Linux:

1
Linux

• Getting Started

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Objectives

• This unit provides basic information about Linux
• After completing this unit, you should be able
  to
• Logon
• Execute basic tasks
• Describe the basic structure
• Edit files
• Manage the file system

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Contents

• 1 - Introduction.
• 2 - Login, work, logout.
• 3 - Structure file system, process.
• 4 - Commands.
• 5 - Editors.
• 6 - Compile and run a program.
• 7 - Finding help.

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1 - Introduction
5
Where to get more information...

• www.linux.org
• www.redhat.com

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What is Linux?

• Open Source Operating System.
• Freely distributed
• Based on Unix
• Being developed by programmers all over the
  world.
• Very popular Unix brand

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History

• 1991 - Linux is created as a hobby by a student
  at University of Helsinki (Finland)
• 1992 - First public version
• 1993 - First prefabricated Linux distributions
• 1996 - Support for non-Intel processors
• 1999 - Linux 2.2 released (the version currently
  in use)

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2 - Login, work, logout.
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How to login
10
What one sees after login...
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The desktop

• Several desktop environments available to Linux
  (Gnome and KDE among others).
• Xwindow compatible.
• Drag and drop capabilities.
• Easily customized.

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Open a new window...
13
How to logout
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3 - Linux Structure
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Unix Structure
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Shells

• Several shells available ksh,csh, bsh...
• Linux gt bash
• Shell Scripts

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standard input/output
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The Filesystem

• Notice the similarities with other OS.

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Permissions

• All directories are special files
• The read/write/execute scheme is used

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4 - Commands
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Command format

• ltcommandgt ltoptionsgt ltargumentsgt
• Examples
• ls -la /home/group1
• (this enables the user to see the file structure
  with dates etc)
• who
• (it shows who is logged in the same machine)
• ps -ef
• (it shows what processes are running specifically
  for this session)

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Command format

• Pipes and filters
• Pipes makes the output of the command to become
  the input for the next command
• Filters read from input and write to standard
  output
• command filter

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Command format

• examples
• ps -ef grep group1
• (this shows all processes related with userid
  group1)
• ps -ef grep group1 wc -l
• (this will count the number of processes related
  with group1)

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Basic Command...

• List files ls -la
• Mnemonic list

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Three important tips

• 1 - Double ltescapegt
• Get file or command names with a few characters
• 2 - Arrows
• Retrieve commands using ? or ?
• 3 - ctrl-C
• stop programs at once

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File commands

• ls -la shows all files
• mv ltname1gt ltname2gt to rename a file, move
• cp ltname1gt ltname2gt copy a file or directory

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File commands (cont.)

• rm ltnamegt remove a file or dir
• touch ltnamegt creates a zero size file
• more shows the file
• (like type in DOS)

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Examples ls, cp, mv
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Examples mv, touch
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Examples more
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Directory commands

• cd (change directory)
• mkdir (make directory)
• rmdir (remove directory)
• pwd (which directory?)

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cd, mkdir, rmdir
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Process

• ps -ef (shows all running process)

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Shells and Process
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5 - Editing files
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Open gEdit
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Graphical Editors

• There are several editors available. gEdit is an
  example

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Other editors.

• gxedit
• vim, gvim
• emacs
• joe
• jed
• etc..

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Print files

• lpr -Pltqueue namegt ltfile namegt
• Example print /etc/hosts
• lpr -Pbrother56 /etc/hosts

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Print files

• To query the queue manager
• lpq -Pltqueue namegt

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Print files
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6 - How to compile and run a test program
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Compile and run

• g77 ltfile namegt
• Creates a.out by default
• To run type a.out
• g77 ltfile namegt -o ltany-namegt
• Creates any-name executable
• To run type that name

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Compile and test.
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Compile and test (cont.).
46
7 - Finding help
47
man command

• man stands for manual
• available in most Unix brands
• man ltcommandgt

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man command

• To scroll forward and backward
• press space or page down to forward
• press b or page up to backward
• press q to quit

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man example

• man ls