copyright @ NIMI Not to be Republished
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Copa 1203901, , Fig 1, , As with the rest of Office since 2007, Microsoft has, replaced Excel's menus with ribbon tabs as shown in, fig-2. The tab as visual menus that remain open each, tab contains a set of related features with explanatory, icons. For example, the Home tab contains the most, common options, such as font and text color, while the, Insert tab offers ways to insert tables, text boxes and, charts. One tab, File, behaves differently. File still, contains basic tasks including "New," "Open" and "Save,", but displays these tasks in a full-screen area with extra, options, called the backstage view. For example, the, "New" button in the backstage view offers a searchable, selection of templates for new workbooks., , Fig 2, , Copa 1203902, , Ribbon contains commands organized in three, , components:, Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert, Page, Layout is the examples of ribbon tabs., Groups: They organize related commands; each group, name appears below the group on the Ribbon. For, example, group of commands related to fonts or group, of commands related to alignment etc., ?Home: Use this tab when creating, formatting, and, editing a spreadsheet., This tab is arranged into the Clipboard, Font, Alignment,, Number, Styles, Cells, and Editing groups., , Insert: Use this when adding particular elements (including, graphics, PivotTables, charts, hyperlinks, and headers and, footers) to a spreadsheet. This tab is arranged into the, Tables, Illustrations, Sparkline, Filter, Charts, Links, and, Text groups., Page Layout: Use this tab when preparing a spreadsheet, for printing or reordering graphics on the sheet. This tab, is arranged into the Themes, Page Setup, Scale to Fit,, Sheet Options, and Arrange groups., Formulas: Use this tab when adding formulas and, functions to a spreadsheet or checking a worksheet for, formula errors. This tab is arranged into the Function, Library, Defined Names, Formula Auditing, and, Calculation groups. Note that this tab also contains a, Solutions group when activate certain add-in programs,, Data: Use this tab when importing, querying, outlining,, and subtotaling the data placed into a worksheet's data, list. This tab is arranged into the Get External Data,, Connections, Sort & Filter, Data Tools, and Outline, groups., Review: Use this tab when proofing, protecting, and, marking up a spreadsheet for review by others. This tab, is arranged into the Proofing, Language, Comments, and, Changes groups. Note that this tab also contains an Ink, group with a sole Start Inking button if you're running, Office 2010 on a Tablet PC or on a computer equipped, with some sort of electronic input tablet., View: Use this tab when changing the display of the, Worksheet area and the data it contains. This tab is, arranged into the Workbook Views, Show, Zoom,, Window, and Macros groups., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 125
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Title Bar, , Status Bar, , This lies in the middle and at the top of the window. Title, bar shows the program and the sheet titles., , This displays the sheet information as well as the insertion, point location. From left to right, this bar can contain the, total number of pages and words in the document,, language etc., , Help, The Help Icon can be used to get excel related help, anytime you like. Thisprovides nice tutorial on various, subjects related to excel., Zoom Control, Zoom control lets to zoom in for a closer look at your, text. The zoom control consists of a slider that user can, slide left or right to zoom in or out. The + buttons can be, clicked to increase or decrease the zoom factor., View Buttons, The group of three buttons located to the left of the Zoom, control, near the, bottom of the screen, lets to switch among excel's various, sheet views., Normal Layout view: This displays the page in normal, view., , user can configure the status bar by right-clicking, anywhere on it and byselecting or deselecting options, from the provided list, File Tab, The File tab replaces the Office button from Excel 2010., user can click it to check the Backstage view, where, user come to open or save files, create new sheets, print, a sheet, and do other file-related operations., Quick Access Toolbar, TheFile tab and its purpose is to provide a convenient, resting place for the Excel's most frequently used, commands. And customize this toolbar based on the, comfort., Dialog Box Launcher(Fig-3), , Page Layout view: This displays pages exactly as they, will appear when printed. This gives a full screen look of, the document., , This appears as a very small arrow in the lower-right, corner of many groups on the Ribbon. Clicking this button, opens a dialog box or task pane that providesmore, options about the group., , Page Break view: This shows a preview of where pages, will break when printed., , If already have an opened sheet then it will display a, window showing the, , Sheet Area, , details about the opened sheet as shown fig-4. Backstage, view shows threecolumns when select most of the, available options in the first column., , The area where to enter data. The flashing vertical bar, is called the insertion point and it represents the location, where text will appear when type., Row Bar, , Fig 3, , Rows are numbered from 1 onwards and keeps on, increasing as to keepentering data. Maximum limit is, 1,048,576 rows., Columns are numbered from A onwards and keeps on, increasing as to keep, entering data. After Z, it will start the series of AA, AB, and so on. Maximum limit is 16,384 columns., First column of the backstage view will have the following options as shown in, Table-1:, Option, , Description, , Save, , If an existing sheet is opened, it would be saved as is,otherwise it will display a dialogue, box asking for thesheet name., , Save As, , A dialogue box will be displayed asking for sheet nameand sheet type. By default, it will, save in sheet 2010 format with extension .xlsx., , Open, , This option is used to open an existing excel sheet., , Close, , This option is used to close an opened sheet., , Info, , This option displays the information about the openedsheet., , 126, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , Copa 1203903, , Column Bar
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Option, , Description, , Recent, , This option lists down all the recently opened sheets., , New, , This option is used to open a new sheet., , Print, , This option is used to print an opened sheet., , Save & Send, , This option saves an opened sheet and displays options to send the sheet using email etc., , Help, , You can use this option to get the required help about excel 2010., , Options, , Use this option to set various option related to excel 2010., , Exit, , Use this option to close the sheet and exit., , Sheet Information, When click Info option available in the first column, it, displays the following information in the second column, of the backstage view:, , Fig 5, , Compatibility Mode: If the sheet is not a native excel, 2007/2010 sheet, a Convert button appears here,, enabling to easily update its format. Otherwise, this, category does not appear., Permissions: This option used to protect the excel sheet., And can set a password so that nobody can open the, sheet, or lock the sheet so that nobody can edit the sheet., , Versions: If the sheet has been saved several times,, and may be able to access previous versions of it from, this section., Sheet Properties, When click Info option available in the first column, it, displays various properties in the third column of the, backstage view. These properties include sheet size, title,, tags, categories etc., user can also edit various properties. Just try to click on, the property value and if property is editable, then it will, display a text box where can add the text like title, tags,, comments, Author., , Copa 1203905, , Prepare for Sharing: This section highlights important, information should know about the sheet before send it, to others, such as a record of the edits the made as, developed the sheet., , Sheet area is the place of type the text. The flashing vertical, bar iscalled the insertion point and it represents the location, where text will appearwhen type. When click on a box, then the box is highlighted. When double click the box,, the flashing vertical bar appears and can start entering the, data., So, just keep the mouse cursor at the text insertion point, and start typing whatever text would like to type. We, have typed only two words "HelloExcel" as shown fig-6., The text appears to the left of the insertion point., Fig 6, , Entering values, , Copa 1203906, , A new sheet is displayed by default when open an excel, sheet as shown in the fig-5 screen shot., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 127
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There are following three important points, which would help while typing:, • Press Tab to go to next column., •, , Press Enter to go to next row., , •, , Press Alt + Enter to enter a new line in the same, column., , Move Around in Excel 2010, Excel provides a number of ways to move around a sheet, using the mouse and the keyboard., , First of all, let us create some sample text before we, proceed. Open a new excel sheet and type any data. A, sample data table as shown table-2 and fig-7., , OrderDate, , Region, , Rep, , Item, , Units, , Unit Cost, , Total, , 1/6/2010, , East, , Jones, , Pencil, , 95, , 1.99, , 189.05, , 1/23/2010, , Central, , Kivell, , Binder, , 50, , 19.99, , 999.5, , 2/9/2010, , Central, , Jardine, , Pencil, , 36, , 4.99, , 179.64, , 2/26/2010, , Central, , Gill, , Pen, , 27, , 19.99, , 539.73, , 3/15/2010, , West, , Sorvino, , Pencil, , 56, , 2.99, , 167.44, , 4/1/2010, , East, , Jones, , Binder, , 60, , 4.99, , 299.4, , 4/18/2010, , Central, , Andrews, , Pencil, , 75, , 1.99, , 149.25, , 5/5/2010, , Central, , Jardine, , Pencil, , 90, , 4.99, , 449.1, , 5/22/2010, , West, , Thompson, , Pencil, , 32, , 1.99, , 63.68, , 6/8/2010, , East, , Jones, , Binder, , 60, , 8.99, , 539.4, , 6/25/2010, , Central, , Morgan, , Pencil, , 90, , 4.99, , 449.1, , 7/12/2010, , East, , Howard, , Binder, , 29, , 1.99, , 57.71, , 7/29/2010, , East, , Parent, , Binder, , 81, , 19.99, , 1,619.19, , 8/15/2010, , East, , Jones, , Pencil, , 35, , 4.99, , 174.65, , Moving with Mouse, , Table-2, , Mouse can easily move the insertion point by clicking in, the text anywhere on the screen. Sometime if the sheet, is big then user cannot see a place need to move. In, such situations, to use the scroll bars, as shown fig-8, screen shot., , Copa 1203907, , Fig 7, , 128, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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User can move box by box or sheet by sheet. Now click, in any box containing data in the sheet. It would have to, hold down the Ctrl key while pressing an arrow key, which, moves the insertion point as described here -, , Fig 8, , Copa 1203908, , Key Combination, , Where the Insertion Point, Moves, , Ctrl +, , Î, , To the last box containing data, of the current row., , Ctrl +, , Í, , To the first box containing data, of the current row., , Ctrl +, , Ï, , To the first box containing data, of the current column., , Ctrl +, , Ð, , To the last box containing data, of the current column., , Ctrl + Page Up, , To the sheet in the left of the, current sheet., , user can scroll the sheet by rolling mouse wheel, which, is equivalent to clicking the up-arrow or down-arrow, buttons in the scroll bar., , Ctrl + Page Down, , To the sheet in the right of the, current sheet., , Ctrl + Home, , To the beginning of the sheet., , Moving with Scroll Bars, , Ctrl + End, , To the end of the sheet., , As shown in the above screen capture, there are two, scroll bars: one for moving vertically within the sheet,, and one for moving horizontally. Using the vertical scroll, bar, user may ?, •, , Move upward by one line by clicking the upwardpointing scroll arrow., , •, , Move downward by one line by clicking the downwardpointing scroll arrow., , •, , Move one next page, using next page button, (footnote)., , •, , Move one previous page, using previous page button, (footnote)., , •, , Use Browse Object button to move through the sheet,, going from one chosen object to the next., , Moving with Go To Command, Press F5 key to use Go To command as shown in fig-9,, which will display a dialogue box contains various options, to reach to a particular box., Normally, we use row and column number, for example, K5 and finally press Go To button., , Fig 9, , Moving with Keyboard, , Keystroke, , Where the Insertion Point Moves, , Î, , Forward one box, , Í, , Back one box, , Ï, , Up one box, , Ð, , Down one box, , PageUp, , To the previous screen, , Copa 1203909, , The following keyboard commands, used for moving, around your sheet, also move the insertion point -, , PageDown To the next screen, Home, , To the beginning of the current screen, , End, , To the end of the current screen, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 129
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Conditional Formatting, , •, , MS Excel 2010 Conditional Formatting feature enables, to format a range of values so that the values outside, certain limits, are automatically formatted., Choose Home Tab " Style group " Conditional Formatting, dropdown., Various Conditional Formatting Options, •, , Top/Bottom Rules: It opens a continuation menu, with various options for defining the formatting rules, that highlight the top and bottom values, percentages,, and above and below average values in the cell, selection., , Suppose want to highlight the top 10% rows user can do, this with these Top/Bottom rules as shown in fig-12., , Fig 12, , Highlight Cells Rules ? It opens a continuation menu, with various options for defining the formatting rules, that highlight the cells in the cell selection that contain, certain values, text, or dates, or that have values, greater or less than a particular value, or that fall, within a certain ranges of values., , Copa 12039012, , Suppose to find cell with Amount 0 and Mark them as, red. Choose Range of cell " Home Tab " Conditional, Formatting DropDown " Highlight Cell Rules " Equal To as, on fig-10., , Fig 10, , Copa 12039010, , •, , Data Bars(fig-13): It opens a palette with different, color data bars that can apply to the cell selection to, indicate their values relative to each other by clicking, the data bar thumbnail., , With this conditional Formatting data Bars will appear in, each cell., , Fig 13, , After Clicking ok, the cells with value zero are marked as, red as shown in fig-11., , Copa 12039013, , Fig 11, , •, , Color Scales (Fig-14): It opens a palette with different, three- and two-colored scales that can apply to the, cell selection to indicate their values relative to each, other by clicking the color scale thumbnail., , Copa 12039011, , See the below screenshot with Color Scales, conditional, formatting applied., , 130, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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Linking Excel Worksheet Data Overview, , Fig 14, , In Excel, a link is a formula that dynamically pulls in, data from a cell in another worksheet. The worksheet, can be in the same workbook or a different workbook., , Copa 12039014, , The destination worksheet is the worksheet that contains, the link formula. The worksheet containing the data that, will be brought in is called the source worksheet., , • Icon Sets (Fig-15)? It opens a palette with different, sets of icons that can apply to the cell selection to indicate, their values relative to each other by clicking the icon, set., See the below screenshot with Icon Sets conditional, formatting applied., , Fig 15, , Any time the cell value in the source worksheet changes,, the cell containing the link formula will be updated as, well the next time the spreadsheet containing the link, formula is opened. This is just one of many reasons the, Excel software program is so powerful., Need for Linking Spreadsheet Data, The ability to create links often eliminates the need to, have identical data entered and updated in multiple, sheets. This saves time, reduces errors, and improves, data integrity. For example, a company's prices can be, stored in a 'Master Price List' worksheet, and others, needing pricing data can link to that worksheet., Consider a Sales Manager who has a detailed, spreadsheet for each salesperson, but would like a, summary sheet to compare salespersons' performance, and create grand totals. The summary sheet (destination), would bring in data from all the salespersons' sheets, (source)., Create the Worksheet Link, Before creating the link, format the cell, containing the link formula in the destination, worksheet to equal the format of the source data., For example, if the data from the source spreadsheet is, currency with 2 decimal points, then first format the target, cell for currency with 2 decimal places., , • New Rule: It opens the New Formatting Rule dialog, box, where define a custom conditional formatting rule, to apply to the cell selection., • Clear Rules: It opens a continuation menu, where, can remove the conditional formatting rules for the cell, selection by clicking the Selected Cells option, for the, entire worksheet by clicking the Entire Sheet option, or, for just the current data table by clicking the This Table, option., • Manage Rules: It opens the Conditional Formatting, Rules Manager dialog box, edit and delete particular rules, as well as adjust their rule precedence by moving them, up or down in the Rules list box., Link Excel Spreadsheet Data, Microsoft Excel provides the ability for cells in one, worksheet to be linked to cells in one or more other, worksheets. This is a great productivity tool and can, reduce the need for additional worksheets!, , METHOD ONE, 1. In the source worksheet, select the cell need to link, to and click the Copy button on the Home tab. Or, press Ctrl+C, or right-click and select Copy., 2. Switch to the destination spreadsheet and click the, cell want to link. Then, depending on the version of, Excel:, •, , Excel 2007, 2010, and 2013: On the Home tab, click, the down arrow below Paste and click Paste Link. In, newer versions also right-click and select the Paste, Link from the Paste menu., , •, , Excel 2003 and older versions: On the Edit menu,, click Paste Special, and then click Paste Link., , 3. Return to the source worksheet and press ESC to, remove the animated border around the cell., METHOD TWO, This is a fast method that works in a different order than, Method One., , 1. In the destination worksheet cell that will contain the, link formula, enter an equal sign (=)., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, 131, , Copyright @ NIMI Not to be Republished
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2. In the source worksheet, click in the cell that contains, the data and press the Enter key., , Fig 16, , Link Formula Example(Fig-16), In the example below, using Method One, we click in cell, B6 in the source worksheet and click Copy. Then, on the, destination worksheet, we click in cell B3, and paste the, link. The value ($3,500) automatically displays., , Copa 12039016, , Follow the same steps to link the data from the Denver, and Seattle worksheets to the Store Totals worksheet., And first formatted the cells to display the data as Currency., (Fig 16), , 132, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.7.42 - 1.7.46, COPA - Spread Sheet Application, Functions and formulas in MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Formulas in MS Excel, formula, worksheet will be just simple tabular, representation of data. A formula consists of special code,, which is entered into a cell. It performs some calculations, and returns a result, which is displayed in the cell., Formulas use a variety of operators and worksheet, functions to work with values and text. The values and, text used in formulas can be located in other cells, which, makes changing data easy and gives worksheets their, dynamic nature. For example, it can quickly change the, data in a worksheet and formulas works., Elements of Formulas, A formula can consist of any of these elements ?, •, , Creating Formula, For creating a formula need to type in the Formula Bar., Formula begins with '=' sign. When building formulas, manually, and can either type in the cell addresses or, can point to them in the worksheet. Using the Pointing, method to supply the cell addresses for formulas is often, easier and more powerful method of formula building., When using built-in functions, to click the cell or drag, through the cell range that want to use when defining, the function's arguments in the Function Arguments, dialog box as shown in Fig 1., Fig Fig, 17 1, , Mathematical operators, such as +(for addition), and *(for multiplication), , Example •, , Copa 12039017, , =A1+A2 Adds the values in cells A1 and A2., Values or text, , Example =200*0.5 Multiplies 200 times 0.5. This formula uses only, values, and it always returns the same result as 100., •, , Cell references (including named cells and, ranges), , Example =A1=C12 Compares cell A1 with cell C12. If the cells, are identical, the formula returns TRUE; otherwise, it, returns FALSE., •, , Worksheet functions (such as SUMor AVERAGE), , Example =SUM(A1:A12) Adds the values in the range A1:A12., , As soon as complete a formula entry, Excel calculates, the result, which is then displayed inside the cell within, the worksheet (the contents of the formula, however,, continue to be visible on the Formula bar anytime the, cell is active). If you make an error in the formula that, prevents Excel from being able to calculate the formula, at all, Excel displays an Alert dialog box suggesting how, to fix the problem., Functions in Formula, Many formulas are create use available worksheet, functions. These functions enable to greatly enhance the, power of the formulas and perform calculations that are, difficult if use only the operators. For example, and can, use the LOG or SIN function to calculate the Logarithm, or Sin ratio. And cannot do this complicated calculation, by using the mathematical operators alone., , Copyright @ NIMI Not to be Republished, , 133
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Using Functions, , Function Arguments, , When type = sign and then type any alphabet the, searched functions will showfig 2., , In the above examples, notice that all the functions used, parentheses. The information inside the parentheses is, the list of arguments., , Fig 2, Fig 18, , Copa 12039018, , Functions vary in how they use arguments. Depending, on what it has to do, a function may use., , Suppose need to determine the largest value in a range., A formula can't tell the answer without using a function., We will use formula that uses the MAX function to return, the largest value in the range B3:B8 as, =MAX(A1:D100)as shown in fig 3., , FigFig, 193, , •, , No arguments - Examples ? Now(), Date(), etc., , •, , One argument - UPPER(), LOWER(), etc., , •, , A fixed number of arguments - IF(), MAX(), MIN(),, AVERGAGE(), etc., , •, , Infinite number of arguments, , •, , Optional arguments, , Built In Functions, MS Excel has many built in functions, which we can use, in our formula. To see all the functions by category,, choose Formulas Tab " Insert Function as shown in fig-5., Then Insert function Dialog appears from which we can, choose the function., , Another example of functions. Suppose to find if the cell, of month is greater than 1900 then we can give Bonus to, Sales representative. The we can achieve it with writing, formula with IF functions as =IF(B9>1900,"Yes","No"), as shown in fig 4., , Copa 12039021, , Copa 12039019, , Fig 5, Fig 21, , Functions by Categories, Let us see some of the built in functions in MS Excel., Text Functions, LOWER: Converts all characters in a supplied text string, to lower case, , FigFig, 204, , UPPER : Converts all characters in a supplied text string, to upper case, TRIM : Removes duplicate spaces, and spaces at the, start and end of a text string, CONCATENATE : Joins together two or more text, strings., , Copa 12039020, , Fig 4, , 134, , LEFT : Returns a specified number of characters from, the start of a supplied text string., MID : Returns a specified number of characters from, the middle of a supplied text string, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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RIGHT : Returns a specified number of characters from, the end of a supplied text string., LEN: Returns the length of a supplied text string, FIND: Returns the position of a supplied character or text, string from within a supplied text string (case-sensitive)., Date & Time, DATE: Returns a date, from a user-supplied year, month, and day., TIME: Returns a time, from a user-supplied hour, minute, and second., DATEVALUE: Converts a text string showing a date, to, an integer that represents the date in Excel's date-time, code., , two supplied numbers., Filters in MS Excel, Filtering data in MS Excel refers to displaying only the, rows that meet certain conditions. (The other rows gets, hidden.), Using the store data, if user interested in seeing data, where Shoe Size is 36, then set filter to do this. Follow, the below mentioned steps to do this., •, , Place a cursor on the Header Row., , •, , Choose Data Tab ¾ Filter to set filter as shown in, fig 6., , Fig 22Fig 6, , TIMEVALUE: Converts a text string showing a time, to, a decimal that represents the time in Excel., NOW: Returns the current date & time., TODAY: Returns today's date., Statistical, , Copa 12039022, , MAX: Returns the largest value from a list of supplied, numbers., MIN: Returns the smallest value from a list of supplied, numbers., AVERAGE: Returns the Average of a list of supplied, numbers., COUNT: Returns the number of numerical values in a, supplied set of cells or values., COUNTIF: Returns the number of cells (of a supplied, range), that satisfies a given criteria., SUM: Returns the sum of a supplied list of numbers, , •, , Click the drop-down arrow in the Area Row Header and, remove the check mark from Select All, which unselects, everything., , •, , Then select the check mark for Size 36 which will filter, the data and displays data of Shoe Size 36 as shown, in fig-23., , •, , Some of the row numbers are missing; these rows, contain the filtered (hidden) data., , •, , There is drop-down arrow in the Area column now shows, a different graphic - an icon that indicates the column, is filtered. (Fig 7), , Logical, AND: Tests a number of user-defined conditions and, returns TRUE if ALL of the conditions evaluate to TRUE,, or FALSE otherwise, OR: Tests a number of user-defined conditions and, returns TRUE if ANY of the conditions evaluate to TRUE,, or FALSE otherwise., NOT: Returns a logical value that is the opposite of a, user supplied logical value or expression i.e. returns, FALSE if the supplied argument is TRUE and returns, TRUE if the supplied argument is FAL, , Fig 7, Fig 23, , Math & Trig, , SIGN: Returns the sign (+1, -1 or 0) of a supplied number., SQRT: Returns the positive square root of a given, number., MOD: Returns the remainder from a division between, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , Copa 12039023, , ABS: Returns the absolute value (i.e. the modulus) of a, supplied number., , 135
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Using Multiple Filters(fig-24), , 10, FigFig26, , Filtering of records by multiple conditions i.e. by multiple, column values. Suppose after size 36 is filtered,need to, have the filter where color is equal to Coffee. After setting, filter for Shoe Size, choose Color column and then set, filter for color. (Fig 8), , Copa 12039026, , Copa 12039024, , Fig 8, Fig 24, , -, , Values - alphabetically or numerically., , -, , Cell Color - Based on Color of Cell., , Sorting in MS Excel, , -, , Font Color - Based on Font color., , Sorting data in MS Excel rearranges the rows based on, the contents of a particular column. sort a table to put, names in alphabetical order Or sort data by Amount from, smallest to largest or largest to smallest., , -, , Cell Icon - Based on Cell Icon., , •, , Clicking Ok will sort the data as on fig 11., , To Sort the data follow the steps mentioned below., •, , Fig Fig, 27 11, , Select the Column to sort data as on fig 9., , Choose Data Tab " Sort Below dialog appears., , •, , If the user sort data based on a selected column,, Choose Continue with the selection or if the data, sorting based on other columns, choose Expand, Selection., , •, , Sort the data based on the below Conditions as on, fig 10., , Sorting option is also available from the Home Tab. Choose, Home Tab " Sort & Filter. You can see the same dialog to, sort records as on fig 12., , Fig 28, , Fig 12, , Copa 12039028, , •, , Copa 12039027, , 12039025, , 9, FigFig25, , 136, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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Ranges in MS Excel:, A cell is a single element in a worksheet that can hold a, value, some text, or a formula. A cell is identified by its, address, which consists of its column letter and row, number. For example, cell B1 is the cell in the second, column and the first row., , to return the navigation keys to normal movement., •, , Type the cell or range address into the Name box and, press Enter. Excel selects the cell or range that, specified. (Fig 13), , Fig 13, Fig 29, , A group of cells is called a range. You designate a range, address by specifying its upper-left cell address and its, lower-right cell address, separated by a colon., •, , C24, , - A range that consists of a single cell., , •, , A1:B1, , - Two cells that occupy one row and two, columns., , •, , A1:A100 - 100 cells in column A., , •, , A1:D4, , Copa 12039029, , Example of Ranges:, , - 16 cells (four rows by four columns)., , Selecting Ranges (Fig-29), Selecting a range in several ways ?, , Selecting Complete Rows and Columns (Fig-30), , •, , Press the left mouse button and drag, highlighting, the range. Then release the mouse button. If drag to, the end of the screen, the worksheet will scroll., , When user need to select an entire row or column.and, can select entire rows and columns in much the same, manner as select ranges:, , •, , Press the Shift key while uses the navigation keys to, select a range., , •, , Click the row or column border to select a single row, or column., , •, , Press F8 and then move the cell pointer with the, navigation keys to highlight the range. Press F8 again, , •, , To select multiple adjacent rows or columns, click a, row or column border and drag to highlight additional, rows or columns., , •, , To select multiple (nonadjacent) rows or columns,, press Ctrl while click the row or column borders., (Fig 14), , Copa 12039030, , Fig, Fig14, 30, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , 137
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IT & ITES, Related Theory for Exercise 1.7.47 & 1.7.48, COPA - Spread Sheet Application, Data validations and Table management in MsExcel 2010, Objectives : At the end of this lesson you shall be able to, • data Validation, • data Table with Example, • charts and its types, • pivot table and pivot chart, • page setup and printing worksheet, • excel shortcut keys, Data Validation, , •, , MS Excel data validation feature allows to set up certain, rules that dictate what can be entered into a cell. For, example, user want to limit data entry in a particular cell, to whole numbers between 0 and 10. If the user makes, an invalid entry, and display a custom message as shown, fig 1., , Decimal - The user must enter a number. For example,, you can specify that the entry must be greater than or, equal to 10 and less than or equal to 20., , •, , List - The user must choose from a list of entries you, provide. You will create drop-down list with this, validation. You have to give input ranges then those, values will appear in the drop-down., , •, , Date - The user must enter a date. You specify a valid, date range from choices in the Data drop-down list., For example, you can specify that the entered data, must be greater than or equal to January 1, 2013, and, less than or equal to December 31, 2013., , •, , Time - The user must enter a time. Specify a valid, time range from choices in the Data drop-down list., For example, user can specify that the entered data, must be later than 12:00 p.m., , •, , Text Length - The length of the data (number of, characters) is limited. specify a valid length by using, the Data drop-down list. For example, that the length, of the entered data be 1 (a single alphanumeric, character)., , •, , Custom - To use this option, must supply a logical, formula that determines the validity of the user's entry, (a logical formula returns either TRUE or FALSE)., , Copa 12039031, , FigFig311, , Validation Criteria, To specify the type of data allowable in a cell or range,, follow the steps below, which shows all the three tabs of, the Data Validation dialog box., •, , Select the cell or range., , •, , Choose Data " Data Tools " Data Validation. Excel, displays its Data Validation dialog box having 3 tabs, settings, Input Message and Error alert., , Input Message Tab(fig 2), Fig 2, , Fig 32, , Here user can set the type of validation. Choose an option, from the Allow drop-down list. The contents of the Data, Validation dialog box will change, displaying controls, based on your choice., •, , Any Value - Selecting this option removes any existing, data validation., , Whole Number - The user must enter a whole, number.For example, you can specify that the entry, must be a whole number greater than or equal to 50., 138, •, , Copyright @ NIMI Not to be Republished, , Copa 12039032, , Settings Tab
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User can set the input help message with this tab. Fill the, title and Input message of the Input message tab and the, input message will appear when the cell is selected., , Fig 5, Fig 34, , Error Alert Tab(fig 3), , User specify an error message with this tab. Fill the title, and error message. Select the style of the error as stop,, warning or Information as per user need., , Copa 12039034, , Copa 12039032, , FigFig, 323, , Now, for creation of data table select the range of data, table. Choose Data Tab " What-If analysis dropdown ", Data table. It will display dialogue asking for Input row and, Input Column. Give the Input row as Price cell (In this, case cell B3) and Input column as quantity cell (In this, case cell B4) as shown in fig 6., Fig 6, Fig 35, , Data Table with Example (Fig 4), Fig 4, , Copa 12039033, , Copa 12039035, , Fig 33, , Fig 36, , Fig 7, , Copa 12039036, , Here user have the Price and quantity of many values., Also, have the discount for that as third variable for, calculating the Net Price. And can keep the Net Price, value in the organized table format with the help of the, data table. The Price runs horizontally to the right while, quantity runs vertically down. We are using a formula to, calculate the Net Price as Price multiplied by Quantity, minus total discount (Quantity * Discount for each, quantity) as shown in fig 5., , Clicking OK will generate data table as shown in fig 7. It, will generate the table formula. And change the price, horizontally or quantity vertically to see the change in, the Net Price., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 139
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Charts, A chart is a visual representation of numeric values., Charts (also known as graphs) have been an integral, part of spreadsheets. Charts generated by early, spreadsheet products were quite crude, but thy have, improved significantly over the years. Excel provides, you with the tools to create a wide variety of highly, customizable charts. Displaying data in a well-conceived, chart can make your numbers more understandable., Because a chart presents a picture, charts are particularly, useful for summarizing a series of numbers and their, interrelationships., , •, , Stock: This chart type is most often used for stock, price data, but can also be used for scientific data, (for example, to indicate temperature changes)., , •, , Surface: A surface chart is useful to find the optimum, combinations between two sets of data. As in a, topographic map, colors and patterns indicate areas, that are in the same range of values., , •, , Doughnut: Like a pie chart, a doughnut chart shows, the relationship of parts to a whole; however, it can, contain more than one data series., , •, , Bubble: Data that is arranged in columns on a, worksheet, so that x values are listed in the first, column and corresponding y values and bubble size, values are listed in adjacent columns, can be plotted, in a bubble chart., , •, , Radar: A radar chart compares the aggregate values, of a number of data series., , Types of Charts, There are various chart types available in MS Excel as, shown in fig 8., Fig 8, , Fig 37, , Creating Chart, , •, , Column: Column chart shows data changes over a, period of time or illustrates comparisons among items., , •, , Bar: A bar chart illustrates comparisons among, individual items., , •, , Pie: A pie chart shows the size of items that make up, a data series, proportional to the sum of the items. It, always shows only one data series and is useful to, emphasize a significant element in the data., , •, , Line: A line chart shows trends in data at equal, intervals., , •, , Area: An area chart emphasizes the magnitude of, change over time., , •, , X Y Scatter: An xy (scatter) chart shows the, relationships among the numeric values in several, data series, or plots two groups of numbers as one, series of xy coordinates., , •, , Select the data for which you want to create the chart., , •, , Choose Insert Tab " Select the chart or click on the, Chart groupto see various chart types., , •, , Select the chart of the choice and click OK to generate, the chart as shown in fig 9., Fig 9, Fig 38, , Copa 12039038, , Copa 12039037, , To create charts for the data by below mentioned steps., , Editing Chart, You can edit the chart at any time after you have created, it., •, , 140, , select the different data for chart input with Right click, on chart " Select data. Selecting new data will, generate the chart as per the new data, as shown in, fig 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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This will generate the Pivot table pane as shown in fig-41., various options available in the Pivot table pane. And can, select fields for the generated pivot table. (Fig 13), , Fig 10, Fig 39, , •, , change the X axis of the chart by giving different inputs, to X-axis of chart., , •, , change the Y axis of chart by giving different inputs to, Y-axis of chart., , Pivot Tables, A pivot table is essentially a dynamic summary report, generated from a database. The database can reside in, a worksheet (in the form of a table) or in an external, data file. A pivot table can help transform endless rows, and columns of numbers into a meaningful presentation, of the data. Pivot tables are very powerful tool for, summarized analysis of the data., Pivot tables are available under Insert tab " PivotTable, dropdown " PivotTable., Pivot Table Example (Fig-40), Now, let us see Pivot table with the help of example., Suppose huge data of voters and need to see the, summarized data of voter Information per party, use the, Pivot table for it. Choose Insert tab " Pivot Table to insert, pivot table. MS Excel selects the data of the table. and, select the pivot table location as existing sheet or new, sheet. (Fig 11), , Copa 12039041, , Copa 12039039, , FigFig, 4112, , •, , Column labels: A field that has a column orientation, in the pivot table. Each item in the field occupies a, column., , •, , Report Filter: User can set the filter for the report as, year, and then data gets filtered as per the year., , •, , Row labels: A field that has a row orientation in the, pivot table. Each item in the field occupies a row., , •, , Values area: The cells in a pivot table that contain, the summary data. Excel offers several ways to, summarize the data (sum, average, count, and so, on)., , After giving input fields to the pivot table, it generates the, pivot table with the data as shown in fig 13., FigFig, 4213, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , Copa 12039042, , Copa 12039040, , Fig 40Fig 11, , 141
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Pivot Charts, , •, , A pivot chart is a graphical representation of a data, summary, displayed in a pivot table. A pivot chart is, always based on a pivot table. Although Excel lets to, create a pivot table and a pivot chart at the same time,, user can't create a pivot chart without a pivot table. All, Excel charting features are available in a pivot chart., , Press Ctrl+P and then click the Print button (or press, Enter)., , FigFig, 4516, , Pivot charts are available under Insert tab ¾ PivotTable, dropdown ¾ PivotChart., Pivot Chart Example, , Copa 12039045, , Suppose huge data of voters and need to see the, summarized view of the data of voter, Information per party in the form of charts, then use the, Pivot chart for it. Choose Insert tab ¾ Pivot Chart to, insert the pivot table. (Fig 14), , FigFig, 4314, Adjusting Common Page Setup Settings, , Copa 12039043, , User can adjust the print settings available in the Page, setup dialogue in different ways as discussed below. Page, setup options include Page orientation, Page Size, Page, Margins, etc., , MS Excel selects the data of the table. And select the, pivot chart location as an existing sheet or a new sheet., Pivot chart depends on automatically created pivot table, by the MS Excel. generate the pivot chart in the below, fig 15., , •, , The Print screen in Backstage View, displayed when, choose File " Print., , •, , The Page Layout tab of the Ribbon., , Choosing Your Printer(fig-46), To switch to a different printer, choose File ¾ Print and, use the drop-down control in the Printer section to select, any other installed printer. (Fig 17), Fig 17, , Fig 46, , Quick Print, If user want to print a copy of a worksheet with no layout, adjustment, use the Quick Print option. There are two, ways in which we can use this option., •, , Copa 12039046, , Copa 12039044, , Fig Fig, 4415, , Specifying What You Want to Print(Fig 18), Sometimes print only a part of the worksheet rather than, the entire active area. Choose File ¾ Print and use the, controls in the Settings section to specify what to print., •, , Active Sheets: Prints the active sheet or sheets that, you selected., , Choose File " Print (which displays the Print pane),, and then click the Print button as shown in fig 16., , 142, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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•, , Entire Workbook: Prints the entire workbook, including, chart sheets., , •, , Selection: Prints only the range that selected before, choosing File ¾ Print., , MS Excel Keyboard Short-cuts, MS Excel offers many keyboard short-cuts. Below is the list of all the major shortcut keys in Microsoft Excel., (Fig 18), , Copa 12039047, , FigFig, 4718, , •, , Ctrl + A, , -, , Selects all contents of the worksheet., , •, , Ctrl + B, , -, , Bold highlighted selection., , •, , Ctrl + I, , -, , Italicizes the highlighted selection., , •, , Ctrl + K, , -, , Inserts link., , •, , Ctrl + U, , -, , Underlines the highlighted selection., , •, , Ctrl + 1, , -, , Changes the format of selected cells., , •, , Ctrl + 5, , -, , Strikethrough the highlighted selection., , •, , Ctrl + P, , -, , Brings up the print dialog box to begin printing., , •, , Ctrl + Z, , -, , Undo last action., , •, , Ctrl + F3, , -, , Opens Excel Name Manager., , •, , Ctrl + F9, , -, , Minimizes the current window., , •, , Ctrl + F10, , -, , Maximize currently selected window., , •, , Ctrl + F6, , -, , Switches between open workbooks or windows., , •, , Ctrl + Page up, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Page down, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Tab, , -, , Moves between Two or more open Excel files., , •, , Alt + =, , -, , Creates a formula to sum all of the above cells, , •, , Ctrl + ', , -, , Inserts the value of the above cell into cell currently selected., , •, , Ctrl + Shift + !, , -, , Formats the number in comma format., , •, , Ctrl + Shift + $, , -, , Formats the number in currency format., , •, , Ctrl + Shift + #, , -, , Formats the number in date format., , •, , Ctrl + Shift + %, , -, , Formats the number in percentage format., , •, , Ctrl + Shift + ^, , -, , Formats the number in scientific format., , •, , Ctrl + Shift + @, , -, , Formats the number in time format., , •, , Ctrl + Arrow key, , -, , Moves to the next section of text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 143
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•, , Ctrl + Space, , -, , Selects the entire column., , •, , Shift + Space, , -, , Selects the entire row., , •, , Ctrl + -, , -, , Deletes the selected column or row., , •, , Ctrl + Shift + =, , -, , Inserts a new column or row., , •, , Ctrl + Home, , -, , Moves to cell A1., , •, , Ctrl + ~, , -, , Switches between showing Excel formulas or their values in cells., , •, , F2, , -, , Edits the selected cell., , •, , F3, , -, , After a name has been created F3 will paste names., , •, , F4, , -, , Repeat last action. For example, if you changed the color of text in another, cell pressing F4 will change the text in cell to the same color., , •, , F5, , -, , Goes to a specific cell. For example, C6., , •, , F7, , -, , Spell checks the selected text or document., , •, , F11, , -, , Creates chart from the selected data., , •, , Ctrl + Shift + ;, , -, , Enters the current time., , •, , Ctrl + ;, , -, , Enters the current date., , •, , Alt + Shift + F1, , -, , Inserts New Worksheet., , •, , Alt + Enter, , -, , While typing text in a cell pressing Alt + Enter will move to the next line, allowing for multiple lines of text in one cell., , •, , Shift + F3, , -, , Opens the Excel formula window., , •, , Shift + F5, , -, , Brings up the search box., , 144, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.8.49 - 1.8.57, COPA - Image Editing and Presentations, Image editing, presentations, Objectives : At the end of this lesson you shall be able to, • Introduction to Power Point and its advantages, • Creation of slide shows, • Fine tuning of presentations, Introduction, , Working with PowerPoint 2010, , PowerPoint is a presentation graphics software program, that is part of the Microsoft Office package. It uses a, graphical approach for the presentations in the form of, slide shows that accompany the oral delivery of the topic., This program is widely used in business and classrooms, and is an effective tool when used for training purposes., , Step 1: Click the Start button., , PowerPoint 2010 allowsto create presentations for printing or online viewing using a variety of tools. These include wizards to help with the content and look and feel, of the presentations to animation tools to create moving, images., , Copa 1214901, , PowerPoint is one of the simplest computer programs, to learn. It is the easiest program used worldwide for, presentations that creates professional looking presentations. It is easy to customize presentations with company logo and has design templates that come with the, programs. In addition to an on screen slide show,, PowerPoint has printing options that allow the presenter, to provide handouts and outlines for the audience as, well as notes pages for the speaker to refer to during the, presentation., , Fig 1, , Step 2: Click All Programs option from the menu., , Fig 2, , Presentation, , Copa 1214902, , A presentation is a collection of data and information, that is to be delivered to a specific audience. A, PowerPoint presentation is a collection of electronic, slides that can have text, pictures, graphics, tables, sound, and video. This collection can run automatically or can, be controlled by a presenter., Advantage and application of PowerPoint 2010, Professional looking presentations, , •, , Animated presentations shown on a monitor or overhead screen, , •, , Notes for the speaker, , •, , Handouts for the audience, , •, , Paper printouts of your slide, , •, , Overhead projector transparencies, , •, , Movies, , Step 3: Search for Microsoft Office from the sub menu, and click it., Fig 3, , Copa 1214903, , •, , Copyright @ NIMI Not to be Republished, , 145
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Step 4: Search for Microsoft PowerPoint 2010 from the, submenu and click it., , Fig 4, , File Tab, This tab opens the Backstage view which basically allows to manage the file and settings in PowerPoint. This, can save presentations, open existing ones and create, new presentations based on blank or predefined templates. The other file related operations can also be executed from this view., Ribbon, , This will launch the Microsoft PowerPoint 2010 application and the following is the presentation window., , Copa 1214905, , Fig 5, , Copa 1214907, , Copa 1214904, , Fig 7, , The ribbon contains three components:, •, , Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert,, Page Layout are examples of ribbon tabs., , •, , Groups: They organize related commands; each, group name appears below the group on the Ribbon., For example, a group of commands related to fonts, or a group of commands related to alignment, etc., , •, , Commands: Commands appear within each group, as mentioned above., , Title Bar, This is the top section of the window. It shows the name, of the file followed by the name of the program which in, this case is Microsoft PowerPoint., Slide Area, This is the area where the actual slide is created and, edited.Add, edit and delete text, images, shapes and, multimedia is supported in this section., , PowerPoint Screen, Fig 6, , Help, The Help Icon can be used to get PowerPoint related, help anytime. Clicking on the "?" opens the PowerPoint, Help window where there is a list of common topics to, browse from. Specific topics from the search bar at the, top can also be used for searching., Zoom Options, The zoom control zooms in for a closer look at the text., The zoom control consists of a slider that can slide left, or right to zoom in or out, - and + buttons to can be used, to increase or decrease the zoom factor. The maximum, zoom supported by PowerPoint is 400% and the 100%, is indicated by the mark in the middle., , Copa 1214906, , Slide Views, The group of four buttons located to the left of the Zoom, control, near the bottom of the screen, lets to switch, between PowerPoint views., •, , 146, , Normal Layout view: 1 This displays page in normal, view with the slide on the right and a list of thumbnails to the left. This view allowsuser to edit individual, slides and also rearrange them., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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•, , Slide Sorter view: This displays all the slides as a, matrix. This view only allows the user to rearrange, the slides but not edit the contents of each slide., , •, , Reading View: This view is like a slideshow with access to the Windows task bar in case the user need, to switch windows. However, like the slideshow user, cannot edit anything in this view., , •, , First Pane ? This is the commands pane which consists of all the commands that would typically found, in the file menu of older versions. it also has the, Options menu which edits the options on the program, like customizing the ribbon., , Various commands under the first pane are described in, the table below ?, S.No, , Notes Section, , 1, , This sections allows user to add notes for the presentation. These notes will not be displayed on the screen, during the presentation; these are just quick reference, for the presenter., , Command & Description, Save, This allows user to save a new file or an existing, file in standard format. If user is working on a pre, viously saved file this will save the new changes, in the same file format. If user is working on a, new file, this command would be similar to the, Save As command., , Quick Access Toolbar, The Quick Access Toolbar is located just under the ribbon. This toolbar offers a convenient place to group the, most commonly used commands in PowerPoint. User, can customize this toolbar to suit their needs., , 2, , Save As, Allows user to specify the file name and the file, type before saving the file., , Slide Tab, 3, , This section is available only in the Normal view. It displays all the slides in sequence. User can add, delete, and reorder slides from this section., , Open, Allows user to open new PowerPoint files., , 4, , Backstage View in Powerpoint 2010, , Close, Allows user to close an existing file., , In Office 2010, Microsoft replaced the traditional file, menu with the new Backstage view. This view not only, offers all the menu items under the file menu, but additional details which makes management of files a lot, easier., , 5, , Info, Displays the information about the current file., , 6, , Recent, Lists series of recently viewed or edited, PowerPoint files., , Accessing Backstage View, User can access the Backstage view simply by clicking, on the File tab. They can exit this view by clicking on, any tab (including the File tab again). 'Esc' button on, the keyboardcanalso be pressed for the same., , 7, , New, Allows user to create a new file using blank or, pre-defined templates., , Organization of Backstage View, , 8, , The backstage view has three sections or panes., , Print, Allows user to select the printer settings and print, the presentation., , Fig 8, , 9, , Save & Send, Allows user to share your presentation with larger, audience via emails, web, cloud services, etc., , 10, , Help, Provides access to PowerPoint Help., , 11, , Options, Allows user to set various options related to, PowerPoint program., , Copa 12149008, , 12, , Exit, Closes the presentation and exits the program., , •, , Second Pane ? This is the subcommands pane. This, will list all the commands related to the main command chosen in the first pane. For example, if user, selects Print in the first pane, user get to choose the, printer and adjust the print settings in the second pane., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 147
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•, , Third Pane ? This is the preview or file information page., Depending on the command and the subcommand user, select, this pane will either display the properties of, the file or give a preview of the file., , Creating Presentation using Powerpoint 2010, PowerPoint offers a host of tools that will aid the user in creating a presentation. These tools are organized logically, into various ribbons in PowerPoint. The table below describes the various commands that can be accessed from the, different menus., Menu Category, , Ribbon Commands, , Home, , Clipboard functions, manipulating slides, fonts, paragraph settings, drawing objects and, editing functions., , Insert, , Insert tables, pictures, images, shapes, charts, special texts, multimedia and symbols., , Design, , Slide setup, slide orientation, presentation themes and background., , Transitions, , Commands related to slide transitions., , Animations, , Commands related to animation within the individual slides., , Slide Show, , Commands related to slideshow set up and previews., , Review, , Proofing content, language selection, comments and comparing presentations., , View, , Commands related to presentation views, Master slides, color settings and window arrange, ments., , Besides these depending on the objects selected in the, slide, there are other menu tabs that get enabled., Add New Slides in Powerpoint 2010, The following are the steps that allows the user to insert, a new slide ., , Step 2: The new slide is inserted. The layout of this slide, can be changed to suit the design requirements., , Fig 10, , Step 1: Right-click in the Navigation Pane under any, existing slide and click on the New Slide option., , Copa 1214909, , Copa 12149010, , Fig 9, , 148, , Step 3: To change the slide layout, right-click on the, newly inserted slide and go to the Layout option where, user can choose from the existing layout styles available ., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Subtitle Box, , Fig 11, , This is found only in slides with the Title layout. This is, indicated by "Click to add subtitle", , Copa 12149011, , Copa 12149013, , Fig 13, , Same steps can be followed to insert a new slide in between existing slides or at the end on the slide list., When we insert a new slide, it inherits the layout of its, previous slide with one exception. If inserting a new, slide after the first slide (Title slide), the subsequent slide, will have the Title and Content layout., , Fig 12, , Content Box, This is found in most of the slides that have a placeholder for adding content. This is indicated by "Click to, add text". This box allows user to add text as well as, non-text content. To add text to such a box, click anywhere on the box, except on one of the content icons in, the center and start typing., , Copa 12149014, , Copa 12149012, , Fig 14, , Adding Text in Boxes in Powerpoint 2010, PowerPoint allows users to add text to the slide in a, well-defined manner to ensure the content is well distributed and easy to read. The procedure to add the text, in a PowerPoint slide is always the same - just click in, the text box and start typing. The text will follow the default formatting set for the text box, although this formatting can be changed later as required., The most common content blocks in PowerPoint are:, , Text Only Box, This is not a default content box available in PowerPoint,, but user can create it using Slide Master, if required., This is also indicated by "Click to add text". The only, difference between the Text Only Box and the Content, Box is that the former only supports text in the content, area., , Title Box, This is typically found on slides with the title layout and, in all the slides that have a title box in them. This box is, indicated by "Click to add title"., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 149
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Fig 18, , Copa 12149016, , Fig 16, , Adding New Text Boxes in Powerpoint 2010, , Copa 12149018, , Most of the standard layouts come with the text box option. As mentioned, text boxes will have "Click to add, text" as the default text. Here are the steps to add new, text boxes in slide., Step 1: Click on the Text Box icon in the Home ribbon, under the Drawingsection., , Copa 12149016, , Fig 16, , Step 4: Alternately, user can click and drag the cursor, without releasing the click to create a text box., , Fig 19, , Step 2 : User will get the insert text box cursor that looks, like an inverted cross., , Copa 12149019, , Fig 17, , The size of the text box can be adjusted by selecting, one of the edges marked by squares or corners marked, by circles., , Copa 12149017, , Slide Show in Powerpoint 2010, , Fig 20, Copa 12149020, , Step 3: Click to insert a text box. User can now start, typing directly into the text box., , Most PowerPoint presentations are created to be run as, a slideshow. Most of these features of Powerpoint 2010, are really to help user create a good slideshow without, having to go through the entire presentation over and, over again after every minor change. Features related, to running the slideshow are grouped under the Slideshow, ribbon., , 150, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Section, , Menu Item, , Description, , Start Slideshow, , From Beginning, , Starts slideshow from beginning, , From Current Slide, , Starts slideshow from the current slide, , Broadcast Slideshow, , Allows users to broadcast the slideshows, using Microsoft's PowerPoint Broadcast Service, , Custom Slideshow, , Builds a custom slideshow by picking the slides you, want to run, , Set Up Slideshow, , Helps set up the slideshow including browser/ full screen, display, show options with or without narration/ animation,, pen and laser color during the slideshow and the slides to, be presented during the show, , Hide Slide, , Helps mark/ unmark the slide as hidden, so it is skipped or, shown during the slideshow respectively, , Rehearse Timing, , Allows users to rehearse the timing on each slide and the, entire slideshow, , Record Slideshow, , Records the slideshow including narration and animation, , Slideshow Checkboxes, , Helps set or avoid the use of narrative audio and rehearsed, timings during the show. Display media controls in the, slideshow view, , Resolution, , Defines resolution in slideshow view, , Show Presentation on, , Picks the monitor to display the presentation one - in case, of multiple monitors, , Use Presenter View, , Run presentation in Presenter view rather than just slideshow, view, , Set Up, , Monitors, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 151
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IT & ITES, Related Theory for Exercise 1.9.58 - 1.9.61, COPA - Database Management Systems, Concepts of data and Databases, Objectives : At the end of this lesson you shall be able to, • explain database structure and control, • describe Ms access database utilities., Microsoft Access is a Database Management System, (DBMS) from Microsoft that combines the relational, Microsoft Jet Database Engine with a graphical user, interface and software-development tools. It is a member, of the Microsoft Office suite of applications, included in, the professional and higher editions., •, , Microsoft Access is just one part of Microsoft's overall, data management product strategy., , •, , It stores data in its own format based on the Access, Jet Database Engine., , •, , Like relational databases, Microsoft Access also, allows you to link related information easily. For, example, customer and order data. However, Access, 2013 also complements other database products, because it has several powerful connectivity features., , •, , It can also import or link directly to data stored in, other applications and databases., , •, , As its name implies, Access can work directly with, data from other sources, including many popular PC, database programs, with many SQL (Structured, Query Language) databases on the desktop, on, servers, on minicomputers, or on mainframes, and, with data stored on Internet or intranet web servers., , •, , Access can also understand and use a wide variety, of other data formats, including many other database, file structures., , •, , You can export data to and import data from word, processing files, spreadsheets, or database files, directly., , •, , Access can work with most popular databases that, support the Open Database Connectivity (ODBC), standard, including SQL Server, Oracle, and DB2., , •, , Software developers can use Microsoft Access to, develop application software., , •, , Report (optional): Information from the database is, organized in a nicepresentation that can be printed, in an Access Report., , Architecture, •, , Access calls anything that can have a name an object., Within an Access desktop database, the main objects, are tables, queries, forms, reports, macros, data, macros, and modules., , •, , If you have worked with other database systems on, desktop computers, you might have seen the term, database used to refer to only those files in which, you store data., , •, , But, in Access, a desktop database (.accdb) also, includes all the major objects related to the stored, data, including objects you define to automate the, use of your data., , RDBMS, In the computing system (web and business applications),, there are enormous data that comes out every day from, the web. A large section of these data is handled by, Relational database management systems (RDBMS)., The idea of relational model came with E.F.Codd's 1970, paper "A relational model of data for large shared data, banks" which made data modeling and application, programming much easier. Beyond the intended benefits,, the relational model is well-suited to client-server, programming and today it is predominant technology for, storing structured data in web and business applications., MS Access - RDBMS, Microsoft Access has the look and feel of other Microsoft, Office products as far as its layout and navigational, aspects are concerned, but MS Access is a database, and, more specifically, a relational database., •, , Microsoft Access stores information which is called a, database. To use MS Access, you will need to follow, these four steps:, , Before MS Access 2007, the file extension was *.mdb,, but in MS Access 2007 the extension has been, changed to *.accdb extension., , •, , Database Creation: Create your Microsoft Access, database and specify what kindof data you will be, storing., , Early versions of Access cannot read accdb, extensions but MS Access 2007 and later versions, can read and change earlier versions of Access., , •, , An Access desktop database (.accdb or .mdb) is a, fully functional RDBMS., , •, , It provides all the data definition, data manipulation,, and data control features that you need to manage, large volumes of data., , •, , •, , Data Input: After your database is created, the data, of every business day canbe entered into the Access, database., , •, , Query: This is a fancy term to basically describe the, process of retrievinginformation from the database., , 152, , Copyright @ NIMI Not to be Republished
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You can use an Access desktop database (.accdb or, .mdb) either as a standalone RDBMS on a single, workstation or in a shared client/server mode across a, network., , •, , A desktop database can also act as the data source, for data displayed on webpages on your company, intranet., , •, , When you build an application with an Access desktop, database, Access is the, , RDBMS., Data Definition, Let us now understand what Data Definition is:, •, , •, , •, , In document or a spreadsheet, you generally have, complete freedom to define the contents of the, document or each cell in the spreadsheet., In a document, you can include paragraphs of text, a, table, a chart, or multiple columns of data displayed, with multiple fonts., In spreadsheet, you can have text data at the top to, define a column header for printing or display, and, you might have various numeric formats within the, same column, depending on the function of the row., , •, , An RDBMS allows you to define the kind of data you, have and how the data should be stored., , •, , You can also usually define rules that the RDBMS, can use to ensure the integrity of your data., , •, , For example, a validation rule might ensure that the, user can't accidentally store alphabetic characters in, a field that should contain a number., , Data Manipulation, Working with data in RDBMS is very different from, working with data in a word processing or spreadsheet, program., •, , In a word processing document, you can include, tabular data and perform a limited set of functions on, the data in the document., , •, , You can also search for text strings in the original, document and, with ActiveX controls, include tables,, charts, or pictures from other applications., , •, , In a spreadsheet, some cells contain functions that, determine the result you want, and in other cells, you, enter the data that provides the source information, for the functions., , •, , An RDBMS provides you many ways to work with, your data. For example,, , •, , You can search a single table for information or, request a complex search across several related, tables., , •, , You can update a single field or many records with a, single command., , •, , You can write programs that use RDBMS commands, to fetch data that you want to display and allow the, user to update the data., , Access uses the powerful SQL database language to, process data in your tables. Using SQL, you can define, the set of information that you need to solve a particular, problem, including data from perhaps many tables., Data Control, Spreadsheets and word processing documents are great, for solving single-user problems, but they are difficult to, use when more than one person needs to share the data., •, , When you need to share your information with others,, RDBMS gives you the flexibility to allow multiple users, to read or update your data., , •, , An RDBMS that is designed to allow data sharing, also provides features to ensure that no two people, can change the same data at the same time., , •, , The best systems also allow you to group changes, (which is also known as transaction) so that either all, the changes or none of the changes appear in your, data., , •, , You might also want to be sure that no one else can, view any part of the order until you have entered all, of it., , •, , Because you can share your Access data with other, users, you might need to set some restrictions on, what various users are allowed to see or update., , Designing a Database, The first step in creating a database is to think about, why you need it-what is its purpose? Once you know the, answer, you can begin designing your own database., Ask yourself questions like What kinds of information, will it store? How will I have to break down this information, so it can be stored in my database? How will I use the, data once it's in there?, The bookstore scenario, The best way to learn about designing a database is to, jump right in to the process. Let's pretend we work for, the bookstore, and we need to build a database for the, store to use. Let's think about what we might need the, database to do for us., The following diagram shows that we have customers and, sell books via orders, both in the store and online., , Fig 1, , Copa 1225801, , •, , The store needs a way to keep track of these things., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 153
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Determine the purpose of the database, The first step of designing a database is to determine the, purpose of the database. What do we need it to do?, At Ready-2-Read, our customers will place orders for, books. At the very least, we will want our database to, track the books we sell, the customers we sell them to,, and the date of each of the orders., The database will also be able to tell us where our, customers live when we need to send them books or, coupons. Additionally, we can use it to track our sales or, to make a bestseller list to post in the store., Plan database tables, Once we've established its purpose, we can begin about, how to break up the information into the tables the, database will need to store data. Recall that a table is a, collection of records, and each record is broken up into, the smallest pieces of needed information, called fields., , Book the customer is ordering, and the Date the order is, placed., Creating a new database with Access, When you launch Access 2007/2010, you will see the, Getting Started window., In the left pane, the template categories-including the, featured local templates-are listed, as well as the, categories on Office Online. Templates are prebuilt, databases focused on a specific task that you can, download and use immediately., You will also see the New Blank Database option, which, allows you to build your own database from scratch., , Fig 2, , Customers, , -, , Orders, , -, , Books, , Plan table fields, Once you know what tables you need, the next step is, deciding what fields belong in each table. Remember, that fields are the smallest chunk of information in any, record., Let's look at our Ready-2-Read bookstore example again., There will be several fields in our Customers table. We'll, obviously want each customer's first name and last name., We'll also need an address if we need to send a customer, his order. Email will be necessary if we need to contact, the customer if there is an issue with the order., Customers, , Books, , Orders, , First Name, , Title, , Customer, , Last Name, , Author First, , Book, , Street, , Author Last, , Date, , City, , Price, , State, , Category, , When you choose the New Blank Database option at the, top of the window, you will be prompted to rename the, database from the default name, which is, Database1.accdb. Rename the database whatever you, want. In the example below, we named the database, Ready2Read because it's the name of the store in our, scenario., Fig 3, , Copa 1225803, , -, , Copa 1225802, , Because we're planning a database to track our, customers, the books we have, and the orders our, customers place, we will need a table for each one of, these., , Pin/Zip Code, Email, We will also need several fields in the Books table. Title, and Author make sense for books. We'll need a Price for, each book. Category will help usknow what type of books, sell the best so we can order more books that fit into this, category., The Orders table will have fewer fields. We'll need this, table to track the Customer who is placing the order, the, 154, , Click Create to finish naming the database., Setting up tables, The new database opens with one table showing as a, default. It also defaults to naming this table Table1 in both, the navigation pane and the Table tab itself. You will want, to name your tables based on your database design plan., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Copa 1225804, , Naming a table, To give the table a unique name, you must first click on, the Microsoft Office button in the upper-left corner of the, application., , Copa 1225807, , Fig 7, , Fig 4, , TIP: Give your tables logical, easy-to-understand names., To rename a table:, With the table closed, right-click the Table you want to, rename in the navigation pane. Select the Rename option, that appears in the menu., Fig 8, , Next, select Save from the menu. The Save As dialog box, will appear to let you save the table whatever name you, want., Fig 6, , Copa 1225808, , Copa 1225805, , Fig 5, , The table name will be highlighted and a cursor will appear,, which means you can now type the new name right there., Left-click anywhere outside of the table name to make the, change., To close a table:, , Copa 1225806, , There are several ways to close an active table. You can, right-click the Table tab and choose Close from the menu., Fig 9, , Copa 1225809, , The new table names appear in both the navigation pane, and the Table tab itself, as you can see in the picture, below., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 155
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A more common method is to click the X that appears in, the top-right corner of the active database object window., , Copa 12258010, , Fig 10, , To open a table:, To open a table, right-click the Table name of the table, you want to open in the navigation pane, then choose, Open from the menu., , Fig 11, , Next, select Table from the Tables command group. A, new table will open in the active database object window., You must name your table using the Save command, from Microsoft Office menu., Adding fields to a table, Access 2007 allows you to add fields to tables when you, are:, •, , Working in Datasheet view, which looks like a, spreadsheet, , •, , Working in Design view, where you are able to set more, controls for your fields, , Either way, you need to know how to switch between the, two views., To switch views:, Select the Views command group from either the Home, tab (seen below) or the Datasheet tab on the Ribbon. Select, the view option you want from the menu., , A more common method is to double-click the table name, in the navigation pane. The selected table will open in, the active database object window., Adding more tables to the database, By default, Access 2007 starts out with one table. To add, more tables to the database, click the Create tab on the, Ribbon., , Fig 12, , Copa 12258013, , Copa 12258011, , Fig 13, , Adding fields in Datasheet view, By default, Access 2007 creates one field in each new, table: the ID field. This field auto-numbers to give each, record in the table a unique number identifier. Recall, that records are the rows in a table. You may want to, rename the ID field with a unique name because the ID, field appears automatically in every table you create., While this is not necessary, it may help avoid confusion, when setting up table relationships., , 156, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258014, , Copa 12258012, , Fig 14
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To add more fields to a table in Datasheet view, doubleclick the Add New Field header., Fig 15, , To add a new field to a table in Design view, click in the, cell where you want the new field and type the field name., When you switch back to Datasheet view, your new field, appears as its own column, as seen below., , The Add New Field text will disappear from the header., Name the field by typing the name directly into the header., Press the Tab key on your keyboard to move to the next, field., Adding fields in Design view, In Design view, the field names are along the lefthand, column instead of across the top like in Datasheet view,, as seen below., , Copa 12258017, , Copa 12258015, , Fig 17, , Datatypes, Every field in a table has properties and these properties, define the field's characteristics and behavior. The most, important property for a field is its data type. A field's data, type determines what kind of data it can store. MS Access, supports different types of data, each with a specific, purpose., •, , The data type determines the kind of the values that, users can store in any given field., , •, , Each field can store data consisting of only a single, data type., , Copa 12258016, , Fig 16, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 157
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Here are some of the most common data types you will find used in a typical Microsoft Access database., Type of Data, , Description, , Size, , Text or combinations of text and numbers,, Short Text, , Up to 255, , including numbers that do not require, characters. calculating (e.g. phone numbers)., , Long Text, , Lengthy text or combinations of text and, , Up to 63, 999, , numbers. characters., Numeric data used in mathematical, Number, , 1, 2, 4, or 8 bytes, , (16 bytes if set to calculations., Replication ID)., , Date/Time, , Date and time values for the years 100 through, , 8 bytes., , 9999., Currency values and numeric data used in, Currency, , mathematical calculations involving data with, , 8 bytes., , one to four decimal places., A unique sequential (incremented by 1), , 4 bytes (16 bytes if, , number or random number assigned by, AutoNumber, , set to Replication Microsoft Access whenever, a new record is ID). added to a table., Yes and No values and fields that contain only, , Yes/No, , 158, , one of two values (Yes/No, True/False, or, , 1 bit., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Here are some of the other more specialized data types, you can choose from in Access., Data Types, , Description, , Attachment, , Size, , Files, such as digital photos. Multiple files can be, attached per record. This data type is not available, , Up to about 2 GB., , in earlier versions of Access., OLE objects, , OLE objects can store pictures, audio, video, or, , Up to about 2 GB., , other BLOBs (Binary Large Objects), Hyperlink, , Text or combinations of text and numbers stored a, , Up to 8,192 (each, part of a Hyperlink, data type can, contain up to, 2048 characters)., , Lookup, , The Lookup Wizard entry in the Data Type column, in the Design view is not actually a data type. When, you choose this entry, a wizard starts to help you, , Dependent on, , define either a simple or complex lookup field., , the data type of, he lookup field., , Wizard, , A simple lookup field uses the contents of another, table or a value list to validate the contents of a, single value per row. A complex lookup field allows, you to store multiple values of the same data type, in each row., , Calculated, , You can create an expression that uses data from, , You can create, , one or more fields. You can designate different, , an expression, , result data types from the expression., , that uses data, from one or, more fields. You, can designate, different result, data types from, the expression., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 159
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MS Access - Adding Data, , Fig 21, , Adding records to tables, , Copa 12258021, , When you enter records into your table, you are, populating the database. In Access 2007, you can do this, a few different ways., To add records in the new record row:, Click the record row with the asterisk that appears at, the bottom of the table., •, Copa 12258018, , Fig 18, , Type the data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , To add records with the New Record navigation, button:, •, , Click the New Record button in the navigation bar. The, navigation bar is located in the bottom-left corner of, the open object pane., , Fig 22, , •, , Type the new information into the field., , •, , Click outside of the record row to apply the change., , To edit a record using Find and Replace:, •, , Click the Find command in the Find group on the, Ribbon., , Fig 23, Copa 12258023, , •, , Click the cell containing the information that must be, edited. A pencil icon appears to indicate edit mode., Copa 12258022, , •, , Copa 12258019, , Fig 19, , •, , Type data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , •, , The Find and Replace dialog box opens., , Fig 24, , •, , Copa 12258024, , To add records with the New Record command:, Click the New Record command in the Records group, in the Ribbon., Copa 12258020, , Fig 20, , •, , Tell Access what to find by typing it into the Find What:, area., , •, , Type the replace term in the Replace With: area., , •, , Tell Access where to look with the Look In: drop-down, list. The first choice in the drop-down list is the field, you were last in within the table., , Editing records in tables, , •, , Sometimes it is necessary to edit records in the database., Like with every other task in Access 2007, this can be, done several different ways., , Tell Access what to Match: Any part of the field, the, whole field, or just the start of the field., , •, , Tell Access how to Search: Up finds records above, the cursor, Down finds records below the cursor, and, All searches all records., , •, , Click one of the action options:, , -, , Find Next will find the next instance of the word, in the table., , •, , Type the data into the appropriate fields., , •, , Hit the Enter or the Tab key to move to the next field., , To edit a record directly:, •, , Scroll through the records, or use the navigation, buttons on the navigation bar to find the record to, edit., , 160, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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-, , Replace will put the new word into the table, overwriting, what is currently there., , -, , Cancel stops the editing process., , CAUTION: DO NOT use Replace All because it will, overwrite every instance of the Find term in the table,, which can have a serious impact on your data., To copy and paste a Record:, •, , Select the record you want to copy. Right-click, then, select Copy., , •, , Select the new record row. Right-click and select Paste., The record information appears with a new record ID, number., , To delete a record:, •, , Select the record you want to delete, then right-click, and select Delete Record., , •, , A dialog box appears, telling you the action cannot, be undone and asking if you are sure you want to, delete the record., , Let's say one of your database users has entered an order, date of January 4, 2008, in the month/date/year format as, 01/04/2008. Another user has entered an order placed on, that same date in the day/month/year format as 04/01/, 2008. If the database is tracking all sales for the month of, January 2008, it may not show both orders as placed in, January, even though both were placed on the same date., Access 2007 allows you to set field properties and data, validation rules to force the person entering data to, follow a specific format., Data types and validation rules, Data validation begins when data types are set during, the process of building tables and fields. For example, if, a field data type had been set to Currency and a text, value is entered in that table field during data entry,, Access will not accept an invalid format and will display a, validation error, like the one below., , Fig 27, , There may be other records that rely on the record you, are trying to delete. DO NOT delete a record without, knowing how it will impact the rest of your database., Fig 26, , Copa 12258027, , Copa 12258025, , Fig 25, , Data validation is accomplished by setting data validation, rules and other field properties for various fields., To set data validation rules:, •, , In Design view, highlight the field that requires a, validation rule., , •, , In the Field Properties section at the bottom half of, the window, set your validation rule using, theExpression Builder. The Expression Builder offers, common syntax to set up a data validation rule., , When you delete a record, the record number is, permanently deleted from the database table. If you, delete the last record from a table and then add a new, record, your new record numbers will appear to be out of, sequence., Data validation, Data validation is an important database concept. It is, the process by which Access tests the data that is being, entered into the database to make sure it is in an, acceptable-or valid-format., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258028, , Copa 12258026, , Fig 28, , 161
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The image below shows the resulting error message, users would see when the Category validation rule has, been broken., , Fig 29, , Validation rules work most easily with numerical fields., Rules for text fields require you to enclose each, acceptable value inside its own quotation marks,, separating them with Or, as seen above., , Copa 12258031, , Copa 12258029, , Fig 31, , Using field properties to ensure data integrity, Another way to ensure data integrity is by setting field, properties such as Field Size, Format, and Required., •, , Validation text is a specialized error message you can, set to have Access tell the user entering data the specific, way you want that person to enter it., , Field Size can be set to hold a specific number of, characters, up to as many as 255 for text fields. If, you were using a text field to hold the two-letter state, postal abbreviation, the field size could be set to 2 to, ensure no one enters a full state name into this field., , •, , To set the validation text, enter the error message exactly, as you want it to appear to users in the row directly, beneath the Validation Rule row in the Field Properties, section of Design view. For the validation rule we set for, Category, you'd set the validation text like this:, , The Format field property can be set to display text, or numbers in a standardized way. For example, text, can be set to show as all uppercase, and numbers, can be set to show scientific numbers, percentages,, or decimals., , •, , Set the Required property to Yes if you want users, entering data to be required to enter something in, the field. Choose No if users are allowed to leave the, field blank., , Validation text, , Fig 30, , Copa 12258030, , These are just some ways Access helps you ensure data, being entered into your database is valid., , 162, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.9.62 to 1.9.66, COPA - Database Management Systems, Forms, quires, and reports in access, Objectives : At the end of this lesson you shall be able to, • explain database relationship and forms, • explain quires and reports in as access, In a relational database (Access), the data in one table is, related to the data in other tables. In general, tables can, be related in one of three different ways: one-to-one, oneto-many or many-to-many. The relationship is used to, cross reference information between tables., , Defining relationships, , One to One, , •, , The kind of relationship that Microsoft Access creates, depends on how the related fields are defined:, , •, , A one-to-many relationship is created if only one of, the related fields is a primary key or has a, , •, , A one-to-one relationship is created if both of the, related fields are primary keys or have unique, indexes., , •, , A many-to-many relationship is really two one-tomany relationships with a third table whose primary, key consists of two fields the foreign keys from the, two other tables., , In a one-to-one relationship each record in one table, has at most one related record in another table., In a one-to-one relationship, each record in Table A can, have only one matching record in Table B, and each, record in Table B can have only one matching record in, Table A. This type of relationship is not common, because, most information related in this way would be in one, table. You might use a one-to-one relationship to divide, a table with many fields, to isolate part of a table for, security reasons, or to store information that applies only, to a subset of the main table., , You define a relationship by adding the tables that you, want to relate to the Relationships window, and then, dragging the key field from one table and dropping it on, the key field in the other table., , One to Many, , move a table that appears in the relationship map:, , A one-to-many relationship, often referred to as a, "master-detail" or "parent-child" relationship., , •, , Place your mouse over the table you want to move., , •, , Hold down the left mouse button, then drag the table, to a new location., , •, , Release the mouse button to drop the table in its new, place., , Many to Many, In a many-to-many relationship, a record in Table A can, have many matching records in Table B, and a record in, Table B can have many matching records in Table A., This type of relationship is only possible by defining a, third table (called a junction table) whose primary key, consists of two fields the foreign keys from both Tables, A and B. A many-to-many relationship is really two oneto-many relationships with a third table., , Understanding the relationship map, The relationship map lists all of the tables that were, selected to relate, as well as all of the fields that were, previously set up for that table. Notice that the first field, has a key icon next to it. This is the primary key for the, table., , Fig 32, , A many-to-many relationship means that for each record, in one table there can be many records in another table, and for each record in the second table there can be, many in the first., , Copa 12258032, , A one-to-many relationship is the most common type of, relationship. In a one-to-many relationship, a record in, Table A can have many matching records in Table B, but, a record in Table B has only one matching record in Table, A., , Many-to-many relationships can not be directly, represented in relational database programs and have, to be built by using two or more one-to-many, relationships., , Copyright @ NIMI Not to be Republished, , 163
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Primary and foreign keys, , Bound Forms, , A primary key is the first field in each table of the, database. You may recall that this field auto-numbers, by default, so every record in the table has its own unique, number to identify it. Access uses this number to quickly, pull information together when you run queries or reports,, which are covered later., , •, , Let us now understand what Bound Forms are ?, , •, , Bound forms are connected to some underlying data, source such as a table, query, or SQL statement., , •, , Bound forms are what people typically think of when, they think of the purpose of a form., , In the example above, the primary key for the Customers, table is Customer ID, the primary key for the Orders, table is Order ID, and the primary key for the Books, table is Book ID., , •, , Forms are to be filled out or used to enter or edit data, in a database., , •, , A foreign key is a field that is the primary field in its own, table but that shows up in another table. If you look closely, at the Orders table, the fields Customer ID and Book ID, appear there, as well as in their own respective tables., These fields are the primary key in their own tables, but, in the Orders table, they are considered foreign keys., , Examples of bound forms will typically be what users, use to enter, view or edit data in a database., , Unbound Forms, , Copa 12258033, , Fig 33, , Forms, A form is a database object that you can use to enter,, edit, or display data from a table or a query. You can use, forms to control access to data, such as which fields of, data are displayed. For example, certain users may not, need to see all of the fields in a table. Providing those, users with a form that contains just the necessary fields, makes it easier for them to use the database., , Let us look into Unbound Forms:, •, , These forms are not connected to an underlying, record or data source., , •, , Unbound forms could be dialog boxes, switch boards,, or navigation forms., , •, , In other words, unbound forms are typically used to, navigate or interact with the database at large, as, opposed to the data itself., , Types of Bound Forms, There are many types of bound forms you can create in, Access. Let us understand the types ?, Single Item Form, This is the most popular one and this is where the records, are displayed - one record at a time., Multiple Item Form, This displays multiple records at a time from that bound, data source., , create a form with a single click,, , Split Form, , 1. Open the table or query upon which you want to base, theform., , The form is divided into halves, either vertically or, horizontally. One half displays a single item or record,, and the other half displays a list or provides a datasheet, view of multiple records from the underlying data source., , 2. To create a form on which all fields from the underlying, table or query are placed, displaying one record at a, time, on the Create tab, clickForm., Copa 12258034, , Fig 34, , Forms in Access are like display cases in stores that, make it easier to view or get the items that you want., Since forms are objects through which you or other users, can add, edit, or display the data stored in your Access, desktop database, the design of your form is an important, aspect. There's a lot you can do design-wise with forms, in Microsoft Access. You can create two basic types of, forms -, , Bound forms, , -, , Unbound forms, , 164, , Form Controls, Every object on a form or report is a control and has its, own set of properties (displayed in the Property list) that, determine the characteristics of the data it contains., Some controls are linked to fields in the underlying table, or query and some are merely text or graphical objects, not related to any data source. Two of the most commonly, used controls in a form or report are text boxes and labels., 1) Label: displays unchanging or informational text often, times as headings or titles. Labels do not come from a, source in the database such as a field or expression., This is called an unbound control because it is not bound, to any data source., 2) Text Box: displays data as text and is abound control.A, bound control displaysinformation that is stored in a field, from the data Text boxes are used to display, enter, and, update values from fields in your database., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Form Sections, , Item Total:[Quantity]*[Price], , Forms consist of header, footer, and detail sections. In, forms, there are two types of headers/footers. Form, headers and footers are visible on every page of the, form. Page headers/footers only appear on a printed copy, of a form. There are never visible in Form View., Information about individual records appears in the detail, sections., , Use the Expression Builder to create calculated or, concatenated fields, , Copa 12258035, , Fig 35, , Sizing Sections, Adjust the size of the area for any of the sections, (headers, footers, detail), by dragging the horizontal, border for that section with your mouse. To adjust line, spacing in the detail section, drag the Detail border. There, is no other line spacing control., Working with Queries, Queries are questions you ask of your database. They, allow you to select certain fields out of a table, or pull, together data from various related tables and display it, together. Queries can be used to perform calculations,, and to edit the data in your tables. Queries can also form, the basis of forms and reports., Query Results, •, , •, , If a query contains fields from two or more related, tables, the results will only include records that have, related records in all the tables. (In other words, in, the query shown above, customers without records, in the Orders table will not appear in the query results.), To display such records, use an outer join (see page, 6) in your query., , You can simplify the process of creating concatenated, fields and other expressions with the Expression Builder., Create a blank column in your query grid and then click, the Builder button in the Query Setup group on the Query, Design Ribbon. The Expression Builder opens., Type the expression in the large box at the top. One, advantage is that you have way more room to type and, see your expression than you have at the top of a query, grid column!, A second advantage is that you can add fields to the, expression by double clicking them in the Expression, Categories column rather than by typing them. This, removes the possibility of typos., Fig 36, , WARNING! Any change you make in a query (adding,, deleting or editing data) WILL BE CHANGED IN THE, TABLES TOO!!!, , Sort query results, , Copa 12258036, , In Design View, click the Sort row in the column you, wish to sort by. A dropdown arrow appears; choose, Ascending or Descending. If you sort by more than one, column, the sorts will be done left-to-right., Create a concatenated field in a query, Concatenated fields combine information from two or, more fields into one. Ex: Combine first and last names, into one field, called "FullName". In Design View, click, in a blank column and type the following:, FullName:[FirstName]&" "&[LastName], (Type a space between the two sets of quotation marks,, and use square brackets around the field names.), Create a calculated field in a query, , Specify criteria in a query (Filtering), In Query Design View, click in the criteria row for the, field you want to filter, and type the criteria (ex: type, "OH" in the criteria row of the State field). When you run, the query, only records matching the criteria., , In Design View, click in a blank column and type a, mathematical expression, typing field names in square, brackets. Any of the normal mathematical operators (+ * / ^) can be used. If desired, give the expression a name, as in the sample below. The following expression, calculates a total cost by multiplying quantity times price:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 165
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Using Multiple Criteria, , Fig 37, , Copa 12258037, , You can type criteria in more than one field., •, , Criteria typed on the same line must all be met for a, record to be displayed ("AND" logic). Ex: "OH" in the, state field and "Smith" in the LastName field pulls up, only Ohio-dwelling Smiths., , •, , If criteria are typed on different lines, records matching, any of them will be retrieved ("OR" logic). Ex: "WA", and "OH" on different lines in the State field retrieves, records for both states., , Criteria Ranges, Criteria ranges broaden and customize a search. Type a, criteria range instead of a single value in the Criteria, row of the query grid., Criteria, <, , <=, , Example, , Description and Result, , <14, , Finds records where the field is less than a, certain value., Records will have values under 14., , <= #2/2/2006#, , Finds records where the field is less than, or equal to a, certain value., Records will have dates on or before February, 2, 2006, Note: dates are enclosed between # signs., , >, , >100, , Similar to above: Finds records where the, value is, , >=, , >=100, , greater than 100. The second expression displays, records where the value is greater than or, equal to 100., , =, , ="Diana", , Finds records where the value in the field is Diana., Note: text is enclosed in double quotes., , 166, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Expressions like these may be combined - for example,, a criteria of <49 Or>=100 would return records with, values below 49, or 100 or above, but not ones with, values between 49 and 99.99., Between __ And __, , Between 1 and 4, , Finds records where the field is between, the endpoints., , Is Null, , Is Null, , Finds records where the field is empty., , Is Not Null, , Is Not Null, , Finds records where the field is not empty., , Like, , Like U*, , Finds records where the criteria match parts, of the field., , Like "[U-X]*", , The * wildcard stands for any number of, characters, and, , Like, "*Korea*", , the ?wildcard stands for a single character., , Like "*ina", , The sample criteria will return records where, the field, , Like "Chi??", , 1) starts with U; 2) starts with U, V, W or X,, 3) contains, , Like "*4.99", , the letters 'Korea'; 4) ends in the letters, 'ina' as in ballerina;, 5) has five letters and begins with the letters, 'Chi' as in Chile or China; 6) is a number and, ends in the digits '4.99' as in 24.99., , Create a parameter query, , Fig 38, , Copa 12258038, , Parameters make queries flexible by letting users choose, their own criteria each time they run the query. In the, criteria box, type a phrase in square brackets; Access, will use this phrase to prompt the user for a value. Ex: In, a State field, type [Enter a state]. If the user types CA,, only California records will be retrieved., Specify a range in a parameter query, In the criteria box, type the following:, Between [___] And [____], Inside the brackets, type text telling the user what kind, of information to enter., Inner Joins vs. Outer Joins, Excel normally uses inner joins in its queries. These, queries return only those rows from both tables in the, join that match on the joining field (e.g., customers in, the Customers table with corresponding orders in the, Orders table.), If you need to display all customers, with or without, orders, as well as any available order information, you, need to use an outer join., In the query tray, double click the join line between two, related tables. The Join Properties dialog box will appear:, , Select button 2 or 3 depending on which field's records, you want to display completely., Action Queries, Action queries modify groups of records in one fell swoop., Types of action queries include:, •, , Update Queries (modify all records in a table that, meet specific criteria - ex: change the tax rate for all, Ohio customers from 5.75% to 6%), , •, , Delete Queries (remove records from a table - ex:, delete all customers whose last order date is more, than 2 years ago), , •, , Append Queries (add records to an existing table ex: at the end of the year, add the year's orders to the, end of an archive table), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 167
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•, , Make-table Queries (create a new table - ex: extract a, subset of records into a new table, for a subordinate, who needs Ohio customers only), , Other Specialized Queries, Instructions for creating and running these special query, types can be found in the Access help manual by clicking, the Help button in the upper right corner of the screen, (Internet connection required)., Find Duplicates query: Lets you locate duplicate records, in a table by displaying a field containing duplicate values, alongside other fields for comparison, to help you tell if, the record is really a duplicate., , 168, , Find Unmatched query: Lets you compare two tables, and identify records in one of the tables that have no, corresponding records in the other table., Crosstab query: This is a special type of Totals query, that presents summary information in a compact format, that is similar to a spreadsheet., Union query: Lets you review all of the data that is, returned by several similar select queries together, as a, combined set., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.67 - 1.10.69, , Concepts of network and internet, Objectives : At the end of this lesson you shall be able to, • define computer network and its advantages and disadvantages, • name and explain the types of network and their characteristics, • explain the types of topologies, • state about the cables used for network system, • name and state about the various connectors used in network system, • explain about the hub, modem and internet, • describe about the internet protocols connection sharing (ICS) using windows., Define computer network, , •, , A computer network is an interconnection of various, computer systems located at different places. In, computer network two or more computers are linked, together with a medium and data communication devices, for the purpose of communicating data and sharing, resources. The computer that provides resources to other, computers on a network is known as server. In the, network the individual computers, which access shared, network resources, are known as workstations or nodes., , Workgroup Computing: Workgroup software like, Microsoft BackOffice enables many users to, contribute to a document concurrently. This allows, for interactive teamwork., , •, , Error reduction and improve consistency: One, can reduce errors and improve consistency by having, all staff work from a single source of information, so, that standard versions of manuals and directories can, be made available, and data can be backed up from, a single point on a scheduled basis, ensuring, consistency., , Advantages of Computer Networks, The following are some of the advantages of computer, networks., •, , •, , •, , •, , •, , File Sharing: Networks offer a quick and easy way, to share files directly. Instead of using a disk or USB, key to carry files from one computer or office to, another, you can share files directly using a network., Security: Specific directories can be password, protected to limit access to authorized users. Also,, files and programs on a network can be designated, as "copy inhibit" so you don't have to worry about the, illegal copying of programs., Resource Sharing: All computers in the network can, share resources such as printers, fax machines,, modems, and scanners., Communication: Even outside of the internet, those, on the network can communicate with each other via, electronic mail over the network system. When, connected to the internet, network users can, communicate with people around the world via the, network., Flexible Access: Networks allow their users to access, files from computers throughout the network. This, means that a user can begin work on a project on, one computer and finish up on another. Multiple users, can also collaborate on the same project through the, network., , Network Application Areas, There is a long list of application areas, which can be, benefited by establishing Computer Networks. Few of, the potential applications of Computer Networks are:, 1 Information retrieval systems which search for books,, technical reports, papers and articles on particular, topics, 2 News access machines, which can search past news,, stories or abstracts with given search criteria., 3 Airline reservation, hotel booking, railway-reservation,, car-rental, etc., 4 A writer's aid: a dictionary, thesaurus, phrase, generator, indexed dictionary of quotations, and, encyclopaedias., 5 Stock market information systems which allow, searches for stocks that meet certain criteria,, performance comparisons, moving averages, and, various forecasting techniques., 6 Electronic Fund Transfer (EFT) between banks and via, cheque clearing house., 7 Games of the types that grow or change with various, enthusiasts adding to the complexity or diversity., 8 Electronic Mail Messages Systems (EMMS)., , Copyright @ NIMI Not to be Republished, , 169
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9 Corporate information systems such as marketing, information system, customer information system,, product information system, personnel information, system, etc., , A classification of computer networks can be done to distance as in the table., Interprocess (or), Distance, , 10 Corporate systems of different systems such as Order-Entry System, Centralized Purchasing, Distributed Inventory Control, etc., 11 On-line systems for Investment Advice and Management, Tax Minimization, etc., 12 Resources of interest to a home user., 13 Sports results., 14 Theatre, movies, and community events information., 15 Shopping information, prices, and advertisements., 16 Restaurants; good food guide., 17 Household magazine, recipes, book reviews, film reviews., 18 Holidays, hotels, travel booking., 19 Radio and TV programmes., 20 Medical assistance service., 21 Insurance information., 22 Computer Assisted Instruction (CAI)., , Network Type, , 0 to 1 Km, , Local Area Network (LAN), , 1 Km to 10 Km, , Metropolitan Area, Network (MAN), , 10 Km to 1000 Km, , Wide Area Network (WAN), , Above 1000 Km, , Internet, , Local Area Network (LAN), Networks used to interconnect computers in a single, room, rooms within a building or buildings on one site, are called Local Area Network (LAN). LAN transmits data, with a speed of several megabits per second (106 bits, per second). The transmission medium is normally coaxial cables., LAN (Fig 1) links computers, i.e., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited, geographical area because they must be connected by, a cable, which is quite expensive. People working in LAN, get more capabilities in data processing, work processing and other information exchange compared to standalone computers. Because of this information exchange, most of the business and government organisations are, using LAN., , 23 School homework, quizzes, tests., 24 Message sending service., 25 Directories., 26 Consumer reports., 27 Employment directories and Job opportunities., 28 Tax information and Tax assistance., 29 Journey planning assistance viz. Train, bus, plane, etc., , Major Characteristics of LAN, •, , every computer has the potential to communicate with, any other computers of the network, , •, , high degree of interconnection between computers, , Computer Networks may be classified on the basis of, geographical area in two broad categories., , •, , easy physical connection of computers in a network, , •, , inexpensive medium of data transmission, , 1 Local Area Network (LAN), , •, , high data transmission rate, , 2 Wide Area Network (WAN), , Types of Connection, , 30 Catalogue of Open University and Virtual University, courses., , 3 Metropolitan Area Network (MAN), , 170, , Peer to Peer: Peer to peer is an approach to computer, networking where all computers share equivalent, responsibility for processing data. Peer-to-peer, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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networking (also known simply as peer networking) differs, from client-server networking, where certain devices have, responsibility for providing or "serving" data and other, devices consume or otherwise act as "clients" of those, servers., , who sells the service to the users., 3 A MAN often acts as a high speed network to allow, sharing of regional resources. It is also frequently used, , Client server: The term client-server refers to a popular, model for computer networking that utilizes client and, server devices each designed for specific purposes. The, client-server model can be used on the Internet as well, as LAN., Advantages of LAN, •, , The reliability of network is high because the failure, of one computer in the network does not affect the, functioning for other computers., , •, , Addition of new computer to network is easy., , •, , High rate of data transmission is possible., , •, , Peripheral devices like magnetic disk and printer can, be shared by other computers., , Disadvantages of LAN, If the communication line fails, the entire network system, breaks down., Use of LAN, Followings are the major areas where LAN is normally, used, •, , File transfers and Access, , •, , Word and text processing, , •, , Electronic message handling, , •, , Remote database access, , •, , Personal computing, , •, , Digital voice transmission and storage, , to provide a shared connection to other networks using, a link to a WAN., Campus Area Network (CAN), A Campus Area Network or Corporate Area Network, (CAN) is a network is made up of an interconnection of, local area network within a limited geographical area. A, , Metropolitan Area Network (MAN), A Data network designed for a town or city. In terms of, geographic breadth, MANs are larger than, but smaller, than. MANs (Fig 2) are usually characterized by very, high-speed connections using or other digital media., Characteristic of MAN, 1 The network size falls intermediate between LANs, and WANs. A MAN typically covers an area of, between 5 and 50 km range. Many MANs cover an, area the size of a city, although in some cases MANs, may be as small as a group of buildings., 2 A MAN (like a WAN) is not generally owned by a, single organisation. The MAN, its communications, links and equipment are generally owned by either a, consortium of users or by a network service provider, , CAN (Fig 3) is larger than a local area network but smaller, than a Wide area Network, Wide Area Network (WAN), The term Wide Area Network (Fig 4) is used to describe a, computer network spanning a regional, national or global, area. For example, for a large company the head quarters, might be at Delhi and regional branches at Bombay,, Madras, Bangalore and Calcutta. Here regional centres, are connected to head quarters through WAN. The distance, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 171
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erate nationwide or even worldwide., , between computers connected to WAN is larger. Therefore, the transmission mediums used are normally telephone, lines, microwaves and satellite links., Characteristics of WAN, Followings are the major characteristics of WAN., 1 Communication Facility: For a big company, spanning over different parts of the country the, employees can save long distance phone calls and it, overcomes the time lag in overseas communications., Computer conferencing is another use of WAN where, users communicate with each other through their, computer system., 2 Remote Data Entry: Remote data entry is possible, in WAN. It means sitting at any location you can enter data, update data and query other information of, any computer attached to the WAN but located in, other cities., 3 Centralised Information: In modern computerised, environment you will find that big organisations go, for centralised data storage. This means if the, organisation is spread over many cities, they keep, their important business data in a single place. As, the data are generated at different sites, WAN permits collection of this data from different sites and, save at a single site., , •, , In LAN, the computer terminals and peripheral devices are connected with wires and coaxial cables., In WAN there is no physical connection. Communication is done through telephone lines and satellite links., , •, , Cost of data transmission in LAN is less because the, transmission medium is owned by a single, organisation. In case of WAN the cost of data transmission is very high because the transmission medium used is hired either telephone lines or satellite, links., , •, , The speed of data transmission is much higher in, LAN than in WAN. The transmission speed in LAN, varies from 0.1 to 100 megabits per second. In case, of WAN the speed ranges from 1800 to 9600 bits per, second (bps)., , •, , Few data transmission errors occur in LAN compared, to WAN. It is because in LAN the distance covered is, negligible., , Open Systems Interconnection (OSI), The Open Systems Interconnection (OSI) model is a reference tool for understanding data communications between any two networked systems. It divides the communications processes into seven layers. Each layer both, performs specific functions to support the layers above, it and offers services to the layers below it. The three, lowest layers focus on passing traffic through the network to an end system. The top four layers come into, play in the end system to complete the process., An Overview of the OSI Model (Fig 5), Application Layer (Layer 7): This layer interfaces directly to and performs common application services for, the application processes. The common application services provide semantic conversion between associated, application processes. Examples of common applica-, , Examples of WAN, 1 Ethernet: Ethernet developed by Xerox Corporation, is a famous example of WAN. This network uses coaxial cables for data transmission. Special integrated, circuit chips called controllers are used to connect, equipment to the cable., 2 Arpanet: The Arpanet is another example of WAN. It, was developed at Advanced Research Projects, Agency of U. S. Department. This Network connects, more than 40 universities and institutions throughout, USA and Europe., Difference between LAN and WAN, •, , LAN is restricted to limited geographical area of few, kilometers. But WAN covers great distance and op-, , 172, , tion services include the virtual file, virtual terminal (for, example, Telnet), and"Job transfer and Manipulation protocol" (JTM, standard ISO/IEC 8832), Presentation Layer (Layer 6): The Presentation layer, relieves the Application layer of concern regarding syntactical differences in data representation within the enduser systems. MIME encoding, encryption and similar, manipulation of the presentation of data are done at this, layer. An example of a presentation service would be, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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the conversion of an EBCDIC-coded text file to an ASCIIcoded file., Session Layer (Layer 5): The Session layer provides the, mechanism for managing the dialogue between end-user, application processes. It provides for either duplex or halfduplex operation and establishes check pointing, adjournment, termination, and restart procedures. This layer is, responsible for setting up and tearing down TCP/IP sessions., Transport Layer (Layer 4): The purpose of the Transport layer is to provide transparent transfer of data between end users, thus relieving the upper layers from, any concern with providing reliable and cost-effective, data transfer. The transport layer controls the reliability, of a given link. Some protocols are state ful and connection oriented. This means that the transport layer can, keep track of the packets and retransmit those that fail., The best known example of a layer 4 protocol is TCP., Network Layer (Layer 3): The Network layer provides, the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer. The Network layer performs network routing, flow control, segmentation/desegmentation, and error control functions., The router operates at this layer - sending data throughout the extended network and making the Internet possible, although there are layer 3 (or IP) switches. This is, a logical addressing scheme - values are chosen by the, network engineer. The addressing scheme is hierarchical., Data Link Layer (Layer 2): The Data link layer provides, the functional and procedural means to transfer data, between network entities and to detect and possibly correct errors that may occur in the Physical layer. The addressing scheme is physical which means that the addresses (MAC) are hard-coded into the network cards at, the time of manufacture. The addressing scheme is flat., Physical Layer (Layer 1): The physical layer defines, all electrical and physical specifications for devices. This, includes the layout of pins, voltages, and cable specifications. Hubs and repeaters are physical-layer devices., The major functions and services performed by the physical layer are:, •, , Establishment and termination of a connection to a, communications medium., , •, , Participation in the process whereby the communication resources are effectively shared among multiple users. For example, contention resolution and, flow control., , •, , Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications, , channel. These are signals operating over the physical, cabling - copper and fiber optic, for example. SCSI, operates at this level., Network Topology, The physical topology of a network refers to the configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which is the method used to pass information between workstations., Main Types of Physical Topologies, •, , LINEAR BUS, , •, , STAR, , •, , RING, , •, , TREE, , •, , MESH, , Linear Bus Topology, , A linear bus topology (Fig 6) consists of a main run of, cable with a terminator at each end. All nodes (file server,, workstations, and peripherals) are connected to the linear cable., Advantages of a Linear Bus Topology, •, , Easy to connect a computer or peripheral to a linear, bus., , •, , Requires less cable length than a star topology., , Disadvantages of a Linear Bus Topology, •, , Entire network shuts down if there is a break in the, main cable., , •, , Terminators are required at both ends of the backbone cable., , •, , Difficult to identify the problem if the entire network, shuts down., , •, , Not meant to be used as a stand-alone solution in a, large building., , Star Topology, A star topology (Fig 7) is designed with each node (file, server, workstations, and peripherals) connected directly, to a central network hub, switch, or concentrator, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 173
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Data on a star network passes through the hub, switch, or, concentrator before continuing to its destination. The hub,, switch, or concentrator manages and controls all functions of the network. It also acts as a repeater for the data, flow., This configuration is common with twisted pair cable;, however, it can also be used with coaxial cable or fiber, optic cable., Advantages of a Star Topology, •, , Easy to install and wire., , •, , No disruptions to the network when connecting or, removing devices., , •, , Easy to detect faults and to remove parts., , Disadvantages of a Star Topology, •, , Requires more cable length than a linear topology., , •, , If the hub, switch, or concentrator fails, nodes attached, are disabled., , •, , More expensive than linear bus topologies because, of the cost of the hubs, etc., , •, , There is no need for network server to control the, connectivity between workstations., , •, , Additional components do not affect the performance, of network., , •, , Each computer has equal access to resources., , Disadvantages of Ring Topology, •, , Each packet of data must pass through all the computers between source and destination., , •, , If one workstation or port goes down, the entire network gets affected., , •, , Network is highly dependent on the wire which connects different components., , •, , MAU's and network cards are expensive as compared, to Ethernet cards and hubs., , Tree or Expanded Star, A tree topology (Fig 9) combines characteristics of linear bus and star topologies. It consists of groups of starconfigured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of, an existing network, and enable schools to configure a, network to meet their needs., , Ring Topology, , Advantages of a Tree Topology, , The ring topology (Fig 8) is one which the network is a, loop where data is passed from one workstation to another., , •, , Point-to-point wiring for individual segments., , •, , Supported by several hardware and software vendors., , Advantages of Ring Topology, •, , This is very organized. Each node gets to send the, data when it receives an empty token. This helps to, reduces chances of collision. Also in ring topology all, the traffic flows in only one direction at very high, speed., , 174, , Disadvantages of a Tree Topology, •, , Overall length of each segment is limited by the type, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Disadvantages of Mesh topology, •, , There are high chances of redundancy in many of the, network connections., , •, , Overall cost of this network is way too high as compared to other network topologies., , of cabling used., , •, , •, , If the backbone line breaks, the entire segment goes, down., , Set-up and maintenance of this topology is very difficult. Even administration of the network is tough., , PROTOCOLS, , •, , More difficult to configure and wire than other topologies., , Network Protocol, , Advantages of Mesh topology, , A network protocol defines rules and conventions for, communication between network devices. Protocols for, computer networking all generally use packet switch techniques to send and receive messages in the form of, packets. Network protocols include mechanisms for devices to identify and make connections with each other,, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols, also support message acknowledgement and data compression designed for reliable and/or high-performance, network communication. Hundreds of different computer, network protocols have been developed each designed, for specific purposes and environments., , •, , Parameters of Protocol, , Mesh Topology, A network setup where each of the computers and, network devices are interconnected with one another,, allowing for most transmissions to be distributed, even, if one of the connections go down. This topology is not, commonly used for most computer networks as it is, difficult and expensive to have redundant connection to, every computer. However, this topology is commonly, used for wireless networks (Fig 10)., , •, , •, , Data can be transmitted from different devices, simultaneously. This topology can with stand high, traffic., Even if one of the components fails there is always, an alternative present. So data transfer doesn't get, affected., Expansion and modification in topology can be done, without disrupting other nodes., , 1 Physical cable or transmission media., 2 Number of bits transmitted on the media., 3 When to transmit the data on the network., 4 Volume of data to be transmitted., 5 Interact with a network with different cable type or topology., 6 Ensure that the message has been delivered intact, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 175
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Star Bus, Each computer connects to a, central connection device., , All information passes, through the, central network connection., , Each computer must be, close to the, central device., 100 meters, maximum, cable length., , Add a new, computer by, plugging in a, new cable, from, the, computer to, the connection device., , When one computer goes down,, the rest of the network is unaffected. If the connection device, goes down, then, the network is, down., , More expensive, of, the, simple topologies,, it requires, costly, connection dev i c e ., Usually, cheaper, than a hybrid network., , Uses twisted, pair cable., , To add a, c o m p u t e r,, you, must, shut down, the network, and disconnect, the, cable from, the existing, computers., , If one computer, malfunctions, the, entire network, goes down., , A cheaper, network, s i n c e, there is, usually, one continuous, copper, cable., , Single continuous cable connects the devices., , Cable between the, computers, must be broken to add a, new computer, so the, network is, down until, the new device is back, online., , If there's a break, in the cable or an, error in the network, information, continues to transfer through the, rest of the ring until reaching the, point of the break., This, makes, troubleshooting, easy., , Up to 24, computers, per network., , Requires large, amounts, of, cable. No more, than, 100, meters from, the computer to, the connection, device., , Bus, Single, cable connects everything., , One, computer at a time, sends information. Information goes, along, the, cable and the, computer accesses the information off, the cable., , Connect the, cable from, one, computer to the, next and so, on to the end., , Information, goes in one, direction, around the, ring, and, passes along, the ring until it, reaches the, correct computer., , Computers, are located, close to each, other., , A terminator, is placed at, each end of, the network., , Terminator is, required, at, each end of the, cable., Uses coaxial or, twisted pair cabling., , Ring, S i n g l e, cable configured in a, ring., , 176, , Setup, is, easy. There, is no connector., The ring has, no beginning, and no end., , One of the, more expensive, topologies, due, to, high cable, costs., , Requires more, cabling than, other topologies., Uses twisted, pair., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Hybrid, Mesh, Combines, two or more, different, structures., , Often used, across long, distances. Information, transfer can, happen in different ways,, depending on, the other topologies., , Often created, when, expanding an, existing network. Can, use a variety, of connection, devices., , Connection, devices, make combining different networks, and different, topologies, easy., , and in a proper manner., List of Network Protocols, 1 TCP/IP: Transmission Control Protocol / Internet Protocol is an industry standard protocol widely used. It is, used for inter operating among different types of computers. Almost all types of networks support TCP/IP. It is, the protocol used by the Internet. It uses a 32 - bit addressing scheme., IP Address, IP defines an addressing scheme that is independent of, the underlying physical address (e.g. 48-bit MAC address). IP specifies a unique 32-bit number for each host, on a network., , Troubleshooting is, most difficult in, this topology because of the variety of technologies., , Expens i v e ,, large,, and usually complicated., , Cabling depends on the, types of networks., Can use twisted, pair and coaxial, cable., Also incorporates fiber optic, cabling over, long distances., , FTP is built on a client-server architecture and uses separate control and data connections between the client and, the server. FTP users may authenticate themselves using, a clear-text sign-in protocol, normally in the form of a, username and password, but can connect anonymously, if the server is configured to allow it., For secure transmission that hides (encrypts) the, username and password, and encrypts the content, FTP, is often secured with SSL/TLS ("FTPS"). SSH File Transfer Protocol (SFTP) is sometimes also used instead., 4 SMTP, Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across, Internet Protocol (IP) networks., , This number is known as the Internet Protocol Address,, the IP Address or the Internet Address. These terms are, interchangeable. Each packet sent across the internet, contains the IP address of the source of the packet and, the IP address of its destination., , While electronic mail servers and other mail transfer, agents use SMTP to send and receive mail messages,, user-level client mail applications typically only use, SMTP for sending messages to a mail server for relaying., , 2 UDP - User Datagram Protocol - is a simple OSI transport layer protocol for client/server network applications, based on Internet Protocol (IP). UDP is the main alternative to TCP and one of the oldest network protocols in, existence, introduced in 1980. UDP is often used in, videoconferencing applications or computer games specially tuned for real-time performance., , For receiving messages, client applications usually use, either the Post Office Protocol (POP) or the Internet, Message Access Protocol (IMAP) or a proprietary system (such as Microsoft Exchange or Lotus Notes/, Domino) to access their mail box accounts on a mail, server., 5 Telnet, , 3 FTP: File Transfer Protocol (FTP) is a standard network protocol used to transfer files from one host or to, another host over a TCP-based network, such as the, Internet., , Telnet is a network protocol used on the Internet or local, area networks to provide a bidirectional interactive textoriented communication facility using a virtual terminal, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 177
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connection. User data is interspersed in-band with Telnet, control information in an 8-bitbyte oriented data connection over the Transmission Control Protocol (TCP)., Telnet provided access to a command-line interface (usually, of an operating system) on a remote host. Most, network equipment and operating systems with a TCP/, IP stack support a Telnet service for remote configuration (including systems based on Windows NT). Because, of security issues with Telnet, its use for this purpose, has waned in favour of SSH., 6 HTTP, , Networking Components, •, , Gateway: A device sitting at a network node for, interfacing with another network that uses different, protocols. Works on OSI layers 4 to 7., , •, , Router: A specialized network device that determines, the next network point to which it can forward a data, packet towards the destination of the packet. Unlike, a gateway, it cannot interface different protocols., Works on OSI layer 3., , •, , Switch: A device that allocates traffic from one, network segment to certain lines (intended, destination(s)) which connect the segment to another, network segment. So unlike a hub a switch splits the, network traffic and sends it to different destinations, rather than to all systems on the network. Works on, OSI layer 2., , •, , Bridge: A device that connects multiple network, segments along the data link layer. Works on OSI, layer 2., , •, , Hub: It connects multiple Ethernet segments together, making them act as a single segment. When using a, hub, every attached device shares the same, broadcast domain and the same collision domain., Therefore, only one computer connected to the hub, is able to transmit at a time., , The Hypertext Transfer Protocol (HTTP) is an application, protocol for distributed, collaborative, hypermedia, information systems. HTTP is the foundation of data, communication for the World Wide Web., Hypertext is a multi-linear set of objects, building a, network by using logical links (the so-called hyperlinks), between the nodes (e.g. text or words). HTTP is the, protocol to exchange or transfer hypertext., 7 SSH File Transfer Protocol, In computing, the SSH File Transfer Protocol (also, Secure File Transfer Protocol, Secure FTP, or SFTP) is, a network protocol that provides file access, file transfer,, and file management functionalities over any reliable, data stream., , Depending on the network topology, the hub provides, a basic level 1 OSI model connection among the, network objects (workstations, servers, etc.). It, provides bandwidth which is shared among all the, objects, compared to switches, which provide a, connection between individual nodes., , It was designed by the Internet Engineering Task Force, (IETF) as an extension of the Secure Shell Protocol, (SSH) version 2.0 to provide secure file transfer, capability, but is also intended to be usable with other, protocols., The IETF of the Internet Draft states that even though, this protocol is described in the context of the SSH-2, protocol, it could be used in a number of different, applications, such as secure file transfer over Transport, Layer Security (TLS) and transfer of management, information in VPN applications., This protocol assumes that it is run over a secure, channel, such as SSH, that the server has already, authenticated the client, and that the identity of the client, user is available to the protocol., 8 Post Office Protocol, In computing, the Post Office Protocol (POP) is an, application-layer Internet standard protocol used by local, e-mail clients to retrieve e-mail from a remote server, over a TCP/IP connection. POP and IMAP (Internet, Message Access Protocol) are the two most prevalent, Internet standard protocols for e-mail retrieval., Virtually all modern e-mail clients and servers support, both. The POP protocol has been developed through, several versions, with version 3 (POP3) being the current, standard. Most webmail service providers such as, Hotmail, Gmail and Yahoo! Mail also provide IMAP and, POP3 service., , 178, , •, , Repeater: A device to amplify or regenerate digital, signals received while sending them from one part of, a network into another. Works on OSI layer 1., , •, , Modem (MoDem): A device that modulates an analog, "carrier" signal (such as sound), to encode digital, information, and that also demodulates such a carrier, signal to decode the transmitted information, as a, computer communicating with another computer over, the telephone network, , Types of MODEM, External Modem: This is a modem separated from the, system unit in the computer case. It is connected to the, serial port of the computer by means of a cable. It is, connected to the telephone wall jack by another cable., Internal Modem: An internal modem is a circuit board, (a modem card) that can be added to the system unit of, the computer. It takes one of the expansion slots., Wired Modem / Standard Modem, Most modem’s used today are called standard modems., These modems are usually operated by commands, entered from a microcomputer keyboard. Users control, the functions (dialling, etc.) of a modem through the, keyboard. Modems may use different command, languages to control their functions,, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Wireless Modems: Wireless modems transmit the data, signals through the air instead of by using a cable. They, sometimes are called a radiofrequency modem. This type, of modem is designed to work with cellular technology,, and wireless local area networks. Wireless modems are, not yet perfected, but the technology is rapidly improving., ADSL Modem, Asymmetric Digital Subscriber Line, ADSL (Fig 11) is a, type of DSL broadband communications technology used, for connecting to the Internet. ADSL allows more data to, be sent over existing copper telephone lines POTS, when, compared to traditional modem lines. A special filter, called, a micro filter, is installed on a subscriber's telephone line, to allow both ADSL and regular voice (telephone) services, to be used at the same time. ADSL requires a special, ADSL modem and subscribers must be in close, geographical locations to the provider's central office to, receive ADSL service. Typically this distance is within a, radius of 2 to 2.5 miles. ADSL supports data rates of from, 1.5 to 9 Mbps when receiving data (known as the downstream rate) and from 16 to 640 Kbps when sending data, (known as the up- stream rate)., , Ethernet NICs plug into the system bus of the PC and, include jacks for network cables, while WI-FI NICs contain built-in transmitters / receivers (transceivers). In new, computers, many NICs are now pre-installed by the manufacturer. All NICs feature a speed rating such as 11 Mbps,, 54 Mbps or 100 Mbps that suggest the general performance of the unit., Network Cables Standards, Cable is the medium through which information usually, moves from one network device to another. There are, several types of cable which are commonly used with, LANS. In some cases, a network will utilize only one, type of cable, other networks will use a variety of cable, types. The type of cable chosen for a network is related, to the network's topology, protocol, and size. Understanding the characteristics of different types of cable and, how they relate to other aspects of a network is necessary for the development of a successful network., Cable standards, A wide range of cabling types are been used to run Ethernet, systems. Therefore, different types of cabling standards, are being used for the networks involved in connecting, devices together using different types of cabling system., , Network Interface Card (NIC), NIC (Fig. 12) provides the hardware interface between a, computer and a network. A NIC technically is network, adapter hardware in the form factor of an add-in card such, as a PCI or PCMCIA card. Some NIC cards work with, wired connections while others are wireless. Most NICs, support either wired Ethernet or WI-FI wireless standards., 12, , Coaxial cable (Fig 13) is the kind of copper cable used by, companies between the community antenna and user, homes and businesses. Coaxial cable is sometimes used, by telephone companies from their central office to the, telephone poles near users. It is also widely installed for, use in business and corporation and other types of., Coaxial cable is called "coaxial" because it includes one, physical that carries the signal surrounded (after a layer, of insulation) by another concentric physical channel,, both running along the same axis. The outer channel, serves as a ground. Many of these cables or pairs of, coaxial tubes can be placed in a single outer sheathing, and, with repeaters, can carry information for a great distance., 10BASE-T Cable Standard: 10Base-T is one of the, Ethernet standards for cabling in a network environment., 10BaseT uses a twisted pair cable with a maximum length, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 179
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of 100 meters. Standard 10BaseT operates at 10 Mbps. It, is commonly used in a star topology., 10BASE-FL Cable Standard: 10BaseFL is a fibber optic, cable standard designed to run at 10 Mbps. It is similar, to 10Base-T, though the media type is fibber. For use up, to 2000 meters., 100BASE-TX Cable Standard: 100 Mbps Fast Ethernet, over category 5 twisted pair cable. Maximum cable length, of 100 meters., 100BASE-FX Cable Standard: 100 Mbps Fast Ethernet, standard over fibber cable. Can transmit data up to 2000, meters., 1000BASE-T Cable Standard: Gigabit Ethernet over, twisted pair copper wires. Transmit up to 1000 Mbps., 100 meter maximum cable length. Cat5 or better required, (Cat6 cabling recommended)., 1000BASE-CX Cable Standard: Gigabit Ethernet over, a special copper twinax cable. Up to 25 meters in length., Typically used in a wiring closet or data center as a short, jumper cable., , adjoining wires., The advantage of using twisted pair cables are, •, , It is lighter, thinner and more flexible, , •, , Easy to install, , •, , It is in expensive, , There are two varieties of twisted pair cabling, they are, •, , Unshielded Twisted Pair (UTP), , •, , Shielded Twisted Pair (STP), , Unshielded twisted pair (UTP), Unshielded twisted pair (Fig 14) cabling consists of two, unshielded wires twisted around each other that contain, no shielding. It is commonly used in the telephone wires, and is common for computer networking because of high, flexibility of the cables. It is a plastic connector that looks, like a large telephone-style connector. The standard connector for unshielded twisted pair cabling is RJ-45 connector., , 1000BASE-SX Cable Standard: Gigabit Ethernet using, a short-wavelength laser device over multimode fibber, optic cable. 50 μm core (max 300 meters) or 62.5 μm, core (max 500 meters). 1000Mbps maximum transfer, speed., 1000BASE-LX Cable Standard: Gigabit Ethernet using, long-wavelength laser transmitters over fibber optic, cable. Up to 3,000 meters. Uses single mode fibber and, requires SC connectors for terminating the cable., 10 GBASE-SR Cable Standard: 802.3ae standard. 33, meters for 62.5μm fibber optic cable, 300 meters for, 50μm cables. 10 Gbps (Gigabit per second) transfer rate., 10 GBASE-LR Standard: 10 Gbps transfer rate. 10, kilometres maximum distance. Fibber optic cable., , UTP has five categories of cable standards defined by the, Electronic Industries Association and Telecommunications, Industry Association (commonly known as EIA/TIA). The, five categories of unshielded twisted pair are:, Categories of Unshielded Twisted Pair, , 10 GBASE-ER Standard: 10 Gbps transfer rate. 40, kilometres maximum cable length. Fibber optic cable., , In order to manage the network cabling, you need to be, familiar with the standards that may be used on modern, networks. The categories of the unshielded twisted pair, cable are described below., , Media types, , Category 1, , A cable is a device which contains a number of signal, conductors usually in the form of separate wires. It is the, medium through which information usually moves from, one system to another through the network. There are, several types of cable which are commonly used with, the local area network. In some cases, a network utilizes, only one types of cable, whereas other network uses a, variety of cable types. The type of cable chosen for a, network is related to network topology, protocol and size., , •, , It is a form of UTP that contains two pairs of wire., , •, , CAT is suitable for voice communications but not for, data., , •, , It can carry up to 128 kilobits per second (Kbps) of, data., , •, , Twisted Pair, , It is usually used for telephone wire Data rate - 1, Mbps. This type of wire is not capable of supporting, computer network traffic and is not twisted., , Category 2, , Twisted pair cable is the most common type of network, medium used in LAN today. A transmission media consist, of colour coded pairs of two shielded insulated copper, wires which are arranged in a spiral pattern. The spiral, pattern is an important aspect of twisted - pair cables in, order to minimize cross talk of interference between, , 180, , •, , It contains four wire pairs and can carry up to 4 Mbps, of data., , •, , CAT 2 is rarely found on modern networks., , •, , Category 2 or CAT 2 is capable of transmitting data, up to 4 Mbps. This of cable is seldom used., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Category 3, •, , CAT 3 made up of four twisted - pair wires, each twist, is three times per foot. It is certified to transmit data, up to 10 Mbps., , •, , CAT 3 has typically been used for 10 Mbps Ethernet, or 4 Mbps Token Ring networks., , •, , The CAT 3 cabling is gradually replaced with CAT5 to, accommodate higher throughput., , Category 4, •, , CAT 4 is made up of four twisted-pair wires, specialized to transmit data up to 16 Mbps and is rarely is, used in new installations., , •, , CAT 4 may be used for 16Mbps Token Ring or 10, Mbps Ethernet networks. It is guaranteed for signals, as high as 20 MHz and Provides More protection, against crosstalk and attenuation than CAT1, CAT2,, orCAT 3., , The extra covering in shielded twisted pair wiring protects, the transmission line from leaking into or out of the cable., STP cabling often is used in networks, especially fast, data rate Ethernets., Fiber Optic Cable (Fig 16), , Category 5, •, , CAT 5 is the most popular twisted pair Ethernet cabling designed for high signal integrity which is in common use today., , •, , CAT 5 contains four wire pairs and supports up to, 100 Mbps throughout., , •, , It is the most popular form of UTP for new network, installations and upgrades to Fast Ethernet., , •, , In addition to 100 Mbps Ethernet, CAT 5 wiring can, support other fast networking technologies., , •, , It is popular because it is both affordable and high, speed for today's local area networks Cat 5 cables, are often used in structured cabling for computer, networks such as fast Ethernet., , Category 6, •, , •, , •, , •, , A technology that uses glass (or plastic) threads (fibers), to transmit. A fiber optic cable consists of a bundle of, glass threads, each of which is capable of transmitting, messages on to light waves., Fibre optics has several advantages over traditional metal, lines:, •, , CAT 6 cable was originally designed to support gigabit Ethernet. It is similar to CAT 5 wire, but contains a, physical separator between the four, , Fibre optic cables have a much greater than metal, cables. This means that they can carry more data., , •, , Fibre optic cables are less susceptible than metal, cables to interference., , Twisted copper wires pairs to further reduce the electromagnetic interference., , •, , Fibre optic cables are much thinner and lighter than, metal wires., , It is a twisted-pair cable that contains four wire pairs,, each wrapped in foil insulation. Additional foil insulation covers the bundle of wire pairs, and a fire-resistant plastic sheet covers the second foil layer., , •, , Data can be transmitted (the natural form for data), rather than analogically., , The foil insulation provides excellent resistance to, crosstalk and enables CAT 6 to support at least six, times the throughput supported by regular CAT 5., When the CAT 6 is used as a patch cable, it is usually, terminated in RJ-45 Electrical connectors., , Shield Twisted Pair (Fig 15), A type of copper telephone wiring in which each of the two, copper wires that are twisted together are coated with an, insulating coating that functions as a ground for the wires., , The main disadvantage of fibre optics is that the cables, are expensive to install. In addition, they are more fragile, than wire and are difficult to splice., In addition, telephone companies are steadily replacing, traditional telephone lines with fibre optic cables. In the, future, almost all communications will employ fibre optics., Straight Cable, A straight cable (Fig 17) is to connect different type of, devices. This type of cable will be used most of the time, and can be used to:, , IT & ITES : COPA - (NSQF Level - 4)- Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 181
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Rollover Cable (Fig 19), 19, , 1 Connect a computer to a switch/hub's normal port., 2 Connect a computer to a cable/DSL modem's LAN, port., 3 Connect a router's WAN port to a cable/DSL modem's, LAN port., 4 Connect a router's LAN port to a switch/hub's uplink, port. (Normally used for expanding network), 5 Connect 2 switches/hubs with one of the switch/hub, using an uplink port and the other one using normal, port., If you need to check how straight cable looks like, it's, easy. Both sides (side A and side B) of cable have wire, arrangement with same colour., Crossover Cable, A crossover cable (Fig 18), it's usually used to connect, same type of devices. A crossover cable can be used to:, , 1 Connect 2 computers directly., 2 Connect a router's LAN port to a switch/hub's normal, port. (Normally used for expanding network)., 3 Connect 2 switches/hubs by using normal port in both, switches/hubs., In you need to check how crossover cable looks like,, both side (side A and side B) of cable have wire arrangement with following different colour., , 182, , Rollover cable (also known as Cisco Console Cable or a, Yost Cable) is a type of cable that is often used to connect a computer terminal to a router's port. This cable is, typically flat (and has a light blue colour) to help distinguish it from other types of network cabling. It gets the, name rollover because the pin outs on one end are reversed from the other, as if the wire had been rolled over, and you were viewing it from the other side., Connectors, The media connectors are the physical devices that help, to transfer the data between the systems., RJ11: Registered Jack-11 (Fig 20) a four- or six-wire, used primarily to connect telephone equipment. RJ-11, connectors are also used to connect some types of some, types of Local area network., 20, , RJ45: RJ45 (Fig 21) connectors feature eight pins to which, the wire strands of a cable interface electrically. Standard, RJ-45 pinouts define the arrangement of the individual wires, needed when attaching connectors to a cable., ST: ST stands for Straight Tip (Fig 22) - a quick release, bayonet style developed by AT&T. STs were predominant, in the late 80s and early 90s., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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21, , ST Connectors are among the most commonly used fiber, optic connectors in networking applications. They are cylindrical with twist lock coupling, 2.5mm keyed ferrule. ST, connectors are used both short distance applications and, long line systems., SC: SC stands for Subscriber Connector (Fig 23) - a, general purpose push/pull style Connector developed by, NTT. SC has an advantage in keyed duplexibility to support send/receive channels., SC Connectors are frequently used for newer Network, applications. The SC is a snap-in connector that is widely, used in single mode systems for its performance. The, SC connector is also available in a Duplex configuration., They offer low cost, simplicity, and durability. SC connectors provide for accurate alignment via their ceramic ferrules., The square, snap-in connector latches with a simple, push-pull motion and is keyed. They feature a 2.5mm, Ferrule and molded housing for protection. Typical matched, SC connectors are rated for 1000 mating cycles and have, an Insertion Loss of 0.25 dB., , USB: The USB 2.0 Standard-A type of USB plug is a, flattened rectangle which inserts into a "downstream-port", receptacle on the USB host, or a hub, and carries both, power and data. This plug is frequently seen on cables, that are permanently attached to a device, such as one, connecting a keyboard or mouse to the computer via, USB connection., A Standard-B plug-which has a square shape with bevelled exterior corners-typically plugs into an "upstream, receptacle" on a device that uses a removable cable,, e.g. a printer. A Type B plug delivers power in addition to, carrying data. On some devices, the Type B receptacle, has no data connections, being used solely for accepting, power from the upstream device. This two-connector-type, scheme (A/B) prevents a user from accidentally creating, an Electrical loop., BNC: Bayonet Neill Concelman (Fig 25) connector,, (sometimes erroneously called a British Naval Connector, or Bayonet Nut Connector, a type of connector used with, coaxial cable such as the RG-58 A/U cable used with the, 10Base2. The basic BNC connector is a male type, mounted at each end of a cable., , LC: LC stands for Lucent Connector (Fig 24). The LC is, a small form factor fiber optic connector., The LC Connector uses a 1.25 mm ferrule, half the size of, the ST. Otherwise, it is a standard ceramic Ferrule connector. The LC has good performance and is highly favoured, for single mode., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 183
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This connector has a center pin connected to the center, cable conductor and a metal tube connected to the outer, cable shield. A rotating ring outside the tube locks the, cable to any female connector., BNC T-connectors (used with the 10Base-2 system) are, female devices for connecting two cables to a NIC. A, BNC barrel connector allows connecting two cables together., BNC connectors can also be used to connect some, monitor, which increases the accuracy of the signals sent, from the adapter., Crimping Tool: A crimping tool (Fig 26) is a tool designed to crimp or connect a connector to the end of a, cable. For example, network cables and phone cables, are created using a crimping tool to connect the RJ45 and, RJ11 connectors to the end of the cable. In the picture to, the right, is an example of what a crimping tool looks like., This shows a tool capable of crimping both RJ-11 and RJ45 connectors., , 5 Arrange the untwisted wires in a row, placing them, into the position, running from right to left, in which, they will go into the RJ-45 connector:, •, , Orange with a white stripe, , •, , Orange, , •, , Green with a white stripe, , •, , Blue, , •, , Blue with a white strip, , •, , Green, , •, , Brown with a white stripe, , •, , Brown, , 6 Trim the untwisted wires to a suitable length by holding the RJ-45 connector next to the wires. The insulation on the cable should be just inside the bottom, of the RJ-45 connector. The wires should be trimmed, so that they line up evenly with the top of the RJ-45, connector., •, , Trim the wires in small increments, checking frequently to ensure a correct fit. It's better to cut the, untwisted wires a few times than have to go back, and start all over again because you trimmed off, too much., , 7 Insert the wires into the RJ-45 connector, making sure, that they stay aligned and each color goes into its, appropriate channel. Make sure that each wire goes, all the way to the top of the RJ-45 connector. If you, don't make these checks, you will find that your newly, crimped RJ-45 connector is useless., 8 Use the crimping tool to crimp the RJ-45 connector, to the cable by pressing the jacket and cable into the, connector so that the wedge at the bottom of the connector is pressed into the jacket., Re crimp the cable once more to ensure proper connection., , How to Crimp RJ45, 1 Strip 1 to 2 inches (2.5 to 5.1 cm) of the outer skin at, the end of the cable wire by making a shallow cut in, the skin with a utility knife. Run the knife around the, cable, and the jacket should slide off easily. There will, be 4 pairs of twisted wires exposed, each of them a, different color or colour combination., Orange-white striped and solid orange, Green-white striped and solid green, Blue-white striped and solid blue, Brown-white striped and solid brown, 2 Fold each pair of wires backwards to expose the core, of the cable., 3 Cut off the core and discard., , 9 Follow the instructions above to crimp an RJ-45 connector to the opposite end of the cable, 10 Use a cable tester to assure that your cable is working properly when both ends are crimped., Cable Tester (Fig 27), When connected to an Ethernet cable, a network cable, tester tells if the cable is capable of carrying an Ethernet, signal. If the cable carries the signal, this indicates that, all the circuits are closed, meaning that electric current, can move unimpeded through the wires, and that there, are no short circuits, or unwanted connections, in the wire., Network cable testers vary in complexity and price, but a, basic tester consists of a source of electrical current, a, measuring device that shows if the cable is good, and a, connection between the two, usually the cable itself., , 4 Straighten the twisted wires using 2 pair of tweezers., Grasp a wire beneath a bend with 1 pair of tweezers,, and use the other pair to gently straighten the bend., The straighter your wires, the easier your job will be, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, 184, , Copyright @ NIMI Not to be Republished
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Switch, A Network Switch (Fig 28) is a small hardware device, that joins multiple computers together within one Local, Area Network. Technically, network switches operate at, layer two (Data Link Layer) of the OSI., 28, , Computer networks use Ethernet cables to allow computers in the network to "talk" to each other. An Ethernet, cable has eight wires that are arranged in four pairs. For, current to flow correctly, the wire pairs must be connected, in the proper order., A network cable tester can identify if the wires are paired, correctly. It can also show if there is a break in the insulation, a situation which allows crosstalk between two, wires that should not be connected. The tester can also, tell whether the cable has the proper level of resistance., A network cable tester can be a simple apparatus that, merely identifies whether current flows through the cable,, or it may be a professional-level, complex device that, gives additional information that helps identify the problem., Professional-level network cable testers may not only, tell if an open circuit exists, but may identify where the, break is located. Some also identify the gauge of wire, used and can generate their own signal to test for interference., How to Check with the Tester, , Network switches appear nearly identical to hub, but a, switch generally contains more intelligence (and a slightly, higher price tag) than a hub. Unlike hubs, network switches, are capable of inspecting data packet as they are received,, determining the source and destination device of each, packet, and forwarding them appropriately., By delivering messages only to the connected device intended, a network switch conserves bandwidth and offers, generally better performance than a hub., Availability of Switches, 1 8 Port Switches, 2 16 port switches, 3 24 port switches, 4 32 port switches, Hub: A Hub (Fig 29) is a small, simple, inexpensive, device that joins multiple computers together. Many, network hubs available today support the Ethernet, standard. Other types including USB hubs also exist, but, Ethernet is the type traditionally used in home networking., To network a group of computers using an Ethernet hub,, 29, , 1 Turn on your network cable tester., 2 Plug one end of the Ethernet cable you are trying to, test into the "IN" Ethernet input on the network cable, tester., 3 Plug the other end of your Ethernet cable you are, trying to test into the "OUT" input on the network cable, tester., 4 Press the "Test" button. The network cable tester will, send a signal across the Ethernet cable. If the signal, gets from one end of the cable to the other, a green, light will appear on the device, letting you know that, the test was successful. If the signal does not get, from one end of the cable to the other, a red light will, appear on the device, letting you know that the test, was not successful and that the cable is bad., , first connect an Ethernet cable into the unit, and then, connect the other end of the cable to each computer's, NIC. All Ethernet hubs accept the RJ45 connectors of standard Ethernet cables., Ethernet hubs vary in the speed (network data rate or, bandwidth they support. Some years ago, Ethernet hubs, offered only 10 Kbps rated speeds. Newer types of hubs, offer 100 Mbps Ethernet. Some support both 10 Mbps, and 100 Mbps (so-called dual-speed or 10/100 hubs)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 185
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Routers, Routers (Fig 30) are physical devices that join multiple, wired or wireless networks together. Technically, a wired, or wireless router is a Layer 3 gateway, meaning that the, wired/wireless router connects networks (as gateways do),, and that the router operates at the network layer of the, OSI model., , monthly fee for this equipment that is added to your ISP, account billing., In addition to serving individuals, ISPs also serve large, companies, providing a direct connection from the, company's networks to the Internet. ISPs themselves, are connected to one another through Network Access, Point (NAPs). ISPs may also be called IAPs (Internet, Access Provider)., State Owned ISP's, •, , BSNL - Servicing all of India except Mumbai and, Delhi. Triple-play Broadband Services provided by, ADSL and VDSL. Also providing internet services over, GPRS, 3G, as well as WiMax, , •, , MTNL - Servicing Mumbai and Delhi. Triple-play, Broadband Services provided by ADSL under the "TriBand" brand. Also providing GPRS and 3G internet, services., , Private Owned nationwide ISP's, •, , Airtel - ADSL, GPRS, 3G & 4G LTE, , Home networkers often use an Internet Protocol (IP), wired or wireless router, IP being the most common OSI, network layer protocol. An IP router such as a DSL or, cable modem router joins the home's LAN to the WAN, of the Internet., , •, , Skynet Broadband - Internet Service Provider, , •, , Aircel - GPRS & 3G, , •, , Hathway - Broadband over Cable, , •, , Idea - GPRS & 3G, , Bridges, , •, , MTS India - CDMA/EV-DO, , A bridge (Fig 31) device filters data traffic at a network, boundary. Bridges reduce the amount of traffic on a LAN, by dividing it into two segments., , •, , O-Zone Networks Private Limited - Pan - India Public Wi-Fi hotspot provider, , •, , Reliance Communications - ADSL, GPRS & 3G,, Metro-Ethernet, CDMA/EV-DO, Wimax, , •, , Reliance Industries - LTE (to be launched), , •, , Sify - Broadband over cable, , •, , Tata DoCoMo - GPRS & 3G, , •, , Tata Indicom - ADSL, CDMA/EV-DO, Metro-Ethernet,, WiMax, , •, , Vodafone - GPRS & 3G, , 31, , Bridges operate at the data link layer (Layer 2) of the OSI, model. Bridges inspect incoming traffic and decide whether, to forward or discard it. An Ethernet bridge, for example,, inspects each incoming Ethernet frame - including the, source and destination MAC addresses, and sometimes, the frame size - in making individual forwarding decisions., ISP: Internet Service Provider, it refers to a company that, provides Internet services, including personal and business access to the internet. For a monthly fee, the service provider usually provides a software package,, Username, password and access phone number., Equipped with a modem you can then log on to the, Internet and browse the world wide web and USENET, and send and receive email For broadband access you, typically receive the broadband modem hardware or pay a, , 186, , NSP: Network Service Providers (NSP) is a business or, organization that sells bandwidth or network access by, providing direct Internet backbone access to the Internet, and usually access to its Network Access Point (NAPs)., Network service providers may consist of Telecommunications companies, data carriers, wireless communications providers, Internet service provider, and Cable television operators offering high-speed Internet access., Dial up: Dial-up access is really just like a phone connection, except that the parties at the two ends are computer devices rather than people. Because dial-up access, uses normal telephone lines, the quality of the connection, is not always good and data rate are limited., In the past, the maximum data rate with dial-up access, was 56 Kbps (56,000 bits per second), but new technologies such as ISDN are providing faster rates., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Broadband: The term broadband refers to a telecommunications signal or device of greater Bandwidth (signal processing), in some sense, than another standard or usual, signal or device (and the broader the band, the greater the, capacity for traffic)., Wireless (Wi-Fi): Wireless broadband is high-speed, Internet service via wireless technology. Wireless broadband is available in Internet cafés, local "hot spots" within, many cities, private businesses and many homes., The advantage of wireless broadband is that the computer receiving the Internet signal need not be tethered, by an Ethernet or network cable to the broadband modem or router., , A wireless broadband modem receives the service and, transmits it via radio waves to the immediate surrounding area. Any computer equipped with wireless capacity, within receiving distance can pick up the signal, making, the Internet 'portable.' The most common way to take, advantage of wireless broadband is by using a laptop, computer., Mobile Broadband: The term mobile broadband refers, to high-speed wireless Internet connections and services, designed to be used from arbitrary locations., Cellular networks normally provide broadband connections suitable for mobile access. The technologies in use, today fall into two categories -3G (third generation cell, networks) and 4G (fourth generation)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 187
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.70, , Introduction to TCP/IP, Objectives : At the end of this lesson you shall be able to, • explain TCP/IP, addresses and subnets., Introduction to TCP/IP : TCP and IP were developed by, Department of Defense (DOD) research project to connect, a number different networks designed by different vendors, into a network of networks (the “Internet”). It was initially, usccessful because it delivered a few basic services that, everyone needs (file transfer, electronic mail, remote, logon) across a very large number of client and server, systems. Several computers in a small department can, use TCP/IP (along with other protocols) on a single LAN., The IP component provides routing from the department, to the enterprise network, then to regional networks, and, finally to the global internet. On the battlefield a, communications network will sustain damage, so the, DOD designed TCP/IP to be robust and automatically, recover from any node or phone failure. This design, allows the construction of very large networks with less, central management. However, because of the automatic, recovery, network problems can go undiagnosed and, uncorrected for long periods of time., As with all other communications protocol, TCP/IP is, composed of layers:, IP is responsible for moving packet of data from node to, node. IP forwards each packet based on a four byte, destination address (the IP number). The Internet, authorities assign ranges of numbers to different, organisations. The organisations assign groups of their, numbers to departments. IP operates on gateway, machines that move data from department to organisation, to region and then around the world., TCP is responsible for verifying the correct delivery of, data from client to server. Data can be lost in the, intermediate network. TCP adds support to detect errors, or lost data and to trigger retransmission until the data is, correctly and completely received., Sockets is a name given to the package of subroutines, that provide access to TCP/IP on most systems., The Internet Protocol was developed to create a Network, of Networks (the “Internet”). Individual machines are first, connected to a LAN (Ethernet or Token Ring). TCP/IP, shares the LAN with other users (a Novell file server,, Windows for Workgroups peer systems). One device, provides the TCP/IP connection between the LAN and, the rest of the world. (Refer Fig 1), To insure that all types of systems from all vendors can, communicate, TCP/IP is absolutely standardised on the, LAN. However, larger networks based on long distances, and phone lines are more volatile. In US, many large, corporations would wish to reuse large internal networks, based on IBM’s SNA. In Europe, the national phone, 188, , companies traditionally standardize on X.25. However,, the sudden explosion of high speed microprocessors,, fiber optics and digital phone systems has created a burst, of new options: ISDN, frame relay, FDDI, Asynchronous, Transfer Mode (ATM). New technologies arise and, become obsolete within a few years. With cable TV and, phone companies competing to built the National, Information Superhighway, no single standard can govern, citywide, nationwide, or worldwide communications., The original design of TCP/IP as a Network of Networks, fits nicely within the current technological uncertainty., TCP/IP data can be sent across a LAN or it can be carried, within an internal corporate SNA network or it can, piggyback on the cable TV service. Furthermore,, machines connected to any of these networks can, communicate to any other network through gateways, supplied by the network vendor., Addresses : Each technology has its own convention for, transmission messages between two machines within, the same network. On a LAN, messages are sent between, machines by supplying the six byte unique identifier (the, “MAC” address). In an SNA network, every mahine has, Logical Units with their own network address. DECNET,, Appletalk and Novell IPX all have a scheme for assigning, numbers to each local network and to each workstation, attached to the network., On top of these local or vendor specific network addresses,, TCP/IP assigns a unique number to every workstation in, the world. This “IP number” is a four byte value that, by, convention, is expressed by converting each byte into a, decimal number (0 to 255) and separating the bytes with, a period. For example, a server IP is like 130.132.59.234, Subnets: Although the individual subscribers do not, need to tabulate network numbers or provide explicit, routing, it is convenient for most Class B networks to be, internally manage as much smaller and simpler version, , Copyright @ NIMI Not to be Republished
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of the larger network organisations. It is common to, subdivide the two bytes available for internal assignment, into a one byte department number and a one byte, workstation ID. (Refer Fig 2), , There are three levels of TCP/IP knowledge. Those who, administer a regional or national network must design a, system of long distance phone lines, dedicated routing, devices and very large configuration files. They must, know the IP numbers and physical locations of thousands, of subscriber networks. They must also have a formal, network monitor strategy to detect problems and respond, quickly., Each large company or university that subscribes to the, Internet must have an intermediate level of network, organisation and expertise. A half dozen routers might be, configured to connect several dozen departmental LANs, in several buildings. All traffic outside the organisation, would typically be routed to a single connection to a, regional network provider., However, the end user can install TCP/IP on a personal, computer without any knowledge of either the corporate, or regional network. Three pieces of information are, required:, , The enterprise network is built using commercially, available TCP/IP router boxes. Each router has small, tables with 255 entries to translate the one byte department, number into selection of a destination Ethernet connected, to one of the routers., TCP treats the data as a stream of bytes. It logically, assigns a sequence number to each byte. The TCP, packet has a header that says, in effect, “This packet, starts with byte 379642 and contains 200 bytes of data.”, The receiver can detect missing or incorrectly sequenced, packets. TCP acknowledges data that has been received, and retransmits data that has been lost. The TCP design, means that error recovery is done end-to-end between, the Client and Server machine. There is no formal, standard for tracking problems in the middle of the, network, though each network has adopted some adhoc, tools., , 1 The IP address assigned to this personal computer., 2 The part of the IP address (the subnet mask) that, distinguishes other machines on the same LAN, (messages can be sent to them directly) from machines, in other departments or elsewhere in the world (which, are sent to a router machine), 3 The IP address of the router machine that connects, this LAN to the rest of the world., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.70, , Copyright @ NIMI Not to be Republished, , 189
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IT & ITES, Related Theory for Exercise 1.10.71 to 1.10.72, COPA - Networking Concepts, Transmission media and network components, Objectives :At the end of this lesson you shall be able to, • explain cable media, wireless media and network adapter., Network media : Media are what the message is, transmitted over. Different media have different properties, and are most effectively used in different environments, for different purposes., In computer networking, the medium affects nearly every, aspect of communication. Most important, it determines, how quickly and to whom a computer can talk and how, expensive the process is., , Cable media : Cables have a central conductor that, consists of a wire or fiber surrounded by a plastic jacket., Three types of cable media are twisted-pair, coaxial and, fiber-optic cable. Two types of twisted-pair cable are, used in networks: unshielded (UTP) and shielded (STP)., Table summarizes the characteristics of these types of, cable media, which are discussed in the following sections., , Factor, , UTP, , STP, , Coaxial, , Fiber-optic, , Cost, , Lowest, , Moderate, , Moderate, , Highest, , Installation, , Easy, , Fairly easy, , Fairly easy, , Difficult, , Bandwidth, capacity, , 1- to 155 Mbps, (typically 10 Mbps), , 1- to 155Mbps, (typically 16 Mbps), , Typically, 10 Mbps, , 2 Gbps, (typically 100 Mbps), , Node capacity, per segment, , 2, , 2, , 30 (10base 2), 100 (10 base 5), , 2, , Attenuation, , High (range of, hundreds of meters), , High (range of, hundreds of, meters), , Lower (range of a few, kilometers), , Lowest (range of, tens of kilometers), , EMI, , Most vulnerable to, EMI and, eavesdropping, , Less vulnerable, than UTP but still, vulnerable to EMI, and eavesdropping, , Less vulnerable than, UTP but still vulnerable, to EMI and, eavesdropping, , Not affected by, EMI or, eavesdropping, , Twisted-pair cable : Twisted-pair cable uses one or more, pairs of two twisted copper wires to transmit signals. It is, commonly used as telecommunications cable., When copper wires that are close together conduct, electric signals, there is a tendency for each wire to, produce interference in the other. One wire interferring, with another in this way is called crosstalk. To decrease, the amount of crosstalk and outside interference, the, wires are twisted. Twisting the wires allows the emitted, signals from one wire to cancel out the emitted signals, from the other and protects them from outside noise., Twisted pairs are two color-coded, insulated copper, wires that are twisted around each other. A twisted-pair, cable consists of one or more twisted pairs in a common, jacket. Fig 1 shows a twisted-pair cable., The two types of twisted-pair cable are unshielded and, shielded., 190, , Unshielded twisted-pair cable : Unshielded twistedpair (UTP) cable consists of a number of twisted pairs, with a simple plastic casing. UTP is commonly used in, telephone systems. Fig 2 shows a UTP cable., The Electrical Industries Association (EIA) divides UTP, into different categories by quality grade. The rating for, each category refers to conductor size, electrical characteristics and twists per foot. The following categories are, defined., , Copyright @ NIMI Not to be Republished
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The other side of the punch-down block is wired to a patch, panel. The patch panel provides connectivity through, patch cables to other user devices and connectivity, devices., UTP’s popularity is partly due to the, first usage of the, same in telephone systems. In many cases a network can, be run over the already existing wires installed for the, phone system, at a great savings in installation cost., , – Categories 1 and 2 were originally meant for voice, communication and can support only low data rates,, less than 4 megabits per second (Mbps). These, cannot be used for high-speed data communications., Older telephone networks used Category 1 cable., , Shielded twisted-pair cable : The only difference between shielded twisted pair (STP) and UTP is that STP, cable has a shielded usually aluminium/polyester between, the outer jacket or casing and the wires. Fig 4 shows STP, cable., , – Category 3 is suitable for most computer networks., Some innovations can allow data rates much higher,, but generally Category 3 offers data rates up to 16, Mbps. This category of cable is the kind currently used, in most telephone installations., – Category 4 offers data rates upto 20 Mbps., – Category 5 offers enhancements over Category 3,, such as support for Fast Ethernet, more insulation, and more twists per foot, but Category 5 requires, compatible equipment and more stringent installation., In a Category 5 installation, all media, connectors and, connecting equipment must support Category 5 or, performance will be affected., Data-grade UTP cable (Categories 3,4 and 5) consists of, either four or eight wires. A UTP cable with four wires is, called a two-pair. Network topologies that use UTP, require atleast two-pair wire. You may want to include an, extra pair for future expansion. Fig 3 shows a four-pair, cable., , Because UTP cable was originally used in telephone, systems, UTP installations are often similar to telephone, installations. For a four-pair cable, you need a modular, RJ-45 telephone connector. For a two-pair cable, you, need a modular RJ-11 telephone connector. These, connectors are attached to both ends of a patch cable., One end of the patch cable is then inserted into a, computer or other device, and the other end is inserted, into a wall jack. The wall jack connects the UTP drop, cable (another length of cable) to a punch-down block., , The shield makes STP less vulnerable to EMI because, the shield is electrically grounded. If a shield is grounded, correctly, it tends to prevent signals from getting into or, out of the cable. It is a more reliable cable for LAN, environments. STP was the first twisted-pair cable to be, used in LANs. Although many LANs now use UTP, STP, is still used., Transmission media specifications from IBM and Apple, Computer use STP cable. IBM’s Token Ring network, uses STP and IBM has its own specifications for different, qualities and configurations of STP. A completely different, type of STP is the standard for Apple’s Apple Talk, networks. Networks that confirm to each vendor’s specifications have their own special requirements, including, connector types and limits on cable length., STP has the following characteristics, Cost : Bulk STP is fairly expensive. STP costs more than, UTP and thin coaxial cable but less than thick coaxial or, fiber-optic cabling., Installation : The requirement for special connectors, can make STP more difficult to install than UTP. An, electrical ground must be created with the connectors. To, simplify installation, use standardised and prewired cables., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 191
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Because STP is rigid and thick (up to 1.5 inches in, diameter), it can be difficult to handle., , The following are some coaxial cables commonly used in, networking:, , Bandwidth capacity : With the outside interference, reduced by the shielding, STP can theoretically run at, 500 Mbps for a 100 meter cable length. Few installations, run at data rates higher than 155 Mbps. Currently, most, STP installations have data rates of 16 Mbps., , 50 ohm, RG-8 and RG-11 used for thick ethernet., , Node capacity : Since only two computers can be, connected together by an STP cable, the number of, computers in an STP network is not limited by the cable., Rather, it is limited by the hub or hubs that connect the, cables together. In a Token Ring network, which is the, most common type of STP network, the useful upper limit, is around 200 nodes in a single ring, but it depends on the, type of data traffic in your network. There is a specified, maximum limit of 270, but you will probably never reach, this limit., , PVC and plenum cable : Polyvinyl chloride (PVC) is, commonly used in coaxial cabling because it is a flexible,, inexpensive plastic well suited for use as insulation and, cable jacketing. PVC is often used in the exposed areas, of an office., , Attenuation : STP does not outperform UTP by much in, terms of attenuation. The most common limit is 100, meters., EMI : The biggest different between STP and UTP is the, reduction of EMI. The shielding blocks a considerable, amount of the interference. However, since it is copper, wire, STP still suffers from EMI and is vulnerable to, eavesdropping., Coaxial cable : Coaxial cable commonly called coax, has two conductors that share the same axis. A solid, copper wire or stranded wire runs down the center of the, cable and this wire is surrounded by plastic foam insulation., The form is surrounded by a second conductor, a wire, mesh tube, metallic foil or both. The wire mesh protects, the wire from EMI. It is often called the shield. A tough, plastic jacket forms the cover of the cable, providing, protection and insulation. Fig 5 shows a coaxial cable., , 50 ohm, RG-58 used for thin ethernet., 75 ohm, RG-59 used for cable TV., 93 ohm, RG-62 used for ARCnet., , A plenum is the space between the false ceiling of an, office and the floor above. The air in the plenum circulates, with the air in the rest of the building, and there are strict, fire codes about what can be placed in a plenum, environment., Because PVC gives off poisonous gases when burned,, you cannot use it in a plenum environment. You must use, plenum grade cable instead. Plenum grade cable is, certified to be fire resistant to produce a minimum, amount of smoke. Plenum cable is also used in vertical, runs (walls) without conduit (a tube to hold the cable)., Plenum cable is more expensive and less flexible than, PVC., Fiber-optic cable : Fiber-optic cable transmits light, signals rather than electrical signals. It is enormously, more efficient than the other network transmission media., As soon as it comes down in price (both in terms of the, cable and installation costs) fibre optic will be the choice, for network cabling., Each fiber has an inner core of glass or plastic that, conducts light. The inner core is surrounded by cladding,, a layer of glass that reflects the light back into the core., Each fiber is surrounded by a plastic sheath. The sheath, can be either tight or loose. Fig 6 shows examples of, these two types of fiber optic cables., , Coaxial cable comes in different sizes. It is classified by, size (RG) and by the cable’s resistance to direct or, alternating electric currents (measured in ohms also, called impedance), 192, , Tight configurations completely surround the fibers with, a plastic sheath and sometimes include wires to strengthen, the cable (although these wires are not required). Loose, configurations leave a space between the sheath and the, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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outer jacket, which is filled with a gel or other material., The sheath provides the strength necessary to protect, against breaking or extreme heat or cold. The gel,, strength wires and outer jacket provide extra protection., A cable may contain a single fiber, but often fibers are, bundled together in the center of the cable. Optical fibers, are smaller and lighter than copper wire. One optical fiber, is approximately the same diameter as a human hair., Optical fibers may be multimode or single mode. Single, mode fibers allow a single light path and are typically, used with laser signaling. Single mode fiber can allow, greater bandwidth and cable runs than multimode but is, more expensive. Multimode fibers use multiple light, paths. The physical characteristics of the multimode, fiber make all parts of the signal (those from the various, paths) arrive at the same time, appearing to the receiver, as though they were one pulse. If you want to save, money, look into multimode, since it can be used with, LEDs (light emitting diodes) which are a more affordable, light source than lasers. Fig 7 shows single mode and, multi mode fibers., , bounded media difficult. There are three main types of, wireless media: radio wave, micro wave and infrared., Radio wave transmission systems : Radio waves, have frequencies between 10 kilohertz (KHz) and 1, gigahertz (GHz). The range of the electromagnetic, spectrum between 10 KHz and 1 GHz is called radio, frequency (RF)., Radio wave include the following types., Short wave, Very high frequency (VHF) television and FM radio, Ultra-high frequency (UHF) radio and television, Radio waves can be broadcast omnidirectionally or, directionally. Various kinds of antennas can be used to, broadcast radio signals., Microwave transmission systems : Microwave communication makes use of the lower gigahertz frequencies, of the electromagnetic spectrum. These frequencies,, which are higher than radio frequencies, produce better, throughout and performance. There are two types of, microwave data communication systems: terrestrial and, satellite., Terrestrial microwave : Terrestrial microwave systems, typically use directional parabolic antennas to send and, receive signals in the lower gigahertz range. The signals, are highly focused and the physical path must be line-ofsight. Relay towers are used to extend signals. Terrestrial, microwave systems are typically used when using cabling, is cost prohibitive., Because terrestrial microwave equipment often uses, licensed frequencies, additional costs and time constraints, may be imposed by licensing commissions or government, agencies (the FCC, in the United States)., , Optical fibers are differentiated by core/cladding size, and mode. The size and purity of the core determine the, amount of light that can be transmitted. The following are, the common types of fiber-optic cable., 8.3 micron core/125 micron cladding, single mode, 62.5 micron core/125 micron cladding, multimode, 50 micron core/125 micron cladding, multimode, 100 micron core/140 micron cladding, multimode, A typical LAN installation starts at a computer or network, device that has a fiber-optic network interface and (NIC)., This NIC has an incoming interface and an outgoing, interface. The interfaces are directly connected to fiberoptic cables with special fibre-optic connectors. The, opposite ends of the cables are attached to a connectivity, device or splice center., Wireless media : Wireless media do not use an electrical, or optical conductor. In most cases, the earth’s atmosphere is the physical path for the data. Wireless media is, therefore useful when distance or obstructions make, , Fig 8 shows a microwave system connecting separate, buildings. Smaller terrestrial microwave systems can be, used within a building, as well. Microwave LANs operate, at low power, using small transmitters that communicate, with omnidirectional hubs. Hubs can then be connected, to form an entire network., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 193
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Satellite : Satellite microwave systems transmit signals, between directional parabolic antennas. Like terrestrial, microwave systems, they use low gigahertz frequencies, and must be in line-of-sight. The main difference with, satellite system is that one antenna is on a satellite in, geosynchronous orbit about 50,000 kilometers (22,300, miles) above the earth. Because of this, satellite microwave systems can reach the most remote places on earth, and communicate with mobile devices., Here’s how it usually works: a LAN sends a signal, through cable media to an antenna (commonly known as, a satellite dish), which beams the signal to the satellite in, orbit above the earth. The orbiting antenna then transmits, the signal to the another location on the earth or, if the, destination is on the opposite side of the earth, to another, satellite, which then transmits to a location on earth., Fig 9 shows a transmission being learned from a satellite, dish on earth to an orbiting satellite and then back to, earth., , Because the signal must be transmitted 50,000 kilometers, to the satellite and 50,000 kilometers back to earth,, satellite microwave transmissions take about as long to, cover a few kilometers as they do to span continents., Because the transmission must travel long distances,, satellite microwave systems experience delays between, the transmission of a signal and its reception. These, delays are called propagation delays. Propagation delays, range from .5 to 5 seconds., Infrared transmission systems : Infrared media use, infrared light to transmit signals. LEDs or ILDs transmit, the signals and photodiodes receive the signals. Infrared, media use the tera-hertz range of the electromagnetic, spectrum. The remote controls we use for television,, VCR and CD players use infrared technology to send and, receive signals., , Infrared media use pure light, normally containing only, electromagnetic waves or photons from a small range of, the electromagnetic spectrum. Infrared light is transmitted, either line-of-sight (point-to-point) or broadcast, omnidirectionally, allowing it to reflect off walls and, ceilings. Point-to-point transmission allows for better, data rates, but devices must remain in their locations., Broadcast, on the other hand, allows for more flexibility, but with lower data rates. (Part of the signal strength is, lost with each reflection.), Point-to-point : Infrared beams can be tightly focused, and directed at a specific target. Laser transmitters can, transmit line-of-sight across several thousand meters., One advantage of infrared is that an FCC license is not, required to use it. Also, using point-to-point infrared, media reduces attenuation and makes eavesdropping, difficult. Typical point-to-point infrared computer, equipment is similar to that used for consumer product, with remote controls. Careful alignment of transmitter, and receiver is required. Fig 10 shows how a network, might use point-to-point infrared transmission., , Broadcast : Broadcast infrared systems spread the, signal to cover a wider area and allow reception of the, signal by several receivers. One of the major advantage, is mobility; the workstations or other devices can be, moved more easily than with point-to-point infrared, media. Fig 11 shows how a broadcast infrared system, might be used., Because broadcast infrared signals are not as focussed, as point-to-point, this type of system cannot offer the, same throughout. Broadcast infrared is typically limited, to less than 1 Mbps, making it too slow for most network, needs., Network adapters, sometimes called Network Interface, Cards (NICs) are peripheral cards that plug into the, motherboard of your computer and into a network cable., It is through the network adapter that your computer, communicates on the network. Many newer IBMcompatible computers have built-in networking adapters, for Ethernet., , Because infrared signals are in the terahertz (higherfrequency) range, they have good throughout. Infrared, signals do have a downside: the signals cannot penetrate, Network adapters perform all the functions required to, walls or other objects and they are diluted by strong light, communicate on a network. They convert data from the, sources., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, 194, , Copyright @ NIMI Not to be Republished
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form stored in the computer to the form transmitted or, received (or transceived) on the cable and provide a, physical connection to the network., , How network adapters work : Network adapters receive, the data to be transmitted from the motherboard of your, computer into a small amount of RAM called a buffer., The data in the buffer is moved into a chip that calculates, a checksum value for the chunk and adds address, information, which includes the address of the destination, card and its own address, which indicates where the data, is from. Ethernet adapter addresses are permanently, assigned when the adapter is made at the factory. This, chunk is now referred to as a frame., For example, in Ethernet, the adapter listens for silence, on the network when no other adapters are transmitting., It then begins transmitting the frame one bit at a time,, starting with the address information, then the chunk of, data and then the checksum., , Fig 12 shows how an adapter plugs into a computer and, attaches to a network cable., , The network adapter must still convert the serial bits of, data to the appropriate media in use on the network. For, instance, if the data is being transmitted over optical, fiber, the bits are used to light up an infrared LED (light, emitting diode) or laser diode, which transmits light, pulses down the fiber to the receiving device’s APD, (avalanche photo diode) or photo-transistor. If the data is, being sent over twisted-pair cable, the adapter must, convert the bits of data from the 5-volt logic used in, computers to the differential logic used for digital twistedpair transmission., The circuitry used to perform this media conversion is, called a transceiver. Ethernet is the same no matter what, type of media you use only the transceiver changes., Transceivers can be external devices attached through, the AUI port on an Ethernet adapter, or they can be, internal on the card. Some cards (usually called combo, cards) have more than one type of transceiver built in so, you can use them with your choice of media. AUI, interfaces on Ethernet adapters are not transceiversthey are where you attach a transceiver for the different, media types., , Adapters in Abstract : Your computer software does not, have to be aware of how the network adapter performs its, function because the network driver software handles all, the specifics for your computer. The applications running, on your computer need only address data and hand it to, the adapter card., This is much the way the post office or a parcel delivery, service works. You don’t care about the details of postal, delivery; you simply address your parcel and hand it to, the delivery driver. The postal service manages the, process of delivering it for you., This abstraction allows your computer to use a microwave, radio transmitter just as earily as a fiber-optic network, adapter or an adapter that works over coaxial cable., , Because a network signal travels through copper and, optical fiber at about 66 percent as fast as the speed of, light, there’s a chance that one of two adapters far away, from each other could still be hearing silence when the, other has in fact started transmitting. In this case, they, could transmit simultaneously and garble their data. This, is referred to as a collision., While adapters transmit, they listen to the wire to make, sure the data on the line matches the data being transmitted. As long as it does, everything is fine. If another, adapter has interrupted, the data being, “heard” by the, transmitting network adapter will not match the data, being transmitted. If this happens, the adapter ceases, transmitting and transmits a solid on state instead, which, indicates to all computers that it has detected a collision, and that they should discard the current frame because, it has been corrupted. The network adapter waits a, random amount of time and then again attempts to, transmit the frame., , Everything in your computer remains the same except for, the actual network adapter and the driver software for that, adapter., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 195
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Configuring network adapters : Because network adapters have not been around since computers were invented,, there is no assigned place for cards to be set to. Most, adapter cards require their own interrupt, port address and, upper memory range. PCI motherboards automatically, assign IRQ and post settings to your PCI card, so you don’t, need to worry about it., Unfortunately, network adapters in computers with ISA, buses can conflict with other devices, since no two devices, , 196, , should share the same interrupt or port. No software that, comes with your computer will tell you every interrupt and, port in use unless your computer is already running, Windows NT, so you must be somewhat familiar with the, hardware in your computer or use a program that can probe, for free resources to find one. Many adapters have test, programs that can tell you whether the adapter is working, correctly with the settings you’ve assigned., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73A, , Computer name and workgroup - Client server, Objectives : At the end of this lesson you shall be able to, • define computer name, • define workgroup, • explain client-server model, centralised computing and client computing with central file storage, • explain web server., Computer Name: In network computers are identified by, its IP Address, but a name can also be given to identify it, easily as remembering IP address is difficult comparing, remembering a alphanumeric name., Client-Server : The term Client-Server can describe, hardware, in which case it is referring to network servers, and client computers, or it can refer to a way of organising, software applications and services on a network. Clientserver computing is a powerful way of constructing, programs on a network. In order to describe its advantage, and how it works, we will first describe two alternatives to, client-server computing:, – Centralised computing, – Client computing with central file storage, Centralized computing : Centralized computing originated with mainframe computers and time-sharing. The, principle behind centralized computing is that a central, computer executes a program, such as a database or a, transaction-processing program (for instance, an airline, reservations system or a bank records program) and, remote terminals merely display data on a screen and, convey keyboard data back to the central computer., , Workgroup: In a network computers can be grouped, together by using workgroup feature. Computers in a, particular workgroup will show together when you open a, workgroup. Though a computer of one workgroup can, access other workgroup computers also., Client computers cooperate to ensure that central files, are not corrupted by attempts by several computers to, access them at the same time. When a client computer, needs to perform an operation, the file is transferred to, the client computer to perform the operation. Two, examples of this type of application are networked, database programs that do not use a SQL. (Structured, Query Language) server and any network-aware, application that does not communicate with a special, program executing on the server, such as network, scheduling programs and groupware., , In modern networks, personal computers can perform, the role of dumb terminals. With Windows software, the, PC can appear to the central computer as many terminals,, each virtual terminal accessing different data or, performing a separate transaction on the mainframe., In centralized computing it is the central computer that, does all the work. The data resides on the central, computer and the program executes on the central, computer. The personal computer or dumb terminal only, display screen data and accepts keystrokes for the, central computer to process. Centralized computing, does not fully use the capabilities of today’s powerful, network clients. Fig 1 illustrates centralized computing., Client computing with Central file storage : At the, opposite end of the spectrum from centralized computing, is client computing with central file storage (see Fig 2). In, this way of organizing an application, the client computer, does all the work. A central file server stores, but that is, all., , Copyright @ NIMI Not to be Republished, , 197
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One example of a front end is Microsoft Access when it, is used with a SQL back end. (You can also use Access, without a SQL back end.) Access displays tables in, windows or in forms you can browse. It allows you to, modify and search the tables in an easy-to-use graphical, environment. All the actual data manipulation, however,, occurs on the SQL server. Access translates all the database operations into SQL for the server to perform. The, results of the operations are transmitted back to Access, to display in an intuitive, graphical form., , While it is fully exploits the capabilities of client computers, and provides a richer and more customizable environment, for the user, this type of program can place heavy, demands on the network if the data files in which program, works with are large. It also takes time to transmit data, from the server to the client, process the data, and, transfer it back to the server so other network programs, can access the data., The Client-Server Model : The client-server model, combines the advantages of both the centralized, computing model and the client model of computing. It, does this by performing the operations that are best, executed by a central computer on the file server and, performing those operations that are best done close to, the user on the client computer (see Fig 3). The clientserver model works best when many people need access, to large amounts of data. Simply stated, a client-server, system is any system in which the client computer makes, a request over a network to a server computer that then, satisfies the request., The Client : When you use a client-server system, what, you see is the client, or front end. It presents the interface, to manipulate or search for data. The request you make, by manipulating windows, menu, check boxes and so on,, is translated into a compact form that the client transmits, over the network for the server to perform., , SQL is not limited to database programs such as Microsoft, Access. User programs such as Microsoft Excel can use, SQL to query the back-end data-base server for values, to use in spreadsheet calculations. Program tools allow, custom programs to store and retrieve data in serverbased databases. Query tools provide direct access to, the SQL data., The Server : The server is where data operations in a, client-server system occur. The central computer can, service many client requests quickly and efficiently,, which is the traditional advantage of centralized, computing. The central computer can also provide, enhanced security by performing only authorized, operations on the data., Back-end database software is optimized to perform, searches and sorts and the back-end computer is often, more powerful than the front-end computer., Web server : A web server is a program using the client/, server model and the World Wide Web’s Hyper Text, Transfer Protocol (HTTP) serves the files that form web, pages to web users., Every computer on the internet that contains a web site, must have a web server program. The most popular web, servers are: The Microsoft’s Internet Information Server, (IIS) which comes with the Microsoft’s Windows NT, Server; Netscape Fast Track and Enterprises Servers, and Apache, a web server for Unix-based operating, systems. Other web servers include Novell’s Web Server, for users of its Netware Operating System and IBM’s, family of Lotus Domino Servers. Primarily for IBM’s OS/, 390 and AS/400 customers., Web servers often come as a part of a larger package of, Internet related programs for serving e-mail, downloading, requests for File Transfer Protocol (FTP) files and building, and publishing web pages. Consideration in choosing a, web server include how well it works with the operating, system and other servers, its ability to handle server side, programming and publishing, search engine and site, building tools that may come with it., , 198, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished
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DHCP, Objectives : At the end of this lesson you shall be able to, • define DHCP, • explain DHCP., DHCP: Dynamic Host Control Protocol allows server, computers to distribute dynamic IP address when the, client establish connection to server. The server, maintains a IP address pool and it offer some IP which, is not already alloted to some other client. When client, disconnects from server its IP then becomes free again, and can be given to other client., , superseded by RFC 2131) that allows a server to, dynamically distribute IP addressing and configuration, information to clients. Normally the DHCP server, provides the client with at least this basic information:, , It is dynamic as same client can get different IP in, different times. It is beneficial as requirement of IP, address is less a all the clients are not always connected, to server and its saves the time to allocate IP to each, client manually., Dynamic Host Configuration Protocol (DHCP) is a, standard protocol defined by RFC 1541 (which is, , •, , IP Address, , •, , Subnet Mask, , •, , Default Gateway, , Other information can be provided as well, such as, Domain Name Service (DNS) server addresses and, Windows Internet Name Service (WINS) server, addresses. The system administrator configures the, DHCP server with the options that are parsed out to the, client., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished, , 199
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73B, , Concept of proxy server, Objectives : At the end of this lesson you shall be able to, • explain the meaning of proxy server, • explain common connection point, • explain packet filtering, domain filtering and control user access by service, • explain logging and web publising., What is a proxy server? To be a “proxy” means to act on, behalf of another. This is exactly what a proxy server does;, it acts on behalf of its proxy clients to interact with other, servers. You could say that a proxy server is a “mediator”, for computer communications., Placing a proxy server on your network gives you several, advantages, including security enhancements, coaching, enhancements and greater control over your network, users. The advantages of using Microsoft Proxy Server, (MPS) is listed below:, – Common connection point, – Caching, – Packet filtering, – Domain filtering, – Control user access by service, – Logging, – Web publishing, Common connection point : MPS was designed to, connect two networks, rather like a gateway. Typically,, MPS connects an internal network and the Internet. This, configuration gives the internal computers a common, connection point to the Internet-through MPS., When used to provide a common connection, MPS lets, clients share a single connection to the Internet. Instead of, giving each user on a Local Area Network (LAN) a separate, modem, phone line and dial-up account to the Internet,, MPS can function as a gateway to the Internet using a, single connection. Instead of using separate standard, phone line connections, users can share a single higherspeed connection through the proxy server. The net effect, is usually an overall cost savings and reduction in administrative overhead. One connection is usually cheaper and, easier to maintain than several separate connections., Caching : Since you can use MPS as a common connection point to the Internet, you can also use it to cache, frequently accessed resources. MPS allocates a portion of, the server’s hard disk space to store frequently accessed, objects., Caching can either be passive or active. Passive caching, just stores objects as they are requested so the cache is, updated only when users request information. Active, caching directs the server to refresh objects in the cache, automatically., 200, , You can selectively control MPS caching so that you can, limit the size of cached objects, change the expiration, limits (control the freshness of objects) and determine, whether MPS always caches or always excludes from, cache certain content., Caching only works with the Web Proxy Service, in MPS. You will learn more about the Web Proxy, Service later in this chapter., Packet Filtering : To protect internal users from the, outside world (in other words to protect the network from, outsiders), MPS provides packet-filtering services. A packet, filter prevents unauthorized access from the outside by, limiting the available connection points coming into the, network. To that end, packet filters stop various types of, protocols from entering the network., MPS supports both static and dynamix packet filters. A, static filter keeps all traffic of a certain description or type, from passing through MPServer. A dynamic packet filter, automatically determines which type of traffic is allowed in, or out. With a static filter the administrator defines the port,, the protocol and may be the IP address. With a dynamic, filter the administrator just defines the service to be allowed, or filtered., Domain Filtering : MPS also lets you limit the access of, your internal clients to the Internet. You can configure, filters for a single computer, a group of computers or a, domain name. Many companies prefer to have this type of, control over their users because they can block access to, Internet sites that they believe reduce employee productivity or contain offensive material. Some popular examples, of domain filtering are blocking access to Internet game, servers or Web sites that contain pornographic material., You can configure domain filters for a specific IP address,, IP address and subnet mask or domain name. IP address, filters prevent users from contacting a single computer., Using the IP address and subnet mask as a filter limits, access to an entire group (a subnet) of computers. Domain, name filters can apply to an entire Web site or to subsections of that site., Control user access by Protocol or Service : You can, also selectively enable and disable ports, services and, protocols through MPS. MPS lets you control access to, Internet services at the user level. You can also enable or, restrict access to protocols on a user or group basis. Many, protocols are predefined in the default MPS configuration., , Copyright @ NIMI Not to be Republished
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If the protocol or service you would like to enable or disable, is not defined in the MPS property sheets, you can create, a new sheet. you can define a protocol by TCP (Transmission Control Protocol) or UDP (User Datagram Protocol), port number or range. This gives you the ability to control, access by port., Logging : Because all traffic between networks passes, through MPS, MPS has the unique opportunity to log and, track communication. You can track the information your, internal clients get from other networks or the Internet and, monitor inbound communication. You can use this information to help you secure your internal network from attack, and unauthorized access. Plus, you can monitor where, your users spend their time on the Internet and what, information they are downloading., Web publishing : MPS can also act as a Web server., MPS can service requests from cache on behalf of a Web, server, pass requests to the Web server on the local, system or pass requests to another Web server on the, internal network. The terms “reverse proxying” and “reverse, hosting” describe the Web Publishing services that MPS, provides., As a reverse proxy, MPS listens to incoming Web requests, for a single Web server on the local network. The incoming, requests are simply forwarded to another Web server. Web, hosting requires more work on the part of MPS. As a, reverse host, MPS can send requests to one of many Web, servers. In this case, MPS responds as if the entire site, were contained locally, even though the actual data may be, coming from several different Web servers., The main difference between reverse proxying and reverse, hosting is that in performing reverse proxying, MPS forwards all requests to the Web server. In performing reverse, hosting, MPS selectively forwards requests to multiple, Web servers on the internal network. In reverse hosting, the, Microsoft Proxy Server routes an external request for a, resource (that specifies an Internet domain name) to one, or more internal Web servers. For instance, requests for, http://www.hudlogic.com/bios might be routed to an internal server named “business” (http://business), while requests for http://www.hudlogic.com/pictures could be sent, to a different Web server named “server1” (http://server1)., Services : Microsoft Proxy Server 2.0 supports Hypertext, Transfer Protocol (HTTP) version 1.1, Windows Sockets, version 1.1, SOCKS version 4.3a and Secure Sockets, Layer (SSL) 3.0. The MPS services that provide this, support are the Web Proxy service, WinSock Proxy, service and the SOCKS Proxy service, respectively., , Web Proxy Service : The Web Proxy service provides, support for HTTP (a.k.a.Web publishing), FTP, Gopher and, secure (SSL) communications. The Web Proxy service, works with any CERN-compliant Web browser, such as, Internet Explorer or Netscape Navigator. Because the Web, Proxy supports only these widely adopted Internet standard communication methods, it isn’t operating system, dependent. Clients running Unix, Macintosh or Windows, operating systems can communicate with the Web Proxy, service as long as they’re configured with a CERN-complaint Web browser., Any operating system using a CERN-compliant, Web browser can communicate through the Web, Proxy server, regardless of its underlying operating system., WinSock Proxy Service : The WinSock Proxy service, supports Microsoft Windows operating systems using, Windows Sockets. This supprt is available for both Transmission Control Protocol/internet Protocol (TCP/IP) and, Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocols. The WinSock Proxy service, applies mainly to Windows clients including Windows 3.x,, windows 95 and Windows NT., Windows Sockets is an interprocess communication, mechanism derived from the Berkeley Sockets interface, (originally designed for Unix systems). The Sockets interface was extended to support Windows-based clients, running Microsoft implementations of TCP/IP. The name, given to this Sockets interface for Windows was WinSock, (for Windows Sockets)., The WinSock Proxy Service doesn’t support 16-bt, IPX/SPX clients such as the Windows 3.x 16-bit, Netware clients., SOCKS Proxy Service : The SOCKS Proxy service, supports SOCKS version 4.3a client applications such as, FTP, Gopher and Telnet. Operating systems like Macintosh and Unix can run SOCKS 4.3a and access the, SOCKS Proxy service when communicating through the, Microsoft Proxy Server. One limitation of the SOCKS proxy, service on MPS is that it does not support UDP-based, protocols., UDP-based protocols aren’t supported through, the SOCKS Proxy service, but the WinSock Proxy, service does support UDP for Windows clients., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73B, , Copyright @ NIMI Not to be Republished, , 201
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.74, , Video conferencing, Objectives: At the end of this lesson you shall be able to, • define video conferencing, • list the advantages of video conferencing, • list the disadvantages of video conferencing., Video Conferencing, , and eye contact in these. Video conferencing allows, users to successfully convey, creating essential social bonds and shared understandings., , Definition: Videoconferencing is the conduct of a conference by a set of telecommunication technologies, which allow two or more remotely located teams to communicate by simultaneous two-way video and audio, transmissions. It has also been called 'visual collaboration' and is a type of groupware., , 5 Increased Productivity, , Video conferencing is a very useful technique to cut down, various costs as well as travel time when meetings and, conferences are concerned.Video conferencing connects, individuals in real time through audio and video communication over broadband networks. It enables visual, meetings and collaboration on digital documents and, shared presentations. New technologies allow participants to connect remotely over a network through multiple devices like laptops, desktops, smartphones and, tablets., , 7, , Advantages, 1 Significant Travel Savings, 2 Not only is video conferencing a direct replacement, for many in-person business trips, but because there, is virtually no cost to add additional key employees, to a virtual meeting, it is a cost effective solution., , 6 Important meetings are shorter and more effective., But it is a well-known fact that many meetings take, longer than the necessary time of the participants., Video conferencing users can save a minimum of, two hours a week with the technology. The interactivity, of group collaboration and document sharing greatly, increases productivity., Conferencing Quality, , 8 The present day state-of-the-art technology delivers, excellent, reliable audio and video quality, making, conferencing very effective and interesting too., Disadvantages, 1 Absence of Physical Presence, 2 Initial installation costs, 3 Not yet popular with a large size of users., , 3 Improved Communication, 4 Audio conferencing and e-mail may be used for communication but there is a lack of visual connection, , 202, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.75, , Network security, Objectives: At the end of this lesson you shall be able to, • define network security, • explain network security concepts., Network security consists of the provisions and policies, adopted by a network administrator to prevent and, monitor unauthorizedaccess, misuse, modification, or, denial of a computer network and network-accessible, resources. Network security involves the authorization, of access to data in a network, which is controlled by the, network administrator., Network security concepts, Network security refers to any activities designed to, protect your network. Specifically, these activities protect, the usability, reliability, integrity, and safety of your, network and data. Effective network security targets a, variety of threats and stops them from entering or, spreading on your network., Network security starts with authenticating, commonly, with a username and a password. Since this requires, just one detail authenticating the user name -i.e. the, password- this is sometimes termed one-factor, authentication. With two-factor authentication, something, the user needs a 'dongle', an ATM card, or a mobile, phone, and with three-factor authentication, something, the user needs a fingerprint or retinal scan., Once authenticated, a firewall decides what services, are allowed to be accessed by the network users. Though, effective to prevent unauthorized access, this component, may fail to check potentially harmful content such as, computer worms or Trojans being transmitted over the, network., Anti-virus software or an intrusion prevention system, (IPS) helps detect and inhibit the action of such malware., Encrypting the communication between two hosts using, a network helps maintain privacy., Surveillance and early-warning toolssometimes referred, to as Honeypots can be employed., Hhoneypot is a trap set to detect, deflect, or, in some, manner, counteract attempts at unauthorized use of, information systems. Generally, a honeypot consists of, a computer, data, or a network site that appears to be, part of a network, but is actually isolated and monitored,, and which seems to contain information or a resource of, value to attackers. This is similar to the police baiting a, criminal and then conducting undercover surveillance., , The Foundations of Security, Security relies on the following elements:, •, , Authentication, , Authentication addresses the question: who are you? It is, the process of uniquely identifying the clients of your, applications and services. These might be end users,, other services, processes, or computers. In security, parlance, authenticated clients are referred to as, principals., •, , Authorization, , Authorization addresses the question: what can you do?, It is the process that governs the resources and, operations that the authenticated client is permitted to, access. Resources include files, databases, tables, rows,, and so on, together with system-level resources such as, registry keys and configuration data. Operations include, performing transactions such as purchasing a product,, transferring money from one account to another, or, increasing a customer's credit rating., •, , Auditing, , Effective auditing and logging is the key to nonrepudiation. Non-repudiation guarantees that a user, cannot deny performing an operation or initiating a, transaction. For example, in an e-commerce system,, non-repudiation mechanisms are required to make sure, that a consumer cannot deny ordering 100 copies of a, particular book., •, , Confidentiality, , Confidentiality, also referred to as privacy, is the process, of making sure that data remains private and confidential,, and that it cannot be viewed by unauthorized users or, eavesdroppers who monitor the flow of traffic across a, network. Encryption is frequently used to enforce, confidentiality. Access control lists (ACLs) are another, means of enforcing confidentiality., •, , Integrity, , Integrity is the guarantee that data is protected from, accidental or deliberate (malicious) modification. Like, privacy, integrity is a key concern, particularly for data, passed across networks. Integrity for data in transit is, typically provided by using hashing techniques and, message authentication codes., , Copyright @ NIMI Not to be Republished, , 203
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•, , Availability, , How Do You Build a Secure Web Application?, , From a security perspective, availability means that, systems remain available for legitimate users. The goal, for many attackers with denial of service attacks is to, crash an application or to make sure that it is sufficiently, overwhelmed so that other users cannot access the, application.Threats, Vulnerabilities, and Attacks Defined, A threat is any potential occurrence, malicious or, otherwise, that could harm an asset. In other words, a, threat is any bad thing that can happen to your assets., A vulnerability is a weakness that makes a threat, possible. This may be because of poor design,, configuration mistakes, or inappropriate and insecure, coding techniques. Weak input validation is an example, of an application layer vulnerability, which can result in, input attacks., , It is not possible to design and build a secure Web, application until you know your threats. An increasingly, important knowledge needed is about threat modeling., The purpose of threat modeling is to analyze your, application's architecture and design and identify, potentially vulnerable areas that may allow a user,, perhaps mistakenly, or an attacker with malicious intent,, to compromise your system's security., After you know your threats, design with security in mind, by applying proven security principles. You must follow, secure coding techniques to develop secure, robust, and, hack-resilient solutions. The design and development of, application layer software must be supported by a secure, network, host, and application configuration on the, servers where the application software is to be deployed., , An attack is an action that exploits a vulnerability or, enacts a threat. Examples of attacks include sending, malicious input to an application or flooding a network in, an attempt to deny service., , 204, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.75, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.76 & 1.11.77, , E-mail, Objectives : At the end of this lesson you shall be able to, • state the hotmail services offered, • explain MSN outlook express and its tools, • explain popular search engines, • state the FAQs about hotmail., Hotmail: MSN Hotmail is the world’s largest provider of, free Web-based e-mail. Hotmail is based on the premise, that e-mail access should be easy and possible from any, computer connected to the World Wide Web., By adhering to the universal HyperText Transfer Protocol, (HTTP) standard, Hotmail eliminates the disparities that, exist between different e-mail programs. Sending and, receiving e-mail from Hotmail is as easy as going to the, Hotmail web site at http://www.hotmail.com, or by clicking, on the Hotmail link at http://www.msn.com, signing in,, and sending an e-mail message., Hotmail is the web-based e-mail provider, which means, you can send and receive messages from any computer, connected to the Internet. You can use Hotmail from, home, work, school, an Internet cafe, a friend’s house or, any other computer in the world with an Internet connection. Your messages are stored in a central location, so, your Inbox will always be up to date. This is great for, people who use more than one computer, travel frequently, or don’t even own a computer., Advantages of Hotmail, Get a permanent e-mail address: When you create a, Hotmail account, you choose a permanent e-mail address that will never change as long as you continue to, use Hotmail. This is great for people who: Want to switch, Internet Service Providers. Your Hotmail address will be, the same no matter how you access the Internet, so you, don’t have to worry about retrieving messages from your, old address or notifying friends, family and associates of, a new e-mail address. You are free to select any Internet, Service Provider that suits your needs., When you leave town for travel, you may no longer have, access to your ISP’s e-mail account. But with Hotmail,, your friends will always know where to reach you., Your e-mail is private and secure: When you sign up, for Hotmail, you choose your personal ID and password., The only way you can access your account is by using the, password you selected. This means that only you will, have access to your Hotmail account, even if you use a, computer at a public terminal or a friend’s house. Because, the messages in your Hotmail account are stored securely at a central location, you don’t have to worry about, losing important information if something happens to, your computer. Hotmail is strongly committed to keeping, your personal information confidential., , Hotmail is fast and easy to use: Hotmail is recognized, world wide as the best Web-based e-mail service. It is, also stated that ‘while others provide similar services,, none can match Hotmail’s general ease of use’. If everything is fine, it takes less than a minute to get started on, Hotmail and its pages are so worked out to load quickly, knowing that the users time is valuable., Get an additional e-mail account for FREE:Hotmail, offers everyone the opportunity to get a free e-mail, account. Hotmail can offer e-mail accounts for free, because it places banner advertising on some of its, pages. Some Internet Service Providers charge a monthly, fee for additional e-mail accounts. Hotmail lets an, unlimited number of people use a single Internet Service, Provider account and have a free, personal e-mail, account., Keep your personal e-mail separate from your work, e-mail: People who use e-mail for work will find it, convenient to keep their personal messages separate, from their work messages. You can use Hotmail for your, personal correspondence and your company’s e-mail, system only for business messages. Additionally, you, don’t have to store personal e-mail on your company’s, servers. All messages in your Hotmail account are, securely stored in a central location that you access via, the Internet with the password you select., Outlook Express, Microsoft Outlook Express puts the world of online, communication on your desktop. Whether you want to, exchange e-mail with colleagues and friends or join, newsgroups to trade ideas and information. Some of the, tools offered by outlook express are;, Manage multiple mail and news accounts: If you have, several mail or news accounts, you can use them all from, one window. You can also create multiple users, or, identities, for the same computer. Each identity gets its, own mail folders and Address Book. The ability to create, multiple accounts and identities makes it easy for you to, keep work separate from personal mail and also between, individual users., Browse through messages quickly & easily: Using, the message list and preview pane, you can view a list of, messages and read individual messages at the same, time. The Folders list contains mail folders, news servers,, and newsgroups, and you can easily switch between, them. You can also create new folders to organize and, sort messages, and then set up message rules so that, , Copyright @ NIMI Not to be Republished, , 205
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incoming mail that meets your criteria automatically, goes to a specific folder. You can also create your own, views to customize the way you look at your mail., Keep your mail on a server so you can view it from, more than one computer: If your ISP uses an IMAP, mail server for incoming mail, you can read, store, and, organize your messages in folders on the server without, downloading the messages to your computer. That way,, you can view messages from any computer that can, connect to that server., Use the Address Book to store and retrieve e-mail, addresses: You can save names and addresses in your, Address Book automatically by simply replying to a, message or by importing them from other programs, by, typing them in, by adding them from e-mail messages, you receive, or by searching popular Internet directory, services (white pages). The Address Book supports, Lightweight Directory Access Protocol (LDAP) for, accessing Internet directory services., Add a personal signature or stationery to your messages: You can insert essential information into outgoing messages as part of your personal signature, and you, can create multiple signatures to use for different, purposes. For more detailed information, you can include, a business card. To make your messages look more, attractive, you can add stationery patterns and backgrounds, and you can change the color and style of the, text., Send and receive secure messages: You can digitally, sign and encrypt messages by using digital IDs. Digitally, signing your message assures recipients that the message is really from you. Encryption ensures that only, intended recipients can read a message., Find newsgroups that interest you: Looking for a, newsgroup that matches your interests? You can search, for newsgroups that contain keywords or browse through, all of the newsgroups available from your Usenet provider. When you find a newsgroup you want to view, regularly, add it to your Subscribed list so you can find it, again easily., View newsgroup conversations efficiently: You can, view a newsgroup message and all of the responses, without reading an entire message list. When you view, the list of messages, you can expand and collapse, conversations to make it easier to find what interests you., You can also use views to display only the messages you, want to read., Download newsgroup messages for offline reading:, To use your online time efficiently, you can download, messages or entire newsgroups, so you don’t have to be, connected to your ISP to read messages. You can also, download message headers only for offline viewing and, then mark the headers of the messages you want to read;, then the next time you are connected, Outlook Express, downloads the message text. You can also compose, messages offline and send them the next time you, reconnect., 206, , Some important (Top 8 ) recommendations for staying, safe and secure when you’re online are listed below;, – Change your password often. The quick act of changing your password can ensure your e-mail remains, private. In addition,passwords that use both letters, and numbers are harder to break., – Don’t share your password. Most e-mail administrators will not ask for your password. Do not be duped, by malicious e-mails asking you for your password., This is a well-known, although not-too-common trick, designed to fool you into sharing your password. As, a rule, never share it with anyone., – Never open attachments from unknown sources., They may contain what are known as “letterbombs” or, “viruses,” which can damage your PC., – Always remember to sign out when you are done. It’s, quick, easy and may save your account from unwanted trespassers. If you are using a public terminal,, at an internet cafe for example, it is advised that you, close the browser you were using when you are ready, to end your Internet session., – Don’t reply to unsolicited messages (“spam”) mail, or, other harassing or offensive mail. By responding, you, only confirm that you are a person with an active email address who can be plagued with constant, unwanted e-mail solicitations. Instead, forward the, unsolicited message to the customer service, department of the source’s e-mail (usually of a form, similar to, abuse@[implicateddomain].com). To, help control spam, Hotmail provides members with, “filters” for incoming mail. These can easily be set up, to send certain messages (such as those that include, certain words) directly to your online trash can., – Make sure that you are using the most up-to-date, Internet software (e.g. browsers such as Microsoft, Internet Explorer or Netscape Navigator). More recent, versions often offer enhanced security protection., – Always use a secure network. Most corporate networks and Internet service providers are protected by, administrators who watch for potential security problems and act to protect users from “hackers” (malicious users) who may try to steal personal information, that is transferred through the network. Although the, risk is small, use caution when on any unfamiliar, network., – Use stations maintained by sources you trust, or ask, if the Internet terminal you are using is protected, against security break-ins., A SMALL LIST OF Search Engines, Yahoo.com (http://www.Yahoo.com), Search.com (http://search.com), EasySearcher (http://www.easysearcher.com), AltaVista (http://www.altavista.com), Excite (http://www.excite.com), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
Page 726 : Google (http://www.google.com), Hotbot (http://www.hotbot.com), Infoseek (http://www.infoseek.com), Lycos (http://www.lycos.com), WebCrawler (http://www.webcrawler.com), www.all4one.com (This useful tool queries four search, engines at once), , Also, MSN has introduced Preview 2 of MSN Explorer as, an integrated client for MSN services, such as MSN, Hotmail. This client allows you to also store Hotmail, locally on your machine. This too reduces the amount of, storage that you need on hotmail., 2 Can I get Hotmail in different languages?, MSN Hotmail can now be viewed in a variety of languages., , www.askjeeves.com (Insted of entering words to search, for, just type in your question), , You can make the language of a Hotmail session match, the language of the Sign In page used to begin that, session. You have your choice of the following languages: English, French, German, Italian, Japanese,, Portuguese (Brazilian), and Spanish, and more to come., , www.rediff.com (Search for anything), , 3 Can I use Hotmail as a business address?, , www.bigfoot.com (Looking for someone’s email address ? Try here), www.hotbot.com (Useful search engine which helps to, find pictures, video or music), , No. You may not use your Hotmail address as your, primary business address. If, however, you work for a, company with which you have an e-mail address and you, want to use your Hotmail account to send and receive email while away from your computer at work, you are, encouraged to do so., , www.indiainfo.com (Info lets you search the web easily), , Example of Prohibited Use:, , www.yahoo.com (Search engine which is also the most, popular), , You are an individual who runs a business. You and your, employees want to use Hotmail accounts rather than, registering and administering your account through a, paid ISP., , www.av.com (Very powerful search engine which gives, plenty of results), , www.sawaal.com (All your questions answered), , mp3.lycos.com (The place to start if you’re after music, files in the mp3 format), www.metacrawler.com (Metacrawler puts your search, through a host different engines), www.mirago.co.uk (A search engine eith an excellent, selection of shopping links), www.webferret.com (One of the easiest way to search, the web), www.indiatimes.com (The portal’s search engine), www.webcrawler.com (Let the webcrawler spider to do, the searching for you), www.indonet.net (Excellent Indian search engine with, loads of useful search catagories), www.satyamonline.com (On ISP’s site and has good, search options), COMPILED LIST OF INTERESTING FAQ’s about, HOTMAIL, 1 How much e-mail storage space do I get with Hotmail?, Hotmail offers 2MB of storage space. If you do not keep, your account below this limit, Hotmail may remove some, messages, which cannot be recovered., If you need additional storage space, there are a few, options. You can use the latest version of Microsoft, Internet Explorer v5 or above, which includes Outlook, Express, which offers you the ability to store e-mails, locally. You can send a blank e-mail message to,
[email protected] for more information on how to, use the beta (pre-release) process to store Hotmail, messages on your local PC, using Outlook Express., , Example of Allowed Use:, You are a businessperson who travels. You have an, account with your company (yourname@your, company.com). You use your Hotmail account to read, and send solicited messages while you are traveling., Hotmail prohibits account sharing. Since Hotmail is, accessible from everywhere in the world, each individual, is able to sign up for his or her own personal account. You, are encouraged to sign up for an account of your own, to, which only you have access. Sharing an account compromises the privacy and security of your e-mail. Each, Hotmail user must have his or her individual e-mail, account., 4 Is my e-mail really private and secure? (SSL)?, Secure connections (often called SSL, or Secure Sockets Layer) is the industry standard in Web security. It is, used primarily for transmitting sensitive information over, the Internet. When you have a secure connection between, your, browser and a Web site, no one else can easily, access the data that you send across the connection., Hotmail uses SSL to encrypt your sign-in name, and, password, when you log in to give you a high level of, security., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished, , 207
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It is Hotmail’s policy to respect the privacy of its users., Therefore, Hotmail will not monitor, edit, or disclose the, contents of a user’s private communications unless, required to do so by law or in the good faith belief that, such action is necessary to:, – conform to the edicts of the law or comply with, legal process served on Hotmail;, – protect and defend the rights or property of, Hotmail; or, – act under exigent circumstances to protect the, personal safety of its users or the public., 5 Can Hotmail protect its users from e-mail viruses?, MSN Hotmail is pleased to offer users McAfee VirusScan, for free. Whenever you receive attachments in your, Hotmail account, it will automatically scan them with, McAfee’s popular VirusScan before downloading., MSN Hotmail recently added the ability to have all, attachments you want to send scanned before they can, be attached to your outgoing e-mail. So before you, upload file to send to another user, it will also be scanned, for viruses before you send it, reducing the spread of, viruses to Hotmail users and the other recipients of your, e-mail., Remember, to ensure safety, Hotmail recommends that, you never open attachments from unknown sources., , You can also accent your messages by using Rich Text, Formatting. The Rich Text Formatting option, also allows, you to add emoticons to your e-mail. This new feature, allows you to add selected symbols or emoticons to your, message. These icons help you convey emotion or add, flair within a message., 7 What does it mean when my account is marked, “inactive”?, Currently, if you do not sign in to your Hotmail account for, 60 days, or if you do not sign-in within the first 10 days,, your account will be marked “inactive.” Stored e-mail and, addresses will be deleted, and inbound mail will be, refused. Your Passport will still function, and your Hotmail, e-mail name will be reserved. To re-activate your account,, simply go to http://www.hotmail.com and enter your, Sign-In name and password. You will then be able to, once again send and receive e-mail using hotmail. If your, account stays “inactive” for over a period of 90 days, it, may be permanently deleted., 8 Can I send and receive attachments on Hotmail?, Yes, you can send and receive as many files as you want, to a message - up to 1MB (1024K) of attachments., Attachments sent to your Hotmail account can be, downloaded to your personal computer by clicking them., GIF and JPEG images and HTML files are automatically, displayed in the browser window., , 6 How do I send images and use e-mail stationery to, make e-mail I send more colorful and fun?, (Emoticons/Stationery/RTF), MSN Hotmail offers users stationery to send fun, colorful, messages to family and friends! Always capture the right, mood for your messages by selecting one of the many, different stationery templates. Use the Stationery Chooser, button on the Compose page to view the available, stationery choices., , 208, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.78, , Chatting, video chatting and using social network sites, Objectives : At the end of this lesson you shall be able to, • explain chating process, • explain video chating process, • explain social network services., Chatting Process, A web chat is a system that allows users to communicate, in real time using easily accessible web interfaces. It is, a type of internet online chat distinguished by its simplicity, and accessibility to users who do not wish to take the, time to install and learn to use specialized chat software., This trait allows users instantaneous access and only a, web browser is required to chat. Users will always get, the latest version of a chat service because no software, installation or updates are required., Video Chat, In video chat video of both caller and receiver can be, seen on screen of both user along with audio. So it gives, an impression of face to face interaction though the caller, and receiver can be thousands of mile apart., Social Networking services, A social networking service is a platform to build social, networks or social relations among people who, share, interests, activities, backgrounds or real-life connections., A social network service consists of a representation of, each user (often a profile), his social links, and a variety, of additional services. Social networking is web-based, services that allow individuals to create a public profile,, to create a list of users with whom to share connection,, and view and cross the connections within the system., Most social network services are web-based and provide, means for users to interact over the Internet, such as email and instant messaging.Social network sites are, varied and they incorporate new information and, communication tools such as, mobile connectivity, photo/, video/sharing and blogging. Online community services, , are sometimes considered as a social network service,, though in a broader sense, social network service usually, means an individual-centered service whereas online, community services are group-centered. Social, networking sites allow users to share ideas, pictures,, posts, activities, events, interests with people in their, network., The main types of social networking services are those, that contain category places (such as former school year, or classmates), means to connect with friends (usually, with self-description pages), and a recommendation, system linked to trust. Popular methods now combine, many of these, with American-based services such as, Facebook, Google+,YouTube, LinkedIn, Instagram,, Pinterest, Tumblr and Twitter widely used worldwide;, Nexopia in Canada; Badoo, Bebo, Vkontakte (Russia),, Delphi (also called Delphi Forums), Draugiem.lv (mostly, in Latvia), Hi5 (Europe), Hyves (mostly in The, Netherlands), iWiW (mostly in Hungary), Nasza-Klasa,, Soup (mostly in Poland), Glocals in Switzerland,Skyrock,, The Sphere, StudiVZ (mostly in Germany), Tagged,, Tuenti (mostly in Spain), and XING in parts of Europe;, Hi5 and Orkut in South America and Central America;, Mxit in Africa; and Cyworld, Mixi, Orkut, renren, weibo, and Wretch in Asia and the Pacific Islands., There have been attempts to standardize these services, to avoid the need to duplicate entries of friends and, interests (see the FOAF standard and the Open Source, Initiative). According to experts, the largest social, networking users are Asian-Pacific regions with 615,9, million people. A 2013 survey found that 73% U.S adults, use social networking sites., , Copyright @ NIMI Not to be Republished, , 209
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.79, , Explaining threats to computers connected to Internet & process of protecting computers from it., Objectives : At the end of this lesson you shall be able to, • explain threats to computers connected to Internet, • process of Protecting computers from Internet., A web threat is any threat that uses the World Wide Web, to facilitate cybercrime. Web threats use multiple types, of malware and fraud, all of which utilize HTTP or HTTPS, protocols, but may also employ other protocols and components, such as links in email or IM, or malware attachments or on servers that access the Web. They benefit, cybercriminals by stealing information for subsequent, sale and help absorb infected PCs into botnets., Web threats pose a broad range of risks, including financial damages, identity theft, loss of confidential information/data, theft of network resources, damaged, brand/personal reputation, and erosion of consumer confidence in e-commerce and online banking., It is a type of threat related to information technology, (IT). The IT risk, i.e. risk affecting has gained and increasing impact on society due to the spread of IT processes., Web threats can be divided into two primary categories,, based on delivery method - push and pull. Push-based, threats use spam, phishing, or other fraudulent means, to lure a user to a malicious (often spoofed) website which, then collects information and/or injects malware. Push, attacks use phishing, DNS poisoning (or pharming), and, other means to appear to originate from a trusted source., Precisely-targeted push-based web threats are often referred to as spear phishing to reflect the focus of their, data gathering attack. Spear phishing typically targets, specific individuals and groups for financial gain. In other, push-based web threats, malware authors use social engineering such as enticing subject lines that reference, holidays, popular personalities, sports, pornography,, world events and other hot topics to persuade recipients, to open the email and follow links to malicious websites, or open attachments with malware that accesses the, Web., Pull-based web threats are often referred to as "driveby" threats by experts (and more commonly as "driveby downloads" by journalists and the general public),, since they can affect any website visitor. Cybercriminals, infect legitimate websites, which unknowingly transmit, malware to visitors or alter search results to take users, to malicious websites. Upon loading the page, the user's, browser passively runs a malware downloader in a hidden HTML frame (IFRAME) without any user interaction., , 210, , Internet security, Internet security is a tree branch of computer security, specifically related to the Internet, often involving browser, security but also network security on a more general level, as it applies to other applications or operating systems, on a whole. Its objective is to establish rules and measures to use against attacks over the Internet. The, Internet represents an insecure channel for exchanging, information leading to a high risk of intrusion or fraud,, such as phishing. Different methods have been used to, protect the transfer of data, including encryption., Types of security, Network layer security, TCP/IP which stands for Transmission Control Protocol, (TCP) and Internet Protocol (IP) aka Internet protocol, suite can be made secure with the help of cryptographic, methods and protocols. These protocols include Secure, Sockets Layer (SSL), succeeded by Transport Layer, Security (TLS) for web traffic, Pretty Good Privacy (PGP), for email, and IPsec for the network layer security., Internet Protocol Security (IPsec), This protocol is designed to protect communication in a, secure manner using TCP/IP aka Internet protocol suite., It is a set of security extensions developed by the Internet, Task force IETF, and it provides security and authentication at the IP layer by transforming data using encryption. Two main types of transformation that form the basis, of IPsec: the Authentication Header (AH) and ESP. These, two protocols provide data integrity, data origin authentication, and anti-replay service. These protocols can be, used alone or in combination to provide the desired set, of security services for the Internet Protocol (IP) layer., The basic components of the IPsec security architecture are described in terms of the following functionalities:, •, , Security protocols for AH and ESP, , •, , Security association for policy management and traffic processing, , •, , Manual and automatic key management for the, internet key exchange (IKE), , •, , Algorithms for authentication and encryption, , Copyright @ NIMI Not to be Republished
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The set of security services provided at the IP layer, includes access control, data origin integrity, protection, against replays, and confidentiality. The algorithm allows, these sets to work independently without affecting other, parts of the implementation. The IPsec implementation, is operated in a host or security gateway environment, giving protection to IP traffic., Security token, Some online sites offer customers the ability to use a, six-digit code which randomly changes every 30-60, seconds on a security token. The keys on the security, token have built in mathematical computations and, manipulate numbers based on the current time built into, the device. This means that every thirty seconds there, is only a certain array of numbers possible which would, be correct to validate access to the online account. The, website that the user is logging into would be made aware, of that devices' serial number and would know the, computation and correct time built into the device to verify, that the number given is indeed one of the handful of, six-digit numbers that works in that given 30-60 second, cycle. After 30-60 seconds the device will present a new, random six-digit number which can log into the website., Electronic mail security (E-mail), Background, Email messages are composed, delivered, and stored, in a multiple step process, which starts with the message's, composition. When the user finishes composing the, message and sends it, the message is transformed into, a standard format: an RFC 2822 formatted message., Afterwards, the message can be transmitted. Using a, network connection, the mail client, referred to as a mail, user agent (MUA), connects to a mail transfer agent, (MTA) operating on the mail server. The mail client then, provides the sender's identity to the server. Next, using, the mail server commands, the client sends the recipient, list to the mail server. The client then supplies the, message. Once the mail server receives and processes, the message, several events occur: recipient server, identification, connection establishment, and message, transmission. Using Domain Name System (DNS), services, the sender's mail server determines the mail, server(s) for the recipient(s). Then, the server opens up, a connection(s) to the recipient mail server(s) and sends, the message employing a process similar to that used, by the originating client, delivering the message to the, recipient(s)., Pretty Good Privacy (PGP), Pretty Good Privacy provides confidentiality by, encrypting messages to be transmitted or data files to, be stored using an encryption algorithm such Triple DES, or CAST-128. Email messages can be protected by using, cryptography in various ways, such as the following:, •, , Signing an email message to ensure its integrity and, confirm the identity of its sender., , •, , Encrypting the body of an email message to ensure, its confidentiality., , •, , Encrypting the communications between mail servers, to protect the confidentiality of both message body, and message header., , The first two methods, message signing and message, body encryption, are often used together; however,, encrypting the transmissions between mail servers is, typically used only when two organizations want to protect, emails regularly sent between each other. For example,, the organizations could establish a virtual private network, (VPN) to encrypt the communications between their mail, servers over the Internet. Unlike methods that can only, encrypt a message body, a VPN can encrypt entire, messages, including email header information such as, senders, recipients, and subjects. In some cases,, organizations may need to protect header information., However, a VPN solution alone cannot provide a, message signing mechanism, nor can it provide, protection for email messages along the entire route from, sender to recipient., Multipurpose Internet Mail Extensions (MIME), MIME transforms non-ASCII data at the sender's site to, Network Virtual Terminal (NVT) ASCII data and delivers, it to client's Simple Mail Transfer Protocol (SMTP) to be, sent through the Internet. The server SMTP at the, receiver's side receives the NVT ASCII data and delivers, it to MIME to be transformed back to the original nonASCII data., Message Authentication Code, A Message authentication code (MAC) is a cryptography, method that uses a secret key to encrypt a message., This method outputs a MAC value that can be decrypted, by the receiver, using the same secret key used by the, sender. The Message Authentication Code protects both, a message's data integrity as well as its authenticity., Firewalls, A firewall (computing) controls access between networks., It generally consists of gateways and filters which vary, from one firewall to another. Firewalls also screen, network traffic and are able to block traffic that is, dangerous. Firewalls act as the intermediate server, between SMTP and Hypertext Transfer Protocol (HTTP), connections., Role of firewalls in web security, Firewalls impose restrictions on incoming and outgoing, Network packets to and from private networks. Incoming, or outgoing traffic must pass through the firewall; only, authorized traffic is allowed to pass through it. Firewalls, create checkpoints between an internal private network, and the public Internet, also known as choke, points(borrowed from the identical military term of a, combat limiting geographical feature). Firewalls can, create choke points based on IP source and TCP port, number. They can also serve as the platform for IPsec., Using tunnel mode capability, firewall can be used to, implement VPNs. Firewalls can also limit network, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.04, , Copyright @ NIMI Not to be Republished, , 211
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exposure by hiding the internal network system and, information from the public Internet. Also, WE HAVE A, LOT OF BIG WAYE to deal with it., Types of firewalls, Packet filter, , Ransomware and Scareware, Botnet, A botnet is a network of zombie computers that have, been taken over by a robot or bot that performs largescale malicious acts for the creator of the botnet., , A packet filter is a first generation firewall that processes, network traffic on a packet-by-packet basis. Its main job, is to filter traffic from a remote IP host, so a router is, needed to connect the internal network to the Internet., The router is known as a screening router, which screens, packets leaving and entering the network., , Spyware, , Stateful packet inspection, , A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to, make a computer resource unavailable to its intended, users. Although the means to carry out, motives for, and, targets of a DoS attack may vary, it generally consists of, the concerted efforts to prevent an Internet site or service from functioning efficiently or at all, temporarily or, indefinitely., , In a stateful firewall the circuit-level gateway is a proxy, server that operates at the network level of an Open, Systems Interconnection (OSI) model and statically defines what traffic will be allowed. Circuit proxies will forward Network packets (formatted unit of data ) containing a given port number, if the port is permitted by the, algorithm. The main advantage of a proxy server is its, ability to provide Network Address Translation (NAT),, which can hide the user's IP address from the Internet,, effectively protecting all internal information from the, Internet., Application-level gateway, An application-level firewall is a third generation firewall, where a proxy server operates at the very top of the OSI, model, the IP suite application level. A network packet is, forwarded only if a connection is established using a, known protocol. Application-level gateways are notable, for analyzing entire messages rather than individual, packets of data when the data are being sent or received., Malicious software, Malware, A computer user can be tricked or forced into downloading software onto a computer that is of malicious intent., Such programs are known as malware and come in many, forms, such as viruses, Trojan horses, spyware, and, worms. Malicious software is sometimes used to form, botnets., Viruses, Computer Viruses are programs that can replicate their, structures or effects by infecting other files or structures, on a computer. The common use of a virus is to take, over a computer to steal data., Worms, Computer worms are programs that can replicate themselves throughout a computer network, performing malicious tasks throughout., Trojan horse, A Trojan horse commonly known as a Trojan is a general term for malicious software that pretends to be harmless, so that a user willingly allows it to be downloaded, onto the computer., 212, , The term spyware refers to programs that surreptitiously, monitor activity on a computer system and report that, information to others without the user's consent., Denial-of-service attack, , Browser choice, Web browser statistics tend to affect the amount a Web, browser is exploited. For example, Internet Explorer 6,, which used to own a majority of the Web browser market share, is considered extremely insecure because vulnerabilities were exploited due to its former popularity., Since browser choice is more evenly distributed (Internet, Explorer at 28.5%,Firefox at 18.4%, Google Chrome at, 40.8%, and so on) and vulnerabilities are exploited in, many different browsers., Application vulnerabilities, Applications used to access Internet resources may contain security vulnerabilities such as memory safety bugs, or flawed authentication checks. The most severe of, these bugs can give network attackers full control over, the computer. Most security applications and suites are, incapable of adequate defense against these kinds of, attacks., Internet security products, Antivirus, Antivirus programs and Internet security programs can, protect a programmable device from malware by detecting and eliminating viruses; Before 2000 a user would, pay for antivirus software, 10 years later however, computer users can choose from a host of free security applications on the Internet., Security Suites, So called "security suites" were first offered for sale in, 2003 (McAffee) and contain a suite of firewalls, anti-virus, anti-spyware and more.They may now offer theft, protection, portable storage device safety check, private, internet browsing, cloud anti-spam, a file shredder or, make security-related decisions (answering popup windows) and several were free of charge as of at least, 2012., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.79, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.80 & 1.11.81, , Outlook Express & Google+, Objectives : At the end of this lesson you shall be able to, • explain outlook express, • explain Google+, Microsoft Outlook, , Creation, , Microsoft Outlook is a personal information manager from, Microsoft, available as a part of the Microsoft, Officesuite.Although often used mainly as an email, application, it also includes a calendar, task manager,, contact manager,note taking, journal, and web browsing.It, can be used as a stand-alone application, or can work, with Microsoft Exchange Server and Microsoft, SharePoint Server for multiple users in an organization,, such as shared mailboxes and calendars, Exchange, public folders, SharePoint lists, and meeting schedules., There are third-party add-on applications that integrate, Outlook with devices such as BlackBerry mobile phones, and with other software such as Office and Skypeinternet, communication. Developers can also create their own, custom software that works with Outlook and Office, components using Microsoft Visual Studio. In addition,, Windows Mobile devices can synchronize almost all, Outlook data to Outlook Mobile., , Google launched the Google+ service as an invitationonly "field test" on June 28, 2011, but soon suspended, early invites due to an "insane demand" for new accounts., On August 6, each Google+ member had 150 invitations to give outuntil September 20, 2011, when Google+, opened to everyone 18 years of age or older without the, need for an invitation. It was opened for a younger age, group (13 years or older in US and most countries, 14 or, older in South Korea and Spain, 16 or older in the Netherlands) on January 26, 2012. Google+ is available as a, website and on mobile devices., , Google+, Google+ (pronounced and sometimes written as Google, Plus) is a social networking and identity service that is, owned and operated by Google Inc. Google has described Google+ as a "social layer" that enhances many, of its online properties, and that it is not simply a social, networking website, but also an authorship tool that associates web-content directly with its owner/author. It is, the second-largest social networking site in the world, after Facebook. 540 million monthly active users are, part of the Identity service site, by interacting socially with, Google+'s enhanced properties, like Gmail, +1 button, and, YouTube comments. In October 2013, Google counted, 540 million active users who used at least one Google+, service, of which 300 million users are active in "the, stream"., , Before the launch, Google referred to Google+ as Google, Circles, a name alluding to its emphasis on organising, friendship information. Google+ is considered the, company's fourth foray into social networking, following, Google Buzz (launched 2010, retired in 2011), Google, Friend Connect (launched 2008, retired by March 1,, 2012) and Orkut (launched in 2004, as of 2013 operated, entirely by subsidiary Google Brazil). Sources such as, The New York Times have declared it Google's biggest, attempt to rival the social network Facebook, which has, over 1 billion users., , Copyright @ NIMI Not to be Republished, , 213
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IT & ITES, Related Theory for Exercise 1.12.82 to 1.12.92, COPA - Designing Static WebPages, Web designing, Objectives : At the end of this lesson you shall be able to, • explain web sites and web pages, • explain static and dynamic web pages, • explain HTML, DHTML and XML, • explain the concept of web hosting, web server, application server and database server., Introduction, The World Wide Web (WWW) was created in 1990 by, CERN physicist Tim Berners-Lee. On 30 April 1993,, CERN announced that the World Wide Web would be, free to use for anyone. Before the introduction of HTML, and HTTP, other protocols such as File Transfer Protocol, and the Gopher Protocol were used to retrieve individual, files from a server. These protocols offer a simple directory, structure which the user navigates and chooses files to, download. Documents were most often presented as plain, text files without formatting, or were encoded in word, processors formats., Websites, A website, also written as Web site, web site, or simply, site, is a set of related web page containing content, (media) such as written language, Image, video, sound,, etc. A website is hosted on at least one web server,, accessible via a network such as the internet or a private, local area network through an Internet address known, as a uniform resource locator. All publicly accessible, websites collectively constitute the world wide web., A webpage is a document, typically written in plain text, interspersed with formatting instructions of Hypertext, Mark-up Language (HTML) XHTML. A webpage may, incorporate elements from other websites with suitable, HTML anchor., Web pages are accessed and transported with the, Hypertext Transfer Protocol (HTTP), which may optionally, employ encryption secure, HTTPS to provide security and, privacy for the user of the webpage content. The user's, application, often a web browser, renders the page content, according to its HTML Mark-up instructions onto a, Computer monitor., The pages of a website can usually be accessed from a, simple Uniform Resource Locator (URL) called the web, address. The URLs of the pages organize them into a, hierarchy, although hyperlink between them conveys the, reader's perceived sitemap and guides the reader's, navigation of the site which generally includes a Home, page with most of the links to the site's web content, and, a supplementary about page, contact page and link page., , 214, , Some websites require a subscription to access some or, all of their content. Examples of subscription websites, include many business sites, parts of news websites,, Academic journal websites, gaming websites, file-sharing, websites, Internet forum, web-based Email, Social, networking websites, websites providing real-time Stock, market data, and websites providing various other, services (e.g., websites offering storing and/or sharing, of images, files and so forth)., A website may be, •, , Personal website, , •, , Commercial website, , •, , E-Government, , •, , Non-profit organization website., , Static Website, A static website is one that has web pages stored on the, server in the format that is sent to a client web browser. It, is primarily coded in Hypertext Markup Language (HTML)., Simple forms or marketing examples of websites, such, as classic website, a five-page website or a brochure, website are often static websites, because they present, pre-defined, static information to the user. This may, include information about a company and its products, and services through text, photos, animations, audio/video, and interactive menus and navigation., This type of website usually displays the same information, to all visitors. Similar to handing out a printed brochure to, customers or clients, a static website will generally provide, consistent, standard information for an extended period of, time. Although the website owner may make updates, periodically, it is a manual process to edit the text, photos, and other content and may require basic website design, skills and software., Advantages, •, , Static Websites are easier to develop, , •, , Can be developed quickly, , •, , They are indexed easily by search engines as all the, web pages actually exist on the server, which is not, the case with dynamic websites., , Copyright @ NIMI Not to be Republished
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Disadvantages, , •, , Content Site: these sites create and sell of original, content to end-user. (e.g., Slate, About.com)., , •, , Static websites cannot do complex tasks required by, many online services., , •, , •, , Updating a whole site can be cumbersome and time, consuming., , Corporate website: used to provide information regarding, business, organization, or service., , •, , •, , An isolation of Data and Design is not provided in static, websites., , Commerce site (or eCommerce site): these sites are, designed for purchasing or selling goods, such as, Amazon.com, CSN Stores, and Overstock.com., , •, , Community site: sites where persons with similar, interests communicate to each other through chatting, and messaging or through soci message boards, such, as MySpace or Facebook., , •, , City Site: A site that shows information about a certain, city or town and events that takes place in that town., Usually created by the city council. For example,, Richmond.com is the geodomain for Richmond,, Virginia., , •, , Information site: contains content that is intended to, inform visitors, but not necessarily for commercial, purposes, such as: RateMyProfessors.com, Free, Internet Lexicon and Encyclopaedia. Most, government, educational and non-profit institutions, have an informational site., , •, , Mirror site: A complete reproduction of a website., , •, , News site: similar to an information site, but dedicated, to dispensing news and commentary., , •, , Personal homepage: run by an individual or a small, group such as a family that contains information or, any content that the individual wishes to include. These, are usually uploaded using a web hosting service such, as Geocities., , •, , Phish Site: a website created to fraudulently acquire, sensitive information, such as passwords and credit, card details, by disguising as a trustworthy person or, business (such as Social Security Administration,, PayPal) in an electronic communication., , •, , Political site: A site on which people may voice political, views., , •, , Rating site: A site on which people can praise or, disparage what is featured., , •, , Review site: A site on which people can post reviews, for products or services., , •, , School site: a site on which teachers, students, or, administrators can post information about current, events at or involving their school., , •, , Video sharing: A site that enables user to upload, videos, such as YouTube and Google Video., , •, , Search engine site: a site that provides general, information and is intended as a gateway for retrieving, other sites. Google, Yahoo and MSN are the most, widely known search engines., , •, , Shock site: includes images or other material that is, intended to be offensive to most viewers (e.g., rotten.com)., , Dynamic Website, A dynamic website is one that changes or customizes, itself frequently and automatically, based on certain, criteria., Dynamic websites can have two types of dynamic activity:, Code and Content. Dynamic code is invisible or behind, the scenes and dynamic content is visible or fully displayed, Advantages, •, , Can do more complex task required by online services., , •, , They are easier to update., , •, , Isolation of data and design allows programmers and, content writers to work independently., , Disadvantages, •, , Can take more time to build., , •, , Can be difficult to build., , •, , Dynamic websites are not indexed by search engines, easily, since they do not have actual web pages, present on the web server. With continuous, improvements in search engine technology, this, problem is now very much eliminated and you can, find that many dynamic websites are very well indexed, by search engines now a days., , A few such classifications are:, •, , •, , •, , Affiliate: enabled portal that renders not only its custom, CMS but also syndicated content from other content, providers for an agreed fee. There are usually three, relationship tiers. Affiliate Agencies (e.g., Commission, Junction), Advertisers (e.g., eBay) and consumer (e.g.,, Yahoo!)., Archive site: used to preserve valuable electronic, contents that are on verge of extinction. For examples:, Internet Archive, which since 1996 has preserved, billions of old and new web pages; and Google Groups,, which in early 2005 had preserved over 845,000,000, messages posted to Usenet news/discussion groups., Blog Site: sites generally used to post online diaries,, comments or views that may include discussion, forums (e.g., blogger, Xanga)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 215
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•, , Warez: a site designed to host and let users download, copyrighted materials illegally., , •, , Web portal: a site is vehicle that provides a gateway to, other resources on the Internet or an intranet., , Web Pages, A web page or webpage is a Document or information, resource that is suitable for the world wide Web and can, be accessed through a web browser and displayed on a, computer display or mobile device. This information is, usually in HTML or XHTML format, and may provide, navigation bar to other web pages via Hyper text Hyper, link. Web pages frequently subsume other resources such, as Cascading Style Sheet, Client-side-scripting and, Images into their final presentation., Web pages may be retrieved from a local computer or, from a remote Web server. The web server may restrict, access only to a private network, e.g. a corporate Intranet, or it may publish pages on the World Wide Web. Web, pages are requested and served from web. Web server, using Hypertext Transfer Protocol (HTTP)., Web pages may consist of files of static text and other, Web content stored within the Web server 's file, system(Static Web page), or may be constructed by, Server-side scripting when they are requested (Dynamic, web page). Client-side scripting can make web pages more, responsive to user input once on the client browser., , Web Browser, A Web browser can have a Graphical User Interface, like, Internet Explorer, Mozilla Firefox, Google Chrome and, Opera (web browser), or can be Command Line Interface,, like Lynx (web browser) (Fig 1) or Links (web browser)., Web users with disabilities often use assistive, technologies and adaptive strategies to Web accessibility, web pages. Users may be colour blind, may or may not, want to use a mouse perhaps due to repetitive stress, injury or motor-neurone problems, may be deaf and, require audio to be captioned, may be blind and using a, Screen reader or display, may need screen magnification,, etc. Disabled and able-bodied users may disable the, download and viewing of images and other media, to, save time, network bandwidth or merely to simplify their, browsing experience., Users of mobile devices often have restricted displays and, bandwidth. Anyone may prefer not to use the fonts, font, sizes, styles and colour schemes selected by the web, page designer and may apply their own CSS styling to, the page. The World Wide Web Consortium (W3C) and, Web Accessibility Initiative (WAI) recommend that all web, pages should be designed with all of these options in mind., , Fig 1, , 216, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Downloading a Software from Internet, 1 Create a Temporary Files folder by opening My, Computer, double click on your hard drive (typically, the C: drive), then select File/New/Folder as on Fig 2., Fig 2, , 2 Type "Temporary File" and name it as on Fig 3., , Fig 3, , 3 Type "My SQL 5. 1 free download " from freeware, software website on internet., Note: As an example Choose "http://, dev.mysql.com/downloads/" select "My SQL, Community server" in download from the, opened site as on Fig 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 217
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Fig 4, , My Sql Community, , 4 Click "MySQL Community Server 5.1 " from looking for previous version option as on Fig 5, Fig 5, , 5 Choose "Windows (x86, 32-bit), MSI Installer Essentials - Recommended" and click download (Fig.6)., , 218, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 6, , Note: Save the "My SQL 5.1.63" in the created, Folder name " Temporary Folder", , documents (hypertext) and make web documents, interactive (such as with forms)., , 6 Burn the Downloaded "My SQL 5.1.63" in a CD ROM, for Installation., , HTML is a defined standard markup language. That, standard was developed by the World Wide Web, Consortium (W3C). It is based upon SGML (Standard, Generalized Markup Language). It is a language that uses, tags to define the structure of your text. Elements and, tags are defined by the < and > characters., , WEB LANGUAGES, Web languages are called as Markup languages are, designed for the processing, definition and presentation, of text. The language specifies code for formatting, both, the layout and style, within a text file. The code used to, specify the formatting are called tags, Four Types of Markup languages, 1 BML, , DHTML, Dynamic HTML is not really a new specification of HTML,, but rather a new way of looking at and controlling the, standard HTML codes and commands., When thinking of dynamic HTML, we need to remember, the qualities of standard HTML, especially that once a, page is loaded from the server, it will not change until, another request comes to the server. Dynamic HTML give, more control over the HTML elements and allows them, to change at any time, without returning to the Web server., , 2 HTML, 3 DHTML, 4 XML, BML (Better markup language), BML is essentially a simple macro language. Macros are, called blocks in BML. Blocks are defined in look files, and, are invoked in BML files. Blocks accept parameters and, are divided into several types, according to how parameters, are transmitted and how the definition of the block is able, to make use of them., HTML (Hyper text markup Language), HTML or HyperText Markup Language is the language of, the web. All web pages are written in HTML. HTML defines, the way that images, multimedia, and text are displayed, in web browsers. It includes elements to connect the, , There are four parts to DHTML:, •, •, •, •, , Document Object Model (DOM) (definition), Scripts, Cascading Style Sheets (CSS), XHTML, , DOM, The DOM is allows to access any part of Web page to, change it with DHTML. Every part of a Web page is, specified by the DOM and using its consistent naming, conventions can access them and change their properties., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 219
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Scripts, , Data binding, , Scripts written in either JavaScript or ActiveX are the two, most common scripting languages used to activate, DHTML. You use a scripting language to control the, objects specified in the DOM., , This is an IE only feature. Microsoft developed this to allow, easier access to databases from Web sites. It is very, similar to using a CGI to access a database, but uses an, ActiveX control to function., , Cascading Style Sheets, , XML, , CSS is used in DHTML to control the look and feel of the, Web page. Style sheets define the colors and fonts of, text, the background colors and images, and the, placement of objects on the page. Using scripting and, the DOM, we can change the style of various elements., , Extensible Markup Language (XML) is a markup language, that defines a set of rules for encoding documents in a, format that is bothhuman-readable and machine-readable., It is defined in the XML 1.0 Specification produced by the, W3C, and several other related specifications, all gratis, open standards. The design goals of XML emphasize, simplicity, generality, and usability over the Internet. It is a, textual data format with strong support via Unicode for the, languages of the world. Although the design of XML focuses, on documents, it is widely used for the representation of, arbitrary data structures, for example in web services, , XHTML, XHTML or HTML 4.x is used to create the page itself and, build the elements for the CSS and the DOM to work on., There is nothing special about XHTML for DHTML - but, having valid XHTML is even more important, as there, are more things working from it than just the browser., Features of DHTML, , Creating an HTML document, , There are four primary features of DHTML:, , Before start writing code to write a web page, it is a good, practice to plan ahead the appearance of the web page., An HTML document has two elements:, , 1 Changing the tags and properties, , 1 Document Content, , 2 Real-time positioning, , 2 Tags, , 3 Dynamic fonts (Netscape Communicator), 4 Data binding (Internet Explorer), Changing the tags and properties, This is one of the most common uses of DHTML. It allows, to change the qualities of an HTML tag depending on an, event outside of the browser (such as a mouse click, time,, or date, and so on). we can use this to preload information, onto a page, and not display it unless the reader clicks, on a specific link., Real-time postioning, Objects, images, and text moving around the Web page., This can allow we to play interactive games with the, readers or animate portions of the screen., Dynamic Fonts, This is a Netscape only feature. Netscape developed this, to get around the problem designers had with not knowing, what fonts would be on a reader's system. With dynamic, fonts, the fonts are encoded and downloaded with the page,, so that the page always looks how the designer intended, it to., , 220, , Document content is the information on a web page, that the user will see. That information could be text or, graphics., Tags are the HTML codes that control how the document, content will appear. The tags, in other words, will, determine whether the text will be bold, black or blue, or, of font type Time New Roman or Airal., Start Notepad, To start Notepad go to:, Start, All Programs, Accessories, Notepad, Edit Your HTML with Notepad (Fig 7), Type your HTML code into your Notepad:, Save Your HTML, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 7, , Select Save as.. in Notepad's file menu., When you save an HTML file, you can use either the .htm, or the .html file extension., Save the file in a folder that is easy to remember, , Start your web browser and open your html file from the, File, Open menu, or just browse the folder and doubleclick your HTML file., The result should look much like this: (Fig 8), , Run the HTML in Your Browser, Fig 8, , Structure of Markup Language, An HTML document has two* main parts:, 1 head. The head element contains title and meta data, of a web document., 2 body. The body element contains the information that, you want to display on a web page., , To make your web pages compatible with HTML 4, you, need to add a document type declaration (DTD) before the, HTML element. Many web authoring software add DTD, and basic tags automatically when you create a new web, page., In a web page, the first tag (specifically, <html>) indicates, the markup language that is being used for the document., The <head> tag contains information about the web page., Lastly, the content appears in the <body> tag. (Fig 9), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 221
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Fig 9, , The <!DOCTYPE> Declaration, There are many different documents on the web. A browser, can only display a document correctly, if it knows what, kind of document it is., There are also many different versions of HTML, and a, browser can only display an HTML page 100% correctly, if it knows the exact HTML version used in the page. This, is what <!DOCTYPE> is used for., , •, , Provides a title for the page when it is added to, favorites., , •, , Displays a title for the page in search-engine results., , HTML Element Syntax, •, , An HTML element starts with a start tag / opening tag, , •, , An HTML element ends with an end tag / closing tag, , •, , <!DOCTYPE> is not an HTML tag. It is an information (a, declaration) to the browser about what version the HTML, is written in., , The element content is everything between the start, and the end tag, , •, , Some HTML elements have empty content, , •, , Empty elements are closed in the start tag, , The HTML <head> Element, , •, , Most HTML elements can have attributes, , The <head> element is a container for all the head, elements. Elements inside <head> can include scripts,, instruct the browser where to find style sheets, provide, meta information, and more., The following tags can be added to the head section: <title>,, <base>, <link>, <meta>, <script>, and <style>., , HTML Headings, HTML headings are defined with the <h1> to <h6> tags., Examples, <html>, <body>, <h1>This is heading 1</h1>, , The HTML <title> Element, The <title> tag defines the title of the document., , <h2>This is heading 2</h2>, <h3>This is heading 3</h3>, , The title element is required in all HTML/XHTML, documents., , <h4>This is heading 4</h4>, , The title element:, , <h6>This is heading 6</h6>, , •, , Defines a title in the browser toolbar., , 222, , <h5>This is heading 5</h5>, </body>, </html>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 742 : Result, , Fig 10, , This is heading 1, This is heading 2, This is heading 3, This is heading 4, This is heading 5, This is heading 6, HTML Paragraphs, HTML paragraphs are defined with the <p> tag., , HTML Attributes, , <html>, , •, , HTML elements can have attributes, , <body>, , •, , Attributes provide additional information about an, element, , <p>This is a paragraph.</p>, , •, , Attributes are always specified in the start tag, , <p>This is a paragraph.</p>, , •, , Attributes come in name/value pairs like:, name="value", , <p>This is a paragraph.</p>, , </body>, </html>, , Attribute Example, , Examples, This is a paragraph., , HTML links are defined with the <a> tag. The link address, is specified in the href attribute:, , This is a paragraph., , <html>, , This is a paragraph., , <body>, , HTML Links, , <a href="http://www.yahoo.com">, , HTML links are defined with the <a> tag., , This is a link</a>, , <html>, , </body>, , <body>, , </html>, , <a href="http://www.facebook.com">, , Result, , This is a link</a>, , This is the link, , </body>, , By clicking the link yahoo home page appears (Fig 11)., , </html>, , Formatting, , Result, , Create Line Breaks - The <br /> Element:, , This is a link, By clicking the link it shows the facebook login page, HTML Images, HTML images are defined with the <img> tag., , Whenever the <br /> element, anything following it starts, on the next line. This tag is an example of an empty, element, where you do not need opening and closing tags,, as there is nothing to go in between them., , <html>, <body>, <img src="w3schools.jpg" width="104" height="142" />, </body>, </html>, Result (Fig 10), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 223
Page 743 : Fig 11, , Example:, , Soft Hyphens:, , Hello<br/>, You come most carefully upon your hour.<br/>, Thanks<br/>, , <p style="text-align: justify;"> The morbid fear of, the number 13, or triskaidekaphobia, has plagued, some important historic figures like Mahamiya and, Nanao.</p>, , Mahnaz, Result, , This will produce following result:, , Hello, You come most carefully upon your hour., Thanks, Mahnaz, , Example for soft hyphen - The morbid fear of the, number 13, or triskaidekaphobia, has plagued some, important historic figures like Mahamiya and Nanao., Preserve Formatting - The <pre> Element:, , To Become, Centring Content - The <center> Element:, You can use <center> tag to put any content in the center, of the page or any table cell., Example:, <p>This is not in the center.</p>, <center>, <p>This is in the center.</p>, </center>, This will produce following result:, This is not in the center., This is in the center., , 224, , Occasionally, you will want to allow a browser to hyphenate, long words to better justify a paragraph. For example,, consider the following code and its resulting output., , Sometimes you want your text to follow the exact format, of how it is written in the HTML document. In those cases,, you can use the preformatted tag (<pre>)., Any text between the opening <pre> tag and the closing, </pre> tag will preserve the formatting of the source, document., <pre>, function testFunction( strText ){, alert (strText), }, </pre>, This will produce following result:, function testFunction( strText ){, alert (strText), }, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 744 : Horizontal Rules - The <hr /> Element, , Underlined Text - The <u> Element:, , Horizontal rules are used to visually break up sections of, a document. The <hr> tag creates a line from the current, position in the document to the right margin and breaks, the line accordingly., , Anything that appears in a <u>...</u> element is displayed, with underline, like the word underlined here:, , For example you may want to give a line between two, paragraphs as follows:, , <p>The following word uses a <u>underlined</, u> typeface.</p>, This will produce following result:, , <p>This is paragraph one and should be on top</p>, , The following word uses a underlined typeface., , <hr />, , Strike Text - The <strike> Element:, , <p>This is paragraph two and should be at bottom</, p>, This will produce following result:, This is paragraph one and should be on top, This is paragraph two and should be at bottom, Again <hr /> tag is an example of an empty element,, where you do not need opening and closing tags, as there, is nothing to go in between them., Note: The <hr /> element has a space between, the characters hr and the forward slash. If you, omit this space, older browsers will have, trouble rendering the line break, while if you, miss the forward slash character and just use, <hr> it is not valid XHTML, Presentational Tags:, If you use a word processor, you are familiar with the, ability to make text bold, italicized, or underlined; these, are just three of the ten options available to indicate how, text can appear in HTML and XHTML., Bold Text - The <b> Element:, Anything that appears in a <b>...</b> element is displayed, in bold, like the word bold here:, <p>The following word uses a <b>bold</b>, typeface.</p>, This will produce following result:, The following word uses a bold typeface., Italic Text - The <i> Element:, Anything that appears in a <i>...</i> element is displayed, in italicized, like the word italicized here:, <p>The following word uses a <i>italicized</i>, typeface.</p>, This will produce following result:, The following word uses a italicized typeface., , Anything that appears in a <strike>...</strike> element is, displayed with strikethrough, which is a thin line through, the text:, <p>The, following, word, uses, a, <strike>strikethrough</strike> typeface.</p>, This will produce following result:, The following word uses a strikethrough typeface., Monospaced font - The <tt> Element:, The content of a <tt> element is written in monospaced, font. Most fonts are known as variable-width fonts, because different letters are of different widths (for, example, the letter m is wider than the letter i). In a, monospaced font, however, each letter is the same width., <p>The, following, word, uses, <tt>monospaced</tt> typeface.</p>, , a, , This will produce following result:, The following word uses a monospaced typeface., Superscript Text - The <sup> Element:, The content of a <sup> element is written in superscript;, the font size used is the same size as the characters, surrounding it but is displayed half a character.s height, above the other characters., <p>The, following, word, uses, <sup>superscript</sup> typeface.</p>, , a, , This will produce following result:, The following word uses a superscript typeface., Subscript Text - The <sub> Element:, The content of a <sub> element is written in subscript;, the font size used is the same as the characters surrounding, it, but is displayed half a character.s height beneath the, other characters., <p>The, following, word, uses, <sub>subscript</sub> typeface.</p>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , a, , 225
Page 745 : This will produce following result:, The following word uses a subscript typeface., Larger Text - The <big> Element:, The content of the <big> element is displayed one font, size larger than the rest of the text surrounding it., <p>The following word uses a <big>big</big>, typeface.</p>, , HTML Hyperlinks (Links), A hyperlink (or link) is a word, group of words, or image, that you can click on to jump to a new document or a new, section within the current document., When you move the cursor over a link in a Web page,, the arrow will turn into a little hand., Links are specified in HTML using the <a> tag., , This will produce following result:, , The <a> tag can be used in two ways:, , The following word uses a big typeface., , 1 To create a link to another document, by using the, href attribute, , Smaller Text - The <small> Element:, The content of the <small> element is displayed one font, size smaller than the rest of the text surrounding it., <p>The following word uses a <small>small</, small> typeface.</p>, , 2 To create a bookmark inside a document, by using, the name attribute, The HTML code for a link is simple. It looks like this:, <a href="url">Link text</a>, , This will produce following result:, , The href attribute specifies the destination of a link., , The following word uses a small typeface., , <a href="http://www.yahoo.com/">Visit yahoo</a>, , Styling HTML with CSS, , which will display like this: Visit yahoo.com, , CSS was introduced together with HTML 4, to provide a, better way to style HTML elements., , Clicking on this hyperlink will send the user to Yahoo, homepage., , CSS can be added to HTML in the following ways:, , The "Link text" doesn't have to be text. It can be an image, or any other HTML element., , •, , Inline - using the style attribute in HTML elements, , •, , Internal - using the <style> element in the <head>, section, , •, , External - using an external CSS file, , <html>, <body style="background-color:PowderBlue;">, <h1>Look! Styles and colors</h1>, <p style="font-family:verdana;color:red;">, This text is in Verdana and red</p>, <p style="font-family:times;color:green;">, This text is in Times and green</p>, <p style="font-size:30px;">This text is 30 pixels high</, p>, </body>, , HTML Links - The target Attribute, The target attribute specifies where to open the linked, document., The example below will open the linked document in a, new browser window or a new tab:, Example, <a href="http://www.yahoo.com/" target="_blank">Visit, yahoo !</a>, <html>, <body>, <a href="http://www.yahoo.com" target="_blank">Visit, yahoo.com!</a>, , </html>, , <p>If you set the target attribute to "_blank", the link will, open in a new browser window/tab.</p>, , Result:, , </body>, , Look! Styles and colors, , </html>, , This text is in Verdana and red, This text is in Times and green, This text is 30 pixels high, 226, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 746 : Result, , <img src="boat.gif" alt="Big Boat" />, , Visit yahoo.com!, , The alt attribute provides alternative information for an image, if a user for some reason cannot view it (because of slow, connection, an error in the src attribute, or if the user uses, a screen reader)., , If you set the target attribute to "_blank", the link will open, in a new browser window/tab., HTML Images - The <img> Tag and the Src Attribute, In HTML, images are defined with the <img> tag., The <img> tag is empty, which means that it contains, attributes only, and has no closing tag., To display an image on a page, you need to use the src, attribute. Src stands for "source". The value of the src, attribute is the URL of the image you want to display., Syntax for defining an image:, <img src="url" alt="some_text"/>, The URL points to the location where the image is stored., An image named "bamboo. gif", located in the "images", directory on "www.w3schools.com" has the URL: http://, www.backgroundlabs.com/index.php?search=bamboo., The browser displays the image where the <img> tag, occurs in the document. If you put an image tag between, two paragraphs, the browser shows the first paragraph,, then the image, and then the second paragraph., HTML Images - The Alt Attribute, The required alt attribute specifies an alternate text for an, image, if the image cannot be displayed., The value of the alt attribute is an author-defined text:, , HTML Images - Set Height and Width of an Image, The height and width attributes are used to specify the, height and width of an image., The attribute values are specified in pixels by default:, <img src="rose.jpg" alt="Rose" width="304" height="228", />, Note: It is a good practice to specify both the height and, width attributes for an image. If these attributes are set,, the space required for the image is reserved when the, page is loaded. However, without these attributes, the, browser does not know the size of the image. The effect, will be that the page layout will change during loading, (while the images load)., If an HTML file contains ten images - eleven files are, required to display the page right. Loading images takes, time, so my best advice is: Use images carefully., When a web page is loaded, it is the browser, at that, moment, that actually gets the image from a web server, and inserts it into the page. (Fig 12) Therefore, make sure, that the images actually stay in the same spot in relation, to the web page, otherwise your visitors will get a broken, link icon. The broken link icon is shown if the browser, cannot find the image., , Fig 12, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 227
Page 747 : <html>, , All major browsers display the text in the <th> element as, bold and centered., , <body>, , <table border="1">, , <h2>Friendship Card</h2>, <img border="0" src="/images/Rose.jpg" alt="Rose", width="304" height="228" />, , <tr>, <th>Header 1</th>, , </body>, , <th>Header 2</th>, , </html>, , </tr>, , HTML Tables, , <tr>, , Tables are defined with the <table> tag., , <td>row 1, cell 1</td>, , A table is divided into rows (with the <tr> tag), and each, row is divided into data cells (with the <td> tag). td stands, for "table data," and holds the content of a data cell. A, <td> tag can contain text, links, images, lists, forms, other, tables, etc., , <td>row 1, cell 2</td>, , Table Example, , </tr>, <tr>, <td>row 2, cell 1</td>, <td>row 2, cell 2</td>, , <table border="1">, , </tr>, , <tr>, , </table>, , <td>row 1, cell 1</td>, , How the HTML code above looks in your browser:, , <td>row 1, cell 2</td>, </tr>, <tr>, <td>row 2, cell 1</td>, , Header 1, , Header 2, , row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , <td>row 2, cell 2</td>, , HTML Unordered Lists, , </tr>, , An unordered list starts with the <ul> tag. Each list item, starts with the <li> tag., , </table>, How the HTML code above looks in a browser:, row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , HTML Tables and the Border Attribute, If you do not specify a border attribute, the table will be, displayed without borders. Sometimes this can be useful,, but most of the time, we want the borders to show., , The list items are marked with bullets (typically small black, circles)., <ul>, <li>Coffee</li>, <li>Milk</li>, </ul>, How the HTML code above looks in a browser:, , To display a table with borders, specify the border attribute:, , •, , Coffee, , <table border="1">, , •, , Milk, , <tr>, , HTML Ordered Lists, , <td>Row 1, cell 1</td>, , An ordered list starts with the <ol> tag. Each list item, starts with the <li> tag., , <td>Row 1, cell 2</td>, , The list items are marked with numbers., , </tr>, , <ol>, , </table>, , <li>Coffee</li>, , HTML Table Headers, Header information in a table are defined with the <th>, tag., , <li>Milk</li>, </ol>, How the HTML code above looks in a browser:, 1 Coffee, , 228, , 2 Milk, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 748 : HTML Definition Lists, A definition list is a list of items, with a description of each, item., , When used together with CSS, the <div> element can be, used to set style attributes to large blocks of content., , The <dl> tag is used in conjunction with <dt> (defines the, item in the list) and <dd> (describes the item in the list):, , Another common use of the <div> element, is for document layout. It replaces the "old way" of defining layout, using tables. Using tables is not the correct use of the, <table> element. The purpose of the <table> element is, to display tabular data., , <dl>, , The HTML <span> Element, , <dt>Coffee</dt>, , The HTML <span> element is an inline element that can, be used as a container for text., , The <dl> tag defines a definition list., , <dd>- black hot drink</dd>, <dt>Milk</dt>, <dd>- white cold drink</dd>, </dl>, How the HTML code above looks in a browser:, Coffee - black hot drink, Milk- white cold drink, Note : Inside a list item you can put text, line, breaks, images, links, other lists, etc., , The <span> element has no special meaning., When used together with CSS, the <span> element can, be used to set style attributes to parts of the text., HTML Grouping Tags, Tag, , Description, , <div>, , Defines a div, , <span>, , Defines a span, , HTML Layout, Website Layouts, , HTML List Tags, Tag, , Description, , <ol>, , Defines an ordered list, , <ul>, , Defines an unordered list, , <li>, , Defines a list item, , <dl>, , Defines a definition list, , <dt>, , Defines an item in a definition list, , <dd>, , Defines a description of an item in a, definition list, , HTML elements can be grouped together with <div> and, <span>, , Most websites have put their content in multiple columns, (formatted like a magazine or newspaper)., Multiple columns are created by using <div> or <table>, elements. CSS are used to position elements, or to create backgrounds or colorful look for the pages., HTML Layouts - Using <div> Elements, The div element is a block level element used for grouping, HTML elements., The following example uses five div elements to create a, multiple column layout, creating the same result as in the, previous example:, Example, , HTML Block Elements, , <div>, , Most HTML elements are defined as block level elements, or as inline elements., , <!DOCTYPE html>, , Block level elements normally start (and end) with a new, line when displayed in a browser., , <body>, , Examples: <h1>, <p>, <ul>, <table>, HTML Inline Elements, Inline elements are normally displayed without starting a, new line., Examples: <b>, <td>, <a>, <img>, The HTML <div> Element, The HTML <div> element is a block level element that can, be used as a container for grouping other HTML elements., The <div> element has no special meaning. Except that,, because it is a block level element, the browser will display a line break before and after it., , <html>, <div id="container" style="width:500px">, <div id="header" style="background-color:#FFA500;">, <h1 style="margin-bottom:0;">Main Title of Web Page</, h1></div>, <divid="menu"style="backgroundcolor:#FFD700;height:200px;width:100px;float:left;">, <b>Menu</b><br />, HTML<br />, CSS<br />, JavaScript</div>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 229
Page 749 : <div, id="content", style="backgroundcolor:#EEEEEE;height:200px;width:400px;float:left;">, Content goes here</div>, <div, id="footer", style="backgroundcolor:#FFA500;clear:both;text-align:center;">, , </div>, </div>, </body>, </html>, Result (Fig 13), , Fig 13, , HTML Forms, , First name: <input type="text" name="firstname" /><br />, , HTML forms are used to pass data to a server., , Last name: <input type="text" name="lastname" />, , A form can contain input elements like text fields,, checkboxes, radio-buttons, submit buttons and more. A, form can also contain select lists, textarea, fieldset, legend, and label elements., , </form>, , The <form> tag is used to create an HTML form:, , Last name:, , <form>., , How the HTML code above looks in a browser:, First name:, , Note: The form itself is not visible. Also note, that the default width of a text field is 20, characters., , input elements., </form>, HTML Forms - The Input Element, , Password Field, , The most important form element is the input element., , <input type="password" /> defines a password field:, , The input element is used to select user information., , <form>, , An input element can vary in many ways, depending on, the type attribute. An input element can be of type text, field, checkbox, password, radio button, submit button,, and more., , Password: <input type="password" name="pwd" />, , The most used input types are described below., , Password:, , Text Fields, <input type="text" /> defines a one-line input field that a, user can enter text into:, , </form>, How the HTML code above looks in a browser:, , Note: The characters in a password field are, mased (shown as asterisks or circles), , <form>, , 230, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Radio Buttons, <input type="radio" /> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of, choices:, <form>, , If you type some characters in the text field above, and, click the "Submit" button, the browser will send your input, to a page called "html_form_action.asp". The page will, show you the received input., HTML Iframes, , <input type="radio" name="sex" value="male" /> Male<br/>, <input type="radio" name="sex" value="female" /> Female, </form>, How the HTML code above looks in a browser:, , Syntax for adding an iframe:, <iframe src="URL"></iframe>, The URL points to the location of the separate page., , Male, , Iframe - Set Height and Width, , Female, , The height and width attributes are used to specify the, height and width of the iframe., , Checkboxes, <input type="checkbox" /> defines a checkbox., Checkboxes let a user select ONE or MORE options of a, limited number of choices., <form>, <input type="checkbox" name="vehicle" value="Bike" />, I have a bike<br />, <input type="checkbox" name="vehicle" value="Car" /> I, have a car, , The attribute values are specified in pixels by default, but, they can also be in percent (like "80%")., Example, <!DOCTYPE html>, <html>, <body>, <iframe src="demo_iframe.htm", height="200"></iframe>, , width="200", , </body>, , </form>, How the HTML code above looks in a browser:, , </html>, It will appear as shown in Fig 14., , I have a bike, , Iframe - Remove the Border, , I have a car, , The frameborder attribute specifies whether or not to display, a border around the iframe., , Submit Button, <input type="submit" /> defines a submit button., A submit button is used to send form data to a server. The, data is sent to the page specified in the form's action, attribute. The file defined in the action attribute usually, does something with the received input:, <form name="input" action="html_form_action.asp", method="get">, Username: <input type="text" name="user" />, <input type="submit" value="Submit" />, , Set the attribute value to "0" to remove the border:, Example, <iframe src="demo_iframe.htm" frameborder="0"></, iframe>, Use iframe as a Target for a Link, An iframe can be used as the target frame for a link., The target attribute of a link must refer to the name attribute, of the iframe:, , </form>, How the HTML code above looks in a browser:, Username:, , Submit, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 231
Page 751 : Fig 14, , Example, , HTML Colour, , <iframe src="demo_iframe.htm" name="iframe_a"></, iframe>, < p > < a h r e f = " h t t p : / / w w w. y a h o o . c o m ", target="iframe_a">yahoo.com</a></p>, HTML iframe Tag, , Color Values, HTML colors are defined using a hexadecimal notation, (HEX) for the combination of Red, Green, and Blue color, values (RGB)., The lowest value that can be given to one of the light sources, is 0 (in HEX: 00). The highest value is 255 (in HEX: FF)., , Tag, , Description, , HEX values are specified as 3 pairs of two-digit numbers,, starting with a # sign., , <iframe>, , Defines an inline sub window (frame), , Color Values (Fig 15), , Fig 15, , Color, , Color HEX, , Color RGB, , #000000, , rgb(0,0,0), , #FF0000, , rgb(255,0,0), , #00FF00, , rgb(0,255,0), , #0000FF, , rgb(0,0,255), , #FFFF00, , rgb(255,255,0), , #00FFFF, , rgb(0,255,255), , #FF00FF, , rgb(255,0,255), , #C0C0C0, , rgb(192,192,192), , #FFFFFF, , rgb(255,255,255), , <!DOCTYPE html>, , Color set by using hex value, , <html>, , </p>, , <body>, , <p style="background-color:rgb(255,255,0)">, , <p style="background-color:#FFFF00">, , Color set by using rgb value, , 232, , </p>, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 752 : <p style="background-color:yellow">, Color set by using color name, </p>, </body>, , <noscript>Sorry, your browser does not support, JavaScript!</noscript>, <p>A browser without support for JavaScript will show the, text in the noscript element.</p>, </body>, , </html>, , </html>, , Result, Color set by using hex value, Color set by using rgb value, Color set by using color name, DHTML, The HTML script Element, The <script> tag is used to define a client-side script,, such as a JavaScript., The script element either contains scripting statements, or it points to an external script file through the src attribute., The required type attribute specifies the MIME type of the, script., Common uses for JavaScript are image manipulation, form, validation, and dynamic changes of content., The script below writes Hello World! to the HTML output:, Example, <script type="text/javascript">, document.write("Hello World!"), </script>, The HTML noscript Element, The <noscript> tag is used to provide an alternate content, for users that have disabled scripts in their browser or, have a browser that doesn't support client-side scripting., The noscript element can contain all the elements that, you can find inside the body element of a normal HTML, page., The content inside the noscript element will only be, displayed if scripts are not supported, or are disabled in, the user's browser:, Example, , Result, Hello World!, A browser without support for JavaScript will show the text, in the noscript element., HTML Script Tags, Tag, , Description, , <script>, , Defines a client-side script, , <noscript>, , Defines an alternate content for users, that do not support client-side scripts, , HTML Entities, Some characters are reserved in HTML., It is not possible to use the less than (<) or greater than, (>) signs in your text, because the browser will mix them, with tags., To actually display reserved characters, we must use, character entities in the HTML source code., A character entity looks like this:, &entity_name;, OR, &#entity_number;, Non-breaking Space, A common character entity used in HTML is the nonbreaking space ( )., Browsers will always truncate spaces in HTML pages. If, you write 10 spaces in your text, the browser will remove, 9 of them, before displaying the page. To add spaces to, your text, you can use the character entity., HTML Useful Character Entities, , <!DOCTYPE html>, , Note: Entity names are case sensitive!, , <html>, <body>, <script type="text/javascript">, , HTML Uniform Resource Locators, , document.write("Hello World!"), , A URL is another word for a web address., , </script>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 233
Page 753 : Result, , URL - Uniform Resource Locator, , Entity, Name, , Entity, Number, , non-breaking, space, , , ,  , , When you click on a link in an HTML page, an underlying, <a> tag points to an address on the world wide web., , <, , less than, , <, , <, , A Uniform Resource Locator (URL) is used to address a, document (or other data) on the world wide web., , >, , greater than, , >, , >, , Explanation:, , &, , ampersand, , &, , &, , •, , Scheme - defines the type of Internet service. The, most common type is http, , ¢, , cent, , ¢, , ¢, , •, , £, , pound, , £, , £, , Host - defines the domain host (the default host for, http is www), , ¥, , yen, , ¥, , ¥, , •, , Domain - defines the Internet domain name, like, w3schools.com, , •, , euro, , €, , €, , •, , §, , section, , §, , §, , Port - defines the port number at the host (the default, port number for http is 80), , ©, , copyright, , ©, , ©, , •, , ®, , registered, trademark, , ®, , ®, , Path - defines a path at the server (If omitted, the, document must be stored at the root directory of the, web site), , •, , Filename - defines the name of a document/resource, , trademark, , ™, , ™, , Description, , ™, , Common URL Schemes, , A URL can be composed of words, such as, "w3schools.com", or an Internet Protocol (IP) address:, 192.68.20.50. Most people enter the name of the website, when surfing, because names are easier to remember than, numbers., Scheme, , The table below lists some common schemes:, , Short for...., , Which pages will the scheme be used for..., , http, , HyperText Transfer Protocol, , Common web pages starts with http://. Not encrypted, , https, , Secure HyperText Transfer, Protocol, , Secure web pages. All information exchanged are encrypted, , ftp, , File Transfer Protocol, , For downloading or uploading files to a website. Useful for, domain maintenance, , file, , A file on your computer, , URL Encoding, , XML Structure, , URLs can only be sent over the Internet using the ASCII, character-set., , The XML structure including the document parts, the, prologue, and provides a simple XML example document., , Since URLs often contain characters outside the ASCII, set, the URL has to be converted into a valid ASCII format., , Document Parts, , URL encoding replaces non ASCII characters with a "%", followed by two hexadecimal digits., , •, , Prolog, , •, , Document Element (root element), , URLs cannot contain spaces. URL encoding normally, replaces a space with a + sign., 234, , The Prologue, The prologue, equivalent to the header in HTML, may, include the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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•, , •, , •, , An XML declaration (optional) such as:, , TYPES OF Web Hosting, , <?xml version="1.0"?>, , There are four types of Web hosting, , A DTD or reference to one (optional). An example, reference to an external DTD file:, , 1 Free hosting, 2 Dedicated hosting, , <!DOCTYPE LANGLIST SYSTEM "langlist.dtd">, , 3 Shared (Virtual) hosting, , Processing instructions - An example processing, instruction that causes style to be determined by a, style sheet:, , 4 Collocated Hosting, , <?xml-stylesheettype="text/css", href="xmlstyle.css"?>, An XML Example, Therefore a complete well formed XML document may look, like:, <?xml version="1.0"?>, <LAND>, <FOREST>, <TREE>Oak</TREE>, <TREE>Pine</TREE>, <TREE>Maple</TREE>, </FOREST>, <MEADOW>, <GRASS>Bluegrass</GRASS>, <GRASS>Fescue</GRASS>, , Free hosting, Free web hosting is best suited for small sites with low, traffic, like personal sites. It is not recommended for high, traffic or for real business. Technical support is often, limited, and technical options are few., Dedicated Hosting, With dedicated hosting, your web site is hosted on a, dedicated server. Dedicated hosting is the most expensive, option. This option is best suited for large web sites with, high traffic, and web sites that use special software., Dedicated hosting to be very powerful and secure, with, almost unlimited software solutions., Shared (Virtual) Hosting, Shared hosting is very cost effective., With shared hosting, your web site gets its own domain, name, and is hosted on a powerful server along with maybe, 100 other web sites. Shared solutions often offer multiple, software solutions like e-mail, database, and different editing, options. Technical support tends to be good., Collocated Hosting, , Result, , Collocation means "co-location". Collocated hosting lets, place own web server on the premises (locations) of a, service provider. This is pretty much the same as running, own server in your own office, only that it is located at a, place better designed for it. Most likely an ISP will have, dedicated resources like high-security against fire and, vandalism, regulated backup power, dedicated Internet, connections and more., , Oak Pine Maple Bluegrass Fescue Rye, , Web Server, , <GRASS>Rye</GRASS>, </MEADOW>, </LAND>, The LAND element, above, is the root element., , Web Elements, A web page, as an information set, can contain numerous, types of information, which is able to be seen, heard or, interact by the End-user, Web Hosting, A web hosting service is a type of Internet hosting service, that allows individuals and organizations to make their, Website accessible via the World Wide Web. Web hosts, are companies that provide space on a Server (computing), owned or leased for use by clients, as well as providing, Internet connectivity, typically in a data centre. Web hosts, can also provide data centre space and connectivity to, the Internet for other servers located in their data centre,, called Collocation., , A Web server is a program that, using the client server, model and the World Wide Web's Hypertext Transfer, Protocol ( HTTP), serves the files that form Web pages to, Web users (whose computers contain HTTP clients that, forward their requests). Every computer on the Internet, that contains a Web site must have a Web server program., Two leading Web servers are Apache, the most widelyinstalled Web server, and Microsoft's Internet Information, Server (IIS). Other Web servers include Novell's Web Server, for users of its Netware operating system and IBM's family, of Lotus Domino servers, primarily for IBM's OS390 and, AS-400 customers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 235
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Web servers often come as part of a larger package of, Internet- and intranet-related programs for serving e-mail,, downloading requests for File Transfer Protocol (FTP) files,, and building and publishing Web pages. Considerations, in choosing a Web server include how well it works with, the operating system and other servers, its ability to handle, server-side programming, security characteristics, and, publishing, search engine, and site building tools that may, come with it., , Application Server, Also called an appserver, and application server (Fig 16), is a program that handles all application operations, between users and an organization's backend business, applications or database. An application server is typically, used for complex transaction-based applications. To, support high-end needs, an application server has to have, built-in redundant, monitor for high-availability, highperformance distributed application services and support, for complex database access., , Fig 16, , Database Server, Database server (Fig 17) is the term used to refer to the, back-end system of a database application using client-, , 236, , server architecture. The back-end, sometimes called a, database server, performs tasks such as data analysis,, storage, data manipulation, archiving, and other non-user, specific tasks., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Designing Static WebPages, , Related Theory for Exercise 1.12.93, , Introduction to CMS and web authoring tools, Objectives: At the end of this lesson you shall be able to, • explain the meaning of content management System., • list some of the popular CMSes., • explain the use and main features of kompozer web authoring tool., Definition of CMS:, , •, , CMS Stands for "Content Management System." A CMS, is a software tool that allows you to create, edit, and publish content., , Weebly - a web-based platform for building simple personal and business websites, , •, , Wix - a collection of web publishing tools for creating a, highly customizable website, , Description of CMS:, The goal of a CMS is to provide an intuitive user interface, for building and modifying webpage content. Each CMS, also provides a web publishing tool that allows one or more, users to publish updates live on the Web. The editing component is called the content management application, (CMA), while the publishing tool is called the content delivery application (CDA). These two components are integrated together in a CMS to streamline the web development process., In terms of web publishing, content can be simple text,, photos, music, video, documents, or just about anything, you can think of. While early CMS software was used to, manage documents and local computer files, most CMS, systems are now designed exclusively to manage content on the Web. A major advantage of using a CMS is, that it requires almost no technical skill or knowledge to, manage., Content management systems are available as installable, applications and web-based user interfaces. The use of a, web interfacesimplifies the website updating process., Additionally, most web-based CMSes are updated automatically, ensuring all users have the latest tools to manage their content., A major advantage of using a CMS is that it requires almost no technical skill or knowledge to manage. Since, the CMS manages all your content, you don't have to., There are several web-based CMS tools available today., The following are some of the most popular ones:, •, , WordPress - free web software designed for creating, template-based websites or blogs, , •, , Blogger - Google's blogging tool designed specifically, for maintaining a blog, , •, , Joomla - a flexible web publishing tool that supports, custom databases and extensions, , •, , Drupal - an open source platform often used for developing community-based sites, , Introduction to WSYIWYG web authoring tools, WYSIWYG stands for "What You See Is What You Get"., In such editors you edit not directly the source code of, your documents, but its presentation as it will appear in, the final document. So instead of writing blocks of code, manually (as you e.g. would do it in Word or Notepad),, you manipulate with design components using an editor, window. This means that you view something very similar, to the final result while the document or image is being, created., There are many easy-to-use WYSIWYG programs having, all the tools needed to create a complex and fully functional websites, even by beginners. These sites even have, options to work with HTML code be it design or editing.It, is easier to create a Web site with an HTML editor, as, software developers continue to add tools that let you develop advanced features with style.Many WSYIWYG web, authoring tools offer advanced features to integrate Dynamic HTML or many other features into a site with an, elegant and consistent design., Introduction to Kompozer, KompoZer is a complete Web Authoring System that combines web file management and easy-to-use, WYSIWYGweb page editing capabilities found in Microsoft, FrontPage, Adobe DreamWeaver and other high end programs. With kompozer you can create web pages and, manage a website with no technical expertise or knowledge of HTML., A useful feature of Kompozer is that you can use it to, publish your web pages to a web hosting server. You just, need to know your FTP account username and password, as well as the site URL and Kompozer will log in and, place your web pages on the server., KompoZer's File Menu contains menu items for all major, operations possible while using it. KompoZer's tool bar, user interface consists of:, , Copyright @ NIMI Not to be Republished, , 237
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Composition Toolbar, , •, , Format Toolbar, , •, , Tab Browser Toolbar, , •, , Edit Mode Toolbar, , •, , Status Toolbar, , Edit Mode Toolbar(Refer Fig.4), The Edit Mode Toolbar indicates the viewing mode which, is presently active for the current document. Available viewing modes are the Normal view, HTML Tags view, HTML, source view and the Preview mode. You can easily change, your viewing mode by simply clicking any of the other, three with the mouse., , Composition Toolbar, The Composition Toolbar consists of buttons for the most, used major operations. Below is the a snapshot of the, default Composition Toolbar with text below each button, indicating the respective button's function. (Refer Fig.1), copa 1308201, , Fig 1, , Format Toolbar(Refer Fig.2), , copa 1308204, , Status Toolbar(Refer Fig.5), KompoZer's status bar shows the position of the cursor, with respect to the HTML tag hierarchy. You can easily, edit/assign the properties of any particular tag in the status bar just by right clicking and choosing the desired, option. Simple left-click of the mouse on a tag in status, bar selects the text surrounded by that tag., Fig 5, , copa 1308202, , The Format Toolbar is a very useful tool while editing web, pages with KompoZer. With the Format Toolbar you can, apply paragraph format, choose a font, change foreground, or background colour, increase or decrease size, and, emphasize a block of text. You can also create ordered or, unordered lists and justify a block of text to left, right or, centre. To know which button does what just hover your, mouse over the button and a tool tip will appear indicating, the function of the button., , Fig 4, , Fig 2, , Tab Browser Toolbar(Refer Fig.3), KompoZer allows you to simultaneously edit multiple web, documents using different tabs for each opened document., Having multiple tabs gives a cleaner look to your desktop, as it is not cluttered when multiple windows are used for, each document. As a visual indicator a "red floppy icon", icon appears for pages which have been edited but not, saved yet., Fig 3, copa 1308203, , 238, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.93, , Copyright @ NIMI Not to be Republished, , copa 1308205, , •
Page 758 : Sector, , : IT & ITES, , Duration : 1 - Year, Trade, , Copyright, , : Computer Operator and Programming Assistant 1st Semester - Trade Theory, NSQF level 4, , 2018 National Instructional Media Institute, Chennai, , First Edition :, Second Edition :, , September 2018, December 2018, , Copies : 1,000, Copies :1,000, , Rs. 255 /-, , All rights reserved., No part of this publication can be reproduced or transmitted in any form or by any means, electronic or mechanical, including, photocopy, recording or any information storage and retrieval system, without permission in writing from the National, Instructional Media Institute, Chennai., , Published by:, NATIONAL INSTRUCTIONAL MEDIA INSTITUTE, P. B. No.3142, CTI Campus, Guindy Industrial Estate,, Guindy, Chennai - 600 032., Phone : 044 - 2250 0248, 2250 0657, 2250 2421, Fax : 91 - 44 - 2250 0791, email :
[email protected],
[email protected], Website: www.nimi.gov.in, (ii), , Copyright @ NIMI Not to be Republished
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FOREWORD, , The Government of India has set an ambitious target of imparting skills to 30 crores people, one out of every, four Indians, by 2020 to help them secure jobs as part of the National Skills Development Policy. Industrial, Training Institutes (ITIs) play a vital role in this process especially in terms of providing skilled manpower., Keeping this in mind, and for providing the current industry relevant skill training to Trainees, ITI syllabus, has been recently updated with the help of Mentor Councils comprising various stakeholder's viz. Industries,, Entrepreneurs, Academicians and representatives from ITIs., The National Instructional Media Institute (NIMI), Chennai, has now come up with instructional material to, suit the revised curriculum for Computer Operator and Programming Assistant Trade Theory 1st, Semester in IT & ITES Sector . The NSQF Level - 4 Trade Theory will help the trainees to get an international, equivalency standard where their skill proficiency and competency will be duly recognized across the globe, and this will also increase the scope of recognition of prior learning. NSQF Level - 4 trainees will also get, the opportunities to promote life long learning and skill development. I have no doubt that with NSQF Level, - 4 the trainers and trainees of ITIs, and all stakeholders will derive maximum benefits from these IMPs and, that NIMI's effort will go a long way in improving the quality of Vocational training in the country., The Executive Director & Staff of NIMI and members of Media Development Committee deserve appreciation, for their contribution in bringing out this publication., Jai Hind, , RAJESH AGGARWAL, , Director General/ Addl. Secretary, Ministry of Skill Development & Entrepreneurship,, Government of India., , New Delhi - 110 001, , (iii), , Copyright @ NIMI Not to be Republished
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PREFACE, The National Instructional Media Institute (NIMI) was established in 1986 at Chennai by then Directorate, General of Employment and Training (D.G.E & T), Ministry of Labour and Employment, (now under Directorate, General of Training, Ministry of Skill Development and Entrepreneurship) Government of India, with technical, assistance from the Govt. of the Federal Republic of Germany. The prime objective of this institute is to, develop and provide instructional materials for various trades as per the prescribed syllabi under the Craftsman, and Apprenticeship Training Schemes., The instructional materials are created keeping in mind, the main objective of Vocational Training under, NCVT/NAC in India, which is to help an individual to master skills to do a job. The instructional materials are, generated in the form of Instructional Media Packages (IMPs). An IMP consists of Theory book, Practical, book, Test and Assignment book, Instructor Guide, Audio Visual Aid (Wall charts and Transparencies) and, other support materials., The trade practical book consists of series of exercises to be completed by the trainees in the workshop., These exercises are designed to ensure that all the skills in the prescribed syllabus are covered. The trade, theory book provides related theoretical knowledge required to enable the trainee to do a job. The test and, assignments will enable the instructor to give assignments for the evaluation of the performance of a trainee., The wall charts and transparencies are unique, as they not only help the instructor to effectively present a, topic but also help him to assess the trainee's understanding. The instructor guide enables the instructor to, plan his schedule of instruction, plan the raw material requirements, day to day lessons and demonstrations., IMPs also deals with the complex skills required to be developed for effective team work. Necessary care, has also been taken to include important skill areas of allied trades as prescribed in the syllabus., The availability of a complete Instructional Media Package in an institute helps both the trainer and, management to impart effective training., The IMPs are the outcome of collective efforts of the staff members of NIMI and the members of the Media, Development Committees specially drawn from Public and Private sector industries, various training institutes, under the Directorate General of Training (DGT), Government and Private ITIs., NIMI would like to take this opportunity to convey sincere thanks to the Directors of Employment & Training, of various State Governments, Training Departments of Industries both in the Public and Private sectors,, Officers of DGT and DGT field institutes, proof readers, individual media developers and coordinators, but for, whose active support NIMI would not have been able to bring out this materials., , R. P. DHINGRA, EXECUTIVE DIRECTOR, , Chennai - 600 032, , (iv), , Copyright @ NIMI Not to be Republished
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INTRODUCTION, TRADE THEORY, The manual of trade theory consists of theorectical information for the First Semester couse of the COPATrade., The contents are sequenced accoring to the practical exercise contained in the manual on Trade practical., Attempt has been made to relate the theortical aspects with the skill covered in each exercise to the extent, possible. This co-relation is maintained to help the trainees to develop the perceptional capabilities for, performing the skills., The Trade Theory has to be taught and learnt along with the corresponding exercise contained in the manual, on trade practical. The indicating about the corresponding practical exercise are given in every sheet of this, manual., It will be preferable to teach/learn the trade theory connected to each exercise atleast one class before, performing the related skills in the system lab. The trade theory is to be treated as an integrated part of each, exercise., The material is not the purpose of self learning and should be considered as supplementary to class room, instruction., TRADE PRACTICAL, The trade practical manual is intented to be used in workshop . It consists of a series of practical exercies to, be completed by the trainees during the First Semester course of the COPA trade supplemented and, supported by instructions/ informations to assist in performing the exercises. These exercises are designed, to ensure that all the skills in the prescribed syllabus are covered., The manual is divided into twelve modules to maintain completancy of leaning process in a stipulated time, basis., The skill training in the computer lab is planned through a series of practical exercises centred around some, practical project. However, there are few instance where the individual exercise does not form a part of project., While developing the practical manual a sincere effort was made to prepare each exercise which will be easy, to understand and carry out even by below average traninee. However the development team accept that there, if a scope for further improvement. NIMI, looks forward to the suggestions from the experienced training faculty, for improving the manual., , (vi), , Copyright @ NIMI Not to be Republished
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CONTENTS, Lesson No., , Title of the Lesson, , Page No., , Module 1: Safe working practices, 1.1.01 &1.1.02, , Electrical safety, , 1, , 1.1.03 & 1.1.04, , Safety practices, fire extinguishers, , 2, , Module 2: Introduction to computer components, 1.2.05, , Introduction to computers, , 7, , 1.2.06, , Introduction to CPU architecture and mother board, , 17, , Module 3: Windows operating system, 1.3.07 -1.3.11, , Windows operating system, , 25, , 1.3.12, , Handling printers, , 33, , Module 4: Computer basics and software installation, 1.4.13, , CMOS setup and windows installation, , 36, , 1.4.14 & 1.4.15, , CMOS setup and windows installation, , 38, , 1.4.16, , Troubleshooting computer, , 42, , 1.4.17, , Application Softwares, , 47, , 1.4.18 & 1.4.19, , Bluetooth devices, , 49, , 1.4.20, , DVDs, CDs and burning DVDs, , 51, , Module 5: Dos & LInux operating systems, 1.5.21, , Comand line interface with DOS, , 53, , 1.5.22, , Methods to display the contents of a text file, , 56, , 1.5.23, , Introduction to Linux operating system, , 60, , 1.5.24 - 1.5.26, , Handling commands and various editors, , 63, , 1.5.27 - 1.5.28, , Managing files and directories, , 80, , Module 6: Word Processing Software, 1.6.29, , MS word 2010 Theory, , 113, , 1.6.30 - 1.6.37, , Creating a file, save and other options, , 117, , 1.6.38, , Typing practice using open source typing tutor tools, , 123, , (vii), , Copyright @ NIMI Not to be Republished
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Lesson No., , Title of the Lesson, , Page No., , Module 7: Spread sheet Application, 1.7.39 - 1.7.41, , Introduction to MS - Excel 2010, , 124, , 1.7.42 - 1.7.46, , Functions and formulas in MS- Excel 2010, , 133, , 1.7.47 - 1.7.48, , Data validations and Table management in Ms Excel 2010, , 138, , Module 8: Image Editing, presentations, 1.8.49 - 1.8.57, , Image editing, presentations, , 145, , Module 9: Database Management Systems, 1.9.58 - 1.9.61, , Concepts of data and Databases, , 152, , 1.9.62 - 1.9.66, , Forms, quires, and reports in access, , 163, , Module 10: Networking concepts, 1.10.67 - 1.10.69, , Concepts of network and internet, , 169, , 1.10.70, , Introduction to TCP/IP, , 188, , 1.10.71 & 1.10.72, , Transmission media and network components, , 190, , 1.10.73A, , Computer name and workgroup, , 197, , 1.10.73B, , Concept of proxy server, , 200, , 1.10.74, , Video conferencing, , 202, , 1.10.75, , Network security, , 203, , Module 11: Internet Concepts, 1.11.76 & 1.11.77, , E- mail, , 205, , 1.11.78, , Chatting,video chatting and using social network sites, , 209, , 1.11.79, , Explaining threats to computers connected to Internet & process, , 210, , 1.11.80 & 1.11.81, , Outlook Express & Google+, , 213, , Module 12: Designing Static Webpages, 1.12.82 - 1.12.92, , Web designing, , 214, , 1.12.93, , Introduction to CMS and web authoring tools, , 237, , (viii), , Copyright @ NIMI Not to be Republished
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LEARNING / ASSESSABLE OUTCOME, On completion of this book you shall be able to, • Install and setup operating system and related software in a, computer., • Create, format and edit document using word processing application software., • Create, edit and develop a workbook by using spreadsheet application software., • Create and customize slides for presentation., • Create and manage database file by using MS Access, • Install, setup/ configure, troubleshoot and secure computer network including Internet., • Develop static webpages using HTML., , (ix), , Copyright @ NIMI Not to be Republished
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SYLLABUS, First Semester, Week, No., 1., , Duration: Six Month, , Ref. Learning, Outcome, , •, , Apply safe working, practices, , • Install and setup, , operating system, and related software, in a computer., , Professional Skills, (Trade Practical), with Indicative hours, , Safe working practices, Safe working practices, • Scope of the COPA trade., 1. Visit COPA Lab. of the institutes and, locate the electrical connections with • Safety rules and safety signs., computer system setup (6 hrs), • Types and working of fire, 2. Identifying safety symbols and, extinguishers., hazard identification.(4 Hrs), Introduction to Computer, 3. Practice safe methods of fire fighting in, components, case of electrical fire. (4 hrs), • Introduction to computer, 4. Use of fire extinguishers. (4 Hrs), system. Concepts of hardward, Computer components, and Software., 5. Identify computer peripherals and, •, Function of motherboard, internal components of a disassembled, components and various, desktop computer. (6 Hrs), processors., 6. Assemble components of desktop, computer. (6 Hrs), • Various Input / Output devices, in use and their features., , 2., , • Install and setup, , Using Windows Operating System, 7. Practice on Windows interface, and navigating windows. (9 Hrs), 8. Practice on managing files and, folders using removable drives. (6 Hrs), 9. Customize the desktop settings, and manage user accounts. (6 Hrs), 10. View system properties and control, panel details. (6 Hrs), 11. Work with keyboard shortcut commands., (6 Hrs), 12. Print and scan document using different, commands.(3 Hrs), , 3., , • Install and setup, , Computer basics and Software, Installation, 13. View the BIOS settings and their, modifications. (3 Hrs), 14. Install Windows OS (5 Hrs), 15. Format Hard Disk and create, partition (3 Hrs), 16. Identify and rectify common, hardware and software issues, during OS installation. (4 Hrs), 17. Install necessary application, software for Windows i.e. Office, Package, PDF Reader, Media, Player etc. (5 Hrs), 18. Configure Bluetooth and wi-fi, settings. (3 Hrs), 19. Install Drivers for printer, scanner,, webcam and DVD etc. (4 Hrs), 20. Burn data, video and audio files on, CD/DVD using application, software. (3 Hrs), , operating system, and related software, in a computer., , operating system and, and related software, in a computer., , Professional Knowledge, (Trade Theory), , COPA 1st semester, , Introduction Windows, Operating System, • Introduction to operating, System, • Main features of Windows, OS, • Concept of various shortcut, commands., , Computer basics and Software, Installation, • Introduction to the booting, process., • Introduction to various, types of memories and their, features., • Basic Hardware and, software issues and their, solutions., • Usage of Application, software and Antivirus., , Copyright @ NIMI Not to be Republished
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• Install and, , DOS Command Line Interface & Linux, Operating Systems, 21. Use basic DOS commands for directory listing (10 hrs), 22. Manage files and folders using DOS commands (6 hrs), 23. Install Linux operating system.(6 Hrs), 24. Install necessary application software for Linux i.e., Office Package, PDF Reader, MediaPlayer etc. (6 Hrs), 25. Use Basic Linux commands for directory listing, file, and folder management, password etc. (10Hrs), 26. Use the Linux GUI for file and folder management,, exploring the system etc. (10 Hrs), 27. Customize desktop settings and manage user, accounts in Linux. (6 Hrs), 28. View system properties and manage system setting, in Linux (6 Hrs), , 6-8, , Create, format, and edit, document using, word, processing, application, software., , Word Processing, Using Word Processing Software, 29. Open MS Word and familiarise with basic word Software, components. (3 Hrs), • Introduction to the various, 30. Practice creating, saving and renaming of word, applications in MS office., documents.(3 Hrs), • Introduction to Word, 31. Edit document using basic formatting tools. (8 Hrs), features,, 32. Practice Inserting and formatting tables and other, Office button, toolbars., objects. (12 Hrs), • Creating, saving and, 33. Work with Page layout settings and printing, formatting, documents. (6 Hrs), and printing documents, 34. Use templates, autocorrect tools, and record and, using Word., execute a macro. (6 Hrs), 35. Use Mail merge tool. Use conditional Mail Merge, • Working with objects,, macro, mail merge,, External Data Source. Practice Letters, Label &, templates and other tools, Envelop printing using Mail Merge (10 Hrs)., in Word., 36. Use Table of Context, Indexing, Hyperlink, Bookmark,, Comment, equation,symbols,citation, crossreference,, footnote, translate, synonyms, thesaurus, spell, check & grammer, compare etc. ( 6 Hrs ), 37. Practice Typing using open source tutor. (24 Hrs), 38. Practice of using shortcut keys and use Open Office, as word processor. (12 Hrs), , 9 - 11, , • Create,, , 4-5, , setup OS, and related, software in a, computer., , Introduction to DOS, Command, Line Interface & Linux, Operating, Systems, • Introduction to basic DOS, Internal and External, Commands., • Introduction to Open, Source Software., • Introduction to Linux, Operating System features,, structure,, files, and, processes., • Basic Linux commands., , Using Spread Sheet Application, Spread Sheet Application, 39. Open MS Excel and familiarise with basic application • Introduction to Excel, format,, components. (4 Hrs), edit and, features and Data Types., 40., Practice, create, save and format excel sheets. (9 Hrs), develop, • Cell referencing and, a workbook by 41. Use absolute and relative referencing, linking sheets,, linking, conditional formatting etc. (9 Hrs), using, Sheets., spreadsheet 42. Practice Excel functions of all major categories i.e. • Introduction to various, Financial, Logical, Text, date & time, Lookup, Math,, application, functions in all categories, Statistical etc. (12 Hrs), software., of Excel., 43. Use various data types in Excel, sorting, filtering and, • Concepts of sorting,, validating data. (8 Hrs), 44. Create and format various static and dynamic charts., filtering, (10 Hrs), and validating data., 45. Practice Importing & exporting excel data. (4 Hrs), • Analyzing data using, 46. Perform data analysis using “what if” tools and Pivot, charts, data tables, pivot, Table and record and execute a macro. (10 Hrs), tables, goal seek and, 47. Modify Excel page setup and printing and use open, scenarios., office as Spreadsheet application. (4 Hrs), 48. Execute simple projects using Excel & Word. (20 Hrs), , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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12 - 13, , Create and, customize, slides for, presentation., , 14 - 15, , Create and, manage, database, file by, using MS, Access., , 16 - 17, , Install,, setup/, configure,, troubleshoot, and secure, computer, network, including, Internet., , Image editing and creating, Presentations, 49. Use Windows Paint or image editing, software like Open Office Draw, GIMP,, IrfanView or a similar tool. (6 Hrs), 50. Perform Image editing using open, source applications. (12 Hrs), 51. Open power point presentation, and familiarise with basic, application components. (6 Hrs), 52. Create Slide shows, Insert picture, and theme. (6 Hrs), 53. Add new slide, format text, link with word, and excel documents. (5 Hrs), 54. Practice animating slide transitions and, objects. (4 Hrs), 55. Create slide shows by inserting audio &, video and sync with presentation. (6 Hrs), 56. Modify slide page setup and print, the slides. (3 Hrs), 57. Create a simple presentation, project using open office. (12 Hrs), Database Management with MS Access, 58. Create database and design a simple tables, in Access. (6 Hrs), 59. Practice enforcing integrity constraints and, modify properties of tables and fields. (6, Hrs), 60. Create relationships and join tables. (6 Hrs), 61. Create and format Forms. (6 Hrs), 62. Create simple queries with various criteria, and calculations. (12 Hrs), 63. Create Simple update, append, make table,, delete and crosstab queries. (9 Hrs), 64. Modify form design with controls, macros, and events. (6 Hrs), 65. Import and export data to/from Access and, create and format types of reports. (6 Hrs), 66. Compress and Encrypt databases. (3 Hrs), , Image editing, Presentations, • Introduction to Open Office., • Introduction to the, properties and editing of, images., • Introduction to different, formats of images and their, uses., • Introduction to Power Point, and its advantages., • Creating Slide Shows., • Fine tuning the, presentation and good, presentation technique., , Database Management Systems, • Concepts of Data and Databases., • Overview of popular databases,, RDBMS, OODB and NOSQL., • Rules for designing good tables., Integrity rules and constraints in, a table., • Relationships in tables., • Introduction to various types of, Queries and their uses., • Designing Access Reports and, Forms., • Introduction to macros, designer, objects controls, their properties, and behaviour., , Configuring and using Network, Networking Concepts, 67. View Network connections. (3 Hrs), • Introduction to Computer Networks,, 68. Connect a computer to a n/w and share, Necessity and Advantages., Devices i.e. Printers, files, folders and, • Client Server and peer to Peer, drives. (6 Hrs), networking concepts., 69. Work with various Network devices,, •, Concept of Proxy Server and proxy, connectors/cables. Create straight/cross, firewall server., cable and punch a UTP cable in the patch, • Concept of DHCP Server., socket and test the connectivity. (6 Hrs), 70. Practice IP Addressing and Subnet masking • Introduction to LAN, WAN and MAN., for IPV4/ IPV6 and pinging to test networks. • Network topologies. Network, (6 Hrs), components, viz. Modem, Hub,, 71. Configure Hub and Switch. (6 Hrs), Switch, Router,Bridge, Gateway etc., 72. Set up and configure wired and wireless, • Network Cables, Wirelessnetworks, LAN in a Computer Lab within at least three, and Blue Tooth technology., computers. Use patch panel & I/O Box for, •, Concept of ISO - OSI 7 Layer Model., wired LAN and installing & configuring, Internet connection in a single PC and in a • Overview of Network protocols, Viz.TCP/IP, FTP, Telnet etc., LAN. (12 Hrs), COPA1st semester, , Copyright @ NIMI Not to be Republished
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73. Setup a proxy server/DHCP Server with firewall.(9 Hrs), 74. Setup video conferencing using open source s/w(6 Hrs), 75. Use various tools (by open source /free) for network, troubleshooting, maintenance and security for both, Wired and Wireless(6 Hrs), 18, , • Concept of Logical and, , Physical Addresses,, Subnetting and Classes of, Networks., , Using Internet, Install,, Internet Concepts, 76. Browse the Internet for information (use at least 3 • Introduction to www,, setup/, popular browsers). (3 Hrs), configure,, Concept of Internet, Web, troubleshoot 77. Create and use e-mail for communication with, Browsers, internet servers, attachment, priority setting, address book. (3 Hrs), and secure, and search engines., 78. Communicate with text, video chatting and social, computer, •, Concepts of Domain naming, networking sites. (6 Hrs), network, Systems and E mail, 79. Use online dictionary, translation software, storage, including, communication., space, share files with e-mail links, download manager,, Internet., •, Introduction to video chatting, download & upload YouTube files, google map & earth, tools and Social Networking, etc. Update windows & other software. (6 Hrs), concepts., 80. Configure Outlook, mail service in mobile phones. Use, tools like Skype, Google+ etc. (6 Hrs), 81. Browser setting for Bookmark, cookies, favourites and, pop ups, default website, trusted site,restricted site,, content, history and advanced setup. (6 Hrs ), , Web Design Concepts, Designing Static Web Pages, 19-21 Develop, 82. Practice with basic HTML elements (e.g. head, title, • Concepts of Static and, static, body), tag and attributes. (3 Hrs), Dynamic Web pages., web pages, 83. Design simple web page with text, paragraph and line • Introduction to HTML and, using, break usingHTML tags. (5 Hrs), HTML., various tags in HTML., 84. Format text, change background colour and insert, • Concepts of different, pictures in web page. (6 Hrs), controls used in Web Pages., 85. Design simple web page with tables and lists. (6 Hrs), 86. Use marquees, hyperlinks and mailto link in designing • Concepts of CSS and, applying CSS to HTML., web pages.(6 Hrs), •, Introduction to open source, 87. Create frames, add style and design layout. (10 Hrs), CMS viz, Joomla, Word, 88. Insert text, check and combo box in web page. (6 Hrs), press etc. and Web, 89. Design web page using password field, submit button,, authoring tools viz., reset button and radio button etc. (6 Hrs), Kompozer, Front Page etc., 90. Design a web page adding flash file, audio and video, files. (10 Hrs), • Concept of good web page, 91. Design web page with forms and form controls using, designing techniques., HTML tags.(8 Hrs), 92. Create web page using Cascading Style Sheet (CSS)., (12 Hrs), 93. Use WYSIWYG (Kompozer) web design tools to, design and edit web pages with various styles. (12Hrs), 22-23 Industrial Visit/Project work, 1. Create a simple web site of at least 5 web pages which will include Images, tables, charts, lists and, hyperlink on any topic like Student Information System, Book Store, and Organisations etc., OR, 2. Setup and configure a LAN using at least 3 computers connected with wire and 3 computers connected, with wireless and secure it.), 24-25, 26, , Revision, Examination, , COPA 1st semester, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.01 &1.1.02, , Electrical safety, Objective : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire., The severity of an electric shock will depend on the level of, current which passes through the body and the length of, time of contact. Do not delay, act at once. Make sure that, the electric current has been disconnected., , If the casualty is unconscious but is breathing, loosen the, clothing about the neck, chest and waist and place the, casualty in the recovery position.( Fig 3), , If the casualty is still in contact with the supply - break the, contact either by switching off the power, removing the plug, or wrenching the cable free. If not, stand on some insulating, material such as dry wood, rubber or plastic, or using, whatever is at hand to insulate yourself and break the, contact by pushing or pulling the person free. (Figs 1 & 2), If you remain un-insulated, do not touch the victim with your, bare hands until the circuit is made dead or person is, moved away from the equipment., , Keep a constant check on the breathing and pulse rate., Keep the casualty warm and comfortable. (Fig 4), Send for help., Do not give an unconscious person anything by, mouth., Do not leave an unconscious person unattended., If the casualty is not breathing - Act at once - don’t waste, , If the victim is aloft, measures must be taken to prevent him, from falling or atleast make him fall safe., Electric burns on the victim may not cover a big area but, may be deep seated. All you can do is to cover the area, with a clean, sterile dressing and treat for shock. Get, expert help as quickly as possible., , Copyright @ NIMI Not to be Republished, , 1
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IT & ITES, COPA - Safe working practices, , Related Theory for Exercise 1.1.03 & 1.1.04, , Safety practice - fire extinguishers, Objectives : At the end of this lesson you shall be able to, • explain how to rescue a person who is in contact with a live wire, • distinguish the different types of fire extinguishers, • determine the correct type of fire extinguisher to be used based on the class of fire, • describe the general procedure to be adopted in the event of a fire., Fire is the burning of combustible material. A fire in an, unwanted place and on an unwanted occasion and in an, uncontrollable quantity can cause damage or destroy, property and materials. It might injure people, and, sometimes cause loss of life as well. Hence, every effort, must be made to prevent fire. When a fire outbreak is, discovered, it must be controlled and extinguished by, immediate corrective action., Is it possible to prevent fire? Yes, fire can be prevented by, eliminating anyone of the three factors that causes fire., The following are the three factors that must be present in, combination for a fire to continue to burn. (Fig 1), , Accumulation of combustible refuse (cotton waste soaked, with oil, scrap wood, paper, etc.) in odd corners are a fire, risk. Refuse should be removed to collection points., The cause of fire in electrical equipment is misuse or, neglect. Loose connections, wrongly rated fuses, overloaded, circuits cause overheating which may in turn lead to a fire., Damage to insulation between conductors in cables causes, fire., Clothing and anything else which might catch fire should be, kept well away from heaters. Make sure that the heater is, shut off at the end of the working day., Highly flammable liquids and petroleum mixtures (thinner,, adhesive solutions, solvents, kerosene, spirit, LPG gas, etc.) should be stored in the flammable material storage, area., Blowlamps and torches must not be left burning when they, are not in use., Extinguishing fires: Fires are classified into four types in, terms of the nature of fuel., , Fuel: Any substance, liquid, solid or gas will burn, if there, is oxygen and high enough temperatures., Heat: Every fuel will begin to burn at a certain temperature., It varies and depends on the fuel. Solids and liquids give off, vapour when heated, and it is this vapour which ignites., Some liquids do not have to be heated as they give off, vapour at normal room temperature say 150C, eg. petrol., Oxygen: Usually exists in sufficient quantity in air to keep, a fire burning., Extinguishing of fire: Isolating or removing any of these, factors from the combination will extinguish the fire. There, are three basic ways of achieving this., •, , Starving the fire of fuel removes this element., , •, , Smothering - ie. isolate the fire from the supply of, oxygen by blanketing it with foam, sand etc., , •, , Cooling - use water to lower the temperature. Removing, any one of these factors will extinguish the fire., , Different types of fires (Fig 2, Fig 3 Fig 4 & Fig 5) have to, be dealt with in different ways and with different extinguishing, agents., An extinguishing agent is the material or substance used, to put out the fire, and is usually (but not always) contained, in a fire extinguisher with a release mechanism for spraying, into the fire., It is important to know the right type of agent for extinguishing, a particular type of fire; using a wrong agent can make, things worse.There is no classification for ‘electrical fires’, as such, since these are only fires in materials where, electricity is present., , Preventing fires: The majority of fires begin with small, outbreaks which burn unnoticed until they have a secure, hold. Most fires could be prevented with more care and by, following some simple common sense rules., 2, , Copyright @ NIMI Not to be Republished
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Fuel, , Extinguishing, Most effective ie. cooling with water. Jets of water, should be sprayed on the base of the fire and then, gradually upwards., , Should be smothered. The aim is to cover the entire, surface of the burning liquid. This has the effect of, cutting off the supply of oxygen to the fire., Water should never be used on burning liquids., Foam, dry powder or CO2 may be used on this type, of fire., , Extreme caution is necessary in dealing with liquefied, gases. There is a risk of explosion and sudden, outbreak of fire in the entire vicinity. If an appliance, fed from a cylinder catches fire - shut off the supply, of gas. The safest course is to raise an alarm and, leave the fire to be dealt with by trained personnel., Dry powder extinguishers are used on this type of, fire., , Special powders have now been developed which, are capable of controlling and/or extinguishing this, type of fire., The standard range of fire extinguishing agents is, inadequate or dangerous when dealing with metal, fires., Fire on electrical equipment., Halon, Carbon dioxide, dry powder and vapourising, liquid (CTC) extinguishers can be used to deal with, fires in electrical equipment. Foam or liquid (eg., water) extinguishers must not be used on electrical, equipment under any circumstances., , IT & ITES : COPA - Related Theory for Exercise 1.01.01 & 1.01.02, , Copyright @ NIMI Not to be Republished, , 3
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Many types of fire extinguishers are available with different, extinguishing ‘agents’ to deal with different classes of fires., (Fig 1), , Dry powder extinguishers (Fig 4): Extinguishers fitted, with dry powder may be of the gas cartridge or stored, pressure type. Appearance and method of operation is the, same as that of the water-filled one. The main distinguishing feature is the fork shaped nozzle. Powders have been, developed to deal with class D fires., , Water-filled extinguishers: There are two methods of, operation. (Fig 2), , Carbon dioxide (CO2): This type is easily distinguished, by the distinctively shaped discharge horn. (Fig 5)., , •, , Gas cartridge type, , •, , Stored pressure type, , With both methods of operation the discharge can be, interruted as required, conserving the contents and, preventing unnecessary water damage., Foam extinguishers (Fig 3):These may be of stored, pressure or gas cartridge types. Always check the operating, instructions on the extinguisher before use., , Suitable for Class B fires. Best suited where contamination, by deposits must be avoided. Not generally effective in, open air., Always check the operating instructions on the container, before use. Available with different gadgets of operation, such as - plunger, lever, trigger etc., Halon extinguishers (Fig 6): These extinguishers may be, filled with carbon-tetrachloride and Bromochlorodifluoro, methene (BCF). They may be either gas cartridge or stored, pressure type., , Most suitable for, • flammable liquid fires, •, , running liquid fires., , Must not be used on fires where electrical equipment is, involved., , 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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They are more effective in extinguishing small fires involving, pouring liquids. These extinguishers are particularly suitable, and safe to use on electrical equipment as the chemicals, are electrically non-conductive., The fumes given off by these extinguishers are, dangerous, especially in confined space., The general procedure in the event of a fire:, •, , Raise an alarm., , •, , Turn off all machinery and power (gas and electricity)., , •, , Close the doors and windows, but do not lock or bolt, them. This will limit the oxygen fed to the fire and prevent, its spreading., , •, , Try to deal with the fire if you can do so safely. Do not, risk getting trapped., , •, , Anybody not involved in fighting the fire should leave, calmly using the emergency exits and go to the, designated assembly point. Failure to do this may, mean that some person being unaccounted for and, others may have to put themselves to the trouble of, searching for him or her at risk to themselves., , Practice on fire extinguishers, Objectives: At the end of this lesson you shall be able to, • state about the selection of the fire extinguishers according to the type of fire, • state the method of operation of the fire extinguisher, • explain how to extinguish the fire., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished, , 5
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PROCEDURE (Fig 1), , •, , •, , Alert people sorrounding by shouting fire, fire, fire when, observe the fire., , •, , Inform fire service or arrange to inform immediately., , •, , Open emergency exist and ask them to go away., , •, , Put “off” electrical power supply., , Aim the extinguisher nozzle or hose at the base of the, fire (this will remove the source of fuel fire) (Fig 4), , Don’t allow people to go nearer to the fire, •, , Analyze and identify the type of fire. Refer Table1., Table-1, Class ‘A’, , Wood, paper, cloth,, solid material, , Class ‘B’, , Oil based fire (grease,, gasoline, oil) liquefiable, gases, , Class ‘C’, , Gas and liquefiable, , Keep your self low, •, , Squeeze the handle lever slowly to discharge the agent, (Fig 5), , •, , Sweep side to side approximately 15 cm over the fuel, fire until the fire is put off (Fig 5), , gases, Class ‘D’, , Metals and electrical, equipment, , Assume the fire is ‘B; type (flammable liquifable solids), •, , Slect CO2 (Carbon di oxide) fire extinguisher., , •, , Locate and pickup, CO2 fire extinguisher. Click for its, expiry date., , •, , Break the seal (Fig 2), Fire extinguishers are manufactured for use, from the distance., Caution, • While putting off fire, the fire may flare up, • Do not be panick belong as it put off promptly., • If the fire doesn’t respond well after you have, used up the fire extinguisher move away yourself, away from the fire point., , •, , Pull the safety pin from the handle (Pin located at the, top of the fire extinguisher) (Fig 3), , • Do not attempt to put out a fire where it is, emitting toxic smoke leave it for the professionals., • Remember that your life is more important than, property. So don’t place yourself or others at risk., In order to remember the simple operation of the, extinguisher. Remember P.A.S.S. This will help, you to use the fire extinguisher., P for Pull, A for Aim, S for Squeeze, S for Sweep, , 6, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.01.03, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.2.05, COPA - Introduction to computer components, Introduction to computers, Objectives : At the end of this lesson you shall be able to, • define and classify computers, • list the advantages and limitations of computers, • list the applications of computer, • describe the voltages and currents in the computer., Computer - Definitions, , Fig 1, , A computer is an electronic machine, operating under, the control of instructions stored in its own memory that, can accept data (input), manipulate the data according, to specified rules (process), produce results (output), and, store the results for future use., Technically, a computer is a programmable machine., This means it can execute a list of programmed, instructions and respond to new instructions that it is, given., History of Computer, Charles babbbage’s machine, , The Analytical Engine had four parts. A mill, which was, the section which did the calculations, essentially the, CPU; the store, were the information was kept recorded,, essentially the memory; the reader, which would allow, data to be entered using punched cards, essentially the, keyboard, and the printer., Hence, Charles Babbage is considered as the "Father, of the Computer" as in fig-1., The generations of computers are characterized by a, major technological development that fundamentally, changed the way computers operate, resulting in, increasingly smaller, cheaper, more powerful and more, efficient and reliable devices. The various generations, of computers are listed below:, First Generation (1946-1954): In 1946 the digital, computer using electronic valves (Vacuum tubes) are, known as first generation computers. The first 'computer', to use electronic valves i.e. vacuum tubes. The high, cost of vacuum tubes prevented their use for main, memory. They stored information in the form of, propagating sound waves., The vacuum tube consumes a lot of power. These, computers were large in size and writing programs on, them was difficult. Some of the computers of this, generation were:, , CP110111, , The working principles of today's computers were, provided by an English mathematician Charles Babbage, around 1833's invented a machine called the "Analytical, Engine". A machine which could calculate and print tables, of functions using limited techniques., , Mark I :The IBM Automatic Sequence Controlled, Calculator (ASCC), called the Mark I by Harvard, University, was an electro-mechanical computer. Mark, I is the first machine to successfully perform a long, services of arithmetic and logical operation. Mark I is, the First Generation Computer., ENIAC: It was the first electronic computer built in 1946, at University of Pennsylvania, USA by John Eckert and, John Mauchy. It was named Electronic Numerical, Integrator and Calculator (ENIAC). The ENIAC was 3050 feet long, weighted 30 tons, contained 18,000 vacuum, tubes, 70,000 resisters, 10,000 capacitors and required, 150,000 watts of electricity. Today computer is many, times as powerful as ENIAC, still size is very small., EDVAC: It stands for Electronic Discrete Variable, Automatic Computer and was developed in 1950. The, concept of storing data and instructions inside the, computer was introduced here. This allowed much faster, operation since the computer had rapid access to both, data and instructions. The other advantage of storing, instruction was that computer could do logical decision, internally. The EDVAC was a binary serial computer, with automatic addition, subtraction, multiplication,, programmed division and automatic checking with an, ultrasonic serial memory., , Copyright @ NIMI Not to be Republished, , 7
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EDSAC: It stands for Electronic Delay Storage, Automatic Computer and was developed by M.V., Wilkes at Cambridge University in 1949. The EDSAC, is the first stored-program computer. The EDSAC, performed computations in the three millisecond range., It performed arithmetic and logical operations without, human intervention. The key to the success was in the, stored instructions which it depended upon solely for its, operation., , • Transistors were used instead of Vacuum Tube., • Processing speed is faster than First Generation, Computers (Micro Second), , • Smaller in Size (51 square feet), • The input and output devices were faster., , This machine marked the beginning of the computer, age., , Third Generation (1964-1977):By the development of a, small chip consisting of the capacity of the 300 transistors., These Integrated Circuits (IC)s are popularly known as, Chips., , UNIVAC-1: It stands for Universal Automatic, computer and it was the First commercial computer, developed by United States In 1951. The machine was, 25 feet by 50 feet in length, contained 5,600 tubes, 18,000, crystal diodes, and 300 relays. It utilized serial circuitry,, 2.25 MHz bit rate, and had an internal storage capacity, 1,000 words or 12,000 characters., , A single IC has many transistors, registers and capacitors, built on a single thin slice of silicon. So it is quite obvious, that the size of the computer got further reduced. Some, of the computers developed during this period were IBM360, ICL-1900, IBM-370, and VAX-750. Higher level, language such as BASIC (Beginners All purpose, Symbolic Instruction Code) was developed during this, period., , The UNIVAC was used for general purpose computing, with large amounts of input and output. The UNIVAC, was also the first computer to come equipped with a, magnetic tape unit and was the first computer to use, buffer memory., Limitations of First Generation Computer, Followings are the major drawbacks of First generation, computers., , Computers of this generation were small in size, low cost,, large memory and processing speed is very high. Very, soon ICs were replaced by LSI (Large Scale Integration), which consisted about 100 components., An IC containing about 100 components is called LSI as, in (Fig 2)., Features, , • They used valves or vacuum tubes as their main, electronic component., , • They were large in size, slow in processing and had, less storage capacity., , • They consumed lots of electricity and produced lots, of heat., , • Their computing capabilities were limited., • They were not so accurate and reliable., • They used machine level language for programming., • They were very expensive., Second Generation (1955-1964): The second-generation computer used transistors for CPU components, and ferrite cores for main memory&magnetic disks, for secondary memory. They used high-level languages, such as FORTRAN (1956), ALGOL (1960) & COBOL, (1960 - 1961). Input Output (I/O)processor was included, to control I/O operations., Manufacturing cost was also very low. Thus the size of, the computer got reduced considerably., It is in the second generation that the concept of Central, Processing Unit (CPU), memory, programming language, and input and output units were developed. Some of the, second generation computers are IBM 1620, IBM, 1401,CDC 3600., 8, , • They used Integrated Circuit (IC) chips in place of the, transistors., , • Semi conductor memory devices were used., • The size was greatly reduced, the speed of processing, was high, and they were more accurate and reliable., , • Large Scale Integration (LSI) and Very Large Scale, Integration (VLSI) were also developed., , • The mini computers were introduced in this generation., • They used high level language for programming., Fourth Generation (1978 - present): An IC containing, about 100 components is called LSI (Large Scale, Integration) and the one, which has more than 1000 such, components, is called as VLSI (Very Large Scale, Integration)., It uses large scale Integrated Circuits(LSIC) built on a single, silicon chip called microprocessors. Due to the, development of microprocessor it is possible to place, computer's centralprocessing unit(CPU) on single chip., These computers are called microcomputers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Later very large scale Integrated Circuits(VLSIC) replaced, LSICs. Thus the computer which was occupying a very, large room in earlier days can now be placed on a table., The personal computer (PC) that you see in your school, is a Fourth Generation Computer Main memory used fast, semiconductors chips up to 4 M bits size. Some of the, Fourth generation computers are IBM PC, AppleMacintosh, etc., , Fig 3, , Hard disks were used as secondary memory. Keyboards,, dot matrix printers etc. were developed. Operating System, (OS)-such as MS-DOS, UNIX, Apple's Macintosh were, available. Object oriented language, C++ etc were, developed., Features, , • They used Microprocessor (VLSI) as their main, switching element., , • They are also called as micro computers or personal, computers., , • Their size varies from desktop to laptop or palmtop., • They have very high speed of processing; they are, 100% accurate, reliable, diligent and versatile., , • They have very large storage capacity., Fifth Generation (PRESENT AND FUTURE): 5th, generation computers use ULSI (Ultra-Large Scale, Integration) chips. Millions of transistors are placed in a, single IC in ULSI chips., 64 bit microprocessors have been developed during this, period.. Memory chips and flash memory up to 1 GB,, hard disks up to 600 GB & optical disks up to 50 GB have, been developed (fig. 3)., , CP110113, , CP110113, , Fifth generation computing devices, based on Artificial, Intelligence, are still in development, though there are some, applications, such as voice recognition, that are being used, today., Artificial Intelligence is the branch of computer science, concerned with making computers behave like humans., The term was coined in 1956 by John McCarthy at the, Massachusetts Institute of Technology. Artificial, intelligence includes:, , • Games Playing: Programming computers to play, games such as chess and checkers, , • Expert Systems: Programming computers to make, decisions in real-life situations (for example, some, expert systems help doctors diagnose diseases based, on symptoms), , • Natural Language: Programming computers to, understand natural human languages, , • Neural Networks: Systems that simulate intelligence, , by attempting to reproduce the types of physical, connections that occur in animal brains, , • Robotics: programming computers to see and hear, and react to other sensory stimuli, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 9
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Table - 1, GENERATION, , ELECTRONIC COMPONENT, , ADVANTAGES, , First, , Vaccum tube, , Helped in calculation, and computational work, , Second, , Transistor, , 1.Smaller size, 2.Less cost, 3.Better speed, 4.Low power consumption, and less heat generation, 5.Better storage capacity, 6.Better accuracy and, more reliability, , Third, , Integrated Circuits(IC), small & medium scale, , 1.Better in all aspects, 1.Initial problem withmanufaccompared to I & II, turers, 2.Used operating systems 2.No insight obtained into, and high level language, internal working, , Fourth, , VLSI or Microprocessor, , 1.Low cost, 2.Excellent speed and, reliability, 3.Computers close to man, , Fifth, (Knowledge, Information, Processing, Systems), , ULSI or Bio-Chips, , 1.Very cheap, , 1.Big size, 2.Very costly, 3.Slow speed, 4.Low accuracy, 5.Low storage, 6.High power requirements, 7.High heat generation, 8.High failure rate, 9.Used machine language, 10.No operating system, 1.Need air conditioning, 2.Constant maintenance, 3.No operating systems, 4.Later stage computers used, assembly languages, , 1.Less powerful than main, frame computers, , 1.New low level language, needed, , 2.super speeds, 3.Very high storage capacity, 4.Highly sophisticated OS, 5.posses intelligence and, decision making ability, , Classification of computers, Computers are classified according to the following criteria:, , • Principle of Operation, • Computing Power, Memory Capacity and cost, • Technological Development, • Principle of operation, , It is a computer that measures continuously changing, physical quantities such as current, temperature,, pressure etc. and converts them into quantities which, can be used as data for computation. As these computers, deal with continuously varying quantities they will give, only approximate results. Its output is usually displayed, on a meter or scale. Analog computer has low memory, and fewer functions. These are used for engineering and, scientific applications., , •, , Analog computer, , • Thermometer, , •, , Digital Computer, , • Speedometer, , •, , Hybrid Computer, , • Analog clock, , Analog Computer, 10, , DISADVANTAGES, , Digital Computer, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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A digital computer works with digital data. Digital computer, uses binary number system. Binary number system, consists of only two digits '0' and '1'. A digital computer, represents data in digital signals. A '0' represents OFF, and a '1' represents ON. Digital computer performs, arithmetic and logical operations on data. It gives output, in digital form., , store results. They have large Memory (that is data storing, capacity). Today most of the computers used in offices, and homes are Digital computers., , • Special purpose computers, , Digital computers are very fast. These computers can, , • General purpose computers, , The digital computers are further divided into the, following two groups:, , Table 2, Analog Computers, , Digital Computers, , 1. Analog Computers Work on continuous values., 2 Analog Computers have low memory., 3 Analog computers have Slow speed., , Digital computers Work on discrete values., Digital computers have a very large memory, Digital computers have fast speed., , 4 Analog computers are less reliable., , Digital computers are more reliable., , 5 Analog computers used in engineering, , Digital computers are used in all fields of life., science and medical fields., , 6 Analog computers are used to calculate /, , Digital computers are used to calculate, , measure analog quantities like speed and, , mathematical and logical operations. It can, , temperature., , solve addition, subtraction, division,, multiplication and other mathematical and, statistical operations., , 7 Analog computers provide less accurate results., , Digital computers provide 100% accurate results., , 8 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 9 Normally Analog Computers are specific purpose, , Digital Computers are general purpose, , 10 Examples of Analog computers are: thermometer,, , Examples of digital computers are:, , analog clock, speedometer etc., , Personal Computer, laptops, smart phones etc., , Special Purpose Computers, It is a computer designed to solve specific type of, problem. The computers used in ships and aircrafts, etc., General Purpose computers, It is a computer designed to solve a wide variety of, problems, A General purpose Computer can store, different programs and process them., The differences between analog and digital computers, are listed in table 2, Hybrid Computer (Fig. 4), A hybrid computer is a combination of both analog and, digital computer. Hybrid computer can handle both, analog and digital data. A hybrid computer combines the, best characteristics of both the analog and digital, computer. It can accept data in both analog and digital, form., Applications, Hybrid computer devices are used in hospitals that may, calculate patient's heart function, temperature and blood, pressure etc. This calculation may be converted into, , numbers and shown in digital form. For example, The Vital, Signs Monitoring unit also called (VSM) in short. It has, Blood Pressure monitor, ECG monitor, respiratory monitor,, and is also used for monitoring anesthesia., , • Hybrid computers are also used in spaceships and, missile system., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 11
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•, , Hybrid Computer Machines are generally used in, scientific applications, , •, , Hybrid computers are used for controlling industrial, processes., , Computers are classified on the basis of computing, power, memory capacity and cost., - Microcomputer or Personal Computer., - Mini Computer., - Mainframe Computer., - Super Computer., Micro Computers, Micro computer is also called personal computer. It was, introduced in 1970. Examples of personal computers are, PC and Apple Macintosh. The major types of personal, computers are desktop computer and portable computer., Desktop Computer, , Fig 6, , CP110116B, , These computers can easily fit on a table or desktop,, hence the name. These computers come in two models, or casings. In Desktop model, the system unit is placed, on the desktop or table. Monitor is placed on the system, unit. In Tower model, both monitor and system unit are, placed on the table as in (Fig 5)., , Palmtops have no keyboard but the screen serves both, as an input and output device. It easily fits in the hand of, the user., Uses of Micro Computer, The PC is the most common type of computer used in, the office. It is now widely used in many homes. These, are also used for business and engineering application., , Portable computer, Portable is a personal computer that can be carried from, one place to other easily. Notebook computer and, handheld computer (smart phone) are examples of, portable computers. Notebook computer is also called, laptop computer. Laptop computers are very small in, size and can be placed easily on lap., , Mini Computer, , Lap top computer or notebook computer, , Minicomputer can serve up to 4000 connected users, simultaneously. It is normally accessed by users via, personal computer or terminal. A device with a monitor, and keyboard is called terminal. It is also known as dumb, terminal. It has no processing power and cannot work as, stand-alone computer. Some of the minicomputers, models are VAX-8800, AS400, , The laptop computer or notebook computer will be as, shown in fig 6a and fig 6b.It is also called as tower model, computer., Palmtop Computer/Digital Diary /Notebook /PDAs:, A handheld computer (like smart phone) is also portable., Hand held computer is known as palmtop computer., 12, , Mini computers were introduced in the 1960s., Minicomputer is larger and more powerful computer than, personal computer. It can execute five million instructions, per second. It generally consists of two or more, processors., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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Uses of Mini Computer, Mini computers are often used by small and medium-sized, companies to provide centralized store of information., Mainframe Computer, Mainframe computers were introduced in 1975. A, mainframe computer is a very large computer in size. It is, processors. It is designed to perform multiple tasks for, multiple users at the same time. Mainframe computers, can serve up to 50,000 users at the same time., , programs concurrently. The modern super computer, consists of thousands of microprocessors. Super computer, uses high-speed facilities such as satellite for online, processing., Sum of the super computers models are CRAY-XP, ETA10, Param and Deep Blue ., Advantages of computers, •, , A computer has a very high processing speed with high, reliability., , •, , Large volume of information can be stored in the, memory any particular data/program can be retrieved, immediately., , •, , Solution to a complicated problem is possible at a very, high speed., , •, , Processing of large volume of data saves a lot of clerical, work which reduces the processing cost., , Mainframe computers are used primarily by corporate, and governmental organizations for critical applications,, bulk data processing such as senses, industry and, consumer statistics, and transaction processing., , •, , Computers perform operations efficiently at, environments where presence of human being is not, possible such as furnace, poisonous atmosphere,, vacuum, unmanned satellite, etc., , Super computer, , Limitation of computers, , Super computers were introduced in 1980s. Super, computer is the fastest computer. Super computer is the, biggest in size and the most expensive in price than any, other computers., , •, , High initial cost., , •, , Input information has to be prepared in the form of, statements called program which requires a, considerable amount of knowledge., , •, , usage of computers will be economical only when there, is clerical data processing for large volume of data and, are repetitive in nature, , •, , It is a merely a machine it cannot correct errors on its, own., , The users access a mainframe computer through, terminal or personal computer. A typical mainframe, computer can execute 16 million instructions per second., Some of the main computers models are, •, •, , NEC 610, DEC 10, , Uses of Mainframe Computer, , It is the most sophisticated, complex and advanced, computer. It has a very large storage capacity. It can, process trillions of instructions in one second. Super, Computer is the fastest and most powerful computer of, a time. Supercomputers are very expensive., Supercomputers are used for highly calculation-intensive, tasks. Super computers are also used for specialized, applications that require immense amounts of, mathematical calculations., Applications of Super Computer, •, , Weather forecasting,, , •, , Animated graphics like in Hollywood movies,, , •, , Fluid dynamic calculations, , •, , Nuclear energy research, , •, , Space science, , •, , Weapon and missile design, , •, , Petroleum exploration, and etc., , Today, supercomputers are produced by traditional, companies such as Cray, IBM and Hewlett- Packard., Since October 2010, the Tianhe-1A supercomputer has, been the fastest in the world; it is located inChina., The main difference between a supercomputer and a, mainframe is that a supercomputer channels all its power, into executing a single program as fast as possible,, whereas a mainframe uses its power to execute many, , Functions of Computers, All computers are made up of following basic units as, shown in fig (7). They are as follows:1 Input Unit, 2 Central processing Unit (CPU), a) Arithmetic Logic Unit(ALU), b) Control Unit (CU), 3 Memory, 4 Output Unit, Input Unit, Computers need to receive data and instruction in order, to solve any problem. Therefore we need to input the, data and instructions into the computers. The input unit, consists of one or more input devices. Keyboard is the, one of the most commonly used input device. Some of, the input devices are listed in table 1., Input devices perform the following functions., •, , Accept the data and instructions from the outside world., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 13
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•, , Convert it to a form that the computer can understand., , •, , Supply the converted data to the computer system for, further processing., , Central Processing Unit (CPU) (Fig. 8), The central processing unit (CPU) is the electronic brain, , use in a computer or other digital electronic device., There are two types of memory in computer., •, •, , Primary Memory, Secondary Memory, , Output Unit, Output unit receive the informations from the processing, unit and provide the results in human readeable form., Output Devices, The some of the output devices are, • Monitor, • Printer, • Plotter, • Speaker, Applications of computers, , of the computer as in fig-8. The CPU in a personal computer, is usually a single chip. It organizes and carries out, instructions that come from either the user or from the, software. The processor is made up of many components., CPU performs the following functions:, •, •, •, , It performs all calculations., It takes all decisions., It controls all units of the computer., , Two typical components of a CPU are the following:, The arithmetic logic unit (ALU), which performs arithmetic, and logical operations., The control unit (CU), which extracts instructions from, memory and decodes and executes them, calling on the, ALU when necessary., Memory, Memory refers to the physical device used to store the, program or data on the temporary or permanent basis for, , 14, , Science: Scientists have been using computers to, develop theories and to analyse and test the data. The, high speed and accuracy of the computer allow different, scientific analyses to be carried out. They can be used, to generate detailed studies of how earthquakes affect, buildings or pollution affects weather pattern. Satellitebased applications have not been possible without the, use of computers. Moreover, it would not be possible to, get the information of the solar system and the cosmos, without computers., Education: Computers have also revolutionized the, whole process of education. Currently, the classrooms,, libraries and museums are efficiently utilizing computers, to make the education much more interesting. Unlike, recorded television shows, computer-aided education, (CAE) and computer-based training (CBT) packages are, making learning much more interactive., Medicine and Health Care: There has been an, increasing use of computers in the field of medicine., Now, doctors are using computers right from diagnosing, the illness to monitoring a patient's status during complex, surgery. By using automated imaging techniques, doctors, are able to look inside a person's body and can study, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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CP110117t1, , Fig 9, , each organ in detail (e.g. CT scans or MRI scans), which, was not possible few years ago. There are several, examples of special-purpose computers that can operate, within the human body such as cochlear implant, a, special kind of hearing aid that makes it possible for, deaf people to hear., Engineering/Architecture/Manufacturing: The, architects and engineers are extensively using computers, in designing and drawings. Computers can create objects, , that can be viewed from all the three dimensions. By using, techniques like virtual reality, architects can explore houses, that have been designed but not built. The manufacturing, factories are using computerized robotic arms to perform, hazardous jobs. Besides, computer-aided manufacturing, (CAM) can be used in designing the product, ordering the, parts and planning production. Thus, computers help in, coordinating the entire manufacturing process., , IIT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished, , 15
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Entertainment: Computers are finding greater use in, entertainment industry. They are used to control the, images and sounds. The special effects, which, mesmerize the audience, would not have been possible, without the computers. In addition, computerized, animation and colourful graphics have modernized the, film industry., , Banking: Computers are extensively used in the field of, banking and finance. People can use the ATM (automated, teller machine) services 24 hours a day to deposit and, withdraw cash. When different branches of the bank are, connected through computer networks, the inter branch, transactions such as cheque and draft can be performed, without any delay., , Communication: E-mail or electronic mail is one of the, communication media in which computer is used. Through, e-mail, messages and reports are passed from one person, to one or more persons with the aid of computer and, telephone line. The advantage of this service is that while, transferring the messages it saves time, avoids wastage, of paper and so on. Moreover, the person who is receiving, the messages can read the messages whenever he is, free and can save it, reply it, forward it or delete it from the, computer., , Railway Reservation System, , Business Application: This is one of the important uses, of the computer. Initially, computers were used for batchprocessing jobs, where one does not require the, immediate response from the computer. Currently,, computers are mainly used for real-time applications (like, at the sales counter) that require immediate response, from the computer. There are various concerns where, computers are used such as in business forecasting, to, prepare pay bills and personal records, in banking, operations and data storage, in various types of life, insurance business and as an aid to management., Businesses are also using the networking of computers,, where a number of computers are connected together, to share the data and the information. Use of e-mail and, the Internet has changed the ways of doing business., Publishing: Computers have created a field known as, desktop publishing (DTP). In DTP, with the help of, computer and a laser printer one can perform the, publishing job all by oneself. Many of the tasks requiring, long manual hours such as making table of contents and, index can be automatically performed using the, computers and DTP software., , 16, , Using this system, the user can perform following, operations through online. (web site: www.irctc.co.in), •, •, •, •, , search the train and its timings, check seats and birth availability, booking and cancelling tickets, status of PNR (Passenger Name Record), , Telephone / Electricity Board Billing:, The users can do the following operations through online, by using this system. (Web site: portal.bsnl.in - BSNL), • Register the telephone / electricity board number, • Check and pay the bill amount, • Register the complaints, E-Governance, E-Governance implies technology driven governance., E-Governance is the application of Information and, Communication Technology (ICT) for delivering, government services, exchange of information, communication transactions, integration of various standalone systems and services between Government-toCitizens, (G2C),, Government-toBusiness(G2B),Government-to-Government( G2G) as, well as back office processes and interactions within the, entire government frame work., E-Governance covers all the sectors with a view to, providing hassle free, transparent and efficient service, to the common man (both in urban and rural areas)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.05, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise1.2.06, COPA - Introduction to computer components, Introduction to CPU architecture and motherboard, Objectives: At the end of this lesson you shall be able to, • state what is hardware and test the internal and external hardware, • brief the listed hardware, • state what is partitions and their types, • explain the booting and its procedures., Computer Hardware, The physical units of a computer are called as the, hardware of a computer., Internal hardware examples, •, , Blu-Ray, CD-ROM, and DVD, , •, , CPU, , •, , Hard drive, , •, , Motherboard, , •, , RAM, , •, , Sound card, , •, , Video card, , •, , SMPS, , External hardware examples, •, , Flat-panel, Monitor, and LCD, , •, , Keyboard, , •, , Mouse, , •, , Printer, , •, , Scanner, , CPU & ALU, Central Processing Unit (CPU) is the heart of the, Computer. It is the hardware,that carries out the, instructions of a computer program by performing the, basic arithmetical, logical, and input/output operations, of the system., , Most connectors are separated, permitting the cable to, be plugged in only in the correct direction. The keyboard, and mouse use "PS2" (Personal System 2) connectors., The PS2 connectors are color-coded. The purple, connector is for the keyboard. The green connector is, for the mouse., •, , PS/2 Ports: Standard keyboards and mouse often, connect to the computer via the PS/2 ports. To plug, in a keyboard or mouse cable, first match the cable, to the connector. Then push the cable into the, connector. Be sure not to force the connector because, you will end up bending the pins, , •, , Serial & Parallel Ports: The serial port and parallel, port allow connections to printers and other external, devices. To transfer a byte through a serial port, eight, bits are queued and sent bit by bit. However, in a, parallel port, all the eight bits are transferred, simultaneously, , •, , The parallel port, serial port, and video port all use "D", type connectors (DB-25M, DB-9M and DB-15F, respectively). These are called D connectors because, of their shape, which permits the cables to be plugged, in only one way., , CPU Ports and Connectors, A port is a connector at the back of a Computer cabinet, where you plug in an external device such as a printer,, keyboard, scanner, modem etc. This allows instructions, and data to flow between the computer and the device., The computer ports are also commonly referred to as, the Input/output ports (I/O ports). These ports can be, either serial or parallel. Fig 1 shows the commonly, available ports on a personal computer., , Copyright @ NIMI Not to be Republished, , 17
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USB (Universal serial bus) Ports, , The System Unit and Its Components, , Devices like digital cameras, scanners and printers often, connect to the motherboard via the USB ports. A USB, connector's distinctive rectangular shape makes it easily, recognizable., , The system unit is a box-like unit filled with a number of, useful components, each performing a discrete function., These components work together to accomplish the main, function of the computer, viz. accept and process input, and deliver output. This section will elaborate on these, components one by one. Fig 3 shows the various, components of the system unit., , USB has a number of features that makes it particularly, popular on PCs. First, USB devices are hot swappable., You can insert or remove them without restarting your, system, LAN(Local Area Network) Port: The LAN port is used, to connect the PC to a local network or to high speed, Internet services., , Fig 3, , VGA (Video Graphics Array) Ports: The VGA port, provides access to integrated video., Audio ports: It provides access to integrated audio., The audio jacks are the most confusing connectors on, the back panel. Although the jacks are sometimes colorcoded, the devices that plug into them rarely., CPU front Panel shown Fig 2., , CP11011B, , Fig 2, , Power Supply, The power supply connects to nearly every device in the, PC to provide power. It is located at the rear of the case., The system unit draws power from the AC mains through, a power protection device., , It may contain the following parts., , • Power On/Off Switch, • Power Indicator, • CD/DVD Drive, • CD/DVD Drive Open/Close Button, • CD/DVD Drive indicator, • Floppy Disk Drive, • Floppy Disk Drive Indicator, • USB Ports, • Audio and Mic connectors, Design of CPU Cabinets may vary based on, the manufacturer., , 18, , This power is not directly supplied to the internal, components. Instead, one of the components, called the, internal power supply, converts the AC input into DC, output of 5 and 12 volts. Normally, the internal power, supply is referred to as Switched Mode Power Supply, (SMPS)., The SMPS provides cable connectors to supply the, required voltage to the other internal components like, the floppy drives, the hard disk drive, the motherboard, and external device such as the keyboard. The ON/OFF, switch of the system unit is actually a part of the SMPS., Fan, The SMPS has a small fan, called the exhaust fan,, attached to SMPS(Fig. 4). This fan rotates as long as, the computer is switched on. Its function is to cool the, SMPS unit., Drive Bays: The 5.25" and 3.5" drive bays house the, many kinds of storage devices a computer might contain., Expansion Slots: An expansion slot is a slot located, inside a computer mother board that allow additional, peripharals to be connected to it., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Power Port: Power is delivered to drives via cables that, plug into the power port on the drives., , Fig 4, , Peripheral cards slot, The peripheral cards are the spare expansion slots, available on the mother board on which peripheral cards, can be inserted., , CP11011C, , The following are the peripheral cards, , Memory Slot, , •, , Sound card, , •, , Video card, , •, , Modam, , •, , Wireless network, , Fig. 7 shows the peripheral card, designed with a PCI, (Peripheral component interconnect) connector., Fig 7, , Memory Slot is used to insert a Random Access, Memory(RAM) shown in fig 5, , Storage Drivers, Storage drivers such as hard drives, optical drives and, floppy drives all connect to the motherboard via cables, and is mounted inside the computer., IDE & SATA Cables: Fig 6 shows two hard disk drives, that connect in different ways to the motherboard. One, uses the older IDE cable connection while the other uses, SATA(Serial Advanced Technology Attachment) cable, which provides for faster hard drive access., , CP11011F, , CP11011D, , Fig 5, , Motherboard, The motherboard is a printed circuit that is the foundation, of a computer and allows the CPU, RAM, and all other, computer hardware components to function with each, other as on fig 8., Fig 8, , CP11011G, , Fig 6, , CP11011E, , "www. dget.gov.in", , The motherboard is the primary component of the entire, system. A mother board is a large board containing a, number of tiny electronic circuits and other components, are visible. All peripheral devices are connected to the, motherboard. The components of the motherboard are:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 19
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This means you can upgrade to a newer version of DOS, without changing the BIOS. PC BIOS that can handle, Plug-and-Play (PnP)devices are known as PnPBIOS,, These BIOS are always implemented with flash memory, rather than ROM., , •, , Keyboard / mouse port, , •, , Parallel and Serial port, , •, , Processor Socket, , •, , AGP Slot, , CMOS Battery, , •, , PCI Slots, , •, , ISA Slot, , •, , CMOS Battery, , CMOS (Complementary Metal-Oxide-Semiconductor) is, the term usually used to describe the small amount of, memory on a computer motherboard that stores the BIOS, settings., , •, , Data Card Connector, , •, , Memory Slots, , •, , Floppy Port, , •, , Fan Header, , •, , Main Power Connector, , Most CMOS batteries will last the lifetime of a, motherboard (up to 10 years in most cases) but will, sometimes need to be replaced. Incorrect or slow system, date and time and loss of BIOS settings are major signs, of a dead or dying CMOS battery., ISA slot: (Industry Standard Architecture) It is the, standard architecture of the Expansion bus. Motherboard, may contain some slots to connect ISA compatible cards., , Floppy Port :The floppy drive connects to the computer, via a 34-pin ribbon cable, which in turn connects to the, motherboard. A floppy controller is one that is used to, control the floppy drive., RAM slots: Random-Access Memory (RAM) stores, programs and data currently being used by the CPU., RAM is measured in units called bytes. RAM has been, packaged in many different ways, •, , SIMM-Single inline memory module -32 or 72 Pin, , •, , DIMM- Dual Inline Memory module -168 pin., , In most of the PC's uses of the DIMM module, ROM BIOS Chip: This means Read Only Memory Basic, Input-Output System., The built-in software that determines what a computer, can do without accessing programs from a disk. On PCs,, the BIOS contains all the code required to control the, keyboard,, display, screen,, disk, drives,, serialcommunications, and a number of miscellaneous, functions., The BIOS is typically placed in a ROM chip that comes, with the computer (it is often called a ROM BIOS). This, ensures that the BIOS will always be available and will, not be damaged by disk failures., It also makes it possible for a computer to boot itself., Because RAM is faster than ROM, though, many, computer manufacturers design systems so that the, BIOS is copied from ROM to RAM each time the, computer is booted. This is known asshadowing., Many modern PCs have flash BIOS, which means that, the BIOS have been recorded on a flash memory chip,, which can be updated if necessary. The PC BIOS is fairly, standardized, so all PCs are similar at this level (although, there are different BIOS versions). Additional DOS, functions are usually added through software modules., 20, , PCI slot : Intel introduced the Peripheral Component, Interconnect bus protocol. The PCI bus is used to, connect I/O devices to the main logic of the computer., PCI bus has replaced the ISA bus. PC motherboards, have one PCI slot but generally more than one., The PCI bus architecture is a processor-independent bus, specification that allows peripherals to access system, memory directly without using the CPU., AGP slot: The Accelerates Graphics Port (AGP) is a, high-speed point-to-point channel for attaching a video, card to a computer's motherboard., Power supply plug in, The Power supply, as its name implies, provides the, necessary electrical power to make the PC (Personal, Computer) operate. The power supply takes standard, 110-V AC power and converts into +/-12-Volt, +/-5-Volt,, and 3.3-Volt DC power. The power supply connector has, 20-pins, and the connector can go in only one direction., Hard Disk and Partitions, Partitioning is a process of dividing the Hard disk into, several chunks, and uses any one of the portion or, partition to install OS or use two or more partitions to, install multiple OS.., But it can always have one partition, and use up the, entire Hard disk space to install a single OS, but this will, become data management nightmare for users of large, Hard disks., Now, because of the structure of the Master Boot Record, (MBR), has only four partitions, and these four partitions, are called Primary Partitions., Extended Partition is not a usable partition by itself,, but it's like a "container" and it is used to hold, LogicalDrives!That is this Extended Partition can be, subdivided into multiple logical partitions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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In order to boot into a Partition, it must be designated, as bootable partition or Active Partition. Active Partition, is that partition which is flagged as bootable or which, contains OS, this is generally a Primary Partition., , Fig 9, , Types of Partitions:, •, , Master, , •, , Partition, , •, , Extended and, , •, , Logical Extended, , Master Boot Record (MBR): MBR is a small 512 bytes, partition which is at the first physical sector of the hard, disk. The location is denoted as CHS 0,0,1 meaning 0th, Cylinder, 0th Head and 1st Sector., MBR contains a small program known as bootstrap, program which is responsible for booting into any OS., MBR also contains a table known as Partition Table., This Partition Table is a table which lists the available, Primary Partitions in the hard disk. Partition table, considers whole Extended Partition as one Primary, partition and lists it in the table!, So a Partition table can have two possible entries:•, , Up to 4 Primary Partitions., , •, , Up to 3 Primary Partitions and 1 Extended, Partition.(Total not exceeding 4) ., , Partition Boot Sector (PBR): This is the logical first, sector, that is sector at the start of a Primary Partition., This is also 512 byte area, which contains some programs, to initialize or run OS files. All Primary Partitions have, its own PBRs., Extended Boot Sector (EBR): This is the logical first, sector, that is the sector at the start of the Extended, Partition. This EBR contains a Partition Table, which lists, the available Logical Partitions inside Extended Partition., That is it contains the Starting addresses of each Logical, Partitions., Logical Extended Boot Sector (LEBR): This is the, logical first sector residing at the start of each Logical, Partition. This is similar to PBR for Primary Partitions., Booting, Booting is a process of loading the operating system, (OS) and checking all the system software and hardware, those are installed in the computer., Booting procedure of Windows operating system, Functions of BIOS, The first process starts, when the computer switched on, Basic Input Output System (BIOS) perform two functions,, to conduct POST and read MBR (Fig 9)., , POST - POST stands for Power OnSelf Test. POST, checks all the hardware devices connected to a computer, like RAM, hard disk etc and make sure that the system, can run smoothly with those hardware devices. If the, POST is a failure the system halts with a beep sound., Now BIOS checks the boot priority. We can set the, boot priority as CD drive, hard disk or floppy drive., MBR - The next duty of BIOS is to read the MBR. MBR, stands for Master Boot Record and it's the first sector on, a hard disk. MBR contains the partition table and boot, loader., Functions of Boot loader, Now BIOS has passed the control to boot loader and, boot loader is a small program which loads kernel to, computers memory. Actually there are two stages of boot, loaders, stage 1 boot loader and stage 2 boot loader., The stage 1 boot loaderis a link to the stage 2 boot loader., The stage 2 boot loader resides in the boot partition and, it loads the kernel to memory., Boot files and functions, There are three boot files in a Windows operating system, and they are NTLDR, NTDETECT.COM and Boot.ini., The boot files are found in the active partition of hard, disk and its normally C drive in a Windows machine., NTLDR - NTLDR stands for NT Loader and it's the, second stage boot loader. The path of NTLDR is, C:\Windows\i386\NTLDR., Boot.ini - Boot.ini contains the configuration files of, NTLDR. When the operating system is loaded we cannot, pass any arguments to kernel, so those arguments are, passed through boot.ini. You can edit boot.ini by opening, through notepad. The path of Boot.ini is C:\boot.ini., NTDETECT.COM, This file detects hardware's and passes information to, NTLDR. Using the collected information the NTLDR, creates a hardware key and this key is used to detect, hardware's., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 21
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A new hardware key is generated after each reboot of the, operating system and that's why system asks to reboot, after installation of a new hardware. The hardware keys, created by NTLDR can be found in Windows registry at, HKEY_LOCAL_MACHINE ' HARDWARES., Kernel and its functions, After executing the functions of boot files the control is, passed to Kernel. ntoskrnal.exe is the kernel file in a, Windows machine and its path is C:\Windows\system, 32\ntoskrnal.exe., Kernel acts as a layer between software and hardware., The library file hal.dll (C;\Windows\system32\hal.dll) helps, Kernel to interact with hardware's. HAL stands for Hardware, Abstraction Layer and this hal.dll file is machine specific., Now the drivers for hardware's are loaded from the file, C:\Windows\system32\config\system and the Kernel is, loaded to primary memory., Services and log in procedure, When kernel is loaded in the primary memory, services, for each process is started and the registry entry for those, services can be found at HKEY_LOCAL_MACHINE System - Current control set - Services., Winlogon.exe (C:\Windows\system32\winlogon.exe) is, the last service started during this process., Winlogon.exe starts the log in procedures of windows, machine. It first calls the library file msgina.dll, (C:\Windows\system32\msgina.dll)., MSGINA stands for Microsoft Graphics Identification and, Authentication and it provides the log in window. Now, msginal.dll passes the control to LSA (Local Security, Authority), it verifies the username and password from, the SAM file. SAM (Security Accounts Manager) contains, the information about all users created in a Windows, operating system., Now the booting procedure is over and it has reached, the desktop of Windows operating system., Voltage: Every electric charge is capable of doing work, by moving another charge either by attraction or by, repulsion. This ability of a charge to do work represents, its potential. Voltage is generated by the separation of, charges. Voltage or electric potential is the state of, separated charges striving to neutralize each other. The, unit of electric potential is volt. Potential difference is, necessary to cause flow of electric current., Methods of voltage generation: Voltage can be generated, by several ways. Some methods of generating coltage, are:, , • Voltage from chemical reactions, Measuring voltage: Voltage exists between any two, points with different levels of charge. Voltage between, any two points can be measured using an instrument, called VOLTMETER. Meters used to measure current is, called Ammeter. There are meters which can be used to, measure voltage and current and a few other electrical, parameters like resistance. Such meters are called, MULTIMETERS., Types of voltage: As discussed in above paragraphs there, are several sources by which voltage can be developed., Depending upon the voltage source, the voltage developed, can be,, Direct voltage: It is of constant magnitude. It remains at, the same amplitude from the moment it is switched ON, till the moment it is switched - OFF., Alternating voltage: In this type, voltage source changes, its polarity regularly and therefore the direction of, developed voltage., A mixed voltage is a combination of direct voltage and, alternating voltage. The level of voltage is not constant., It varies around a mean value., Electric Current: Electric current is produced when, electric charges move in a definite direction. This, movement is not only of negative charges but also of, positive charges. The strength of electric current is the, quantity of charge which flows across a given cross, section of a conductor every second. The unit of current, strength is Ampere., Current strength = Quantity of charge/time, Measuring current: Electric current is the flow of charge,, in a conductor. So, to measure current must pass through, the measuring device. The current measuring instrument, is called the ammeter of the current meter. There are, different types of ammeters used for measuring different, quantities of current., Types of current: Voltage causes electrical current to, flow. If the cause of current flow is a direct voltage source,, then the current caused by its called direct current (d.c)., On the otherhand, then the current caused is referred as, the alternating current. If a mixed voltage AC and DC) is, applied to an electrical circuit, a mixed current (AC and, DC) will flow through the circuit., Types of power supply: Irrespective of how the, electricity is generated, electricity can be classified into, two types., •, , Alternating current, generally known as AC supply., Direct current, generally known as DC supply., , •, , Voltage from friction, , •, , •, , Voltage from moving magnets or coils, , •, , Voltage from pressure or tension in crystals, , •, , Voltage from heat, , AC supply: The term alternating current supply is given to, a supply source that makes current to flow through a circuit, which reverses or alternates its direction periodically., , •, , Voltage from light, , 22, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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Advantages of AC supply, •, , Reduced transmission loss over long distances., , •, , Voltage levels can be changed using simple devices, called transformers., , •, , Reduced severity of electrical shock., , •, , Generating equipments are simple and cheaper, , •, , Can be easily converted to DC supply., , DC supply: The term direct current supply is given to a, supply source that makes current to flow through a circuit, in one direction only. Example of DC supply is batteries., Some types of generators are also designed to give d.c., supply. Such generators are called DC generators., Low tension (LT) voltage: The domestic voltage of 240, volts AC (generated and supplied by hydro or Thermal, or Nuclear generating stations) is called the low tension, (LT) voltage. LT lines enters residential buildings from, electricity poles called as service connection. This 240, volts is used to light up the lamps, run fans etc in homes., To connect electrical appliances at home, 240V AC is, available in either two-pin or three - pin sockets. This LT, voltage of 240 volts, 50Hz is also used to supply electrical, and electronic gadgets such as Iron box, washing, machine, personal computer etc., Phase, Neutral and Earth points of LT supply: The, domestic AC mains supply of 240V, 50Hz, is available, at consumers residence either in a 2-pin outlet (Phase Neutral) or in a 3-pin outlet (phase -Neutral and Ground)., These are commercially referred to as 2/3 pin sockets., These sockets look similar to the ones shown in Fig. 10., , recorders etc., Hence such gadgets does not need earth, pin/point on the socket., Iron box, washing machines, drill guns, Desk top computer, invariably need sockets with provision of earth pin, because, of the possibility of shock while using these equipments., Hence such equipments/gadgets make use of AC mains, socket with earth., Connection of 3-pin AC mains socket: Fig 11 shows, how the main supply is connected to the socket., Fig11, , Note that in a AC outlet be it a 2-pin or a 3-pin phase is, always connected to the socket through a switch. This, prevents the users from getting electrical shock when the, switch is put in off position., The standard voltage appearing across the 3-pin terminals, is shown in Fig12, Fig 12, , Fig 10, , Phase: The line or phase point in a socket, can be termed, as the point from where the electricity starts flowing into a, closed circuit., Neutral: The neutral point in the socket, can be termed, as the point which receives electricity from the closed, circuit., Earth / Ground: The ground (some call it Earth) point in, an electrical socket provides the easiest path for the, leakage current and other minor electrical defect currents, of appliances., Two pin mains sockets are used to supply main to such, equipments or apparatus or gadgets generally having its, cabinets/chassis made of plastic such as radio, tape, , The voltages across the pins of the socket can be measured, using an AC voltmeter or a multimeter in AC volts range., As a quick test to find out whether or not a socket is, delivering the AC supply as required, a simple instrument, called line tester which looks similar to a small screw, driver can be used. This instrument will have a small, bulb in it which glows if it is touched to the phase pin in, the socket. Ask your instructor to demonstrate the use of, such line tester to check a AC mains socket., Most Desk top computers need AC mains supply for its, operation. Although the mains supply available in the 3pin socket shown above can be used, mostly this AC, supply is cleaned fro spikes before connecting to, computers. The device used for cleaning the spikes in the, mains AC supply are called Spike Arrestors or Spike, busters., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished, , 23
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Computers are used with spike busters because, AC spikes, are likely to damage the costly computers. In addition to, spike busters, most computers use other power safety, devices called the voltage stabilizers and uninterrupted, power supplies., , 24, , Power supply in computers: Power supply unit in, computers are firmly fitted on the processing unit cabinet, using torx screws. Generally there will be four such screws, fitted to fix the power supply init in the cabinet., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.2.06, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise : 1.3.07 - 1.3.11, COPA - Windows Operating System, Windows Operating System, Objective: At the end of this exercise you shall be able to, • list out the windows versions and features, Windows versions and its features, Microsoft Windows has seen nine major versions since, its first release in 1985. Over 29 years later, Windows, looks very different but somehow familiar with elements, that have survived the test of time, increases in, computing power and - most recently - a shift from the, keyboard and mouse to the touchscreen., Here's a brief look at the history of Windows, from its, birth at the hands of Bill Gates with Windows 1 to the, latest arrival under new Microsoft chief executive, SatyaNadella., , Apple's Macintosh and the Commodore Amiga graphical, user interfaces, coming pre-installed on computers from, PC-compatible manufacturers including Zenith Data, Systems., Windows 3 introduced the ability to run MS-DOS, programmes in windows, which brought multitasking to, legacy programmes, and supported 256 colours bringing, a more modern, colourful look to the interface., More important - at least to the sum total of human time, wasted - it introduced the card-moving timesink (and, mouse use trainer) Solitaire., , Windows 1, , Windows 3.1, , The first version of Windows, , Windows 3.1 with Minesweeper., , This is where it all started for Windows. The original, Windows 1 was released in November 1985 and was, Microsoft's first true attempt at a graphical user interface, in 16-bit., , Windows 1 and 2 both had point release updates, but, Windows 3.1 released in 1992 is notable because it, introduced TrueType fonts making Windows a viable, publishing platform for the first time., , Development was spearheaded by Microsoft founder Bill, Gates and ran on top of MS-DOS, which relied on, command-line input., , Minesweeper also made its first appearance. Windows, 3.1 required 1MB of RAM to run and allowed supported, MS-DOS programs to be controlled with a mouse for, the first time. Windows 3.1 was also the first Windows, to be distributed on a CD-ROM, although once installed, on a hard drive it only took up 10 to 15MB (a CD can, typically store up to 700MB)., , It was notable because it relied heavily on use of a mouse, before the mouse was a common computer input device., To help users become familiar with this odd input system,, Microsoft included a game, Reversi (visible in the, screenshot) that relied on mouse control, not the, keyboard, to get people used to moving the mouse, around and clicking onscreen elements., Windows 2, Windows 2 with overlapping windows., Two years after the release of Windows 1, Microsoft's, Windows 2 replaced it in December 1987. The big, innovation for Windows 2 was that windows could overlap, each other, and it also introduced the ability to minimise, or maximise windows instead of "iconising" or "zooming"., The control panel, where various system settings and, configuration options were collected together in one, place, was introduced in Windows 2 and survives to this, day., Microsoft Word and Excel also made their first, appearances running on Windows 2., Windows 3, Windows 3.0 got colourful., The first Windows that required a hard drive launched in, 1990. Windows 3 was the first version to see more, widespread success and be considered a challenger to, , Windows 95, Windows 95: oh hello Start menu., As the name implies, Windows 95 arrived in August 1995, and with it brought the first ever Start button and Start., It also introduced the concept of "plug and play" - connect, a peripheral and the operating system finds the, appropriate drivers for it and makes it work. That was, the idea; it didn't always work in practice., Windows 95 also introduced a 32-bit environment, the, task bar and focused on multitasking. MS-DOS still, played an important role for Windows 95, which required, it to run some programmes and elements., Internet Explorer also made its debut on Windows 95, but, was not installed by default requiring the Windows 95 Plus!, pack. Later revisions of Windows 95 included IE by default,, as Netscape Navigator and NCSA Mosaic were popular at, the time., Windows 98, Windows 98, the last great DOS-based Windows., Released in June 1998, Windows 98 built on Windows, 95 and brought with it IE 4, Outlook Express, Windows, , Copyright @ NIMI Not to be Republished, , 25
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Address Book, Microsoft Chat and NetShow Player, which, was replaced by Windows Media Player 6.2 in Windows, 98 Second Edition in 1999., , CD burning, autoplay from CDs and other media, plus, various automated update and recovery tools, that unlike, Windows ME actually worked., , Windows 98 introduced the back and forward navigation, buttons and the address bar in Windows Explorer, among, other things. One of the biggest changes was the, introduction of the Windows Driver Model for computer, components and accessories - one driver to support all, future versions of Windows., , Windows XP was the longest running Microsoft operating, system, seeing three major updates and support up until, April 2014 - 13 years from its original release date., Windows XP was still used on an estimated 430m PCs, when it was discontinued., , USB support was much improved in Windows 98 and, led to its widespread adoption, including USB hubs and, USB mice., Windows ME, Windows ME was one to skip., Considered a low point in the Windows series by many at least, until they saw Windows Vista - Windows, Millennium Edition was the last Windows to be based on, MS-DOS, and the last in the Windows 9x line., Released in September 2000, it was the consumer-aimed, operating system twined with Windows 2000 aimed at, the enterprise market. It introduced some important, concepts to consumers, including more automated, system recovery tools., IE 5.5, Windows Media Player 7 and Windows Movie, Maker all made their appearance for the first time., Autocomplete also appeared in Windows Explorer, but, the operating system was notorious for being buggy,, failing to install properly and being generally poor., Windows 2000, Windows 2000 was ME's enterprise twin., The enterprise twin of ME, Windows 2000 was released, in February 2000 and was based on Microsoft's businessorientated system Windows NT and later became the, basis for Windows XP., Microsoft's automatic updating played an important role, in Windows 2000 and became the first Windows to, support hibernation., Windows XP, Windows XP still survives to this day., Arguably one of the best Windows versions, Windows, XP was released in October 2001 and brought Microsoft's, enterprise line and consumer line of operating systems, under one roof., Advertisement, It was based on Windows NT like Windows 2000, but, brought the consumer-friendly elements from Windows, ME. The Start menu and task bar got a visual overhaul,, bringing the familiar green Start button, blue task bar, and vista wallpaper, along with various shadow and other, visual effects., ClearType, which was designed to make text easier to, read on LCD screens, was introduced, as were built-in, 26, , Its biggest problem was security: though it had a firewall, built in, it was turned off by default. Windows XP's huge, popularity turned out to be a boon for hackers and, criminals, who exploited its flaws, especially in Internet, Explorer, mercilessly - leading Bill Gates to initiate a, "Trustworthy Computing" initiative and the subsequent, issuance of to Service Pack updates that hardened XP, against attack substantially., Windows Vista, Windows Vista, arguably worse than Windows ME., Windows XP stayed the course for close to six years, before being replaced by Windows Vista in January 2007., Vista updated the look and feel of Windows with more, focus on transparent elements, search and security. Its, development, under the codename "Longhorn", was, troubled, with ambitious elements abandoned in order, to get it into production., Advertisement, It was buggy, burdened the user with hundreds of requests, for app permissions under "User Account Control" - the, outcome of the Trustworthy Computing initiative which, now meant that users had to approve or disapprove, attempts by programs to make various changes., The problem with UAC was that it led to complacency,, with people clicking "yes" to almost anything - taking, security back to the pre-UAC state. It also ran slowly on, older computers despite them being deemed as "Vista, Ready" - a labelling that saw it sued because not all, versions of Vista could run on PCs with that label., PC gamers saw a boost from Vista's inclusion of, Microsoft's DirectX 10 technology., Windows Media Player 11 and IE 7 debuted, along with, Windows Defender an anti-spyware programme. Vista, also included speech recognition, Windows DVD Maker, and Photo Gallery, as well as being the first Windows to, be distributed on DVD. Later a version of Windows Vista, without Windows Media Player was created in response, to anti-trust investigations., Windows 7, Windows 7 was everything Windows Vista should, have been., Considered by many as what Windows Vista should have, been, Windows 7 was first released in October 2009. It, was intended to fix all the problems and criticism faced, by Vista, with slight tweaks to its appearance and a, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished
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concentration on user-friendly features and less "dialogue, box overload"., It was faster, more stable and easier to use, becoming, the operating system most users and business would, upgrade to from Windows XP, forgoing Vista entirely., Handwriting recognition debuted in 7, as did the ability, to "snap" windows to the tops or sides of the screen,, allowing faster more automatic window resizing., , Windows 8.1, Windows 8.1 and the great reappearance of the Start, button., A free point release to Windows 8 introduced in October, 2013, Windows 8.1 marked a shift towards yearly, software updates from Microsoft and included the first, step in Microsoft's U-turn around its new visual interface., , Windows 7 saw Microsoft hit in Europe with antitrust, investigations over the pre-installing of IE, which led to, a browser ballot screen being shown to new users, allowing them to choose, which browser to install on first, boot., , Windows 8.1 re-introduced the Start button, which, brought up the Start screen from the desktop view of, Windows 8.1. Users could also choose to boot directly, into the desktop of Windows 8.1, which was more suitable, for those using a desktop computer with a mouse and, keyboard than the touch-focused Start screen., , Windows 8, , Windows 10, , Windows 8 focused more on touch than a keyboard, and mouse., , With Windows 10, Microsoft is trying to keep some of, the touch and tablet features it created for Windows 8,, combine them with the familiar Start menu and desktop,, and run it all on top of an improved operating system, with more security, a new browser, the Cortana assistant,, its own version of Office for on-the-go editing and plenty, of new features intended to make life simpler., , Released in October 2012, Windows 8 was Microsoft's, most radical overhaul of the Windows interface, ditching, the Start button and Start menu in favour of a more touchfriendly Start screen., Advertisement, The new tiled interface saw programme icons and live, tiles, which displayed at-a-glance information normally, associated with "widgets", replace the lists of, programmes and icons. A desktop was still included,, which resembled Windows 7., , Of course, that also means it's very different to use,, whether you come from Windows 7, Windows 8 or, Windows XP. You have to look in a new place even to, turn your PC off., , Windows 8 was faster than previous versions of Windows, and included support for the new, much faster USB 3.0, devices., , On top of that, Windows 10 is more than just a PC, operating system; it's also what will run on Windows, phones - and on small tablets as well, because a 6-inch, phone and a 7-inch tablet aren't such very different, devices., , The Windows Store, which offers universal Windows, apps that run in a full-screen mode only, was introduced., Programs could still be installed from third-parties like, other iterations of Windows, but they could only access, the traditional desktop interface of Windows., , Microsoft is expecting people to put Windows 10 on a, billion devices (which ought to encourage more app, developers to at least take a look at building their apps, for Windows phones and tablets, as well as for Xbox, One and HoloLens)., , The radical overhaul was not welcomed by many., Microsoft attempted to tread a fine line between, touchscreen support and desktop users, but ultimately, desktop users wanting to control Windows with a, traditional mouse and keyboard and not a touchscreen, felt Windows 8 was a step back., , The Start menu evolves, , There were also too few touchscreens in use, or on offer,, to make its touch-oriented interface useful or even, necessary - despite the parallel rise of tablets such as, the iPad, and smartphones, which had begun outselling, PCs by the end of 2010., , The full-screen Start screen of Windows 8 is back to, being a Start menu in Windows 10 that tries to combine, the best of both options. A scrolling Start menu that's, restricted to a single column, with jump lists and flyout, menus for extra options, divided into frequently used, and recently installed programs, with the option to switch, to a scrolling view of all the applications, sorted, alphabetically., Fig 1, , It looked and felt like Windows 8, but could not run, traditional Windows applications, instead solely relying, on the Windows Store for third-party apps., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13701, , Windows RT, which runs on ARM-based processors, traditionally found in smartphones and non-PC tablets,, was introduced at the same time as Windows 8 with the, Microsoft Surface tablet., , 27
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But also get an extra pane ,where can pin Windows 8style tiles, complete with 'rotating 3D cube' animations of, live tiles. drag the Start menu to be a larger size or even, set it to be full screen., Desktop Background, Another component of the Desktop is the Background., This is simply an image that appears at the back of the, screen. Most computers come with a pre-selected, background, but change it to any image., , alternative is to use the File Explorer by clicking on the, Folder icon on the Taskbar., In the File Explorer window, browse all the folders and, documents., Fig 4, , To change the background, follow these steps:, 1. Right-click on the background and choose, "Personalize", 2. From the Personalization window, choose from a series, of pre-selected pictures or browse for your own., After choosing a picture, the Background will change, automatically., Copa 13704, , Start Menu, If looking for a specific application, open the Start Menu, and click "All Applications". This will open an alphabetical, , Fig 2, , Virtual Desktops, One of the new features of Windows 10 is the addition of, Virtual Desktops. This allows you to have multiple desktop, screens where to keep open windows organized., , Copa 13705, , Copa 13702, , Fig 5, , list of all the applications installed on computer., , To add a virtual desktop, follow these steps:, , Fig 3, , File Explorer, If you are looking for a specific document, another, , 28, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , Copa 13706, , Copa 13703, , Fig 6
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1. Click Task View on the Taskbar, 2. Click the "New desktop" option on the lower-right corner., You can access or delete the new Desktop by clicking, Task View again., Cortana helps as with search and control, Cortana, the Windows Phone assistant, shows up in, , Fig 7, , If Cortana isn't active, can turn it on by typing "Cortana" in, the Taskbar search to access the Cortana settings, or, just clicking the "Gear" icon on the left-side of the menu., After activating Cortana, it will start gathering information, about to personalize the experience., Task switcher, Most Windows users don't know the Alt-Tab keyboard, , Copa 13707, , Fig 10, , Windows 10 as a search pane on the taskbar, which can, also trigger by saying 'Hey Cortana' - and when start, searching the Start menu., Fig 8, , combination to see and switch between all running apps,, so as well as having a redesigned task switcher with bigger, , Copa 13708, , Fig 11, , That gets theapps have installed, documents access to,, apps could install from the Store, search results from the, web and a range of other information - including from apps, and services that integrate with Cortana., Activating Cortana, , Copa 137011, , Fig 9, , thumbnails, Windows 10 also puts a task view icon in the, taskbar to help them find it., Copa 13709, , TASKBAR, The Windows 10 taskbar sits at the bottom of the screen, giving the user access to the Start Menu, as well as the, icons of frequently used applications. On the right-side,, the Taskbar features the Notification Area which informs, the user of different things like the state of the Internet, connection or the charge of the laptop battery., The icons in the middle of the Taskbar are "pinned", applications, which is a way to have a quick access to, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.07- 1.3.11, , Copyright @ NIMI Not to be Republished, , 29
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applications you use frequently. "Pinned" applications, will stay in the Taskbar until you "unpin" them., , Copa 1137012, , Fig 12, , Taskbar. It shows different types of notifications from your, computer like your Internet connection, or the volume level., At first, the Notification Area shows a limited amount of, icons. But you can click the upward arrow on its left-side, to see other icons as well., Snap Assist, Because all the apps and programs run in windows on the, Fig 15, , Pin an Application to the Taskbar, Copa 137015, , Step 1: Search for the application you want to pin in the, Start Menu., Step 2: Right-click on the application., Step 3: Select "More" option at the top of the menu., Step 4: Select the "Pin to taskbar" option., Unpin an Application from the Taskbar, To "unpin" it, just right-click the icon in the Taskbar and, select "Unpin from taskbar". You can "pin" it back again, , desktop, instead of modern apps from the Store being in, their own space, and can no longer drag across the left, edge of the screen to bring another app on screen and get, a split view. Instead, drag windows into the corners of the, screen to get the familiar Snap view., Now use all four corners of the screen if want each window, to take up a quarter of the screen instead of half, and the, space that isn't filled by the window you just dragged shows, thumbnails of your other windows to make it easier to, snap the next one into place., , Fig 13, , Action Center, , Copa 137013, , If we used Windows Phone 8.1 (or Android and/or iOS),, we used to a notification centre can drag down from the, top of the screen., , any time you want., Notification Area, The Notification Area is located at the right side of the, , Fig 14, , The command prompt, Those of us that use the command prompt have been, stuck with pretty much the same experience since the, 1990s, but in Windows 10 can finally resize the, command prompt window and use familiar keyboard, shortcuts to copy and paste at the command prompt., It's far from ground-breaking but it's a very welcome, improvement after years of frustration., FILE EXPLORER, , Copa 137014, , 30, , Windows 10 puts that on the right of the screen, where, the charms bar was in Windows 8, with notifications from, various apps at the top and the choice of various settings, buttons at the bottom for quick access., , File Explorer is the file management application used, by Windows operating systems to browse folders and, files. It provides a graphical interface for the user to, navigate and access the files stored in the computer., The main way to access the File Explorer is by clicking, the folder icon in the Taskbar. After clicking the icon, the, File Explorer window will open., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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Multiple desktops, , Fig 15, , User need to arrange a lot of windows and don't have, multiple monitors, user can put them on multiple virtual, desktops. And can use Alt-Tab to move between apps, as usual and then Windows-Ctrl and the left and right, arrow keys to move between desktops., , Copa 137015, , Schedule restarts, , The initial File Explorer window is comprised of the following, sections:, 1. The File Explorer ribbon, which resembles the ribbon, featured in Microsoft Office. The ribbon contains buttons, for common tasks to perform with your files and folders., 2. The Navigation Pane gives you access to your, libraries of documents and pictures, as well as your, storage devices. It also features frequently used folders, and network devices., 3. The Frequent folders section on the right features, the folders you've worked with recently to allow for quick, access to them., 4. The Recent files section in the lower part of the, window features files and documents that you've opened, recently., The new Edge browser, To catch up with fast-moving browsers like Chrome and, Firefox, Microsoft took its browser back to basics, ripping, out years of code that didn't fit with web standards and, making a lean, fast browser., It's a work in progress - it won't get support for things like, ad-blocking extensions until a while after Windows 10, launches - but can do plenty of neat things here. For, example, and can scribble notes on a web page to send, to a friend and Edge has Cortana built in to pull useful, information out of web pages, like the phone number of, a restaurant, or the opening hours., Sites like Medium that didn't work properly with IE should, look better and have more features in Edge., , No more having Windows announce that you have fifteen, minutes to get everything done before it restarts to apply, an update. Instead of leaving Windows 10 to decide when, to do that, if there's an update that will need a restart, and can have Windows ask when you want to schedule, that for., user can only do that once the update has been, downloaded. If user want to have certain times off-limits, for restarts, they will need the features in Windows, Update for Business (for Windows 10 Pro and Enterprise), which lets block restarts so they don't happen in working, hours, or on certain dates., Universal apps - including Office, Windows 10 gets a new Windows Store, where download, desktop programs as well as modern Windows apps., Many of those apps will be universal apps that are the, same code on a PC, a Windows phone, an Xbox One, and even on HoloLens, with the interface changing to, suit the different screen sizes. The Office for Windows, apps like Word and Excel are universal apps, as are the, Outlook Mail and Calendar apps., Settings and control panel, The Windows 8 Settings app has taken over many more, of the settings that used to be in Control Panel, and it, has a Control Panel-style interface with icons to navigate, with. But the old Control Panel interface is still there, for, settings that aren't in the new Settings app (or if you're, just used to finding things there)., Windows 10 - Keyboard ShortcutsUTS, Like most Windows applications, there are several, keyboard shortcuts you can use to make it easier or faster, for some to perform certain tasks., Most of the new Windows shortcuts use the Windows, key () combined with other keys to perform several, actions. The following are some of the most common or, useful shortcuts used in Windows 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished, , 31
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Keyboard Shortcuts for Navigating Windows 10, Press This, , 32, , To Do This, , Windows Logo, , Toggle the Start menu, , Windows Logo+A, , Open the Notifications pane, , Windows Logo+B, , Activate the notification area's Show Hidden Icons arrow (press Enter to display, the hidden icons), , Windows Logo+C, , Open Cortana for voice commands, , Windows Logo+D, , Minimize all open windows to display the desktop, , Windows Logo+E, , Run File Explorer, , Windows Logo+F, , Display the Start menu and activate the Search box, , Windows Logo+H, , Display the Share pane, , Windows Logo+I, , Run the Settings app, , Windows Logo+K, , Display the Devices pane, , Windows Logo+L, , Lock your computer, , Windows Logo+M, , Minimize all windows, , Windows Logo+O, , Turn the tablet orientation lock on and off, , Windows Logo+P, , Display the Project pane to configure a second display, , Windows Logo+Q, , Open Cortana for voice commands, , Windows Logo+R, , Open the Run dialog box, , Windows Logo+S, , Open Cortana for keyboard commands, , Windows Logo+T, , Activate the taskbar icons (use the arrow keys to navigate the icons), , Windows Logo+U, , Open the Ease of Access Center, , Windows Logo+W, , Activate the Search box, , Windows Logo+X, , Display a menu of Windows tools and utilities, , Windows Logo+Z, , Display an app's commands (although this works in only some Modern apps), , Windows Logo+=, , Open Magnifier and zoom in, , Windows Logo+-, , Zoom out (if already zoomed in using Magnifier), , Windows Logo+,, , Temporarily display the desktop, , Windows Logo+Enter, , Open Narrator, , Windows Logo+Left, , Snap the current app to the left side of the screen, , Windows Logo+Right, , Snap the current app to the right side of the screen, , Windows Logo+Up, , Restore a minimized app; maximize a restored app, , Windows Logo+Down, , Restore a maximized app; minimize a restored app, , Windows Logo+PgUp, , Move the current app to the left monitor, , Windows Logo+PgDn, , Move the current app to the right monitor, , Windows Logo+PrtSc, , Capture the current screen and save it to the Pictures folder, , Windows Logo+Ctrl+D, , Create a virtual desktop, , Windows Logo+Ctrl+Right, , Switch to the next virtual desktop, , Windows Logo+Ctrl+Left, , Switch to the previous virtual desktop, , Windows Logo+Ctrl+F4, , Close the current virtual desktop, , Windows Logo+Tab, , Open Task View, which displays thumbnails for each running app as well as, the available virtual desktops, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.03.01, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Windows Opeating System, , Related Theory for Exercise 1.3.12, , Handling printers, Objectives : At the end of this lesson you shall be able to, • explain about typewriter, • explain about printer, • explain types and cost of printers, • explain programming languages for printers, • explain how to locate printer driver files., Typewriter, A typewriter is a mechanical or electromechanical device, with keys that, when pressed, cause characters to be, printed on a medium, usually paper as on Fig 1. Typically, one character is printed per keypress, and the machine, prints the characters by making ink impressions of type, elements similar to the sorts used in movable type, letterpress printing., , Fig 2, , Fig 1, , Fig 3, , After their invention in the 1860s, typewriters quickly, became indispensable tools for practically all writing other, than personal correspondence. They were widely used, by professional writers, in offices, and for business, correspondence in private homes. By the end of the, 1980s, word processors and personal computers had, largely displaced typewriters in most of these uses., Computer printer, A printer is a piece of hardware for a computer as on, Fig 2. It is a device that must be connected to a computer, which allows a user to print items on paper, such as letters, and pictures. It can also work with digital cameras to, print directly without the use of a computer., Types of printers, Today, the following types of printers are in regular use:, Daisy wheel printing is an impact printing technology, invented in 1969 by David S. Lee atDiablo Data Systems, as on Fig 3. It uses interchangeable pre-formed type, elements, each with typically 96 glyphs, to generate highquality output comparable to premium typewriters such, , as theIBM Selectric, but two to three times faster. Daisy, wheel printing was used in electronic typewriters, word, processors and computers from 1972. According to, Webster's, the daisy wheel is so named because of its, resemblance to the daisy flower., , Copyright @ NIMI Not to be Republished, , 33
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Dot-matrix printers are now almost extinct. They used a, ribbon and made a lot of noise. There were models with, 9 pins and models with 24 pins as on Fig 4. A dot matrix, printer or impact matrix printer is a type of computer, printer with a print head that runs back and forth, or in an, up and down motion, on the page and prints by impact,, striking an ink-soaked cloth ribbon against the paper,, much like the print mechanism on a typewriter., , Fig 6, , Fig 4, , such wide-format printers as "plotters," even though they, technically are not., , Inkjet printing is a type of computer printing that creates, a digital image by propelling droplets of ink onto paper, as on Fig 5. Inkjet printers are the most commonly used, type of printer, and range from small inexpensive, consumer models to very large professional machines, that can cost tens of thousands of dollars., , Pen plotters print by moving a pen or other instrument, across the surface of a piece of paper. This means that, plotters are restricted to line art, rather than raster, graphics as with other printers. Pen plotters can draw, complex line art, including text, but do so slowly because, of the mechanical movement of the pens. They are often, incapable of efficiently creating a solid region of color,, but can hatchan area by drawing a number of close,, regular lines., Laser printing is a digital printing process that rapidly, produces high quality text and graphics on plain paper., As with digital photocopiers and multifunction printers, (MFPs), laser printers employ a xerographic printing, process, but differ from analog photocopiers in that the, image is produced by the direct scanning of a laser beam, across the printer's photoreceptor., , Fig 5, , A laser beam projects an image of the page to be printed, onto an electrically charged rotating drum coated with, selenium or, more common in modern printers, organic, photoconductors. Photoconductivity allows charge to leak, away from the areas exposed to light., , The concept of inkjet printing originated in the 20th, century, and the technology was first extensively, developed in the early 1950s. Starting in the late 1970s, inkjet printers that could reproduce digital images, generated by computers were developed, mainly by, Epson,Hewlett-Packard (HP), and Canon. In the, worldwide consumer market, four manufacturers account, for the majority of inkjet printer sales: Canon, HP, Epson,, and Lexmark, a 1991 spin-off from IBM., The plotter is a computer printer for printing vector, graphics as on Fig 6. In the past, plotters were used in, applications such as computer-aided design, though they, have generally been replaced with wide-format, conventional printers. It is now commonplace to refer to, 34, , Dry ink (toner) particles are then electro statically picked, up by the drum's charged areas, which have not been, exposed to light. The drum then prints the image onto, paper by direct contact and heat, which fuses the ink to, the paper., Cost of printers, There are different costs with a printer. Printers that are, more expensive to buy will usually be less expensive in, the consumables (the ink, toner, or ribbon used by the, printer). Therefore, laser printers are often more, expensive to buy than inkjet printers, but are not, expensive to use over a long period of time., Inkjet printers on the other hand have a higher cost of, consumables because the ink tanks they use are more, expensive than the toner for a laser printer., Laser printers that can print in color are usually more, expensive than those that only print in black and white., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished
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Other options, like being able to print on both sides of a, sheet of paper, to automatically sort the output, or to, staple the output will also make a printer more expensive., , Fig 7, , Common programming languages for printers, include:, ESC/P, , •, , Postscript, , •, , PCL, , •, , GDI, , •, , HPGL and HPGL/2, , •, , PDF, , Prominent features of a scanner include:, , •, , VPS, , •, , Reliability - Unlike certain forms of data transmission,, scanning involves only transfer of hard images to, digital forms. The role of the end-user is limited in, case of scanning. And as they are not dependent on, two-way communication, they can also help in storing, important information or transmitting important, information., , •, , Efficiency - Modern scanners are built for efficiency, and speed. And it comes with ease of use as well as, convenience., , •, , Quality - Scanning ensures the best resolution, possible for digital images. Compared to fax, machines, which may find it difficult to reproduce the, accurate details, scanners can reproduce images with, high resolution and precisions. They are quite useful, for photography and engineering arenas., , •, , Cost saving - One of the biggest advantage of, scanning is the replacement of physical files/forms, with digital ones. Along with saving physical space,, which has to be used for storage, there are also, environmental benefits by using scanner., , Copa 110107, , •, , How to Locate Printer Driver Files, Printers can be connected to a computer by a variety of, wired and wireless methods, but all printers require, drivers to be installed on a computer. The printer drivers, are small programs that help communicate information, from the operating system to the printer., Driver errors can make the printer unusable. Using the, Windows device manager, you can look up details about, the drivers as well as pinpoint their physical location on, your hard drive., Scanner, A scanner is an electronic device which can capture, images from physical items and convert them into digital, formats, which in turn can be stored in a computer, and, viewed or modified using software applications., Different types of scanners are available with different, resolutions. In the world of electronic data transmission,, scanning is considered to be the most cost-effective and, reliable way of transmitting images., The basic principle of a scanner is to analyze an image, and reproduce it to a digital one using the optical, character recognition techniques., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.3.12, , Copyright @ NIMI Not to be Republished, , 35
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IT & ITES, Related Theory for Exercise 1.4.13, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., The Basic Input/Output System (BIOS), also known as, System BIOS, ROM BIOS or PC BIOS is a generally, accepted standard defining a firmware interface., , •, , The fundamental purpose of the BIOS is to initialize and, test the system hardware components and load an, operating system from a mass memory device. The BIOS, is special software that interfaces the major hardware, components of the computer with the operating system., It is usually stored on a Flash memory chip on the, motherboard, but sometimes the chip is another type of, ROM. The BIOS is a firmware (software instructions, permanently recorded on a chip located on your, motherboard). (Refer Fig.1)., , The first thing the BIOS will do is check the information, stored in a tiny (64 bytes) amount of RAM located on a, complementary metal oxide semiconductor (CMOS), chip. The CMOS Setup provides detailed information, particular to your system and can be altered as your, system changes. The BIOS uses this information to, modify or supplement its default programming as, needed., , Copa 181301, , Fig 1, , Functions of BIOS, The BIOS software has a number of different roles, but, its most important role is to load the operating system., The BIOS checks and initializes the PC hardware each, time the system powers up or restarts before handing, over control to the operating system. Some of the other, common tasks that the BIOS performs include:, •, , A power-on self-test (POST) for all of the different, hardware components in the system to make sure, everything is working properly, , •, , Activating other BIOS chips on different cards installed, in the computer - For example the graphics cards often, have their own BIOS chips., , •, , Providing a set of low-level routines that the operating, system uses to interface to different hardware, devices. They manage things like the keyboard, the, screen, and the ports, especially when the computer, is booting., , 36, , Managing a collection of settings for the hard disks,, clock, etc., , CMOS Setup, , Configuring BIOS, The BIOS checks the CMOS Setup for custom settings., To change the CMOS settings we need to enter the, CMOS setup. To enter the CMOS Setup, a certain key, or combination of keys must be pressed during the initial, startup sequence. Most systems use "Esc," "Del," "F1,", "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. There is, usually a line of text at the bottom of the display that, tells "Press ___ to Enter Setup.", The BIOS setup shows a set of text screens with a, number of options. Some of these are standard, while, others vary according to the BIOS manufacturer., Common options include:, •, , System Time/Date - Set the system time and date, , •, , Boot Sequence - The order that BIOS will try to load, the operating system, , •, , Plug and Play - A standard for auto-detecting connected, devices; should be set to "Yes" if your computer and, operating system both support it, , •, , Mouse/Keyboard - "Enable Num Lock," "Enable the, Keyboard," "Auto-Detect Mouse"..., , •, , Drive Configuration - Configure hard drives, CD-ROM, and floppy drives, , •, , Memory - Direct the BIOS to shadow to a specific, memory address, , •, , Security - Set a password for accessing the computer, , •, , Power Management - Select whether to use power, management, as well as set the amount of time for, "standby" and "suspend", , Copyright @ NIMI Not to be Republished
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•, , Exit - Save your changes, discard your changes or, restore default settings., , The BIOS uses CMOS technology to save any changes, made to the computer's settings. With this technology, a, small lithium or Ni-Cad battery can supply enough power, to keep the data for years. Major BIOS manufacturers, include American Megatrends Inc. (AMI), Phoenix, Technologies, Winbond etc. A typical BIOS screenshot, is shown in fig. given below.(Refer Fig.2), Fig 2, , •, , Use of multi-boot setups, which allow users to have, more than one operating system on a single computer., For example, one could install Linux and Microsoft, Windows or other operating systems on different, partitions of the same HDD and have a choice of, booting into any operating system at power-up., , •, , Protecting or isolating files, to make it easier to recover, a corrupted file system or operating system installation., If one partition is corrupted, other file systems may not, be affected., , •, , Raising overall computer performance on systems, where smaller file systems are more efficient., , •, , Partitioning for significantly less than the full size, available can reduce the time for diagnostic tools such, as checkdisk to run., , Copa 181302, , Formatting, , Installing the Windows operating System, A hard disk needs to be partitioned (though not, mandatory) and formatted before you can store data, on it., Partitioning, A partition, sometimes also called a volume, is an area, on a hard disk that can be formatted with a file system, and identified with a letter of the alphabet. For example,, drive C on most Windows computers is a partition. the, first three partitions you create are primary partitions., These can be used to start an operating system. If you, want to create more than three partitions, the fourth, partition is created as an extended partition., An extended partition is a container that can hold one or, more logical drives. Logical drives function like primary, partitions except that they cannot be used to start an, operating system., Many computers are partitioned as a single partition that, equals the size of the hard disk. Partitioning a hard disk, into several smaller partitions is not required, but it can, be useful for organizing data on your hard disk., Creating more than one partition has the following, advantages:, •, , Separation of the operating system (OS) and program, files from user files., , •, , Having a separate area for operating system virtual, memory swapping/paging., , •, , Keeping frequently used programs and data near each, other., , Disk formatting is the process of preparing a data storage, device such as a hard disk drive, solid-state drive or, USB flash drive for initial use. It is the act of creating a, file system on a volume, so that the operating system, can store and retrieve data on that volume., Formatting of a disk is of two categories:, 1 Low-level formatting (i.e., closest to the hardware), marks the surfaces of the disks with markers, indicating the start of a recording block. It also, provides information about block checks done for, future use by the disk controller to read or write data., This is intended to be the permanent foundation of, the disk, and is often completed at the factory. A hard, disk needs to be partitioned and formatted before you, can store data on it, 2 High-level formatting creates the file system format, within a disk partition or a logical volume. This, formatting includes the data structures used by the, OS to identify the logical drive or partition's contents., This may occur during operating system installation,, or when adding a new disk., Installing the Windows operating System, The three basic types of windows installation procedures, are as follows:, •, , Install on a brand new disk or computer system, , •, , Erase the disk, format it, and install., , •, , Install into a new directory for dual-booting, , For the first two methods, it must be ensured that the, computer can boot from a DVD or any other removable, drive. To do this the drive boot order needs to be changed, in the BIOS. The latest Windows DVDs are bootable, and run the Setup program automatically. Then the, installation can be done by following the procedure step, by step as indicated on the subsequent screens as in, trade practicals., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.13, , Copyright @ NIMI Not to be Republished, , 37
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IT & ITES, Related Theory for Exercise 1.4.14 & 1.4.15, COPA - Computer basics & Software installation, CMOS setup and windows installation, Objectives : At the end of this lesson you shall be able to, • describe the functions of BIOS and CMOS, • describe the method of viewing and changing BIOS settings, • describe the meaning of partitioning and formatting, • describe the process of installing Windows operating system., Format a hard drive, , Format hard drive partitions, It's important to understand about partitions before getting, started. A hard drive can be divided up into smaller, sections, called partitions. It's possible to format one, partition while leaving the others untouched., , Fig 1, , If it isrequired to format the entire hard drive and use the, entire capacity in one block, delete the partition, information., Format a hard drive from the BIOS?, , Copa 110101, , Many people ask how to format a hard disk from BIOS., The short answer is no., , There are many reasons why it is required to format a, hard drive, such as to install Windows fresh, to get rid of, a virus or malware or simply because a pc is refreshed, or cleaned up on selling., , If it is required to format a disk and you can't do it from, within Windows, create a bootable CD, DVD or USB flash, drive and run a free third-party formatting tool., One option is Darik's Boot and Nuke (DBAN), which is, free for personal use. This program will totally erase and, format your hard disk, allowing for a clean install of a, new OS, but the process cannot be undone., Fig 2, , The process can be different depending on whether it's, an only hard drive and whether there is a spare PC or, not., , Copa 110102, , It cannot be formatted, the hard drive on which Windows, is running. In order to do this, it is in need to boot the PC, from a Windows installation disc, a USB flash drive or, another bootable disc., Format a disk?, Formatting is the process of deleting all the data on the, hard drive, but beware of 'Quick Format' which leaves, all data in place and makes the drive appear to be empty., A quick format is ok if there is a brand new hard drive, or, need to reinstall Windows, but not if its disposing of the, disk or giving it to someone else., , DBAN is supposedly only able to create a bootable CD/, DVD-R, but if don't have any blank discs or a burner,, there is a workaround available in the form of a separate, third-party program., , A word of warning: make sure to have successfully, backed up any photos, videos, music and other, documents from the drive before formatting it. Although, deleted files can be recovered in some situations,, prevention is always better than cure., , Universal USB Installer will quickly and easily convert, the DBAN ISO image downloaded to run from a bootable, USB. Simply insert a blank USB flash drive, run the, Universal USB Installer setup program, and follow the, prompts., It will ask to scroll through and pick the Linux Distribution, want to install to USB (in this case, the latest version of, DBAN), followed by its location on the computer and the, letter of the USB drive like to install it to., , 38, , Copyright @ NIMI Not to be Republished
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Once that information is complete, click create., , Copa 191503, , To boot from this USB drive rather than usual boot device, (in most cases, this would be the hard drive), it have to, be changed some settings in the BIOS., In the BIOS, navigate to the boot order settings, and, change the primary boot device to the USB drive (it, shouldn't need to be plugged in to make this selection)., After saved the settings and exited the BIOS, insert the, bootable USB, restart the computer., , Copa 191505, , Fig 5, , Fig 3, , By default Quick Format is checked, and choose the file, system and allocation unit size as well as changing the, volume label (the drive's name). Typically, leave all, settings unchanged and click the Start button. In under a, minute the hard drive will be formatted., , Fig 6, , Copa 191504, , Fig 4, , It will treat the USB as another drive so to avoid, inadvertently wiping that as well, remove it after booted, into DBAN., Quick format a hard drive?, Yes, but don't use this method if want the data to be, permanently erased. A quick format doesn't delete the, data but instead erases only the pointers to the files., Windows Vista, 7, 8 and 10 have a built-in Disk, Management tool (see below), but the fastest way to, format a hard drive is to click the Start button, then, Computer and right-click on the hard drive to wipe. It, can't be formatted the drive on which Windows is installed, for obvious reasons., , Copa 191506, , The PC should automatically boot the DBAN software,, which will guide through the process of erasing the hard, drive, with options for different levels of data-wiping., , Choose NTFS as the file system if it isn't already selected, for Windows Vista, 7, 8 or 10 and ensure the Allocation, Unit Size is set to 'Default Allocation Size'., Using the Disk Management tool, Type diskmgmt.msc or Disk Management into the search, box in Vista, 7, 8 or 10 and then click on only result that, appears in the menu above, with the same name., This is the easiest way to launch Disk Management, but, also find it in the Control Panel if search for 'disk' and, select the 'Create and format hard disk partitions'., Disk Management isn't as powerful as a standalone, partition management tool, but it is still capable of, formatting data., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 39
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If select a size for the partition that's smaller than the total, capacity of the drive, say 500B on a 1TB drive, end up, with some unallocated space on the drive which can format, by repeating the process just completed., , Fig 7, , change partition size, Disk Management can be used to expand or shrink a, partition. Simply right-click on one and choose the, appropriate option from the menu that appears. If, shrinking, the partition will be checked to find out how, much empty space it contains., , If it is to install a new (additional) hard drive in a PC, it, might be a thing to wonder why it doesn't appear in Windows, Explorer. The reason is because it needs to be initialised, and formatted -which can be done in Disk Management., When the tool loads, it will analyse all of the computer's, drives and will prompt to initialise a new disk that it finds., , Fig 8, , Copa 191509, , Copa 191507, , Fig 9, , It's a little confusing as the numbers are displayed in MB, rather than GB, but it can be adjusted the amount of, space to shrink and the 'Total size after shrink' will be, updated, alsocan't shrink a partition beyond the point, where files are located - it may be able to free up space, by defragmenting the drive first., Conversely it can only expand a partition if there is, unused space on the drive. If not, the option will be greyed, out., , Copa 191508, , Resetting Windows, If PC is having problems and the user don't wish to lose, the personal files by wiping the hard drive, then it might, want to refresh or reset the PC which can be done in, Windows 8 and 10., If user looking to keep your personal files and settings,, but want to have a fresh Windows install, itsall want to, refresh the PC., , If the disk is larger than 2TB, opt for GPT (GUID Partition, Table). This setting also lets to create more than four, partitions., , Do note that a refresh will remove all programs and apps, installed on the machine, but will keep the Windowsdefault programs intact., , If don't see a prompt, look in the list of drives and see, one that says 'Not Initialized'. Right-click on it and choose, Initialize Disk., , A reset reinstalls Windows and deletes all files, settings, and programs, it is suggested performing this if have, previously backed up all the files and don't mind, transferring user's personal files., , Once that's done, right-click in the hatched Unallocated, space and choose New Simple Volume…, Follow the instructions, choosing how big to want the, partition to be (in MB - 1024MB = 1GB), and which drive, letter to assign (one will be chosen, but can opt to change, it if desired)., , 40, , Windows 10 has a slightly different approach and might, confuse those coming from Windows 8. Microsoft, removed the refresh option and has instead combined, the refresh and reset options into one setting., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished
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Copa 1915010, , Fig 10, , To find the option, open the Start Menu, click on Settings, > Update & security > Recovery > Get started (under, the Reset this PC option)., , 'Keep my files' saves personal files but deletes user, settings, drivers and programs, whilst also reinstalling, Windows 10., , Upon selecting the option, it will present with three, separate options:, , 'Remove everything' also gets rid of personal files and, 'Restore factory settings' does the same actions as, 'Remove everything', but also resets the PC to the version, of Windows which came with the machine., , •, , Keep my files, , •, , Remove everything, , •, , Restore factory settings (not available on all PCs), , This option will only be available to those who bought a, pre-built PC or laptop which came with Windows already, pre-installed., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.14 & 1.4.15, , Copyright @ NIMI Not to be Republished, , 41
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IT & ITES, Related Theory for Exercise 1.4.16, COPA - Computer basics & Software installation, Troubleshooting computer, Objectives: At the end of this lesson you shall be able to, • state the basic steps involved in troubleshooting a PC, • explain the basic approach to solve a problem, • list the probable defects and symptoms in a faulty Computer, • analyse the causes for the complaints, • state the shortest path for servicing the defects., • list the probable defect and symptoms in the faulty Computer, • analyse the causes for the complaint “When windows is started, system runs surface test and goes to, safemode” with the help of a Problem Tree and TSC, Basic Troubleshooting, One of the difficulties while troubleshooting problems on, a PC is that in most cases they are not what they seem., The cause behind a frequent hanging of a PC may be due, to one of six or more well defined areas or a dozen of, unidentified problems. The problem could be due to, software or hardware. Even with years of experience and, training, PC technicians come out with troubleshooting, procedures that do not solve the real problem. For, example a personal computer running windows operating system with several i/o cards connected may freeze, the screen , mouse, and keyboard and take as long as 3, minutes before responding. After trying out with all the, options like replacing a memory module, installing new, parallel port and NIC drivers, the technician finally checks, the system logs to find that a vital operating system, library was corrupted and needed to be reinstalled. The, issue to be mentioned here is that if the technician used, a systematic approach to troubleshooting, the problem, would likely have been solved much sooner. Maintaining, a good troubleshooting plan certainly gives us the scope, to approach the problem in a more systematic and, scientific manner. A troubleshooting plan is nothing but, a written check list that we use for any problem. The, elements that should be included in any troubleshooting, plan are as follows, – Maintenance record, – Identification of possible causes, – Identification of possible solutions, – Application and testing of solutions, – Follow-up, In the maintenance record, record the hardware installed, in the PC when it is installed, all preventive maintenance, activities, all software updates or additions, and all, hardware installations and upgrades. Further any problems that occur and the actions you take to resolve them, should be recorded . when it comes to troubleshooting a, PC, with the maintenance record one can pin down a, problem and devise solution for it. The first entry in such, record should be a profile of the PC, which includes its, configuration, operating system, and the date each, component was installed., 42, , Such tables gives an idea of the type of information one, should include in the sytem configuration, as summerised, below:, – The processor’s make, model and speed., – Amount of system memory(RAM) and the memory, module type, size and configuration of the memory, – Hard disk size and the type of interface, – Make, model and speed of the compact disk (CD) or, digital versatile disk ( DVD) drive, – Memory size of the video or graphics adapter, – Make, model, type and speed of the modem, – The version number of the operating system, – A list of software applications installed on the PC, – A list of peripheral equipment attached to the PC,, indicating the port to which they are attached, The maintenance record should be updated each time any, maintenance work is carried over on the PC. Any time new, or replacement hardware is installed, record the activity, and update the system configuration. The activity entries, should include, – Date of the activity or changes made to the system, – The make, model and serial number of any hardware, removed or added to the PC, – The name, version and publisher of any software added, to the PC, – Detailed information on any configuration changes, made to the basic input/output system(BIOS) or other, configuration for the new device or software., Troubleshooting approach, For solving any problems associated with PC, first go, through the maintenance record of that PC and follow a, systematic procedure for isolating the problem. The, standard problem solving process includes the following, steps, Identify the problem: This is the most difficult part of the, process. To perform this step successfully collect all the, data about the problem, , Copyright @ NIMI Not to be Republished
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Identify possible causes: analyse all the symptoms of, the problem and try to list all the causes in order from the, most likely to the least likely., Identify possible solutions: identify solutions for each of, the causes that are identified. A possible cause could have, more than one possible solution., Analyze the possible solutions: if two solutions produce the same result, consider the one which is more, economic and apply the same., After following the above steps and on solving the, problem update the maintenance record and make, necessary entries into it. In some cases the problems, may be very clear and the solution is very transparent and, even in such cases try to follow the above mentioned steps, to make it a practice to follow the systematic approach., Whenever a problem occurs with a PC, while following the, steps, try to collect the information about the system by, answering questions such as, – Under what circumstances this problem cropped up?, – Were there any indications in the form of beep codes/, error messages or any clear symptoms?, – What softwares were active when the problem happened?, – Has it happened for the first time or occurred in the past, also?, – Were there any configuration changes made during, the session that required a restart that was not, performed?, Optimizing the PC:, A PC which was functioning absolutely well and developed, a symptom of slowing down or if it is unable to keep pace, with the demands of newer software, one of the possible, solutions is to consider updating or optimizing the PC to, enhance its performance. Optimization steps may cost, money , but many involve software you already own or, software readily available on the web., , they are installed out of order, but there is some benefit to, be gained from putting them in the proper sequence. On a, Pentium system, use PCI cards and avoid ISA cards, if, possible. All I/O adapters including video cards, sound, cards, NICs, modems and SCSI adapters are available for, the PCI expansion bus. Consult the motherboard documentation and install video card in the first PCI slot,, followed by the NIC, modem, and sound card, in that order., Optimizing the processor: One can speed up the processor in the following ways, – Replace it with a faster speed or higher level processor, – Use a utility from the processor manufacturer to apply, patches or fixes to the processor’s logic, – Overclock the processor, The requirement for replacing the processor with a higher, level or faster processor is that your motherboard and, chipset will support the new processor both logically and, physically. Logically the chipset and motherboard must, support the bus speed of the processor and have the, supporting circuits it requires. It is often much better to, replace the complete motherboard. Some times the manufacturer of the processor may release some utilities that, will improve some aspect of processor’s capabilities such, as video processing, buffer handling, caching and other, processor based functions. Overclocking a processor, means running a processor at speeds faster than it was, released to support. Most processors are capable of, running at speeds higher than their nominal speeds. The, nominal speed of a processor is the speed at which it has, been tuned to run with a certain chipset, motherboard,, cooling system, and other components of the PC. Raising, the speed of the processor can create heating problems on, the processor and lead to frequent system lockups,, memory problems and other issues., Troubleshooting sources of Non-software problems:, Any time pc fails for no apparent software reason, check, the following areas, , Optimizing the BIOS and Boot process:, , – Ensure proper AC power, , BIOS setup configuration includes many settings in the, CMOS. How quickly the system boots and performs, depends on the these settings. Enabling of valuable, features such as system caching or using the quick, POST process are very vital for optimum peroformance., , – Scan the PC for a computer virus, , Optimizing the hard disk: Windows ScanDisk and Disk, Defragmenter utilities are the best tools available for, optimizing the hard disk in terms of usage and access, speeds. ScanDisk is used to check a disk for errors and, repair them or remove unrecoverable areas of the disk, from the usage tables to prevent future errors. Similarly, Disk Defragmenter organizes data file fragments into a, more optimized and logical format that provides for, faster access times and less head movement., Optimizing the Expansion cards: The best way to, optimize I/O controllers and other expansion cards is to, install them in the correct order. No harm is done even if, , – Ensure that CPU fan is spinning, – Ensure proper connections of external I/O connectors, – Reseat the expansion cards and check the power and, data cables of internal devices, – Most of the boot problems are the result of a recent, change, check out the BIOS setup configuration data, – To install any new hardware or software, visit manufacturer’s web site for any known conflict or incompatibility, – Check for any resource conflict if any new hardware or, software is installed., The forth coming lessons on Troubleshooting PC are, provided with Problem Trees for different type of problems, which a user face normally. Each Tree with a specific, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 43
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problem gives scope to analyse the areas to be suspected, or looked into for fixing the problem. This lesson includes, a Problem Tree for a PC which is Dead with no display on, monitor., PROBLEM TREE : PT- 01, Observed symptom, , : Dead, , Additional symptom, , : No display, , PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”., Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , 44, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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SAFE MODE, SURFACE SCAN TEST, , HDD, BAD SECTORS, , OS, , Discuss the Troubleshooting chart (TSC-01) and Service flow sequence (SFS-01) for the complaint “When, windows is started system runs surface test and goes to safemode” referring to exercise 2.33, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished, , 45
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PROBLEM TREE : PT- 02, Observed symptom, Additional symptom, , : Windows shows “illegal operation”, : Windows not working, , Discuss the Troubleshooting chart (TSC-02) and Service flow sequence (SFS-02) for the complaint “While, working, windows shows error - illegal operation”, Various faults discussed for the above complaint shall be applied to actual Computer given to you for, practical exercises., , Observed symptom, , PROBLEM TREE : PT- 03, : DVD drive can’t read, , Additional symptom, , :, , 46, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.16, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.17, COPA - Computer basics & Software installation, Application softwares, Objective: At the end of this lesson you shall be able to, • describe various software types., Application software, Application software is a term which is used for software, created for a specific purpose. It is generally a program, or collection of programs used by end users. It can be, called an application or simply an app., In fact all the software other than system software and, programming software are application software., Application software definition, A software which is developed to help the user to perform, specific tasks is called application software., The different types of application software include the following:, Application Software Type, , Examples, , Word processing software, , MS Word, WordPad and Notepad, , Database software, , Oracle, MS Access etc, , Spreadsheet software, , Apple Numbers, Microsoft Excel, , Multimedia software, , Real Player, Media Player, , Presentation Software, , Microsoft Power Point, Keynotes, , Enterprise Software, , Customer relationship management system, , Information Worker Software, , Documentation tools, resource management tools, , Educational Software, , Dictionaries: Encarta, BritannicaMathematical:, MATLABOthers: Google Earth, NASA World Wind, , Simulation Software, , Flight and scientific simulators, , Content Access Software, browsers, , Accessing content through media players, web, , Application Suites, , OpenOffice, Microsoft Office, , Software for Engineering and Product Development, , IDE or Integrated Development Environments, , Copyright @ NIMI Not to be Republished, , 47
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There are various different types of application software, such as licensed, sold, freeware, shareware and open, source., Application software's either need to be installed or can, run online. Application software's can also be distinguished, on the basis of usage into the following:, •, , Utility programs, , •, , Generic programs, , •, , Integrated programs, , •, , Specific software, , •, , Bespoke software, , •, , Word processing software, , 48, , •, , Desktop publishing software, , •, , Spreadsheet software, , •, , Database software, , •, , Presentation software, , •, , Internet Browsers, , •, , Email Programs, , •, , Graphic Programs (Pixel based), , •, , Graphic Programs (vector based), , •, , Communication software: Communication through, audio, video or chat based means, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.17, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.18&1.4.19, COPA - Computer basics & Software installation, Bluetooth devices, Objectives : At the end of this lesson you shall be able to, • describe the meaning of Bluetooth, • describe the method of using Bluetooth, • list the major applications of Bluetooth., Introduction:, Bluetooth is a wireless technology standard for, exchanging data over short distances (using shortwavelength UHF radio waves in the range 2.4 to 2.485, GHz) from fixed and mobile devices, and building, personal area networks (PANs). It is a standard wirereplacement communications protocol primarily designed, for low-power consumption, with a short range based on, low-cost transceiver microchips in each device., It can connect up to eight devices (items of electronic, equipment) at the same time. The chip can be plugged, into items such as computers, digital cameras, mobile, phones and faxes. Bluetooth is particularly convenient, in certain situations - for example, when transferring files, from one mobile phone to another without cables., Sending music and photos between a PC and a mobile, phone is another useful application., Because the devices use a radio (broadcast), communications system, they do not have to be in visual, line of sight of each other, however a quasi optical, wireless path must be viable., Range is power-class-dependent, but effective ranges, vary in practice varying from 10 to 100 m., The name 'Bluetooth' reflects the Scandinavian origins, of the technology. It is named after a 10th century Danish, viking, King Harald Blåtand (translating as 'Bluetooth' in, English).He united and controlled Denmark and Norway,, hence the association of uniting devices through, Bluetooth., , When devices like mobile phones, laptops, tablets etc., enable Bluetooth the Bluetooth icon is on., To establish a Bluetooth connection:, 1 Find the file you wish to send., 2 Select the option to send it via Bluetooth - your device, will search for other devices within range and display, them., 3 Scroll to the device you wish to connect with and, select it., 4 If the other device needs 'pairing', you will need to, enter a passcode - a bit like a PIN number - and make, sure it is entered on the other device., When the connection is established, the data will start to, send. You do not need worry about a clear line of sight, between devices., List of Bluetooth applications, Some of the Bluetooth applications are as follows:, Wireless control of and communication between a mobile, phone and a handsfree headset.(Refer fig. 1), , Fig 1, , To use Bluetooth, the device must be Bluetooth enabled., For this purpose a device called "Dongle"may be used., A dongle is a device that plugs into the computer to, enable it to use Bluetooth. Every manufacturer of, compatible devices will have their own instructions for, accessing Bluetooth. For detailed instructions you will, need to see the manual, but as a general guide:, To set up Bluetooth:, (Identify the blue tooth icon on devices.), 1 Turn on, or enable, Bluetooth. Ensure your device is, 'visible' and not 'hidden', so other nearby devices can, pick up the signal., 2 Give your device a name to identify it when, connecting to other compatible equipment., , Copa 118290A1, , Using Bluetooth, , • Wireless control of and communication between a, , mobile phone and a Bluetooth compatible car stereo, system., , • Wireless control of and communication with tablets, and speakers such as iPad and Android devices., , • Wireless networking between PCs in a confined space, and where little bandwidth is required., , • Wireless communication with PC input and output, , devices, the most common being the mouse,, keyboard and printer., , Copyright @ NIMI Not to be Republished, , 49
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• Transfer of files, contact details, calendar, , appointments, and reminders between devices with, OBEX(Objects exchange)., , • Replacement of previous wired RS-232 serial, , communications in test equipment, GPS receivers,, medical equipment, bar code scanners, and traffic, control devices., , Wi-Fi:, Wi-Fi is a popular wireless networking technology. WiFi stands for "wireless fidelity". The Wi-Fi was invented, by NCR corporation/AT&T in Netherlands in 1991. By, using this technology we can exchange the information, between two or more devices. Wi-Fi has been developed, for mobile computing devices, such has laptops, but it is, now extensively using for mobile applications and, consumer electronics like televisions, DVD players and, digital cameras. There should be two possibilities in, communicating with the Wi-Fi connection that may be, through access point to the client connection or client to, client connection. Wi-Fi is a one type of wireless, technology. It is commonly called as wireless LAN (local, area network). Wi-Fi allows local area networks to, operate without cable and wiring. It is making popular, choice for home and business networks. A computer's, wireless adaptor transfers the data into a radio signal, and transfers the data into antenna for users., , Fig 1, , • Wireless bridge between two Industrial Ethernet, networks., , • Wireless controllers in gaming consoles., • Personal security application on mobile phones for, prevention of theft or loss of items. The protected, item has a Bluetooth marker (e.g., a tag) that is in, constant communication with the phone. If the, connection is broken (the marker is out of range of, the phone) then an alarm is raised., , And can now generate a system within Resorts, library,, schools, colleges, campus, personal institutes, as well, as espresso stores as well as on the open public spot to, help to make the company much more lucrative as well, as interact with their own customer whenever. Wi-Fi, compatibility can make surf with stare to company using, their inspiring cable television much a smaller amount, force down., The radio signals are transmitted from antennas and, routers that signals are picked up by Wi-Fi receivers,, such has computers and cell phones that are ready with, Wi-Fi cards. Whenever the computer receives the signals, within the range of 100-150 feet for router it connect the, device immediately. The range of the Wi-Fi is depends, upon the environment, indoor or outdoor ranges. The, Wi-Fi cards will read the signals and create an internet, connection between user and network. The speed of the, device using Wi-Fi connection increases as the computer, gets closer to the main source and speed is decreases, computer gets further away., , Copa 1121802, , Copa 1121801, , Fig 2, , Working Principle:, Wi-Fi is a high speed internet connection and network, connection without use of any cables or wires. The, wireless network is operating three essential elements, that are radio signals, antenna and router. The radio, waves are keys which make the Wi-Fi networking, possible. The computers and cell phones are ready with, Wi-Fi cards. Wi-Fi compatibility has been using a new, creation to constituent within the ground connected with, community network. The actual broadcast is connected, with in sequence in fact it is completed by way of stereo, system surf as well as the worth of wires with monitor to, classification prone. Wi-Fi allows the person in order to, get access to web any place in the actual provided area., , 50, , Security:, Security is impartment element in the Wi-Fi technology., Security is our personal decision but having a wireless, connection we should pay attention to protect our private, details. We can connect easily to unsecured wireless, routers. The problem is any one is connected to, thewireless router using the data like download games,, download apps and planning terrorist activities, shirring, illegal music and movie files etc. So it is necessary to, provide security to the wireless technologies based, devices., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.18 & 1.4.19, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.4.20, COPA - Computer basics & Software installation, DVDs, CDs and burning DVDs, Objectives : At the end of this lesson you shall be able to, • describe the features of CDs & DVDS, • describe the main formats of DVDs, • describe DVD burning, • describe the features of CDs., Introduction, DVD (sometimes called as "digital video disc" or "digital, versatile disc") is a digital optical disc storage format., DVDs can be usedwith many types of players, including, PCs and standalone players., These discs are known as DVD-ROM, because data can, only be read and not written or erased. Blank recordable, DVD discs (DVD-R and DVD+R) can be recorded once, using a DVD recorder and then function as a DVD-ROM., Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM), can be recorded and erased multiple times., DVD features and formats, DVDs are used in DVD-Video consumer digital video, format and in DVD-Audio consumer digital audio format., They can also be used in a special AVCHD format (, Advanced Video Coding High Definition) often used with, AVCHD format camcorders. DVDs containing other types, of information may be referred to as DVD data discs., A typical recordable DVD can hold about 4.7 gigabytes, (GB). However, the total amount of disc space that you, can use to burn files to the disc is less than the amount, that's often listed on the disc itself. This is because the, disc capacity is calculated differently when it's used in a, computer. For example, a typical DVD-R that has a listed, disc capacity of 4.7 GB can only store about 4.37 GB of, data on the disc. DVDs offer a storage capacity of, approximately 4.7 GB. DVD discs do not deteriorate over, time and are unaffected by magnetic fields., The type of recordable disc to be used depends on a, few different factors, such as:, , • The types of recordable discs that work with the disc, burner., , • The disc drive on the computer or device will read, the disc after it is burned., , • The total size of all the files that will be burned on to, a disc., , DVD burning, The process of recording source material onto an optical, disc (CD or DVD) is called burning / writing or optical, disc authoring.Creating an optical disc usually involves, first creating a disk image with a full file system designed, for the optical disc, and then actually burning the image, to the disc. Many programs are available as bundled, applications to create the disk image and burn the files., , The speed at which a DVD can be written is expressed, as a multiplier: 16X means 16 times faster than just, playing it. Speeds upto 52X are also very common., CD or DVD formats, For burning DVDs, the two main disc formatsin use are:, , • Live File System and, • Mastered disc formats., Live File System format :, Discs that use the Live File System format are often, more convenient because you can copy selected files, immediately and as often as you want, just like you can, with a USB flash drive. This is convenient if you want to, keep a disc in your CD, DVD, or Blu ray Disc burner and, copy files whenever the need arises. In this format you, can copy and erase files over and over again. However,, the Live File System optical disc format is only readable, by Windows 7, Windows Vista, and Windows XP, systems. These discs are not blank after they're, formatted., Discs formatted in this format have the option name in, the Burn a Disc dialog box: "Like a USB flash drive.", Mastered disc formats:, If we want to create an optical disc that can be used to, transfer data files to older versions of the Windows, operating system or even to another operating system,, weneed to use the Mastered optical disc format. Also if, we want to burn music or pictures and use the disc in, regular CD, DVD, or Blu ray Disc players that can play, MP3 files and show digital pictures, we should use the, Mastered optical disc format., The Mastered format works just like burning CDs in, Windows XP. In other words, when we write the disc, we, copy a file or a group of files to the optical disc all at, once. Once this is done, the disc is closed and we cannot, copy more files to the disc nor can we delete the existing, files.Hence it is recommended not to copy files, immediately; it is a good practice to assemble the entire, collection of files that needed to be copied to the disc, and then burn them all at once., Discs formatted with the Mastered option have the option, in the Burn a Disc dialog box: "With a CD/DVD player.", There are many types of tools available to create data,, music, video and audio discs. We can also create, , Copyright @ NIMI Not to be Republished, , 51
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backups that span across multiple discs, rip music tracks, from Audio CDs and create or burn disc images in, different formats. They may also provide features like, automatic audio conversion from WAV, MP3, FLAC,, WMA files, disc copying, compressed file backup and, restore, disk erasing, VCD/SVCD support, project burning, etc.., , The following formats are part of the present day Bluray Disc specification:, , Blu - ray Discs, , 3, , Blu-ray, also known as Blu-ray Disc (BD) is the name of, a new optical disc format that is rapidly replacing DVD., The format was developed to enable recording, rewriting, and playback of high-definition video (HD), as well as, storing large amounts of data. The format offers more, than five times the storage capacity of traditional DVDs, and can hold up to 25GB on a single-layer disc and 50GB, on a dual-layer disc., , 1 BD-ROM - read-only format for distribution of HD, movies, games, software, etc., 2 BD-R - recordable format for HD video recording and, PC data storage., BD-RE - rewritable format for HD video recording, and PC data storage., , At present, a single-layer disc can hold 25GB and a duallayer disc can hold 50GB. Over 9 hours of high-definition, (HD) video on a 50GB disc. About 23 hours of standarddefinition (SD) video on a 50GB disc., , The name Blu-ray is derived from the underlying, technology, which utilizes a blue-violet laser to read and, write data. The name is a combination of "Blue" (blueviolet laser) and "Ray" (optical ray). They are referred to, as "Blu-ray" discs or BDs., , 52, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.4.20, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.21, COPA - Dos & Linux operating systems, Comand line interface with DOS, Objectives: At the end of this lesson you shall be able to, • describe the hierarchical directory system in DOS, • use dos commands to create directories and subdirectories, • use dos commands to change and list directory, • use dos commands to access specific files., Hierarchical Directory System: Hierarchy in simple, terms, is, organisation or an arrangement of entities., Entities can be anything such as objects, files, people,, ideas, or any other thing., Arrangement refers to, for example, Currency can be, arranged by denomination. Pebbles can be arranged by, their size ., There are many other ways to organize entities besides, hierarchically. But, hierarchical organization is special, because by this arrangement you can name each entity, by its relationship to other entities., In DOS, entities are the Directories in a directory system., Here, the hierarchy begins with the essential core or root, entity. For instance, in a family tree, we may consider, great-great-grand father who was the root cause of our, existence as the core entity. In DOS , this core entity is, referred to as the the root directory., As in the example considered above, if we consider, great-great-grand father as the root directory, then, greatgrand father, grand father, father are referred as sub, directories. So the directories under the root directory are, called subdirectories in DOS. These subdirectrories can, trace their paths back to the root directory., , In a family tree, say, Govinda is the son of Rajappa, who, is son of Ramappa who is son of Venkappa. Venkappa, is the head or root of the family tree for Govinda., One can create many directories from the root. The root, will then be the parent of each of these directories. You, can also create subdirectories that stem from other, subdirectories that stem from other subdirectories and so, on. These new subdirectories have a subdirectory as, their parent directory. How subdirectories are arranged, hierarchically from the root is illustrated in Fig 1. The, DOS directory system is often called a tree-structured, directory system., Three levels of subdirectories are represented in Fig 1., Regardless of the number of levels, the relationship of, the subdirectories is important. Each subdirectory, as, well as the root directory, can contain user files. Two files, can have the same file name and extension as long as the, files reside in different directories. This is because, DOS, needs to know which of two same-named files your, command specifies. For this, DOS needs the name of the, directories,starting from the root, that lead to the desired, file. This sequence of directory names leading to a file is, called a path., , The DOS hierarchical file system is called a tree-structured, file system. At the base of this tree structure is the root, directory., Fig 1, , ROOT, , a1, , LEVEL - 2, , LEVEL - 3, , B, , A, , LEVEL - 1, , a11, , a2, , a21, , D, , C, , c1, , c2, , c21, , Copyright @ NIMI Not to be Republished, , a22, 53
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A path is a chain of directory names that tell DOS how to, find a file that you want. Each directory is seperated from, the other by a ‘ \ ’ character. This ‘ \ ’ is referred to as the, DOS directory delimiter. A files full path name including, the drive specifier ( C: or D: etc.,) is the absolute indicator, of where the file is located. Typical path notation are, given below;, D:\Animals\Domestic\Pets\Dog.txt, C:\Admin\Accounts\Tours\Bata.txt, Further details of path and directory structure, will be discussed at appropriate lessons., DOS COMMANDS, 1, , MKDIR, , Makes or Creates a new Directory., , MKDIR\Drivers, Or, MD\Drivers, C:\Devices>MD \Printers, This instruction creates a subdirectory by name Printers, under the current drive C:. Note that although the, command is issued from another subdirectory named, devices, the newly created subdirectory Printers does, not get created under the directory Devices but directly, under the root C:. This may be verified by issuing DIR, command under C:\ and under C:\Devices., To create a subdirectory under the directory Devices the, instruction will be,, C:\Devices>MD Printers, Discuss the following different varieties of creating, directories:, , or, MD, , C:\Devices\Printers>MD C:\Devices\Plotters, , Syntax, MKDIR C:path\dirname, Or, , 2, , CHIDR or CD, , Changes or shows the path of the current directory., Syntax, , MD d:path\dirname, , CHIDR d: path, , Where,, C: is the disk drive for the sub directory, path\ indicates the path to the directory that will, hold the subdirectory being created., dirname is the name of the subdirectory being, creating., Switch, (None), Important Notes, – MKDIR or its short form MD makes new, subdirectories under the selected root directory., – It is possible to create as many subdirectories as, you want , but remember: DOS accepts no more, than 63 characters, including backlashes, for the path, name., – Do not create too many levels of subdirectories and, with long names., – You cannot create a directory name that is identical to, a file name in the current directory., For example, if you have a file named FLIES in the, current directory, you cannot create a subdirectory by the, name FLIES in this directory. However, if the file FLIES, is given an extension FLIES. DOC , then the names will, not conflict and you can create a subdirectory by name, FLIES., Examples, , Or, using the short form:, CD d : path, D : path are valid disk drive and directory names., Switch, (None), You have two methods for maneuvering through, the hierarchical directories with CD: (1) starting, at the root , or top, directory of the disk and, moving down, or (2) starting with the current, directory and moving in either direction., To start at the root directory of a disk, you must begin the, path with the path character (\), as in \ or B:\. When DOS, sees \ as the first character in the path, the system starts, with the root directory. Otherwise, DOS starts with the, current directory., Changing Drives: Computer will have built in memory,, the hard disk and it will also have provision to store/read, data from floppy disk, compact disk etc. Every disk is, identified by a name such as C drive, A drive, B drive etc., C drive is represented by C: and A drive is represented, by A: and so on. DOS allows to change from current or, default drive by typing the letter identification of disk, drive desired followed immediately by a colon as shown, in the example below:, C\> a:, , To create the subdirectory by name Drivers under the, current drive, the instruction will be,, 54, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished
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This command instructs to change control from C drive to, D drive., , H Hidden files, , If the disk drive is not accessed due to non availability of, floppy or any other reason, DOS will display an error, message, , A Files ready to archive - Prefix meaning “not”, , S System files, / O List be files in sorted order., sorted N By name (alphabetic), , Not ready error reading drive A, , S By size (smallest first), , Abort, Retry, Fail ?, , E By extension (alphabetic), , It is required to press either A,R or F keys, which are, defined below, , D By date & time (earliest first), G Group directories first, , A Directs DOS to abort the command that was, responsible for the error. If this option is selected, DOS will terminate the command and redisplay, prompt., , - Prefix to reverse order, C By compression ratio (smallest first), , R Directs DOS to retry the command that caused the, error. In most cases this option is selected to correct, the the problem that was causing the error. (Floppy, disk might not be inserted)., , /S, , Displays files in specified directory and all, subdirectories., , /B, , F Directs DOS to ignore the error and attempt to, continue processing. In some cases DOS will have, an error when it reads a portion of disk., , Uses bare format (no heading information or, summary)., , /L, , DOS COMMAND, DIR, , Displays a list of files and subdirectories in, a directory., , Syntax, DIR C:path/filename [/P] [/W] [/A[[:]attribs]] [/O[[:]sortord]], [/S] [/B] [/L] [/C[H]], , Where,, –, , C: is the disk drive holding the directory for, displaying list of files and subdirectories, , –, , path/ specifies directory and/or files to list., , –, , filename specifies file or list of files to display,, if file name is not specified all the files in the, directory will be listed., , –, , [/P] [/W] ......... specifies the switches for, formatting the output., , Switch, /P, , Pauses after each screenful of information and, waits to press any key. On pressing any key, another screenful or remaining information will, be displayed. Command is DIR/P, , /W, , Uses wide format of 80-column to display file, names only and information about file size,, date, and time is not displayed. Command is, DIR/W, , /A, , Displays files with specified attributes., , Uses lowercase., , / C[H] Displays file compression ratio; /CH uses host, allocation unit size., Important Notes:, – In the directory listing similar files can be listed by, using wildcards (* and ?), where (*) star and (?), question mark are called wild characters or wild cards., * can replace remaining charecters and ? can replace, any single character., – When DIR is used without parameters or switches, It, displays the disks volume label and serial number;, one directory or filename per line, including the file, size in bytes, and the date and time the file was, modified; and the total number of files listed, their, cumulative size and the free space ( in bytes), remaining on the disk., Examples, DIR *.txt, *.txt instruction will list all files having txt extension, in the specified directory., DIR ???T.*, ???T instruction will search for files having four, characters which ends with T like TEST,, REST etc. And * instructs that these files may have, any extension like .txt, .dat etc., , attribs, D Directories, R Read-only files, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.21, , Copyright @ NIMI Not to be Republished, , 55
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IT & ITES, Related Theory for Exercise 1.5.22, COPA - Dos & Linux operating systems, Methods to display the contents of a text file, Objectives: At the end of this lesson you shall be able to, • use DOS commands to display the contents of a text file, • use DOS commands to copy,rename,delete and undelete files., DOS Commands, , Examples, , TYPE Displays the contents of a text file., , 1 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt, , Syntax, , C:\COPA\DOS\PRACT_3 is the path to the file, TEST.txt and TYPE is the command to be executed, by DOS., , TYPE C:path/filename, Where,, –, , C: is the disk drive holding the file for displaying., , –, , path/ Specifies the location of file for displaying., , –, , filename specifies file to display., , Switch, , 2 C:\>TYPE C:\COPA\DOS\PRACT_3\>TEST1.txt, This results in the same output as in example1. While, working from C: (C drive) this command can be, issued with out changing the directories., 3 C:\COPA\DOS\PRACT_3>TYPE TEST1.txt | MORE, This will also result in the same output but displayed, screen page by screen page. Screen page can be, changed on press of any key. Along with MORE, another character is prefixed ‘|’ this called the piping, command, Which will route the output of TYPE, command to another command MORE and the, MORE filter outputs the information., , (none), Important notes:, – TYPE command provides a quick way to display, contents of an ASCII file with out having to use, another program. The file is stored on the disk as, ASCII (American Standard code for Information, Interchange) text. which is standard way the computer, translates binary ( ones and zeros) into letters,, numbers & symbols. If the information is not stored in, the ASCII format, on using TYPE command the, information will look like gibberish., – On issuing command DOS will look in drive specified,, moves into the path to reach the filename specified., Then it simply translates ASCII format into the, characters, numbers and symbols and displays on, the monitor. The video monitor can show 24 lines of, information only. if the file contains more than 24, lines starting lines can not be seen since the type, command simply scrolls all information on to the, screen. Scrolling can be controlled by pressing, Control + S keys together (on holding control key, press S key and release both the keys is called as, Control + S) scrolling of information will stop on the, monitor. After viewing the contents on the screen any, key can be pressed to scroll through the remaining, contents. To view the contents of the file screen page, by screen page, MORE command can also be used., which will stop the scrolling of information on the, screen exactly after a screen page and in the screen, page at 24 line a prompt message — More— is, displayed. After pressing any key another screen, page will be displayed. MORE is a filter e.g. itis a, program that manipulates the stream of standard, characters to the file to the standard output (monitor), screen page by screen page., , 56, , Renaming of file(s), RENAME, Or, , This command allows to change, the name of a file., , REN, Syntax, REN C: PATH\filename1.ex1 filename2.ex2, Where,, – C: is the disk drive holding the file for displaying., – PATH/ Specifies the location of file for displaying., – filename1.ex1 is the file to be renamed, – filename2.ex2 is the new filename, Important Notes:, – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be renamed., – A valid file name with appropriate extension is to be, given for new filename., – Wild characters are permitted in the file names by, which required group of files can be renamed., , Copyright @ NIMI Not to be Republished
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– Only file names will be changed and contents remain, same., – If attempted to change a file name to a name that, already exists in the directory., DOS prompts an error message, , Instructor shall discuss the simple switches, with at least two examples in each case ., For further details on COPY command switches, refer any tutorial or hand book on DOS, Important Notes:, , Duplicate file name or file not found, – If a invalid file name or the new name is not given,, then also DOS prompts an error message, Rules for the file names., – A File name must have 1 to 8 characters., – An optional extension of 1 to 3 characters, – A period (.) between the name and extension name,, if extension is used, – All letters from A through Z ( lower case letters are, automatically transferred to uppercase), 0 to 9, numbers and special characters & symbols $ # & @, ! ^ ( ) _ - { } ‘ ~ are permitted in the file name., , – DOS command COPY can duplicate one or more, files. In the same directory with different names or, from one directory to other directory either in the, same name or in different name., – If the drive is not specified current disk drive will be, used., – If the path is not specified current directory will be, used., – Exact file name with extension is to be given for the, file to be copied, – A valid file name with appropriate extension is to be, given for new copied filename, , – The control characters such as Esc, Del, or space bar, cannot be used in the file name., , – Wild characters are permitted in the file names by, which required group of files can be copied, , – The characters + = / [ ] : ; ? * < > : are not permitted., , – On copying, both source and target files will have, same contents., , – Each file name in a directory must be unique., Examples:, , – Copy overwrites the target file with the same name, , TEST2.txt, , – Copy will not allow to copy a file to it self that is source, and target files should not be same, , C:\COPA\DOS\PRACT_3\ is the drive and path to the, TEST2.txt file, TEST2.txt is the file name to be renamed, , – If the destination file name is not specified while, concatenation the first file name will become the, destination name. After the first file name, additional, source files must be preceded by a plus (+) sign., , CHECKED.txt is the new filename, , Example, , 1 C:\COPA\DOS\PRACT_3\>REN, CHECKED.txt, , 2 C:\COPA\DOS\PRACT_3\>REN *.pic *.jpg the pic, extension will be changed to jpg extension files., Copying files:, COPY Copies one or more files to another location., Syntax, COPY [/A | /B] source [/A | /B] [+ source [/A | /B] [+ ...]], [destination[/A | /B]] [/V] [/Y | /-Y] source specifies the file, or files to be copied. Destination specifies the directory, and/or filename for the new file(s)., Switches, /A, , Indicates an ASCII text file., , /B, , Indicates a binary file., , /V, , Verifies that new files are written correctly., , /Y, , Suppresses prompting to confirm you want to, overwrite an existing destination file., , /-Y Causes prompting to confirm you want to overwrite, an existing destination file., , 1 C:\COPA\DOS\PRACT_3\>COPY, TRIAL.txt, , TEST2.txt, , With the above command C:\COPA\DOS\PRACT_3, directory TEST2.txt file will be copied as TRIAL.txt, file in the same directory. On listing the directory both, the files will have same details and on viewing the, contents of both the file will be same. After copying, DOS prompts a message 1 file copied, 2 C:\COPA\DOS\PRACT_3\>COPY *.bmp *.pic, With the above command C:\COPA\DOS\PRACT_3, directory all files with bmp extension file will be, copied as pic extension files in the same directory., While copying DOS prompts the name of file it has, copied and after completion of copying it prompts the, number of files copied., 3 C:\COPA\DOS\PRACT_3\>COPY, C:\COPA\DOS\PRACT_4\, , *.pic, , All files with pic extension in C:\COPA\DOS\PRACT_3, directory will be copied to C:\COPA\DOS\PRACT_4, directory with same name & extension., Using *.* after the copy command will copy all files, with all extension to the destination., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 57
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Copy concatenating: Multiple file can be combined to, form a single file by use of + between the source files and, is called, as concatenation, Example 4 C:\COPA\DOS\PRACT_3\ COPY TEST2.txt, + TRIAL.txt CONCAT1.txt, With the above command TEST2.txt and TRIAL.txt will, be combined and CONCAT1.txt file will be created which, will have the contents of first two source files., Deleting file, DEL, , Deletes the files specified., , or, Erase, Syntax, DEL C:path/filename [/P], ERASE C:path/filename [/P], Where,, –, , C: is the disk drive holding the file to be deleted., , –, , path/ Specifies the location of file to be deleted., , –, , filename is the file to be deleted, , Switch, /P Prompts for confirmation before deleting the specified, file. Using the /P switch, If the /P switch is used, DEL displays the name of a file, and prompts with a message in the following format:, filename, Delete (Y/N)?, Press Y to confirm the deletion, N to cancel the deletion, and display the next filename (if a group of files are, specified), or CRTL+C to stop the DEL command., Important Notes, – If the drive is not specified current disk drive will be, used, – If the path is not specified current directory will be, used, – Exact file name with extension is to be given for the, file to be deleted, , The following command is given for deleting all the files., del *.*, DEL displays the following prompt:, All files in directory will be deleted! Are you sure (Y/N)?, Press Y and then ENTER to delete all files in the, current directory, or, press N and then ENTER to cancel the deletion., –, , Directories can not be removed with DEL command, a separate command is available for removing the, directory., , – Once the file is deleted it can not be recovered if the, memory space is occupied by a new file. If accidentally, file (s) are deleted immediately it can be recovered, by using utility command., – The space occupied by the deleted file on the disk or, diskette is freed., – Check for the typographic errors in the file names, before the press of enter key to activate delete, command, Example, 1 C:\COPA\DOS\PRACT_3\>DEL TEST2.txt, With the above command TEST2.txt file will be, deleted from the C:\COPA\DOS\PRACT_3 directory., On listing the directory TEST2,txt will not be available., 2 C:\COPA\DOS\PRACT_4\>DEL *.txt, With, the, above, command, in, the, C:\COPA\DOS\PRACT_4 directory all files with txt, extension will be deleted., 3 C:\COPA\DOS\PRACT_3\TEMP \> DEL *.*, All files with any extension in, C:\COPA\DOS\, PRACT_3\TEMP directory will be deleted., Recovering deleted files:, UNDELETE, , delete protection facility, , Syntax, UNDELETE C:path/filename [/DT | /DS | /DOS], , – Wild characters are permitted in the file names by, which required group of files can be deleted, , UNDELETE [/LIST | /ALL | /PURGE[DRIVE] | /, STATUS | /LOAD | /UNLOAD, , – On deleting, files name(s) will be removed from the, directory., , /UNLOAD | /S[DRIVE] | /T[DRIVE]-entrys ]], , – All the files in a directory can be deleted by typing the, DEL command followed by [drive:]path. Wildcard, also can be used (* and ?) to delete more than one file, at a time. However, Wildcards should be used, cautiously with the DEL command to avoid deleting, files unintentionally., , 58, , Where,, –, C: is the disk drive holding the files to be, undeleted., –, , path/ Specifies the location of file to be undeleted., , –, , filename is the file to be undeleted, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished
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Important Notes:, , Switches, /LIST, , Lists the deleted files available to be, recovered., , /ALL, , Recovers files without prompting for, confirmation., , /DOS, , Recovers files listed as deleted by, MS-DOS., , /DT, , Recovers files protected by Delete, Tracker., , /DS, , Recovers files protected by Delete, Sentry., , /LOAD, , Loads Undelete into memory for, delete protection., , /UNLOAD, , Unloads Undelete from memory., , /PURGE[drive], , Purges all files in the Delete Sentry, directory., , /STATUS, , Display the protection method in, effect for each drive., , /S[drive], , Enables Delete Sentry method of, protection., , /T[drive][-entrys], , Enables Delete Tracking method of, protection., , Once a file is deleted from disk, it may not be possible, to retrieve it. Although the UNDELETE command can, retrieve deleted files, it can do so with certainty only if, no other files have been created or changed on the disk., If a file is accidentally deleted and it is required to, keep, stop what all other activities on the computer and, immediately use the UNDELETE command to retrieve, the file., Example, 1 C:\COPA\DOS\PRACT_3\>UNDELETE TEST2.txt, With the above command TEST2.txt file will be, recovered. On listing TEST2.txt file will be available, in C:\COPA\DOS\PRACT_3 directory., 2 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE, With the above command multiple files can be, recovered. DOS will prompt for confirmation of, undeletion of each file and asks to type the first letter, of the file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen ., 3 C:\COPA\DOS\PRACT_4\TEMP\>UNDELETE /ALL, With the above command multiple files can be, recovered. DOS will not prompt for confirmation of, undeletion of each file. After undeletion and listing of, C:\COPA\DOS\PRACT_4 directory, undeleted file, names can be seen., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.22, , Copyright @ NIMI Not to be Republished, , 59
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IT & ITES, COPA - Dos & Linux Operating System, , Related Theory for Exercise 1.5.23, , Introduction to Linux operating system, Objectives: At the end of this lesson you shall be able to, • overview of linux, • define futures of linux, • explain application area of linux, • describe about kernel., Overview of Linux, , Where is Linux?, , The operating system, , One of the most noted properties of Linux is where it can, be used. Windows and OS X are predominantly found on, personal computing devices such as desktop and laptop, computers. Other operating systems, such as Symbian,, are found on small devices such as phones and PDAs,, while mainframes and supercomputers found in major, academic and corporate labs use specialized operating, systems such as AS/400 and the Cray OS., , Developers need special tools (like the compilers and, command lines found in GNU) to write applications that, can talk to the kernel. They also need tools and applications, to make it easy for outside applications to access the, kernel after the application is written and installed., This collective set of tools, combined with a kernel, is, known as the operating system. It is generally the lowest, layer of the computer's software that is accessible by the, average user. General users get to the operating system, when they access the command line., Linux provides powerful tools with which to write their, applications: developer environments, editors, and, compilers are designed to take a developer's code and, convert it to something that can access the kernel and, get tasks done., Like the kernel, the Linux operating system is also, modular. Developers can pick and choose the operating, tools to provide users and developers with a new flavor of, Linux designed to meet specific tasks., Introduction to Linux, Linux (pronounced Lih-nucks) is a UNIX-like operating, system that runs on many different computers. Although, many people might refer to Linux as the operating, system and included software, strictly speaking, Linux is, the operating system kernel, which comes with a, distribution of software., Linux was first released in 1991 by its author Linus Torvalds, at the University of Helsinki. Since then it has grown, tremendously in popularity as programmers around the, world embraced his project of building a free, operating system, adding features, and fixing problems., Linux is popular with today's generation of computer, users for the same reasons early versions of the UNIX, operating system enticed fans more than 20 years ago., Linux is portable, which means you'll find versions, running on name-brand or clone PCs, Apple Macintoshes,, Sun workstations, or Digital Equipment Corporation, Alpha-based computers. Linux also comes with source, code, so you can change or customize the software to, adapt to your needs. Finally, Linux is a great operating, system, rich in features adopted from other versions of, UNIX., 60, , Linux, which began its existence as a server OS and Has, become useful as a desktop OS, can also be used on all, of these devices. ‚ÄúFrom wristwatches to, supercomputers,‚Äù is the popular description of Linux', capabilities., The future of Linux, Linux is already successful on many different kinds of, devices, but there are also many technological areas where, Linux is moving towards, even as desktop and server, development continues to grow faster than any other, operating system today., Linux is being installed on the system BIOS of laptop and, notebook computers, which will enable users to turn their, devices on in a matter of seconds, bringing up a, streamlined Linux environment. This environment will have, Internet connectivity tools such as a web browser and an, e-mail client, allowing users to work on the Internet without, having to boot all the way into their device's, primary operating system-even if that operating system is, Windows., At the same time, Linux is showing up on mobile Internet, devices (MIDs). This includes embedded devices such as, smart phones and PDAs, as well as netbook devicessmall laptop-type machines that feature the core, functionality of their larger counterparts in a smaller, more, energy-efficient package., The growth of cloud computing is a natural fit for Linux,, which already runs many of the Internet's web servers., Linux enables cloud services such as Amazon's A3 to, work with superior capability to deliver online applications, and information to users., Related to Linux' growth in cloud computing is the, well-known success of Linux on supercomputers, both in, the high-performance computing (HPC) and high-availability, (HA) areas, where academic research in physics and, bioengineering, and firms in the financial and energy, , Copyright @ NIMI Not to be Republished
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industries need reliable and scalable computing power to, accomplish their goals., Many of the popular Web 2.0 services on the Internet,, such as Twitter, Linked In, YouTube, and Google all rely, on Linux as their operating system. As new web services, arrive in the future, Linux will increasingly be the platform, that drives these new technologies., , The kernel of the Window operating system (which few, people outside of Microsoft are allowed to look at without, Fig 1, , Current application of Linux operating systems, Today Linux has joined the desktop market. Linux, developers concentrated on networking and services in, the beginning, and office applications have been the last, barrier to be taken down. They don't like to admit that, Microsoft is ruling this market, so plenty of alternatives, have been started over the last couple of years to make, Linux an acceptable choice as a workstation, providing an, easy user interface and MS compatible office applications, like word processors, spreadsheets, presentations and, the like. On the server side, Linux is well-known as a stable, and reliable platform, providing database and trading, services for companies like Amazon, the well-known online, bookshop, US Post Office, the German army and many, others. Especially Internet providers and Internet service, providers have grown fond of Linux as firewall, proxy- and, web server, and you will find a Linux box within reach of, every UNIX system administrator who appreciates a, comfortable management station. In post offices, they are, the nerve centres that route mail and in large search engine,, clusters are used to perform internet searches. These are, only a few of the thousands of heavy-duty jobs that Linux, is performing day-to-day across the world. It is also worth, to note that modern Linux not only runs on workstations,, mid- and high-end servers, but also on "gadgets" like PDA's,, mobiles, a shipload of embedded applications and even, on experimental wristwatches. This makes Linux the only, operating system in the world covering such a wide range, of hardware., The code, Linux is also unique from other operating systems in that, it has no single owner. Torvalds still manages the, development of the Linux kernel, but commercial and, private developers contribute other software to make the, whole Linux operating system., The kernel, All operating systems have kernels, built around the, architectural metaphor that there must be a central set of, instructions to direct device hardware, surrounded by, various modular layers of functionality. The Linux kernel is, unique and flexible because it is also modular in nature., Modularity is desirable because it allows developers to, shed parts of the kernel they don't need to use. Typically, a smaller kernel is a faster kernel, because it isn't running, processes it does not need., If a device developer wants a version of Linux to run on a, cell phone, she does not need the kernel functionality that, deals with disk drives, Ethernet devices, or big monitor, screens. She can pull out those pieces (and others), leaving, just the optimized kernel to use for the phone., , paying for the privilege) is a solidly connected piece of, code, unable to be easily broken up into pieces. It is difficult, (if not impossible) to pare down the Windows kernel to fit, on a phone., This modularity is significant to the success of Linux. The, ability to scale down (or up) to meet the needs of a specific, platform is a big advantage over other operating systems, constrained to just a few possible platforms., Modularity also effects stability and security as well. If, one piece of the kernel code happens to fail, the rest of, the kernel will not crash. Similarly, an illicit attack on one, part of the kernel (or the rest of the operating system), might hamper that part of the code, but should not, compromise the security of the whole device., The environments, The windows, menus, and dialog boxes most people think, of as part of the operating system are actually separate, layers, known as the windowing system and the desktop, environment., These layers provide the human-oriented graphical user, interface (GUI) that enables users to easily work with, applications in the operating system and third-party, applications to be installed on the operating system., In Linux, there a lot of choices for which windowing, system and desktop environment can be used,, something that Linux allows users to decide. This cannot, be done in Windows and it's difficult to do in OS X., Like the operating system and kernel, there are tools and, code libraries available that let application developers to, more readily work with these environments (e.g., gtk+ for, GNOME, Qt for KDE)., The applications, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished, , 61
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Operating systems have two kinds of applications: those, that are essential components of the operating system, itself, and those that users will install later. Closed, operating systems, like Windows and OS X, will not let, users (or developers) pick and choose the essential, component applications they can use. Windows, developers must use Microsoft's compiler, windowing, system, and so on., Linux application developers have a larger set of choices, to develop their application. This allows more flexibility to, build an application, but it does mean a developer will, need to decide which Linux components to use., The distributions, A Linux distribution is a collection of (usually open source), software on top of a Linux kernel. A distribution (or short,, distro) can bundle server software, system management, tools, documentation and many desktop applications in a, central secure software repository. A distro aims to, provide a common look and feel, secure and easy, software management and often a specific operational, purpose., Let's take a look at some popular distributions., Red hat, Red Hat is a billion dollar commercial Linux company that, puts a lot of effort in developing Linux. They have hundreds, of Linux specialists and are known for their excellent, support. They give their products (Red Hat, Enterprise Linux and Fedora) away for free. While Red, , 62, , Hat Enterprise Linux (RHEL) is well tested before release, and supported for up to seven years after release,, Fedora is a distro with faster updates but without, support., Ubuntu, Canonical started sending out free compact discs with, Ubuntu Linux in 2004 and quickly became popular for home, users (many switching from Microsoft Windows). Canonical, wants Ubuntu to be an easy to use graphical Linux desktop, without need to ever see a command line. Of course they, also want to make a profit by selling support for Ubuntu., Debian, There is no company behind Debian. Instead there are, thousands of well organised developers that elect a Debian, Project Leader every two years. Debian is seen as one of, the most stable Linux distributions. It is also the basis of, every release of Ubuntu. Debian comes in three versions:, stable, testing and unstable. Every Debian release is, named after a character in the movie Toy Story., Other, Distributions like Cent OS, Oracle Enterprise Linux and, Scientific Linux are based on Red Hat Enterprise Linux, and share many of the same principles, directories and, system administration techniques. Linux Mint, Edubuntu, and many other ubuntu named distributions are based on, Ubuntu and thus share a lot with Debian. There are, hundreds of other Linux distributions., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.23, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.5.24 - 1.5.26, COPA - Dos & Linux Operating System, Handling commands and various editors, Objectives: At the end of this lesson you shall be able to, • know about terminal, • explain the command shell, • list out the directory layout of linux, • define the linux commands, • list out the special characters of linux OS, • explain various editors in linux OS., Starting up a terminal, , Some of the most popular shells are:, , To access the shell we will use a shell-like application,, also called a terminal emulator. There is a huge number, of good terminal applications out there, including the, default ones in GNOME or KDE, or Yakuake, Guake, rxvt, and so on. For now let's just stick with the default that, , • bash - the Bourne-Again Shell, the default shell on, most Linux systems., , • sh - the Bourne Shell, an older shell which is not so, widely used anymore., , Fig 1, , comes with your system. If you're using GNOME you can, access the terminal by going to Applications ->, Accessories -> Terminal or pressing Alt+F2 and typing, gnome-terminal in the run box that appears, followed by, Enter. If you're running KDE you can type instead, console after pressing Alt+F2., Depending on the distribution, the prompt may look something like user@host$. The first part before the ampersand is the login username, and the other one is the, hostname of the computer., Command shell, , • csh - the ‘C’ Shell, which accepts a syntax which, resembles the ‘C’ programming language., , • tcsh - an improved version of the ‘C’ Shell., • ksh - the Korn Shell, initially developed in the early, 1980’s., , • dash - Debian Almquist Shell, a shell created by the, Debian distribution., , Listing of shells available in the system, $ cat /etc/shells/, , A shell is a command interpreter which allows you to, interact with the computer. The way things work is pretty, simple: you type in commands, the shell interprets them,, performs the tasks it was asked to do, and finally it sends, the results to the standard output, which is usually the, screen., This is a list of files inside the root directory. The root, directory is the first location in the file system tree, hierarchy, and it is represented by the slash, character : /., , The above command will display the following output as, on Fig 2., In this tutorial we will focus on Bash, since it is the most, widely used and also one of the most powerful shells out, there. Bash is a modern implementation of the older, Bourne Shell (sh), developed by the GNU project, which, provides a huge amount of tools and which, together with, the Linux kernel, desktop environments like GNOME or, KDE and applications which run on top of them, comprise the whole Linux platform. On a Debian or Ubuntu, distribution, the default shell used by the system is specified in the file /etc/passwd (default being Bash)., 63, , Copyright @ NIMI Not to be Republished
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Fig 2, , How to display default shell in the system, Type the following command in the terminal, $ echo $SHELL, , And press Enter key. The default shell will be displayed, as on Fig 3., , Fig 3, , 64, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The Linux directory layout, Directory, , /bin, /boot, /dev, /etc, /home, /lib, /proc, /root, /sbin, /tmp, /usr, /usr/bin, /usr/include, /usr/lib, /usr/local, , /usr/sbin, /usr/share, /usr/src, /usr/X11R6, /var, , Description, The nameless base of the file system. All other directories, files, drives,, and devices are attached to this root. Commonly (but incorrectly), referred to as the “slash” or “/” directory. The “/” is just a directory, separator, not a directory itself., Essential command binaries (programs) are stored here (bash, ls,, mount, tar, etc.), Static files of the boot loader, Device files. In Linux, hardware devices are accessed just like other, files, and they are kept under this directory., Host-specific system configuration files., Location of users' personal home directories (e.g. /home/Susan)., Essential shared libraries and kernel modules., Process information pseudo-file system. An interface to kernel data, structures, The root (super user) home directory., Essential system binaries (fdisk, fsck, init, etc)., Temporary files. All users have permission to place temporary files here., The base directory for most shareable, read-only data (programs,, libraries, documentation, and much more)., Most user programs are kept here (cc, find, du, etc.)., Header files for compiling C programs., Libraries for most binary programs, “Locally” installed files. This directory only really matters in, environments where files are stored on the network. Locally-installed, files go in /usr/local/bin, /usr/local/lib, etc.). Also often used for, Software packages installed from source, or software not officially, shipped with the distribution., Non-vital system binaries (lpd, useradd, etc.), Architecture-independent data (icons, backgrounds, documentation,, terminfo, man pages, etc.)., Program source code. E.g. The Linux Kernel, source RPMs, etc., The X Window System, Variable data: mail and printer spools, log files, lock files, etc., , What are Linux commands?, Linux commands are executable binary files which can, be ran to perform certain tasks, like for example listing, the files in a directory running an entire graphical application. Examples of frequently used commands are ls,, cd, pwd, date or cat. With the exception of executable, files, there is also a category called shell built-ins, which, are commands provided by the shell itself (Bash in our, case). We'll deal with those later., The general form of a Linux command is:, command options(s) filename(s), Which specifies a command, followed by one or more, parameters, and optionally one or more files to apply it, on. For example:, $ echo -e 'Hello, world!\n', , Will output the text 'Hello, world!' followed by a newline, character. The -e parameter (also called argument, or, switch in this case) tells the echo command to interpret, escaped characters, like the trailing \n, which will add a, newline after the text inside the single quotes. Ignore the, leading dollar sign, it just signifies the shell prompt., A command may or may not have arguments. An argument can be an option or a filename., Special characters in linux operating system, it is important to know that there are many symbols and, characters that the shell interprets in special ways. This, means that certain typed characters: a) cannot be used, in certain situations, b) may be used to perform special, operations, or, c) must be "escaped" if you want to use, them in a normal way., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 65
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Character, , \, , Escape character. If you want to reference a special character, you must, “escape” it with a backslash first., Example: touch /tmp/filename\*, , /, , Directory separator, used to separate a string of directory names., Example: /usr/src/linux, , ., , Current directory. Can also “hide” files when it is the first character in a, filename., , .., , Parent directory, , ~, , User's home directory, , *, , Represents 0 or more characters in a filename, or by itself, all files in a, directory., Example: pic*2002 can represent the files pic2002, picJanuary2002,, picFeb292002, etc., , ?, , Represents a single character in a filename., Example: hello?.txt can represent hello1.txt, helloz.txt, but not, hello22.txt, , [], , Can be used to represent a range of values, e.g. [0-9], [A-Z], etc., Example: hello[0-2].txt represents the names hello0.txt,, hello1.txt, and hello2.txt, , |, , “Pipe”. Redirect the output of one command into another command., Example: ls | more, , >, , Redirect output of a command into a new file. If the file already exists,, over-write it., Example: ls > myfiles.txt, , >>, , 66, , Description, , Redirect the output of a command onto the end of an existing file., Example: echo .Mary 555-1234. >> phonenumbers.txt, , <, , Redirect a file as input to a program., Example: more < phonenumbers.txt, , ;, , Command separator. Allows you to execute multiple commands on a single, line., Example: cd /var/log ; less messages, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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The cd command, The cd command is used to change the current directory, (i.e., the directory in which the user is currently working), in Linux and other Unix-like operating systems. It is similar, to the CD and CHDIR commands in MS-DOS., cd's syntax is, cd [option] [directory], The items in square brackets are optional. When used, without specifying any directory name, cd returns the user, to the previous current directory. This provides a convenient, means of toggling between two directories., When a directory name is provided, cd changes the current, directory to it. The name can be expressed as an absolute, pathname (i.e., location relative to theroot directory) or as, a local pathname (i.e., location relative to the current, directory). It is usually more convenient to use a local, pathname when changing to a subdirectory of the current, directory., As an example, the following would change the current, directory, regardless of where it is on the system (because, it is an absolute path), to the root directory (which is, represented by a forward slash):, cd /, Likewise, the following would change the current directory,, regardless of its location, to the /usr/sbin directory (which, contains non-vital system utilities that are used by the, system administrator):, cd /usr/sbin, If a user currently in the directory /usr/local/share/man/, desired to change to the directory /usr/local/share/man/, man2, which is a subdirectory of the current directory, it, would be possible to change by using the absolute, pathname, i.e.,, cd /usr/local/share/man/man2, However, it would clearly be much less tedious to use the, relative pathname, i.e.,, cd man2, On Unix-like operating systems the current directory is, represented by a singledot and its parent directory (i.e.,, the directory that contains it) is represented by two, consecutive dots. Thus, it is possible (and often convenient), to change to the parent of the current directory by using, the following:, cd .., Another convenient feature of cd is the ability for any user, to return directly to its home directory by merely using a, tilde as the argument. A home directory, also called a, login directory, is the directory on a Unix-like operating, system that serves as the repository for a user's personal, files, directories and programs. It is also the directory that, a user is first in after logging into the system. A tilde is a, short, wavy, horizontal line character that represents the, , home directory of the current user. That is, any user can, return immediately to its home directory by typing the, following and then pressing the Enter key:, cd ~, This is easier than typing the full name of the user's home, directory, for instance, /home/josephine in the case of a, user named josephine. (And it is just one of the numerous, shortcuts that help make the command line on Unix-like, operating systems so easy to use.), When followed by a space and then a hyphen, cd both, returns the user to the previous current directory and, reports on a new line the absolute pathname of that, directory. This can further enhance the already convenient, toggling capability of cd. Toggling is particularly convenient, when at least one of the two directories has a long absolute, pathname, such as /usr/local/share/man/man2., cd has only two options, and neither of them are, commonly used. The -P option instructs cd to use the, physical directory structure instead of following symbolic, links. The -L option forces symbolic links to be followed., The pwd command, The pwd command reports the full path to the current, directory., The current directory is the directory in which a user is, currently operating while using a command line interface., A command line interface is an all-text display mode and, it is provided via a console (i.e., a display mode in which, the entire screen is text only) or via a terminal window, (i.e., a text-only window in a GUI)., The full path, also called an absolute path, to a directory, or file is the complete hierarchy of directories from the, root directory to and including that directory or file. The, root directory, which is designated by a forward slash (/),, is the base directory on the filesystem (i.e., hierarchy of, directories), and it contains all other directories,, subdirectories and files on the system. Thus, the full path, for any directory or file always begins with a forward slash., pwd is one of the most basic commands in Linux and, other Unix-like operating systems, along with ls, which is, used to list the contents of the current directory, andcd,, which is used to change the current directory., pwd's syntax is, pwd [option], Unlike most commands, pwd is almost always used just, by itself, i.e.,, Pwd, That is, it is rarely used with its options and never used, with arguments (i.e., file names or other information, provided as inputs). Anything that is typed on the same, line after pwd, with the exception of an option, is ignored,, and no error messages are returned., As an example, if a user with the username janis is in its, home directory, then the above command would typically, return /home/janis/ (because, by default, all home, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 67
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directories are located in the directory /home). Likewise,, if a user were currently working in directory /usr/share/, config (which contains a number of programconfiguration, files), then the same command would return /usr/share/, config., pwd is useful for confirming that the current directory has, actually been changed to what the user intended after, using cd. For example, after issuing the cd command to, change the current directory from /home/janis to /usr/share/, config, pwd could be used for confirmation; that is, the, following sequence of commands would be issued:, cd /usr/share/config/, pwd, The standard version of pwd has a mere two options, both, of which are employed only infrequently. The --help option, is used as follows:, pwd --help, This option displays information about pwd, of which there, is very little because it is such a simple command (i.e., it, only has two options and accepts no arguments)., The other option is --version, which displays the version, number, i.e.,, pwd --version, Although it is often thought of as standing for present, working directory, pwd is actually an acronym for print, working directory. The word print is traditional, UNIXterminology for write or display, and it originated when, computer output was typically printed on paper by default, because CRT (cathode ray tube) display monitors were, not yet widely available., The echo command, echo is a built-in command in the bash and C shells that, writes its arguments to standard output., A shell is a program that provides the command line (i.e.,, the all-text display user interface) on Linux and other Unixlike operating systems. It also executes (i.e., runs), commands that are typed into it and displays the results., bash is the default shell on Linux., A command is an instruction telling a computer to do, something. An argument is input data for a command., Standard output is the display screen by default, but it, can be redirected to a file, printer, etc., The syntax for echo is, $ echo $USER, $ echo "Hello world", The items in square brackets are optional. A string is any, finite sequence of characters (i.e., letters, numerals,, symbols and punctuation marks)., When used without any options or strings, echo returns a, blank line on the display screen followed by the command, prompt on the subsequent line. This is because pressing, the ENTER key is a signal to the system to start a new, 68, , line, and thus echo repeats this signal., When one or more strings are provided as arguments,, echo by default repeats those stings on the screen. Thus,, for example, typing in the following and pressing the ENTER, key would cause echo to repeat the phrase This is a pen., on the screen:, echo This is a pen., It is not necessary to surround the strings with quotes, as, it does not affect what is written on the screen. If quotes, (either single or double) are used, they are not repeated, on the screen., Fortunately, echo can do more than merely repeat verbatim, what follows it. That is, it can also show the value of a, particular variable if the name of the variable is preceded, directly (i.e., with no intervening spaces) by the dollar, character ($), which tells the shell to substitute the value, of the variable for its name., For example, a variable named x can be created and its, value set to 5 with the following command:, x=5, The value of x can subsequently be recalled by the following:, echo The number is $x., Echo is particularly useful for showing the values of, environmental variables, which tell the shell how to behave, as a user works at the command line or in scripts(short, programs)., For example, to see the value of HOME, the environmental, value that shows the current user's home directory, the, following would be used:, echo $HOME, Likewise, echo can be used to show a user's PATH, environmental variable, which contains a colon-separated, list of the directories that the system searches to find the, executable program corresponding to a command issued, by the user:, echo $PATH, echo, by default, follows any output with a newline, character. This is a non-printing (i.e., invisible) character, that represents the end of one line of text and the start of, the next. It is represented by \n in Unix-like operating, systems. The result is that the subsequent command, prompt begins on a new line rather than on the same line, as the output returned by echo., The -e option is used to enable echo's interpretation of, additional instances of the newline character as well as, the interpretation of other special characters, such as a, horizontal tab, which is represented by \t. Thus, for, example, the following would produce a formatted output:, echo -e "\n Projects: \n\n\tplan \n\tcode \n\ttest\n", (The above command should be written on a single line,, although it may render as two lines on smaller display, screens.) The -n option can be used to stop echo from, adding the newline to output., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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By making use of output redirection, echo provides a very, simple way of creating a new file that contains text. This, is accomplished by typing echo followed by the desired, text, the output redirection operator (which is a rightward, pointing angle bracket) and finally the name of the new, file. The file can likewise be formatted by using special, characters. Thus, for example, the formatted output from, the above example could be used to create a new file, called project1:, , Date command, , echo -e "\n Project1: \n\n\tplan \n\twrite \n\ttest\n" >, project1, , 01:13:14, , The contents of the new file, including any formatting, can, be verified by using a command such as cat or less, i.e.,, , Display current time and date., $ date, Fri Jul 6 01:07:09 IST 2012, If you are interested only in time, you can use 'date +%T', (in hh:mm:ss):, $ date +%T, tty command, Displays current terminal., $ tty, , less project1, echo can likewise be a convenient way of appending text, to the end of a file by using it together with the the append, operator, which is represented by two consecutive rightward, pointing angle brackets. However, there is always the risk, of accidentally using a single bracket instead of two,, thereby overwriting all of the contents of the file, and thus,, this feature is best reserved for use in scripts., echo can also be used with pattern matching, such as the, wildcard character, which is represented by the star, character. For example, the following would return the, phrase The gif files are followed by the names of all the .gif, image files in the current directory:, echo -e The gif files are *.gif, , /dev/pts/0, whoami command, This command reveals the current logged in user., $ whoami, raghu, id command, This command prints user and groups (UID and GID) of, current user., $ id, uid=1000(raghu) gid=1000(raghu), groups = 1000 (raghu), 4(adm), 20(dialout), 24(cdrom),, 46(plugdev), 112(lpadmin), 120(admin),122(sambashare), , The cal command, Displays calendar of current month., , By default information about current user is displayed. If, another username is provided as an argument, information, about that user will be printed:, , $ cal, July 2012, , $ id root, , Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , Clear command, , 15, , 16, , 17, , 18, , 19, , 20, , 21, , This command clears the screen., , 22, , 23, , 24, , 25, , 26, , 27, , 28, , Getting help command, , 29, , 30, , 31, , 'cal ' will display calendar for specified month and year., $ cal 08 1991, August 1991, Su, , Mo, , Tu, , We, , Th, , Fr, , Sa, , 1, , 2, , 3, , uid=0(root) gid=0(root) groups=0(root), , For all its advantages, a big disadvantage of command, line is that there are a lot of commands and even more are, their options and usage. But nobody can remember all, commands. There are some smarter ways of using, command line. Linux provides us with several such, resources discussed here:, --help option, With almost every command, '--help' option shows usage, summary for that command., , 4, , 5, , 6, , 7, , 8, , 9, , 10, , 11, , 12, , 13, , 14, , 15, , 16, , 17, , $ date --help, , 18, , 19, , 20, , 21, , 22, , 23, , 24, , Usage: date [OPTION]... [+FORMAT], , 25, , 26, , 27, , 28, , 29, , 30, , 31, , or: date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]], Display the current time in the given FORMAT, or set the, system date., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 69
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The whatis command, , $ info date, , The whatis command provides very brief descriptions of, command line programs (i.e., all-text mode programs) and, other topics related to Linux and other Unix-like operating, systems., It accomplishes this by searching the short descriptions, in the whatis database for each keyword provided to it as, an argument (i.e., input data). This database contains just, the title, section number and description from the NAME, section of each page in the man manual that is built into, most Unix-like systems., The syntax for whatis is:, whatis keyword(s), For example, the following provides a single line summary, of the headcommand (which by default displays the first, ten lines of each file that is provided to it as an argument):, whatis head, whatis can be used to simultaneously search for information, about multiple topics. For example, the following would, provide information about both head and tail (which by, default reads the final ten lines of files):, whatis head tail, The output of whatis is limited by the fact that it provides, only a single line for each keyword found in the database;, thus it supplies incomplete information about even, moderately complex commands. For example, the, following use of whatis to obtain information about the cat, command generates the output "concatenate files and print, on the standard output":, whatis cat, However, this omits some important information about cat,, particularly the facts that it is very convenient to use for, reading files and that it is also used to create and write to, files., whatis is similar to the apropos command. However,, apropos is more powerful in that its arguments are not, limited to complete words but can also be strings (i.e.,, any finite sequences of characters) which comprise parts, of words. Both commands are unusual in that they have, no options., The man command (which is used to read the built-in, manual pages), when used with its -f option, produces the, same output as whatis. Thus, for example,, man -f cat, is equivalent to, whatis cat, Info pages, , Word processors in the Linux environment, Text editors are used by many different types of people., Casual users, writers, programmers, and system, administrators will all use a text editor at one time or another, in Linux., Use of text editor, A text editor is just like a word processor without a lot of, features. All operating systems come with a basic text, editor. Linux comes with several. The main use of a text, editor is for writing something in plain text with no formatting, so that another program can read it. Based on the, information it gets from that file, the program will run one, way or another., vi Editor, "vi" (pronounced "vee eye") is a text editor with a, deceptively simple appearance that belies its great power, and efficiency. New users soon realize that there is far, more to this little program than meets the eye., vi, or one of its clones, is found in almost every version of, Linux and Unix, and, in fact, it is the only editor that is, available in virtually every Unix installation., History of vi, The vi editor was developed starting around 1976 by Bill, Joy, who was then a graduate student at the University of, California at Berkeley. Joy later went on to help found Sun, Microsystems and became its Chief Scientist., "ed" was the original Unix text editor. Like other early text, editors, it was line oriented and used from dumb printing, terminals. Joy first developed "ex" as an improved line, editor that supported a superset of ed commands. He then, developed vi as a "visual interface" to ex. That is, it allows, text to be viewed on a full screen rather than only one line, at a time. vi takes its name from this fact., vi remains very popular today in spite of the development, and widespread availability of GUI (graphical user interface), mode text editors which are far more intuitive and much, easier for beginners to use than text-mode text editors, such as vi. GUI-mode text editors include gedit and Emacs,, both, of, which, have, become, very, common on Linux and other Unixes today., Features of vi, , • It is present in almost every Linux Unix system, even, the most minimal., , • It is very small. In fact, some versions have a total, , code size of less than 100KB. This makes it easy to, include vi on even the tiniest versions of Linux, such as, those in embedded systems and those that run from a, single floppy disk., , Info documents are sometimes more elaborated than man, pages. But for some commands, info pages are just the, • It is typist-friendly, at least once you get used to it. For, same as man pages. These are like web pages. Internal, example, the commands are very short, usually just a, links are present within the info pages. These links are, few keystrokes. And because vi does not use the, called nodes. info pages can be navigated from one page, mouse, there is never any need to remove one's hands, to another through these nodes., 70, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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from the keyboard. This can speed up editing, substantially., , changes, hit ESC, type :q! and then press ENTER. This, is sometimes referred to as a "forced quit.", , • It is very powerful, as just a few very short commands, , vi works with a buffer (a block of memory in the RAM, chips). When you open an existing file, vi copies that file, from the hard disk (or floppy, CDROM, etc.) to a buffer. All, changes that you make to a file are initially made only to, the copy in the buffer, and they are only made to the file, itself when you "save" your changes. "Saving" a file means, writing (i.e., transferring) the contents of the buffer to the, hard disk (or floppy disk)., , can make sweeping changes to large documents. In, fact, vi is more powerful than most of its users realize,, and few of them know more than just fraction of all the, commands., , Opening and closing file, vi can be used both when your system is in text mode, (the entire screen is devoted to text and there are no, images) and when your system is in GUI mode (the screen, contains windows, images and menus). When it is in GUI, mode (usually KDE or Gnome), vi runs in a terminal window., A terminal window is a text-only window, and it can usually, be opened by clicking on an icon (small image) of a, computer screen., (In the case of Red Hat Linux, the terminal window can be, opened by clicking on the icon of a red hat in the lower left, hand corner of the screen, opening the System Tools menu, and then selecting Terminal from that menu. It can be, convenient to add the icon for the terminal window to the, launcher panel along the bottom of the screen, if it is not, already there.), There are at least two ways to use vi to simultaneously, create and open a new file. One is by just typing vi at the, command line, like this:, vi, This creates an empty file that will not have a name until, you save its contents to disk (i.e., transfer the text you, typed into it to your hard disk, floppy disk, etc. for long, term storage)., A second way to open a new file is by typing vi followed by, the name of the file to be created, for example:, vi apple, This creates a new file named "apple" in the current, directory (the directory or folder which is currently open, on your all-text screen or your terminal window)., If you want, it could create the same file with an extension, such as ".txt" added to the end of the file name. In Linux, this is merely a matter of convenience (or habit), and it, generally makes no real difference for the file because it, remains a plain text file in either case. For example:, vi apple.txt, To close a file to which no changes have been made, hit, ESC (the Esc key, which is located in the upper left hand, corner of the keyboard), then type :q (a colon followed by, a lower case "q") and finally press ENTER. (The term "hit", is used here instead of "press" to emphasize that it is not, necessary to keep the ESC key held down but just to, press it momentarily.), To close a file to which changes have been made (such as, text having been added or removed) without saving the, , Likewise when you open a new file. All text you enter (and, subsequent edits you make to it) exists only in the buffer, until you save the file to disk., To save the changes that have been made to a file, hit, ESC, type :qw and then press ENTER. The "w" stands for, "write." An alternative, and perhaps easier, way to save a, file and quit at the same time is to hit ESC and then type, ZZ (two capital Z's in succession)., After you have created a new text file and closed it, you, might want to confirm that nothing went wrong and that, the file actually exists. Probably the simplest way to do, this is to use the standard Unix ls command, which, displays a list of all of the files in the current directory., Entering text, vi has two basic modes of operation: command mode and, text insert mode. How to switch back and forth, between them is probably the most confusing thing about, vi for beginners. But it is actually very simple, and once, you get used to it you might also find it quite efficient., Command mode is the default mode when a file (existing, or new) is opened. (This is the opposite of most text and, word processors and therefore may seem counter-intuitive.), Because every file opens initially in command mode, you, can not immediately begin typing text. That is, everything, that is typed on the keyboard is interpreted by vi to be a, command., Examples of the many types of commands can perform, on a file while in command modes are:-, , • Switching to text insert mode., • Moving the cursor around the file., • Deleting characters or lines., • Transposing characters., • Changing case., • Appending the contents of the file to another (closed), file., , • Setting vi options., • Saving the file to disk., • Closing the file and quitting vi., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 71
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The other mode, text insert mode, is also referred to as, simply "insert mode" or "input mode." It is used for entering, text into the buffer memory (and simultaneously onto the, screen). In this mode everything that is typed on the, keyboard is added to the text and does not become a, command (although you can perform some command, operations in text mode with vi clones)., , There will be times when it need to place a character to, the right of the character under the cursor. This is, particularly useful when the cursor is over the last character, in a line and you want to append the line. To do this,, simply use the a (lower case "a," which stands for "append"), command instead of the i command to switch from, command mode into insert mode., , The most common way to switch from command mode to, the input mode is to use the i (which stands for "insert" or, "input") command. This is accomplished by simply typing, the letter i while in command mode. Now you are ready to, start typing text., , After it have saved a file that have created or modified, using vi, might want to verify that its contents are really, what you had intended. One way to do this is to use cat,, the Unix concatenation utility. (No, this has no relationship, to the popular domesticated animal whose name has the, same spelling). For example, type:, , Unlike word processors and even most word editors, there, is no automatic word wrap in the traditional version of vi, (although you will notice it in some clones). New lines are, started by pressing ENTER., When finished typing text or need to perform some other, operation such as moving to a different position in the text, or deleting some of it, hit ESC in order to return to the, command mode., Once you have typed some text, you can use the four, basic commands for moving the cursor around the text., These commands enable you to go to any desired location, in order to modify the text, including making insertions, and deletions. The four basic cursor positioning commands, are:, h move cursor one character to left, j move cursor one line down, k move cursor one line up, l move cursor one character to right, Each of these commands can be either used by itself or, modified by typing an integer in front of it to indicate the, number of characters or lines to move. For example, typing, (in command mode, of course), 3j - will move the cursor down three lines. Or typing 2h will, move it two characters to the left., These commands can be repeated by holding the key, down. If attempting an impossible movement, such as, pressing k when the cursor is on the top line, the screen, might flash or a beeping sound might be made (depending, on how your computer is set up)., The cursor can be moved directly to any desired line by, using the G command preceded by the line number. For, example, typing, 5G - moves the cursor to the fifth line from the top of the, text. Just typing G without any number moves the cursor, to the final line of text., When you switch from command mode to input mode, with the i command and then start typing text, each, character you type is placed to the left of the character, covered by the cursor. This causes the character covered, by the cursor as well as everything to its right to be shifted, to the right., 72, , cat /home/john/fruit/lemon, Editing Text, vi offers a rich assortment of commands for editing text., Among the most basic are those used for deleting or, erasing., The x (lower case "x") command deletes the character, immediately under (i,e., covered by) the cursor. To delete, any desired character, just switch to the command mode, (if you are not already there) and then use an appropriate, combination of the h, j, k and l commands (of course, one, at a time) to move the cursor to that character. Then type, x and the character is deleted., By pressing x continuously instead of just hitting it once,, the cursor continuously moves to the right and each, character under it is successively deleted., The X (upper case "X") command is similar except that it, deletes the character to the left of the cursor rather than, the character under it., There are several additional commands for deleting text., The D (upper case "D") command removes the text on the, current line from the character under the cursor to the end, of the line., The d (lower case "d") command is very flexible because, it can be modified to delete any number of characters,, words or lines. Typing d by itself will not do anything, but, typing dw causes the character the cursor is resting on, and the remaining characters to the right of it in the same, word to be deleted. (The "w" stands for "word."), Typing 2dw causes the character under the cursor, the, remaining characters to the right of it in the same word, and all of the characters in the next word to be deleted., For example, typing 2dw with the cursor on the "a" of the, string "pineapple plantation" causes the string "apple, plantation" to be deleted., As another example, typing 3dw with the cursor on the "j", of the string "the bluejay flew south" causes the string, "jay flew south" to be deleted. That is, "jay" and two words, to the right of it are deleted., Deleting an entire line can be accomplished with the dd, command. This command can also be used to delete, multiple lines by preceding it with an integer representing, the number of lines to be removed. For example, typing, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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2dd will delete two consecutive lines beginning with the, current line., , lines can be transposed with the ddp command by placing, the cursor on the upper line and typing ddp., , With some terminals, deletion of a line causes it to be, replaced on the screen with an "@" character. This, character merely represents an empty line and is not, inserted into the text. Its purpose is to relieve the processor, from having to redraw the screen (i.e., change the whole, screen). This character can be removed if desired by typing, r (or l on some terminals) while holding down the CTRL, key., , It is also a simple matter to change the case of a letter., When the cursor is over the desired letter, hit the "~" (tilde), key. This will change a capital letter to a small letter and, visa versa., , The change command c (lower case "c") differs from the, delete command in that it not only deletes a section of, text but also activates insert mode to allow you to type in, replacement text. After you have completed typing in the, replacement text, be sure to press ESC to return to the, command mode., As is the case with d, the c command is not used by itself, but is only used in combination with another letter after it, and an optional integer before it., For example, the command cw (which stands for "change, word") deletes the characters in the current word under, and to the right of the cursor and then switches vi to the, insert mode so that you can enter text to replace the deleted, characters. The number of new characters typed in can, be the same as, fewer or more than the number deleted., The amount of text to be changed can be increased by, preceding the command with a number. For instance, typing, 2cw will additionally remove the next word for replacement, with whatever is typed in. The space between the words is, not preserved., The d and c commands can also be modified by other, characters in addition to "w." For example they can be, used with "b," which stands for "back." Thus, typing3bd, will delete the characters to the left of the cursor in the, current word together with the two words to the left of the, current word., The cc command erases the current line, leaving it blank, and awaiting replacement text. Preceding this command, with an integer will delete that number of lines, beginning, with the current line. For example, typing 5cc will allow, you to change five consecutive lines starting with the current, line., Another change command, R, differs from the c commands, in that it does not initially delete anything. Rather, it, activates insert mode and lets you replace the characters, under the cursor one at a time with characters that you, type in., vi supports several types of transposition. Transposing the, order of two adjacent characters is easy with the xp, command. Just place the cursor on the left-most of the, two characters, type x to erase the left character and then, type p for the deleted character to be put to the right of the, cursor., Two adjacent words can be transposed with the deep, command. To use it, position the cursor in the space just, to the left of the word on the left and type deep. Two adjacent, , The J (upper case "J") command is used to join the next, line to the current line. The opposite operation, splitting a, line, is accomplished in insert mode by merely positioning, the cursor over what will be the first character of the new, line and then hitting ENTER., vi also has an undo capability. The u (lower case "u"), command is used to reverse the effects of an already issued, command that has changed the buffer, but which is not, yet written to disk. U (upper case "U") undoes all of the, changes that have been made to the current line during, your current visit to it, Searching Text, vi also has powerful search and replace capabilities. To, search the text of an open file for a specific string, (combination of characters or words), in the command, mode type a colon (:), "s," forward slash (/) and the search, string itself. What you type will appear on the bottom line, of the display screen. Finally, press ENTER, and the, matching area of the text will be highlighted, if it exists. If, the matching string is on an area of text that is not currently, displayed on the screen, the text will scroll to show that, area., The formal syntax for searching is:, :s/string, For example, suppose you want to search some text for, the string "cherry." Type the following and press ENTER:, :s/cherry, The first match for "cherry" in your text will then be, highlighted. To see if there are additional occurrences of, the same string in the text, type n, and the highlight will, switch to the next match, if one exists., The syntax for replacing one string with another string in, the current line is, :s/pattern/replace/, Here "pattern" represents the old string and "replace", represents the new string. For example, to replace each, occurrence of the word "lemon" in a line with "orange,", type:, :s/lemon/orange/, The syntax for replacing every occurrence of a string in, the entire text is similar. The only difference is the addition, of a "%" in front of the "s":, :%s/pattern/replace/, Thus repeating the previous example for the entire text, instead of just for a single line would be:, :%s/lemon/orange/, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 73
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Working with multiple files, It is easy to insert text into an open file from another file., All that is necessary is to move the cursor to the location, where you want the text inserted, then type, :r filename, where "filename" is the name of the file to insert., For example, if you want to copy the contents of the file, "peach" into the file "fruit," you would first position the, cursor to the desired line in "fruit" and then type, :r peach, Notice that this operation causes no change to the file, "peach.", , vi +3 apple, Use of the + command without any modifying number, opens a file with the cursor positioned on the last line of, text. This can save some keystrokes when you want to, open a file just to append data to the end of it. For example:, vi + apple, You have already learned several commands for switching, from command mode to insert mode, including i for, inserting to the left of the cursor position, a for inserting to, the right of the cursor position and the c commands for, changing text. A more complete list is as follows:, a, , appends after current cursor position., , A, , appends at end of current line., , c, , starts a change option., , C, , starts a change option from current position, to end of current line., , i, , inserts to the left of the cursor position., , I, , inserts at start of line., , o, , cursor moves to new, blank line below its, current position., , This allows you to edit "apple" first. After saving "apple,", typing :n calls up "pear" for editing., , O, , cursor moves to new, blank line above its, current position., , If you want to simultaneously open all files in the current, directory, just type vi * (vi + space + asterisk)., , R, , replaces characters one at a time., , Additional operations, , A simple way to obtain basic information about any file, that is currently open, including name, size and the current, line number, is to hold down CTRL and type g. This data, appears on the bottom line of the display., , You can also append text from the currently open file to, any other file. This is accomplished using the :w (colon +, "w") command followed without a space by >>. For, example, to append the contents of a currently open file, named "pear" to the file named "apple," type, :w>> apple, At times it can be convenient to open multiple files, simultaneously. This is efficiently accomplished by just, listing all of the files to be opened after the vi command., For example, to simultaneously open files about three kinds, of fruit, type:, vi apple pear orange, , As you have learned, creating and opening files in vi can, be a very simple matter. However, many combinations of, options are available that can add much power and, flexibility for these tasks, as can be seen by looking at, the full syntax for opening files:, vi [flags] [cmd] [filename], The square brackets ([ ]) around each section of arguments, (modifiers) of the command indicates that they are optional., (That is, a file can be opened by just typingvi alone or by, typing it with any combination of the three arguments. For, instance, the example of vi dog contains only the, mandatory vi and the optional third argument, which is the, name of the file to open.), , Summary of commands, The following list contains the basic commands presented, in the first eight pages of this tutorial along with occasional, examples of usage (shown in parenthesis). They are, presented in roughly the same order in which they appear, in the tutorial. (All commands that begin with a colon are, followed by ENTER.), , As only one of many possible examples of adding options, for opening files, an existing file can be opened with the, cursor appearing on any desired line instead of just on the, first line. (One situation in which this can be particularly, useful is if your file is part of a program which you are, writing and the compiler reports an error on a specific line, in that file.) This is accomplished by adding the + (plus, sign) command followed the desired line number. For, example, to open the file "apple" with the cursor located, on the third line, type:, 74, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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vi, vi *, , typed at the command line to open one or more files in the same directory, (vi tomato.txt opens a file named "tomato.txt" in the current directory), (vi parsley sage rosemary opens the three files "parsley," "sage" and, "rosemary" in the current directory), typed at the command line to open every file in the current directory, , :q, , closes (quits) a file to which no changes have been made, , :q!, , quits without saving any changes, , :w, , writes (i.e., saves) the current file to disk, , :wq, ZZ, i, h, , writes the buffer contents to disk (i.e., saves changes) and quits, same as :wq, activates text insert mode, inserting text immediately under the current, position of the cursor., moves the cursor one character to the left, (2h moves the cursor two characters to the left), , j, , moves the cursor one line down, (3j moves the cursor three lines down), , k, , moves the cursor one line up, , l, , moves the cursor one character to the right, , G, , moves the cursor to the desired line; moves the cursor to the last line of text, if not preceded by a modifying integer, (5G moves the cursor to the fifth line), , a, , switches to insert mode and allows insertion of text immediately to the right, of the cursor., , x, , deletes the character immediately under the cursor, (xxx deletes the character immediately under cursor and then deletes the, two characters to its right), , X, , deletes a single character to the left of cursor, , D, , removes the text on the current line from the character under the cursor to, the end of the line, , dw, , deletes the character immediately under the cursor and the remaining, characters to the right of it in the same word, (2dw deletes the character immediately under the cursor, the remaining, characters to the right of it in same word and all of the next word), , dd, , deletes the entire line containing the cursor, and the cursor then moves to, the next line, (2dd deletes two consecutive lines beginning with the current line), , cw, , deletes the character under the cursor and to its right in the same word and, allows new characters to be typed in to replace them, (2cw deletes the character under the cursor and to its right in the same, word and in the next word, and then allows replacement characters to be, typed in), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 75
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cc, , erases the current line and allows replacement text to be typed in, (2cc erases the current line and the next line and allows replacement text to, be typed in for both lines), , cb, , deletes the characters to the left of the cursor in the current word and allows, replacement characters to be typed in, (3cb deletes the characters to the left of the cursor in the current word, together with the two words to its left and then allows replacement text to be, typed in), , R, , activates text input mode allowing text under and to the right of the cursor to, be overwritten one character at a time, , xp, , transposes two adjacent characters, , deep, ddp, , transposes two adjacent lines, , ~, , changes case of the character under the cursor, , J, , joins the current line with the next line, , u, , reverses the effects of the most recent command that has changed the buffer, , U, , undoes all changes made to the current line during the current visit to it, , :s/, n, :s/ / /, , :%s/, //, , 76, , transposes two adjacent words, , searches the text for the first instance of a designated string, (:s/cucumber searches the text for the first instance of the string, "cucumber"), searches the text for the next instance of a designated string, replaces the first instance of a designated string, (:s/cucumber/radish/ replaces the first instance of the string "cucumber" with, the string "radish"), replaces every instance of a designated string, (:%s/cucumber/radish/ replaces every instance of the string "cucumber" with, the string "radish"), , :r, , inserts text into the currently open file from another file, (:r lettuce.txt inserts text into the currently open file from the file named, "lettuce.txt"), , :w>>, , appends the text from the currently open file into another file, (:w>> cabbage appends the text from the currently open file into the file, named "cabbage"), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
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pico editor, , offered as the default in subsequent searches., , pico is a simple text editor in the style of the pine, composer., , Blocks of text can be moved, copied or deleted with, creative use of the command for mark (Ctrl-^), delete, (Ctrl-k) and undelete (Ctrl-u). The delete command will, remove text between the "mark" and the current cursor, position, and place it in the "cut" buffer. The undelete, command effects a "paste" at the current cursor, position., , Syntax, pico [ options ] [ file ], Description, pico is a simple, display-oriented text editor based on the, pine message composer. As with pine, commands are, displayed at the bottom of the screen, and context-sensitive, help is provided. As characters are typed they are, immediately inserted into the text., Editing commands are entered using control-key, combinations. As a work-around for communications, programs that swallow certain control characters, you can, emulate a control key by pressing ESCAPE twice, followed, by the desired control character. For example, "ESC ESC, c" would be equivalent to entering a ctrl-c. The editor has, five basic features: paragraph justification, searching, block, cut/paste, a spelling checker, and a file browser., Paragraph justification (or filling) takes place in the, paragraph that contains the cursor, or, if the cursor is, between lines, in the paragraph immediately below., Paragraphs aredelimited by blank lines, or by lines, beginning with a space or tab. Unjustification can be done, immediately after justification using the control-U key, combination., String searches are not sensitive to case. A search, begins at the current cursor position and wraps around, the end of the text. The most recent search string is, To, , The spell checker examines all words in the text. It then, offers each misspelled word for correction while highlighting, it in the text. Spell checking can be cancelled at any time., Alternatively, pico will substitute for the default spell, checking routine a routine defined by the SPELL, environment variable. The replacement routine should read, standard input and write standard output., The file browser is offered as an option in the "Read File", and "Write Out" command prompts. It is intended to help, in searching for specific files and navigating directory, hierarchies. Filenames with sizes and names of directories, in the current working directory are presented for selection., The current working directory is displayed on the top line, of the display while the list of available, commands takes up the bottom two. Several basic file, manipulation functions are supported: file renaming,, copying, and deletion., Movement commands:, Depending on your system, the arrow keys or the, backspace key may not work. Instead, you can use these, commands to perform the same tasks., , Hold down Ctrl key and press, , Delete a character, , backspace, , Instead of, backspace, , Move up a line, , p, , up arrow, , Move down a line, , n, , down arrow, , Move left one space, , b, , left arrow, , Move right one space, , f, , right arrow, , Move to the end of line, , e, , end, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 77
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Some pico editor options, , ^K Cut text, , ^C Cancel allows you to stop a process at any time. If, you make a mistake, just hold down the Ctrl key and, press c., , Cut a line of text. This option allows you to cut a full line, of text. By using the uncut command and your arrow, keys, you can then paste the cut text at another location, in your document. To cut specific text in a line or to cut, several lines of text, first select the text (see Selecting, Text on the next page)., , ^G get help, Get clear and concise assistance from the Pico help, in, case something unexpected happens or you need, additional information about a command., ^X Exit, , Selecting text, To select text for cutting and pasting use the following, steps:, , Exit Pico at anytime. If made changes to a file or worked, on a new file, but you havent saved the changes, you see, this message:, , Move the cursor to the beginning of the text to select, , Save modified buffer (ANSWERING "No" WILL DESTROY, CHANGES) (y/n)?, , Use the right arrow key or hold down Ctrl and press f to, highlight text, , Answering no (press n) will close Pico and bring you back, to the prompt without saving your file., , When you have highlighted the appropriate text, hold down, the Ctrl key and press k to cut it., , Answering yes (press y) will allow you to save the file, you've been working on (see Write Out section below for, details)., , Paste the text you cut, anywhere in your document, using, UnCut Text, , ^O WriteOut, Save the file without hassles or worries. Fill in the name, of the file beside the File Name to write: prompt. If the file, already has a name, then press enter., ^T To Files option lets to save the text over a file that, exists in the directory. By choosing the To Files option,, Pico takes you to a directory Browser., ^R Read File, Insert text from another file into your current text file. This, option allows you to search through your directories for a, file that you would like to add to your text. This option is, especially handy if you've saved a document and would, like to add its content to the new file you're working on., Text from the file you select is placed on the line directly, above your cursor., At the Insert file : prompt you may either type a file name, or use the Browser options., ^T To Files option lets you import a text file directly into, the file you're currently typing. By choosing the To Files, option, Pico takes you to a directory Browser., ^Y Prev Pg, Move quickly to the previous page. Although you could, just as easily press the up arrow key several times, this, command quickly jumps your cursor up one page., ^V Next Pg, Move quickly to the next page. Although you could just, as easily press the down arrow key several times, this, command quickly jumps your cursor down one page., 78, , Hold down the Ctrl key and press ^, , ^U UnCut Text, Paste text that previously cut. if use this option to undo, an accidental cut of text or place cut text at another location, in the document. The text you cut is pasted on the line, directly above the cursor., ^C Cur Pos, Indicate the current position of the cursor, relative to the, entire document. This is a helpful option if you'd like to, check exactly where in the document. The status line, indicates the following items:, [line 8 of 18 (44%), character 109 of 254 (42%)], ^J Justify, Even out lines of text. This command is handy when, accidentally type extra spaces between words or press, the key before reaching the end of a line. The option, evens the length of text lines automatically., ^U UnJustify, UnJustify lines of text. For the messy line look you can, always select the UnJustify option., ^W Where is, Find a particular string of text quickly. This option allows, you to do a word search in your text. This option is, especially handy for longer documents. If the word you, designated at the Search: prompt is found, it places the, cursor beside it., ^T To Spell, Check for spelling errors. The spell check option allows, to correct spelling errors throughout the document. If spell, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished
Page 848 : checker finds a misspelled word or a word it doesn't, recognize (don't worry, this rarely happens), it will correct, the word. At the Edit a replacement: prompt, type in the, correct spelling of a word. However, if you don't want to, make any changes, simply press the enter key., Any words that have corrected but re-occur in the document, can be automatically replaced. At the Replace a with b?, [y]: prompt press y to replace all occurrences of the, misspelled word or n to ignore., Pine Editor, pine is a program for accessing email and newsgroups., Syntax, pine [options] [address, address], Description, pine is a screen-oriented message-handling tool. In its, default configuration, pine offers an intentionally limited, set of functions geared toward the novice user, but it also, has a growing list of optional power-user and personalpreference features. pine's basic feature set includes:, , • View, Save, Export, Delete, Print, Reply and Forward, messages., , • Compose messages in a simple editor (pico) with wordwrap and a spelling checker. Messages may be, postponed for later completion., , • Full-screen selection and management of message, folders., , • Address book to keep a list of long or frequently-used, , addresses. Personal distribution lists may be defined., Addresses may be taken into the address book from, incoming mail without retyping them., , • New mail checking and notification occurs, automatically., , • Context-sensitive help screens., pine supports MIME (Multipurpose Internet Mail, Extensions), an Internet Standard for representing, multipart and multimedia data in email. pine allows you to, save MIME objects to files, and in some cases, can also, initiate the correct program for viewing the object. It uses, the system's mailcap configuration file to determine what, program can process a particular MIME object type. pine's, message composer does not have multimedia capability, , itself, but any type of data file (including multimedia) can, be attached to a text message and sent, using MIME's encoding rules. This allows any group of, individuals with MIME-capable mail software to exchange, formatted documents, spread-sheets, image files, etc, via, Internet email., pine uses the "c-client" messaging API to access local, and remote mail folders. This library provides a variety of, low-level message-handling functions, including drivers for, a variety of different mail file formats, as well as routines, to access remote mail and news servers, using IMAP, (Internet Message Access Protocol) and NNTP (Network, News Transport Protocol). Outgoing mail is usually handed, off to the send mail program but it can optionally be posted, directly via SMTP., Examples, Pine, Launch pine., pine
[email protected], Launch pine, and immediately begin composing an email, addressed to
[email protected]., Joe editor, 'joe'- sounds like a comic strip. Actually, they are two other, text editors that I like and I think are a little easier to, manage. They're like 'vi' in that you use them to create, and edit non-formatted text, but they're a little more userfriendly. Using 'joe' 'joe' was created by Joseph Allen, so, that's why it's called Joe., The majority of joe's commands are based on the CTRL-K, keys and a third key. The most important of these is CTRLK-H which gets 'help'. Help shows the key combinations, to use with 'joe'., The most important thing about 'joe' is the logical concept, that you can just start writing if you want. Try writing, anything you want., To save it, press CTRL-K-D. To save and quit, CTRL-K-X., To quit without saving, CTRL-C, (without the K)., The feature of 'joe' is that if edit a file again, it will save the, previous file with a tilde on the end, like 'tryjoe~' That little, tilde file has saved times. 'joe' is a very good option for, writing those short text files., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.24 - 1.5.26, , Copyright @ NIMI Not to be Republished, , 79
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IT & ITES, Related Theory for Exercise 1.5.27 & 1.5.28, COPA - Linux Operating System, Managing files and directories, Objectives: At the end of this lesson you shall be able to, • define manipulating files and directories, • define basic file commands, • explain other file commands, • define additional useful commands in linux OS., Manipulating files or directories, Using Linux isn't different from any other computer, operating system. You create, delete, and move files on, your hard drive in order to organize your information and, manage how your system works or looks. This section, shows you how to do these tasks quickly and easily., Although the graphical interface for Linux, the X Window, System, may offer drag and drop or multiple selections in, order to copy or delete files, many of the commands you'll, learn here form the base of these operations. It is worth, knowing how these programs work, even if you don't use, Linux in the console mode., Working with files, In this chapter we learn how to recognise, create, remove,, copy and move files using commands like file, touch, rm,, cp, mv and rename, etc…, All files are case sensitive, Files on Linux (or any Unix) are case sensitive. This means, that FILE1 is different from, file1, and /etc/hosts is different from /etc/Hosts (the latter, one does not exist on a typical Linux computer)., The file command, The file command attempts to classify each filesystem, object (i.e., file, directory or link) that is provided to it as, an argument (i.e., input). Thus, it can usually provide, immediate information as to whether some specified, object is, for example, a GIF89a image file, a directory, a, GNU tar archive, ASCII English text, a symbolic link, an, HTML document, an empty file, bzip2 compressed data,, an ELF 32-bit LSB executable, etc., File accomplishes this by probing each object with three, types of tests until one succeeds. The first is a filesystem, test, which uses the stat system call to obtain information, from the object's inode (which contains information about, a file). A system call is a request in a Unix-like operating, system for a service performed by the kernel (i.e., the, core of the operating system)., The second test checks to see if there is a magic number,, which is a number embedded at or near the beginning of, many types of files that indicates the file format(i.e., the, type of file)., , it is plain text (i.e., composed entirely of human-readable, characters), and, if so, what type of plain text, such as, HTML (hypertext markup language) or source code (i.e.,, the original version of a program as written by a human)., In this situation, file also attempts to determine the natural, language (e.g., English, Turkish or Japanese) that is used, in the file., A simplified version of file's syntax is, file [option(s)] object_name(s), File has several options, but it is most commonly used, without any of them. For example, information about a file, named file1 that is located in the in the current directory, (i.e., the directory in which the user is currently working), could be obtained by merely typing the following and, pressing the RETURN key:, file file1, Information about the types of all of the files in the, current directory can be obtained by using the star wildcard, to represent every object in that directory as, follows:, file *, Likewise, information about all of the files in another, directory can be obtained by using that directory as an, argument and following it immediately by a forward slash, and the star wildcard. For example, the following, classifies all of the objects in the /boot directory:, file /boot/*, The square brackets wildcard can be used together with, the star wildcard to show the file types for only those, objects whose names begin with specified letters or with, a specified range of letters. For example, the following, would show only those objects in the current directory, whose names begin with letters a through g:, file [a-g]*, The -k option tells file to not stop at the first successful, test, but to keep going; this can result in the reporting of, additional information about some filesystem objects. The, -b (i.e., brief) option tells file to not prepend filenames to, output lines, which can be useful when compiling statistics, about file types. The -v option returns information about, the version of file that is installed., , In the event that the first two tests fail to determine the, type of a file, language tests are employed to determine if, 80, , Copyright @ NIMI Not to be Republished
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Creating files and directories command, mkdir command, The mkdir command is is used to create new, directories., A directory, referred to as a folder in some operating, systems, appears to the user as a container for other, directories and files. However, Unix-like operating, systemstreat directories as merely a special type of file, that contains a list of file names and their corresponding, inode numbers. Each inode number refers to an inode,, which is located in inode tables (which are kept at, strategic locations around the filesystem) and which, contains all information about a file (e.g., size,, permissions and date of creation) except its name and, the actual data that the file contains., mkdir has the following example, $ mkdir example, , mkdir -m 777 dir_4, The first digit represents the owner, the second represents, the group and the third represents other users. The number, 7 represents all three types of permission (i.e., read, write, and execute), 6 stands for read and write only, 5 stands, for read and execute, 4 is read only, 3 is write and execute,, 2 is write only, 1 is execute only and 0 is no permissions., Thus, for example, to create a new directory named dir_5, for which the owner has read and write permissions, the, group has read permission and other users have no, permissions, the following would be used:, mkdir -m 640 dir_5, , $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, directory_name is the name of any directory that the user, is asking mkdir to create. Any number of directories can, be created simultaneously., Thus, for example, the following command would create, three directories within the current directory (i.e., the, directory in which the user is currently working) with the, names dir_1, dir_2 and dir_3:, mkdir dir_1 dir_2 dir_3, If a directory name provided as an argument (i.e., input) to, mkdir is the same as that of an existing directory or file in, the same directory in which the user is asking mkdir to, create the new directory, mkdir will return a warning, message such as mkdir: cannot create directory `dir_1':, File exists and will not create a file with that name., However, it will then continue to create directories for any, other names provided as arguments., It is necessary for a user to have write permission (i.e.,, permission from the system to create or change a file or, directory) in the parent directory (i.e., the directory in which, the new directory is to be created) in order to be able to, create a new directory., Directories created by mkdir automatically include two, hidden directories, one representing the directory just, created (and represented by a single dot) and the other, representing its parent directory (and represented by two, consecutive dots). This can be seen by using the ls (i.e.,, list) command with its -a option, which tells ls to show all, directories and files, (including hidden ones) in any directory, provided to it as an argument, or in the current directory if, there are no arguments, i.e.,, ls -a, , a program) permissions enabled for the owner (i.e., the, creator of the directory by default) and group and the read, and execute permissions enabled for other users. Thus,, for example, to create a directory named dir_4 for which, all three types of permissions were enabled for all users,, the sequence 777 would be employed after -m, for example:, , The -p (i.e., parents) option creates the specified, intermediate directories for a new directory if they do not, already exist. For example, it can be used to create the, following directory structure:, mkdir -p food/fruit/citrus/oranges, It is very easy to confirm that this series of directories has, been created by using the du (i.e., disk usage) command, with the name of the first directory as an argument. In the, case of the above example this would be, du food, Other options include -v (i.e., verbose), which returns a, message for each created directory, --help, which returns, brief information about mkdir, and --version, which returns, the version number of the currently installed mkdir program, touch command, The touch command updates the access and modification, times of each FILE to the current system time., If you specify a FILE that does not already exist, touch, creates an empty file with that name., If the FILE argument is a dash ("-") is handled specially, and causes touch to change the times of the file associated, with standard output., $ touch file1 file2 file3, $ ls -l, total 4, drwxr-xr-x 2 raghu raghu 4096 2012-07-06 14:09 example, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file2, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, A feature of touch is that, in contrast to some commands, such as cp (which is used to copy files and directories), and mv (which is used to move or rename files and, , mkdir's -m option is used to control the permissions of, new directories. New directories are by default created, with the read, write and execute (i.e., run as a program if, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 81
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directories), it does not automatically overwrite (i.e., erase, the contents of) existing files with the same name. Rather,, it merely changes the last access times for such files to, the current time., Several of touch's options are specifically designed to allow, the user to change the timestamps for files. For example,, the -a option changes only the access time, while the -m, option changes only the modification time. The use of both, of these options together changes both the access and, modification times to the current time, for example:, touch -am file3, The -r (i.e., reference) option followed directly by a space, and then by a file name tells touch to use that file's time, stamps instead of current time. For example, the following, would tell it to use the times of file4 for file5:, touch -r file4 file5, The -B option modifies the timestamps by going back the, specified number of seconds, and the -F option modifies, the time by going forward the specified number of seconds., For example, the following command would make file7 30, seconds older than file6., touch -r file6 -B 30 file7, The -d and -t options allow the user to add a specific last, access time. The former is followed by a string (i.e.,, sequence of characters) in the date, month, year,, minute:second format, and the latter uses a, [[CC]YY]MMDDhhmm[.ss] format. For example, to change, the last access time of file8 to 10:22 a.m. May 1, 2005, 1, May 2005 10:22 would be enclosed in single quotes and, used as follows, i.e.,:, touch -d '1 May 2005 10:22' file8, Partial date-time strings can be used. For example, only, the date need be provided, as shown for file9 below (in, which case the time is automatically set to 0:00):, touch -d '14 May' file9, Just providing the time, as shown below, automatically, changes the date to the current date:, touch -d '14:24' file9, The most commonly used way to view the last modification, date for files is to use the ls command with its -l option., For example, in the case of a file named file10 this would, be, ls -l file10, The complete timestamps for any file or directory can be, viewed by using the stat command. For example, the, following would show the timestamps for a file named file11:, stat file11, The --help option displays a basic list of options, and the, --version option returns the version of the currently installed, touch program., , 82, , Copy, move and remove commands, Copy command, The cp command is used to copy files and directories., The copies become independent of the originals (i.e., a, subsequent change in one will not affect the other)., cp's basic syntax is, $cp source destination, As a safety precaution, by default cp only copies files and, not directories. If a file with the same name as that assigned, to the copy of a file (or a directory with the same name as, that assigned to the copy of a directory) already exists, it, will be overwritten (i.e., its contents will be lost). However,, the owner, group and permissions for the copy become, the same as those of the file with the same name that it, replaced. The last access time of the source file and the, last modification time of the new file are set to the time, the copying was performed., When a copy is made of a file or directory, the copy must, have a different name than the original if it is to be placed, in the same directory as the original. However, the copy, can have the same name if it is made in a different directory., Thus, for example, a file in the current directory (i.e., the, directory in which the user is currently working) named, file1 could be copied with the same name into another, directory, such as into /home/john/, as follows:, cp file1 /home/john/file1, Any number of files can be simultaneously copied into, another directory by listing their names followed by the, name of the directory. cp is an intelligent command and, knows to do this when only the final argument (i.e., piece, of input data) is a directory. The files copied into the, directory will all have the same names as the originals., Thus, for example, the following would copy the files named, file2, file3 and file4 into a directory named dir1:, cp file2 file3 file4 dir1, The -r (i.e., recursive) option, which can also be written, with an upper case R, allows directories including all of, their contents to be copied. (Directories are not copied by, default in order to make it more difficult for users to, accidentally overwrite existing directories which have the, same name as that assigned to the copy being made and, which might contain critical directory structures or, important data.) Thus, for example, the following command, would make a copy of an existing directory called dir2,, inclusive of all it contents (i.e., files, subdirectories, their, subdirectories, etc.), called dir3:, cp -r dir2 dir3, The -i (i.e., interactive) option prompts the user in the event, that any name assigned to a copy is already in use by, another file and that file would thus be overwritten. Entering, the letter y (either lower case or upper case) in response, to the prompt causes the command to continue; any other, answer prevents the command from overwriting the file., Thus, for example, if it is desired to make a copy of a, directory called dir4 and call it dir5 and if a directory named, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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dir4 already exists, the following would prompt the user, prior to replacing any files with identical names in the latter, directory:, cp -ri dir4 dir5, The -a option preserves as much of the structure and, attributes of the original directory and its contents as, possible in the new directory and is thus useful for creating, archives. It is similar to the -r option in that it copies, directories recursively; however, it also never follows, symbolic links. It is equivalent to the -rdp combination of, options., All the files in a directory can be copied to another directory, by using the star wildcard. The star character represents, any single character or any combination of characters., Thus, for example, the following would copy all of the files, in a directory named dir6 into another existing directory, called dir7:, cp dir6/* dir7, cp can also be used with the star wildcard or other pattern, matching characters to selectively copy files and, directories. For example, to copy all of the files in the, current directory that have the filename extension .html, into another existing directory called dir8, the following, would be used:, cp *.html dir8, In this case, the star wildcard represents anything whose, name ends with the .html extension., Among the other options for cp are -b, which makes backup, copies of each destination file, -f (i.e., force), which removes, destination files that cannot be opened and tries again, s, which makes symbolic links instead of copying, -u (i.e.,, update), which copies only if the source file is newer than, the destination file or if the destination file is missing, -v, (i.e., verbose), which makes brief comments about what, is going on, and -x, which tells cp to stay on the same, filesystem., Move command, The mv command is used to rename and move files and, directories. Its general syntax is:, $ mv source destination, The arguments are names of files and directories. If two, file names are provided as arguments, mv renames the, first as the second. If a list of arguments is provided and, the final argument in the sequence is the name of an, existing directory, mv moves all of the other items into, that directory. If the final argument is not an existing, directory and more than two arguments are provided, an, error message is returned., If the destination file is located in the same directory as, the source file, then the source file can only be renamed., If both are in different directories, then the source file is, moved to the directory named in the destination argument,, in which it can keep its original name or be assigned a, new name. If the target is a directory, then the source file, , or directory is moved into that directory and retains its, original name., Thus, for example, the following would rename a file called, file1 to file2, while keeping it in the current directory (i.e.,, the directory in which the user is currently working):, mv file1 file2, The following would move a file named file3, without, changing its name, from the current directory to an existing, subdirectory of the current directory named dir1:, mv file3 dir1/file3, mv can be used to move any number of files and directories, simultaneously. For example, the following command, moves all files and directories, including all the contents, of those directories, from the current directory to the, directory /home/alice/new/:, mv * /home/alice/new/, The asterisk is a wildcard character that represents any, string (i.e., sequence of characters). Thus, in the above, example it represents the name of every file and directory, in the current directory., mv makes it as easy to move a file or directory up the, hierarchy of directories (i.e., closer to the root directory), as down it. For example, the following would move a file, named file4, which is currently located in the subsubdirectory dir/dir/ of the user's home directory, to the, top level in the user's home directory:, mv dir/dir/file4 ~, The root directory is the directory that contains all other, directories on a Unix-like operating system and which is, at the top of the hierarchy of directories. A user's home, directory is the directory in which a user finds itself by, default after logging into the system and which can be, represented by the tilde (wavy horizontal linecharacter)., By default, mv does not provide any confirmation on the, display screen if its action is completed without problems., This is consistent with the rule of silence tenet of the Unix, philosophy., Thus it is wise for users new to Unix-like operating, systems to always use the -i option, which makes mv, interactive in the situation in which files and/or directories, with the same name already exist in the destination, directory. For example, the above command would be made, interactive as follows:, mv -i * /home/alice/new/, Among mv's few other options are -b, which tells it to make, a backup copy of each file that would otherwise be, overwritten or removed, and -v, which tells it to beverbose, and display the name of each file before moving it. Detailed, information (including all options) about mv can be obtained, by using its --help option, and information about the current, version can be obtained by using its --version option., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 83
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Remove or Delete, , begins with a dash or hyphen. For example, the following, removes a directory named -dir1:, , $ rmdir, 'rmdir' command removes any empty directories, but, cannot delete a directory if a file is present in it. To use, 'rmdir' command, you must first remove all the files present, the directory you wish to remove (and possibly directories, if any)., Remove files and directories, The rm (i.e., remove) command is used to delete files and, directories on Linux and other Unix-like operating systems., The general syntax for rm is:, rm [options] [-r directories] filenames, The items in square brackets are optional. When used, just with the names of one or more files, rm deletes all, those files without requiring confirmation by the user. Thus,, in the following example, rm would immediately delete the, files named file1, file2 and file3, assuming that all three, are located in the current directory (i.e., the, directory in which the user is currently working):, rm file1 file2 file3, Error messages are returned if a file does not exist or if, the user does not have the appropriate permission to delete, it. Write-protected files prompt the user for a confirmation, (with a y for yes and an n for no) before removal. Files, located in write-protected directories can never be removed,, even if those files are not write-protected., The -f (i.e., force) option tells rm to remove all specified, files, whether write-protected or not, without prompting the, user. It does not display an error message or return error, status if a specified file does not exist. However, if an, attempt is made to remove files in a write-protected, directory, this option will not suppress an error message., The -i (i.e., interactive) option tells rm to prompt the user, for confirmation before removing each file and directory. If, both the -f and -i options are specified, the last one specified, takes affect., As a safety measure, rm does not delete directories by, default. In order to delete directories, it is necessary to, use the -r option, which is the same as the -R option. This, option recursively removes directories and their contents, in the argument list; that is, the specified directories will, first be emptied of any subdirectories (including their, subdirectories and files, etc.) and files and then removed., The user is normally prompted for removal of any writeprotected files in the directories unless the -f option is, used., If a file encountered by rm is a symbolic link, the link is, removed, but the file or directory to which that link refers, will not be affected. A user does not need write permission, to delete a symbolic link, as long as the user has write, permission for the directory in which that link resides., The rm command supports the -- (two consecutive dashes), parameter as a delimiter that indicates the end of the, options. This is useful when the name of a file or directory, 84, , rm -r -- -dir1, Other options include -v (i.e., verbose), which provides, additional information about what is happening, --help,, which provides basic documentation about rm, and -version, which tells the version of rm that is currently in, use. Some differences exist among the various versions, of rm, so it is always wise to read the documentation for, the particular system., The rmdir command differs from rm in that it is only used, to remove empty directories, The rmdir command, The rmdir command is used to remove empty directories, in Linux, The syntax for rmdir is, rmdir [option] directory_names, When used without any options, rm will delete any empty, directories whose names are supplied as arguments (i.e.,, inputs) regardless of whether such directories have write, permission or not. Thus, for example, the following, command would remove two empty directories named dir1, and dir2 that are located in the current directory (i.e., the, directory in which the user is currently working):, rmdir dir1 dir2, The ability to remove only empty directories is a built-in, safeguard that helps prevent the accidental loss of data., This is important because once deleted, it is extremely, difficult or impossible to recover deleted data on Unix-like, operating systems1., The -p (i.e., parents) option tells rmdir to remove the parent, directories of the specified directory if each successive, parent directory will, in turn, become empty and if each, parent directory has write permission. Thus, for example,, the following would remove dir5, dir4 and dir3 if dir5 were, empty, dir4 only contained dir5 and dir3 only contained, dir4 (which, in turn, contained dir5):, rmdir -p dir3/dir4/dir5, This provides a symmetry with the -p option of the mkdir, command, which is used to create directories. Thus, the, above set of nested directories could be easily created, with the following:, mkdir -p dir3/dir4/dir5, In contrast to the rm command, which is used to delete, both files and directories, there is no -r option for rmdir. at, least on the GNU version that is standard on Linux. That, option allows rm to recursively delete a directory by first, deleting all of its contents, beginning with those in the, lowest levels of subdirectories. Thus, if a user wants to, remove an entire directory structure, it is usually most, efficient to use rm with its -r option rather than trying to, first remove the contents of each directory, its, subdirectories, etc., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Three options that rmdir shares with rm are -v (i.e., verbose),, which provides additional information about what is, happening, --help, which provides basicdocumentation, about rmdir, and --version, which tells the version of rmdir, that is currently in use. Some differences exist among the, various versions of rmdir, so it is always wise to read the, documentation for the particular system., Listing and combining files with the cat command, The cat (concatenate file) command is used to send the, contents of files to your screen. This, command may also be used to send files' contents into, other files. Hour 6 covers terms such as standard input,, standard output, and redirection, and this section shows, you some basic uses for this command., Although cat may be useful for reading short files, it is, usually used to either combine, create, overwrite, or, append files. To use cat to look at a short file, you can, enter, $ cat test.txt, This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., The cat command also has a number of options. If you'd, like to see your file with line, numbers, perhaps to note a specific phrase, you can use, the -n option:, , $ cat test.txt test2.txt, The output will be exactly the same as if had used a, wildcard. But looking at several files is only one way to, use cat. You can also use the cat command with the, redirection operator > to combine files. For example, if, you would like to combine test.txt and test2.txt into a, third file called test3.txt, you can use, $ cat test* > test3.txt, check the result with, # ls -l test*, In this case, user first decide whether you want the contents, of test.txt to go into test2.txt, or the contents of test2.txt, to go into test.txt . Then, using cat with the >> redirection, operator, you might type, $ cat test.txt >> test2.txt, This appends the contents of test.txt to the end of the, test2.txt . To check the results, use cat again:, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., This text file was created by the cat command., Cat could be the world's simplest text editor., If you read this book, you'll learn how to use cat., This is the last line of text in this file., Note that if you had entered the command., , $ cat -n test.txt, , • This text file was created by the cat command., • Cat could be the world's simplest text editor., • If you read this book, you'll learn how to use cat., • This is the last line of text in this file., and also use cat to look at several files at once, because, cat accepts wildcards, for example:, , $ cat -n test.txt >> test2.txt, The test2.txt file would look like, $ cat test2.txt, This is the first line of test2.txt., This file was also created by cat., This is the last line of test2.txt., , $ cat -n test*, , • This text file was created by the cat command., , • This text file was created by the cat command., , • Cat could be the world's simplest text editor., , • Cat could be the world's simplest text editor., , • If you read this book, you'll learn how to use cat., , • If you read this book, you'll learn how to use cat., , • This is the last line of text in this file., , • This is the last line of text in this file., • This file was also created by cat., , Finally, here's a trick you can use if you want to create a, short text file without running a word processor or text, editor. Because the cat command can read the standard, input (more about this in Hour 6), you can make the cat, command create a file and fill it with your keystrokes., , • This is the last line of test2.txt., , Here's how:, , • This is the first line of test2.txt., , As you can see, cat has also included a second file in its, output, and has numbered each line of the output, not, each file. Note that also see both files with, , $ cat > myfile.txt, Now, enter some text:, $ cat > myfile.txt, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 85
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This is the cat word processor., This is the end of the file., Then, when you're done typing, press Ctrl+D to close the, file. To see if this works, try, $ ls -l myfile.txt, -rw-rw-r-- 1 bball bball 61 Nov 12 18:26 myfile.txt, $ cat myfile.txt, This is the cat word processor., This is the end of the file., user should also know that the cat command will print out, the contents of any file, and not, just text files. Although cat may be useful to look at one or, several short files,, Other file commands, The clear Command, The clear command is used to remove all previous, commands and output from consoles and terminal, windows in Unix-like operating systems., A console is an all-text mode user interface that, occupies the entire screen of the display device and which, does not sit on top of a graphical user interface (GUI). A, terminal window is a text-only window in a GUI that, emulates a console and which can be opened by clicking, the appropriate icon (i.e., small image) or menu item., , As another example, the following displays the man page, about the man pages:, man man, man automatically sends its output through a pager,, usually the program less. A pager is a program that causes, the output of any program to be displayed one screenful, at a time, rather than having a large amount of text scroll, down the screen at high (and generally unreadable) speed., less writes a colon at the bottom of the screen to indicate, the end of the on-screen page. The user can move to the, next page by pushing the space bar and can return to the, previous page by pressing the b key. Pressing the q exits, the man pages and returns the user to the shell program., Each man page is a self-contained article that is divided, into a number of sections, the headers for which are labeled, with upper case letters. The sections for commands are, typically something like NAME, SYNOPSIS,, DESCRIPTION, OPTIONS, AUTHOR, BUGS,, COPYRIGHT, HISTORY and SEE ALSO, although there, may be some differences according to the particular, command. Some of these might be broken down into, subsections, particularly OPTIONS in the case of a, command that has numerous options., Also, the man pages as a whole are organized into, sections, each containing pages about a specific category, of topics as shown below. The section to which an article, belongs is indicted in parenthesis in the top line, before, the NAME header., , Clear is one of the very few commands in Unix-like, operating systems that accepts neither options nor, arguments (i.e., input files). That is, it is only used as, follows:, , 1. executable programs or shell commands, , Clear, , 4. special files (i.e., devices in the /dev directory), , After the clear command has been issued, all that, remains on the display screen is the command prompt in, the upper left hand corner. A command prompt, also, referred to as a prompt, is a short text message at the, start of a line that informs the user that the system is, ready for the next command, data element or other, input., , 5. file formats, , The descriptions are rather terse, and they can seem, somewhat cryptic to new users. However, users typically, find them to be increasingly useful as they become more, familiar with them and gain experience in the use of Unixlike operating systems., , Some topic names will have multiple articles, depending, on context. For instance, there are two articles for mount,, one corresponding to its use as a command in system, management (i.e., to logically attach partition or other, devices to the main filesystem) and the other for use in, the C programming language. Generally, the most, commonly used topic is displayed by default, and there, are references to any other topics with the same name in, the SEE ALSO section at the bottom of the final on-screen, page., , The man command itself is extremely easy to use. Its, basic syntax is, man [option(s)] keyword(s), man is most commonly used without any options and, with only one keyword. The keyword is the exact name of, the command or other item for which information is desired., For example, the following provides information about the, ls command (which is used to list the contents of any, specified directory):, man ls, 86, , 2. system calls, 3. library routines, , 6. games, 7. macro packages, 8. system administration commands, 9. kernel routines, , The syntax to specify an article from a particular section, is:, man section_number keyword, , Thus, for example, the following would display the article, about mount from Section 2 instead of from the default, Section 8:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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man 2 mount, The -w and -W options tell man to not actually display the, man pages, but to provide the location(s) of the file(s) that, would be formatted or displayed. If noarguments (i.e., input, files) are provided, a list of directories that is searched by, man for man pages is returned., The -f option produces the same output as the whatis, command. whatis provides very brief descriptions of, commands from a database that is automatically created, from the first line of the NAME section of each relevant, man page., The Whoami and who command, The whoami command writes the user name (i.e., login, name) of the owner of the current login session to standard, output. Standard output is, by default, the display screen,, unless redirected to a file, printer, etc., , as additional information about each of those users, (including login times and terminal numbers). It also, differs in that, in the event of a change in ownership of a, login session through the use of the su command, it, reports the original owner of the session, whereas whoami, provides the user name of the effective (i.e., current) owner, of the session., stat command, File Stat - Display Information About File, For example, to find out more information about, 101hacks.txt file, execute the stat command as shown, below., $ stat 101hacks.txt, File: `/home/sathiyamoorthy/101hacks.txt', Size: 854, , Blocks: 8 IO Block: 4096 regular file, , whoami is particularly useful when using shells such as, ash and sh that do not show the name of the current user, in the command prompt (a short text message at the start, of the command line on an all-text display). It is also useful, for confirming the current owner of a session after using, the su (i.e., substitute user) command, which changes, the owner of the session without the original owner having, to first log out., , Device: 801h/2049d, , A shell is a program that provides the traditional, text-only, user interface forUnix-like operating systems. Its primary, function is to read commands that are typed into a console, (i.e., an all-text display mode) or terminal window(an alltext window in a GUI) and then execute (i.e., run) them., , Details of Linux stat command output, , The formal syntax for whoami is:, , • Blocks: 8 - Total number of blocks used by this file., , whoami [option], When used without any options or redirection, as it usually, is, i.e.,, Whoami, , Inode: 1058122, , Links: 1, , Access: (0600/-rw-------) Uid: ( 1000/ sathiya), Gid: ( 1000/ sathiya), Access: 2009-06-28 19:29:57.000000000 +0530, Modify: 2009-06-28 19:29:57.000000000 +0530, Change: 2009-06-28 19:29:57.000000000 +0530, , • File: `/home/sathiyamoorthy/101hacks.txt' - Absolute, path name of the file., , • Size: 854 - File size in bytes., • IO Block: 4096 - IO block size for this file., • Regular file - Indicates the file type. This indicates, , that this is a regular file. Following are available file, types., , and followed by pressing the ENTER key, whoami displays, on the monitor screen the user name of the owner of the, current session., , − regular file. ( ex: all normal files )., , There are only two options for whoami: --help and --version., The former outputs the very brief description that is, contained in the man (i.e., built-in system manual) pages,, and the latter outputs the number of the version currently, installed on the system., , − socket. ( ex: sockets )., , whoami produces the same result as the id command, (which by default provides more detailed information about, the current user than does whoami) when id is used with, its -u and -n options, i.e.,, , − character special file. ( ex: terminal device file)., , id -un, The -u option tells id to provide only the identification for, the current owner of the session, and the -n option tells it, to present that identification as the user name instead of, as a number., The who command differs from whoami in that it provides, a list of all users currently logged into the system as well, , − directory. ( ex: directories )., − symbolic link. ( ex: symbolic links. ), − block special file ( ex: hard disk )., • Device: 801h/2049d - Device number in hex and device, number in decimal, , • Inode: 1058122 - Inode number is a unique number for, , each file which is used for the internal maintenance by, the file system., , • Links: 1 - Number of links to the file, • Access: (0600/-rw---): Access specifier displayed in, , both octal and character format. Let us see explanation, about both the format., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 87
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• Uid: ( 1000/ sathiya) - File owner's user id and user, , between. Thus, the following command would produce the, same result:, , • Gid: ( 1000/ sathiya) - File owner's group id and group, , head -n 15 aardvark armadillo, , name are displayed., name are displayed., , • Access: 2009-06-28 19:29:57.000000000 +0530 - Last, access time of the file., , • Modify: 2009-06-28 19:29:57.000000000 +0530 - Last, modification time of the file., , • Change: 2009-06-28 19:29:57.000000000 +0530 - Last, change time of the inode data of that file., , Dir Stat - Display Information About Directory You can, use the same command to display the information about, a directory as shown below., $ stat /home/ramesh, , In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell head how many lines to, return. Thus, the following would produce the same, result as the above commands:, head -15 aardvark armadillo, head can also return any desired number of bytes (i.e., a, sequence of eight bitsand usually long enough to represent, a single character) from the start of each file rather than a, desired number of lines. This is accomplished using the coption followed by the number of bytes desired. For, example, the following would display the first five bytes of, each of the two files provided:, , File: `/home/ramesh', , head -c 5 aardvark anteater, , Size: 4096 Blocks: 8 IO Block: 4096 directory, , When head counts by bytes, it also includes the newline, character, which is anon-printing (i.e, invisible) character, that is designated by a backslash and the letter n (i.e.,, \n). Thus, for example, if there are three new, blank lines, at the start of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or on, paper)., , Device: 803h/2051d Inode: 5521409 Links: 7, Access: (0755/drwxr-xr-x) Uid: ( 401/ramesh), Gid: (401/ramesh), Access: 2009-01-01 12:17:42.000000000 -0800, Modify: 2009-01-01 12:07:33.000000000 -0800, Change: 2009-01-09 12:07:33.000000000 -0800, The head command reads the first few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the display screen)., , The number of bytes or lines can be followed by a, multiplier suffix. That is, adding the letter b directly after, the number of bytes multiplies it by 512, kmultiplies it by, 1024 and m multiplies it by 1048576. Thus, the following, command would display the first five kilobytes of the file, aardvark:, , head's basic syntax is:, , head -c5k aardvark, , head command, , head [options] [file(s)], The square brackets indicate that the enclosed items are, optional. By default, head returns the first ten lines of each, file name that is provided to it., For example, the following will display the first ten lines of, the file namedaardvark in the current directory (i.e., the, directory in which the user is currently working):, head aardvark, If more than one input file is provided, head will return the, first ten lines from each file, precede each set of lines by, the name of the file and separate each set of lines by one, vertical space. The following is an example of using head, with two input files:, head aardvark armadillo, If it is desired to obtain some number of lines other than, the default ten, the -noption can be used followed by an, integer indicating the number of lines desired. For example,, the above example could be modified to display the first, 15 lines from each file:, head -n15 aardvark armadillo, , The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter ccannot be omitted as, can the letter n, because in such case head would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like head: aardvark: invalid number of bytes:, head -c aardvark, If head is used without any options or arguments (i.e., file, names), it will await input from the keyboard and will, successively repeat (i.e., each line will appear twice) on, the monitor screen each of the first ten lines typed on the, keyboard. If it were desired to repeat some number of, lines other than the default ten, then the -n option would, be used followed by the integer representing that, number of lines (although, again, it is not necessary to, include the letter n), e.g.,, head -n3, As is the case with other command line (i.e., all-text mode), programs in Linuxand other Unix-like operating systems,, the output from head can redirectedfrom the display monitor, to a file or printer using the output redirection operator, (which is represented by a rightward-pointing angular, , -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, 88, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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bracket). For example, the following would copy the first, 12 lines of the file Yuriko to the fileDecember:, head -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two consecutive rightward pointing angle brackets) could, be used to add the output from head to the end of a file, with that name if it already existed (or otherwise create a, new file with that name), i.e.,, head -n 12 Yuriko >> December, The output from other commands can be sent via a pipe, (represented by thevertical bar character) to head to use, as its input. For example, the following sends the output, from the ls command (which by default lists the names of, the files and directories in the current directory) to head,, which, in turn, displays the first ten lines of the output that, it receives from ls:, ls | head, This output could easily be redirected, for example to the, end of a file namedfile1 as follows:, ls | head >> file1, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reverse alphabetic order, prior to appending file1:, ls | head | sort -r >> file1, The -q (i.e., quiet) option causes head to not show the file, name before each set of lines in its output and to eliminate, the vertical space between each set of lines when there, are multiple input sources. Its opposite, the -v (i.e., verbose), option, causes head to provide the file name even if there, is just a single input file., The tail command is similar to the head command except, that it reads the final lines in files rather than the first, lines., As is the case with other commands on Unix-like operating, systems, additional information can be obtained about head, and tail by using the man and infocommands to reference, the built-in documentation, for example, man head, or, info tail, tail command, The tail command reads the final few lines of any text, given to it as an input and writes them to standard output, (which, by default, is the monitor screen)., The basic syntax for tail is:, tail [options] [filenames], $ tail -n 4 /etc/passwd, , The square brackets indicate that the enclosed items are, optional. By default, tail returns the final ten lines of each, file name that is provided to it., For example, the following command will print (traditional, Unix terminology for write) the last ten lines of the file, named aardvark in the current directory (i.e., the director, in which the user is currently working) to the display, screen:, tail aardvark, If more than one input file is provided, tail will print the last, ten lines from each file to the monitor screen. Each set of, lines will be preceded by the name of the file and separated, by one vertical space from other sets of lines. The following, is an example of using tail with multiple input files:, tail file1 file2 file3, If it is desired to print some number of lines other than the, default ten, the -n option can be used followed by an integer, indicating the number of lines desired. For example, to, print the final 15 lines from each file in the above example,, the command would be modified as follows:, tail -n15 file1 file2 file3, -n is a very tolerant option. For example, it is not necessary, for the integer to directly follow it without a space in, between. Thus, the following command would produce the, same result:, tail -n 15 file1 file2 file3, In fact, the letter n does not even need to be used at all., Just the hyphen and the integer (with no intervening space), are sufficient to tell tail how many lines to print. Thus, the, following would produce the same result as the above, commands:, tail -15 file1 file2 file3, tail can also print any desired number of bytes (i.e., a, sequence of eight bits and usually long enough to represent, a single character) from the end of each file rather than a, desired number of lines. This is accomplished using the c option followed by the number of bytes desired. For, example, to view the final five bytes of each of the two files, aardvark and anteater, the following command would be, used:, tail -c 5 file1 file2, When tail counts by bytes, it also includes the newline, character, which is a non-printing (i.e, invisible) character, that is designated by a backward slash and the letter n, (i.e., \n). Thus, for example, if there are three new, blank, lines at the end of a file, they will be counted as three, characters, along with the printing characters (i.e.,, characters that are visible on the monitor screen or paper)., The number of bytes or lines can be followed by a multiplier, suffix. That is, adding the letter b directly after the number, of bytes multiplies it by 512, k multiplies it by 1024 and m, multiplies it by 1048576. Thus, the following command, would print the last five kilobytes of the file aardvark:, tail -c5k file1, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 89
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The -c option is less tolerant than the -n option. That is,, there is no default number of bytes, and thus some integer, must be supplied. Also, the letter c cannot be omitted as, can the letter n, because in such case tail would interpret, the hyphen and integer combination as the -n option. Thus,, for example, the following would produce an error message, something like tail: aardvark: invalid number of bytes:, tail -c file1, If tail is used without any options or arguments (i.e., inputs),, it will await input from the keyboard and will successively, repeat (i.e., each line will appear twice) on the monitor, screen each of the final ten lines typed on the keyboard. If, it were desired to repeat some number of lines other than, the default ten, then the -n option would be used followed, by the integer representing that number of lines (although,, again, it is not necessary to include the letter n), e.g.,, tail -n3, As is the case with other command line (i.e., all-text mode), programs in Unix-like operating systems, the output of, tail can be redirected from the monitor to a file or printer, using the redirection operator (which is represented by a, rightward pointing angular bracket). For example, the, following would write the final 12 lines of the file Yuriko to, the file December:, tail -n 12 Yuriko > December, If the file named December did not yet exist, the redirection, operator would create it; if it already existed, the redirection, operator would overwrite it. To avoid erasing data on an, existing file, the append operator (which is represented by, two rightward pointing angular brackets) could be used to, add the output from tail to the end of a file with that name, if it already existed (or otherwise create a new file with, that name), i.e.,, tail -n 12 Yuriko >> December, The output from other commands can be piped (i.e., sent), to tail to use as its input. For example, the following sends, the output from the ls command (which by default lists the, names of the files and directories in the current directory), to tail, which, in turn, prints the final ten lines of the output, that it receives from ls to the monitor screen:, ls | tail, , Tail can be instructed to begin printing from some number, of lines or bytes from the start of a file by preceding the, number with a plus sign instead of a minus sign. For, example, the following would print each of the designated, files to the display monitor beginning with the seventh line, and until the end:, tail +7 file1 file2 file3, The c option could be used to tell tail to print each of the, designated files beginning with the seventh byte instead, of the seventh line:, tail +7c file1 file2 file3, A particularly common application for tail is examining the, most recent entries in log files. This is because the newest, entries are appended to the ends of such files, which tail, excels in showing. As log files can be a rather long, this, can eliminate a lot of scrolling that would be necessary if, some other command were used to read them. For, example, the most recent entries to the log /var/log/, messages can easily be viewed by using the, following:, tail /var/log/messages, wc command, The wc (i.e., word count) command by default counts the, number of lines, words and characters in text., wc defines a word as a set of contiguous letters, numbers, and/or symbols which are separated from other characters, by one or more spaces, tabs and/or newline characters, (which are generated when the RETURN key is pressed)., When counting the number of characters, all characters, are counted, not only letters, numbers and symbols, but, also spaces, tabs and newline characters. A line is only, counted if it ends with a newline character., wc's syntax is, , This output could easily be redirected, for example to a, file named last_filenames as follows:, ls | tail >> last_filenames, It could also be piped to one or more filters for additional, processing. For example, the sort filter could be used with, its -r option to sort the output in reversealphabetic order, prior to writing to a file:, ls | tail | sort -r >> last_filenames, The -q (i.e., quiet) option causes tail to not print the file, name before each set of lines and to eliminate the vertical, space between each set of lines when there are multiple, input sources. The -v (i.e., verbose) option causes tail to, print the file name even if there is just a single input file., 90, , Tail could be viewed as a counterpart of the head command,, which always starts reading from the beginning of files, and which can continue until any specified distance from, the beginning. However, there are a few differences. Perhaps, the most useful of these is that tail is somewhat more, flexible in that, in addition to being able to start reading, any specified distance from the end of a file, it can also, start at any specified distance from the beginning of a file., , wc [options] [file_name(s)], The items in square brackets are optional. If no file names, are provided, wc reads from its standard input, which by, default is text entered at the keyboard., This can be seen by typing., wc, at the command line (i.e., in the all-text mode), pressing, the ENTER key to move to a new line and then typing, some text on one or more lines. The command isexecuted, (i.e., run) by pressing the ENTER key again and then, pressing the CONTROL and d keys simultaneously. This, causes wc to write in a new line (under the lines of text), its count of the numbers of lines, words and characters in, the text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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The following command counts the number of lines, words, and characters in a file named file1 that resides in the, current directory (i.e., the directory in which the user is, currently working) and likewise writes them, followed by, the name of the file, to standard output, which is by default, the display monitor:, , cat file6, grep command, grep is used to search text for patterns specified by the, user. It is one of the most useful and powerful commands, on Linux and other Unix-like operating systems., grep's basic syntax is:, , wc file1, wc can provide its output for multiple files by listing the, name of each separated by a space. For example,, wc file1 file2 file3, The numbers of lines, words and characters for each file, along with its name will be displayed on a separate line, and in the order that the files are listed as arguments(i.e.,, input files). In the case of multiple arguments such as, this, wc also provides an additional line that shows the, total number of lines, words and characters for all the files., Likewise, wc can provide a count for all of the text files, within a directory. This is accomplished by using the star, wildcard character, which represents everythingand is, designated by an asterisk ( * ). For example, the following, will display the number of lines, words and, characters for each file in the current directory (which is, represented by a dot) as well as totals for all files in the, directory:, wc . *, wc has only a few options, the most commonly used of, which restrict the information it provides. The -l option tells, wc to count only the number of lines, the -woption tells it, to count only the number of words, the -m option tells it to, count only the number of characters and the -c option, tells wc to count only the number ofbytes. Thus, for, example, the following displays just the number of words, in a file named file4:, wc -w file4, The following displays the number of characters in the, same file:, wc -m file4, As is generally the case with commands in Unix-like, operating systems, any combination of options can be, used together. For example, the following would count both, the numbers of lines and words in a file named file5:, wc -lw file5, Redirection can be used with wc to create more complex, commands. For example, the output from the above, command can be redirected using the standard output, redirection operator (which is designated by a rightward, pointing angle bracket) from the display screen to a file, named file6 with the following:, wc -lw file5 > file6, If file6 already exists, its contents will be overwritten; if it, does not exist, it will be created. The contents of file6 can, be easily confirmed with a text editor or with a command, such as cat, which is commonly used to read text files,, i.e.,, , grep [option(s)] pattern [file(s)], The items in square brackets are optional. When used, with no options and no arguments (i.e., input files), grep, searches standard input (which by default is text typed in, at the keyboard) for the specified pattern and returns each, line that contains a match to standard output (which by, default is the display screen)., A line of text is defined in this context not as what, appears as a line of text on the display screen but rather, as all text between two newline characters. Newline, characters are invisible characters that are represented in, Unix-like operating systems by a backslash followed by, the letter n and which are created when a user presses, the ENTER key when using a text editor (such as gedit)., Thus, a line of text returned by grep can be as short as a, single character or occupy many lines on the display, screen., grep can search any number of files simultaneously. Thus,, for example, the following would search the three files file1,, file2 and file3 for any line that contains thestring (i.e.,, sequence of characters) Lin:, grep Lin file1 file2 file3, Each result is displayed beginning on a separate line, and, it is preceded by the name of the file in which it was found, in the case of multiple files. The inclusion of the file names, in the output data can be suppressed by using the -h, option., grep is not limited to searching for just single strings. It, can also search for sequences of strings, including, phrases. This is accomplished by enclosing the sequence, of strings that forms the pattern in quotation marks (either, single or double). Thus, the above example could be, modified to search for the phrase Linux is:, grep 'Linux is' file1 file2 file3, Text searches with grep can be considerably broadened, by combining them with wildcards and/or performing, recursive searches. A wildcard is a character that can, represent some specific class of characters or sequence, of characters. The following is a modification of the above, example that uses the star wildcard (i.e., an asterisk),, which represents any character or sequence of characters,, to search all text files in the current directory (i.e., the, directory in which the user is currently working):, grep 'Linux is' *, , grep's search area can be broadened even further by using, its -r option to search recursively through an entire directory, tree (i.e., a directory and all levels of subdirectories within, it) rather than just the files within a specified directory. For, example, the following would search all files in the current, 91, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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directory and in all of its subdirectories (including their, subdirectories, etc.) for every line containing the full name, of the creator of Linux:, grep -r 'Linus Torvalds' *, One of the most commonly employed of grep's many, options is -i, which instructs it to ignore case, that is, to, ignore whether letters in the pattern and text searched are, lower case (i.e., small letters) or upper case (i.e., capital, letters). Thus, for instance, the previous example could, very easily be converted to a case-insensitive search as, follows:, grep -ir 'Linus Torvalds' *, This would produce the same results as, grep -ir 'linUS torvAlds' *, Another frequently used option is -c, which causes grep, to only report the number of times that the pattern has, been matched for each file and to not display the actual, lines. Thus, for instance, the following would show the, total number of times that the string inu appears in a file, named file4:, grep -c inu file4, Another useful option is -n, which causes grep to precede, each line of output with the number of the line in the text, file from which it was obtained. The -v option inverts the, match; that is, it matches only those lines that do not, contain the given pattern., The -w option tells grep to select only those lines that, contain an entire word or phrase that matches the, specified pattern. The -x option tells grep to select only, those lines that match exactly the specified pattern., The -l option tells grep to not return the lines containing, matches but to only return only the names of the files that, contain matches. The -L option is the opposite of the -l, option (and analogous to the -v option) in that it will cause, grep to return only the names of files that do not contain, the specified pattern., grep does not search the names of files for a specified, pattern, only the text contained within files. However,, sometimes it is useful to search the names of files, as, well as of directories and links, rather than the contents of, files. Fortunately, this can easily be accomplished by first, using the ls command to list the contents of a directory, and then using a pipe (which is represented by the vertical, bar character) to transfer its output to grep for searching., For example, the following would provide a list of all files,, directories and links in the current directory that contain, the string linu in their names:, ls | grep linu, The following example uses ls with its -l (i.e., long) option, (which is unrelated to grep's -l option) to find all filesystem, objects in the current directory whose permissions have, been set so that any user can read, write and execute, them:, ls -l | grep rwxrwxrwx, 92, , grep is very useful for obtain information from log and, configuration files. For example, it can be used to obtain, information about the USB (universal serial bus) devices, on a system by filtering the output from the dmesg, command (which provides the messages from the kernel, as a system is booting up) as follows:, dmesg | grep -i usb, Among grep's other options are --help, which provides a, very compact summary of some of its many capabilities,, and -V, or --version, which provides information about the, currently installed version., grep's search functionality can be even further refined, through the use of regular expressions. These are a pattern, matching system that uses strings constructed according, to pre-defined syntax rules to find desired patterns in text., Additional information about grep, including its use with, regular expressions, can be obtained from its built-in, manual page by using the man command, i.e.,, man grep, The name grep comes from a command in ed, which was, the original text editor on the UNIX operating system. The, command takes the form g/re/p, which means to search, globally for matches to the regular expression (i.e., re),, and print (which is UNIX terminology for write on the display, screen) lines that are found., ln command, ln command is used to create links. Links are a kind of, shortcuts to other files. The general form of command is:, $ ln TARGET LINK_NAME, There are two types of links, soft links and hard links. By, default, hard links are created. If you want to create soft, link, use -s option. In this example, both types of links are, created for the file usrlisting., $ ln usrlisting hard_link, $ ln -s usrlisting soft_link, $ ls -l, total 12, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file1, -rw-r--r-- 1 raghu raghu 0 2012-07-06 14:20 file3, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 hard_link, lrwxrwxrwx 1 raghu raghu 10 2012-07-09 14:00 soft_link > usrlisting, -rw-r--r-- 1 raghu raghu 491 2012-07-06 16:02 usrcopy, -rw-r--r-- 2 raghu raghu 491 2012-07-06 14:23 usrlisting, Some additional useful commands, alias command, 'alias' is another name for a command. If no argument is, given, it shows current aliases. Aliases can be used for, short names of commands. For example, you might use, clear command frequently. You can create an alias for it:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ alias c="clear", Next time enter c on command line, your screen will be, clear. Current aliases can be checked with 'alias', command:, $ alias, alias alert='notify-send --urgency=low -i "$([ $? = 0 ] &&, echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/, ^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"', alias c='clear', alias egrep='egrep --color=auto', alias fgrep='fgrep --color=auto', alias grep='grep --color=auto', alias l='ls -CF', alias la='ls -A', alias ll='ls -alF', alias ls='ls --color=auto', w command, The w command shows who is logged in to the system, and what they are doing., A login, logging in or logging on is the entering of identifier, information into a system by a user in order to access, that system (e.g., a computer or a website). It generally, requires the user to enter two pieces of information, first a, user name and then a password., The basic syntax of w is:, w [options] [username1, username2, . . .], The square brackets indicated that the enclosed items, are optional. When used without any options, w sends to, standard output (which is by default the display screen) a, header line followed by a table that contains a line of data, for each user currently logged in., The header shows six items: the current time, how long, the system has been running (in minutes) since it was, booted up (i.e., started up), how many users are currently, logged on, and the system load averages, i.e., the average, number of processes active, during the last one, five and, 15 minutes. A process is an executing(i.e., running), instance of a program., The main part of w's output consists of a table showing, eight items of information for each user currently logged, into the system. The eight columns are labeled USER,, TTY, FROM, LOGIN@, IDLE, JCPU, PCPU and WHAT., USER is the login name of the user. TTY (which now, stands for terminal type but originally stood for teletype), is the name of the console or terminal (i.e., combination, of monitor and keyboard) that the user logged into, which, can also be found by using the tty command. Every time, a user logs in across the network, a new tty is assigned, to that user., , independent logical consoles that run in separate login, sessions, but which are accessed from the same physical, console (i.e., the same keyboard and screen). That is,, each virtual console can have a different, or the same,, user logged into it. On a Red Hat system, seven virtual, consoles are configured and active by default., FROM is the remote host (i.e., the name of some other, computer), if any, that the user logged into. LOGIN@ is, the time at which the user logged in. IDLE is the number, of hours and minutes since the user last typed anything, at the keyboard., JCPU is the number of minutes accumulated by all, processes attached to the tty. It does not include past, background processes (i.e., low priority processes that, operate only in gaps between higher priority foreground, processes), but it does include currently running, background processes., PCPU is the time consumed by the current process,, named in the WHAT column. WHAT lists the name of the, current process along with any options and arguments(i.e.,, input files) used with the command that launched it., Among the more useful of w's few options is -h, which, tells it to omit the header header line from its output. The, -s option tells it to use the short format, which omits the, login time, JCPU and PCPU columns. The -l option creates, a long listing, which is the same as the default. The -V, option displays the version number of the currently installed, w program., By default, w reports on all users. However, it can be made, to report on only a specified set of users by providing those, usernames in a comma-separated list., w provides information similar to that which would be, provided by a combination of the uptime, who and ps -a, commands. uptime produces a single line of output that, is the same as w's header line. who shows who is currently, logged into the system. ps -a lists all processes with a tty, except session leaders (i.e., processes that created, sessions)., w can be useful, but there are some faults with the, information it provides, and thus its output should only be, considered approximate. In particular, the notion of, thecurrent process is unclear and there are some problems, detecting background processes, even though they usually, account for much of the load on the system. Also, the, CPU time is only an estimate; for example, if a user leaves, a background process running after logging out, the time, is credited to the person currently on that terminal., last command, Display information about the users who logged in and out, of the system. The output of last can be very large, so the, following output has been filtered (through head) to display, top 10 lines only:, , The consoles can be real or virtual. A feature of Linux, systems is the use of virtual consoles, which act as, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 93
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$ last | head, root tty1 Mon Jul 9 10:06 still logged in, root tty1 Mon Jul 9 10:06 - 10:06 (00:00), raghu pts/1 :0.0 Mon Jul 9 10:05 - 10:06 (00:00), raghu pts/0 :0.0 Mon Jul 9 09:34 still logged in, raghu tty7 :0 Mon Jul 9 09:19 still logged in, , /dev/sda2 209715196 196519248 13195948 94%/, media/Data, fdisk command, The fdisk is the tool for getting partition information, adding, and removing partitions.The fdisk tool requires super user, privileges. To list all the partitions of all the hard drives, available:, $ fdisk -l, , reboot system boot 2.6.38-13-generi Mon Jul 9 09:09 10:12 (01:02), , Disk /dev/sda: 320.1 GB, 320072933376 bytes, , raghu tty7 :0 Sun Jul 8 23:36 - 00:30 (00:54), , 255 heads, 63 sectors/track, 38913 cylinders, , reboot system boot 2.6.38-13-generi Sun Jul 8 23:36 00:30 (00:54), , Units = cylinders of 16065 * 512 = 8225280 bytes, , raghu tty7 :0 Sun Jul 8 21:07 - down (01:06), reboot system boot 2.6.38-13-generi Sun Jul 8 21:07 22:14 (01:07), A similar command is lastb that shows last bad login, attempts. But this command must be run as root otherwise, would get an error of permission denied, $ lastb, raghu tty2 Mon Jul 9 10:16 - 10:16 (00:00), UNKNOWN tty2 Mon Jul 9 10:15 - 10:15 (00:00), ubuntu tty8 :1 Mon Jul 2 10:23 - 10:23 (00:00), btmp begins Mon Jul 2 10:23:54 2012, du command, du command determines disk usage of a file. If the, argument given to it is a directory, then it will list disk, usage of all the files and directories recursively under that, directory:, $ du /etc/passwd, 4 /etc/passwd, , Sector size (logical/physical): 512 bytes / 512 bytes, I/O size (minimum/optimal): 512 bytes / 512 bytes, Disk identifier: 0x396f396f, Device Boot Start End Blocks Id System, /dev/sda1 1 2611 20971520 7 HPFS/NTFS, /dev/sda2 2611 28720 209715200 7 HPFS/NTFS, /dev/sda3 * 28720 38914 81882113 5 Extended, /dev/sda5 28720 33942 41943040 7 HPFS/NTFS, /dev/sda6 33942 34464 4194304 7 HPFS/NTFS, /dev/sda7 34464 35739 10240000 83 Linux, /dev/sda8 35739 36376 5120000 83 Linux, /dev/sda9 36376 36886 4096000 82 Linux swap / Solaris, /dev/sda10 36887 38276 11164672 83 Linux, /dev/sda11 38277 38914 5117952 83 Linux, fdisk is an interactive tool to edit the partition table. It, takes a device (hard disk) as an argument, whose partition, table needs to be edited., $ fdisk /dev/sda, , $ du hello/, 4 hello/orb.db/logs, , WARNING: DOS-compatible mode is deprecated. It's, strongly recommended to switch off the mode (command, 'c') and change display units to sectors (command 'u')., , 20 hello/orb.db, , Command (m for help): m, , 52 hello/HelloApp, , 108 hello/, , Command, , action, , df command, , a, , toggle a bootable flag, , df reports file system usage. For example:, , b, , edit bsd disk label, , c, , toggle the dos compatibility flag, , Filesystem 1K-blocks Used Available Use% Mounted on, , d, , delete a partition, , /dev/sda7 10079084 7372872 2194212 78% /, , l, , list known partition types, , none 1522384 768 1521616 1% /dev, , m, , print this menu, , $ df, , none 1529012 252 1528760 1% /dev/shm, , n, , add a new partition, , none 1529012 108 1528904 1% /var/run, , o, , create a new empty DOS partition table, , none 1529012 4 1529008 1% /var/lock, , p, , print the partition table, , /dev/sda8 5039616 3758824 1024792 79% /home, , q, , quit without saving changes, , 94, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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s, , create a new empty Sun disklabel, , t, , change a partition's system id, , u, , change display/entry units, , v, , verify the partition table, , w, , write table to disk and exit, , x, , extra functionality (experts only), , Pressing 'm' at the fdisk prompt prints out above help that, lists all the commands available for fdisk. A new, partition can be created with n and an existing partition, can be deleted with d command. When you are done editing, the partitions, press w to write the changes to the disk,, and finally, q to quit from fdisk (q dies not save changes)., netstat command, 'netstat' is the command used to check the network, statistics of the system. It will list the current network, connections, routing table information, interface, statistics, masquerade connections and a lot more, information., $ netstat | head, Active Internet connections (w/o servers), Proto Recv-Q Send-Q Local Address Foreign Address State, Active UNIX domain sockets (w/o servers), Proto RefCnt Flags Type State I-Node Path, unix 13 [ ] DGRAM 8498 /dev/log, unix 2 [ ] DGRAM 6824 @/org/kernel/udev/udevd, unix 3 [ ] STREAM CONNECTED 56738 /var/run/dbus/, system_bus_socket, unix 3 [ ] STREAM CONNECTED 56113, , All of the files on a system have permissions that allow or, prevent others from viewing, modifying or executing. If the, file is of type Directory then it restricts different actions, than files and device nodes. The super user "root" has the, ability to access any file on the system. Each file has, access restrictions with permissions, user restrictions with, owner/group association. Permissions are referred to as, bits., If the owner read & execute bit are on, then the permissions, are:, There are three types of access restrictions:, Permission, , (view), , r or 4, , write, , (edit), , w or 2, , execute, , passwd command, Change your password with 'passwd' command., shutdown -h now, Finally shut down your system using this command., Understanding and using file permissions, In Linux and Unix, everything is a file. Directories are files,, files are files and devices are files. Devices are, usually referred to as a node; however, they are still files., , (execute), , x or 1, , There are also three types of user restrictions:, User, , ls output, , owner, , -rwx------, , group, , ----rwx---, , other, , -------rwx, , The restriction type scope is not inheritable:, the file owner will be unaffected by restrictions, set for his group or everybody else., Folder/Directory Permissions, Directories have directory permissions. The directory, permissions restrict different actions than with files or device, nodes., Permission, , Action, , chmod option, , Read, , (view contents,, i.e. ls command), , r or 4, , Write, , (create or remove, files from dir), , w or 2, , execute, , (cd into directory), , x or 1, , history command, This command shows the commands you have entered, on your terminal so far., , Chmod option, , read, , unix 3 [ ] STREAM CONNECTED 29138, unix 3 [ ] STREAM CONNECTED 29137, , Action, , 1. read restricts or allows viewing the directories contents,, i.e. ls command, 2. write restricts or allows creating new files or deleting, files in the directory. (Caution: write access for a, directory allows deleting of files in the directory even if, the user does not have write permissions for the file!), 3. execute restricts or allows changing into the directory,, i.e. cd command, Folders (directories) must have 'execute' permissions set, (x or 1), or folders (directories) will NOT FUNCTION as, folders (directories) and WILL DISAPPEAR from view in, the file browser (Nautilus)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 95
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Permissions in Action, , Here are a few examples of chmod usage with letters (try, these out on your system)., , $ ls -l /etc/hosts, -rw-r--r-- 1 root root 288 2005-11-13 19:24 /etc/hosts, Using the example above we have the file "/etc/hosts", which is owned by the user root and belongs to the root, group., The permissions from the above /etc/hosts ls output, -rw-r--r-owner = Read & Write (rw-), group = Read (r--), , First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, total 0, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, , other = Read (r--), , Add owner execute bit:, , Changing permissions, The command to use when modifying permissions is, chmod. There are two ways to modify permissions, with, numbers or with letters. Using letters is easier to, understand for most people. When modifying permissions, be careful not to create security problems. Some files are, configured to have very restrictive permissions to prevent, unauthorized access. For example, the /etc/shadow file, (file that stores all local user passwords) does not have, permissions for regular users to read or otherwise access., $ ls -l /etc/shadow, , $ chmod u+x file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod o+wx file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, , -rw-r----- 1 root shadow 869 2005-11-08 13:16 /etc/shadow, , $ chmod g-r file3, , Permissions:, , $ ls -l file3, , owner = Read & Write (rw-), , Add read, write and execute to everyone:, , group = Read (r--), , $ chmod ugo+rwx file4, , other = None (---), , $ ls -l file4, , Ownership:, owner = root, , -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, , group = shadow, , $, chmod with Numbers, , chmod with Letters, Usage: chmod {options} filename, Options, , 96, , -rw----r-- 1 user user 0 Nov 19 20:13 file3, , Definition, , U, , owner, , G, , group, , O, , other, , A, , all (same as ugo), , X, , execute, , W, , write, , R, , read, , +, , add permission, , -, , remove permission, , =, , set permission, , Usage: chmod {options} filename, Options, , Definition, , #--, , owner, , -#-, , group, , --#, , other, , 1, , execute, , 2, , write, , 4, , read, , Owner, Group and Other is represented by three numbers., To get the value for the options determine the type of, access needed for the file then add., For example if need a file that has -rw-rw-rwx permissions, will use the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Owner, read & write, , Group, read & write, , 4+2=6, , Other, read, write & execute, , 4+2=6, , 4+2+1=7, , Another example if you want a file that has --w-r-x--x, permissions you will use the following:, , write, 2, , Group, read & execute, 4+1 = 5, , Other, execute, 1, , $ chmod 251 filename, Here are a few examples of chmod usage with numbers, (try these out on your system)., First create some empty files:, $ touch file1 file2 file3 file4, $ ls -l, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, -rw-r--r-- 1 user user 0 Nov 19 20:13 file3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file4, Add owner execute bit:, $ chmod 744 file1, $ ls -l file1, -rwxr--r-- 1 user user 0 Nov 19 20:13 file1, Add other write & execute bit:, $ chmod 647 file2, $ ls -l file2, -rw-r--rwx 1 user user 0 Nov 19 20:13 file2, Remove group read bit:, $ chmod 604 file3, $ ls -l file3, -rw----r-- 1 user user 0 Nov 19 20:13 file3, Add read, write and execute to everyone:, $ chmod 777 file4, $ ls -l file4, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file4, chmod with sudo, , -rw-r--r-- 1 root root 550 2005-11-13 19:45 /usr/local/bin/, somefile, $ sudo chmod o+x /usr/local/bin/somefile, $ ls -l /usr/local/bin/somefile, -rw-r--r-x 1 root root 550 2005-11-13 19:45 /usr/local/, bin/somefile, $, Recursive permission changes, To change the permissions of multiple files and directories, with one command. Please note the warning in the chmod, with sudo section and the Warning with Recursive chmod, section., Recursive chmod with -R and sudo, To change all the permissions of each file and folder under, a specified directory at once, use sudo chmod with -R, $ sudo chmod 777 -R /path/to/someDirectory, , total 0, , $, , $ ls -l /usr/local/bin/somefile, , $, , $ chmod 667 filename, , Owner, , Please be careful when using sudo!), , $ ls -l, total 3, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rwxrwxrwx 1 user user 0 Nov 19 20:13 file2, Recursive chmod using find, pipemill, and sudo, To assign reasonably secure permissions to files and, folders/directories, it's common to give files a permission, of 644, and directories a 755 permission, since chmod -R, assigns to both. Use sudo, the find command, and a, pipemill to chmod as in the following examples., To change permission of only files under a specified, directory., $ sudo find /path/to/someDirectory -type f -print0 | xargs, -0 sudo chmod 644, user@host:/home/user$ ls -l, total 3, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, drwxrwxrwx 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, To change permission of only directories under a specified, directory (including that directory):, $ sudo find /path/to/someDirectory -type d -print0 | xargs, -0 sudo chmod 755, $ ls -l, , total 3, Changing permissions on files that do not have ownership, of: (Note that changing permissions the wrong way on the, -rw-r--r-- 1 user user 0 Nov 19 20:13 file1, wrong files can quickly mess up the system a great deal!, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 97
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drwxr-xr-x 2 user user 4096 Nov 19 20:13 folder, -rw-r--r-- 1 user user 0 Nov 19 20:13 file2, Warning with Recursive chmod, WARNING: Although it's been said, it's worth mentioning, in context of a gotcha typo. Please note, Recursively, deleting or chown-ing files are extremely dangerous. You, will not be the first, nor the last, person to add one too, many spaces into the command. This example will hose, your system:, $ sudo chmod -R / home/john/Desktop/tempfiles, Note the space between the first / and home.You have, been warned., Changing the file owner and group, A file's owner can be changed using the chown command., For example, to change the foobar file's owner to tux:, $ sudo chown tux foobar, To change the foobar file's group to penguins, you could, use either chgrp or chown with special syntax:, $ sudo chgrp penguins foobar, $ sudo chown :penguins foobar, Finally, to change the foobar file's owner to tux and the, group to penguins with a single command, the syntax, would be:, $ sudo chown tux:penguins foobar, Note that, by default, you must use sudo to change a, file's owner or group., Difference between chown and chgrp, 1) Chown command is used to change ownership as well, as group name associated to different one, where as, chgrp can change only group associated to it., 2) Many people say that regular user only able to use, chgrp to change the group if the user belongs to them., But it's not true a user can use chown and chgrp, irrespective to change group to one of their group, because chown is located in /bin folder so every can, use it with some limited access., umask - Set default permissions, The umask command controls the default permissions, given to a file when it is created., It uses octal notation to express a mask of bits to be, removed from a file's mode attributes., [me@linuxbox ~]$ rm -f foo.txt, [me@linuxbox ~]$ umask, 0002, [me@linuxbox ~]$ > foo.txt, [me@linuxbox ~]$ ls -l foo.txt, -rw-rw-r-- 1 me me 0 2008-03-06 14:53 foo.txt, , we ran the umask command without an argument to see, the current value. It responded with the value 0002 (the, value 0022 is another common default value), which is the, octal representation of our mask. We next create a new, instance of the file foo.txt and observe its permissions., We can see that both the owner and group both get read, and write permission, while everyone else only gets read, permission. The reason that world does not have write, permission is because of the value of the mask., $ rm foo.txt, $ umask 0000, $ > foo.txt, $ ls -l foo.txt, -rw-rw-rw- 1 me me 0 2008-03-06 14:58 foo.txt, When we set the mask to 0000 (effectively turning it off),, we see that the file is now, world writable. To understand how this works, we have to, look at octal numbers again., If we take the mask and expand it into binary, then compare, it to the attributes., Original file mode, , --- rw- rw- rw-, , Mask, , 000 000 000 010, , Result, , --- rw- rw- r--, , Ignore for the moment the leading zeros (we'll get to those, in a minute) and observe that, where the 1 appears in our mask, an attribute was removedin this case, the the world, write permission. That's what the mask does. Everywhere, a 1 appears in the binary value, of the mask, an attribute is unset. If we look at a mask, value of 0022, we can see what it does:, Original file mode, , --- rw- rw- rw-, , Mask 000 000 010 010, Result, , --- rw- r-- r--, , Again, where a 1 appears in the binary value, the, corresponding attribute is unset. Play with some values, (try some sevens) to get used to how this works. When, you're done, remember to clean up:, $ rm foo.txt; umask 0002, The Tar command, The tar (i.e., tape archive) command is used to convert a, group of files into an archive., An archive is a single file that contains any number of, individual files plus information to allow them to be, restored to their original form by one or more extraction, programs. Archives are convenient for storing files as well, as for for transmitting data and distributing programs., Moreover, they are very easy to work with, often much, more so than dealing with large numbers of individual files., , We first removed any old copy of foo.txt to make sure we, were starting fresh. Next,, 98, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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Although tar was originally designed for backups on, magnetic tape, it can now be used to create archive files, anywhere on a file system. Archives that have been created, with tar are commonly referred to as tar balls., Unlike some other archiving programs, and consistent with, the Unix philosophy that each individual program should, be designed to do only one thing but do it well, tar does, not perform compression. However, it is very easy to, compress archives created with tar by using specialized, compression utilities., tar's basic syntax is, tar option(s) archive_name file_name(s), tar has numerous options, many of which are not, frequently used. Unlike many commands, tar requires the, use of at least one option, and usually two or more are, necessary., tar files are created by using both the -c and -f options., The former instructs tar to create an archive and the latter, indicates that the next argument (i.e., piece of input data, in a command) will be the name of the new archive file., Thus, for example, the following would create an archive, file called file.tar from the three files namedfile1, file2 and, file3 that are located in the current directory (i.e., the, directory in which the user is currently working):, tar -cf file.tar file1 file2 file3, It is not absolutely necessary that the new file have the, .tar extension; however, the use of this extension can be, is very convenient because it allows the type of file to be, visually identified. It is necessary, however, that the -f option, be the final option in a sequence of contiguous, singleletter options; otherwise, the system will become confused, as to the desired name for the new file and will use the, next option in the sequence as the name., The -v (i.e., verbose) option is commonly used together, with the -c and -f options in order to display a list of the, files that are included in the archive. In such case, the, above example would become, tar -cvf file.tar file1 file2 file3, tar can also be used to make archives from the contents, of one or more directories. The result is recursive; that is,, it includes all objects (e.g., directories and files) within, each level of directories. For example, the contents of two, directories named dir1 and dir2 could be archived into a, file named dir.tar with the following:, tar -cvf dir.tar dir1 dir2, It is often convenient to use tar with a wildcard (i.e., a, character which can represent some specific class of, characters or sequence of characters). The following, example uses the star wildcard (i.e., an asterisk), which, represents any character or sequence of characters, to, create an archive of every object in the current directory:, tar -cf *, By default, tar creates an archive of copies of the original, files and/or directories, and the originals are retained., , However, they can be removed when using tar by adding, the --remove-files option., As it has no compression and decompression capabilities, of its own, tar is commonly used in combination with an, external compression utility. A very handy feature of the, GNU version (which is standard on Linux) is the availability, of options that will cause standard compression programs, to compress a new archive file as soon as it has been, created. They are -j (for bzip2), -z (for gzip) and -Z (for, compress). Thus, for example, the following would create, an archive named files.tar.bz2 of the files file4, file5 and, file6 that is compressed using bzip2:, tar -cvjf files.tar.bz2 file4 file5 file6, tar can also be used for unpacking tar files. However, before, doing this, there are several steps that should be taken., One is to confirm that sufficient space is available on the, hard disk drive (HDD). Another is to move to an empty, directory (which usually involves creating one with an, appropriate name) to prevent the reconstituted files from, cluttering up the current directory and overwriting any files, or directories with same names that are in it. In addition, if, the archive has been compressed, it must first be, decompressed using the appropriate decompression, program (which can usually be determined by the filename, extension)., In order to unpack a tar file, the -x (for extract) and -f, options are required. It is also common to add the -v option, to provide a running listing of the files being unpacked., Thus, for example, to unpack the archive file.tar created in, a previous example the following would be used:, tar -xvf file.tar, Just as options are available to allow three compression, programs to automatically compress newly created tar, files, the same options can be used to have the, compression programs automatically decompress tar files, prior to extraction. Thus, for instance, the following would, decompress and extract the contents of the compressed, archive files.tar.bz2 that was created in an above example:, tar -xjvf files.tar.bz2, Files can be added to an existing archive using the -r, option. As is always the case with tar, it is also necessary, to use the -f option to indicate that the followingstring (i.e.,, sequence of characters) is the name of the archive. For, example, the following would append a file named file7 to, file.tar:, tar -rf file.tar file7, The --delete option allows specified files to be completely, removed from a tar file (except when the tar file is on, magnetic tape). However, this is different from an, extraction, as copies of the removed files are not made, and placed in the current directory. Thus, for example, the, files file1 and file2 can be removed from file.tar with the, following:, tar -f file.tar --delete file1 file2, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 99
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The -t option tells tar to list the contents of an, uncompressed archive without performing an extraction., Thus, the following would list the contents of file.tar:, tar -tf file.tar, Input, output and error redirection in linux, Input/output redirection means the text that is showing on, the screen while you are running any command(program)in, the shell, that information can be redirect elsewhere and, even it can store this output in a file or can be print directly., This function called Redirection, and can also redirect the, input of program., In Linux systems everything consider as a file., A file descriptor is number that is associated with every, file, When run a program in shell ( i.e when execute a command, ) on the back end Linux access 3 special files., Standard input - 0 file descriptor( example = mouse,), Standard output - 1 file descriptor( example = Screen), Standard error output - 2 file descriptor(example=Screen), So it can redirect these files to other files. If user redirect, standard output (Descriptor = 1) to the printer, instead of, showing these outputs on the screen and the computer, start getting print on paper., Output Redirection, Output Redirection is most commonly used, when execute, a command it's normally appears on the terminal . If extract, any tar file you will notice all the output scrolls down rapidly., And can redirect this output in a file for inspecting the, output or can send anybody via email. This is called Output, Redirection. Using this operator '>' in shell can redirect, the output in a file., Example :, $ ls > output.txt, $ cat output.txt, bin, boot, , root, sbin, selinux, srv, sys, tmp, usr, var, $, If output.txt file is already exit then '>' operator, will overwrite the file for append more output, into output.txt use '>>' instead of '>'., Input Redirection, You can redirect your input by using '<' operator. Cannot, run input redirection on all programs or commands. And, can use only with that programs or commands that accept, Input from keyboard., Example : user going to send an email and already have, Template of that email. and can put template in the email, body using input redirect., $ mail ali < mail_template.txt, above command launch email program with, mail_template.txt contents., Now due to advancement in GUI, and also lots of good, email clients, method is rarely used., Error Redirection, Error Redirection is very helpful when in trouble. In this, case user trying to open a file that is not readable for my, user will get permission denied errors. it will redirect these, error into error.txt file., Example :, $ cat ali.txt 2> /home/H.Ali/error.txt, $ cat /home/H.Ali/error.txt, cat: ali.txt: Permission denied, , etc, , In the above command 2 is descriptor of error redirection, file by typing '2>' you are saying redirect any kind of error, to the file error.txt, , home, , Pipes ' | ' in Linux, , lib, , Linux pipes allow us connect output stream of 'command, a' to input stream of 'command b'. here in my case i will, pipe cat commands output into less as input., , dev, , lib64, lost+found, media, mnt, opt, output.txt, proc, 100, , Example : cat /var/log/messages | less, we can also use pipe for searching strings specially from, large text files., cat /var/log/messages | grep kernal | less, grep is a line searcher it will search lines for specific piece, of text., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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above command will shearch a keywork 'kernel' with grep, and then pipe it again to less., Pipes in linux, A pipe is a form of redirection that is used in Linux and, other Unix-like operating systems to send the output of, one program to another program for further processing., Redirection is the transferring of standard output to some, other destination, such as another program, a file or a, printer, instead of the display monitor (which is its default, destination). Standard output, sometimes abbreviated, stdout, is the destination of the output from command line, (i.e., all-text mode) programs in Unix-like operating, systems., Pipes are used to create what can be visualized as a, pipeline of commands, which is a temporary direct, connection between two or more simple programs. This, connection makes possible the performance of some highly, specialized task that none of the constituent programs, could perform by themselves. A command is merely an, instruction provided by a user telling a computer to do, something, such as launch a program. The command line, programs that do the further processing are referred to as, filters., This direct connection between programs allows them to, operate simultaneously and permits data to be transferred, between them continuously rather than having to pass it, through temporary text files or through the display screen, and having to wait for one program to be completed before, the next program begins., Examples, A pipe is designated in commands by the vertical bar, character, which is located on the same key as the, backslash on U.S. keyboards. The general syntax for, pipes is:, command_1 | command_2 [| command_3 . . . ], This chain can continue for any number of commands or, programs., A very simple example of the benefits of piping is provided, by the dmesg command, which repeats the startup, messages that scroll through the console(i.e., the all-text,, full-screen display) while Linux is booting (i.e., starting, up). dmesg by itself produces far too many lines of output, to fit into a single screen; thus, its output scrolls down the, screen at high speed and only the final screenful of, messages is easily readable. However, by piping the output, of dmesg to the filter less, the startup messages can, conveniently be viewed one screenful at a time, i.e.,, dmesg | less, , The same result could be achieved by first redirecting the, output of dmesg to a temporary file and then displaying, the contents of that file on the monitor. For example, the, following set of two commands uses the output redirection, operator (designated by a rightward facing angle bracket), to first send the output of dmesg to a text file called tempfile1, (which will be created by the output redirection operator if, it does not already exist), and then it uses another output, redirection operator to transfer the output of tempfile1 to, the display screen:, dmesg > tempfile1, tempfile1 > less, However, redirection to a file as an intermediate step is, clearly less efficient, both because two separate, commands are required and because the second, command must await the completion of the first command, before it can begin., The use of two pipes to chain three commands together, could make the above example even more convenient for, some situations. For example, the output of dmesg could, first be piped to the sort filter to arrange it into alphabetic, order before piping it to less:, dmesg | sort -f | less, The -f option tells sort to disregard case (i.e., whether, letters are lower case or upper case) while sorting., Likewise, the output of the ls command (which is used to, list the contents of a directory) is commonly piped to the, the less (or more) command to make the output easier to, read, i.e.,, ls -al | less, or, ls -al | more, ls reports the contents of the current directory (i.e., the, directory in which the user is currently working) in the, absence of any arguments (i.e., input data in the form of, the names of files or directories). The -l option tells ls to, provide detailed information about each item, and the aoption tells ls to include all files, including hidden files, (i.e., files that are normally not visible to users). Because, ls returns its output in alphabetic order by default, it is not, necessary to pipe its output to the sort command (unless, it is desired to perform a different type of sorting, such as, reverse sorting, in which case sort's -r option would be, used)., This could just as easily be done for any other directory., For example, the following would list the contents of the /, bin directory (which contains user commands) in a, convenient paged format:, , less allows the output of dmesg to be moved forward one, ls -al /bin | less, screenful at a time by pressing the SPACE bar and back, The following example employs a pipe to combine the ls, one screenful at a time by pressing the b key. The command, and the wc (i.e., word count) commands in order to show, can be terminated by pressing the q key. (The more, how many filesystem objects (i.e., files, directories and, command could have been used here instead of less;, links) are in the current directory:, however, less is newer than more and has additional, functions, including the ability to return to previous pages, ls | wc -l, of the output.), 101, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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ls lists each object, one per line, and this list is then piped, to wc, which, when used with its -l option, counts the, number of lines and writes the result to standard output, (which, as usual, is by default the display screen)., The output from a pipeline of commands can be just as, easily redirected to a file (where it is written to that file) or, a printer (where it is printed on paper). In the case of the, above example, the output could be redirected to a file, named, for instance, count.txt:, ls | wc -l > count.txt, The output redirection operator will create count.txt if it, does not exist or overwrite it if it already exists. (The file, does not, of course, require the .txt extension, and it could, have just as easily been named count, lines or anything, else.), The following is a slightly more complex example of, combining a pipe with redirection to a file:, echo -e "orange \npeach \ncherry" | sort > fruit, The echo command tells the computer to send the text, that follows it to standard output, and its -e option tells the, computer to interpret each \nas the newline symbol (which, is used to start a new line in the output). The pipe redirects, the output from echo -e to the sort command, which, arranges it alphabetically, after which it is redirected by, the output redirection operator to the file fruit., As a final example, and to further illustrate the great power, and flexibility that pipes can provide, the following uses, three pipes to search the contents of all of the files in, current directory and display the total number of lines in, them that contain the string Linux but not the stringUNIX:, cat * | grep "Linux" | grep -v "UNIX" | wc -l, In the first of the four segments of this pipeline, the cat, command, which is used to read and concatenate (i.e.,, string together) the contents of files, concatenates the, contents of all of the files in the current directory. The, asterisk is a wildcard that represents all items in a specified, directory, and in this case it serves as an argument to cat, to represent all objects in the current directory., The first pipe sends the output of cat to the grep, command, which is used to search text. The Linux, argument tells grep to return only those lines that contain, the string Linux. The second pipe sends these lines to, another instance of grep, which, in turn, with its -v option,, eliminates those lines that contain the string UNIX., Finally, the third pipe sends this output to wc -l, which, counts the number of lines and writes the result to the, display screen., Find hardware devices in Ubuntu Linux with lshw, There are a variety of ways to find out what kind of, hardware running in linux, but one of the easiest ways, that gives a large amounts of valuable data is to use lshw, (Hardware Lister). And lshw is installed by default., Testing of lshw command as shown below…, $ sudo lshw, 102, , Installing, lshw is available on most package management systems., If use APT (Debian-based distros: Ubuntu, Linux Mint, and, others), run the following command in terminal:, $ sudo apt-get install lshw, If use Yum (Red Hat, Fedora, CentOS, Yellow Dog Linux,, etc), run the following command in terminal:, $ sudo yum install lshw, If these instructions don't match your package manager,, look for specific instructions on the lshw site to get it, installed on your system., Using lshw, If you just run lshw by itself on the command line, your, screen will be flooded with large amounts of text., Fortunately, it is very easy to get lshw to give you output, that meets your needs., Shorter output, If you just quickly want to quickly find the chipset version, of a piece of hardware is, you can run the following to, provide a very short output that should give you what you, need:, $ sudo lshw -short, For example, here is a sample when I run this on my Dell, Studio 17 laptop (Note: I've removed a large portion of the, output to make this fit):, $ sudo lshw -short, Device class, , Description, , system, , Studio 1735, , bus, , 0H275K, , memory, , 64KiB BIOS, , processor, , Intel(R) Core(TM)2 Duo CPU, T8100 @ 2.10GHz, , memory, , 32KiB L1 cache, , memory, , 3MiB L2 cache, , memory, , 4GiB System Memory, , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , memory, , 2GiB DIMM DDR Synchronous, 667 MHz (1.5 ns), , display, , Mobility Radeon HD 3650, , multimedia, , RV635 Audio device [Radeon HD, 3600 Series], , multimedia, , 82801H (ICH8 Family) HD, Audio Controller, , eth1 network, , BCM4322 802.11a/b/g/n, Wireless LAN Controller, , eth0 network, , NetLink BCM5784M Gigabit, Ethernet PCIe, , /dev/sda disk, 250GB WDC WD2500BEVS-7, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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This of course leaves out a lot of detail. Maybe we just, need to store the data somewhere so it's easier to work, with., Storing output to a file, If you'd like to put all the lshw output into a file, you can do, so easily from the terminal with output redirection., $ sudo lshw > hardware.txt, This will run the lshw command and put all the output into, a file in the current directory called hardware.txt. Note, that this will replace any file in the current directory called, hardware.txt. Make sure that you either backup the file,, give the output file a unique name, or are prepared to lose, that original file's information., Now you can open the hardware.txt file with your favorite, editor and look through the informations., , Creating HTML or XML Output, lshw has the ability to format its output in either HTML or, XML. This can be very helpful if you want to post your, hardware specs somewhere online to be viewed or to send, the data to a storage system., To create HTML output, simply give lshw the -html, option:, $ sudo lshw -html > hardware.html, This will format the output into a HTML document and, save the output in a file called hardware.html., Creating XML is done with the -xml option:, $ sudo lshw -xml > hardware.xml, Like before, this will output the document in XML format, and save it to hardware.xml., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 103
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Date command examples to display and set, system date time, Date command is helpful to display date in several formats., It also allows you to set systems date and time., Here few examples on how to use date command with, practical examples., When execute date command without any option, it will, display the current date and time as shown below., $ date, Mon May 20 22:02:24 PDT 2013, 1. Display Date from a String Value using -date, Option, If you have a static date or time value in a string, you can, use -d or -date option to convert the input string into date, format as shown below., Please note that this doesn't use the current date and, time value. Instead is uses the date and time value that, you pass as string., The following examples takes an input date only string,, and displays the output in date format. If you don't specify, time, it uses 00:00:00 for time., $ date --date="12/2/2014", Tue Dec 2 00:00:00 PST 2014, , 3. Get Relative Date Using -date option, You can also use date command to get a future date using, relative values., For example, the following examples gets date of next, Monday., $ date --date="next mon", Mon May 27 00:00:00 PDT 2013, If string=@is given to date command, then date command, convert seconds since the epoch (1970-01-01 UTC) to a, date., It displays date in which 5 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@5, Wed Dec 31 16:00:05 PST 1969, It displays date in which 10 seconds are elapsed since, epoch 1970-01-01 UTC:, $ date --date=@10, Wed Dec 31 16:00:10 PST 1969, It displays date in which 1 minute (i.e. 60 seconds) is, elapsed since epoch 1970-01-01 UTC:, $ date --date=@60, Wed Dec 31 16:01:00 PST 1969, , $ date --date="2 Feb 2014", , 4. Display past date, , Sun Feb 2 00:00:00 PST 2014, , You can display a past date using the -date command., Few possibilities are shown below., , $ date --date="Feb 2 2014", Sun Feb 2 00:00:00 PST 2014, The following example takes an input date and time string,, and displays the output in date format., , $ date --date='3 seconds ago', Mon May 20 21:59:20 PDT 2013, $ date --date="1 day ago", , $ date --date="Feb 2 2014 13:12:10", , Sun May 19 21:59:36 PDT 2013, , Sun Feb 2 13:12:10 PST 2014, , $ date --date="yesterday", , 2. Read Date Patterns from a file using -file option, This is similar to the -d or -date option that we discussed, above. But, you can do it for multiple date strings. If you, have a file that contains various static date strings, you, can use -f or -file option as shown below., In this example, we can see that datefile contained 2 date, strings. Each line of datefile is parsed by date command, and date is outputted for each line., $ cat datefile, , $ date --date="1 month ago", Sat Apr 20 21:59:58 PDT 2013, $ date --date="1 year ago", Sun May 20 22:00:09 PDT 2012, 5. Set Date and Time using -set option, You can set date and time of your system using -s or -set, option as shown below.., , Sept 9 1986, Aug 23 1987, , In this example, initially it displayed the time as 20:09:31., We then used date command to change it to 21:00:00., , $ date --file=datefile, Tue Sep 9 00:00:00 PDT 1986, Sun Aug 23 00:00:00 PDT 1987, , 104, , Sun May 19 22:00:26 PDT 2013, , $ date, Sun May 20 20:09:31 PDT 2013, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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$ date -s "Sun May 20 21:00:00 PDT 2013", Sun May 20 21:00:00 PDT 2013, $ date, , The timestamp of datefile is changed using touch command. This was done few seconds after the above date, command's output., $ touch datefile, , Sun May 20 21:00:05 PDT 2013, 6. Display Universal Time using -u option, You can display date in UTC format using -u, or -utc, or universal option as shown below., $ date, Mon May 20 22:07:53 PDT 2013, $ date -u, Tue May 21 05:07:55 UTC 2013, , The current time after the above touch command is, 20:26:12, $ date, Sun May 20 20:26:12 PDT 2013, Finally, use the date command -r option to display the, last modified timestamp of a file as shown below. In this, example, it displays last modified time of datefile as, 20:25:57. It is somewhere between 20:25:48 and 20:26:12, (which is when we execute the above touch command to, modify the timestamp)., , 7. Display Last Modification Time using -r option, , $ date -r datefile, , In this example, the current time is 20:25:48, , Sun May 20 20:25:57 PDT 2013, , $ date, , 8. Various Date command formats, , Sun May 20 20:25:48 PDT 2013, , You can use formatting option to display date command, in various formats using the following syntax:, $ date +%<format-option>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 105
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Command, , Description, , • apropos whatis, , Show commands pertinent to string. See, also threadsafe, , • man -t ascii | ps2pdf - > ascii.pdf, , make a pdf of a manual page, , which command, , Show full path name of command, , time command, , See how long a command takes, Start stopwatch. Ctrl-d to stop. See also, sw, , • time cat, dir navigation, • cd -, , Go to previous directory, , • cd, , Go to $HOME directory, , (cd dir && command), , Go to dir, execute command and return to, current dir, Put current dir on stack so you can popd, back to it, , • pushd ., file searching, • alias l='ls -l --color=auto', , quick dir listing. See also l, , • ls -lrt, , List files by date. See also newest and, find_mm_yyyy, , • ls /usr/bin | pr -T9 -W$COLUMNS, , Print in 9 columns to width of terminal, , find -name '*.[ch]' | xargs grep -E 'expr', , Search 'expr' in this dir and below. See, also findrepo, , find -type f -print0 | xargs -r0 grep -F 'example', , Search all regular files for 'example' in, this dir and below, , find -maxdepth 1 -type f | xargs grep -F, 'example', , Search all regular files for 'example' in, this dir, , find -maxdepth 1 -type d | while read dir; do, echo $dir; echo cmd2; done, , Process each item with multiple, commands (in while loop), , • find -type f ! -perm -444, , Find files not readable by all (useful for, web site), , • find -type d ! -perm -111, , Find dirs not accessible by all (useful for, web site), , • locate -r 'file[^/]*\.txt', , Search cached index for names. This re is, like glob *file*.txt, , • look reference, , Quickly search (sorted) dictionary for, prefix, , • grep --color reference /usr/share/dict/words, , Highlight occurances of regular, expression in dictionary, , archives and compression, gpg -c file, , Encrypt file, , gpg file.gpg, , Decrypt file, , tar -c dir/ | bzip2 > dir.tar.bz2, , Make compressed archive of dir/, , bzip2 -dc dir.tar.bz2 | tar -x, , Extract archive (use gzip instead of bzip2, for tar.gz files), , tar -c dir/ | gzip | gpg -c | ssh user@remote 'dd Make encrypted archive of dir/ on remote, of=dir.tar.gz.gpg', machine, , 106, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished
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set operations (Note you can export LANG=C for speed. Also these assume no, duplicate lines within a file), sort file1 file2 | uniq, , Union of unsorted files, , sort file1 file2 | uniq -d, , Intersection of unsorted files, , sort file1 file1 file2 | uniq -u, , Difference of unsorted files, , sort file1 file2 | uniq -u, , Symmetric Difference of unsorted files, , join -t'\0' -a1 -a2 file1 file2, , Union of sorted files, , join -t'\0' file1 file2, , Intersection of sorted files, , join -t'\0' -v2 file1 file2, , Difference of sorted files, , join -t'\0' -v1 -v2 file1 file2, , Symmetric Difference of sorted files, , math, • echo '(1 + sqrt(5))/2' | bc -l, , Quick math (Calculate φ). See also bc, , • seq -f '4/%g' 1 2 99999 | paste -sd-+ | bc -l, , Calculate π the unix way, , •, , echo 'pad=20; min=64;, (100*10^6)/((pad+min)*8)' | bc, , More complex (int) e.g. This shows max, FastE packet rate, , •, , echo 'pad=20; min=64; print, (100E6)/((pad+min)*8)' | python, , Python handles scientific notation, , •, , echo 'pad=20; plot [64:1518], (100*10**6)/((pad+x)*8)' | gnuplot -persist, , Plot FastE packet rate vs packet size, , • echo 'obase=16; ibase=10; 64206' | bc, , Base conversion (decimal to, hexadecimal), , • echo $((0x2dec)), , Base conversion (hex to dec) ((shell, arithmetic expansion)), , • units -t '100m/9.58s' 'miles/hour', , Unit conversion (metric to imperial), , • units -t '500GB' 'GiB', , Unit conversion (SI to IEC prefixes), , • units -t '1 googol', , Definition lookup, , • seq 100 | paste -s -d+ | bc, , Add a column of numbers. See also add, and funcpy, , calendar, • cal -3, , Display a calendar, , • cal 9 1752, , Display a calendar for a particular month, year, , • date -d fri, , What date is it this friday. See also day, , •, , [ $(date -d '12:00 today +1 day' +%d) = '01' ], || exit, , exit a script unless it's the last day of the, month, , • date --date='25 Dec' +%A, , What day does xmas fall on, this year, , • date --date='@2147483647', , Convert seconds since the epoch (197001-01 UTC) to date, , • TZ='America/Los_Angeles' date, , What time is it on west coast of US (use, tzselect to find TZ), , •, , date --date='TZ="America/Los_Angeles" 09:00, next Fri', , What's the local time for 9AM next Friday, on west coast US, , locales, • printf "%'d\n" 1234, , Print number with thousands grouping, appropriate to locale, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.5.27 - 1.5.28, , Copyright @ NIMI Not to be Republished, , 109
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.29, , MS WORD 2010 THEORY, Objectives : At the end of this lesson you shall be able to, • state what is MS Office, • brief what is MS Word and starting steps, • explain various screen blocks of MS Word, • explain procedures to create, save, print a documentl., Microsoft office is a application software package, introduced by Microsoft Corporation. MS Office consists, of the following popular packages :, , The Ribbon tab of Word has eight major parts viz. File,, Home, Insert, Page Layout, References, Mailings,, Review and View., , •, , Microsoft Word, , •, , Microsoft Excel, , •, , Microsoft Powerpoint, , •, , Microsoft Access, , •, , Microsoft Outlook, , File tab of the ribbon is useful to create a new file, a, blank or a template page as required. Ctrl + N always, create a new blank document in Office Package. The, documents so created can be saved as default word, document or given compatible format. Furthermore,, permission for accessing a documents can be fixed,, share a document on a network, even manage a, document to be compatible with previous and external, versions. Print option makes the document to get a hard, copy or a pdf format according to the installed printer, features. Recently opened files can also be viewed to, find it easy to work again. Help on word is there in the, same tab., , Word 2010, It is a word processor package that helps to create and, edit a document. It is the most known word processor of, nowadays. It makes professional looking documents by, providing a comprehensive set of tools for creating and, formatting a document, memos, letters, reports,, brochures, business documents and even internet web, pages., Starting Word, , Fig. 2 Home Tab, , Fig 2, , Fig 1 - Default page layout, , Copa 1182902, , Click on the Start > (windows Logo) All programmes >, Microsoft office > Microsoft Word. MS Word opens along, with a default blank document with default settings page, layout., , Home tab has clipboard options including cut, copy, paste, and paste special. The Font block has all the options of, setting fonts, size, superscript, subscript, bold, italic,, underline, strikethrough, font colors, etc., , Fig 1, , Fig 3 - Paragraph Group, , Unlike previous version, MS Office 2010 has a common, set of features for all the components. It makes it easy, to understand and common utilities to remain available, on all the packages of MS Office including Word, Excel,, PowerPoint, Access, etc. Many features are redesigned, so as enabling the diverted users of other packaged can, afford with. These enhancements and utilities in Word, 2010 are described as below., , Copa 1182903, , Copa 1182901, , Fig 3, , Paragraph group creates the formatting paragraphs with, alignments left, right, center, justify and indentations, para, and line spacing. Line and page breaks allows to create, pagination options and exceptions of formatting., , Copyright @ NIMI Not to be Republished, , 113
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Fig 4 - Styles and Editing Group, , Symbols group inserts symbols of equations like math, equations or symbols like currency, math symbols, etc., Copa 1182904, , Fig 4, , Fig 8 - Themes and Page Setup Group, , Fig 8, , Copa 1182905, , Fig 5, , Page group makes cover pages, blank pages insertion, and page breaks. Tables group helps to insert a table in a, text document with ready specified row-column set or a, customized table format. Illustration group inserts pictures, from external sources, cliparts, shapes, smart art, charts, of data, even screenshot into the text document., Fig 6 - Links and Header/Footer Groups, , Page Layout tab has five major groups. Themes block, creates predefined template setup using themes on, documents. Even new themes customized can be, created and saved for future use., Page setup group has features on margin around, page, orientation i.e. vertical or horizontal, paper size, columns, to display, breaks, line numbers and hyphenation., Fig 9 - Page Background and Paragraph Group, Fig 9, Copa 1182909, , The Insert tab has 7 groups. Fig 5 - Pages, Tables and, Illustrations blocks (Fig 5), , Copa1182908, , The Styles group allows preformatted text styles like, Heading styles, Paragraph styles, Subtitles, etc. Custom, styles can also be stored with altered specifications. The, Editing group used to select specific area, find and / or, replace option in a specified area in text., , Page Background group creates a watermark, page, Background color and page borders. Paragraph block, has specified options already discussed in Home ->, Paragraph group., Copa1182906, , Fig 6, , Fig 10 - Arrange Group, , Fig 10, Copa 11829010, , Links group creates hyperlink on texts, bookmarks and, cross references in a document., The header and footer group inserts header, footer to be, appearing on every page and page numbers to display, as to placement area., , The arrange group creates position of objects, text, elements, text wrapping, arranging objects, aligning of, objects, grouping and transformations., , Fig 7 - Text and Symbols block, , Fig 7, , References tab has six blocks., , Text group allows creating text box, quick parts likely to, create brochures, designed text as WordArt, paragraph, styles, a signature line, date and time and an object insert, option., 114, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , Copa 11829011, , Fig 11, , C, , 1182907, , Fig 11 - TOC and Footnotes Group
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Fig 15 - Write and Insert fields Group, , Fig 15, Copa 11829015, , Table of contents creates the TOC of a particular, publication document automatically and upon, modifications updatable. Footnotes tab creates footnotes, of a page, block area which includes explanatory phrases, or references. Endnote makes the note at the end of the, document., Fig 12 - Citations, Bibilography and Captions Group, , Copa 11829012, , Fig 12, , Citation and Bibliography makes an external source as, citation, reference tables and credits of authors related, to the publication. Captions tab inserts a caption, table, of figures, cross references inside a text., , While writing a letter, it has many parts, which this mail, merge creates fields of Address Block, Greetings Line,, Merged field of content, labels, etc., Fig 16 - Preview Results and Finish Groups, Fig 16, , Copa 11829016, , Fig 13 - Index and Table of Authorities Group, , Copa 11829013, , Fig 13, , Index enters a value on a main topic or sub topic and, create the index accordingly. Table of authorities has, the citation mark includes the list of the cases, statutes, and other authorities cited in the document., , On successful completion of mail merge, it can be, previewed and checked for errors for each recipients, and edit accordingly. Upon validation the mail merge, gets finished., Fig 17 - Proofing and Language Groups, Fig 17, , Fig 14 - Create and Mailmerge Groups, , Mailings tab used to create mailing of a letter or order, using common mailing features. Create block makes, envelopes print using predefined formats as well as, custom formats. Labels can also be printed to which the, delivery address is mentioned., Mail merge block is used to create mail merge of a letter,, email. If a common letter is created and to be sent to, many recipients, this option allows to create an Address, block where the recipient's info should appear. Even, selective recipients can be listed as well as a new, recipient list can be created., , Copa 11829017, , Copa 11829014, , Fig 14, , Review tab here is used for the various document areas, to be reviewed. Proofing makes easier to check Spelling, and Grammar of a document. Accidental errors can be, corrected here. Research refines the search not only, inside the document, but also the referenced documents., Thesaurus identifies the completeness of the document, using the standard language compatibility of the region, like English UK or English USA etc. Word count shows, the analysis of the document as total words, total, characters, with and without spaces, no. of paragraphs,, lines, etc. Here Text blocks can also be included for, such analysis., Language Block helps to translate a page into the, installed other languages and to change the proofing, language. It requires the direct translator service from, Microsoft Online., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished, , 115
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Fig 18 - Comments & Tracking Group, , Fig 20 - Document views and show Groups, , Fig 18, , Comments group inserts a comment for a specific, paragraph or text block., Tracking group finds the changes made on a document, by other authors in a protected mode. For example, if a, document is created by user X and edited by user Y, is, tracked separately with Track marks., Fig 19 - Changes, Compare and Protect Groups, , Copa 11829020, , Copa 11829018, , Fig 20, , View tab shows the way of displaying the word document., Document views have a Print Layout, a common view, of Word, Full Screen Reading, minimises the tabs and, ribbons to disappear and easy to read, Web Layout, which, previews a html compatible view, Outline, views the basic, version of document in mere text mode and Draft mode, for a text editing mode., The Rulers, Gridlines and Navigation Pane can be shown, or hidden according to user preferences., Fig 21 - Zoom / Window / Macro Groups, , Fig 19, , Changes hence made on the documents can either then, accepted or rejected. More than a document can be, compared for similarity using Compare. Also the, document can be protected from editing by other authors., , 116, , Copa 11829021, , Copa 11829019, , Fig 21, , Also the view of the page can be Zoomed to full page, two, pages view, 100% of the document and custom view. To, make easy editing a document the window can be split, into two, a new window for a document to cut paste, etc., can be created and all open word documents can be, arranged for view. While formatting the documents, for, repetition of commands the Macro option can be used. It, uses the Record option to store the set of commands and, repeat it again on other part of document or on another, document on a single click., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.29, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.6.30 to 1.6.37, COPA- Word Processing Software, Creating a file, save and other options, Objectives: At the end of this lesson you shall be able to, • explain how to create a new document, save and print, • state how to edit, format text and document styles, • brief using tables inside word document with data, • explain how to create styles in a document and save for future use, • explain Few unique features of Word 2010, • brief the mail merge processing, Fig 1 - File Info view, , Fig 3 - Print options in word, , Fig 1, Fig, 22, , Fig 3, , Copa 11829024, , Copa 11829022, , Fig 24, , Word 2010 new document can be created as usual with, Ctrl + N or through File menu New option. Basically the, file created is saved as a word document extended format, as docx in word file., Fig 2 - Save options in Word, , The saved documents can be printed using the File Menu, -> Print option and the installed printer support makes it, easy to get the document printed. If Adobe Acrobat, Professional is installed, the same document can be, stored as a PDF file for sharing purposes. Apart from, printing and storage, the file created can be published in, web as a web page or template that can be used for, future publications in same format., , Copa 11829023, , Fig 23, 2, Fig, , It can be saved using save as option in any compatible, format or old versions of office, like 2003 or earlier versions., Main utility of the word software is the creation of word, processing documents. It may be any of a format like, publication, letter, brochure, etc. Word supports all type, of formatting to design a text based presentation. Also it, supports output files in major accepted formats according, to industry standards., , Basic concepts to be noted while using Word are Text, properties. It includes Font type, Font size, Text Color,, and usual decorations of text. Also creating of paragraphs, styles are to be kept in mind. Paragraph alignment has, left, right, center and justified settings. Text elements, may contain items like ordered list, unordered list, subsection lists. They are found there paragraph formatting, block of Home Tab. Indenting of text for creating Quotes, is also there inside the same tab. According to the page, size, line spacing and paragraph spacing can be adjusted,, like before and after paragraph spaces, line heights, etc., The Styles can be predefined to use as ready to put on, places where it required. Standard templates are, available but it allows to create custom styles too., Tables can be inserted for various utilities. Normal table, has adjustable width and columns so it can simply inserted, with Insert > Table option directly., , Copyright @ NIMI Not to be Republished, , 117
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Fig 4 - Table insert wizard options, , FigFig, 276, , Fig 4, , In case of custom sized table is required, it can be created, using insert table / draw table options. Insert table allows, custom values for columns, width and other properties., Draw table creates custom table using a pen drawing tool, through which new table can be drawn according to the, available text contents., Customizable Quick Access Tool Bar, Word 2010's Quick Access Toolbar displays all the, commonly used options. It is located in the top left side, corner of the application window, near the office button., By default it displays the following three options, Save,, Undo and Redo, but is customizable and you may easily, add more options to it. (Fig 5), , Navigation Pane, In the previous versions of Microsoft Office, one has to, use the Ctrl+F hotkey to find any word or phrase from, within a document. Word 2010 has added a new magic to, this option, Ctrl+F now summons a Navigation Pane that, appears on the left side of the document. You will see the, three views available by clicking on their respective tabs,, the Heading View, Thumbnail Page View, and the Search, Result View. (Fig 7), Fig 7, , Fig 28, , Fig 26, , Copa 11829026, , Copa 11829028, , Fig 5, , Copa 11829027, , Copa 11829025, , Fig 25, , Paste Preview, , Customizable Ribbon Button, Apparently the Ribbon button in Word 2010 looks like the, one in Word 2007. But there is one big addition, you may, customize the word 2010's Ribbon button. In order to, customize the Ribbon button navigate to the following option, Office Button > Word Option > Customize Ribbon. (Fig 8), , It happens with most users that after copying and pasting, something into their document, they need to undo the, some changes. Word 2010 has made it easy for users,, now you may eliminate this unnecessary step by using, the paste preview option. It allows users to paste only the, values or the formatting. (Fig 6), 118, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished
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Improved Collaborations, , 8, FigFig29, , Copa 11829029, , Microsoft Word 2010 has a new feature called coauthoring. It allows more than one authors to edit a, document at the same time. Word 2010 tells you how, many authors are editing the document and their changes, can be viewed too. (Fig 9), , Fig 9, , Copa 11829030, , Fig 30, , Screen Capture Tool, , Copa 11829032, , Fig 10, Fig 31, , Fig Fig, 32 11, , Copa 11829031, , Word 2010 includes a feature called Screen Capturing,, now there is no need to use a third party or additional tool, to capture a screenshot in order to use it in Word, just, simply use Word 2010's built in tool to capture any area of, the screen. A Screenshot may be taken by navigating to, the following option Insert > Screenshot. (Fig 10), , The Background Removal Option, Artistic Effects, In Word 2010 users can now apply a number of snazzy, artistic effects to the pictures. In order to add the artistic, effects to your document, Navigate to the following option, Insert > Illustrations > Picture. Then browse and select, the picture you want, Once the picture is added to your, document, then the Picture Tools contextual tab is, displayed and you will be able to see the new Artistic, Effects drop down button over here. (Fig 11), , Office 2010 has an awesome option by the name of, Background Removal, which simply removes the, background of any image. Yes, you don't need Photoshop, anymore to remove the background. First insert the, picture in your Word document from the Insert > Picture, option. Then locate the Background Removal tool and get, rid of the background. (Fig 12), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 119
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Ligatures, , Copa 11829033, , Fig33, 12, Fig, , You might have heard about Ligatures. They make the, fonts look fancy and they are also used to keep letters, separate allowing you to search the text as if the font, were regular. Its true that not all fonts support ligatures,, but a large variety of the fonts supports them. You may, enable them from Font Preferences > advanced, then select, the standard only option in the ligatures drop down box., (Fig 15), Fig 15, , Fig 36, , Office Backstage, The Office Backstage is a new concept, it is the enhanced, form of the plain old office button and provides a much, user-friendly menu. It helps users to manage documents,, presentations, or spreadsheets at a greater level. (Fig 13), , Interesting feature, right? Read more about it here., , Copa 11829036, , Copa 11829034, , Fig Fig, 3413, , Improved Spell Checks, Word 2010 has added some new features to its spell, checker, now it will detect the mistake and suggest, changing the sentence., , Fig, Fig 16, , New Art Effects in WordArt, , 37, , Just like other features, WordArt has been updated with, new colorful art effects. Select the text, then click Word, Art and a list of all the available options will be displayed., (Fig 14), , 120, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , Copa 11829037, , Fig 35, , Copa 11829035, , Fig 14
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Shortcut keys in Word 2010, Objective : at the end of the lesson you shall be able to, •, , Learn the shortcut keys in MS Word., CTRL+SHIFT+A, , converts the selected text to capital letters or vice versa, , CTRL+SHIFT+F, , Displays the Font dialog box., , CTRL+SHIFT+G, , Displays the Word Count dialog box., , CTRL+SHIFT+S, , Displays the Apply Styles task pane., , ALT+R, , Displays the Review tab, , ALT+CTRL+1, , Apply Heading 1, Similarly ALT + CTRL + 2 will apply heading 2, , CTRL+SHIFT+L, , Applies Bullets, , CTRL+SHIFT+F5, , Bookmark, , CTRL + B, , Bold Text, , CTRL + I, , Italic Text, , CTRL + U, , Underline Text, , CTRL+PAGE DOWN Browse Next, CTRL+E, , Navigate to the center Paragraph, , CTRL+SHIFT+ENTER, , Column Break, , CTRL+SHIFT+C, , Copy Format, , ALT+SHIFT+F7, , Dictionary, , ALT+CTRL+S, , Splits the Document, , CTRL+SHIFT+D, , Double Underline, , CTRL+END, , End of Document, , END, , End of line, , CTRL+SHIFT+P, , Font size select, , SHIFT+F5 or ALT+CTRL+Z, , Go Back to previous state, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.6.30 - 1.6.37, , Copyright @ NIMI Not to be Republished, , 121
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IT & ITES, COPA - Word Processing Software, , Related Theory for Exercise 1.6.38, , Typing practice using open source typing tutor tools, Objectives : At the end of this lesson you shall be able to, • understand about typing software, • typing Tutor tools., You will be able to learn touch typing quickly and efficiently, with the program's intelligent practice lessons, useful, support functions and an extensive progress tracker. You, can also play a typing game and expand the program with, open lessons or make your own to meet your specific, needs., , The Typing Tutor Advantage, , Full courses for Beginner, Advanced and Expert typists, , •, , •, , Introduction course. First time using keyboard. The, course covers all characters typed on your keyboard., , •, , Beginner course. This course helps to learn the position, of keys on the keyboard. After completing this course,, you will know which finger to use to hit each key without, looking at the keyboard. The course also covers uppercase letters, special symbols, and the numeric pad., , •, , •, , Create classes to group your students, and Import, your entire student roster using our simple Student, Import tool., , •, , Statistical Graphs & Charts, Both students and teachers have access to detailed, graphs and statistics to track progress., , •, , Complete Course - Novice to Professional, Beginner, Intermediate, Advanced, and Specialty, Lessons to help typists of all levels., , •, , Fun Interactive Typing Games, Students can take a break from the exercises to, practice with several educational typing games., , Progress Tracking, The statistics reflect your typing speed, accuracy and, time-out, complete with a summary at the end of each, lesson., , •, , •, , and it suggests your next step: Go to the next lesson, or Try again comparing the results with Course goals., , •, , •, , You can evaluate your own performance or students at, any time by simply looking at charts., , •, , overall lesson rate, typing speed( WPM, CPM, KPM,, WPS, CPS, KPS ), accuracy and time-out are enabled, in the both: table and chart presentation, , •, , also, for each lesson, statistics by each character and, keystroke in the column charts, , •, , Reporting, Access and export detailed reporting data. Reports, and graphs exist for all levels of data., , Advanced course, helps to improve your typing speed, by memorizing frequently used syllables and words., Expert course helps you to perfect the skills acquired, by typing an actual text., , Easy to Get Started, , Typing Test, Students can repeat the typing test to track their, progress over time., Helpful Typing Hints & Tips, Tips and helpful technique information is constantly, provided to reinforce proper typing techniques., , •, , On-Screen Keyboard & Hand Diagram, Key position and proper finger placement is always, displayed to keep beginners from looking at their, hands., , Copyright @ NIMI Not to be Republished, , 123
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IT & ITES, Related Theory for Exercise 1.7.39 to 1.7.41, COPA - Spread Sheet Application, Introduction to MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Features & Functions of Microsoft Excel, Whether for work or home use, an Excel spreadsheet is, the best tool in Microsoft Office for organizing data and, making lists. Although Word documents can include, tables and columns, Excel makes laying out information, for easier. Excel also has a range of functions for designing, formulas that automate calculations. Although Excel looks, intimidating at first, the program's layout is similar to other, Office applications., Cells and Worksheets, The main portion of Excel's window consists of a, spreadsheet -- or worksheet of cells. Just as with a paper, spreadsheet, each cell can contain any numbers or any, text -- unlike working with an Access database, Excel, allows to simply click on any cell and fill it however best, fits the project., In some cases, such as to track spending, if want to use, an organized series of rows and columns. Other times,, such as building a list of team members, cell order and, positioning won't play a major role. One advantage to, Excel is how simple it makes reorganizing data: select a, cell and drag its border to move it to a new spot on the, sheet., Excel Workbooks, Every Excel file, called a workbook, contains one or more, worksheets. To switch between sheets in a workbook,, use the tabs in the lower left corner of the window. Since, Excel 2010, most workbooks use the file extension XLSX,, , 124, , whereas older versions used XLS files. New copies of Excel, can read these old files, but to open a new workbook in an, old edition, the old PC needs the Office compatibility pack., Formulas and Functions, In addition to containing plain text and numbers, cells, can contain formulas, which always start with an equals, sign. With a formula, Excel displays the result of an, equation in a cell, but automatically keeps that result, up-to-date as you change its components. A basic formula, can take the place of a calculator: write "=2+4" and Excel, displays "6." Formulas also work with data in other cells:, "=A1+B1" adds the values of cells A1 and B1., For procedures other than direct arithmetic, use functions, to perform various operations on data. Functions' abilities, range from simple math, such as "AVERAGE" to average, a range of cells, to modifying text, such as "LOWER" to, convert a line to lower case., The two terms are often confused, but remember that, each cell can contain only one formula, but each formula, can use multiple functions, such as "=AVERAGE(A1,, B1)+SUM(A2, B2)" to add the sum of two cells to the, average of two other cells., The following basic window appears when you start the, excel application. Let us, now understand the various important parts of this window, as shown in fig-1., Ribbon Tabs, , Copyright @ NIMI Not to be Republished
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Copa 1203901, , Fig 1, , As with the rest of Office since 2007, Microsoft has, replaced Excel's menus with ribbon tabs as shown in, fig-2. The tab as visual menus that remain open each, tab contains a set of related features with explanatory, icons. For example, the Home tab contains the most, common options, such as font and text color, while the, Insert tab offers ways to insert tables, text boxes and, charts. One tab, File, behaves differently. File still, contains basic tasks including "New," "Open" and "Save,", but displays these tasks in a full-screen area with extra, options, called the backstage view. For example, the, "New" button in the backstage view offers a searchable, selection of templates for new workbooks., , Fig 2, , Copa 1203902, , Ribbon contains commands organized in three, , components:, Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert, Page, Layout is the examples of ribbon tabs., Groups: They organize related commands; each group, name appears below the group on the Ribbon. For, example, group of commands related to fonts or group, of commands related to alignment etc., ?Home: Use this tab when creating, formatting, and, editing a spreadsheet., This tab is arranged into the Clipboard, Font, Alignment,, Number, Styles, Cells, and Editing groups., , Insert: Use this when adding particular elements (including, graphics, PivotTables, charts, hyperlinks, and headers and, footers) to a spreadsheet. This tab is arranged into the, Tables, Illustrations, Sparkline, Filter, Charts, Links, and, Text groups., Page Layout: Use this tab when preparing a spreadsheet, for printing or reordering graphics on the sheet. This tab, is arranged into the Themes, Page Setup, Scale to Fit,, Sheet Options, and Arrange groups., Formulas: Use this tab when adding formulas and, functions to a spreadsheet or checking a worksheet for, formula errors. This tab is arranged into the Function, Library, Defined Names, Formula Auditing, and, Calculation groups. Note that this tab also contains a, Solutions group when activate certain add-in programs,, Data: Use this tab when importing, querying, outlining,, and subtotaling the data placed into a worksheet's data, list. This tab is arranged into the Get External Data,, Connections, Sort & Filter, Data Tools, and Outline, groups., Review: Use this tab when proofing, protecting, and, marking up a spreadsheet for review by others. This tab, is arranged into the Proofing, Language, Comments, and, Changes groups. Note that this tab also contains an Ink, group with a sole Start Inking button if you're running, Office 2010 on a Tablet PC or on a computer equipped, with some sort of electronic input tablet., View: Use this tab when changing the display of the, Worksheet area and the data it contains. This tab is, arranged into the Workbook Views, Show, Zoom,, Window, and Macros groups., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 125
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Title Bar, , Status Bar, , This lies in the middle and at the top of the window. Title, bar shows the program and the sheet titles., , This displays the sheet information as well as the insertion, point location. From left to right, this bar can contain the, total number of pages and words in the document,, language etc., , Help, The Help Icon can be used to get excel related help, anytime you like. Thisprovides nice tutorial on various, subjects related to excel., Zoom Control, Zoom control lets to zoom in for a closer look at your, text. The zoom control consists of a slider that user can, slide left or right to zoom in or out. The + buttons can be, clicked to increase or decrease the zoom factor., View Buttons, The group of three buttons located to the left of the Zoom, control, near the, bottom of the screen, lets to switch among excel's various, sheet views., Normal Layout view: This displays the page in normal, view., , user can configure the status bar by right-clicking, anywhere on it and byselecting or deselecting options, from the provided list, File Tab, The File tab replaces the Office button from Excel 2010., user can click it to check the Backstage view, where, user come to open or save files, create new sheets, print, a sheet, and do other file-related operations., Quick Access Toolbar, TheFile tab and its purpose is to provide a convenient, resting place for the Excel's most frequently used, commands. And customize this toolbar based on the, comfort., Dialog Box Launcher(Fig-3), , Page Layout view: This displays pages exactly as they, will appear when printed. This gives a full screen look of, the document., , This appears as a very small arrow in the lower-right, corner of many groups on the Ribbon. Clicking this button, opens a dialog box or task pane that providesmore, options about the group., , Page Break view: This shows a preview of where pages, will break when printed., , If already have an opened sheet then it will display a, window showing the, , Sheet Area, , details about the opened sheet as shown fig-4. Backstage, view shows threecolumns when select most of the, available options in the first column., , The area where to enter data. The flashing vertical bar, is called the insertion point and it represents the location, where text will appear when type., Row Bar, , Fig 3, , Rows are numbered from 1 onwards and keeps on, increasing as to keepentering data. Maximum limit is, 1,048,576 rows., Columns are numbered from A onwards and keeps on, increasing as to keep, entering data. After Z, it will start the series of AA, AB, and so on. Maximum limit is 16,384 columns., First column of the backstage view will have the following options as shown in, Table-1:, Option, , Description, , Save, , If an existing sheet is opened, it would be saved as is,otherwise it will display a dialogue, box asking for thesheet name., , Save As, , A dialogue box will be displayed asking for sheet nameand sheet type. By default, it will, save in sheet 2010 format with extension .xlsx., , Open, , This option is used to open an existing excel sheet., , Close, , This option is used to close an opened sheet., , Info, , This option displays the information about the openedsheet., , 126, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , Copa 1203903, , Column Bar
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Option, , Description, , Recent, , This option lists down all the recently opened sheets., , New, , This option is used to open a new sheet., , Print, , This option is used to print an opened sheet., , Save & Send, , This option saves an opened sheet and displays options to send the sheet using email etc., , Help, , You can use this option to get the required help about excel 2010., , Options, , Use this option to set various option related to excel 2010., , Exit, , Use this option to close the sheet and exit., , Sheet Information, When click Info option available in the first column, it, displays the following information in the second column, of the backstage view:, , Fig 5, , Compatibility Mode: If the sheet is not a native excel, 2007/2010 sheet, a Convert button appears here,, enabling to easily update its format. Otherwise, this, category does not appear., Permissions: This option used to protect the excel sheet., And can set a password so that nobody can open the, sheet, or lock the sheet so that nobody can edit the sheet., , Versions: If the sheet has been saved several times,, and may be able to access previous versions of it from, this section., Sheet Properties, When click Info option available in the first column, it, displays various properties in the third column of the, backstage view. These properties include sheet size, title,, tags, categories etc., user can also edit various properties. Just try to click on, the property value and if property is editable, then it will, display a text box where can add the text like title, tags,, comments, Author., , Copa 1203905, , Prepare for Sharing: This section highlights important, information should know about the sheet before send it, to others, such as a record of the edits the made as, developed the sheet., , Sheet area is the place of type the text. The flashing vertical, bar iscalled the insertion point and it represents the location, where text will appearwhen type. When click on a box, then the box is highlighted. When double click the box,, the flashing vertical bar appears and can start entering the, data., So, just keep the mouse cursor at the text insertion point, and start typing whatever text would like to type. We, have typed only two words "HelloExcel" as shown fig-6., The text appears to the left of the insertion point., Fig 6, , Entering values, , Copa 1203906, , A new sheet is displayed by default when open an excel, sheet as shown in the fig-5 screen shot., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 127
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There are following three important points, which would help while typing:, • Press Tab to go to next column., •, , Press Enter to go to next row., , •, , Press Alt + Enter to enter a new line in the same, column., , Move Around in Excel 2010, Excel provides a number of ways to move around a sheet, using the mouse and the keyboard., , First of all, let us create some sample text before we, proceed. Open a new excel sheet and type any data. A, sample data table as shown table-2 and fig-7., , OrderDate, , Region, , Rep, , Item, , Units, , Unit Cost, , Total, , 1/6/2010, , East, , Jones, , Pencil, , 95, , 1.99, , 189.05, , 1/23/2010, , Central, , Kivell, , Binder, , 50, , 19.99, , 999.5, , 2/9/2010, , Central, , Jardine, , Pencil, , 36, , 4.99, , 179.64, , 2/26/2010, , Central, , Gill, , Pen, , 27, , 19.99, , 539.73, , 3/15/2010, , West, , Sorvino, , Pencil, , 56, , 2.99, , 167.44, , 4/1/2010, , East, , Jones, , Binder, , 60, , 4.99, , 299.4, , 4/18/2010, , Central, , Andrews, , Pencil, , 75, , 1.99, , 149.25, , 5/5/2010, , Central, , Jardine, , Pencil, , 90, , 4.99, , 449.1, , 5/22/2010, , West, , Thompson, , Pencil, , 32, , 1.99, , 63.68, , 6/8/2010, , East, , Jones, , Binder, , 60, , 8.99, , 539.4, , 6/25/2010, , Central, , Morgan, , Pencil, , 90, , 4.99, , 449.1, , 7/12/2010, , East, , Howard, , Binder, , 29, , 1.99, , 57.71, , 7/29/2010, , East, , Parent, , Binder, , 81, , 19.99, , 1,619.19, , 8/15/2010, , East, , Jones, , Pencil, , 35, , 4.99, , 174.65, , Moving with Mouse, , Table-2, , Mouse can easily move the insertion point by clicking in, the text anywhere on the screen. Sometime if the sheet, is big then user cannot see a place need to move. In, such situations, to use the scroll bars, as shown fig-8, screen shot., , Copa 1203907, , Fig 7, , 128, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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User can move box by box or sheet by sheet. Now click, in any box containing data in the sheet. It would have to, hold down the Ctrl key while pressing an arrow key, which, moves the insertion point as described here -, , Fig 8, , Copa 1203908, , Key Combination, , Where the Insertion Point, Moves, , Ctrl +, , Î, , To the last box containing data, of the current row., , Ctrl +, , Í, , To the first box containing data, of the current row., , Ctrl +, , Ï, , To the first box containing data, of the current column., , Ctrl +, , Ð, , To the last box containing data, of the current column., , Ctrl + Page Up, , To the sheet in the left of the, current sheet., , user can scroll the sheet by rolling mouse wheel, which, is equivalent to clicking the up-arrow or down-arrow, buttons in the scroll bar., , Ctrl + Page Down, , To the sheet in the right of the, current sheet., , Ctrl + Home, , To the beginning of the sheet., , Moving with Scroll Bars, , Ctrl + End, , To the end of the sheet., , As shown in the above screen capture, there are two, scroll bars: one for moving vertically within the sheet,, and one for moving horizontally. Using the vertical scroll, bar, user may ?, •, , Move upward by one line by clicking the upwardpointing scroll arrow., , •, , Move downward by one line by clicking the downwardpointing scroll arrow., , •, , Move one next page, using next page button, (footnote)., , •, , Move one previous page, using previous page button, (footnote)., , •, , Use Browse Object button to move through the sheet,, going from one chosen object to the next., , Moving with Go To Command, Press F5 key to use Go To command as shown in fig-9,, which will display a dialogue box contains various options, to reach to a particular box., Normally, we use row and column number, for example, K5 and finally press Go To button., , Fig 9, , Moving with Keyboard, , Keystroke, , Where the Insertion Point Moves, , Î, , Forward one box, , Í, , Back one box, , Ï, , Up one box, , Ð, , Down one box, , PageUp, , To the previous screen, , Copa 1203909, , The following keyboard commands, used for moving, around your sheet, also move the insertion point -, , PageDown To the next screen, Home, , To the beginning of the current screen, , End, , To the end of the current screen, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished, , 129
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Conditional Formatting, , •, , MS Excel 2010 Conditional Formatting feature enables, to format a range of values so that the values outside, certain limits, are automatically formatted., Choose Home Tab " Style group " Conditional Formatting, dropdown., Various Conditional Formatting Options, •, , Top/Bottom Rules: It opens a continuation menu, with various options for defining the formatting rules, that highlight the top and bottom values, percentages,, and above and below average values in the cell, selection., , Suppose want to highlight the top 10% rows user can do, this with these Top/Bottom rules as shown in fig-12., , Fig 12, , Highlight Cells Rules ? It opens a continuation menu, with various options for defining the formatting rules, that highlight the cells in the cell selection that contain, certain values, text, or dates, or that have values, greater or less than a particular value, or that fall, within a certain ranges of values., , Copa 12039012, , Suppose to find cell with Amount 0 and Mark them as, red. Choose Range of cell " Home Tab " Conditional, Formatting DropDown " Highlight Cell Rules " Equal To as, on fig-10., , Fig 10, , Copa 12039010, , •, , Data Bars(fig-13): It opens a palette with different, color data bars that can apply to the cell selection to, indicate their values relative to each other by clicking, the data bar thumbnail., , With this conditional Formatting data Bars will appear in, each cell., , Fig 13, , After Clicking ok, the cells with value zero are marked as, red as shown in fig-11., , Copa 12039013, , Fig 11, , •, , Color Scales (Fig-14): It opens a palette with different, three- and two-colored scales that can apply to the, cell selection to indicate their values relative to each, other by clicking the color scale thumbnail., , Copa 12039011, , See the below screenshot with Color Scales, conditional, formatting applied., , 130, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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Linking Excel Worksheet Data Overview, , Fig 14, , In Excel, a link is a formula that dynamically pulls in, data from a cell in another worksheet. The worksheet, can be in the same workbook or a different workbook., , Copa 12039014, , The destination worksheet is the worksheet that contains, the link formula. The worksheet containing the data that, will be brought in is called the source worksheet., , • Icon Sets (Fig-15)? It opens a palette with different, sets of icons that can apply to the cell selection to indicate, their values relative to each other by clicking the icon, set., See the below screenshot with Icon Sets conditional, formatting applied., , Fig 15, , Any time the cell value in the source worksheet changes,, the cell containing the link formula will be updated as, well the next time the spreadsheet containing the link, formula is opened. This is just one of many reasons the, Excel software program is so powerful., Need for Linking Spreadsheet Data, The ability to create links often eliminates the need to, have identical data entered and updated in multiple, sheets. This saves time, reduces errors, and improves, data integrity. For example, a company's prices can be, stored in a 'Master Price List' worksheet, and others, needing pricing data can link to that worksheet., Consider a Sales Manager who has a detailed, spreadsheet for each salesperson, but would like a, summary sheet to compare salespersons' performance, and create grand totals. The summary sheet (destination), would bring in data from all the salespersons' sheets, (source)., Create the Worksheet Link, Before creating the link, format the cell, containing the link formula in the destination, worksheet to equal the format of the source data., For example, if the data from the source spreadsheet is, currency with 2 decimal points, then first format the target, cell for currency with 2 decimal places., , • New Rule: It opens the New Formatting Rule dialog, box, where define a custom conditional formatting rule, to apply to the cell selection., • Clear Rules: It opens a continuation menu, where, can remove the conditional formatting rules for the cell, selection by clicking the Selected Cells option, for the, entire worksheet by clicking the Entire Sheet option, or, for just the current data table by clicking the This Table, option., • Manage Rules: It opens the Conditional Formatting, Rules Manager dialog box, edit and delete particular rules, as well as adjust their rule precedence by moving them, up or down in the Rules list box., Link Excel Spreadsheet Data, Microsoft Excel provides the ability for cells in one, worksheet to be linked to cells in one or more other, worksheets. This is a great productivity tool and can, reduce the need for additional worksheets!, , METHOD ONE, 1. In the source worksheet, select the cell need to link, to and click the Copy button on the Home tab. Or, press Ctrl+C, or right-click and select Copy., 2. Switch to the destination spreadsheet and click the, cell want to link. Then, depending on the version of, Excel:, •, , Excel 2007, 2010, and 2013: On the Home tab, click, the down arrow below Paste and click Paste Link. In, newer versions also right-click and select the Paste, Link from the Paste menu., , •, , Excel 2003 and older versions: On the Edit menu,, click Paste Special, and then click Paste Link., , 3. Return to the source worksheet and press ESC to, remove the animated border around the cell., METHOD TWO, This is a fast method that works in a different order than, Method One., , 1. In the destination worksheet cell that will contain the, link formula, enter an equal sign (=)., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, 131, , Copyright @ NIMI Not to be Republished
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2. In the source worksheet, click in the cell that contains, the data and press the Enter key., , Fig 16, , Link Formula Example(Fig-16), In the example below, using Method One, we click in cell, B6 in the source worksheet and click Copy. Then, on the, destination worksheet, we click in cell B3, and paste the, link. The value ($3,500) automatically displays., , Copa 12039016, , Follow the same steps to link the data from the Denver, and Seattle worksheets to the Store Totals worksheet., And first formatted the cells to display the data as Currency., (Fig 16), , 132, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.39-1.7.41, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.7.42 - 1.7.46, COPA - Spread Sheet Application, Functions and formulas in MS-Excel 2010, Objectives : At the end of this lesson you shall be able to, • features & Functions of Microsoft Excel, • formulas and Functions, • move Around in Excel 2010, • conditional Formatting, • link Excel Spreadsheet Data, Formulas in MS Excel, formula, worksheet will be just simple tabular, representation of data. A formula consists of special code,, which is entered into a cell. It performs some calculations, and returns a result, which is displayed in the cell., Formulas use a variety of operators and worksheet, functions to work with values and text. The values and, text used in formulas can be located in other cells, which, makes changing data easy and gives worksheets their, dynamic nature. For example, it can quickly change the, data in a worksheet and formulas works., Elements of Formulas, A formula can consist of any of these elements ?, •, , Creating Formula, For creating a formula need to type in the Formula Bar., Formula begins with '=' sign. When building formulas, manually, and can either type in the cell addresses or, can point to them in the worksheet. Using the Pointing, method to supply the cell addresses for formulas is often, easier and more powerful method of formula building., When using built-in functions, to click the cell or drag, through the cell range that want to use when defining, the function's arguments in the Function Arguments, dialog box as shown in Fig 1., Fig Fig, 17 1, , Mathematical operators, such as +(for addition), and *(for multiplication), , Example •, , Copa 12039017, , =A1+A2 Adds the values in cells A1 and A2., Values or text, , Example =200*0.5 Multiplies 200 times 0.5. This formula uses only, values, and it always returns the same result as 100., •, , Cell references (including named cells and, ranges), , Example =A1=C12 Compares cell A1 with cell C12. If the cells, are identical, the formula returns TRUE; otherwise, it, returns FALSE., •, , Worksheet functions (such as SUMor AVERAGE), , Example =SUM(A1:A12) Adds the values in the range A1:A12., , As soon as complete a formula entry, Excel calculates, the result, which is then displayed inside the cell within, the worksheet (the contents of the formula, however,, continue to be visible on the Formula bar anytime the, cell is active). If you make an error in the formula that, prevents Excel from being able to calculate the formula, at all, Excel displays an Alert dialog box suggesting how, to fix the problem., Functions in Formula, Many formulas are create use available worksheet, functions. These functions enable to greatly enhance the, power of the formulas and perform calculations that are, difficult if use only the operators. For example, and can, use the LOG or SIN function to calculate the Logarithm, or Sin ratio. And cannot do this complicated calculation, by using the mathematical operators alone., , Copyright @ NIMI Not to be Republished, , 133
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Using Functions, , Function Arguments, , When type = sign and then type any alphabet the, searched functions will showfig 2., , In the above examples, notice that all the functions used, parentheses. The information inside the parentheses is, the list of arguments., , Fig 2, Fig 18, , Copa 12039018, , Functions vary in how they use arguments. Depending, on what it has to do, a function may use., , Suppose need to determine the largest value in a range., A formula can't tell the answer without using a function., We will use formula that uses the MAX function to return, the largest value in the range B3:B8 as, =MAX(A1:D100)as shown in fig 3., , FigFig, 193, , •, , No arguments - Examples ? Now(), Date(), etc., , •, , One argument - UPPER(), LOWER(), etc., , •, , A fixed number of arguments - IF(), MAX(), MIN(),, AVERGAGE(), etc., , •, , Infinite number of arguments, , •, , Optional arguments, , Built In Functions, MS Excel has many built in functions, which we can use, in our formula. To see all the functions by category,, choose Formulas Tab " Insert Function as shown in fig-5., Then Insert function Dialog appears from which we can, choose the function., , Another example of functions. Suppose to find if the cell, of month is greater than 1900 then we can give Bonus to, Sales representative. The we can achieve it with writing, formula with IF functions as =IF(B9>1900,"Yes","No"), as shown in fig 4., , Copa 12039021, , Copa 12039019, , Fig 5, Fig 21, , Functions by Categories, Let us see some of the built in functions in MS Excel., Text Functions, LOWER: Converts all characters in a supplied text string, to lower case, , FigFig, 204, , UPPER : Converts all characters in a supplied text string, to upper case, TRIM : Removes duplicate spaces, and spaces at the, start and end of a text string, CONCATENATE : Joins together two or more text, strings., , Copa 12039020, , Fig 4, , 134, , LEFT : Returns a specified number of characters from, the start of a supplied text string., MID : Returns a specified number of characters from, the middle of a supplied text string, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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RIGHT : Returns a specified number of characters from, the end of a supplied text string., LEN: Returns the length of a supplied text string, FIND: Returns the position of a supplied character or text, string from within a supplied text string (case-sensitive)., Date & Time, DATE: Returns a date, from a user-supplied year, month, and day., TIME: Returns a time, from a user-supplied hour, minute, and second., DATEVALUE: Converts a text string showing a date, to, an integer that represents the date in Excel's date-time, code., , two supplied numbers., Filters in MS Excel, Filtering data in MS Excel refers to displaying only the, rows that meet certain conditions. (The other rows gets, hidden.), Using the store data, if user interested in seeing data, where Shoe Size is 36, then set filter to do this. Follow, the below mentioned steps to do this., •, , Place a cursor on the Header Row., , •, , Choose Data Tab ¾ Filter to set filter as shown in, fig 6., , Fig 22Fig 6, , TIMEVALUE: Converts a text string showing a time, to, a decimal that represents the time in Excel., NOW: Returns the current date & time., TODAY: Returns today's date., Statistical, , Copa 12039022, , MAX: Returns the largest value from a list of supplied, numbers., MIN: Returns the smallest value from a list of supplied, numbers., AVERAGE: Returns the Average of a list of supplied, numbers., COUNT: Returns the number of numerical values in a, supplied set of cells or values., COUNTIF: Returns the number of cells (of a supplied, range), that satisfies a given criteria., SUM: Returns the sum of a supplied list of numbers, , •, , Click the drop-down arrow in the Area Row Header and, remove the check mark from Select All, which unselects, everything., , •, , Then select the check mark for Size 36 which will filter, the data and displays data of Shoe Size 36 as shown, in fig-23., , •, , Some of the row numbers are missing; these rows, contain the filtered (hidden) data., , •, , There is drop-down arrow in the Area column now shows, a different graphic - an icon that indicates the column, is filtered. (Fig 7), , Logical, AND: Tests a number of user-defined conditions and, returns TRUE if ALL of the conditions evaluate to TRUE,, or FALSE otherwise, OR: Tests a number of user-defined conditions and, returns TRUE if ANY of the conditions evaluate to TRUE,, or FALSE otherwise., NOT: Returns a logical value that is the opposite of a, user supplied logical value or expression i.e. returns, FALSE if the supplied argument is TRUE and returns, TRUE if the supplied argument is FAL, , Fig 7, Fig 23, , Math & Trig, , SIGN: Returns the sign (+1, -1 or 0) of a supplied number., SQRT: Returns the positive square root of a given, number., MOD: Returns the remainder from a division between, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , Copa 12039023, , ABS: Returns the absolute value (i.e. the modulus) of a, supplied number., , 135
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Using Multiple Filters(fig-24), , 10, FigFig26, , Filtering of records by multiple conditions i.e. by multiple, column values. Suppose after size 36 is filtered,need to, have the filter where color is equal to Coffee. After setting, filter for Shoe Size, choose Color column and then set, filter for color. (Fig 8), , Copa 12039026, , Copa 12039024, , Fig 8, Fig 24, , -, , Values - alphabetically or numerically., , -, , Cell Color - Based on Color of Cell., , Sorting in MS Excel, , -, , Font Color - Based on Font color., , Sorting data in MS Excel rearranges the rows based on, the contents of a particular column. sort a table to put, names in alphabetical order Or sort data by Amount from, smallest to largest or largest to smallest., , -, , Cell Icon - Based on Cell Icon., , •, , Clicking Ok will sort the data as on fig 11., , To Sort the data follow the steps mentioned below., •, , Fig Fig, 27 11, , Select the Column to sort data as on fig 9., , Choose Data Tab " Sort Below dialog appears., , •, , If the user sort data based on a selected column,, Choose Continue with the selection or if the data, sorting based on other columns, choose Expand, Selection., , •, , Sort the data based on the below Conditions as on, fig 10., , Sorting option is also available from the Home Tab. Choose, Home Tab " Sort & Filter. You can see the same dialog to, sort records as on fig 12., , Fig 28, , Fig 12, , Copa 12039028, , •, , Copa 12039027, , 12039025, , 9, FigFig25, , 136, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished
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Ranges in MS Excel:, A cell is a single element in a worksheet that can hold a, value, some text, or a formula. A cell is identified by its, address, which consists of its column letter and row, number. For example, cell B1 is the cell in the second, column and the first row., , to return the navigation keys to normal movement., •, , Type the cell or range address into the Name box and, press Enter. Excel selects the cell or range that, specified. (Fig 13), , Fig 13, Fig 29, , A group of cells is called a range. You designate a range, address by specifying its upper-left cell address and its, lower-right cell address, separated by a colon., •, , C24, , - A range that consists of a single cell., , •, , A1:B1, , - Two cells that occupy one row and two, columns., , •, , A1:A100 - 100 cells in column A., , •, , A1:D4, , Copa 12039029, , Example of Ranges:, , - 16 cells (four rows by four columns)., , Selecting Ranges (Fig-29), Selecting a range in several ways ?, , Selecting Complete Rows and Columns (Fig-30), , •, , Press the left mouse button and drag, highlighting, the range. Then release the mouse button. If drag to, the end of the screen, the worksheet will scroll., , When user need to select an entire row or column.and, can select entire rows and columns in much the same, manner as select ranges:, , •, , Press the Shift key while uses the navigation keys to, select a range., , •, , Click the row or column border to select a single row, or column., , •, , Press F8 and then move the cell pointer with the, navigation keys to highlight the range. Press F8 again, , •, , To select multiple adjacent rows or columns, click a, row or column border and drag to highlight additional, rows or columns., , •, , To select multiple (nonadjacent) rows or columns,, press Ctrl while click the row or column borders., (Fig 14), , Copa 12039030, , Fig, Fig14, 30, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.42 - 1.7.46, , Copyright @ NIMI Not to be Republished, , 137
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IT & ITES, Related Theory for Exercise 1.7.47 & 1.7.48, COPA - Spread Sheet Application, Data validations and Table management in MsExcel 2010, Objectives : At the end of this lesson you shall be able to, • data Validation, • data Table with Example, • charts and its types, • pivot table and pivot chart, • page setup and printing worksheet, • excel shortcut keys, Data Validation, , •, , MS Excel data validation feature allows to set up certain, rules that dictate what can be entered into a cell. For, example, user want to limit data entry in a particular cell, to whole numbers between 0 and 10. If the user makes, an invalid entry, and display a custom message as shown, fig 1., , Decimal - The user must enter a number. For example,, you can specify that the entry must be greater than or, equal to 10 and less than or equal to 20., , •, , List - The user must choose from a list of entries you, provide. You will create drop-down list with this, validation. You have to give input ranges then those, values will appear in the drop-down., , •, , Date - The user must enter a date. You specify a valid, date range from choices in the Data drop-down list., For example, you can specify that the entered data, must be greater than or equal to January 1, 2013, and, less than or equal to December 31, 2013., , •, , Time - The user must enter a time. Specify a valid, time range from choices in the Data drop-down list., For example, user can specify that the entered data, must be later than 12:00 p.m., , •, , Text Length - The length of the data (number of, characters) is limited. specify a valid length by using, the Data drop-down list. For example, that the length, of the entered data be 1 (a single alphanumeric, character)., , •, , Custom - To use this option, must supply a logical, formula that determines the validity of the user's entry, (a logical formula returns either TRUE or FALSE)., , Copa 12039031, , FigFig311, , Validation Criteria, To specify the type of data allowable in a cell or range,, follow the steps below, which shows all the three tabs of, the Data Validation dialog box., •, , Select the cell or range., , •, , Choose Data " Data Tools " Data Validation. Excel, displays its Data Validation dialog box having 3 tabs, settings, Input Message and Error alert., , Input Message Tab(fig 2), Fig 2, , Fig 32, , Here user can set the type of validation. Choose an option, from the Allow drop-down list. The contents of the Data, Validation dialog box will change, displaying controls, based on your choice., •, , Any Value - Selecting this option removes any existing, data validation., , Whole Number - The user must enter a whole, number.For example, you can specify that the entry, must be a whole number greater than or equal to 50., 138, •, , Copyright @ NIMI Not to be Republished, , Copa 12039032, , Settings Tab
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User can set the input help message with this tab. Fill the, title and Input message of the Input message tab and the, input message will appear when the cell is selected., , Fig 5, Fig 34, , Error Alert Tab(fig 3), , User specify an error message with this tab. Fill the title, and error message. Select the style of the error as stop,, warning or Information as per user need., , Copa 12039034, , Copa 12039032, , FigFig, 323, , Now, for creation of data table select the range of data, table. Choose Data Tab " What-If analysis dropdown ", Data table. It will display dialogue asking for Input row and, Input Column. Give the Input row as Price cell (In this, case cell B3) and Input column as quantity cell (In this, case cell B4) as shown in fig 6., Fig 6, Fig 35, , Data Table with Example (Fig 4), Fig 4, , Copa 12039033, , Copa 12039035, , Fig 33, , Fig 36, , Fig 7, , Copa 12039036, , Here user have the Price and quantity of many values., Also, have the discount for that as third variable for, calculating the Net Price. And can keep the Net Price, value in the organized table format with the help of the, data table. The Price runs horizontally to the right while, quantity runs vertically down. We are using a formula to, calculate the Net Price as Price multiplied by Quantity, minus total discount (Quantity * Discount for each, quantity) as shown in fig 5., , Clicking OK will generate data table as shown in fig 7. It, will generate the table formula. And change the price, horizontally or quantity vertically to see the change in, the Net Price., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 139
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Charts, A chart is a visual representation of numeric values., Charts (also known as graphs) have been an integral, part of spreadsheets. Charts generated by early, spreadsheet products were quite crude, but thy have, improved significantly over the years. Excel provides, you with the tools to create a wide variety of highly, customizable charts. Displaying data in a well-conceived, chart can make your numbers more understandable., Because a chart presents a picture, charts are particularly, useful for summarizing a series of numbers and their, interrelationships., , •, , Stock: This chart type is most often used for stock, price data, but can also be used for scientific data, (for example, to indicate temperature changes)., , •, , Surface: A surface chart is useful to find the optimum, combinations between two sets of data. As in a, topographic map, colors and patterns indicate areas, that are in the same range of values., , •, , Doughnut: Like a pie chart, a doughnut chart shows, the relationship of parts to a whole; however, it can, contain more than one data series., , •, , Bubble: Data that is arranged in columns on a, worksheet, so that x values are listed in the first, column and corresponding y values and bubble size, values are listed in adjacent columns, can be plotted, in a bubble chart., , •, , Radar: A radar chart compares the aggregate values, of a number of data series., , Types of Charts, There are various chart types available in MS Excel as, shown in fig 8., Fig 8, , Fig 37, , Creating Chart, , •, , Column: Column chart shows data changes over a, period of time or illustrates comparisons among items., , •, , Bar: A bar chart illustrates comparisons among, individual items., , •, , Pie: A pie chart shows the size of items that make up, a data series, proportional to the sum of the items. It, always shows only one data series and is useful to, emphasize a significant element in the data., , •, , Line: A line chart shows trends in data at equal, intervals., , •, , Area: An area chart emphasizes the magnitude of, change over time., , •, , X Y Scatter: An xy (scatter) chart shows the, relationships among the numeric values in several, data series, or plots two groups of numbers as one, series of xy coordinates., , •, , Select the data for which you want to create the chart., , •, , Choose Insert Tab " Select the chart or click on the, Chart groupto see various chart types., , •, , Select the chart of the choice and click OK to generate, the chart as shown in fig 9., Fig 9, Fig 38, , Copa 12039038, , Copa 12039037, , To create charts for the data by below mentioned steps., , Editing Chart, You can edit the chart at any time after you have created, it., •, , 140, , select the different data for chart input with Right click, on chart " Select data. Selecting new data will, generate the chart as per the new data, as shown in, fig 10., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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This will generate the Pivot table pane as shown in fig-41., various options available in the Pivot table pane. And can, select fields for the generated pivot table. (Fig 13), , Fig 10, Fig 39, , •, , change the X axis of the chart by giving different inputs, to X-axis of chart., , •, , change the Y axis of chart by giving different inputs to, Y-axis of chart., , Pivot Tables, A pivot table is essentially a dynamic summary report, generated from a database. The database can reside in, a worksheet (in the form of a table) or in an external, data file. A pivot table can help transform endless rows, and columns of numbers into a meaningful presentation, of the data. Pivot tables are very powerful tool for, summarized analysis of the data., Pivot tables are available under Insert tab " PivotTable, dropdown " PivotTable., Pivot Table Example (Fig-40), Now, let us see Pivot table with the help of example., Suppose huge data of voters and need to see the, summarized data of voter Information per party, use the, Pivot table for it. Choose Insert tab " Pivot Table to insert, pivot table. MS Excel selects the data of the table. and, select the pivot table location as existing sheet or new, sheet. (Fig 11), , Copa 12039041, , Copa 12039039, , FigFig, 4112, , •, , Column labels: A field that has a column orientation, in the pivot table. Each item in the field occupies a, column., , •, , Report Filter: User can set the filter for the report as, year, and then data gets filtered as per the year., , •, , Row labels: A field that has a row orientation in the, pivot table. Each item in the field occupies a row., , •, , Values area: The cells in a pivot table that contain, the summary data. Excel offers several ways to, summarize the data (sum, average, count, and so, on)., , After giving input fields to the pivot table, it generates the, pivot table with the data as shown in fig 13., FigFig, 4213, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , Copa 12039042, , Copa 12039040, , Fig 40Fig 11, , 141
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Pivot Charts, , •, , A pivot chart is a graphical representation of a data, summary, displayed in a pivot table. A pivot chart is, always based on a pivot table. Although Excel lets to, create a pivot table and a pivot chart at the same time,, user can't create a pivot chart without a pivot table. All, Excel charting features are available in a pivot chart., , Press Ctrl+P and then click the Print button (or press, Enter)., , FigFig, 4516, , Pivot charts are available under Insert tab ¾ PivotTable, dropdown ¾ PivotChart., Pivot Chart Example, , Copa 12039045, , Suppose huge data of voters and need to see the, summarized view of the data of voter, Information per party in the form of charts, then use the, Pivot chart for it. Choose Insert tab ¾ Pivot Chart to, insert the pivot table. (Fig 14), , FigFig, 4314, Adjusting Common Page Setup Settings, , Copa 12039043, , User can adjust the print settings available in the Page, setup dialogue in different ways as discussed below. Page, setup options include Page orientation, Page Size, Page, Margins, etc., , MS Excel selects the data of the table. And select the, pivot chart location as an existing sheet or a new sheet., Pivot chart depends on automatically created pivot table, by the MS Excel. generate the pivot chart in the below, fig 15., , •, , The Print screen in Backstage View, displayed when, choose File " Print., , •, , The Page Layout tab of the Ribbon., , Choosing Your Printer(fig-46), To switch to a different printer, choose File ¾ Print and, use the drop-down control in the Printer section to select, any other installed printer. (Fig 17), Fig 17, , Fig 46, , Quick Print, If user want to print a copy of a worksheet with no layout, adjustment, use the Quick Print option. There are two, ways in which we can use this option., •, , Copa 12039046, , Copa 12039044, , Fig Fig, 4415, , Specifying What You Want to Print(Fig 18), Sometimes print only a part of the worksheet rather than, the entire active area. Choose File ¾ Print and use the, controls in the Settings section to specify what to print., •, , Active Sheets: Prints the active sheet or sheets that, you selected., , Choose File " Print (which displays the Print pane),, and then click the Print button as shown in fig 16., , 142, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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•, , Entire Workbook: Prints the entire workbook, including, chart sheets., , •, , Selection: Prints only the range that selected before, choosing File ¾ Print., , MS Excel Keyboard Short-cuts, MS Excel offers many keyboard short-cuts. Below is the list of all the major shortcut keys in Microsoft Excel., (Fig 18), , Copa 12039047, , FigFig, 4718, , •, , Ctrl + A, , -, , Selects all contents of the worksheet., , •, , Ctrl + B, , -, , Bold highlighted selection., , •, , Ctrl + I, , -, , Italicizes the highlighted selection., , •, , Ctrl + K, , -, , Inserts link., , •, , Ctrl + U, , -, , Underlines the highlighted selection., , •, , Ctrl + 1, , -, , Changes the format of selected cells., , •, , Ctrl + 5, , -, , Strikethrough the highlighted selection., , •, , Ctrl + P, , -, , Brings up the print dialog box to begin printing., , •, , Ctrl + Z, , -, , Undo last action., , •, , Ctrl + F3, , -, , Opens Excel Name Manager., , •, , Ctrl + F9, , -, , Minimizes the current window., , •, , Ctrl + F10, , -, , Maximize currently selected window., , •, , Ctrl + F6, , -, , Switches between open workbooks or windows., , •, , Ctrl + Page up, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Page down, , -, , Moves between Excel work sheets in the same Excel document., , •, , Ctrl + Tab, , -, , Moves between Two or more open Excel files., , •, , Alt + =, , -, , Creates a formula to sum all of the above cells, , •, , Ctrl + ', , -, , Inserts the value of the above cell into cell currently selected., , •, , Ctrl + Shift + !, , -, , Formats the number in comma format., , •, , Ctrl + Shift + $, , -, , Formats the number in currency format., , •, , Ctrl + Shift + #, , -, , Formats the number in date format., , •, , Ctrl + Shift + %, , -, , Formats the number in percentage format., , •, , Ctrl + Shift + ^, , -, , Formats the number in scientific format., , •, , Ctrl + Shift + @, , -, , Formats the number in time format., , •, , Ctrl + Arrow key, , -, , Moves to the next section of text., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished, , 143
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•, , Ctrl + Space, , -, , Selects the entire column., , •, , Shift + Space, , -, , Selects the entire row., , •, , Ctrl + -, , -, , Deletes the selected column or row., , •, , Ctrl + Shift + =, , -, , Inserts a new column or row., , •, , Ctrl + Home, , -, , Moves to cell A1., , •, , Ctrl + ~, , -, , Switches between showing Excel formulas or their values in cells., , •, , F2, , -, , Edits the selected cell., , •, , F3, , -, , After a name has been created F3 will paste names., , •, , F4, , -, , Repeat last action. For example, if you changed the color of text in another, cell pressing F4 will change the text in cell to the same color., , •, , F5, , -, , Goes to a specific cell. For example, C6., , •, , F7, , -, , Spell checks the selected text or document., , •, , F11, , -, , Creates chart from the selected data., , •, , Ctrl + Shift + ;, , -, , Enters the current time., , •, , Ctrl + ;, , -, , Enters the current date., , •, , Alt + Shift + F1, , -, , Inserts New Worksheet., , •, , Alt + Enter, , -, , While typing text in a cell pressing Alt + Enter will move to the next line, allowing for multiple lines of text in one cell., , •, , Shift + F3, , -, , Opens the Excel formula window., , •, , Shift + F5, , -, , Brings up the search box., , 144, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.7.47 &1.7.48, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.8.49 - 1.8.57, COPA - Image Editing and Presentations, Image editing, presentations, Objectives : At the end of this lesson you shall be able to, • Introduction to Power Point and its advantages, • Creation of slide shows, • Fine tuning of presentations, Introduction, , Working with PowerPoint 2010, , PowerPoint is a presentation graphics software program, that is part of the Microsoft Office package. It uses a, graphical approach for the presentations in the form of, slide shows that accompany the oral delivery of the topic., This program is widely used in business and classrooms, and is an effective tool when used for training purposes., , Step 1: Click the Start button., , PowerPoint 2010 allowsto create presentations for printing or online viewing using a variety of tools. These include wizards to help with the content and look and feel, of the presentations to animation tools to create moving, images., , Copa 1214901, , PowerPoint is one of the simplest computer programs, to learn. It is the easiest program used worldwide for, presentations that creates professional looking presentations. It is easy to customize presentations with company logo and has design templates that come with the, programs. In addition to an on screen slide show,, PowerPoint has printing options that allow the presenter, to provide handouts and outlines for the audience as, well as notes pages for the speaker to refer to during the, presentation., , Fig 1, , Step 2: Click All Programs option from the menu., , Fig 2, , Presentation, , Copa 1214902, , A presentation is a collection of data and information, that is to be delivered to a specific audience. A, PowerPoint presentation is a collection of electronic, slides that can have text, pictures, graphics, tables, sound, and video. This collection can run automatically or can, be controlled by a presenter., Advantage and application of PowerPoint 2010, Professional looking presentations, , •, , Animated presentations shown on a monitor or overhead screen, , •, , Notes for the speaker, , •, , Handouts for the audience, , •, , Paper printouts of your slide, , •, , Overhead projector transparencies, , •, , Movies, , Step 3: Search for Microsoft Office from the sub menu, and click it., Fig 3, , Copa 1214903, , •, , Copyright @ NIMI Not to be Republished, , 145
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Step 4: Search for Microsoft PowerPoint 2010 from the, submenu and click it., , Fig 4, , File Tab, This tab opens the Backstage view which basically allows to manage the file and settings in PowerPoint. This, can save presentations, open existing ones and create, new presentations based on blank or predefined templates. The other file related operations can also be executed from this view., Ribbon, , This will launch the Microsoft PowerPoint 2010 application and the following is the presentation window., , Copa 1214905, , Fig 5, , Copa 1214907, , Copa 1214904, , Fig 7, , The ribbon contains three components:, •, , Tabs: They appear across the top of the Ribbon and, contain groups of related commands. Home, Insert,, Page Layout are examples of ribbon tabs., , •, , Groups: They organize related commands; each, group name appears below the group on the Ribbon., For example, a group of commands related to fonts, or a group of commands related to alignment, etc., , •, , Commands: Commands appear within each group, as mentioned above., , Title Bar, This is the top section of the window. It shows the name, of the file followed by the name of the program which in, this case is Microsoft PowerPoint., Slide Area, This is the area where the actual slide is created and, edited.Add, edit and delete text, images, shapes and, multimedia is supported in this section., , PowerPoint Screen, Fig 6, , Help, The Help Icon can be used to get PowerPoint related, help anytime. Clicking on the "?" opens the PowerPoint, Help window where there is a list of common topics to, browse from. Specific topics from the search bar at the, top can also be used for searching., Zoom Options, The zoom control zooms in for a closer look at the text., The zoom control consists of a slider that can slide left, or right to zoom in or out, - and + buttons to can be used, to increase or decrease the zoom factor. The maximum, zoom supported by PowerPoint is 400% and the 100%, is indicated by the mark in the middle., , Copa 1214906, , Slide Views, The group of four buttons located to the left of the Zoom, control, near the bottom of the screen, lets to switch, between PowerPoint views., •, , 146, , Normal Layout view: 1 This displays page in normal, view with the slide on the right and a list of thumbnails to the left. This view allowsuser to edit individual, slides and also rearrange them., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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•, , Slide Sorter view: This displays all the slides as a, matrix. This view only allows the user to rearrange, the slides but not edit the contents of each slide., , •, , Reading View: This view is like a slideshow with access to the Windows task bar in case the user need, to switch windows. However, like the slideshow user, cannot edit anything in this view., , •, , First Pane ? This is the commands pane which consists of all the commands that would typically found, in the file menu of older versions. it also has the, Options menu which edits the options on the program, like customizing the ribbon., , Various commands under the first pane are described in, the table below ?, S.No, , Notes Section, , 1, , This sections allows user to add notes for the presentation. These notes will not be displayed on the screen, during the presentation; these are just quick reference, for the presenter., , Command & Description, Save, This allows user to save a new file or an existing, file in standard format. If user is working on a pre, viously saved file this will save the new changes, in the same file format. If user is working on a, new file, this command would be similar to the, Save As command., , Quick Access Toolbar, The Quick Access Toolbar is located just under the ribbon. This toolbar offers a convenient place to group the, most commonly used commands in PowerPoint. User, can customize this toolbar to suit their needs., , 2, , Save As, Allows user to specify the file name and the file, type before saving the file., , Slide Tab, 3, , This section is available only in the Normal view. It displays all the slides in sequence. User can add, delete, and reorder slides from this section., , Open, Allows user to open new PowerPoint files., , 4, , Backstage View in Powerpoint 2010, , Close, Allows user to close an existing file., , In Office 2010, Microsoft replaced the traditional file, menu with the new Backstage view. This view not only, offers all the menu items under the file menu, but additional details which makes management of files a lot, easier., , 5, , Info, Displays the information about the current file., , 6, , Recent, Lists series of recently viewed or edited, PowerPoint files., , Accessing Backstage View, User can access the Backstage view simply by clicking, on the File tab. They can exit this view by clicking on, any tab (including the File tab again). 'Esc' button on, the keyboardcanalso be pressed for the same., , 7, , New, Allows user to create a new file using blank or, pre-defined templates., , Organization of Backstage View, , 8, , The backstage view has three sections or panes., , Print, Allows user to select the printer settings and print, the presentation., , Fig 8, , 9, , Save & Send, Allows user to share your presentation with larger, audience via emails, web, cloud services, etc., , 10, , Help, Provides access to PowerPoint Help., , 11, , Options, Allows user to set various options related to, PowerPoint program., , Copa 12149008, , 12, , Exit, Closes the presentation and exits the program., , •, , Second Pane ? This is the subcommands pane. This, will list all the commands related to the main command chosen in the first pane. For example, if user, selects Print in the first pane, user get to choose the, printer and adjust the print settings in the second pane., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 147
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•, , Third Pane ? This is the preview or file information page., Depending on the command and the subcommand user, select, this pane will either display the properties of, the file or give a preview of the file., , Creating Presentation using Powerpoint 2010, PowerPoint offers a host of tools that will aid the user in creating a presentation. These tools are organized logically, into various ribbons in PowerPoint. The table below describes the various commands that can be accessed from the, different menus., Menu Category, , Ribbon Commands, , Home, , Clipboard functions, manipulating slides, fonts, paragraph settings, drawing objects and, editing functions., , Insert, , Insert tables, pictures, images, shapes, charts, special texts, multimedia and symbols., , Design, , Slide setup, slide orientation, presentation themes and background., , Transitions, , Commands related to slide transitions., , Animations, , Commands related to animation within the individual slides., , Slide Show, , Commands related to slideshow set up and previews., , Review, , Proofing content, language selection, comments and comparing presentations., , View, , Commands related to presentation views, Master slides, color settings and window arrange, ments., , Besides these depending on the objects selected in the, slide, there are other menu tabs that get enabled., Add New Slides in Powerpoint 2010, The following are the steps that allows the user to insert, a new slide ., , Step 2: The new slide is inserted. The layout of this slide, can be changed to suit the design requirements., , Fig 10, , Step 1: Right-click in the Navigation Pane under any, existing slide and click on the New Slide option., , Copa 1214909, , Copa 12149010, , Fig 9, , 148, , Step 3: To change the slide layout, right-click on the, newly inserted slide and go to the Layout option where, user can choose from the existing layout styles available ., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Subtitle Box, , Fig 11, , This is found only in slides with the Title layout. This is, indicated by "Click to add subtitle", , Copa 12149011, , Copa 12149013, , Fig 13, , Same steps can be followed to insert a new slide in between existing slides or at the end on the slide list., When we insert a new slide, it inherits the layout of its, previous slide with one exception. If inserting a new, slide after the first slide (Title slide), the subsequent slide, will have the Title and Content layout., , Fig 12, , Content Box, This is found in most of the slides that have a placeholder for adding content. This is indicated by "Click to, add text". This box allows user to add text as well as, non-text content. To add text to such a box, click anywhere on the box, except on one of the content icons in, the center and start typing., , Copa 12149014, , Copa 12149012, , Fig 14, , Adding Text in Boxes in Powerpoint 2010, PowerPoint allows users to add text to the slide in a, well-defined manner to ensure the content is well distributed and easy to read. The procedure to add the text, in a PowerPoint slide is always the same - just click in, the text box and start typing. The text will follow the default formatting set for the text box, although this formatting can be changed later as required., The most common content blocks in PowerPoint are:, , Text Only Box, This is not a default content box available in PowerPoint,, but user can create it using Slide Master, if required., This is also indicated by "Click to add text". The only, difference between the Text Only Box and the Content, Box is that the former only supports text in the content, area., , Title Box, This is typically found on slides with the title layout and, in all the slides that have a title box in them. This box is, indicated by "Click to add title"., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 149
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Fig 18, , Copa 12149016, , Fig 16, , Adding New Text Boxes in Powerpoint 2010, , Copa 12149018, , Most of the standard layouts come with the text box option. As mentioned, text boxes will have "Click to add, text" as the default text. Here are the steps to add new, text boxes in slide., Step 1: Click on the Text Box icon in the Home ribbon, under the Drawingsection., , Copa 12149016, , Fig 16, , Step 4: Alternately, user can click and drag the cursor, without releasing the click to create a text box., , Fig 19, , Step 2 : User will get the insert text box cursor that looks, like an inverted cross., , Copa 12149019, , Fig 17, , The size of the text box can be adjusted by selecting, one of the edges marked by squares or corners marked, by circles., , Copa 12149017, , Slide Show in Powerpoint 2010, , Fig 20, Copa 12149020, , Step 3: Click to insert a text box. User can now start, typing directly into the text box., , Most PowerPoint presentations are created to be run as, a slideshow. Most of these features of Powerpoint 2010, are really to help user create a good slideshow without, having to go through the entire presentation over and, over again after every minor change. Features related, to running the slideshow are grouped under the Slideshow, ribbon., , 150, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished
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Section, , Menu Item, , Description, , Start Slideshow, , From Beginning, , Starts slideshow from beginning, , From Current Slide, , Starts slideshow from the current slide, , Broadcast Slideshow, , Allows users to broadcast the slideshows, using Microsoft's PowerPoint Broadcast Service, , Custom Slideshow, , Builds a custom slideshow by picking the slides you, want to run, , Set Up Slideshow, , Helps set up the slideshow including browser/ full screen, display, show options with or without narration/ animation,, pen and laser color during the slideshow and the slides to, be presented during the show, , Hide Slide, , Helps mark/ unmark the slide as hidden, so it is skipped or, shown during the slideshow respectively, , Rehearse Timing, , Allows users to rehearse the timing on each slide and the, entire slideshow, , Record Slideshow, , Records the slideshow including narration and animation, , Slideshow Checkboxes, , Helps set or avoid the use of narrative audio and rehearsed, timings during the show. Display media controls in the, slideshow view, , Resolution, , Defines resolution in slideshow view, , Show Presentation on, , Picks the monitor to display the presentation one - in case, of multiple monitors, , Use Presenter View, , Run presentation in Presenter view rather than just slideshow, view, , Set Up, , Monitors, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.08.49 - 1.08.57, , Copyright @ NIMI Not to be Republished, , 151
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IT & ITES, Related Theory for Exercise 1.9.58 - 1.9.61, COPA - Database Management Systems, Concepts of data and Databases, Objectives : At the end of this lesson you shall be able to, • explain database structure and control, • describe Ms access database utilities., Microsoft Access is a Database Management System, (DBMS) from Microsoft that combines the relational, Microsoft Jet Database Engine with a graphical user, interface and software-development tools. It is a member, of the Microsoft Office suite of applications, included in, the professional and higher editions., •, , Microsoft Access is just one part of Microsoft's overall, data management product strategy., , •, , It stores data in its own format based on the Access, Jet Database Engine., , •, , Like relational databases, Microsoft Access also, allows you to link related information easily. For, example, customer and order data. However, Access, 2013 also complements other database products, because it has several powerful connectivity features., , •, , It can also import or link directly to data stored in, other applications and databases., , •, , As its name implies, Access can work directly with, data from other sources, including many popular PC, database programs, with many SQL (Structured, Query Language) databases on the desktop, on, servers, on minicomputers, or on mainframes, and, with data stored on Internet or intranet web servers., , •, , Access can also understand and use a wide variety, of other data formats, including many other database, file structures., , •, , You can export data to and import data from word, processing files, spreadsheets, or database files, directly., , •, , Access can work with most popular databases that, support the Open Database Connectivity (ODBC), standard, including SQL Server, Oracle, and DB2., , •, , Software developers can use Microsoft Access to, develop application software., , •, , Report (optional): Information from the database is, organized in a nicepresentation that can be printed, in an Access Report., , Architecture, •, , Access calls anything that can have a name an object., Within an Access desktop database, the main objects, are tables, queries, forms, reports, macros, data, macros, and modules., , •, , If you have worked with other database systems on, desktop computers, you might have seen the term, database used to refer to only those files in which, you store data., , •, , But, in Access, a desktop database (.accdb) also, includes all the major objects related to the stored, data, including objects you define to automate the, use of your data., , RDBMS, In the computing system (web and business applications),, there are enormous data that comes out every day from, the web. A large section of these data is handled by, Relational database management systems (RDBMS)., The idea of relational model came with E.F.Codd's 1970, paper "A relational model of data for large shared data, banks" which made data modeling and application, programming much easier. Beyond the intended benefits,, the relational model is well-suited to client-server, programming and today it is predominant technology for, storing structured data in web and business applications., MS Access - RDBMS, Microsoft Access has the look and feel of other Microsoft, Office products as far as its layout and navigational, aspects are concerned, but MS Access is a database, and, more specifically, a relational database., •, , Microsoft Access stores information which is called a, database. To use MS Access, you will need to follow, these four steps:, , Before MS Access 2007, the file extension was *.mdb,, but in MS Access 2007 the extension has been, changed to *.accdb extension., , •, , Database Creation: Create your Microsoft Access, database and specify what kindof data you will be, storing., , Early versions of Access cannot read accdb, extensions but MS Access 2007 and later versions, can read and change earlier versions of Access., , •, , An Access desktop database (.accdb or .mdb) is a, fully functional RDBMS., , •, , It provides all the data definition, data manipulation,, and data control features that you need to manage, large volumes of data., , •, , •, , Data Input: After your database is created, the data, of every business day canbe entered into the Access, database., , •, , Query: This is a fancy term to basically describe the, process of retrievinginformation from the database., , 152, , Copyright @ NIMI Not to be Republished
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You can use an Access desktop database (.accdb or, .mdb) either as a standalone RDBMS on a single, workstation or in a shared client/server mode across a, network., , •, , A desktop database can also act as the data source, for data displayed on webpages on your company, intranet., , •, , When you build an application with an Access desktop, database, Access is the, , RDBMS., Data Definition, Let us now understand what Data Definition is:, •, , •, , •, , In document or a spreadsheet, you generally have, complete freedom to define the contents of the, document or each cell in the spreadsheet., In a document, you can include paragraphs of text, a, table, a chart, or multiple columns of data displayed, with multiple fonts., In spreadsheet, you can have text data at the top to, define a column header for printing or display, and, you might have various numeric formats within the, same column, depending on the function of the row., , •, , An RDBMS allows you to define the kind of data you, have and how the data should be stored., , •, , You can also usually define rules that the RDBMS, can use to ensure the integrity of your data., , •, , For example, a validation rule might ensure that the, user can't accidentally store alphabetic characters in, a field that should contain a number., , Data Manipulation, Working with data in RDBMS is very different from, working with data in a word processing or spreadsheet, program., •, , In a word processing document, you can include, tabular data and perform a limited set of functions on, the data in the document., , •, , You can also search for text strings in the original, document and, with ActiveX controls, include tables,, charts, or pictures from other applications., , •, , In a spreadsheet, some cells contain functions that, determine the result you want, and in other cells, you, enter the data that provides the source information, for the functions., , •, , An RDBMS provides you many ways to work with, your data. For example,, , •, , You can search a single table for information or, request a complex search across several related, tables., , •, , You can update a single field or many records with a, single command., , •, , You can write programs that use RDBMS commands, to fetch data that you want to display and allow the, user to update the data., , Access uses the powerful SQL database language to, process data in your tables. Using SQL, you can define, the set of information that you need to solve a particular, problem, including data from perhaps many tables., Data Control, Spreadsheets and word processing documents are great, for solving single-user problems, but they are difficult to, use when more than one person needs to share the data., •, , When you need to share your information with others,, RDBMS gives you the flexibility to allow multiple users, to read or update your data., , •, , An RDBMS that is designed to allow data sharing, also provides features to ensure that no two people, can change the same data at the same time., , •, , The best systems also allow you to group changes, (which is also known as transaction) so that either all, the changes or none of the changes appear in your, data., , •, , You might also want to be sure that no one else can, view any part of the order until you have entered all, of it., , •, , Because you can share your Access data with other, users, you might need to set some restrictions on, what various users are allowed to see or update., , Designing a Database, The first step in creating a database is to think about, why you need it-what is its purpose? Once you know the, answer, you can begin designing your own database., Ask yourself questions like What kinds of information, will it store? How will I have to break down this information, so it can be stored in my database? How will I use the, data once it's in there?, The bookstore scenario, The best way to learn about designing a database is to, jump right in to the process. Let's pretend we work for, the bookstore, and we need to build a database for the, store to use. Let's think about what we might need the, database to do for us., The following diagram shows that we have customers and, sell books via orders, both in the store and online., , Fig 1, , Copa 1225801, , •, , The store needs a way to keep track of these things., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 153
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Determine the purpose of the database, The first step of designing a database is to determine the, purpose of the database. What do we need it to do?, At Ready-2-Read, our customers will place orders for, books. At the very least, we will want our database to, track the books we sell, the customers we sell them to,, and the date of each of the orders., The database will also be able to tell us where our, customers live when we need to send them books or, coupons. Additionally, we can use it to track our sales or, to make a bestseller list to post in the store., Plan database tables, Once we've established its purpose, we can begin about, how to break up the information into the tables the, database will need to store data. Recall that a table is a, collection of records, and each record is broken up into, the smallest pieces of needed information, called fields., , Book the customer is ordering, and the Date the order is, placed., Creating a new database with Access, When you launch Access 2007/2010, you will see the, Getting Started window., In the left pane, the template categories-including the, featured local templates-are listed, as well as the, categories on Office Online. Templates are prebuilt, databases focused on a specific task that you can, download and use immediately., You will also see the New Blank Database option, which, allows you to build your own database from scratch., , Fig 2, , Customers, , -, , Orders, , -, , Books, , Plan table fields, Once you know what tables you need, the next step is, deciding what fields belong in each table. Remember, that fields are the smallest chunk of information in any, record., Let's look at our Ready-2-Read bookstore example again., There will be several fields in our Customers table. We'll, obviously want each customer's first name and last name., We'll also need an address if we need to send a customer, his order. Email will be necessary if we need to contact, the customer if there is an issue with the order., Customers, , Books, , Orders, , First Name, , Title, , Customer, , Last Name, , Author First, , Book, , Street, , Author Last, , Date, , City, , Price, , State, , Category, , When you choose the New Blank Database option at the, top of the window, you will be prompted to rename the, database from the default name, which is, Database1.accdb. Rename the database whatever you, want. In the example below, we named the database, Ready2Read because it's the name of the store in our, scenario., Fig 3, , Copa 1225803, , -, , Copa 1225802, , Because we're planning a database to track our, customers, the books we have, and the orders our, customers place, we will need a table for each one of, these., , Pin/Zip Code, Email, We will also need several fields in the Books table. Title, and Author make sense for books. We'll need a Price for, each book. Category will help usknow what type of books, sell the best so we can order more books that fit into this, category., The Orders table will have fewer fields. We'll need this, table to track the Customer who is placing the order, the, 154, , Click Create to finish naming the database., Setting up tables, The new database opens with one table showing as a, default. It also defaults to naming this table Table1 in both, the navigation pane and the Table tab itself. You will want, to name your tables based on your database design plan., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Copa 1225804, , Naming a table, To give the table a unique name, you must first click on, the Microsoft Office button in the upper-left corner of the, application., , Copa 1225807, , Fig 7, , Fig 4, , TIP: Give your tables logical, easy-to-understand names., To rename a table:, With the table closed, right-click the Table you want to, rename in the navigation pane. Select the Rename option, that appears in the menu., Fig 8, , Next, select Save from the menu. The Save As dialog box, will appear to let you save the table whatever name you, want., Fig 6, , Copa 1225808, , Copa 1225805, , Fig 5, , The table name will be highlighted and a cursor will appear,, which means you can now type the new name right there., Left-click anywhere outside of the table name to make the, change., To close a table:, , Copa 1225806, , There are several ways to close an active table. You can, right-click the Table tab and choose Close from the menu., Fig 9, , Copa 1225809, , The new table names appear in both the navigation pane, and the Table tab itself, as you can see in the picture, below., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 155
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A more common method is to click the X that appears in, the top-right corner of the active database object window., , Copa 12258010, , Fig 10, , To open a table:, To open a table, right-click the Table name of the table, you want to open in the navigation pane, then choose, Open from the menu., , Fig 11, , Next, select Table from the Tables command group. A, new table will open in the active database object window., You must name your table using the Save command, from Microsoft Office menu., Adding fields to a table, Access 2007 allows you to add fields to tables when you, are:, •, , Working in Datasheet view, which looks like a, spreadsheet, , •, , Working in Design view, where you are able to set more, controls for your fields, , Either way, you need to know how to switch between the, two views., To switch views:, Select the Views command group from either the Home, tab (seen below) or the Datasheet tab on the Ribbon. Select, the view option you want from the menu., , A more common method is to double-click the table name, in the navigation pane. The selected table will open in, the active database object window., Adding more tables to the database, By default, Access 2007 starts out with one table. To add, more tables to the database, click the Create tab on the, Ribbon., , Fig 12, , Copa 12258013, , Copa 12258011, , Fig 13, , Adding fields in Datasheet view, By default, Access 2007 creates one field in each new, table: the ID field. This field auto-numbers to give each, record in the table a unique number identifier. Recall, that records are the rows in a table. You may want to, rename the ID field with a unique name because the ID, field appears automatically in every table you create., While this is not necessary, it may help avoid confusion, when setting up table relationships., , 156, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258014, , Copa 12258012, , Fig 14
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To add more fields to a table in Datasheet view, doubleclick the Add New Field header., Fig 15, , To add a new field to a table in Design view, click in the, cell where you want the new field and type the field name., When you switch back to Datasheet view, your new field, appears as its own column, as seen below., , The Add New Field text will disappear from the header., Name the field by typing the name directly into the header., Press the Tab key on your keyboard to move to the next, field., Adding fields in Design view, In Design view, the field names are along the lefthand, column instead of across the top like in Datasheet view,, as seen below., , Copa 12258017, , Copa 12258015, , Fig 17, , Datatypes, Every field in a table has properties and these properties, define the field's characteristics and behavior. The most, important property for a field is its data type. A field's data, type determines what kind of data it can store. MS Access, supports different types of data, each with a specific, purpose., •, , The data type determines the kind of the values that, users can store in any given field., , •, , Each field can store data consisting of only a single, data type., , Copa 12258016, , Fig 16, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 157
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Here are some of the most common data types you will find used in a typical Microsoft Access database., Type of Data, , Description, , Size, , Text or combinations of text and numbers,, Short Text, , Up to 255, , including numbers that do not require, characters. calculating (e.g. phone numbers)., , Long Text, , Lengthy text or combinations of text and, , Up to 63, 999, , numbers. characters., Numeric data used in mathematical, Number, , 1, 2, 4, or 8 bytes, , (16 bytes if set to calculations., Replication ID)., , Date/Time, , Date and time values for the years 100 through, , 8 bytes., , 9999., Currency values and numeric data used in, Currency, , mathematical calculations involving data with, , 8 bytes., , one to four decimal places., A unique sequential (incremented by 1), , 4 bytes (16 bytes if, , number or random number assigned by, AutoNumber, , set to Replication Microsoft Access whenever, a new record is ID). added to a table., Yes and No values and fields that contain only, , Yes/No, , 158, , one of two values (Yes/No, True/False, or, , 1 bit., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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Here are some of the other more specialized data types, you can choose from in Access., Data Types, , Description, , Attachment, , Size, , Files, such as digital photos. Multiple files can be, attached per record. This data type is not available, , Up to about 2 GB., , in earlier versions of Access., OLE objects, , OLE objects can store pictures, audio, video, or, , Up to about 2 GB., , other BLOBs (Binary Large Objects), Hyperlink, , Text or combinations of text and numbers stored a, , Up to 8,192 (each, part of a Hyperlink, data type can, contain up to, 2048 characters)., , Lookup, , The Lookup Wizard entry in the Data Type column, in the Design view is not actually a data type. When, you choose this entry, a wizard starts to help you, , Dependent on, , define either a simple or complex lookup field., , the data type of, he lookup field., , Wizard, , A simple lookup field uses the contents of another, table or a value list to validate the contents of a, single value per row. A complex lookup field allows, you to store multiple values of the same data type, in each row., , Calculated, , You can create an expression that uses data from, , You can create, , one or more fields. You can designate different, , an expression, , result data types from the expression., , that uses data, from one or, more fields. You, can designate, different result, data types from, the expression., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , 159
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MS Access - Adding Data, , Fig 21, , Adding records to tables, , Copa 12258021, , When you enter records into your table, you are, populating the database. In Access 2007, you can do this, a few different ways., To add records in the new record row:, Click the record row with the asterisk that appears at, the bottom of the table., •, Copa 12258018, , Fig 18, , Type the data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , To add records with the New Record navigation, button:, •, , Click the New Record button in the navigation bar. The, navigation bar is located in the bottom-left corner of, the open object pane., , Fig 22, , •, , Type the new information into the field., , •, , Click outside of the record row to apply the change., , To edit a record using Find and Replace:, •, , Click the Find command in the Find group on the, Ribbon., , Fig 23, Copa 12258023, , •, , Click the cell containing the information that must be, edited. A pencil icon appears to indicate edit mode., Copa 12258022, , •, , Copa 12258019, , Fig 19, , •, , Type data into the appropriate fields., , •, , Hit Enter or the Tab key to move to the next field., , •, , The Find and Replace dialog box opens., , Fig 24, , •, , Copa 12258024, , To add records with the New Record command:, Click the New Record command in the Records group, in the Ribbon., Copa 12258020, , Fig 20, , •, , Tell Access what to find by typing it into the Find What:, area., , •, , Type the replace term in the Replace With: area., , •, , Tell Access where to look with the Look In: drop-down, list. The first choice in the drop-down list is the field, you were last in within the table., , Editing records in tables, , •, , Sometimes it is necessary to edit records in the database., Like with every other task in Access 2007, this can be, done several different ways., , Tell Access what to Match: Any part of the field, the, whole field, or just the start of the field., , •, , Tell Access how to Search: Up finds records above, the cursor, Down finds records below the cursor, and, All searches all records., , •, , Click one of the action options:, , -, , Find Next will find the next instance of the word, in the table., , •, , Type the data into the appropriate fields., , •, , Hit the Enter or the Tab key to move to the next field., , To edit a record directly:, •, , Scroll through the records, or use the navigation, buttons on the navigation bar to find the record to, edit., , 160, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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-, , Replace will put the new word into the table, overwriting, what is currently there., , -, , Cancel stops the editing process., , CAUTION: DO NOT use Replace All because it will, overwrite every instance of the Find term in the table,, which can have a serious impact on your data., To copy and paste a Record:, •, , Select the record you want to copy. Right-click, then, select Copy., , •, , Select the new record row. Right-click and select Paste., The record information appears with a new record ID, number., , To delete a record:, •, , Select the record you want to delete, then right-click, and select Delete Record., , •, , A dialog box appears, telling you the action cannot, be undone and asking if you are sure you want to, delete the record., , Let's say one of your database users has entered an order, date of January 4, 2008, in the month/date/year format as, 01/04/2008. Another user has entered an order placed on, that same date in the day/month/year format as 04/01/, 2008. If the database is tracking all sales for the month of, January 2008, it may not show both orders as placed in, January, even though both were placed on the same date., Access 2007 allows you to set field properties and data, validation rules to force the person entering data to, follow a specific format., Data types and validation rules, Data validation begins when data types are set during, the process of building tables and fields. For example, if, a field data type had been set to Currency and a text, value is entered in that table field during data entry,, Access will not accept an invalid format and will display a, validation error, like the one below., , Fig 27, , There may be other records that rely on the record you, are trying to delete. DO NOT delete a record without, knowing how it will impact the rest of your database., Fig 26, , Copa 12258027, , Copa 12258025, , Fig 25, , Data validation is accomplished by setting data validation, rules and other field properties for various fields., To set data validation rules:, •, , In Design view, highlight the field that requires a, validation rule., , •, , In the Field Properties section at the bottom half of, the window, set your validation rule using, theExpression Builder. The Expression Builder offers, common syntax to set up a data validation rule., , When you delete a record, the record number is, permanently deleted from the database table. If you, delete the last record from a table and then add a new, record, your new record numbers will appear to be out of, sequence., Data validation, Data validation is an important database concept. It is, the process by which Access tests the data that is being, entered into the database to make sure it is in an, acceptable-or valid-format., IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished, , Copa 12258028, , Copa 12258026, , Fig 28, , 161
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The image below shows the resulting error message, users would see when the Category validation rule has, been broken., , Fig 29, , Validation rules work most easily with numerical fields., Rules for text fields require you to enclose each, acceptable value inside its own quotation marks,, separating them with Or, as seen above., , Copa 12258031, , Copa 12258029, , Fig 31, , Using field properties to ensure data integrity, Another way to ensure data integrity is by setting field, properties such as Field Size, Format, and Required., •, , Validation text is a specialized error message you can, set to have Access tell the user entering data the specific, way you want that person to enter it., , Field Size can be set to hold a specific number of, characters, up to as many as 255 for text fields. If, you were using a text field to hold the two-letter state, postal abbreviation, the field size could be set to 2 to, ensure no one enters a full state name into this field., , •, , To set the validation text, enter the error message exactly, as you want it to appear to users in the row directly, beneath the Validation Rule row in the Field Properties, section of Design view. For the validation rule we set for, Category, you'd set the validation text like this:, , The Format field property can be set to display text, or numbers in a standardized way. For example, text, can be set to show as all uppercase, and numbers, can be set to show scientific numbers, percentages,, or decimals., , •, , Set the Required property to Yes if you want users, entering data to be required to enter something in, the field. Choose No if users are allowed to leave the, field blank., , Validation text, , Fig 30, , Copa 12258030, , These are just some ways Access helps you ensure data, being entered into your database is valid., , 162, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.58 - 1.9.61, , Copyright @ NIMI Not to be Republished
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IT & ITES, Related Theory for Exercise 1.9.62 to 1.9.66, COPA - Database Management Systems, Forms, quires, and reports in access, Objectives : At the end of this lesson you shall be able to, • explain database relationship and forms, • explain quires and reports in as access, In a relational database (Access), the data in one table is, related to the data in other tables. In general, tables can, be related in one of three different ways: one-to-one, oneto-many or many-to-many. The relationship is used to, cross reference information between tables., , Defining relationships, , One to One, , •, , The kind of relationship that Microsoft Access creates, depends on how the related fields are defined:, , •, , A one-to-many relationship is created if only one of, the related fields is a primary key or has a, , •, , A one-to-one relationship is created if both of the, related fields are primary keys or have unique, indexes., , •, , A many-to-many relationship is really two one-tomany relationships with a third table whose primary, key consists of two fields the foreign keys from the, two other tables., , In a one-to-one relationship each record in one table, has at most one related record in another table., In a one-to-one relationship, each record in Table A can, have only one matching record in Table B, and each, record in Table B can have only one matching record in, Table A. This type of relationship is not common, because, most information related in this way would be in one, table. You might use a one-to-one relationship to divide, a table with many fields, to isolate part of a table for, security reasons, or to store information that applies only, to a subset of the main table., , You define a relationship by adding the tables that you, want to relate to the Relationships window, and then, dragging the key field from one table and dropping it on, the key field in the other table., , One to Many, , move a table that appears in the relationship map:, , A one-to-many relationship, often referred to as a, "master-detail" or "parent-child" relationship., , •, , Place your mouse over the table you want to move., , •, , Hold down the left mouse button, then drag the table, to a new location., , •, , Release the mouse button to drop the table in its new, place., , Many to Many, In a many-to-many relationship, a record in Table A can, have many matching records in Table B, and a record in, Table B can have many matching records in Table A., This type of relationship is only possible by defining a, third table (called a junction table) whose primary key, consists of two fields the foreign keys from both Tables, A and B. A many-to-many relationship is really two oneto-many relationships with a third table., , Understanding the relationship map, The relationship map lists all of the tables that were, selected to relate, as well as all of the fields that were, previously set up for that table. Notice that the first field, has a key icon next to it. This is the primary key for the, table., , Fig 32, , A many-to-many relationship means that for each record, in one table there can be many records in another table, and for each record in the second table there can be, many in the first., , Copa 12258032, , A one-to-many relationship is the most common type of, relationship. In a one-to-many relationship, a record in, Table A can have many matching records in Table B, but, a record in Table B has only one matching record in Table, A., , Many-to-many relationships can not be directly, represented in relational database programs and have, to be built by using two or more one-to-many, relationships., , Copyright @ NIMI Not to be Republished, , 163
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Primary and foreign keys, , Bound Forms, , A primary key is the first field in each table of the, database. You may recall that this field auto-numbers, by default, so every record in the table has its own unique, number to identify it. Access uses this number to quickly, pull information together when you run queries or reports,, which are covered later., , •, , Let us now understand what Bound Forms are ?, , •, , Bound forms are connected to some underlying data, source such as a table, query, or SQL statement., , •, , Bound forms are what people typically think of when, they think of the purpose of a form., , In the example above, the primary key for the Customers, table is Customer ID, the primary key for the Orders, table is Order ID, and the primary key for the Books, table is Book ID., , •, , Forms are to be filled out or used to enter or edit data, in a database., , •, , A foreign key is a field that is the primary field in its own, table but that shows up in another table. If you look closely, at the Orders table, the fields Customer ID and Book ID, appear there, as well as in their own respective tables., These fields are the primary key in their own tables, but, in the Orders table, they are considered foreign keys., , Examples of bound forms will typically be what users, use to enter, view or edit data in a database., , Unbound Forms, , Copa 12258033, , Fig 33, , Forms, A form is a database object that you can use to enter,, edit, or display data from a table or a query. You can use, forms to control access to data, such as which fields of, data are displayed. For example, certain users may not, need to see all of the fields in a table. Providing those, users with a form that contains just the necessary fields, makes it easier for them to use the database., , Let us look into Unbound Forms:, •, , These forms are not connected to an underlying, record or data source., , •, , Unbound forms could be dialog boxes, switch boards,, or navigation forms., , •, , In other words, unbound forms are typically used to, navigate or interact with the database at large, as, opposed to the data itself., , Types of Bound Forms, There are many types of bound forms you can create in, Access. Let us understand the types ?, Single Item Form, This is the most popular one and this is where the records, are displayed - one record at a time., Multiple Item Form, This displays multiple records at a time from that bound, data source., , create a form with a single click,, , Split Form, , 1. Open the table or query upon which you want to base, theform., , The form is divided into halves, either vertically or, horizontally. One half displays a single item or record,, and the other half displays a list or provides a datasheet, view of multiple records from the underlying data source., , 2. To create a form on which all fields from the underlying, table or query are placed, displaying one record at a, time, on the Create tab, clickForm., Copa 12258034, , Fig 34, , Forms in Access are like display cases in stores that, make it easier to view or get the items that you want., Since forms are objects through which you or other users, can add, edit, or display the data stored in your Access, desktop database, the design of your form is an important, aspect. There's a lot you can do design-wise with forms, in Microsoft Access. You can create two basic types of, forms -, , Bound forms, , -, , Unbound forms, , 164, , Form Controls, Every object on a form or report is a control and has its, own set of properties (displayed in the Property list) that, determine the characteristics of the data it contains., Some controls are linked to fields in the underlying table, or query and some are merely text or graphical objects, not related to any data source. Two of the most commonly, used controls in a form or report are text boxes and labels., 1) Label: displays unchanging or informational text often, times as headings or titles. Labels do not come from a, source in the database such as a field or expression., This is called an unbound control because it is not bound, to any data source., 2) Text Box: displays data as text and is abound control.A, bound control displaysinformation that is stored in a field, from the data Text boxes are used to display, enter, and, update values from fields in your database., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Form Sections, , Item Total:[Quantity]*[Price], , Forms consist of header, footer, and detail sections. In, forms, there are two types of headers/footers. Form, headers and footers are visible on every page of the, form. Page headers/footers only appear on a printed copy, of a form. There are never visible in Form View., Information about individual records appears in the detail, sections., , Use the Expression Builder to create calculated or, concatenated fields, , Copa 12258035, , Fig 35, , Sizing Sections, Adjust the size of the area for any of the sections, (headers, footers, detail), by dragging the horizontal, border for that section with your mouse. To adjust line, spacing in the detail section, drag the Detail border. There, is no other line spacing control., Working with Queries, Queries are questions you ask of your database. They, allow you to select certain fields out of a table, or pull, together data from various related tables and display it, together. Queries can be used to perform calculations,, and to edit the data in your tables. Queries can also form, the basis of forms and reports., Query Results, •, , •, , If a query contains fields from two or more related, tables, the results will only include records that have, related records in all the tables. (In other words, in, the query shown above, customers without records, in the Orders table will not appear in the query results.), To display such records, use an outer join (see page, 6) in your query., , You can simplify the process of creating concatenated, fields and other expressions with the Expression Builder., Create a blank column in your query grid and then click, the Builder button in the Query Setup group on the Query, Design Ribbon. The Expression Builder opens., Type the expression in the large box at the top. One, advantage is that you have way more room to type and, see your expression than you have at the top of a query, grid column!, A second advantage is that you can add fields to the, expression by double clicking them in the Expression, Categories column rather than by typing them. This, removes the possibility of typos., Fig 36, , WARNING! Any change you make in a query (adding,, deleting or editing data) WILL BE CHANGED IN THE, TABLES TOO!!!, , Sort query results, , Copa 12258036, , In Design View, click the Sort row in the column you, wish to sort by. A dropdown arrow appears; choose, Ascending or Descending. If you sort by more than one, column, the sorts will be done left-to-right., Create a concatenated field in a query, Concatenated fields combine information from two or, more fields into one. Ex: Combine first and last names, into one field, called "FullName". In Design View, click, in a blank column and type the following:, FullName:[FirstName]&" "&[LastName], (Type a space between the two sets of quotation marks,, and use square brackets around the field names.), Create a calculated field in a query, , Specify criteria in a query (Filtering), In Query Design View, click in the criteria row for the, field you want to filter, and type the criteria (ex: type, "OH" in the criteria row of the State field). When you run, the query, only records matching the criteria., , In Design View, click in a blank column and type a, mathematical expression, typing field names in square, brackets. Any of the normal mathematical operators (+ * / ^) can be used. If desired, give the expression a name, as in the sample below. The following expression, calculates a total cost by multiplying quantity times price:, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 165
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Using Multiple Criteria, , Fig 37, , Copa 12258037, , You can type criteria in more than one field., •, , Criteria typed on the same line must all be met for a, record to be displayed ("AND" logic). Ex: "OH" in the, state field and "Smith" in the LastName field pulls up, only Ohio-dwelling Smiths., , •, , If criteria are typed on different lines, records matching, any of them will be retrieved ("OR" logic). Ex: "WA", and "OH" on different lines in the State field retrieves, records for both states., , Criteria Ranges, Criteria ranges broaden and customize a search. Type a, criteria range instead of a single value in the Criteria, row of the query grid., Criteria, <, , <=, , Example, , Description and Result, , <14, , Finds records where the field is less than a, certain value., Records will have values under 14., , <= #2/2/2006#, , Finds records where the field is less than, or equal to a, certain value., Records will have dates on or before February, 2, 2006, Note: dates are enclosed between # signs., , >, , >100, , Similar to above: Finds records where the, value is, , >=, , >=100, , greater than 100. The second expression displays, records where the value is greater than or, equal to 100., , =, , ="Diana", , Finds records where the value in the field is Diana., Note: text is enclosed in double quotes., , 166, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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Expressions like these may be combined - for example,, a criteria of <49 Or>=100 would return records with, values below 49, or 100 or above, but not ones with, values between 49 and 99.99., Between __ And __, , Between 1 and 4, , Finds records where the field is between, the endpoints., , Is Null, , Is Null, , Finds records where the field is empty., , Is Not Null, , Is Not Null, , Finds records where the field is not empty., , Like, , Like U*, , Finds records where the criteria match parts, of the field., , Like "[U-X]*", , The * wildcard stands for any number of, characters, and, , Like, "*Korea*", , the ?wildcard stands for a single character., , Like "*ina", , The sample criteria will return records where, the field, , Like "Chi??", , 1) starts with U; 2) starts with U, V, W or X,, 3) contains, , Like "*4.99", , the letters 'Korea'; 4) ends in the letters, 'ina' as in ballerina;, 5) has five letters and begins with the letters, 'Chi' as in Chile or China; 6) is a number and, ends in the digits '4.99' as in 24.99., , Create a parameter query, , Fig 38, , Copa 12258038, , Parameters make queries flexible by letting users choose, their own criteria each time they run the query. In the, criteria box, type a phrase in square brackets; Access, will use this phrase to prompt the user for a value. Ex: In, a State field, type [Enter a state]. If the user types CA,, only California records will be retrieved., Specify a range in a parameter query, In the criteria box, type the following:, Between [___] And [____], Inside the brackets, type text telling the user what kind, of information to enter., Inner Joins vs. Outer Joins, Excel normally uses inner joins in its queries. These, queries return only those rows from both tables in the, join that match on the joining field (e.g., customers in, the Customers table with corresponding orders in the, Orders table.), If you need to display all customers, with or without, orders, as well as any available order information, you, need to use an outer join., In the query tray, double click the join line between two, related tables. The Join Properties dialog box will appear:, , Select button 2 or 3 depending on which field's records, you want to display completely., Action Queries, Action queries modify groups of records in one fell swoop., Types of action queries include:, •, , Update Queries (modify all records in a table that, meet specific criteria - ex: change the tax rate for all, Ohio customers from 5.75% to 6%), , •, , Delete Queries (remove records from a table - ex:, delete all customers whose last order date is more, than 2 years ago), , •, , Append Queries (add records to an existing table ex: at the end of the year, add the year's orders to the, end of an archive table), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished, , 167
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•, , Make-table Queries (create a new table - ex: extract a, subset of records into a new table, for a subordinate, who needs Ohio customers only), , Other Specialized Queries, Instructions for creating and running these special query, types can be found in the Access help manual by clicking, the Help button in the upper right corner of the screen, (Internet connection required)., Find Duplicates query: Lets you locate duplicate records, in a table by displaying a field containing duplicate values, alongside other fields for comparison, to help you tell if, the record is really a duplicate., , 168, , Find Unmatched query: Lets you compare two tables, and identify records in one of the tables that have no, corresponding records in the other table., Crosstab query: This is a special type of Totals query, that presents summary information in a compact format, that is similar to a spreadsheet., Union query: Lets you review all of the data that is, returned by several similar select queries together, as a, combined set., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.9.62 - 1.9.66, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.67 - 1.10.69, , Concepts of network and internet, Objectives : At the end of this lesson you shall be able to, • define computer network and its advantages and disadvantages, • name and explain the types of network and their characteristics, • explain the types of topologies, • state about the cables used for network system, • name and state about the various connectors used in network system, • explain about the hub, modem and internet, • describe about the internet protocols connection sharing (ICS) using windows., Define computer network, , •, , A computer network is an interconnection of various, computer systems located at different places. In, computer network two or more computers are linked, together with a medium and data communication devices, for the purpose of communicating data and sharing, resources. The computer that provides resources to other, computers on a network is known as server. In the, network the individual computers, which access shared, network resources, are known as workstations or nodes., , Workgroup Computing: Workgroup software like, Microsoft BackOffice enables many users to, contribute to a document concurrently. This allows, for interactive teamwork., , •, , Error reduction and improve consistency: One, can reduce errors and improve consistency by having, all staff work from a single source of information, so, that standard versions of manuals and directories can, be made available, and data can be backed up from, a single point on a scheduled basis, ensuring, consistency., , Advantages of Computer Networks, The following are some of the advantages of computer, networks., •, , •, , •, , •, , •, , File Sharing: Networks offer a quick and easy way, to share files directly. Instead of using a disk or USB, key to carry files from one computer or office to, another, you can share files directly using a network., Security: Specific directories can be password, protected to limit access to authorized users. Also,, files and programs on a network can be designated, as "copy inhibit" so you don't have to worry about the, illegal copying of programs., Resource Sharing: All computers in the network can, share resources such as printers, fax machines,, modems, and scanners., Communication: Even outside of the internet, those, on the network can communicate with each other via, electronic mail over the network system. When, connected to the internet, network users can, communicate with people around the world via the, network., Flexible Access: Networks allow their users to access, files from computers throughout the network. This, means that a user can begin work on a project on, one computer and finish up on another. Multiple users, can also collaborate on the same project through the, network., , Network Application Areas, There is a long list of application areas, which can be, benefited by establishing Computer Networks. Few of, the potential applications of Computer Networks are:, 1 Information retrieval systems which search for books,, technical reports, papers and articles on particular, topics, 2 News access machines, which can search past news,, stories or abstracts with given search criteria., 3 Airline reservation, hotel booking, railway-reservation,, car-rental, etc., 4 A writer's aid: a dictionary, thesaurus, phrase, generator, indexed dictionary of quotations, and, encyclopaedias., 5 Stock market information systems which allow, searches for stocks that meet certain criteria,, performance comparisons, moving averages, and, various forecasting techniques., 6 Electronic Fund Transfer (EFT) between banks and via, cheque clearing house., 7 Games of the types that grow or change with various, enthusiasts adding to the complexity or diversity., 8 Electronic Mail Messages Systems (EMMS)., , Copyright @ NIMI Not to be Republished, , 169
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9 Corporate information systems such as marketing, information system, customer information system,, product information system, personnel information, system, etc., , A classification of computer networks can be done to distance as in the table., Interprocess (or), Distance, , 10 Corporate systems of different systems such as Order-Entry System, Centralized Purchasing, Distributed Inventory Control, etc., 11 On-line systems for Investment Advice and Management, Tax Minimization, etc., 12 Resources of interest to a home user., 13 Sports results., 14 Theatre, movies, and community events information., 15 Shopping information, prices, and advertisements., 16 Restaurants; good food guide., 17 Household magazine, recipes, book reviews, film reviews., 18 Holidays, hotels, travel booking., 19 Radio and TV programmes., 20 Medical assistance service., 21 Insurance information., 22 Computer Assisted Instruction (CAI)., , Network Type, , 0 to 1 Km, , Local Area Network (LAN), , 1 Km to 10 Km, , Metropolitan Area, Network (MAN), , 10 Km to 1000 Km, , Wide Area Network (WAN), , Above 1000 Km, , Internet, , Local Area Network (LAN), Networks used to interconnect computers in a single, room, rooms within a building or buildings on one site, are called Local Area Network (LAN). LAN transmits data, with a speed of several megabits per second (106 bits, per second). The transmission medium is normally coaxial cables., LAN (Fig 1) links computers, i.e., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited, geographical area because they must be connected by, a cable, which is quite expensive. People working in LAN, get more capabilities in data processing, work processing and other information exchange compared to standalone computers. Because of this information exchange, most of the business and government organisations are, using LAN., , 23 School homework, quizzes, tests., 24 Message sending service., 25 Directories., 26 Consumer reports., 27 Employment directories and Job opportunities., 28 Tax information and Tax assistance., 29 Journey planning assistance viz. Train, bus, plane, etc., , Major Characteristics of LAN, •, , every computer has the potential to communicate with, any other computers of the network, , •, , high degree of interconnection between computers, , Computer Networks may be classified on the basis of, geographical area in two broad categories., , •, , easy physical connection of computers in a network, , •, , inexpensive medium of data transmission, , 1 Local Area Network (LAN), , •, , high data transmission rate, , 2 Wide Area Network (WAN), , Types of Connection, , 30 Catalogue of Open University and Virtual University, courses., , 3 Metropolitan Area Network (MAN), , 170, , Peer to Peer: Peer to peer is an approach to computer, networking where all computers share equivalent, responsibility for processing data. Peer-to-peer, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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networking (also known simply as peer networking) differs, from client-server networking, where certain devices have, responsibility for providing or "serving" data and other, devices consume or otherwise act as "clients" of those, servers., , who sells the service to the users., 3 A MAN often acts as a high speed network to allow, sharing of regional resources. It is also frequently used, , Client server: The term client-server refers to a popular, model for computer networking that utilizes client and, server devices each designed for specific purposes. The, client-server model can be used on the Internet as well, as LAN., Advantages of LAN, •, , The reliability of network is high because the failure, of one computer in the network does not affect the, functioning for other computers., , •, , Addition of new computer to network is easy., , •, , High rate of data transmission is possible., , •, , Peripheral devices like magnetic disk and printer can, be shared by other computers., , Disadvantages of LAN, If the communication line fails, the entire network system, breaks down., Use of LAN, Followings are the major areas where LAN is normally, used, •, , File transfers and Access, , •, , Word and text processing, , •, , Electronic message handling, , •, , Remote database access, , •, , Personal computing, , •, , Digital voice transmission and storage, , to provide a shared connection to other networks using, a link to a WAN., Campus Area Network (CAN), A Campus Area Network or Corporate Area Network, (CAN) is a network is made up of an interconnection of, local area network within a limited geographical area. A, , Metropolitan Area Network (MAN), A Data network designed for a town or city. In terms of, geographic breadth, MANs are larger than, but smaller, than. MANs (Fig 2) are usually characterized by very, high-speed connections using or other digital media., Characteristic of MAN, 1 The network size falls intermediate between LANs, and WANs. A MAN typically covers an area of, between 5 and 50 km range. Many MANs cover an, area the size of a city, although in some cases MANs, may be as small as a group of buildings., 2 A MAN (like a WAN) is not generally owned by a, single organisation. The MAN, its communications, links and equipment are generally owned by either a, consortium of users or by a network service provider, , CAN (Fig 3) is larger than a local area network but smaller, than a Wide area Network, Wide Area Network (WAN), The term Wide Area Network (Fig 4) is used to describe a, computer network spanning a regional, national or global, area. For example, for a large company the head quarters, might be at Delhi and regional branches at Bombay,, Madras, Bangalore and Calcutta. Here regional centres, are connected to head quarters through WAN. The distance, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 171
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erate nationwide or even worldwide., , between computers connected to WAN is larger. Therefore, the transmission mediums used are normally telephone, lines, microwaves and satellite links., Characteristics of WAN, Followings are the major characteristics of WAN., 1 Communication Facility: For a big company, spanning over different parts of the country the, employees can save long distance phone calls and it, overcomes the time lag in overseas communications., Computer conferencing is another use of WAN where, users communicate with each other through their, computer system., 2 Remote Data Entry: Remote data entry is possible, in WAN. It means sitting at any location you can enter data, update data and query other information of, any computer attached to the WAN but located in, other cities., 3 Centralised Information: In modern computerised, environment you will find that big organisations go, for centralised data storage. This means if the, organisation is spread over many cities, they keep, their important business data in a single place. As, the data are generated at different sites, WAN permits collection of this data from different sites and, save at a single site., , •, , In LAN, the computer terminals and peripheral devices are connected with wires and coaxial cables., In WAN there is no physical connection. Communication is done through telephone lines and satellite links., , •, , Cost of data transmission in LAN is less because the, transmission medium is owned by a single, organisation. In case of WAN the cost of data transmission is very high because the transmission medium used is hired either telephone lines or satellite, links., , •, , The speed of data transmission is much higher in, LAN than in WAN. The transmission speed in LAN, varies from 0.1 to 100 megabits per second. In case, of WAN the speed ranges from 1800 to 9600 bits per, second (bps)., , •, , Few data transmission errors occur in LAN compared, to WAN. It is because in LAN the distance covered is, negligible., , Open Systems Interconnection (OSI), The Open Systems Interconnection (OSI) model is a reference tool for understanding data communications between any two networked systems. It divides the communications processes into seven layers. Each layer both, performs specific functions to support the layers above, it and offers services to the layers below it. The three, lowest layers focus on passing traffic through the network to an end system. The top four layers come into, play in the end system to complete the process., An Overview of the OSI Model (Fig 5), Application Layer (Layer 7): This layer interfaces directly to and performs common application services for, the application processes. The common application services provide semantic conversion between associated, application processes. Examples of common applica-, , Examples of WAN, 1 Ethernet: Ethernet developed by Xerox Corporation, is a famous example of WAN. This network uses coaxial cables for data transmission. Special integrated, circuit chips called controllers are used to connect, equipment to the cable., 2 Arpanet: The Arpanet is another example of WAN. It, was developed at Advanced Research Projects, Agency of U. S. Department. This Network connects, more than 40 universities and institutions throughout, USA and Europe., Difference between LAN and WAN, •, , LAN is restricted to limited geographical area of few, kilometers. But WAN covers great distance and op-, , 172, , tion services include the virtual file, virtual terminal (for, example, Telnet), and"Job transfer and Manipulation protocol" (JTM, standard ISO/IEC 8832), Presentation Layer (Layer 6): The Presentation layer, relieves the Application layer of concern regarding syntactical differences in data representation within the enduser systems. MIME encoding, encryption and similar, manipulation of the presentation of data are done at this, layer. An example of a presentation service would be, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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the conversion of an EBCDIC-coded text file to an ASCIIcoded file., Session Layer (Layer 5): The Session layer provides the, mechanism for managing the dialogue between end-user, application processes. It provides for either duplex or halfduplex operation and establishes check pointing, adjournment, termination, and restart procedures. This layer is, responsible for setting up and tearing down TCP/IP sessions., Transport Layer (Layer 4): The purpose of the Transport layer is to provide transparent transfer of data between end users, thus relieving the upper layers from, any concern with providing reliable and cost-effective, data transfer. The transport layer controls the reliability, of a given link. Some protocols are state ful and connection oriented. This means that the transport layer can, keep track of the packets and retransmit those that fail., The best known example of a layer 4 protocol is TCP., Network Layer (Layer 3): The Network layer provides, the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport layer. The Network layer performs network routing, flow control, segmentation/desegmentation, and error control functions., The router operates at this layer - sending data throughout the extended network and making the Internet possible, although there are layer 3 (or IP) switches. This is, a logical addressing scheme - values are chosen by the, network engineer. The addressing scheme is hierarchical., Data Link Layer (Layer 2): The Data link layer provides, the functional and procedural means to transfer data, between network entities and to detect and possibly correct errors that may occur in the Physical layer. The addressing scheme is physical which means that the addresses (MAC) are hard-coded into the network cards at, the time of manufacture. The addressing scheme is flat., Physical Layer (Layer 1): The physical layer defines, all electrical and physical specifications for devices. This, includes the layout of pins, voltages, and cable specifications. Hubs and repeaters are physical-layer devices., The major functions and services performed by the physical layer are:, •, , Establishment and termination of a connection to a, communications medium., , •, , Participation in the process whereby the communication resources are effectively shared among multiple users. For example, contention resolution and, flow control., , •, , Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications, , channel. These are signals operating over the physical, cabling - copper and fiber optic, for example. SCSI, operates at this level., Network Topology, The physical topology of a network refers to the configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which is the method used to pass information between workstations., Main Types of Physical Topologies, •, , LINEAR BUS, , •, , STAR, , •, , RING, , •, , TREE, , •, , MESH, , Linear Bus Topology, , A linear bus topology (Fig 6) consists of a main run of, cable with a terminator at each end. All nodes (file server,, workstations, and peripherals) are connected to the linear cable., Advantages of a Linear Bus Topology, •, , Easy to connect a computer or peripheral to a linear, bus., , •, , Requires less cable length than a star topology., , Disadvantages of a Linear Bus Topology, •, , Entire network shuts down if there is a break in the, main cable., , •, , Terminators are required at both ends of the backbone cable., , •, , Difficult to identify the problem if the entire network, shuts down., , •, , Not meant to be used as a stand-alone solution in a, large building., , Star Topology, A star topology (Fig 7) is designed with each node (file, server, workstations, and peripherals) connected directly, to a central network hub, switch, or concentrator, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 173
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Data on a star network passes through the hub, switch, or, concentrator before continuing to its destination. The hub,, switch, or concentrator manages and controls all functions of the network. It also acts as a repeater for the data, flow., This configuration is common with twisted pair cable;, however, it can also be used with coaxial cable or fiber, optic cable., Advantages of a Star Topology, •, , Easy to install and wire., , •, , No disruptions to the network when connecting or, removing devices., , •, , Easy to detect faults and to remove parts., , Disadvantages of a Star Topology, •, , Requires more cable length than a linear topology., , •, , If the hub, switch, or concentrator fails, nodes attached, are disabled., , •, , More expensive than linear bus topologies because, of the cost of the hubs, etc., , •, , There is no need for network server to control the, connectivity between workstations., , •, , Additional components do not affect the performance, of network., , •, , Each computer has equal access to resources., , Disadvantages of Ring Topology, •, , Each packet of data must pass through all the computers between source and destination., , •, , If one workstation or port goes down, the entire network gets affected., , •, , Network is highly dependent on the wire which connects different components., , •, , MAU's and network cards are expensive as compared, to Ethernet cards and hubs., , Tree or Expanded Star, A tree topology (Fig 9) combines characteristics of linear bus and star topologies. It consists of groups of starconfigured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of, an existing network, and enable schools to configure a, network to meet their needs., , Ring Topology, , Advantages of a Tree Topology, , The ring topology (Fig 8) is one which the network is a, loop where data is passed from one workstation to another., , •, , Point-to-point wiring for individual segments., , •, , Supported by several hardware and software vendors., , Advantages of Ring Topology, •, , This is very organized. Each node gets to send the, data when it receives an empty token. This helps to, reduces chances of collision. Also in ring topology all, the traffic flows in only one direction at very high, speed., , 174, , Disadvantages of a Tree Topology, •, , Overall length of each segment is limited by the type, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Disadvantages of Mesh topology, •, , There are high chances of redundancy in many of the, network connections., , •, , Overall cost of this network is way too high as compared to other network topologies., , of cabling used., , •, , •, , If the backbone line breaks, the entire segment goes, down., , Set-up and maintenance of this topology is very difficult. Even administration of the network is tough., , PROTOCOLS, , •, , More difficult to configure and wire than other topologies., , Network Protocol, , Advantages of Mesh topology, , A network protocol defines rules and conventions for, communication between network devices. Protocols for, computer networking all generally use packet switch techniques to send and receive messages in the form of, packets. Network protocols include mechanisms for devices to identify and make connections with each other,, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols, also support message acknowledgement and data compression designed for reliable and/or high-performance, network communication. Hundreds of different computer, network protocols have been developed each designed, for specific purposes and environments., , •, , Parameters of Protocol, , Mesh Topology, A network setup where each of the computers and, network devices are interconnected with one another,, allowing for most transmissions to be distributed, even, if one of the connections go down. This topology is not, commonly used for most computer networks as it is, difficult and expensive to have redundant connection to, every computer. However, this topology is commonly, used for wireless networks (Fig 10)., , •, , •, , Data can be transmitted from different devices, simultaneously. This topology can with stand high, traffic., Even if one of the components fails there is always, an alternative present. So data transfer doesn't get, affected., Expansion and modification in topology can be done, without disrupting other nodes., , 1 Physical cable or transmission media., 2 Number of bits transmitted on the media., 3 When to transmit the data on the network., 4 Volume of data to be transmitted., 5 Interact with a network with different cable type or topology., 6 Ensure that the message has been delivered intact, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 175
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Star Bus, Each computer connects to a, central connection device., , All information passes, through the, central network connection., , Each computer must be, close to the, central device., 100 meters, maximum, cable length., , Add a new, computer by, plugging in a, new cable, from, the, computer to, the connection device., , When one computer goes down,, the rest of the network is unaffected. If the connection device, goes down, then, the network is, down., , More expensive, of, the, simple topologies,, it requires, costly, connection dev i c e ., Usually, cheaper, than a hybrid network., , Uses twisted, pair cable., , To add a, c o m p u t e r,, you, must, shut down, the network, and disconnect, the, cable from, the existing, computers., , If one computer, malfunctions, the, entire network, goes down., , A cheaper, network, s i n c e, there is, usually, one continuous, copper, cable., , Single continuous cable connects the devices., , Cable between the, computers, must be broken to add a, new computer, so the, network is, down until, the new device is back, online., , If there's a break, in the cable or an, error in the network, information, continues to transfer through the, rest of the ring until reaching the, point of the break., This, makes, troubleshooting, easy., , Up to 24, computers, per network., , Requires large, amounts, of, cable. No more, than, 100, meters from, the computer to, the connection, device., , Bus, Single, cable connects everything., , One, computer at a time, sends information. Information goes, along, the, cable and the, computer accesses the information off, the cable., , Connect the, cable from, one, computer to the, next and so, on to the end., , Information, goes in one, direction, around the, ring, and, passes along, the ring until it, reaches the, correct computer., , Computers, are located, close to each, other., , A terminator, is placed at, each end of, the network., , Terminator is, required, at, each end of the, cable., Uses coaxial or, twisted pair cabling., , Ring, S i n g l e, cable configured in a, ring., , 176, , Setup, is, easy. There, is no connector., The ring has, no beginning, and no end., , One of the, more expensive, topologies, due, to, high cable, costs., , Requires more, cabling than, other topologies., Uses twisted, pair., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Network Topology Comparison, Topology, , Information, Transfer, , Setup, , Expansion, , Troubleshooting, , Cost, , Cabling, Concerns, , Hybrid, Mesh, Combines, two or more, different, structures., , Often used, across long, distances. Information, transfer can, happen in different ways,, depending on, the other topologies., , Often created, when, expanding an, existing network. Can, use a variety, of connection, devices., , Connection, devices, make combining different networks, and different, topologies, easy., , and in a proper manner., List of Network Protocols, 1 TCP/IP: Transmission Control Protocol / Internet Protocol is an industry standard protocol widely used. It is, used for inter operating among different types of computers. Almost all types of networks support TCP/IP. It is, the protocol used by the Internet. It uses a 32 - bit addressing scheme., IP Address, IP defines an addressing scheme that is independent of, the underlying physical address (e.g. 48-bit MAC address). IP specifies a unique 32-bit number for each host, on a network., , Troubleshooting is, most difficult in, this topology because of the variety of technologies., , Expens i v e ,, large,, and usually complicated., , Cabling depends on the, types of networks., Can use twisted, pair and coaxial, cable., Also incorporates fiber optic, cabling over, long distances., , FTP is built on a client-server architecture and uses separate control and data connections between the client and, the server. FTP users may authenticate themselves using, a clear-text sign-in protocol, normally in the form of a, username and password, but can connect anonymously, if the server is configured to allow it., For secure transmission that hides (encrypts) the, username and password, and encrypts the content, FTP, is often secured with SSL/TLS ("FTPS"). SSH File Transfer Protocol (SFTP) is sometimes also used instead., 4 SMTP, Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across, Internet Protocol (IP) networks., , This number is known as the Internet Protocol Address,, the IP Address or the Internet Address. These terms are, interchangeable. Each packet sent across the internet, contains the IP address of the source of the packet and, the IP address of its destination., , While electronic mail servers and other mail transfer, agents use SMTP to send and receive mail messages,, user-level client mail applications typically only use, SMTP for sending messages to a mail server for relaying., , 2 UDP - User Datagram Protocol - is a simple OSI transport layer protocol for client/server network applications, based on Internet Protocol (IP). UDP is the main alternative to TCP and one of the oldest network protocols in, existence, introduced in 1980. UDP is often used in, videoconferencing applications or computer games specially tuned for real-time performance., , For receiving messages, client applications usually use, either the Post Office Protocol (POP) or the Internet, Message Access Protocol (IMAP) or a proprietary system (such as Microsoft Exchange or Lotus Notes/, Domino) to access their mail box accounts on a mail, server., 5 Telnet, , 3 FTP: File Transfer Protocol (FTP) is a standard network protocol used to transfer files from one host or to, another host over a TCP-based network, such as the, Internet., , Telnet is a network protocol used on the Internet or local, area networks to provide a bidirectional interactive textoriented communication facility using a virtual terminal, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 177
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connection. User data is interspersed in-band with Telnet, control information in an 8-bitbyte oriented data connection over the Transmission Control Protocol (TCP)., Telnet provided access to a command-line interface (usually, of an operating system) on a remote host. Most, network equipment and operating systems with a TCP/, IP stack support a Telnet service for remote configuration (including systems based on Windows NT). Because, of security issues with Telnet, its use for this purpose, has waned in favour of SSH., 6 HTTP, , Networking Components, •, , Gateway: A device sitting at a network node for, interfacing with another network that uses different, protocols. Works on OSI layers 4 to 7., , •, , Router: A specialized network device that determines, the next network point to which it can forward a data, packet towards the destination of the packet. Unlike, a gateway, it cannot interface different protocols., Works on OSI layer 3., , •, , Switch: A device that allocates traffic from one, network segment to certain lines (intended, destination(s)) which connect the segment to another, network segment. So unlike a hub a switch splits the, network traffic and sends it to different destinations, rather than to all systems on the network. Works on, OSI layer 2., , •, , Bridge: A device that connects multiple network, segments along the data link layer. Works on OSI, layer 2., , •, , Hub: It connects multiple Ethernet segments together, making them act as a single segment. When using a, hub, every attached device shares the same, broadcast domain and the same collision domain., Therefore, only one computer connected to the hub, is able to transmit at a time., , The Hypertext Transfer Protocol (HTTP) is an application, protocol for distributed, collaborative, hypermedia, information systems. HTTP is the foundation of data, communication for the World Wide Web., Hypertext is a multi-linear set of objects, building a, network by using logical links (the so-called hyperlinks), between the nodes (e.g. text or words). HTTP is the, protocol to exchange or transfer hypertext., 7 SSH File Transfer Protocol, In computing, the SSH File Transfer Protocol (also, Secure File Transfer Protocol, Secure FTP, or SFTP) is, a network protocol that provides file access, file transfer,, and file management functionalities over any reliable, data stream., , Depending on the network topology, the hub provides, a basic level 1 OSI model connection among the, network objects (workstations, servers, etc.). It, provides bandwidth which is shared among all the, objects, compared to switches, which provide a, connection between individual nodes., , It was designed by the Internet Engineering Task Force, (IETF) as an extension of the Secure Shell Protocol, (SSH) version 2.0 to provide secure file transfer, capability, but is also intended to be usable with other, protocols., The IETF of the Internet Draft states that even though, this protocol is described in the context of the SSH-2, protocol, it could be used in a number of different, applications, such as secure file transfer over Transport, Layer Security (TLS) and transfer of management, information in VPN applications., This protocol assumes that it is run over a secure, channel, such as SSH, that the server has already, authenticated the client, and that the identity of the client, user is available to the protocol., 8 Post Office Protocol, In computing, the Post Office Protocol (POP) is an, application-layer Internet standard protocol used by local, e-mail clients to retrieve e-mail from a remote server, over a TCP/IP connection. POP and IMAP (Internet, Message Access Protocol) are the two most prevalent, Internet standard protocols for e-mail retrieval., Virtually all modern e-mail clients and servers support, both. The POP protocol has been developed through, several versions, with version 3 (POP3) being the current, standard. Most webmail service providers such as, Hotmail, Gmail and Yahoo! Mail also provide IMAP and, POP3 service., , 178, , •, , Repeater: A device to amplify or regenerate digital, signals received while sending them from one part of, a network into another. Works on OSI layer 1., , •, , Modem (MoDem): A device that modulates an analog, "carrier" signal (such as sound), to encode digital, information, and that also demodulates such a carrier, signal to decode the transmitted information, as a, computer communicating with another computer over, the telephone network, , Types of MODEM, External Modem: This is a modem separated from the, system unit in the computer case. It is connected to the, serial port of the computer by means of a cable. It is, connected to the telephone wall jack by another cable., Internal Modem: An internal modem is a circuit board, (a modem card) that can be added to the system unit of, the computer. It takes one of the expansion slots., Wired Modem / Standard Modem, Most modem’s used today are called standard modems., These modems are usually operated by commands, entered from a microcomputer keyboard. Users control, the functions (dialling, etc.) of a modem through the, keyboard. Modems may use different command, languages to control their functions,, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Wireless Modems: Wireless modems transmit the data, signals through the air instead of by using a cable. They, sometimes are called a radiofrequency modem. This type, of modem is designed to work with cellular technology,, and wireless local area networks. Wireless modems are, not yet perfected, but the technology is rapidly improving., ADSL Modem, Asymmetric Digital Subscriber Line, ADSL (Fig 11) is a, type of DSL broadband communications technology used, for connecting to the Internet. ADSL allows more data to, be sent over existing copper telephone lines POTS, when, compared to traditional modem lines. A special filter, called, a micro filter, is installed on a subscriber's telephone line, to allow both ADSL and regular voice (telephone) services, to be used at the same time. ADSL requires a special, ADSL modem and subscribers must be in close, geographical locations to the provider's central office to, receive ADSL service. Typically this distance is within a, radius of 2 to 2.5 miles. ADSL supports data rates of from, 1.5 to 9 Mbps when receiving data (known as the downstream rate) and from 16 to 640 Kbps when sending data, (known as the up- stream rate)., , Ethernet NICs plug into the system bus of the PC and, include jacks for network cables, while WI-FI NICs contain built-in transmitters / receivers (transceivers). In new, computers, many NICs are now pre-installed by the manufacturer. All NICs feature a speed rating such as 11 Mbps,, 54 Mbps or 100 Mbps that suggest the general performance of the unit., Network Cables Standards, Cable is the medium through which information usually, moves from one network device to another. There are, several types of cable which are commonly used with, LANS. In some cases, a network will utilize only one, type of cable, other networks will use a variety of cable, types. The type of cable chosen for a network is related, to the network's topology, protocol, and size. Understanding the characteristics of different types of cable and, how they relate to other aspects of a network is necessary for the development of a successful network., Cable standards, A wide range of cabling types are been used to run Ethernet, systems. Therefore, different types of cabling standards, are being used for the networks involved in connecting, devices together using different types of cabling system., , Network Interface Card (NIC), NIC (Fig. 12) provides the hardware interface between a, computer and a network. A NIC technically is network, adapter hardware in the form factor of an add-in card such, as a PCI or PCMCIA card. Some NIC cards work with, wired connections while others are wireless. Most NICs, support either wired Ethernet or WI-FI wireless standards., 12, , Coaxial cable (Fig 13) is the kind of copper cable used by, companies between the community antenna and user, homes and businesses. Coaxial cable is sometimes used, by telephone companies from their central office to the, telephone poles near users. It is also widely installed for, use in business and corporation and other types of., Coaxial cable is called "coaxial" because it includes one, physical that carries the signal surrounded (after a layer, of insulation) by another concentric physical channel,, both running along the same axis. The outer channel, serves as a ground. Many of these cables or pairs of, coaxial tubes can be placed in a single outer sheathing, and, with repeaters, can carry information for a great distance., 10BASE-T Cable Standard: 10Base-T is one of the, Ethernet standards for cabling in a network environment., 10BaseT uses a twisted pair cable with a maximum length, , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 179
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of 100 meters. Standard 10BaseT operates at 10 Mbps. It, is commonly used in a star topology., 10BASE-FL Cable Standard: 10BaseFL is a fibber optic, cable standard designed to run at 10 Mbps. It is similar, to 10Base-T, though the media type is fibber. For use up, to 2000 meters., 100BASE-TX Cable Standard: 100 Mbps Fast Ethernet, over category 5 twisted pair cable. Maximum cable length, of 100 meters., 100BASE-FX Cable Standard: 100 Mbps Fast Ethernet, standard over fibber cable. Can transmit data up to 2000, meters., 1000BASE-T Cable Standard: Gigabit Ethernet over, twisted pair copper wires. Transmit up to 1000 Mbps., 100 meter maximum cable length. Cat5 or better required, (Cat6 cabling recommended)., 1000BASE-CX Cable Standard: Gigabit Ethernet over, a special copper twinax cable. Up to 25 meters in length., Typically used in a wiring closet or data center as a short, jumper cable., , adjoining wires., The advantage of using twisted pair cables are, •, , It is lighter, thinner and more flexible, , •, , Easy to install, , •, , It is in expensive, , There are two varieties of twisted pair cabling, they are, •, , Unshielded Twisted Pair (UTP), , •, , Shielded Twisted Pair (STP), , Unshielded twisted pair (UTP), Unshielded twisted pair (Fig 14) cabling consists of two, unshielded wires twisted around each other that contain, no shielding. It is commonly used in the telephone wires, and is common for computer networking because of high, flexibility of the cables. It is a plastic connector that looks, like a large telephone-style connector. The standard connector for unshielded twisted pair cabling is RJ-45 connector., , 1000BASE-SX Cable Standard: Gigabit Ethernet using, a short-wavelength laser device over multimode fibber, optic cable. 50 μm core (max 300 meters) or 62.5 μm, core (max 500 meters). 1000Mbps maximum transfer, speed., 1000BASE-LX Cable Standard: Gigabit Ethernet using, long-wavelength laser transmitters over fibber optic, cable. Up to 3,000 meters. Uses single mode fibber and, requires SC connectors for terminating the cable., 10 GBASE-SR Cable Standard: 802.3ae standard. 33, meters for 62.5μm fibber optic cable, 300 meters for, 50μm cables. 10 Gbps (Gigabit per second) transfer rate., 10 GBASE-LR Standard: 10 Gbps transfer rate. 10, kilometres maximum distance. Fibber optic cable., , UTP has five categories of cable standards defined by the, Electronic Industries Association and Telecommunications, Industry Association (commonly known as EIA/TIA). The, five categories of unshielded twisted pair are:, Categories of Unshielded Twisted Pair, , 10 GBASE-ER Standard: 10 Gbps transfer rate. 40, kilometres maximum cable length. Fibber optic cable., , In order to manage the network cabling, you need to be, familiar with the standards that may be used on modern, networks. The categories of the unshielded twisted pair, cable are described below., , Media types, , Category 1, , A cable is a device which contains a number of signal, conductors usually in the form of separate wires. It is the, medium through which information usually moves from, one system to another through the network. There are, several types of cable which are commonly used with, the local area network. In some cases, a network utilizes, only one types of cable, whereas other network uses a, variety of cable types. The type of cable chosen for a, network is related to network topology, protocol and size., , •, , It is a form of UTP that contains two pairs of wire., , •, , CAT is suitable for voice communications but not for, data., , •, , It can carry up to 128 kilobits per second (Kbps) of, data., , •, , Twisted Pair, , It is usually used for telephone wire Data rate - 1, Mbps. This type of wire is not capable of supporting, computer network traffic and is not twisted., , Category 2, , Twisted pair cable is the most common type of network, medium used in LAN today. A transmission media consist, of colour coded pairs of two shielded insulated copper, wires which are arranged in a spiral pattern. The spiral, pattern is an important aspect of twisted - pair cables in, order to minimize cross talk of interference between, , 180, , •, , It contains four wire pairs and can carry up to 4 Mbps, of data., , •, , CAT 2 is rarely found on modern networks., , •, , Category 2 or CAT 2 is capable of transmitting data, up to 4 Mbps. This of cable is seldom used., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Category 3, •, , CAT 3 made up of four twisted - pair wires, each twist, is three times per foot. It is certified to transmit data, up to 10 Mbps., , •, , CAT 3 has typically been used for 10 Mbps Ethernet, or 4 Mbps Token Ring networks., , •, , The CAT 3 cabling is gradually replaced with CAT5 to, accommodate higher throughput., , Category 4, •, , CAT 4 is made up of four twisted-pair wires, specialized to transmit data up to 16 Mbps and is rarely is, used in new installations., , •, , CAT 4 may be used for 16Mbps Token Ring or 10, Mbps Ethernet networks. It is guaranteed for signals, as high as 20 MHz and Provides More protection, against crosstalk and attenuation than CAT1, CAT2,, orCAT 3., , The extra covering in shielded twisted pair wiring protects, the transmission line from leaking into or out of the cable., STP cabling often is used in networks, especially fast, data rate Ethernets., Fiber Optic Cable (Fig 16), , Category 5, •, , CAT 5 is the most popular twisted pair Ethernet cabling designed for high signal integrity which is in common use today., , •, , CAT 5 contains four wire pairs and supports up to, 100 Mbps throughout., , •, , It is the most popular form of UTP for new network, installations and upgrades to Fast Ethernet., , •, , In addition to 100 Mbps Ethernet, CAT 5 wiring can, support other fast networking technologies., , •, , It is popular because it is both affordable and high, speed for today's local area networks Cat 5 cables, are often used in structured cabling for computer, networks such as fast Ethernet., , Category 6, •, , •, , •, , •, , A technology that uses glass (or plastic) threads (fibers), to transmit. A fiber optic cable consists of a bundle of, glass threads, each of which is capable of transmitting, messages on to light waves., Fibre optics has several advantages over traditional metal, lines:, •, , CAT 6 cable was originally designed to support gigabit Ethernet. It is similar to CAT 5 wire, but contains a, physical separator between the four, , Fibre optic cables have a much greater than metal, cables. This means that they can carry more data., , •, , Fibre optic cables are less susceptible than metal, cables to interference., , Twisted copper wires pairs to further reduce the electromagnetic interference., , •, , Fibre optic cables are much thinner and lighter than, metal wires., , It is a twisted-pair cable that contains four wire pairs,, each wrapped in foil insulation. Additional foil insulation covers the bundle of wire pairs, and a fire-resistant plastic sheet covers the second foil layer., , •, , Data can be transmitted (the natural form for data), rather than analogically., , The foil insulation provides excellent resistance to, crosstalk and enables CAT 6 to support at least six, times the throughput supported by regular CAT 5., When the CAT 6 is used as a patch cable, it is usually, terminated in RJ-45 Electrical connectors., , Shield Twisted Pair (Fig 15), A type of copper telephone wiring in which each of the two, copper wires that are twisted together are coated with an, insulating coating that functions as a ground for the wires., , The main disadvantage of fibre optics is that the cables, are expensive to install. In addition, they are more fragile, than wire and are difficult to splice., In addition, telephone companies are steadily replacing, traditional telephone lines with fibre optic cables. In the, future, almost all communications will employ fibre optics., Straight Cable, A straight cable (Fig 17) is to connect different type of, devices. This type of cable will be used most of the time, and can be used to:, , IT & ITES : COPA - (NSQF Level - 4)- Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 181
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Rollover Cable (Fig 19), 19, , 1 Connect a computer to a switch/hub's normal port., 2 Connect a computer to a cable/DSL modem's LAN, port., 3 Connect a router's WAN port to a cable/DSL modem's, LAN port., 4 Connect a router's LAN port to a switch/hub's uplink, port. (Normally used for expanding network), 5 Connect 2 switches/hubs with one of the switch/hub, using an uplink port and the other one using normal, port., If you need to check how straight cable looks like, it's, easy. Both sides (side A and side B) of cable have wire, arrangement with same colour., Crossover Cable, A crossover cable (Fig 18), it's usually used to connect, same type of devices. A crossover cable can be used to:, , 1 Connect 2 computers directly., 2 Connect a router's LAN port to a switch/hub's normal, port. (Normally used for expanding network)., 3 Connect 2 switches/hubs by using normal port in both, switches/hubs., In you need to check how crossover cable looks like,, both side (side A and side B) of cable have wire arrangement with following different colour., , 182, , Rollover cable (also known as Cisco Console Cable or a, Yost Cable) is a type of cable that is often used to connect a computer terminal to a router's port. This cable is, typically flat (and has a light blue colour) to help distinguish it from other types of network cabling. It gets the, name rollover because the pin outs on one end are reversed from the other, as if the wire had been rolled over, and you were viewing it from the other side., Connectors, The media connectors are the physical devices that help, to transfer the data between the systems., RJ11: Registered Jack-11 (Fig 20) a four- or six-wire, used primarily to connect telephone equipment. RJ-11, connectors are also used to connect some types of some, types of Local area network., 20, , RJ45: RJ45 (Fig 21) connectors feature eight pins to which, the wire strands of a cable interface electrically. Standard, RJ-45 pinouts define the arrangement of the individual wires, needed when attaching connectors to a cable., ST: ST stands for Straight Tip (Fig 22) - a quick release, bayonet style developed by AT&T. STs were predominant, in the late 80s and early 90s., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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21, , ST Connectors are among the most commonly used fiber, optic connectors in networking applications. They are cylindrical with twist lock coupling, 2.5mm keyed ferrule. ST, connectors are used both short distance applications and, long line systems., SC: SC stands for Subscriber Connector (Fig 23) - a, general purpose push/pull style Connector developed by, NTT. SC has an advantage in keyed duplexibility to support send/receive channels., SC Connectors are frequently used for newer Network, applications. The SC is a snap-in connector that is widely, used in single mode systems for its performance. The, SC connector is also available in a Duplex configuration., They offer low cost, simplicity, and durability. SC connectors provide for accurate alignment via their ceramic ferrules., The square, snap-in connector latches with a simple, push-pull motion and is keyed. They feature a 2.5mm, Ferrule and molded housing for protection. Typical matched, SC connectors are rated for 1000 mating cycles and have, an Insertion Loss of 0.25 dB., , USB: The USB 2.0 Standard-A type of USB plug is a, flattened rectangle which inserts into a "downstream-port", receptacle on the USB host, or a hub, and carries both, power and data. This plug is frequently seen on cables, that are permanently attached to a device, such as one, connecting a keyboard or mouse to the computer via, USB connection., A Standard-B plug-which has a square shape with bevelled exterior corners-typically plugs into an "upstream, receptacle" on a device that uses a removable cable,, e.g. a printer. A Type B plug delivers power in addition to, carrying data. On some devices, the Type B receptacle, has no data connections, being used solely for accepting, power from the upstream device. This two-connector-type, scheme (A/B) prevents a user from accidentally creating, an Electrical loop., BNC: Bayonet Neill Concelman (Fig 25) connector,, (sometimes erroneously called a British Naval Connector, or Bayonet Nut Connector, a type of connector used with, coaxial cable such as the RG-58 A/U cable used with the, 10Base2. The basic BNC connector is a male type, mounted at each end of a cable., , LC: LC stands for Lucent Connector (Fig 24). The LC is, a small form factor fiber optic connector., The LC Connector uses a 1.25 mm ferrule, half the size of, the ST. Otherwise, it is a standard ceramic Ferrule connector. The LC has good performance and is highly favoured, for single mode., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 183
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This connector has a center pin connected to the center, cable conductor and a metal tube connected to the outer, cable shield. A rotating ring outside the tube locks the, cable to any female connector., BNC T-connectors (used with the 10Base-2 system) are, female devices for connecting two cables to a NIC. A, BNC barrel connector allows connecting two cables together., BNC connectors can also be used to connect some, monitor, which increases the accuracy of the signals sent, from the adapter., Crimping Tool: A crimping tool (Fig 26) is a tool designed to crimp or connect a connector to the end of a, cable. For example, network cables and phone cables, are created using a crimping tool to connect the RJ45 and, RJ11 connectors to the end of the cable. In the picture to, the right, is an example of what a crimping tool looks like., This shows a tool capable of crimping both RJ-11 and RJ45 connectors., , 5 Arrange the untwisted wires in a row, placing them, into the position, running from right to left, in which, they will go into the RJ-45 connector:, •, , Orange with a white stripe, , •, , Orange, , •, , Green with a white stripe, , •, , Blue, , •, , Blue with a white strip, , •, , Green, , •, , Brown with a white stripe, , •, , Brown, , 6 Trim the untwisted wires to a suitable length by holding the RJ-45 connector next to the wires. The insulation on the cable should be just inside the bottom, of the RJ-45 connector. The wires should be trimmed, so that they line up evenly with the top of the RJ-45, connector., •, , Trim the wires in small increments, checking frequently to ensure a correct fit. It's better to cut the, untwisted wires a few times than have to go back, and start all over again because you trimmed off, too much., , 7 Insert the wires into the RJ-45 connector, making sure, that they stay aligned and each color goes into its, appropriate channel. Make sure that each wire goes, all the way to the top of the RJ-45 connector. If you, don't make these checks, you will find that your newly, crimped RJ-45 connector is useless., 8 Use the crimping tool to crimp the RJ-45 connector, to the cable by pressing the jacket and cable into the, connector so that the wedge at the bottom of the connector is pressed into the jacket., Re crimp the cable once more to ensure proper connection., , How to Crimp RJ45, 1 Strip 1 to 2 inches (2.5 to 5.1 cm) of the outer skin at, the end of the cable wire by making a shallow cut in, the skin with a utility knife. Run the knife around the, cable, and the jacket should slide off easily. There will, be 4 pairs of twisted wires exposed, each of them a, different color or colour combination., Orange-white striped and solid orange, Green-white striped and solid green, Blue-white striped and solid blue, Brown-white striped and solid brown, 2 Fold each pair of wires backwards to expose the core, of the cable., 3 Cut off the core and discard., , 9 Follow the instructions above to crimp an RJ-45 connector to the opposite end of the cable, 10 Use a cable tester to assure that your cable is working properly when both ends are crimped., Cable Tester (Fig 27), When connected to an Ethernet cable, a network cable, tester tells if the cable is capable of carrying an Ethernet, signal. If the cable carries the signal, this indicates that, all the circuits are closed, meaning that electric current, can move unimpeded through the wires, and that there, are no short circuits, or unwanted connections, in the wire., Network cable testers vary in complexity and price, but a, basic tester consists of a source of electrical current, a, measuring device that shows if the cable is good, and a, connection between the two, usually the cable itself., , 4 Straighten the twisted wires using 2 pair of tweezers., Grasp a wire beneath a bend with 1 pair of tweezers,, and use the other pair to gently straighten the bend., The straighter your wires, the easier your job will be, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, 184, , Copyright @ NIMI Not to be Republished
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Switch, A Network Switch (Fig 28) is a small hardware device, that joins multiple computers together within one Local, Area Network. Technically, network switches operate at, layer two (Data Link Layer) of the OSI., 28, , Computer networks use Ethernet cables to allow computers in the network to "talk" to each other. An Ethernet, cable has eight wires that are arranged in four pairs. For, current to flow correctly, the wire pairs must be connected, in the proper order., A network cable tester can identify if the wires are paired, correctly. It can also show if there is a break in the insulation, a situation which allows crosstalk between two, wires that should not be connected. The tester can also, tell whether the cable has the proper level of resistance., A network cable tester can be a simple apparatus that, merely identifies whether current flows through the cable,, or it may be a professional-level, complex device that, gives additional information that helps identify the problem., Professional-level network cable testers may not only, tell if an open circuit exists, but may identify where the, break is located. Some also identify the gauge of wire, used and can generate their own signal to test for interference., How to Check with the Tester, , Network switches appear nearly identical to hub, but a, switch generally contains more intelligence (and a slightly, higher price tag) than a hub. Unlike hubs, network switches, are capable of inspecting data packet as they are received,, determining the source and destination device of each, packet, and forwarding them appropriately., By delivering messages only to the connected device intended, a network switch conserves bandwidth and offers, generally better performance than a hub., Availability of Switches, 1 8 Port Switches, 2 16 port switches, 3 24 port switches, 4 32 port switches, Hub: A Hub (Fig 29) is a small, simple, inexpensive, device that joins multiple computers together. Many, network hubs available today support the Ethernet, standard. Other types including USB hubs also exist, but, Ethernet is the type traditionally used in home networking., To network a group of computers using an Ethernet hub,, 29, , 1 Turn on your network cable tester., 2 Plug one end of the Ethernet cable you are trying to, test into the "IN" Ethernet input on the network cable, tester., 3 Plug the other end of your Ethernet cable you are, trying to test into the "OUT" input on the network cable, tester., 4 Press the "Test" button. The network cable tester will, send a signal across the Ethernet cable. If the signal, gets from one end of the cable to the other, a green, light will appear on the device, letting you know that, the test was successful. If the signal does not get, from one end of the cable to the other, a red light will, appear on the device, letting you know that the test, was not successful and that the cable is bad., , first connect an Ethernet cable into the unit, and then, connect the other end of the cable to each computer's, NIC. All Ethernet hubs accept the RJ45 connectors of standard Ethernet cables., Ethernet hubs vary in the speed (network data rate or, bandwidth they support. Some years ago, Ethernet hubs, offered only 10 Kbps rated speeds. Newer types of hubs, offer 100 Mbps Ethernet. Some support both 10 Mbps, and 100 Mbps (so-called dual-speed or 10/100 hubs)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 185
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Routers, Routers (Fig 30) are physical devices that join multiple, wired or wireless networks together. Technically, a wired, or wireless router is a Layer 3 gateway, meaning that the, wired/wireless router connects networks (as gateways do),, and that the router operates at the network layer of the, OSI model., , monthly fee for this equipment that is added to your ISP, account billing., In addition to serving individuals, ISPs also serve large, companies, providing a direct connection from the, company's networks to the Internet. ISPs themselves, are connected to one another through Network Access, Point (NAPs). ISPs may also be called IAPs (Internet, Access Provider)., State Owned ISP's, •, , BSNL - Servicing all of India except Mumbai and, Delhi. Triple-play Broadband Services provided by, ADSL and VDSL. Also providing internet services over, GPRS, 3G, as well as WiMax, , •, , MTNL - Servicing Mumbai and Delhi. Triple-play, Broadband Services provided by ADSL under the "TriBand" brand. Also providing GPRS and 3G internet, services., , Private Owned nationwide ISP's, •, , Airtel - ADSL, GPRS, 3G & 4G LTE, , Home networkers often use an Internet Protocol (IP), wired or wireless router, IP being the most common OSI, network layer protocol. An IP router such as a DSL or, cable modem router joins the home's LAN to the WAN, of the Internet., , •, , Skynet Broadband - Internet Service Provider, , •, , Aircel - GPRS & 3G, , •, , Hathway - Broadband over Cable, , •, , Idea - GPRS & 3G, , Bridges, , •, , MTS India - CDMA/EV-DO, , A bridge (Fig 31) device filters data traffic at a network, boundary. Bridges reduce the amount of traffic on a LAN, by dividing it into two segments., , •, , O-Zone Networks Private Limited - Pan - India Public Wi-Fi hotspot provider, , •, , Reliance Communications - ADSL, GPRS & 3G,, Metro-Ethernet, CDMA/EV-DO, Wimax, , •, , Reliance Industries - LTE (to be launched), , •, , Sify - Broadband over cable, , •, , Tata DoCoMo - GPRS & 3G, , •, , Tata Indicom - ADSL, CDMA/EV-DO, Metro-Ethernet,, WiMax, , •, , Vodafone - GPRS & 3G, , 31, , Bridges operate at the data link layer (Layer 2) of the OSI, model. Bridges inspect incoming traffic and decide whether, to forward or discard it. An Ethernet bridge, for example,, inspects each incoming Ethernet frame - including the, source and destination MAC addresses, and sometimes, the frame size - in making individual forwarding decisions., ISP: Internet Service Provider, it refers to a company that, provides Internet services, including personal and business access to the internet. For a monthly fee, the service provider usually provides a software package,, Username, password and access phone number., Equipped with a modem you can then log on to the, Internet and browse the world wide web and USENET, and send and receive email For broadband access you, typically receive the broadband modem hardware or pay a, , 186, , NSP: Network Service Providers (NSP) is a business or, organization that sells bandwidth or network access by, providing direct Internet backbone access to the Internet, and usually access to its Network Access Point (NAPs)., Network service providers may consist of Telecommunications companies, data carriers, wireless communications providers, Internet service provider, and Cable television operators offering high-speed Internet access., Dial up: Dial-up access is really just like a phone connection, except that the parties at the two ends are computer devices rather than people. Because dial-up access, uses normal telephone lines, the quality of the connection, is not always good and data rate are limited., In the past, the maximum data rate with dial-up access, was 56 Kbps (56,000 bits per second), but new technologies such as ISDN are providing faster rates., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished
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Broadband: The term broadband refers to a telecommunications signal or device of greater Bandwidth (signal processing), in some sense, than another standard or usual, signal or device (and the broader the band, the greater the, capacity for traffic)., Wireless (Wi-Fi): Wireless broadband is high-speed, Internet service via wireless technology. Wireless broadband is available in Internet cafés, local "hot spots" within, many cities, private businesses and many homes., The advantage of wireless broadband is that the computer receiving the Internet signal need not be tethered, by an Ethernet or network cable to the broadband modem or router., , A wireless broadband modem receives the service and, transmits it via radio waves to the immediate surrounding area. Any computer equipped with wireless capacity, within receiving distance can pick up the signal, making, the Internet 'portable.' The most common way to take, advantage of wireless broadband is by using a laptop, computer., Mobile Broadband: The term mobile broadband refers, to high-speed wireless Internet connections and services, designed to be used from arbitrary locations., Cellular networks normally provide broadband connections suitable for mobile access. The technologies in use, today fall into two categories -3G (third generation cell, networks) and 4G (fourth generation)., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.67 - 1.10.69, , Copyright @ NIMI Not to be Republished, , 187
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.70, , Introduction to TCP/IP, Objectives : At the end of this lesson you shall be able to, • explain TCP/IP, addresses and subnets., Introduction to TCP/IP : TCP and IP were developed by, Department of Defense (DOD) research project to connect, a number different networks designed by different vendors, into a network of networks (the “Internet”). It was initially, usccessful because it delivered a few basic services that, everyone needs (file transfer, electronic mail, remote, logon) across a very large number of client and server, systems. Several computers in a small department can, use TCP/IP (along with other protocols) on a single LAN., The IP component provides routing from the department, to the enterprise network, then to regional networks, and, finally to the global internet. On the battlefield a, communications network will sustain damage, so the, DOD designed TCP/IP to be robust and automatically, recover from any node or phone failure. This design, allows the construction of very large networks with less, central management. However, because of the automatic, recovery, network problems can go undiagnosed and, uncorrected for long periods of time., As with all other communications protocol, TCP/IP is, composed of layers:, IP is responsible for moving packet of data from node to, node. IP forwards each packet based on a four byte, destination address (the IP number). The Internet, authorities assign ranges of numbers to different, organisations. The organisations assign groups of their, numbers to departments. IP operates on gateway, machines that move data from department to organisation, to region and then around the world., TCP is responsible for verifying the correct delivery of, data from client to server. Data can be lost in the, intermediate network. TCP adds support to detect errors, or lost data and to trigger retransmission until the data is, correctly and completely received., Sockets is a name given to the package of subroutines, that provide access to TCP/IP on most systems., The Internet Protocol was developed to create a Network, of Networks (the “Internet”). Individual machines are first, connected to a LAN (Ethernet or Token Ring). TCP/IP, shares the LAN with other users (a Novell file server,, Windows for Workgroups peer systems). One device, provides the TCP/IP connection between the LAN and, the rest of the world. (Refer Fig 1), To insure that all types of systems from all vendors can, communicate, TCP/IP is absolutely standardised on the, LAN. However, larger networks based on long distances, and phone lines are more volatile. In US, many large, corporations would wish to reuse large internal networks, based on IBM’s SNA. In Europe, the national phone, 188, , companies traditionally standardize on X.25. However,, the sudden explosion of high speed microprocessors,, fiber optics and digital phone systems has created a burst, of new options: ISDN, frame relay, FDDI, Asynchronous, Transfer Mode (ATM). New technologies arise and, become obsolete within a few years. With cable TV and, phone companies competing to built the National, Information Superhighway, no single standard can govern, citywide, nationwide, or worldwide communications., The original design of TCP/IP as a Network of Networks, fits nicely within the current technological uncertainty., TCP/IP data can be sent across a LAN or it can be carried, within an internal corporate SNA network or it can, piggyback on the cable TV service. Furthermore,, machines connected to any of these networks can, communicate to any other network through gateways, supplied by the network vendor., Addresses : Each technology has its own convention for, transmission messages between two machines within, the same network. On a LAN, messages are sent between, machines by supplying the six byte unique identifier (the, “MAC” address). In an SNA network, every mahine has, Logical Units with their own network address. DECNET,, Appletalk and Novell IPX all have a scheme for assigning, numbers to each local network and to each workstation, attached to the network., On top of these local or vendor specific network addresses,, TCP/IP assigns a unique number to every workstation in, the world. This “IP number” is a four byte value that, by, convention, is expressed by converting each byte into a, decimal number (0 to 255) and separating the bytes with, a period. For example, a server IP is like 130.132.59.234, Subnets: Although the individual subscribers do not, need to tabulate network numbers or provide explicit, routing, it is convenient for most Class B networks to be, internally manage as much smaller and simpler version, , Copyright @ NIMI Not to be Republished
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of the larger network organisations. It is common to, subdivide the two bytes available for internal assignment, into a one byte department number and a one byte, workstation ID. (Refer Fig 2), , There are three levels of TCP/IP knowledge. Those who, administer a regional or national network must design a, system of long distance phone lines, dedicated routing, devices and very large configuration files. They must, know the IP numbers and physical locations of thousands, of subscriber networks. They must also have a formal, network monitor strategy to detect problems and respond, quickly., Each large company or university that subscribes to the, Internet must have an intermediate level of network, organisation and expertise. A half dozen routers might be, configured to connect several dozen departmental LANs, in several buildings. All traffic outside the organisation, would typically be routed to a single connection to a, regional network provider., However, the end user can install TCP/IP on a personal, computer without any knowledge of either the corporate, or regional network. Three pieces of information are, required:, , The enterprise network is built using commercially, available TCP/IP router boxes. Each router has small, tables with 255 entries to translate the one byte department, number into selection of a destination Ethernet connected, to one of the routers., TCP treats the data as a stream of bytes. It logically, assigns a sequence number to each byte. The TCP, packet has a header that says, in effect, “This packet, starts with byte 379642 and contains 200 bytes of data.”, The receiver can detect missing or incorrectly sequenced, packets. TCP acknowledges data that has been received, and retransmits data that has been lost. The TCP design, means that error recovery is done end-to-end between, the Client and Server machine. There is no formal, standard for tracking problems in the middle of the, network, though each network has adopted some adhoc, tools., , 1 The IP address assigned to this personal computer., 2 The part of the IP address (the subnet mask) that, distinguishes other machines on the same LAN, (messages can be sent to them directly) from machines, in other departments or elsewhere in the world (which, are sent to a router machine), 3 The IP address of the router machine that connects, this LAN to the rest of the world., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.70, , Copyright @ NIMI Not to be Republished, , 189
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IT & ITES, Related Theory for Exercise 1.10.71 to 1.10.72, COPA - Networking Concepts, Transmission media and network components, Objectives :At the end of this lesson you shall be able to, • explain cable media, wireless media and network adapter., Network media : Media are what the message is, transmitted over. Different media have different properties, and are most effectively used in different environments, for different purposes., In computer networking, the medium affects nearly every, aspect of communication. Most important, it determines, how quickly and to whom a computer can talk and how, expensive the process is., , Cable media : Cables have a central conductor that, consists of a wire or fiber surrounded by a plastic jacket., Three types of cable media are twisted-pair, coaxial and, fiber-optic cable. Two types of twisted-pair cable are, used in networks: unshielded (UTP) and shielded (STP)., Table summarizes the characteristics of these types of, cable media, which are discussed in the following sections., , Factor, , UTP, , STP, , Coaxial, , Fiber-optic, , Cost, , Lowest, , Moderate, , Moderate, , Highest, , Installation, , Easy, , Fairly easy, , Fairly easy, , Difficult, , Bandwidth, capacity, , 1- to 155 Mbps, (typically 10 Mbps), , 1- to 155Mbps, (typically 16 Mbps), , Typically, 10 Mbps, , 2 Gbps, (typically 100 Mbps), , Node capacity, per segment, , 2, , 2, , 30 (10base 2), 100 (10 base 5), , 2, , Attenuation, , High (range of, hundreds of meters), , High (range of, hundreds of, meters), , Lower (range of a few, kilometers), , Lowest (range of, tens of kilometers), , EMI, , Most vulnerable to, EMI and, eavesdropping, , Less vulnerable, than UTP but still, vulnerable to EMI, and eavesdropping, , Less vulnerable than, UTP but still vulnerable, to EMI and, eavesdropping, , Not affected by, EMI or, eavesdropping, , Twisted-pair cable : Twisted-pair cable uses one or more, pairs of two twisted copper wires to transmit signals. It is, commonly used as telecommunications cable., When copper wires that are close together conduct, electric signals, there is a tendency for each wire to, produce interference in the other. One wire interferring, with another in this way is called crosstalk. To decrease, the amount of crosstalk and outside interference, the, wires are twisted. Twisting the wires allows the emitted, signals from one wire to cancel out the emitted signals, from the other and protects them from outside noise., Twisted pairs are two color-coded, insulated copper, wires that are twisted around each other. A twisted-pair, cable consists of one or more twisted pairs in a common, jacket. Fig 1 shows a twisted-pair cable., The two types of twisted-pair cable are unshielded and, shielded., 190, , Unshielded twisted-pair cable : Unshielded twistedpair (UTP) cable consists of a number of twisted pairs, with a simple plastic casing. UTP is commonly used in, telephone systems. Fig 2 shows a UTP cable., The Electrical Industries Association (EIA) divides UTP, into different categories by quality grade. The rating for, each category refers to conductor size, electrical characteristics and twists per foot. The following categories are, defined., , Copyright @ NIMI Not to be Republished
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The other side of the punch-down block is wired to a patch, panel. The patch panel provides connectivity through, patch cables to other user devices and connectivity, devices., UTP’s popularity is partly due to the, first usage of the, same in telephone systems. In many cases a network can, be run over the already existing wires installed for the, phone system, at a great savings in installation cost., , – Categories 1 and 2 were originally meant for voice, communication and can support only low data rates,, less than 4 megabits per second (Mbps). These, cannot be used for high-speed data communications., Older telephone networks used Category 1 cable., , Shielded twisted-pair cable : The only difference between shielded twisted pair (STP) and UTP is that STP, cable has a shielded usually aluminium/polyester between, the outer jacket or casing and the wires. Fig 4 shows STP, cable., , – Category 3 is suitable for most computer networks., Some innovations can allow data rates much higher,, but generally Category 3 offers data rates up to 16, Mbps. This category of cable is the kind currently used, in most telephone installations., – Category 4 offers data rates upto 20 Mbps., – Category 5 offers enhancements over Category 3,, such as support for Fast Ethernet, more insulation, and more twists per foot, but Category 5 requires, compatible equipment and more stringent installation., In a Category 5 installation, all media, connectors and, connecting equipment must support Category 5 or, performance will be affected., Data-grade UTP cable (Categories 3,4 and 5) consists of, either four or eight wires. A UTP cable with four wires is, called a two-pair. Network topologies that use UTP, require atleast two-pair wire. You may want to include an, extra pair for future expansion. Fig 3 shows a four-pair, cable., , Because UTP cable was originally used in telephone, systems, UTP installations are often similar to telephone, installations. For a four-pair cable, you need a modular, RJ-45 telephone connector. For a two-pair cable, you, need a modular RJ-11 telephone connector. These, connectors are attached to both ends of a patch cable., One end of the patch cable is then inserted into a, computer or other device, and the other end is inserted, into a wall jack. The wall jack connects the UTP drop, cable (another length of cable) to a punch-down block., , The shield makes STP less vulnerable to EMI because, the shield is electrically grounded. If a shield is grounded, correctly, it tends to prevent signals from getting into or, out of the cable. It is a more reliable cable for LAN, environments. STP was the first twisted-pair cable to be, used in LANs. Although many LANs now use UTP, STP, is still used., Transmission media specifications from IBM and Apple, Computer use STP cable. IBM’s Token Ring network, uses STP and IBM has its own specifications for different, qualities and configurations of STP. A completely different, type of STP is the standard for Apple’s Apple Talk, networks. Networks that confirm to each vendor’s specifications have their own special requirements, including, connector types and limits on cable length., STP has the following characteristics, Cost : Bulk STP is fairly expensive. STP costs more than, UTP and thin coaxial cable but less than thick coaxial or, fiber-optic cabling., Installation : The requirement for special connectors, can make STP more difficult to install than UTP. An, electrical ground must be created with the connectors. To, simplify installation, use standardised and prewired cables., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 191
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Because STP is rigid and thick (up to 1.5 inches in, diameter), it can be difficult to handle., , The following are some coaxial cables commonly used in, networking:, , Bandwidth capacity : With the outside interference, reduced by the shielding, STP can theoretically run at, 500 Mbps for a 100 meter cable length. Few installations, run at data rates higher than 155 Mbps. Currently, most, STP installations have data rates of 16 Mbps., , 50 ohm, RG-8 and RG-11 used for thick ethernet., , Node capacity : Since only two computers can be, connected together by an STP cable, the number of, computers in an STP network is not limited by the cable., Rather, it is limited by the hub or hubs that connect the, cables together. In a Token Ring network, which is the, most common type of STP network, the useful upper limit, is around 200 nodes in a single ring, but it depends on the, type of data traffic in your network. There is a specified, maximum limit of 270, but you will probably never reach, this limit., , PVC and plenum cable : Polyvinyl chloride (PVC) is, commonly used in coaxial cabling because it is a flexible,, inexpensive plastic well suited for use as insulation and, cable jacketing. PVC is often used in the exposed areas, of an office., , Attenuation : STP does not outperform UTP by much in, terms of attenuation. The most common limit is 100, meters., EMI : The biggest different between STP and UTP is the, reduction of EMI. The shielding blocks a considerable, amount of the interference. However, since it is copper, wire, STP still suffers from EMI and is vulnerable to, eavesdropping., Coaxial cable : Coaxial cable commonly called coax, has two conductors that share the same axis. A solid, copper wire or stranded wire runs down the center of the, cable and this wire is surrounded by plastic foam insulation., The form is surrounded by a second conductor, a wire, mesh tube, metallic foil or both. The wire mesh protects, the wire from EMI. It is often called the shield. A tough, plastic jacket forms the cover of the cable, providing, protection and insulation. Fig 5 shows a coaxial cable., , 50 ohm, RG-58 used for thin ethernet., 75 ohm, RG-59 used for cable TV., 93 ohm, RG-62 used for ARCnet., , A plenum is the space between the false ceiling of an, office and the floor above. The air in the plenum circulates, with the air in the rest of the building, and there are strict, fire codes about what can be placed in a plenum, environment., Because PVC gives off poisonous gases when burned,, you cannot use it in a plenum environment. You must use, plenum grade cable instead. Plenum grade cable is, certified to be fire resistant to produce a minimum, amount of smoke. Plenum cable is also used in vertical, runs (walls) without conduit (a tube to hold the cable)., Plenum cable is more expensive and less flexible than, PVC., Fiber-optic cable : Fiber-optic cable transmits light, signals rather than electrical signals. It is enormously, more efficient than the other network transmission media., As soon as it comes down in price (both in terms of the, cable and installation costs) fibre optic will be the choice, for network cabling., Each fiber has an inner core of glass or plastic that, conducts light. The inner core is surrounded by cladding,, a layer of glass that reflects the light back into the core., Each fiber is surrounded by a plastic sheath. The sheath, can be either tight or loose. Fig 6 shows examples of, these two types of fiber optic cables., , Coaxial cable comes in different sizes. It is classified by, size (RG) and by the cable’s resistance to direct or, alternating electric currents (measured in ohms also, called impedance), 192, , Tight configurations completely surround the fibers with, a plastic sheath and sometimes include wires to strengthen, the cable (although these wires are not required). Loose, configurations leave a space between the sheath and the, IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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outer jacket, which is filled with a gel or other material., The sheath provides the strength necessary to protect, against breaking or extreme heat or cold. The gel,, strength wires and outer jacket provide extra protection., A cable may contain a single fiber, but often fibers are, bundled together in the center of the cable. Optical fibers, are smaller and lighter than copper wire. One optical fiber, is approximately the same diameter as a human hair., Optical fibers may be multimode or single mode. Single, mode fibers allow a single light path and are typically, used with laser signaling. Single mode fiber can allow, greater bandwidth and cable runs than multimode but is, more expensive. Multimode fibers use multiple light, paths. The physical characteristics of the multimode, fiber make all parts of the signal (those from the various, paths) arrive at the same time, appearing to the receiver, as though they were one pulse. If you want to save, money, look into multimode, since it can be used with, LEDs (light emitting diodes) which are a more affordable, light source than lasers. Fig 7 shows single mode and, multi mode fibers., , bounded media difficult. There are three main types of, wireless media: radio wave, micro wave and infrared., Radio wave transmission systems : Radio waves, have frequencies between 10 kilohertz (KHz) and 1, gigahertz (GHz). The range of the electromagnetic, spectrum between 10 KHz and 1 GHz is called radio, frequency (RF)., Radio wave include the following types., Short wave, Very high frequency (VHF) television and FM radio, Ultra-high frequency (UHF) radio and television, Radio waves can be broadcast omnidirectionally or, directionally. Various kinds of antennas can be used to, broadcast radio signals., Microwave transmission systems : Microwave communication makes use of the lower gigahertz frequencies, of the electromagnetic spectrum. These frequencies,, which are higher than radio frequencies, produce better, throughout and performance. There are two types of, microwave data communication systems: terrestrial and, satellite., Terrestrial microwave : Terrestrial microwave systems, typically use directional parabolic antennas to send and, receive signals in the lower gigahertz range. The signals, are highly focused and the physical path must be line-ofsight. Relay towers are used to extend signals. Terrestrial, microwave systems are typically used when using cabling, is cost prohibitive., Because terrestrial microwave equipment often uses, licensed frequencies, additional costs and time constraints, may be imposed by licensing commissions or government, agencies (the FCC, in the United States)., , Optical fibers are differentiated by core/cladding size, and mode. The size and purity of the core determine the, amount of light that can be transmitted. The following are, the common types of fiber-optic cable., 8.3 micron core/125 micron cladding, single mode, 62.5 micron core/125 micron cladding, multimode, 50 micron core/125 micron cladding, multimode, 100 micron core/140 micron cladding, multimode, A typical LAN installation starts at a computer or network, device that has a fiber-optic network interface and (NIC)., This NIC has an incoming interface and an outgoing, interface. The interfaces are directly connected to fiberoptic cables with special fibre-optic connectors. The, opposite ends of the cables are attached to a connectivity, device or splice center., Wireless media : Wireless media do not use an electrical, or optical conductor. In most cases, the earth’s atmosphere is the physical path for the data. Wireless media is, therefore useful when distance or obstructions make, , Fig 8 shows a microwave system connecting separate, buildings. Smaller terrestrial microwave systems can be, used within a building, as well. Microwave LANs operate, at low power, using small transmitters that communicate, with omnidirectional hubs. Hubs can then be connected, to form an entire network., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 193
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Satellite : Satellite microwave systems transmit signals, between directional parabolic antennas. Like terrestrial, microwave systems, they use low gigahertz frequencies, and must be in line-of-sight. The main difference with, satellite system is that one antenna is on a satellite in, geosynchronous orbit about 50,000 kilometers (22,300, miles) above the earth. Because of this, satellite microwave systems can reach the most remote places on earth, and communicate with mobile devices., Here’s how it usually works: a LAN sends a signal, through cable media to an antenna (commonly known as, a satellite dish), which beams the signal to the satellite in, orbit above the earth. The orbiting antenna then transmits, the signal to the another location on the earth or, if the, destination is on the opposite side of the earth, to another, satellite, which then transmits to a location on earth., Fig 9 shows a transmission being learned from a satellite, dish on earth to an orbiting satellite and then back to, earth., , Because the signal must be transmitted 50,000 kilometers, to the satellite and 50,000 kilometers back to earth,, satellite microwave transmissions take about as long to, cover a few kilometers as they do to span continents., Because the transmission must travel long distances,, satellite microwave systems experience delays between, the transmission of a signal and its reception. These, delays are called propagation delays. Propagation delays, range from .5 to 5 seconds., Infrared transmission systems : Infrared media use, infrared light to transmit signals. LEDs or ILDs transmit, the signals and photodiodes receive the signals. Infrared, media use the tera-hertz range of the electromagnetic, spectrum. The remote controls we use for television,, VCR and CD players use infrared technology to send and, receive signals., , Infrared media use pure light, normally containing only, electromagnetic waves or photons from a small range of, the electromagnetic spectrum. Infrared light is transmitted, either line-of-sight (point-to-point) or broadcast, omnidirectionally, allowing it to reflect off walls and, ceilings. Point-to-point transmission allows for better, data rates, but devices must remain in their locations., Broadcast, on the other hand, allows for more flexibility, but with lower data rates. (Part of the signal strength is, lost with each reflection.), Point-to-point : Infrared beams can be tightly focused, and directed at a specific target. Laser transmitters can, transmit line-of-sight across several thousand meters., One advantage of infrared is that an FCC license is not, required to use it. Also, using point-to-point infrared, media reduces attenuation and makes eavesdropping, difficult. Typical point-to-point infrared computer, equipment is similar to that used for consumer product, with remote controls. Careful alignment of transmitter, and receiver is required. Fig 10 shows how a network, might use point-to-point infrared transmission., , Broadcast : Broadcast infrared systems spread the, signal to cover a wider area and allow reception of the, signal by several receivers. One of the major advantage, is mobility; the workstations or other devices can be, moved more easily than with point-to-point infrared, media. Fig 11 shows how a broadcast infrared system, might be used., Because broadcast infrared signals are not as focussed, as point-to-point, this type of system cannot offer the, same throughout. Broadcast infrared is typically limited, to less than 1 Mbps, making it too slow for most network, needs., Network adapters, sometimes called Network Interface, Cards (NICs) are peripheral cards that plug into the, motherboard of your computer and into a network cable., It is through the network adapter that your computer, communicates on the network. Many newer IBMcompatible computers have built-in networking adapters, for Ethernet., , Because infrared signals are in the terahertz (higherfrequency) range, they have good throughout. Infrared, signals do have a downside: the signals cannot penetrate, Network adapters perform all the functions required to, walls or other objects and they are diluted by strong light, communicate on a network. They convert data from the, sources., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, 194, , Copyright @ NIMI Not to be Republished
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form stored in the computer to the form transmitted or, received (or transceived) on the cable and provide a, physical connection to the network., , How network adapters work : Network adapters receive, the data to be transmitted from the motherboard of your, computer into a small amount of RAM called a buffer., The data in the buffer is moved into a chip that calculates, a checksum value for the chunk and adds address, information, which includes the address of the destination, card and its own address, which indicates where the data, is from. Ethernet adapter addresses are permanently, assigned when the adapter is made at the factory. This, chunk is now referred to as a frame., For example, in Ethernet, the adapter listens for silence, on the network when no other adapters are transmitting., It then begins transmitting the frame one bit at a time,, starting with the address information, then the chunk of, data and then the checksum., , Fig 12 shows how an adapter plugs into a computer and, attaches to a network cable., , The network adapter must still convert the serial bits of, data to the appropriate media in use on the network. For, instance, if the data is being transmitted over optical, fiber, the bits are used to light up an infrared LED (light, emitting diode) or laser diode, which transmits light, pulses down the fiber to the receiving device’s APD, (avalanche photo diode) or photo-transistor. If the data is, being sent over twisted-pair cable, the adapter must, convert the bits of data from the 5-volt logic used in, computers to the differential logic used for digital twistedpair transmission., The circuitry used to perform this media conversion is, called a transceiver. Ethernet is the same no matter what, type of media you use only the transceiver changes., Transceivers can be external devices attached through, the AUI port on an Ethernet adapter, or they can be, internal on the card. Some cards (usually called combo, cards) have more than one type of transceiver built in so, you can use them with your choice of media. AUI, interfaces on Ethernet adapters are not transceiversthey are where you attach a transceiver for the different, media types., , Adapters in Abstract : Your computer software does not, have to be aware of how the network adapter performs its, function because the network driver software handles all, the specifics for your computer. The applications running, on your computer need only address data and hand it to, the adapter card., This is much the way the post office or a parcel delivery, service works. You don’t care about the details of postal, delivery; you simply address your parcel and hand it to, the delivery driver. The postal service manages the, process of delivering it for you., This abstraction allows your computer to use a microwave, radio transmitter just as earily as a fiber-optic network, adapter or an adapter that works over coaxial cable., , Because a network signal travels through copper and, optical fiber at about 66 percent as fast as the speed of, light, there’s a chance that one of two adapters far away, from each other could still be hearing silence when the, other has in fact started transmitting. In this case, they, could transmit simultaneously and garble their data. This, is referred to as a collision., While adapters transmit, they listen to the wire to make, sure the data on the line matches the data being transmitted. As long as it does, everything is fine. If another, adapter has interrupted, the data being, “heard” by the, transmitting network adapter will not match the data, being transmitted. If this happens, the adapter ceases, transmitting and transmits a solid on state instead, which, indicates to all computers that it has detected a collision, and that they should discard the current frame because, it has been corrupted. The network adapter waits a, random amount of time and then again attempts to, transmit the frame., , Everything in your computer remains the same except for, the actual network adapter and the driver software for that, adapter., IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished, , 195
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Configuring network adapters : Because network adapters have not been around since computers were invented,, there is no assigned place for cards to be set to. Most, adapter cards require their own interrupt, port address and, upper memory range. PCI motherboards automatically, assign IRQ and post settings to your PCI card, so you don’t, need to worry about it., Unfortunately, network adapters in computers with ISA, buses can conflict with other devices, since no two devices, , 196, , should share the same interrupt or port. No software that, comes with your computer will tell you every interrupt and, port in use unless your computer is already running, Windows NT, so you must be somewhat familiar with the, hardware in your computer or use a program that can probe, for free resources to find one. Many adapters have test, programs that can tell you whether the adapter is working, correctly with the settings you’ve assigned., , IT & ITES : COPA - (NSQF Level - 4) - Related Theory for Exercise 1.10.71 & 1.10.72, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73A, , Computer name and workgroup - Client server, Objectives : At the end of this lesson you shall be able to, • define computer name, • define workgroup, • explain client-server model, centralised computing and client computing with central file storage, • explain web server., Computer Name: In network computers are identified by, its IP Address, but a name can also be given to identify it, easily as remembering IP address is difficult comparing, remembering a alphanumeric name., Client-Server : The term Client-Server can describe, hardware, in which case it is referring to network servers, and client computers, or it can refer to a way of organising, software applications and services on a network. Clientserver computing is a powerful way of constructing, programs on a network. In order to describe its advantage, and how it works, we will first describe two alternatives to, client-server computing:, – Centralised computing, – Client computing with central file storage, Centralized computing : Centralized computing originated with mainframe computers and time-sharing. The, principle behind centralized computing is that a central, computer executes a program, such as a database or a, transaction-processing program (for instance, an airline, reservations system or a bank records program) and, remote terminals merely display data on a screen and, convey keyboard data back to the central computer., , Workgroup: In a network computers can be grouped, together by using workgroup feature. Computers in a, particular workgroup will show together when you open a, workgroup. Though a computer of one workgroup can, access other workgroup computers also., Client computers cooperate to ensure that central files, are not corrupted by attempts by several computers to, access them at the same time. When a client computer, needs to perform an operation, the file is transferred to, the client computer to perform the operation. Two, examples of this type of application are networked, database programs that do not use a SQL. (Structured, Query Language) server and any network-aware, application that does not communicate with a special, program executing on the server, such as network, scheduling programs and groupware., , In modern networks, personal computers can perform, the role of dumb terminals. With Windows software, the, PC can appear to the central computer as many terminals,, each virtual terminal accessing different data or, performing a separate transaction on the mainframe., In centralized computing it is the central computer that, does all the work. The data resides on the central, computer and the program executes on the central, computer. The personal computer or dumb terminal only, display screen data and accepts keystrokes for the, central computer to process. Centralized computing, does not fully use the capabilities of today’s powerful, network clients. Fig 1 illustrates centralized computing., Client computing with Central file storage : At the, opposite end of the spectrum from centralized computing, is client computing with central file storage (see Fig 2). In, this way of organizing an application, the client computer, does all the work. A central file server stores, but that is, all., , Copyright @ NIMI Not to be Republished, , 197
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One example of a front end is Microsoft Access when it, is used with a SQL back end. (You can also use Access, without a SQL back end.) Access displays tables in, windows or in forms you can browse. It allows you to, modify and search the tables in an easy-to-use graphical, environment. All the actual data manipulation, however,, occurs on the SQL server. Access translates all the database operations into SQL for the server to perform. The, results of the operations are transmitted back to Access, to display in an intuitive, graphical form., , While it is fully exploits the capabilities of client computers, and provides a richer and more customizable environment, for the user, this type of program can place heavy, demands on the network if the data files in which program, works with are large. It also takes time to transmit data, from the server to the client, process the data, and, transfer it back to the server so other network programs, can access the data., The Client-Server Model : The client-server model, combines the advantages of both the centralized, computing model and the client model of computing. It, does this by performing the operations that are best, executed by a central computer on the file server and, performing those operations that are best done close to, the user on the client computer (see Fig 3). The clientserver model works best when many people need access, to large amounts of data. Simply stated, a client-server, system is any system in which the client computer makes, a request over a network to a server computer that then, satisfies the request., The Client : When you use a client-server system, what, you see is the client, or front end. It presents the interface, to manipulate or search for data. The request you make, by manipulating windows, menu, check boxes and so on,, is translated into a compact form that the client transmits, over the network for the server to perform., , SQL is not limited to database programs such as Microsoft, Access. User programs such as Microsoft Excel can use, SQL to query the back-end data-base server for values, to use in spreadsheet calculations. Program tools allow, custom programs to store and retrieve data in serverbased databases. Query tools provide direct access to, the SQL data., The Server : The server is where data operations in a, client-server system occur. The central computer can, service many client requests quickly and efficiently,, which is the traditional advantage of centralized, computing. The central computer can also provide, enhanced security by performing only authorized, operations on the data., Back-end database software is optimized to perform, searches and sorts and the back-end computer is often, more powerful than the front-end computer., Web server : A web server is a program using the client/, server model and the World Wide Web’s Hyper Text, Transfer Protocol (HTTP) serves the files that form web, pages to web users., Every computer on the internet that contains a web site, must have a web server program. The most popular web, servers are: The Microsoft’s Internet Information Server, (IIS) which comes with the Microsoft’s Windows NT, Server; Netscape Fast Track and Enterprises Servers, and Apache, a web server for Unix-based operating, systems. Other web servers include Novell’s Web Server, for users of its Netware Operating System and IBM’s, family of Lotus Domino Servers. Primarily for IBM’s OS/, 390 and AS/400 customers., Web servers often come as a part of a larger package of, Internet related programs for serving e-mail, downloading, requests for File Transfer Protocol (FTP) files and building, and publishing web pages. Consideration in choosing a, web server include how well it works with the operating, system and other servers, its ability to handle server side, programming and publishing, search engine and site, building tools that may come with it., , 198, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished
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DHCP, Objectives : At the end of this lesson you shall be able to, • define DHCP, • explain DHCP., DHCP: Dynamic Host Control Protocol allows server, computers to distribute dynamic IP address when the, client establish connection to server. The server, maintains a IP address pool and it offer some IP which, is not already alloted to some other client. When client, disconnects from server its IP then becomes free again, and can be given to other client., , superseded by RFC 2131) that allows a server to, dynamically distribute IP addressing and configuration, information to clients. Normally the DHCP server, provides the client with at least this basic information:, , It is dynamic as same client can get different IP in, different times. It is beneficial as requirement of IP, address is less a all the clients are not always connected, to server and its saves the time to allocate IP to each, client manually., Dynamic Host Configuration Protocol (DHCP) is a, standard protocol defined by RFC 1541 (which is, , •, , IP Address, , •, , Subnet Mask, , •, , Default Gateway, , Other information can be provided as well, such as, Domain Name Service (DNS) server addresses and, Windows Internet Name Service (WINS) server, addresses. The system administrator configures the, DHCP server with the options that are parsed out to the, client., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73A, , Copyright @ NIMI Not to be Republished, , 199
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.73B, , Concept of proxy server, Objectives : At the end of this lesson you shall be able to, • explain the meaning of proxy server, • explain common connection point, • explain packet filtering, domain filtering and control user access by service, • explain logging and web publising., What is a proxy server? To be a “proxy” means to act on, behalf of another. This is exactly what a proxy server does;, it acts on behalf of its proxy clients to interact with other, servers. You could say that a proxy server is a “mediator”, for computer communications., Placing a proxy server on your network gives you several, advantages, including security enhancements, coaching, enhancements and greater control over your network, users. The advantages of using Microsoft Proxy Server, (MPS) is listed below:, – Common connection point, – Caching, – Packet filtering, – Domain filtering, – Control user access by service, – Logging, – Web publishing, Common connection point : MPS was designed to, connect two networks, rather like a gateway. Typically,, MPS connects an internal network and the Internet. This, configuration gives the internal computers a common, connection point to the Internet-through MPS., When used to provide a common connection, MPS lets, clients share a single connection to the Internet. Instead of, giving each user on a Local Area Network (LAN) a separate, modem, phone line and dial-up account to the Internet,, MPS can function as a gateway to the Internet using a, single connection. Instead of using separate standard, phone line connections, users can share a single higherspeed connection through the proxy server. The net effect, is usually an overall cost savings and reduction in administrative overhead. One connection is usually cheaper and, easier to maintain than several separate connections., Caching : Since you can use MPS as a common connection point to the Internet, you can also use it to cache, frequently accessed resources. MPS allocates a portion of, the server’s hard disk space to store frequently accessed, objects., Caching can either be passive or active. Passive caching, just stores objects as they are requested so the cache is, updated only when users request information. Active, caching directs the server to refresh objects in the cache, automatically., 200, , You can selectively control MPS caching so that you can, limit the size of cached objects, change the expiration, limits (control the freshness of objects) and determine, whether MPS always caches or always excludes from, cache certain content., Caching only works with the Web Proxy Service, in MPS. You will learn more about the Web Proxy, Service later in this chapter., Packet Filtering : To protect internal users from the, outside world (in other words to protect the network from, outsiders), MPS provides packet-filtering services. A packet, filter prevents unauthorized access from the outside by, limiting the available connection points coming into the, network. To that end, packet filters stop various types of, protocols from entering the network., MPS supports both static and dynamix packet filters. A, static filter keeps all traffic of a certain description or type, from passing through MPServer. A dynamic packet filter, automatically determines which type of traffic is allowed in, or out. With a static filter the administrator defines the port,, the protocol and may be the IP address. With a dynamic, filter the administrator just defines the service to be allowed, or filtered., Domain Filtering : MPS also lets you limit the access of, your internal clients to the Internet. You can configure, filters for a single computer, a group of computers or a, domain name. Many companies prefer to have this type of, control over their users because they can block access to, Internet sites that they believe reduce employee productivity or contain offensive material. Some popular examples, of domain filtering are blocking access to Internet game, servers or Web sites that contain pornographic material., You can configure domain filters for a specific IP address,, IP address and subnet mask or domain name. IP address, filters prevent users from contacting a single computer., Using the IP address and subnet mask as a filter limits, access to an entire group (a subnet) of computers. Domain, name filters can apply to an entire Web site or to subsections of that site., Control user access by Protocol or Service : You can, also selectively enable and disable ports, services and, protocols through MPS. MPS lets you control access to, Internet services at the user level. You can also enable or, restrict access to protocols on a user or group basis. Many, protocols are predefined in the default MPS configuration., , Copyright @ NIMI Not to be Republished
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If the protocol or service you would like to enable or disable, is not defined in the MPS property sheets, you can create, a new sheet. you can define a protocol by TCP (Transmission Control Protocol) or UDP (User Datagram Protocol), port number or range. This gives you the ability to control, access by port., Logging : Because all traffic between networks passes, through MPS, MPS has the unique opportunity to log and, track communication. You can track the information your, internal clients get from other networks or the Internet and, monitor inbound communication. You can use this information to help you secure your internal network from attack, and unauthorized access. Plus, you can monitor where, your users spend their time on the Internet and what, information they are downloading., Web publishing : MPS can also act as a Web server., MPS can service requests from cache on behalf of a Web, server, pass requests to the Web server on the local, system or pass requests to another Web server on the, internal network. The terms “reverse proxying” and “reverse, hosting” describe the Web Publishing services that MPS, provides., As a reverse proxy, MPS listens to incoming Web requests, for a single Web server on the local network. The incoming, requests are simply forwarded to another Web server. Web, hosting requires more work on the part of MPS. As a, reverse host, MPS can send requests to one of many Web, servers. In this case, MPS responds as if the entire site, were contained locally, even though the actual data may be, coming from several different Web servers., The main difference between reverse proxying and reverse, hosting is that in performing reverse proxying, MPS forwards all requests to the Web server. In performing reverse, hosting, MPS selectively forwards requests to multiple, Web servers on the internal network. In reverse hosting, the, Microsoft Proxy Server routes an external request for a, resource (that specifies an Internet domain name) to one, or more internal Web servers. For instance, requests for, http://www.hudlogic.com/bios might be routed to an internal server named “business” (http://business), while requests for http://www.hudlogic.com/pictures could be sent, to a different Web server named “server1” (http://server1)., Services : Microsoft Proxy Server 2.0 supports Hypertext, Transfer Protocol (HTTP) version 1.1, Windows Sockets, version 1.1, SOCKS version 4.3a and Secure Sockets, Layer (SSL) 3.0. The MPS services that provide this, support are the Web Proxy service, WinSock Proxy, service and the SOCKS Proxy service, respectively., , Web Proxy Service : The Web Proxy service provides, support for HTTP (a.k.a.Web publishing), FTP, Gopher and, secure (SSL) communications. The Web Proxy service, works with any CERN-compliant Web browser, such as, Internet Explorer or Netscape Navigator. Because the Web, Proxy supports only these widely adopted Internet standard communication methods, it isn’t operating system, dependent. Clients running Unix, Macintosh or Windows, operating systems can communicate with the Web Proxy, service as long as they’re configured with a CERN-complaint Web browser., Any operating system using a CERN-compliant, Web browser can communicate through the Web, Proxy server, regardless of its underlying operating system., WinSock Proxy Service : The WinSock Proxy service, supports Microsoft Windows operating systems using, Windows Sockets. This supprt is available for both Transmission Control Protocol/internet Protocol (TCP/IP) and, Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocols. The WinSock Proxy service, applies mainly to Windows clients including Windows 3.x,, windows 95 and Windows NT., Windows Sockets is an interprocess communication, mechanism derived from the Berkeley Sockets interface, (originally designed for Unix systems). The Sockets interface was extended to support Windows-based clients, running Microsoft implementations of TCP/IP. The name, given to this Sockets interface for Windows was WinSock, (for Windows Sockets)., The WinSock Proxy Service doesn’t support 16-bt, IPX/SPX clients such as the Windows 3.x 16-bit, Netware clients., SOCKS Proxy Service : The SOCKS Proxy service, supports SOCKS version 4.3a client applications such as, FTP, Gopher and Telnet. Operating systems like Macintosh and Unix can run SOCKS 4.3a and access the, SOCKS Proxy service when communicating through the, Microsoft Proxy Server. One limitation of the SOCKS proxy, service on MPS is that it does not support UDP-based, protocols., UDP-based protocols aren’t supported through, the SOCKS Proxy service, but the WinSock Proxy, service does support UDP for Windows clients., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.73B, , Copyright @ NIMI Not to be Republished, , 201
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.74, , Video conferencing, Objectives: At the end of this lesson you shall be able to, • define video conferencing, • list the advantages of video conferencing, • list the disadvantages of video conferencing., Video Conferencing, , and eye contact in these. Video conferencing allows, users to successfully convey, creating essential social bonds and shared understandings., , Definition: Videoconferencing is the conduct of a conference by a set of telecommunication technologies, which allow two or more remotely located teams to communicate by simultaneous two-way video and audio, transmissions. It has also been called 'visual collaboration' and is a type of groupware., , 5 Increased Productivity, , Video conferencing is a very useful technique to cut down, various costs as well as travel time when meetings and, conferences are concerned.Video conferencing connects, individuals in real time through audio and video communication over broadband networks. It enables visual, meetings and collaboration on digital documents and, shared presentations. New technologies allow participants to connect remotely over a network through multiple devices like laptops, desktops, smartphones and, tablets., , 7, , Advantages, 1 Significant Travel Savings, 2 Not only is video conferencing a direct replacement, for many in-person business trips, but because there, is virtually no cost to add additional key employees, to a virtual meeting, it is a cost effective solution., , 6 Important meetings are shorter and more effective., But it is a well-known fact that many meetings take, longer than the necessary time of the participants., Video conferencing users can save a minimum of, two hours a week with the technology. The interactivity, of group collaboration and document sharing greatly, increases productivity., Conferencing Quality, , 8 The present day state-of-the-art technology delivers, excellent, reliable audio and video quality, making, conferencing very effective and interesting too., Disadvantages, 1 Absence of Physical Presence, 2 Initial installation costs, 3 Not yet popular with a large size of users., , 3 Improved Communication, 4 Audio conferencing and e-mail may be used for communication but there is a lack of visual connection, , 202, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Networking Concepts, , Related Theory for Exercise 1.10.75, , Network security, Objectives: At the end of this lesson you shall be able to, • define network security, • explain network security concepts., Network security consists of the provisions and policies, adopted by a network administrator to prevent and, monitor unauthorizedaccess, misuse, modification, or, denial of a computer network and network-accessible, resources. Network security involves the authorization, of access to data in a network, which is controlled by the, network administrator., Network security concepts, Network security refers to any activities designed to, protect your network. Specifically, these activities protect, the usability, reliability, integrity, and safety of your, network and data. Effective network security targets a, variety of threats and stops them from entering or, spreading on your network., Network security starts with authenticating, commonly, with a username and a password. Since this requires, just one detail authenticating the user name -i.e. the, password- this is sometimes termed one-factor, authentication. With two-factor authentication, something, the user needs a 'dongle', an ATM card, or a mobile, phone, and with three-factor authentication, something, the user needs a fingerprint or retinal scan., Once authenticated, a firewall decides what services, are allowed to be accessed by the network users. Though, effective to prevent unauthorized access, this component, may fail to check potentially harmful content such as, computer worms or Trojans being transmitted over the, network., Anti-virus software or an intrusion prevention system, (IPS) helps detect and inhibit the action of such malware., Encrypting the communication between two hosts using, a network helps maintain privacy., Surveillance and early-warning toolssometimes referred, to as Honeypots can be employed., Hhoneypot is a trap set to detect, deflect, or, in some, manner, counteract attempts at unauthorized use of, information systems. Generally, a honeypot consists of, a computer, data, or a network site that appears to be, part of a network, but is actually isolated and monitored,, and which seems to contain information or a resource of, value to attackers. This is similar to the police baiting a, criminal and then conducting undercover surveillance., , The Foundations of Security, Security relies on the following elements:, •, , Authentication, , Authentication addresses the question: who are you? It is, the process of uniquely identifying the clients of your, applications and services. These might be end users,, other services, processes, or computers. In security, parlance, authenticated clients are referred to as, principals., •, , Authorization, , Authorization addresses the question: what can you do?, It is the process that governs the resources and, operations that the authenticated client is permitted to, access. Resources include files, databases, tables, rows,, and so on, together with system-level resources such as, registry keys and configuration data. Operations include, performing transactions such as purchasing a product,, transferring money from one account to another, or, increasing a customer's credit rating., •, , Auditing, , Effective auditing and logging is the key to nonrepudiation. Non-repudiation guarantees that a user, cannot deny performing an operation or initiating a, transaction. For example, in an e-commerce system,, non-repudiation mechanisms are required to make sure, that a consumer cannot deny ordering 100 copies of a, particular book., •, , Confidentiality, , Confidentiality, also referred to as privacy, is the process, of making sure that data remains private and confidential,, and that it cannot be viewed by unauthorized users or, eavesdroppers who monitor the flow of traffic across a, network. Encryption is frequently used to enforce, confidentiality. Access control lists (ACLs) are another, means of enforcing confidentiality., •, , Integrity, , Integrity is the guarantee that data is protected from, accidental or deliberate (malicious) modification. Like, privacy, integrity is a key concern, particularly for data, passed across networks. Integrity for data in transit is, typically provided by using hashing techniques and, message authentication codes., , Copyright @ NIMI Not to be Republished, , 203
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•, , Availability, , How Do You Build a Secure Web Application?, , From a security perspective, availability means that, systems remain available for legitimate users. The goal, for many attackers with denial of service attacks is to, crash an application or to make sure that it is sufficiently, overwhelmed so that other users cannot access the, application.Threats, Vulnerabilities, and Attacks Defined, A threat is any potential occurrence, malicious or, otherwise, that could harm an asset. In other words, a, threat is any bad thing that can happen to your assets., A vulnerability is a weakness that makes a threat, possible. This may be because of poor design,, configuration mistakes, or inappropriate and insecure, coding techniques. Weak input validation is an example, of an application layer vulnerability, which can result in, input attacks., , It is not possible to design and build a secure Web, application until you know your threats. An increasingly, important knowledge needed is about threat modeling., The purpose of threat modeling is to analyze your, application's architecture and design and identify, potentially vulnerable areas that may allow a user,, perhaps mistakenly, or an attacker with malicious intent,, to compromise your system's security., After you know your threats, design with security in mind, by applying proven security principles. You must follow, secure coding techniques to develop secure, robust, and, hack-resilient solutions. The design and development of, application layer software must be supported by a secure, network, host, and application configuration on the, servers where the application software is to be deployed., , An attack is an action that exploits a vulnerability or, enacts a threat. Examples of attacks include sending, malicious input to an application or flooding a network in, an attempt to deny service., , 204, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.10.75, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.76 & 1.11.77, , E-mail, Objectives : At the end of this lesson you shall be able to, • state the hotmail services offered, • explain MSN outlook express and its tools, • explain popular search engines, • state the FAQs about hotmail., Hotmail: MSN Hotmail is the world’s largest provider of, free Web-based e-mail. Hotmail is based on the premise, that e-mail access should be easy and possible from any, computer connected to the World Wide Web., By adhering to the universal HyperText Transfer Protocol, (HTTP) standard, Hotmail eliminates the disparities that, exist between different e-mail programs. Sending and, receiving e-mail from Hotmail is as easy as going to the, Hotmail web site at http://www.hotmail.com, or by clicking, on the Hotmail link at http://www.msn.com, signing in,, and sending an e-mail message., Hotmail is the web-based e-mail provider, which means, you can send and receive messages from any computer, connected to the Internet. You can use Hotmail from, home, work, school, an Internet cafe, a friend’s house or, any other computer in the world with an Internet connection. Your messages are stored in a central location, so, your Inbox will always be up to date. This is great for, people who use more than one computer, travel frequently, or don’t even own a computer., Advantages of Hotmail, Get a permanent e-mail address: When you create a, Hotmail account, you choose a permanent e-mail address that will never change as long as you continue to, use Hotmail. This is great for people who: Want to switch, Internet Service Providers. Your Hotmail address will be, the same no matter how you access the Internet, so you, don’t have to worry about retrieving messages from your, old address or notifying friends, family and associates of, a new e-mail address. You are free to select any Internet, Service Provider that suits your needs., When you leave town for travel, you may no longer have, access to your ISP’s e-mail account. But with Hotmail,, your friends will always know where to reach you., Your e-mail is private and secure: When you sign up, for Hotmail, you choose your personal ID and password., The only way you can access your account is by using the, password you selected. This means that only you will, have access to your Hotmail account, even if you use a, computer at a public terminal or a friend’s house. Because, the messages in your Hotmail account are stored securely at a central location, you don’t have to worry about, losing important information if something happens to, your computer. Hotmail is strongly committed to keeping, your personal information confidential., , Hotmail is fast and easy to use: Hotmail is recognized, world wide as the best Web-based e-mail service. It is, also stated that ‘while others provide similar services,, none can match Hotmail’s general ease of use’. If everything is fine, it takes less than a minute to get started on, Hotmail and its pages are so worked out to load quickly, knowing that the users time is valuable., Get an additional e-mail account for FREE:Hotmail, offers everyone the opportunity to get a free e-mail, account. Hotmail can offer e-mail accounts for free, because it places banner advertising on some of its, pages. Some Internet Service Providers charge a monthly, fee for additional e-mail accounts. Hotmail lets an, unlimited number of people use a single Internet Service, Provider account and have a free, personal e-mail, account., Keep your personal e-mail separate from your work, e-mail: People who use e-mail for work will find it, convenient to keep their personal messages separate, from their work messages. You can use Hotmail for your, personal correspondence and your company’s e-mail, system only for business messages. Additionally, you, don’t have to store personal e-mail on your company’s, servers. All messages in your Hotmail account are, securely stored in a central location that you access via, the Internet with the password you select., Outlook Express, Microsoft Outlook Express puts the world of online, communication on your desktop. Whether you want to, exchange e-mail with colleagues and friends or join, newsgroups to trade ideas and information. Some of the, tools offered by outlook express are;, Manage multiple mail and news accounts: If you have, several mail or news accounts, you can use them all from, one window. You can also create multiple users, or, identities, for the same computer. Each identity gets its, own mail folders and Address Book. The ability to create, multiple accounts and identities makes it easy for you to, keep work separate from personal mail and also between, individual users., Browse through messages quickly & easily: Using, the message list and preview pane, you can view a list of, messages and read individual messages at the same, time. The Folders list contains mail folders, news servers,, and newsgroups, and you can easily switch between, them. You can also create new folders to organize and, sort messages, and then set up message rules so that, , Copyright @ NIMI Not to be Republished, , 205
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incoming mail that meets your criteria automatically, goes to a specific folder. You can also create your own, views to customize the way you look at your mail., Keep your mail on a server so you can view it from, more than one computer: If your ISP uses an IMAP, mail server for incoming mail, you can read, store, and, organize your messages in folders on the server without, downloading the messages to your computer. That way,, you can view messages from any computer that can, connect to that server., Use the Address Book to store and retrieve e-mail, addresses: You can save names and addresses in your, Address Book automatically by simply replying to a, message or by importing them from other programs, by, typing them in, by adding them from e-mail messages, you receive, or by searching popular Internet directory, services (white pages). The Address Book supports, Lightweight Directory Access Protocol (LDAP) for, accessing Internet directory services., Add a personal signature or stationery to your messages: You can insert essential information into outgoing messages as part of your personal signature, and you, can create multiple signatures to use for different, purposes. For more detailed information, you can include, a business card. To make your messages look more, attractive, you can add stationery patterns and backgrounds, and you can change the color and style of the, text., Send and receive secure messages: You can digitally, sign and encrypt messages by using digital IDs. Digitally, signing your message assures recipients that the message is really from you. Encryption ensures that only, intended recipients can read a message., Find newsgroups that interest you: Looking for a, newsgroup that matches your interests? You can search, for newsgroups that contain keywords or browse through, all of the newsgroups available from your Usenet provider. When you find a newsgroup you want to view, regularly, add it to your Subscribed list so you can find it, again easily., View newsgroup conversations efficiently: You can, view a newsgroup message and all of the responses, without reading an entire message list. When you view, the list of messages, you can expand and collapse, conversations to make it easier to find what interests you., You can also use views to display only the messages you, want to read., Download newsgroup messages for offline reading:, To use your online time efficiently, you can download, messages or entire newsgroups, so you don’t have to be, connected to your ISP to read messages. You can also, download message headers only for offline viewing and, then mark the headers of the messages you want to read;, then the next time you are connected, Outlook Express, downloads the message text. You can also compose, messages offline and send them the next time you, reconnect., 206, , Some important (Top 8 ) recommendations for staying, safe and secure when you’re online are listed below;, – Change your password often. The quick act of changing your password can ensure your e-mail remains, private. In addition,passwords that use both letters, and numbers are harder to break., – Don’t share your password. Most e-mail administrators will not ask for your password. Do not be duped, by malicious e-mails asking you for your password., This is a well-known, although not-too-common trick, designed to fool you into sharing your password. As, a rule, never share it with anyone., – Never open attachments from unknown sources., They may contain what are known as “letterbombs” or, “viruses,” which can damage your PC., – Always remember to sign out when you are done. It’s, quick, easy and may save your account from unwanted trespassers. If you are using a public terminal,, at an internet cafe for example, it is advised that you, close the browser you were using when you are ready, to end your Internet session., – Don’t reply to unsolicited messages (“spam”) mail, or, other harassing or offensive mail. By responding, you, only confirm that you are a person with an active email address who can be plagued with constant, unwanted e-mail solicitations. Instead, forward the, unsolicited message to the customer service, department of the source’s e-mail (usually of a form, similar to, abuse@[implicateddomain].com). To, help control spam, Hotmail provides members with, “filters” for incoming mail. These can easily be set up, to send certain messages (such as those that include, certain words) directly to your online trash can., – Make sure that you are using the most up-to-date, Internet software (e.g. browsers such as Microsoft, Internet Explorer or Netscape Navigator). More recent, versions often offer enhanced security protection., – Always use a secure network. Most corporate networks and Internet service providers are protected by, administrators who watch for potential security problems and act to protect users from “hackers” (malicious users) who may try to steal personal information, that is transferred through the network. Although the, risk is small, use caution when on any unfamiliar, network., – Use stations maintained by sources you trust, or ask, if the Internet terminal you are using is protected, against security break-ins., A SMALL LIST OF Search Engines, Yahoo.com (http://www.Yahoo.com), Search.com (http://search.com), EasySearcher (http://www.easysearcher.com), AltaVista (http://www.altavista.com), Excite (http://www.excite.com), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
Page 976 : Google (http://www.google.com), Hotbot (http://www.hotbot.com), Infoseek (http://www.infoseek.com), Lycos (http://www.lycos.com), WebCrawler (http://www.webcrawler.com), www.all4one.com (This useful tool queries four search, engines at once), , Also, MSN has introduced Preview 2 of MSN Explorer as, an integrated client for MSN services, such as MSN, Hotmail. This client allows you to also store Hotmail, locally on your machine. This too reduces the amount of, storage that you need on hotmail., 2 Can I get Hotmail in different languages?, MSN Hotmail can now be viewed in a variety of languages., , www.askjeeves.com (Insted of entering words to search, for, just type in your question), , You can make the language of a Hotmail session match, the language of the Sign In page used to begin that, session. You have your choice of the following languages: English, French, German, Italian, Japanese,, Portuguese (Brazilian), and Spanish, and more to come., , www.rediff.com (Search for anything), , 3 Can I use Hotmail as a business address?, , www.bigfoot.com (Looking for someone’s email address ? Try here), www.hotbot.com (Useful search engine which helps to, find pictures, video or music), , No. You may not use your Hotmail address as your, primary business address. If, however, you work for a, company with which you have an e-mail address and you, want to use your Hotmail account to send and receive email while away from your computer at work, you are, encouraged to do so., , www.indiainfo.com (Info lets you search the web easily), , Example of Prohibited Use:, , www.yahoo.com (Search engine which is also the most, popular), , You are an individual who runs a business. You and your, employees want to use Hotmail accounts rather than, registering and administering your account through a, paid ISP., , www.av.com (Very powerful search engine which gives, plenty of results), , www.sawaal.com (All your questions answered), , mp3.lycos.com (The place to start if you’re after music, files in the mp3 format), www.metacrawler.com (Metacrawler puts your search, through a host different engines), www.mirago.co.uk (A search engine eith an excellent, selection of shopping links), www.webferret.com (One of the easiest way to search, the web), www.indiatimes.com (The portal’s search engine), www.webcrawler.com (Let the webcrawler spider to do, the searching for you), www.indonet.net (Excellent Indian search engine with, loads of useful search catagories), www.satyamonline.com (On ISP’s site and has good, search options), COMPILED LIST OF INTERESTING FAQ’s about, HOTMAIL, 1 How much e-mail storage space do I get with Hotmail?, Hotmail offers 2MB of storage space. If you do not keep, your account below this limit, Hotmail may remove some, messages, which cannot be recovered., If you need additional storage space, there are a few, options. You can use the latest version of Microsoft, Internet Explorer v5 or above, which includes Outlook, Express, which offers you the ability to store e-mails, locally. You can send a blank e-mail message to,
[email protected] for more information on how to, use the beta (pre-release) process to store Hotmail, messages on your local PC, using Outlook Express., , Example of Allowed Use:, You are a businessperson who travels. You have an, account with your company (yourname@your, company.com). You use your Hotmail account to read, and send solicited messages while you are traveling., Hotmail prohibits account sharing. Since Hotmail is, accessible from everywhere in the world, each individual, is able to sign up for his or her own personal account. You, are encouraged to sign up for an account of your own, to, which only you have access. Sharing an account compromises the privacy and security of your e-mail. Each, Hotmail user must have his or her individual e-mail, account., 4 Is my e-mail really private and secure? (SSL)?, Secure connections (often called SSL, or Secure Sockets Layer) is the industry standard in Web security. It is, used primarily for transmitting sensitive information over, the Internet. When you have a secure connection between, your, browser and a Web site, no one else can easily, access the data that you send across the connection., Hotmail uses SSL to encrypt your sign-in name, and, password, when you log in to give you a high level of, security., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished, , 207
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It is Hotmail’s policy to respect the privacy of its users., Therefore, Hotmail will not monitor, edit, or disclose the, contents of a user’s private communications unless, required to do so by law or in the good faith belief that, such action is necessary to:, – conform to the edicts of the law or comply with, legal process served on Hotmail;, – protect and defend the rights or property of, Hotmail; or, – act under exigent circumstances to protect the, personal safety of its users or the public., 5 Can Hotmail protect its users from e-mail viruses?, MSN Hotmail is pleased to offer users McAfee VirusScan, for free. Whenever you receive attachments in your, Hotmail account, it will automatically scan them with, McAfee’s popular VirusScan before downloading., MSN Hotmail recently added the ability to have all, attachments you want to send scanned before they can, be attached to your outgoing e-mail. So before you, upload file to send to another user, it will also be scanned, for viruses before you send it, reducing the spread of, viruses to Hotmail users and the other recipients of your, e-mail., Remember, to ensure safety, Hotmail recommends that, you never open attachments from unknown sources., , You can also accent your messages by using Rich Text, Formatting. The Rich Text Formatting option, also allows, you to add emoticons to your e-mail. This new feature, allows you to add selected symbols or emoticons to your, message. These icons help you convey emotion or add, flair within a message., 7 What does it mean when my account is marked, “inactive”?, Currently, if you do not sign in to your Hotmail account for, 60 days, or if you do not sign-in within the first 10 days,, your account will be marked “inactive.” Stored e-mail and, addresses will be deleted, and inbound mail will be, refused. Your Passport will still function, and your Hotmail, e-mail name will be reserved. To re-activate your account,, simply go to http://www.hotmail.com and enter your, Sign-In name and password. You will then be able to, once again send and receive e-mail using hotmail. If your, account stays “inactive” for over a period of 90 days, it, may be permanently deleted., 8 Can I send and receive attachments on Hotmail?, Yes, you can send and receive as many files as you want, to a message - up to 1MB (1024K) of attachments., Attachments sent to your Hotmail account can be, downloaded to your personal computer by clicking them., GIF and JPEG images and HTML files are automatically, displayed in the browser window., , 6 How do I send images and use e-mail stationery to, make e-mail I send more colorful and fun?, (Emoticons/Stationery/RTF), MSN Hotmail offers users stationery to send fun, colorful, messages to family and friends! Always capture the right, mood for your messages by selecting one of the many, different stationery templates. Use the Stationery Chooser, button on the Compose page to view the available, stationery choices., , 208, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.76 & 1.11.77, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.78, , Chatting, video chatting and using social network sites, Objectives : At the end of this lesson you shall be able to, • explain chating process, • explain video chating process, • explain social network services., Chatting Process, A web chat is a system that allows users to communicate, in real time using easily accessible web interfaces. It is, a type of internet online chat distinguished by its simplicity, and accessibility to users who do not wish to take the, time to install and learn to use specialized chat software., This trait allows users instantaneous access and only a, web browser is required to chat. Users will always get, the latest version of a chat service because no software, installation or updates are required., Video Chat, In video chat video of both caller and receiver can be, seen on screen of both user along with audio. So it gives, an impression of face to face interaction though the caller, and receiver can be thousands of mile apart., Social Networking services, A social networking service is a platform to build social, networks or social relations among people who, share, interests, activities, backgrounds or real-life connections., A social network service consists of a representation of, each user (often a profile), his social links, and a variety, of additional services. Social networking is web-based, services that allow individuals to create a public profile,, to create a list of users with whom to share connection,, and view and cross the connections within the system., Most social network services are web-based and provide, means for users to interact over the Internet, such as email and instant messaging.Social network sites are, varied and they incorporate new information and, communication tools such as, mobile connectivity, photo/, video/sharing and blogging. Online community services, , are sometimes considered as a social network service,, though in a broader sense, social network service usually, means an individual-centered service whereas online, community services are group-centered. Social, networking sites allow users to share ideas, pictures,, posts, activities, events, interests with people in their, network., The main types of social networking services are those, that contain category places (such as former school year, or classmates), means to connect with friends (usually, with self-description pages), and a recommendation, system linked to trust. Popular methods now combine, many of these, with American-based services such as, Facebook, Google+,YouTube, LinkedIn, Instagram,, Pinterest, Tumblr and Twitter widely used worldwide;, Nexopia in Canada; Badoo, Bebo, Vkontakte (Russia),, Delphi (also called Delphi Forums), Draugiem.lv (mostly, in Latvia), Hi5 (Europe), Hyves (mostly in The, Netherlands), iWiW (mostly in Hungary), Nasza-Klasa,, Soup (mostly in Poland), Glocals in Switzerland,Skyrock,, The Sphere, StudiVZ (mostly in Germany), Tagged,, Tuenti (mostly in Spain), and XING in parts of Europe;, Hi5 and Orkut in South America and Central America;, Mxit in Africa; and Cyworld, Mixi, Orkut, renren, weibo, and Wretch in Asia and the Pacific Islands., There have been attempts to standardize these services, to avoid the need to duplicate entries of friends and, interests (see the FOAF standard and the Open Source, Initiative). According to experts, the largest social, networking users are Asian-Pacific regions with 615,9, million people. A 2013 survey found that 73% U.S adults, use social networking sites., , Copyright @ NIMI Not to be Republished, , 209
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.79, , Explaining threats to computers connected to Internet & process of protecting computers from it., Objectives : At the end of this lesson you shall be able to, • explain threats to computers connected to Internet, • process of Protecting computers from Internet., A web threat is any threat that uses the World Wide Web, to facilitate cybercrime. Web threats use multiple types, of malware and fraud, all of which utilize HTTP or HTTPS, protocols, but may also employ other protocols and components, such as links in email or IM, or malware attachments or on servers that access the Web. They benefit, cybercriminals by stealing information for subsequent, sale and help absorb infected PCs into botnets., Web threats pose a broad range of risks, including financial damages, identity theft, loss of confidential information/data, theft of network resources, damaged, brand/personal reputation, and erosion of consumer confidence in e-commerce and online banking., It is a type of threat related to information technology, (IT). The IT risk, i.e. risk affecting has gained and increasing impact on society due to the spread of IT processes., Web threats can be divided into two primary categories,, based on delivery method - push and pull. Push-based, threats use spam, phishing, or other fraudulent means, to lure a user to a malicious (often spoofed) website which, then collects information and/or injects malware. Push, attacks use phishing, DNS poisoning (or pharming), and, other means to appear to originate from a trusted source., Precisely-targeted push-based web threats are often referred to as spear phishing to reflect the focus of their, data gathering attack. Spear phishing typically targets, specific individuals and groups for financial gain. In other, push-based web threats, malware authors use social engineering such as enticing subject lines that reference, holidays, popular personalities, sports, pornography,, world events and other hot topics to persuade recipients, to open the email and follow links to malicious websites, or open attachments with malware that accesses the, Web., Pull-based web threats are often referred to as "driveby" threats by experts (and more commonly as "driveby downloads" by journalists and the general public),, since they can affect any website visitor. Cybercriminals, infect legitimate websites, which unknowingly transmit, malware to visitors or alter search results to take users, to malicious websites. Upon loading the page, the user's, browser passively runs a malware downloader in a hidden HTML frame (IFRAME) without any user interaction., , 210, , Internet security, Internet security is a tree branch of computer security, specifically related to the Internet, often involving browser, security but also network security on a more general level, as it applies to other applications or operating systems, on a whole. Its objective is to establish rules and measures to use against attacks over the Internet. The, Internet represents an insecure channel for exchanging, information leading to a high risk of intrusion or fraud,, such as phishing. Different methods have been used to, protect the transfer of data, including encryption., Types of security, Network layer security, TCP/IP which stands for Transmission Control Protocol, (TCP) and Internet Protocol (IP) aka Internet protocol, suite can be made secure with the help of cryptographic, methods and protocols. These protocols include Secure, Sockets Layer (SSL), succeeded by Transport Layer, Security (TLS) for web traffic, Pretty Good Privacy (PGP), for email, and IPsec for the network layer security., Internet Protocol Security (IPsec), This protocol is designed to protect communication in a, secure manner using TCP/IP aka Internet protocol suite., It is a set of security extensions developed by the Internet, Task force IETF, and it provides security and authentication at the IP layer by transforming data using encryption. Two main types of transformation that form the basis, of IPsec: the Authentication Header (AH) and ESP. These, two protocols provide data integrity, data origin authentication, and anti-replay service. These protocols can be, used alone or in combination to provide the desired set, of security services for the Internet Protocol (IP) layer., The basic components of the IPsec security architecture are described in terms of the following functionalities:, •, , Security protocols for AH and ESP, , •, , Security association for policy management and traffic processing, , •, , Manual and automatic key management for the, internet key exchange (IKE), , •, , Algorithms for authentication and encryption, , Copyright @ NIMI Not to be Republished
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The set of security services provided at the IP layer, includes access control, data origin integrity, protection, against replays, and confidentiality. The algorithm allows, these sets to work independently without affecting other, parts of the implementation. The IPsec implementation, is operated in a host or security gateway environment, giving protection to IP traffic., Security token, Some online sites offer customers the ability to use a, six-digit code which randomly changes every 30-60, seconds on a security token. The keys on the security, token have built in mathematical computations and, manipulate numbers based on the current time built into, the device. This means that every thirty seconds there, is only a certain array of numbers possible which would, be correct to validate access to the online account. The, website that the user is logging into would be made aware, of that devices' serial number and would know the, computation and correct time built into the device to verify, that the number given is indeed one of the handful of, six-digit numbers that works in that given 30-60 second, cycle. After 30-60 seconds the device will present a new, random six-digit number which can log into the website., Electronic mail security (E-mail), Background, Email messages are composed, delivered, and stored, in a multiple step process, which starts with the message's, composition. When the user finishes composing the, message and sends it, the message is transformed into, a standard format: an RFC 2822 formatted message., Afterwards, the message can be transmitted. Using a, network connection, the mail client, referred to as a mail, user agent (MUA), connects to a mail transfer agent, (MTA) operating on the mail server. The mail client then, provides the sender's identity to the server. Next, using, the mail server commands, the client sends the recipient, list to the mail server. The client then supplies the, message. Once the mail server receives and processes, the message, several events occur: recipient server, identification, connection establishment, and message, transmission. Using Domain Name System (DNS), services, the sender's mail server determines the mail, server(s) for the recipient(s). Then, the server opens up, a connection(s) to the recipient mail server(s) and sends, the message employing a process similar to that used, by the originating client, delivering the message to the, recipient(s)., Pretty Good Privacy (PGP), Pretty Good Privacy provides confidentiality by, encrypting messages to be transmitted or data files to, be stored using an encryption algorithm such Triple DES, or CAST-128. Email messages can be protected by using, cryptography in various ways, such as the following:, •, , Signing an email message to ensure its integrity and, confirm the identity of its sender., , •, , Encrypting the body of an email message to ensure, its confidentiality., , •, , Encrypting the communications between mail servers, to protect the confidentiality of both message body, and message header., , The first two methods, message signing and message, body encryption, are often used together; however,, encrypting the transmissions between mail servers is, typically used only when two organizations want to protect, emails regularly sent between each other. For example,, the organizations could establish a virtual private network, (VPN) to encrypt the communications between their mail, servers over the Internet. Unlike methods that can only, encrypt a message body, a VPN can encrypt entire, messages, including email header information such as, senders, recipients, and subjects. In some cases,, organizations may need to protect header information., However, a VPN solution alone cannot provide a, message signing mechanism, nor can it provide, protection for email messages along the entire route from, sender to recipient., Multipurpose Internet Mail Extensions (MIME), MIME transforms non-ASCII data at the sender's site to, Network Virtual Terminal (NVT) ASCII data and delivers, it to client's Simple Mail Transfer Protocol (SMTP) to be, sent through the Internet. The server SMTP at the, receiver's side receives the NVT ASCII data and delivers, it to MIME to be transformed back to the original nonASCII data., Message Authentication Code, A Message authentication code (MAC) is a cryptography, method that uses a secret key to encrypt a message., This method outputs a MAC value that can be decrypted, by the receiver, using the same secret key used by the, sender. The Message Authentication Code protects both, a message's data integrity as well as its authenticity., Firewalls, A firewall (computing) controls access between networks., It generally consists of gateways and filters which vary, from one firewall to another. Firewalls also screen, network traffic and are able to block traffic that is, dangerous. Firewalls act as the intermediate server, between SMTP and Hypertext Transfer Protocol (HTTP), connections., Role of firewalls in web security, Firewalls impose restrictions on incoming and outgoing, Network packets to and from private networks. Incoming, or outgoing traffic must pass through the firewall; only, authorized traffic is allowed to pass through it. Firewalls, create checkpoints between an internal private network, and the public Internet, also known as choke, points(borrowed from the identical military term of a, combat limiting geographical feature). Firewalls can, create choke points based on IP source and TCP port, number. They can also serve as the platform for IPsec., Using tunnel mode capability, firewall can be used to, implement VPNs. Firewalls can also limit network, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.04, , Copyright @ NIMI Not to be Republished, , 211
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exposure by hiding the internal network system and, information from the public Internet. Also, WE HAVE A, LOT OF BIG WAYE to deal with it., Types of firewalls, Packet filter, , Ransomware and Scareware, Botnet, A botnet is a network of zombie computers that have, been taken over by a robot or bot that performs largescale malicious acts for the creator of the botnet., , A packet filter is a first generation firewall that processes, network traffic on a packet-by-packet basis. Its main job, is to filter traffic from a remote IP host, so a router is, needed to connect the internal network to the Internet., The router is known as a screening router, which screens, packets leaving and entering the network., , Spyware, , Stateful packet inspection, , A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to, make a computer resource unavailable to its intended, users. Although the means to carry out, motives for, and, targets of a DoS attack may vary, it generally consists of, the concerted efforts to prevent an Internet site or service from functioning efficiently or at all, temporarily or, indefinitely., , In a stateful firewall the circuit-level gateway is a proxy, server that operates at the network level of an Open, Systems Interconnection (OSI) model and statically defines what traffic will be allowed. Circuit proxies will forward Network packets (formatted unit of data ) containing a given port number, if the port is permitted by the, algorithm. The main advantage of a proxy server is its, ability to provide Network Address Translation (NAT),, which can hide the user's IP address from the Internet,, effectively protecting all internal information from the, Internet., Application-level gateway, An application-level firewall is a third generation firewall, where a proxy server operates at the very top of the OSI, model, the IP suite application level. A network packet is, forwarded only if a connection is established using a, known protocol. Application-level gateways are notable, for analyzing entire messages rather than individual, packets of data when the data are being sent or received., Malicious software, Malware, A computer user can be tricked or forced into downloading software onto a computer that is of malicious intent., Such programs are known as malware and come in many, forms, such as viruses, Trojan horses, spyware, and, worms. Malicious software is sometimes used to form, botnets., Viruses, Computer Viruses are programs that can replicate their, structures or effects by infecting other files or structures, on a computer. The common use of a virus is to take, over a computer to steal data., Worms, Computer worms are programs that can replicate themselves throughout a computer network, performing malicious tasks throughout., Trojan horse, A Trojan horse commonly known as a Trojan is a general term for malicious software that pretends to be harmless, so that a user willingly allows it to be downloaded, onto the computer., 212, , The term spyware refers to programs that surreptitiously, monitor activity on a computer system and report that, information to others without the user's consent., Denial-of-service attack, , Browser choice, Web browser statistics tend to affect the amount a Web, browser is exploited. For example, Internet Explorer 6,, which used to own a majority of the Web browser market share, is considered extremely insecure because vulnerabilities were exploited due to its former popularity., Since browser choice is more evenly distributed (Internet, Explorer at 28.5%,Firefox at 18.4%, Google Chrome at, 40.8%, and so on) and vulnerabilities are exploited in, many different browsers., Application vulnerabilities, Applications used to access Internet resources may contain security vulnerabilities such as memory safety bugs, or flawed authentication checks. The most severe of, these bugs can give network attackers full control over, the computer. Most security applications and suites are, incapable of adequate defense against these kinds of, attacks., Internet security products, Antivirus, Antivirus programs and Internet security programs can, protect a programmable device from malware by detecting and eliminating viruses; Before 2000 a user would, pay for antivirus software, 10 years later however, computer users can choose from a host of free security applications on the Internet., Security Suites, So called "security suites" were first offered for sale in, 2003 (McAffee) and contain a suite of firewalls, anti-virus, anti-spyware and more.They may now offer theft, protection, portable storage device safety check, private, internet browsing, cloud anti-spam, a file shredder or, make security-related decisions (answering popup windows) and several were free of charge as of at least, 2012., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.11.79, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Internet concepts, , Related Theory for Exercise 1.11.80 & 1.11.81, , Outlook Express & Google+, Objectives : At the end of this lesson you shall be able to, • explain outlook express, • explain Google+, Microsoft Outlook, , Creation, , Microsoft Outlook is a personal information manager from, Microsoft, available as a part of the Microsoft, Officesuite.Although often used mainly as an email, application, it also includes a calendar, task manager,, contact manager,note taking, journal, and web browsing.It, can be used as a stand-alone application, or can work, with Microsoft Exchange Server and Microsoft, SharePoint Server for multiple users in an organization,, such as shared mailboxes and calendars, Exchange, public folders, SharePoint lists, and meeting schedules., There are third-party add-on applications that integrate, Outlook with devices such as BlackBerry mobile phones, and with other software such as Office and Skypeinternet, communication. Developers can also create their own, custom software that works with Outlook and Office, components using Microsoft Visual Studio. In addition,, Windows Mobile devices can synchronize almost all, Outlook data to Outlook Mobile., , Google launched the Google+ service as an invitationonly "field test" on June 28, 2011, but soon suspended, early invites due to an "insane demand" for new accounts., On August 6, each Google+ member had 150 invitations to give outuntil September 20, 2011, when Google+, opened to everyone 18 years of age or older without the, need for an invitation. It was opened for a younger age, group (13 years or older in US and most countries, 14 or, older in South Korea and Spain, 16 or older in the Netherlands) on January 26, 2012. Google+ is available as a, website and on mobile devices., , Google+, Google+ (pronounced and sometimes written as Google, Plus) is a social networking and identity service that is, owned and operated by Google Inc. Google has described Google+ as a "social layer" that enhances many, of its online properties, and that it is not simply a social, networking website, but also an authorship tool that associates web-content directly with its owner/author. It is, the second-largest social networking site in the world, after Facebook. 540 million monthly active users are, part of the Identity service site, by interacting socially with, Google+'s enhanced properties, like Gmail, +1 button, and, YouTube comments. In October 2013, Google counted, 540 million active users who used at least one Google+, service, of which 300 million users are active in "the, stream"., , Before the launch, Google referred to Google+ as Google, Circles, a name alluding to its emphasis on organising, friendship information. Google+ is considered the, company's fourth foray into social networking, following, Google Buzz (launched 2010, retired in 2011), Google, Friend Connect (launched 2008, retired by March 1,, 2012) and Orkut (launched in 2004, as of 2013 operated, entirely by subsidiary Google Brazil). Sources such as, The New York Times have declared it Google's biggest, attempt to rival the social network Facebook, which has, over 1 billion users., , Copyright @ NIMI Not to be Republished, , 213
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IT & ITES, Related Theory for Exercise 1.12.82 to 1.12.92, COPA - Designing Static WebPages, Web designing, Objectives : At the end of this lesson you shall be able to, • explain web sites and web pages, • explain static and dynamic web pages, • explain HTML, DHTML and XML, • explain the concept of web hosting, web server, application server and database server., Introduction, The World Wide Web (WWW) was created in 1990 by, CERN physicist Tim Berners-Lee. On 30 April 1993,, CERN announced that the World Wide Web would be, free to use for anyone. Before the introduction of HTML, and HTTP, other protocols such as File Transfer Protocol, and the Gopher Protocol were used to retrieve individual, files from a server. These protocols offer a simple directory, structure which the user navigates and chooses files to, download. Documents were most often presented as plain, text files without formatting, or were encoded in word, processors formats., Websites, A website, also written as Web site, web site, or simply, site, is a set of related web page containing content, (media) such as written language, Image, video, sound,, etc. A website is hosted on at least one web server,, accessible via a network such as the internet or a private, local area network through an Internet address known, as a uniform resource locator. All publicly accessible, websites collectively constitute the world wide web., A webpage is a document, typically written in plain text, interspersed with formatting instructions of Hypertext, Mark-up Language (HTML) XHTML. A webpage may, incorporate elements from other websites with suitable, HTML anchor., Web pages are accessed and transported with the, Hypertext Transfer Protocol (HTTP), which may optionally, employ encryption secure, HTTPS to provide security and, privacy for the user of the webpage content. The user's, application, often a web browser, renders the page content, according to its HTML Mark-up instructions onto a, Computer monitor., The pages of a website can usually be accessed from a, simple Uniform Resource Locator (URL) called the web, address. The URLs of the pages organize them into a, hierarchy, although hyperlink between them conveys the, reader's perceived sitemap and guides the reader's, navigation of the site which generally includes a Home, page with most of the links to the site's web content, and, a supplementary about page, contact page and link page., , 214, , Some websites require a subscription to access some or, all of their content. Examples of subscription websites, include many business sites, parts of news websites,, Academic journal websites, gaming websites, file-sharing, websites, Internet forum, web-based Email, Social, networking websites, websites providing real-time Stock, market data, and websites providing various other, services (e.g., websites offering storing and/or sharing, of images, files and so forth)., A website may be, •, , Personal website, , •, , Commercial website, , •, , E-Government, , •, , Non-profit organization website., , Static Website, A static website is one that has web pages stored on the, server in the format that is sent to a client web browser. It, is primarily coded in Hypertext Markup Language (HTML)., Simple forms or marketing examples of websites, such, as classic website, a five-page website or a brochure, website are often static websites, because they present, pre-defined, static information to the user. This may, include information about a company and its products, and services through text, photos, animations, audio/video, and interactive menus and navigation., This type of website usually displays the same information, to all visitors. Similar to handing out a printed brochure to, customers or clients, a static website will generally provide, consistent, standard information for an extended period of, time. Although the website owner may make updates, periodically, it is a manual process to edit the text, photos, and other content and may require basic website design, skills and software., Advantages, •, , Static Websites are easier to develop, , •, , Can be developed quickly, , •, , They are indexed easily by search engines as all the, web pages actually exist on the server, which is not, the case with dynamic websites., , Copyright @ NIMI Not to be Republished
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Disadvantages, , •, , Content Site: these sites create and sell of original, content to end-user. (e.g., Slate, About.com)., , •, , Static websites cannot do complex tasks required by, many online services., , •, , •, , Updating a whole site can be cumbersome and time, consuming., , Corporate website: used to provide information regarding, business, organization, or service., , •, , •, , An isolation of Data and Design is not provided in static, websites., , Commerce site (or eCommerce site): these sites are, designed for purchasing or selling goods, such as, Amazon.com, CSN Stores, and Overstock.com., , •, , Community site: sites where persons with similar, interests communicate to each other through chatting, and messaging or through soci message boards, such, as MySpace or Facebook., , •, , City Site: A site that shows information about a certain, city or town and events that takes place in that town., Usually created by the city council. For example,, Richmond.com is the geodomain for Richmond,, Virginia., , •, , Information site: contains content that is intended to, inform visitors, but not necessarily for commercial, purposes, such as: RateMyProfessors.com, Free, Internet Lexicon and Encyclopaedia. Most, government, educational and non-profit institutions, have an informational site., , •, , Mirror site: A complete reproduction of a website., , •, , News site: similar to an information site, but dedicated, to dispensing news and commentary., , •, , Personal homepage: run by an individual or a small, group such as a family that contains information or, any content that the individual wishes to include. These, are usually uploaded using a web hosting service such, as Geocities., , •, , Phish Site: a website created to fraudulently acquire, sensitive information, such as passwords and credit, card details, by disguising as a trustworthy person or, business (such as Social Security Administration,, PayPal) in an electronic communication., , •, , Political site: A site on which people may voice political, views., , •, , Rating site: A site on which people can praise or, disparage what is featured., , •, , Review site: A site on which people can post reviews, for products or services., , •, , School site: a site on which teachers, students, or, administrators can post information about current, events at or involving their school., , •, , Video sharing: A site that enables user to upload, videos, such as YouTube and Google Video., , •, , Search engine site: a site that provides general, information and is intended as a gateway for retrieving, other sites. Google, Yahoo and MSN are the most, widely known search engines., , •, , Shock site: includes images or other material that is, intended to be offensive to most viewers (e.g., rotten.com)., , Dynamic Website, A dynamic website is one that changes or customizes, itself frequently and automatically, based on certain, criteria., Dynamic websites can have two types of dynamic activity:, Code and Content. Dynamic code is invisible or behind, the scenes and dynamic content is visible or fully displayed, Advantages, •, , Can do more complex task required by online services., , •, , They are easier to update., , •, , Isolation of data and design allows programmers and, content writers to work independently., , Disadvantages, •, , Can take more time to build., , •, , Can be difficult to build., , •, , Dynamic websites are not indexed by search engines, easily, since they do not have actual web pages, present on the web server. With continuous, improvements in search engine technology, this, problem is now very much eliminated and you can, find that many dynamic websites are very well indexed, by search engines now a days., , A few such classifications are:, •, , •, , •, , Affiliate: enabled portal that renders not only its custom, CMS but also syndicated content from other content, providers for an agreed fee. There are usually three, relationship tiers. Affiliate Agencies (e.g., Commission, Junction), Advertisers (e.g., eBay) and consumer (e.g.,, Yahoo!)., Archive site: used to preserve valuable electronic, contents that are on verge of extinction. For examples:, Internet Archive, which since 1996 has preserved, billions of old and new web pages; and Google Groups,, which in early 2005 had preserved over 845,000,000, messages posted to Usenet news/discussion groups., Blog Site: sites generally used to post online diaries,, comments or views that may include discussion, forums (e.g., blogger, Xanga)., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 215
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•, , Warez: a site designed to host and let users download, copyrighted materials illegally., , •, , Web portal: a site is vehicle that provides a gateway to, other resources on the Internet or an intranet., , Web Pages, A web page or webpage is a Document or information, resource that is suitable for the world wide Web and can, be accessed through a web browser and displayed on a, computer display or mobile device. This information is, usually in HTML or XHTML format, and may provide, navigation bar to other web pages via Hyper text Hyper, link. Web pages frequently subsume other resources such, as Cascading Style Sheet, Client-side-scripting and, Images into their final presentation., Web pages may be retrieved from a local computer or, from a remote Web server. The web server may restrict, access only to a private network, e.g. a corporate Intranet, or it may publish pages on the World Wide Web. Web, pages are requested and served from web. Web server, using Hypertext Transfer Protocol (HTTP)., Web pages may consist of files of static text and other, Web content stored within the Web server 's file, system(Static Web page), or may be constructed by, Server-side scripting when they are requested (Dynamic, web page). Client-side scripting can make web pages more, responsive to user input once on the client browser., , Web Browser, A Web browser can have a Graphical User Interface, like, Internet Explorer, Mozilla Firefox, Google Chrome and, Opera (web browser), or can be Command Line Interface,, like Lynx (web browser) (Fig 1) or Links (web browser)., Web users with disabilities often use assistive, technologies and adaptive strategies to Web accessibility, web pages. Users may be colour blind, may or may not, want to use a mouse perhaps due to repetitive stress, injury or motor-neurone problems, may be deaf and, require audio to be captioned, may be blind and using a, Screen reader or display, may need screen magnification,, etc. Disabled and able-bodied users may disable the, download and viewing of images and other media, to, save time, network bandwidth or merely to simplify their, browsing experience., Users of mobile devices often have restricted displays and, bandwidth. Anyone may prefer not to use the fonts, font, sizes, styles and colour schemes selected by the web, page designer and may apply their own CSS styling to, the page. The World Wide Web Consortium (W3C) and, Web Accessibility Initiative (WAI) recommend that all web, pages should be designed with all of these options in mind., , Fig 1, , 216, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Downloading a Software from Internet, 1 Create a Temporary Files folder by opening My, Computer, double click on your hard drive (typically, the C: drive), then select File/New/Folder as on Fig 2., Fig 2, , 2 Type "Temporary File" and name it as on Fig 3., , Fig 3, , 3 Type "My SQL 5. 1 free download " from freeware, software website on internet., Note: As an example Choose "http://, dev.mysql.com/downloads/" select "My SQL, Community server" in download from the, opened site as on Fig 4, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 217
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Fig 4, , My Sql Community, , 4 Click "MySQL Community Server 5.1 " from looking for previous version option as on Fig 5, Fig 5, , 5 Choose "Windows (x86, 32-bit), MSI Installer Essentials - Recommended" and click download (Fig.6)., , 218, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 6, , Note: Save the "My SQL 5.1.63" in the created, Folder name " Temporary Folder", , documents (hypertext) and make web documents, interactive (such as with forms)., , 6 Burn the Downloaded "My SQL 5.1.63" in a CD ROM, for Installation., , HTML is a defined standard markup language. That, standard was developed by the World Wide Web, Consortium (W3C). It is based upon SGML (Standard, Generalized Markup Language). It is a language that uses, tags to define the structure of your text. Elements and, tags are defined by the < and > characters., , WEB LANGUAGES, Web languages are called as Markup languages are, designed for the processing, definition and presentation, of text. The language specifies code for formatting, both, the layout and style, within a text file. The code used to, specify the formatting are called tags, Four Types of Markup languages, 1 BML, , DHTML, Dynamic HTML is not really a new specification of HTML,, but rather a new way of looking at and controlling the, standard HTML codes and commands., When thinking of dynamic HTML, we need to remember, the qualities of standard HTML, especially that once a, page is loaded from the server, it will not change until, another request comes to the server. Dynamic HTML give, more control over the HTML elements and allows them, to change at any time, without returning to the Web server., , 2 HTML, 3 DHTML, 4 XML, BML (Better markup language), BML is essentially a simple macro language. Macros are, called blocks in BML. Blocks are defined in look files, and, are invoked in BML files. Blocks accept parameters and, are divided into several types, according to how parameters, are transmitted and how the definition of the block is able, to make use of them., HTML (Hyper text markup Language), HTML or HyperText Markup Language is the language of, the web. All web pages are written in HTML. HTML defines, the way that images, multimedia, and text are displayed, in web browsers. It includes elements to connect the, , There are four parts to DHTML:, •, •, •, •, , Document Object Model (DOM) (definition), Scripts, Cascading Style Sheets (CSS), XHTML, , DOM, The DOM is allows to access any part of Web page to, change it with DHTML. Every part of a Web page is, specified by the DOM and using its consistent naming, conventions can access them and change their properties., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 219
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Scripts, , Data binding, , Scripts written in either JavaScript or ActiveX are the two, most common scripting languages used to activate, DHTML. You use a scripting language to control the, objects specified in the DOM., , This is an IE only feature. Microsoft developed this to allow, easier access to databases from Web sites. It is very, similar to using a CGI to access a database, but uses an, ActiveX control to function., , Cascading Style Sheets, , XML, , CSS is used in DHTML to control the look and feel of the, Web page. Style sheets define the colors and fonts of, text, the background colors and images, and the, placement of objects on the page. Using scripting and, the DOM, we can change the style of various elements., , Extensible Markup Language (XML) is a markup language, that defines a set of rules for encoding documents in a, format that is bothhuman-readable and machine-readable., It is defined in the XML 1.0 Specification produced by the, W3C, and several other related specifications, all gratis, open standards. The design goals of XML emphasize, simplicity, generality, and usability over the Internet. It is a, textual data format with strong support via Unicode for the, languages of the world. Although the design of XML focuses, on documents, it is widely used for the representation of, arbitrary data structures, for example in web services, , XHTML, XHTML or HTML 4.x is used to create the page itself and, build the elements for the CSS and the DOM to work on., There is nothing special about XHTML for DHTML - but, having valid XHTML is even more important, as there, are more things working from it than just the browser., Features of DHTML, , Creating an HTML document, , There are four primary features of DHTML:, , Before start writing code to write a web page, it is a good, practice to plan ahead the appearance of the web page., An HTML document has two elements:, , 1 Changing the tags and properties, , 1 Document Content, , 2 Real-time positioning, , 2 Tags, , 3 Dynamic fonts (Netscape Communicator), 4 Data binding (Internet Explorer), Changing the tags and properties, This is one of the most common uses of DHTML. It allows, to change the qualities of an HTML tag depending on an, event outside of the browser (such as a mouse click, time,, or date, and so on). we can use this to preload information, onto a page, and not display it unless the reader clicks, on a specific link., Real-time postioning, Objects, images, and text moving around the Web page., This can allow we to play interactive games with the, readers or animate portions of the screen., Dynamic Fonts, This is a Netscape only feature. Netscape developed this, to get around the problem designers had with not knowing, what fonts would be on a reader's system. With dynamic, fonts, the fonts are encoded and downloaded with the page,, so that the page always looks how the designer intended, it to., , 220, , Document content is the information on a web page, that the user will see. That information could be text or, graphics., Tags are the HTML codes that control how the document, content will appear. The tags, in other words, will, determine whether the text will be bold, black or blue, or, of font type Time New Roman or Airal., Start Notepad, To start Notepad go to:, Start, All Programs, Accessories, Notepad, Edit Your HTML with Notepad (Fig 7), Type your HTML code into your Notepad:, Save Your HTML, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Fig 7, , Select Save as.. in Notepad's file menu., When you save an HTML file, you can use either the .htm, or the .html file extension., Save the file in a folder that is easy to remember, , Start your web browser and open your html file from the, File, Open menu, or just browse the folder and doubleclick your HTML file., The result should look much like this: (Fig 8), , Run the HTML in Your Browser, Fig 8, , Structure of Markup Language, An HTML document has two* main parts:, 1 head. The head element contains title and meta data, of a web document., 2 body. The body element contains the information that, you want to display on a web page., , To make your web pages compatible with HTML 4, you, need to add a document type declaration (DTD) before the, HTML element. Many web authoring software add DTD, and basic tags automatically when you create a new web, page., In a web page, the first tag (specifically, <html>) indicates, the markup language that is being used for the document., The <head> tag contains information about the web page., Lastly, the content appears in the <body> tag. (Fig 9), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 221
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Fig 9, , The <!DOCTYPE> Declaration, There are many different documents on the web. A browser, can only display a document correctly, if it knows what, kind of document it is., There are also many different versions of HTML, and a, browser can only display an HTML page 100% correctly, if it knows the exact HTML version used in the page. This, is what <!DOCTYPE> is used for., , •, , Provides a title for the page when it is added to, favorites., , •, , Displays a title for the page in search-engine results., , HTML Element Syntax, •, , An HTML element starts with a start tag / opening tag, , •, , An HTML element ends with an end tag / closing tag, , •, , <!DOCTYPE> is not an HTML tag. It is an information (a, declaration) to the browser about what version the HTML, is written in., , The element content is everything between the start, and the end tag, , •, , Some HTML elements have empty content, , •, , Empty elements are closed in the start tag, , The HTML <head> Element, , •, , Most HTML elements can have attributes, , The <head> element is a container for all the head, elements. Elements inside <head> can include scripts,, instruct the browser where to find style sheets, provide, meta information, and more., The following tags can be added to the head section: <title>,, <base>, <link>, <meta>, <script>, and <style>., , HTML Headings, HTML headings are defined with the <h1> to <h6> tags., Examples, <html>, <body>, <h1>This is heading 1</h1>, , The HTML <title> Element, The <title> tag defines the title of the document., , <h2>This is heading 2</h2>, <h3>This is heading 3</h3>, , The title element is required in all HTML/XHTML, documents., , <h4>This is heading 4</h4>, , The title element:, , <h6>This is heading 6</h6>, , •, , Defines a title in the browser toolbar., , 222, , <h5>This is heading 5</h5>, </body>, </html>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 992 : Result, , Fig 10, , This is heading 1, This is heading 2, This is heading 3, This is heading 4, This is heading 5, This is heading 6, HTML Paragraphs, HTML paragraphs are defined with the <p> tag., , HTML Attributes, , <html>, , •, , HTML elements can have attributes, , <body>, , •, , Attributes provide additional information about an, element, , <p>This is a paragraph.</p>, , •, , Attributes are always specified in the start tag, , <p>This is a paragraph.</p>, , •, , Attributes come in name/value pairs like:, name="value", , <p>This is a paragraph.</p>, , </body>, </html>, , Attribute Example, , Examples, This is a paragraph., , HTML links are defined with the <a> tag. The link address, is specified in the href attribute:, , This is a paragraph., , <html>, , This is a paragraph., , <body>, , HTML Links, , <a href="http://www.yahoo.com">, , HTML links are defined with the <a> tag., , This is a link</a>, , <html>, , </body>, , <body>, , </html>, , <a href="http://www.facebook.com">, , Result, , This is a link</a>, , This is the link, , </body>, , By clicking the link yahoo home page appears (Fig 11)., , </html>, , Formatting, , Result, , Create Line Breaks - The <br /> Element:, , This is a link, By clicking the link it shows the facebook login page, HTML Images, HTML images are defined with the <img> tag., , Whenever the <br /> element, anything following it starts, on the next line. This tag is an example of an empty, element, where you do not need opening and closing tags,, as there is nothing to go in between them., , <html>, <body>, <img src="w3schools.jpg" width="104" height="142" />, </body>, </html>, Result (Fig 10), , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 223
Page 993 : Fig 11, , Example:, , Soft Hyphens:, , Hello<br/>, You come most carefully upon your hour.<br/>, Thanks<br/>, , <p style="text-align: justify;"> The morbid fear of, the number 13, or triskaidekaphobia, has plagued, some important historic figures like Mahamiya and, Nanao.</p>, , Mahnaz, Result, , This will produce following result:, , Hello, You come most carefully upon your hour., Thanks, Mahnaz, , Example for soft hyphen - The morbid fear of the, number 13, or triskaidekaphobia, has plagued some, important historic figures like Mahamiya and Nanao., Preserve Formatting - The <pre> Element:, , To Become, Centring Content - The <center> Element:, You can use <center> tag to put any content in the center, of the page or any table cell., Example:, <p>This is not in the center.</p>, <center>, <p>This is in the center.</p>, </center>, This will produce following result:, This is not in the center., This is in the center., , 224, , Occasionally, you will want to allow a browser to hyphenate, long words to better justify a paragraph. For example,, consider the following code and its resulting output., , Sometimes you want your text to follow the exact format, of how it is written in the HTML document. In those cases,, you can use the preformatted tag (<pre>)., Any text between the opening <pre> tag and the closing, </pre> tag will preserve the formatting of the source, document., <pre>, function testFunction( strText ){, alert (strText), }, </pre>, This will produce following result:, function testFunction( strText ){, alert (strText), }, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 994 : Horizontal Rules - The <hr /> Element, , Underlined Text - The <u> Element:, , Horizontal rules are used to visually break up sections of, a document. The <hr> tag creates a line from the current, position in the document to the right margin and breaks, the line accordingly., , Anything that appears in a <u>...</u> element is displayed, with underline, like the word underlined here:, , For example you may want to give a line between two, paragraphs as follows:, , <p>The following word uses a <u>underlined</, u> typeface.</p>, This will produce following result:, , <p>This is paragraph one and should be on top</p>, , The following word uses a underlined typeface., , <hr />, , Strike Text - The <strike> Element:, , <p>This is paragraph two and should be at bottom</, p>, This will produce following result:, This is paragraph one and should be on top, This is paragraph two and should be at bottom, Again <hr /> tag is an example of an empty element,, where you do not need opening and closing tags, as there, is nothing to go in between them., Note: The <hr /> element has a space between, the characters hr and the forward slash. If you, omit this space, older browsers will have, trouble rendering the line break, while if you, miss the forward slash character and just use, <hr> it is not valid XHTML, Presentational Tags:, If you use a word processor, you are familiar with the, ability to make text bold, italicized, or underlined; these, are just three of the ten options available to indicate how, text can appear in HTML and XHTML., Bold Text - The <b> Element:, Anything that appears in a <b>...</b> element is displayed, in bold, like the word bold here:, <p>The following word uses a <b>bold</b>, typeface.</p>, This will produce following result:, The following word uses a bold typeface., Italic Text - The <i> Element:, Anything that appears in a <i>...</i> element is displayed, in italicized, like the word italicized here:, <p>The following word uses a <i>italicized</i>, typeface.</p>, This will produce following result:, The following word uses a italicized typeface., , Anything that appears in a <strike>...</strike> element is, displayed with strikethrough, which is a thin line through, the text:, <p>The, following, word, uses, a, <strike>strikethrough</strike> typeface.</p>, This will produce following result:, The following word uses a strikethrough typeface., Monospaced font - The <tt> Element:, The content of a <tt> element is written in monospaced, font. Most fonts are known as variable-width fonts, because different letters are of different widths (for, example, the letter m is wider than the letter i). In a, monospaced font, however, each letter is the same width., <p>The, following, word, uses, <tt>monospaced</tt> typeface.</p>, , a, , This will produce following result:, The following word uses a monospaced typeface., Superscript Text - The <sup> Element:, The content of a <sup> element is written in superscript;, the font size used is the same size as the characters, surrounding it but is displayed half a character.s height, above the other characters., <p>The, following, word, uses, <sup>superscript</sup> typeface.</p>, , a, , This will produce following result:, The following word uses a superscript typeface., Subscript Text - The <sub> Element:, The content of a <sub> element is written in subscript;, the font size used is the same as the characters surrounding, it, but is displayed half a character.s height beneath the, other characters., <p>The, following, word, uses, <sub>subscript</sub> typeface.</p>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , a, , 225
Page 995 : This will produce following result:, The following word uses a subscript typeface., Larger Text - The <big> Element:, The content of the <big> element is displayed one font, size larger than the rest of the text surrounding it., <p>The following word uses a <big>big</big>, typeface.</p>, , HTML Hyperlinks (Links), A hyperlink (or link) is a word, group of words, or image, that you can click on to jump to a new document or a new, section within the current document., When you move the cursor over a link in a Web page,, the arrow will turn into a little hand., Links are specified in HTML using the <a> tag., , This will produce following result:, , The <a> tag can be used in two ways:, , The following word uses a big typeface., , 1 To create a link to another document, by using the, href attribute, , Smaller Text - The <small> Element:, The content of the <small> element is displayed one font, size smaller than the rest of the text surrounding it., <p>The following word uses a <small>small</, small> typeface.</p>, , 2 To create a bookmark inside a document, by using, the name attribute, The HTML code for a link is simple. It looks like this:, <a href="url">Link text</a>, , This will produce following result:, , The href attribute specifies the destination of a link., , The following word uses a small typeface., , <a href="http://www.yahoo.com/">Visit yahoo</a>, , Styling HTML with CSS, , which will display like this: Visit yahoo.com, , CSS was introduced together with HTML 4, to provide a, better way to style HTML elements., , Clicking on this hyperlink will send the user to Yahoo, homepage., , CSS can be added to HTML in the following ways:, , The "Link text" doesn't have to be text. It can be an image, or any other HTML element., , •, , Inline - using the style attribute in HTML elements, , •, , Internal - using the <style> element in the <head>, section, , •, , External - using an external CSS file, , <html>, <body style="background-color:PowderBlue;">, <h1>Look! Styles and colors</h1>, <p style="font-family:verdana;color:red;">, This text is in Verdana and red</p>, <p style="font-family:times;color:green;">, This text is in Times and green</p>, <p style="font-size:30px;">This text is 30 pixels high</, p>, </body>, , HTML Links - The target Attribute, The target attribute specifies where to open the linked, document., The example below will open the linked document in a, new browser window or a new tab:, Example, <a href="http://www.yahoo.com/" target="_blank">Visit, yahoo !</a>, <html>, <body>, <a href="http://www.yahoo.com" target="_blank">Visit, yahoo.com!</a>, , </html>, , <p>If you set the target attribute to "_blank", the link will, open in a new browser window/tab.</p>, , Result:, , </body>, , Look! Styles and colors, , </html>, , This text is in Verdana and red, This text is in Times and green, This text is 30 pixels high, 226, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 996 : Result, , <img src="boat.gif" alt="Big Boat" />, , Visit yahoo.com!, , The alt attribute provides alternative information for an image, if a user for some reason cannot view it (because of slow, connection, an error in the src attribute, or if the user uses, a screen reader)., , If you set the target attribute to "_blank", the link will open, in a new browser window/tab., HTML Images - The <img> Tag and the Src Attribute, In HTML, images are defined with the <img> tag., The <img> tag is empty, which means that it contains, attributes only, and has no closing tag., To display an image on a page, you need to use the src, attribute. Src stands for "source". The value of the src, attribute is the URL of the image you want to display., Syntax for defining an image:, <img src="url" alt="some_text"/>, The URL points to the location where the image is stored., An image named "bamboo. gif", located in the "images", directory on "www.w3schools.com" has the URL: http://, www.backgroundlabs.com/index.php?search=bamboo., The browser displays the image where the <img> tag, occurs in the document. If you put an image tag between, two paragraphs, the browser shows the first paragraph,, then the image, and then the second paragraph., HTML Images - The Alt Attribute, The required alt attribute specifies an alternate text for an, image, if the image cannot be displayed., The value of the alt attribute is an author-defined text:, , HTML Images - Set Height and Width of an Image, The height and width attributes are used to specify the, height and width of an image., The attribute values are specified in pixels by default:, <img src="rose.jpg" alt="Rose" width="304" height="228", />, Note: It is a good practice to specify both the height and, width attributes for an image. If these attributes are set,, the space required for the image is reserved when the, page is loaded. However, without these attributes, the, browser does not know the size of the image. The effect, will be that the page layout will change during loading, (while the images load)., If an HTML file contains ten images - eleven files are, required to display the page right. Loading images takes, time, so my best advice is: Use images carefully., When a web page is loaded, it is the browser, at that, moment, that actually gets the image from a web server, and inserts it into the page. (Fig 12) Therefore, make sure, that the images actually stay in the same spot in relation, to the web page, otherwise your visitors will get a broken, link icon. The broken link icon is shown if the browser, cannot find the image., , Fig 12, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 227
Page 997 : <html>, , All major browsers display the text in the <th> element as, bold and centered., , <body>, , <table border="1">, , <h2>Friendship Card</h2>, <img border="0" src="/images/Rose.jpg" alt="Rose", width="304" height="228" />, , <tr>, <th>Header 1</th>, , </body>, , <th>Header 2</th>, , </html>, , </tr>, , HTML Tables, , <tr>, , Tables are defined with the <table> tag., , <td>row 1, cell 1</td>, , A table is divided into rows (with the <tr> tag), and each, row is divided into data cells (with the <td> tag). td stands, for "table data," and holds the content of a data cell. A, <td> tag can contain text, links, images, lists, forms, other, tables, etc., , <td>row 1, cell 2</td>, , Table Example, , </tr>, <tr>, <td>row 2, cell 1</td>, <td>row 2, cell 2</td>, , <table border="1">, , </tr>, , <tr>, , </table>, , <td>row 1, cell 1</td>, , How the HTML code above looks in your browser:, , <td>row 1, cell 2</td>, </tr>, <tr>, <td>row 2, cell 1</td>, , Header 1, , Header 2, , row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , <td>row 2, cell 2</td>, , HTML Unordered Lists, , </tr>, , An unordered list starts with the <ul> tag. Each list item, starts with the <li> tag., , </table>, How the HTML code above looks in a browser:, row 1, cell 1, , row 1, cell 2, , row 2, cell 1, , row 2, cell 2, , HTML Tables and the Border Attribute, If you do not specify a border attribute, the table will be, displayed without borders. Sometimes this can be useful,, but most of the time, we want the borders to show., , The list items are marked with bullets (typically small black, circles)., <ul>, <li>Coffee</li>, <li>Milk</li>, </ul>, How the HTML code above looks in a browser:, , To display a table with borders, specify the border attribute:, , •, , Coffee, , <table border="1">, , •, , Milk, , <tr>, , HTML Ordered Lists, , <td>Row 1, cell 1</td>, , An ordered list starts with the <ol> tag. Each list item, starts with the <li> tag., , <td>Row 1, cell 2</td>, , The list items are marked with numbers., , </tr>, , <ol>, , </table>, , <li>Coffee</li>, , HTML Table Headers, Header information in a table are defined with the <th>, tag., , <li>Milk</li>, </ol>, How the HTML code above looks in a browser:, 1 Coffee, , 228, , 2 Milk, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 998 : HTML Definition Lists, A definition list is a list of items, with a description of each, item., , When used together with CSS, the <div> element can be, used to set style attributes to large blocks of content., , The <dl> tag is used in conjunction with <dt> (defines the, item in the list) and <dd> (describes the item in the list):, , Another common use of the <div> element, is for document layout. It replaces the "old way" of defining layout, using tables. Using tables is not the correct use of the, <table> element. The purpose of the <table> element is, to display tabular data., , <dl>, , The HTML <span> Element, , <dt>Coffee</dt>, , The HTML <span> element is an inline element that can, be used as a container for text., , The <dl> tag defines a definition list., , <dd>- black hot drink</dd>, <dt>Milk</dt>, <dd>- white cold drink</dd>, </dl>, How the HTML code above looks in a browser:, Coffee - black hot drink, Milk- white cold drink, Note : Inside a list item you can put text, line, breaks, images, links, other lists, etc., , The <span> element has no special meaning., When used together with CSS, the <span> element can, be used to set style attributes to parts of the text., HTML Grouping Tags, Tag, , Description, , <div>, , Defines a div, , <span>, , Defines a span, , HTML Layout, Website Layouts, , HTML List Tags, Tag, , Description, , <ol>, , Defines an ordered list, , <ul>, , Defines an unordered list, , <li>, , Defines a list item, , <dl>, , Defines a definition list, , <dt>, , Defines an item in a definition list, , <dd>, , Defines a description of an item in a, definition list, , HTML elements can be grouped together with <div> and, <span>, , Most websites have put their content in multiple columns, (formatted like a magazine or newspaper)., Multiple columns are created by using <div> or <table>, elements. CSS are used to position elements, or to create backgrounds or colorful look for the pages., HTML Layouts - Using <div> Elements, The div element is a block level element used for grouping, HTML elements., The following example uses five div elements to create a, multiple column layout, creating the same result as in the, previous example:, Example, , HTML Block Elements, , <div>, , Most HTML elements are defined as block level elements, or as inline elements., , <!DOCTYPE html>, , Block level elements normally start (and end) with a new, line when displayed in a browser., , <body>, , Examples: <h1>, <p>, <ul>, <table>, HTML Inline Elements, Inline elements are normally displayed without starting a, new line., Examples: <b>, <td>, <a>, <img>, The HTML <div> Element, The HTML <div> element is a block level element that can, be used as a container for grouping other HTML elements., The <div> element has no special meaning. Except that,, because it is a block level element, the browser will display a line break before and after it., , <html>, <div id="container" style="width:500px">, <div id="header" style="background-color:#FFA500;">, <h1 style="margin-bottom:0;">Main Title of Web Page</, h1></div>, <divid="menu"style="backgroundcolor:#FFD700;height:200px;width:100px;float:left;">, <b>Menu</b><br />, HTML<br />, CSS<br />, JavaScript</div>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 229
Page 999 : <div, id="content", style="backgroundcolor:#EEEEEE;height:200px;width:400px;float:left;">, Content goes here</div>, <div, id="footer", style="backgroundcolor:#FFA500;clear:both;text-align:center;">, , </div>, </div>, </body>, </html>, Result (Fig 13), , Fig 13, , HTML Forms, , First name: <input type="text" name="firstname" /><br />, , HTML forms are used to pass data to a server., , Last name: <input type="text" name="lastname" />, , A form can contain input elements like text fields,, checkboxes, radio-buttons, submit buttons and more. A, form can also contain select lists, textarea, fieldset, legend, and label elements., , </form>, , The <form> tag is used to create an HTML form:, , Last name:, , <form>., , How the HTML code above looks in a browser:, First name:, , Note: The form itself is not visible. Also note, that the default width of a text field is 20, characters., , input elements., </form>, HTML Forms - The Input Element, , Password Field, , The most important form element is the input element., , <input type="password" /> defines a password field:, , The input element is used to select user information., , <form>, , An input element can vary in many ways, depending on, the type attribute. An input element can be of type text, field, checkbox, password, radio button, submit button,, and more., , Password: <input type="password" name="pwd" />, , The most used input types are described below., , Password:, , Text Fields, <input type="text" /> defines a one-line input field that a, user can enter text into:, , </form>, How the HTML code above looks in a browser:, , Note: The characters in a password field are, mased (shown as asterisks or circles), , <form>, , 230, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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Radio Buttons, <input type="radio" /> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of, choices:, <form>, , If you type some characters in the text field above, and, click the "Submit" button, the browser will send your input, to a page called "html_form_action.asp". The page will, show you the received input., HTML Iframes, , <input type="radio" name="sex" value="male" /> Male<br/>, <input type="radio" name="sex" value="female" /> Female, </form>, How the HTML code above looks in a browser:, , Syntax for adding an iframe:, <iframe src="URL"></iframe>, The URL points to the location of the separate page., , Male, , Iframe - Set Height and Width, , Female, , The height and width attributes are used to specify the, height and width of the iframe., , Checkboxes, <input type="checkbox" /> defines a checkbox., Checkboxes let a user select ONE or MORE options of a, limited number of choices., <form>, <input type="checkbox" name="vehicle" value="Bike" />, I have a bike<br />, <input type="checkbox" name="vehicle" value="Car" /> I, have a car, , The attribute values are specified in pixels by default, but, they can also be in percent (like "80%")., Example, <!DOCTYPE html>, <html>, <body>, <iframe src="demo_iframe.htm", height="200"></iframe>, , width="200", , </body>, , </form>, How the HTML code above looks in a browser:, , </html>, It will appear as shown in Fig 14., , I have a bike, , Iframe - Remove the Border, , I have a car, , The frameborder attribute specifies whether or not to display, a border around the iframe., , Submit Button, <input type="submit" /> defines a submit button., A submit button is used to send form data to a server. The, data is sent to the page specified in the form's action, attribute. The file defined in the action attribute usually, does something with the received input:, <form name="input" action="html_form_action.asp", method="get">, Username: <input type="text" name="user" />, <input type="submit" value="Submit" />, , Set the attribute value to "0" to remove the border:, Example, <iframe src="demo_iframe.htm" frameborder="0"></, iframe>, Use iframe as a Target for a Link, An iframe can be used as the target frame for a link., The target attribute of a link must refer to the name attribute, of the iframe:, , </form>, How the HTML code above looks in a browser:, Username:, , Submit, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 231
Page 1001 : Fig 14, , Example, , HTML Colour, , <iframe src="demo_iframe.htm" name="iframe_a"></, iframe>, < p > < a h r e f = " h t t p : / / w w w. y a h o o . c o m ", target="iframe_a">yahoo.com</a></p>, HTML iframe Tag, , Color Values, HTML colors are defined using a hexadecimal notation, (HEX) for the combination of Red, Green, and Blue color, values (RGB)., The lowest value that can be given to one of the light sources, is 0 (in HEX: 00). The highest value is 255 (in HEX: FF)., , Tag, , Description, , HEX values are specified as 3 pairs of two-digit numbers,, starting with a # sign., , <iframe>, , Defines an inline sub window (frame), , Color Values (Fig 15), , Fig 15, , Color, , Color HEX, , Color RGB, , #000000, , rgb(0,0,0), , #FF0000, , rgb(255,0,0), , #00FF00, , rgb(0,255,0), , #0000FF, , rgb(0,0,255), , #FFFF00, , rgb(255,255,0), , #00FFFF, , rgb(0,255,255), , #FF00FF, , rgb(255,0,255), , #C0C0C0, , rgb(192,192,192), , #FFFFFF, , rgb(255,255,255), , <!DOCTYPE html>, , Color set by using hex value, , <html>, , </p>, , <body>, , <p style="background-color:rgb(255,255,0)">, , <p style="background-color:#FFFF00">, , Color set by using rgb value, , 232, , </p>, IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
Page 1002 : <p style="background-color:yellow">, Color set by using color name, </p>, </body>, , <noscript>Sorry, your browser does not support, JavaScript!</noscript>, <p>A browser without support for JavaScript will show the, text in the noscript element.</p>, </body>, , </html>, , </html>, , Result, Color set by using hex value, Color set by using rgb value, Color set by using color name, DHTML, The HTML script Element, The <script> tag is used to define a client-side script,, such as a JavaScript., The script element either contains scripting statements, or it points to an external script file through the src attribute., The required type attribute specifies the MIME type of the, script., Common uses for JavaScript are image manipulation, form, validation, and dynamic changes of content., The script below writes Hello World! to the HTML output:, Example, <script type="text/javascript">, document.write("Hello World!"), </script>, The HTML noscript Element, The <noscript> tag is used to provide an alternate content, for users that have disabled scripts in their browser or, have a browser that doesn't support client-side scripting., The noscript element can contain all the elements that, you can find inside the body element of a normal HTML, page., The content inside the noscript element will only be, displayed if scripts are not supported, or are disabled in, the user's browser:, Example, , Result, Hello World!, A browser without support for JavaScript will show the text, in the noscript element., HTML Script Tags, Tag, , Description, , <script>, , Defines a client-side script, , <noscript>, , Defines an alternate content for users, that do not support client-side scripts, , HTML Entities, Some characters are reserved in HTML., It is not possible to use the less than (<) or greater than, (>) signs in your text, because the browser will mix them, with tags., To actually display reserved characters, we must use, character entities in the HTML source code., A character entity looks like this:, &entity_name;, OR, &#entity_number;, Non-breaking Space, A common character entity used in HTML is the nonbreaking space ( )., Browsers will always truncate spaces in HTML pages. If, you write 10 spaces in your text, the browser will remove, 9 of them, before displaying the page. To add spaces to, your text, you can use the character entity., HTML Useful Character Entities, , <!DOCTYPE html>, , Note: Entity names are case sensitive!, , <html>, <body>, <script type="text/javascript">, , HTML Uniform Resource Locators, , document.write("Hello World!"), , A URL is another word for a web address., , </script>, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 233
Page 1003 : Result, , URL - Uniform Resource Locator, , Entity, Name, , Entity, Number, , non-breaking, space, , , ,  , , When you click on a link in an HTML page, an underlying, <a> tag points to an address on the world wide web., , <, , less than, , <, , <, , A Uniform Resource Locator (URL) is used to address a, document (or other data) on the world wide web., , >, , greater than, , >, , >, , Explanation:, , &, , ampersand, , &, , &, , •, , Scheme - defines the type of Internet service. The, most common type is http, , ¢, , cent, , ¢, , ¢, , •, , £, , pound, , £, , £, , Host - defines the domain host (the default host for, http is www), , ¥, , yen, , ¥, , ¥, , •, , Domain - defines the Internet domain name, like, w3schools.com, , •, , euro, , €, , €, , •, , §, , section, , §, , §, , Port - defines the port number at the host (the default, port number for http is 80), , ©, , copyright, , ©, , ©, , •, , ®, , registered, trademark, , ®, , ®, , Path - defines a path at the server (If omitted, the, document must be stored at the root directory of the, web site), , •, , Filename - defines the name of a document/resource, , trademark, , ™, , ™, , Description, , ™, , Common URL Schemes, , A URL can be composed of words, such as, "w3schools.com", or an Internet Protocol (IP) address:, 192.68.20.50. Most people enter the name of the website, when surfing, because names are easier to remember than, numbers., Scheme, , The table below lists some common schemes:, , Short for...., , Which pages will the scheme be used for..., , http, , HyperText Transfer Protocol, , Common web pages starts with http://. Not encrypted, , https, , Secure HyperText Transfer, Protocol, , Secure web pages. All information exchanged are encrypted, , ftp, , File Transfer Protocol, , For downloading or uploading files to a website. Useful for, domain maintenance, , file, , A file on your computer, , URL Encoding, , XML Structure, , URLs can only be sent over the Internet using the ASCII, character-set., , The XML structure including the document parts, the, prologue, and provides a simple XML example document., , Since URLs often contain characters outside the ASCII, set, the URL has to be converted into a valid ASCII format., , Document Parts, , URL encoding replaces non ASCII characters with a "%", followed by two hexadecimal digits., , •, , Prolog, , •, , Document Element (root element), , URLs cannot contain spaces. URL encoding normally, replaces a space with a + sign., 234, , The Prologue, The prologue, equivalent to the header in HTML, may, include the following:, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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•, , •, , •, , An XML declaration (optional) such as:, , TYPES OF Web Hosting, , <?xml version="1.0"?>, , There are four types of Web hosting, , A DTD or reference to one (optional). An example, reference to an external DTD file:, , 1 Free hosting, 2 Dedicated hosting, , <!DOCTYPE LANGLIST SYSTEM "langlist.dtd">, , 3 Shared (Virtual) hosting, , Processing instructions - An example processing, instruction that causes style to be determined by a, style sheet:, , 4 Collocated Hosting, , <?xml-stylesheettype="text/css", href="xmlstyle.css"?>, An XML Example, Therefore a complete well formed XML document may look, like:, <?xml version="1.0"?>, <LAND>, <FOREST>, <TREE>Oak</TREE>, <TREE>Pine</TREE>, <TREE>Maple</TREE>, </FOREST>, <MEADOW>, <GRASS>Bluegrass</GRASS>, <GRASS>Fescue</GRASS>, , Free hosting, Free web hosting is best suited for small sites with low, traffic, like personal sites. It is not recommended for high, traffic or for real business. Technical support is often, limited, and technical options are few., Dedicated Hosting, With dedicated hosting, your web site is hosted on a, dedicated server. Dedicated hosting is the most expensive, option. This option is best suited for large web sites with, high traffic, and web sites that use special software., Dedicated hosting to be very powerful and secure, with, almost unlimited software solutions., Shared (Virtual) Hosting, Shared hosting is very cost effective., With shared hosting, your web site gets its own domain, name, and is hosted on a powerful server along with maybe, 100 other web sites. Shared solutions often offer multiple, software solutions like e-mail, database, and different editing, options. Technical support tends to be good., Collocated Hosting, , Result, , Collocation means "co-location". Collocated hosting lets, place own web server on the premises (locations) of a, service provider. This is pretty much the same as running, own server in your own office, only that it is located at a, place better designed for it. Most likely an ISP will have, dedicated resources like high-security against fire and, vandalism, regulated backup power, dedicated Internet, connections and more., , Oak Pine Maple Bluegrass Fescue Rye, , Web Server, , <GRASS>Rye</GRASS>, </MEADOW>, </LAND>, The LAND element, above, is the root element., , Web Elements, A web page, as an information set, can contain numerous, types of information, which is able to be seen, heard or, interact by the End-user, Web Hosting, A web hosting service is a type of Internet hosting service, that allows individuals and organizations to make their, Website accessible via the World Wide Web. Web hosts, are companies that provide space on a Server (computing), owned or leased for use by clients, as well as providing, Internet connectivity, typically in a data centre. Web hosts, can also provide data centre space and connectivity to, the Internet for other servers located in their data centre,, called Collocation., , A Web server is a program that, using the client server, model and the World Wide Web's Hypertext Transfer, Protocol ( HTTP), serves the files that form Web pages to, Web users (whose computers contain HTTP clients that, forward their requests). Every computer on the Internet, that contains a Web site must have a Web server program., Two leading Web servers are Apache, the most widelyinstalled Web server, and Microsoft's Internet Information, Server (IIS). Other Web servers include Novell's Web Server, for users of its Netware operating system and IBM's family, of Lotus Domino servers, primarily for IBM's OS390 and, AS-400 customers., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished, , 235
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Web servers often come as part of a larger package of, Internet- and intranet-related programs for serving e-mail,, downloading requests for File Transfer Protocol (FTP) files,, and building and publishing Web pages. Considerations, in choosing a Web server include how well it works with, the operating system and other servers, its ability to handle, server-side programming, security characteristics, and, publishing, search engine, and site building tools that may, come with it., , Application Server, Also called an appserver, and application server (Fig 16), is a program that handles all application operations, between users and an organization's backend business, applications or database. An application server is typically, used for complex transaction-based applications. To, support high-end needs, an application server has to have, built-in redundant, monitor for high-availability, highperformance distributed application services and support, for complex database access., , Fig 16, , Database Server, Database server (Fig 17) is the term used to refer to the, back-end system of a database application using client-, , 236, , server architecture. The back-end, sometimes called a, database server, performs tasks such as data analysis,, storage, data manipulation, archiving, and other non-user, specific tasks., , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.82 - 1.12.92, , Copyright @ NIMI Not to be Republished
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IT & ITES, COPA - Designing Static WebPages, , Related Theory for Exercise 1.12.93, , Introduction to CMS and web authoring tools, Objectives: At the end of this lesson you shall be able to, • explain the meaning of content management System., • list some of the popular CMSes., • explain the use and main features of kompozer web authoring tool., Definition of CMS:, , •, , CMS Stands for "Content Management System." A CMS, is a software tool that allows you to create, edit, and publish content., , Weebly - a web-based platform for building simple personal and business websites, , •, , Wix - a collection of web publishing tools for creating a, highly customizable website, , Description of CMS:, The goal of a CMS is to provide an intuitive user interface, for building and modifying webpage content. Each CMS, also provides a web publishing tool that allows one or more, users to publish updates live on the Web. The editing component is called the content management application, (CMA), while the publishing tool is called the content delivery application (CDA). These two components are integrated together in a CMS to streamline the web development process., In terms of web publishing, content can be simple text,, photos, music, video, documents, or just about anything, you can think of. While early CMS software was used to, manage documents and local computer files, most CMS, systems are now designed exclusively to manage content on the Web. A major advantage of using a CMS is, that it requires almost no technical skill or knowledge to, manage., Content management systems are available as installable, applications and web-based user interfaces. The use of a, web interfacesimplifies the website updating process., Additionally, most web-based CMSes are updated automatically, ensuring all users have the latest tools to manage their content., A major advantage of using a CMS is that it requires almost no technical skill or knowledge to manage. Since, the CMS manages all your content, you don't have to., There are several web-based CMS tools available today., The following are some of the most popular ones:, •, , WordPress - free web software designed for creating, template-based websites or blogs, , •, , Blogger - Google's blogging tool designed specifically, for maintaining a blog, , •, , Joomla - a flexible web publishing tool that supports, custom databases and extensions, , •, , Drupal - an open source platform often used for developing community-based sites, , Introduction to WSYIWYG web authoring tools, WYSIWYG stands for "What You See Is What You Get"., In such editors you edit not directly the source code of, your documents, but its presentation as it will appear in, the final document. So instead of writing blocks of code, manually (as you e.g. would do it in Word or Notepad),, you manipulate with design components using an editor, window. This means that you view something very similar, to the final result while the document or image is being, created., There are many easy-to-use WYSIWYG programs having, all the tools needed to create a complex and fully functional websites, even by beginners. These sites even have, options to work with HTML code be it design or editing.It, is easier to create a Web site with an HTML editor, as, software developers continue to add tools that let you develop advanced features with style.Many WSYIWYG web, authoring tools offer advanced features to integrate Dynamic HTML or many other features into a site with an, elegant and consistent design., Introduction to Kompozer, KompoZer is a complete Web Authoring System that combines web file management and easy-to-use, WYSIWYGweb page editing capabilities found in Microsoft, FrontPage, Adobe DreamWeaver and other high end programs. With kompozer you can create web pages and, manage a website with no technical expertise or knowledge of HTML., A useful feature of Kompozer is that you can use it to, publish your web pages to a web hosting server. You just, need to know your FTP account username and password, as well as the site URL and Kompozer will log in and, place your web pages on the server., KompoZer's File Menu contains menu items for all major, operations possible while using it. KompoZer's tool bar, user interface consists of:, , Copyright @ NIMI Not to be Republished, , 237
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Composition Toolbar, , •, , Format Toolbar, , •, , Tab Browser Toolbar, , •, , Edit Mode Toolbar, , •, , Status Toolbar, , Edit Mode Toolbar(Refer Fig.4), The Edit Mode Toolbar indicates the viewing mode which, is presently active for the current document. Available viewing modes are the Normal view, HTML Tags view, HTML, source view and the Preview mode. You can easily change, your viewing mode by simply clicking any of the other, three with the mouse., , Composition Toolbar, The Composition Toolbar consists of buttons for the most, used major operations. Below is the a snapshot of the, default Composition Toolbar with text below each button, indicating the respective button's function. (Refer Fig.1), copa 1308201, , Fig 1, , Format Toolbar(Refer Fig.2), , copa 1308204, , Status Toolbar(Refer Fig.5), KompoZer's status bar shows the position of the cursor, with respect to the HTML tag hierarchy. You can easily, edit/assign the properties of any particular tag in the status bar just by right clicking and choosing the desired, option. Simple left-click of the mouse on a tag in status, bar selects the text surrounded by that tag., Fig 5, , copa 1308202, , The Format Toolbar is a very useful tool while editing web, pages with KompoZer. With the Format Toolbar you can, apply paragraph format, choose a font, change foreground, or background colour, increase or decrease size, and, emphasize a block of text. You can also create ordered or, unordered lists and justify a block of text to left, right or, centre. To know which button does what just hover your, mouse over the button and a tool tip will appear indicating, the function of the button., , Fig 4, , Fig 2, , Tab Browser Toolbar(Refer Fig.3), KompoZer allows you to simultaneously edit multiple web, documents using different tabs for each opened document., Having multiple tabs gives a cleaner look to your desktop, as it is not cluttered when multiple windows are used for, each document. As a visual indicator a "red floppy icon", icon appears for pages which have been edited but not, saved yet., Fig 3, copa 1308203, , 238, , IT & ITES : COPA - (NSQF Level - 4): Related Theory for Exercise 1.12.93, , Copyright @ NIMI Not to be Republished, , copa 1308205, , •
