RHCE I Essential book by Moamen Hany

RHCE
RHCE ~
Red Hat Certified Engineer
Administration I - Essential Book
Author :
Mo‟men Hany ©
2012 Copyright © March 2012 ,
Engineer Mo‟men Hany Mohamed

RH033 - Red Hat Linux Essentials
RHCE
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Welcome in
Copyright © March 2012 ,

By Eng Mo‟men Hany ©
RHCE
Contents
Copyright
Unit1:History For UNIX & LINUX
Unit2:Linux Environment
Unit3:Using The System
Unit4:Working with Files and Directories
Unit5:File and Directory Permissions
Unit6:Linux Documentation & Help
Unit7:Tour Through Linux
Unit8:Editing Files
Unit9:Shell Basic‟s
Unit10:Working with Processes
Unit11:Linux Utilities
Unit12:Shell Scripting
Unit13:Linux GUI
Unit14:Basic System Configuration Tool
Certification Information
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Copyright
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The contents of this book are copyright © March 2012 ,
Engineer Mo‟men Hany Mohamed.
Does not allow the amendment in this book , A free copy
of any one.
The Instructors also have the right to be assisted
in this book in their own explanations and labs.
Been used to create this book with Eng.M-Hany
Experience , IBM, red hat and general books.
Contact book owner : -
Mobil: (Egypt) +2 011 437 395 45
Email: IT.momenhany@hotmail.com
http://www.facebook.com/MomenHanyFP
By Eng Mo‟men Hany ©

By Eng Mo‟men Hany © Mobil: 01143739545 ^ Email: IT.momenhany@hotmail.com
RHCE
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Unit1:
History For UNIX & LINUX
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Module Overview
o What is O.S ?
o What is Kernel ?
o UNIX History ?
o LINUX History ?
o What about Red Hat ?
o Linux Distribution‟s .
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Operation System
An operating system is a program designed to run other
programs on a computer. A computer‟s operating system is its
most important program. It is considered the backbone of a
computer, managing both software and hardware resources.
Hardwar O.S
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Kernel
• kernel is the central core of operating system.
• it does not interact with user , rather it interact with shell as well as with
hardware devices.
http://www.kernel.org/
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UNIX History
Year Event
1957 Bell Labs found they needed an operating system for their computer center
that at the time was running various batch jobs. The BESYS operating
system was created at Bell Labs to deal with these needs.
1965 Bell Labs was adopting third generation computer equipment and decided
to join forces with General Electric and MIT to create Multics (Multiplexed
Information and Computing Service).
1969 Withdrawn Ken Thompson and Dennis Ritchie needed to rewrite an
operating system in order to play space travel on another smaller machine,
The result was a system that a punning colleague called UNICS (UNiplexed
Information and Computing Service)
1969 Summer 1969 Unix was developed.
1969 Linus Torvalds is born.
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UNIX History
Year Event
1971 First edition of Unix released 11/03/1971. The first edition of the "Unix
PROGRAMMER'S MANUAL [by] K. Thompson [and] D. M. Richard Stallman.
It includes over 60 commands like: b (compile B program); boot (reboot
system); cat (concatenate files); chdir (change working directory); chmod
(change access mode); chown (change owner); cp (copy file); ls (list
directory contents); mv (move or rename file); roff (run off text); wc (get
word count); who(who is one the system). The main thing missing was
pipes. (GNU Project)
1972-1975 Second to Sixth edition of Unix released.
1977 1BSD released late 1977.
1978 -1980 2-4BSD released mid.
1985 Eighth edition of Unix released February 1985.
---- More “SGI-Ultrix-HP-UX-Ninth-Sun-IBM For IAX-NetBSD -..”
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LINUX History
Year Event
1991 Linux is introduced by Linus Torvalds, a student in Finland.
That was Developed Linus to Support (Multi Tasking ) woooooo.
-- It was licensed under GNU General Public License(GPL), thus ensuring
that the source codes will be free for all to copy, study and to change.
Students and computer programmers grabbed it.
1994 Red Hat Linux is introduced.
----- Red Hat , Caldera, and some other companies gained substantial amount of
response from the users worldwide. While these were commercial ventures,
dedicated computer programmers created their very own volunteer-based
distribution, the famed Debian. With the new Graphical User
Interfaces (like X-window System, KDE, GNOME)the Linux
distributions became very popular.
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Red Hat
http://www.redhat.com/about/company/history.html
Best Company in the world introduced Linux Red Hat and Fedora O.S Dist.
That has Support and Training for Red hat products .
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Linux Distribution‟s
http://distrowatch.com/
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Unit2:
Linux Enveronment
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Module Overview
o Linux 4 User & Linux 4 Server‟s .
o File Structure .
o Shell Prompt .
o Disk & Partitioning .
o Install Red Hat Enterprise 6 .
*Master Boot Record (MBR)+Dual Boot.
o Window System “Desktop” .
o Virtual Consoles and Graphic Console .
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Client & Server Environment‟s
● Linux
Distribution‟s
are OS‟s based on the Linux kernel.
● Red Hat Enterprise Linux
• Stable, thoroughly tested software.
• Professional support services.
• Centralized management tools for large networks.
● The Fedora Project
• More, newer applications.
• Community supported (no official Red Hat support).
• For personal systems.
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File Structure
/
root home usr dev mnt etc var boot bin sbin opt
Admin
Home
Directory
User
Home
Directory
System
Executable
Files
Special
Files For
Devices
Other
Mount
Devices
Service
Config
Files
Variable
Files
Boot Files
“MBR”
User
Executable
Files
Admin
only
Executable
Files
Third
Party App
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Shell
Shell Name Ash Bourne Bash (Bourne
Again)
Korn C-shell T-shell Zsh
Author Kenneth
Almquist
Brian
Fox/Chet
Ramey
Eric Gisin William Joy Paul Falstad
Binary ash sh Bash ksh csh tcsh zsh
Default
Prompt
$ $ $ % %
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Disk & Partitioning
Primary v.s Extended
Linux File System
Partition Leased
SWAP Partition
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Installation
Go To Lab
Install Linux O.S Red Hat & Fedora :-
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Window System
Two desktop environments provided by Red Hat:
• GNOME: the default desktop environment.
• KDE: an alternate desktop environment.
Note:-
“A typical Linux system will run six virtual
consoles and one graphical console”
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Virtual Consoles and Graphic
Console
Switch among virtual consoles by typing: Ctrl-Alt-F[1-6]
Access the graphical console by typing: Ctrl-Alt-F7
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Unit3:
Using The System
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Module Overview
o Log in and out of the system.
o State the structure of Linux commands.
o Execute basic Linux commands.
o Change your password.
o Use the command history.
o Use the keyboard and mouse effectively.
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Log in and out of the system
Linux is Multi-user and Multitasking
Linux is a multi-user, multitasking operating system
Multiple users can run multiple tasks simultaneously, independent
of each other.
Always need to "log in" before using the system
Identify yourself with username, password
Multiple ways to log in to the system
• Console: Directly attached keyboard, mouse, monitor
• Serial terminal
• Network connection
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Log in and out of the system N P
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Log in and out of the system
Switching between virtual consoles and the graphical
environment
● A typical Linux system will run six virtual
consoles and one graphical console
• Server systems often have only virtual consoles
• Desktops and workstations typically have both
● Switch among virtual consoles by typing:
Ctrl-Alt-F[1-6]
● Access the graphical console by typing Ctrl-
Alt-F7
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State the structure of Linux commands
Command Prompt
Examples:
[user@host ~]$
[root@host ~]#
$
#
• The dollar ($) usually means: "logged in as regular user"
• The hash (#) usually means: "logged in as root"
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Linux Command Syntax
$ command option(s) argument(s)
$ ls just command
$ ls -l command and option
$ ls /dev command and argument
$ ls -l /dev command, option and argument
$ ls –I I node , index number of file
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RIGHT
1. Separation
$ mail -f personal
$ who -u
2. Order
$ mail -s test root
$ who -u
3. Multiple options
$ who -m -u
$ who –mu
WRONG
1. Separation
$ mail - f personal
$ who-u
2. Order
$ mail test root -s
$ -u who
3. Multiple options
$ who -m-u
$ who -m u
Command Format Examples
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Execute basic Linux commands
passwd: Change your password
mkpasswd: Generate a random password
date, cal: Find out today's date and displays a calendar
who, finger: Find out who else is active on the system
clear: Clear the screen
echo: Write a message to your own screen
write: Write a message to other screens
wall: Write a message to all screens
talk: Talk to other users on the system
mesg: Switch on/off reception of write, wall and talk messages
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The date Command
__________________
date shows the current date and time
$ date
Fri Jun 6 11:15:10 CET 2003
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The cal Command
________________
cal shows a calendar
Synopsis: cal [Month] [Year]
$ cal 6 2003
June 2003
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30
$
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Who Is on the System
_____________________
who shows who is logged onto the system
$ who
root tty1 Mar 5 11:10
User1 tty2 Mar 5 11:04
$ who am i
host!User1 tty2 Mar 5 11:04
But:
$ whoami
user1
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Finding Information about Users
_____________________________
The finger command shows info about other users
Synopsis: finger [user][@host]
$ finger
Login Name Tty Idle Login Time
User1 Tux (1) 2 Mar 5 11:04
root root *1 7 Mar 5 11:10
$ finger User1
Login: User1 Name: Tux (1)
Directory: /home/User1 Shell: /bin/bash
On since Fri Mar 5 11:04 (CET) on tty2
No mail.
No plan.
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The clear, echo, write, and wall Commands
_______________________________________
The clear command clears your screen
$ clear
The echo command writes messages to your own screen
$ echo Who wants to go to lunch?
Who wants to go to lunch?
Use write to display a text message on a user's terminal
$ write user2
Message
<ctrl-d>
Use wall to place a message on all logged in user's displays
$ wall
I'm back
<ctrl-d>
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Talk with Another User
_____________________
If Ahmed wants to talk with Momen, Ahmed enters:
$ talk Momen
If Momen also wants to talk with Ahmed, Momen enters:
$ talk Ahmed
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The mesg Command
The mesg command controls whether other users can send
messages to you with the write, wall or talk command or through
output redirection.
User User1 at user1:
$ mesg n
User User1 at User2:
$ write User1
User1 write: User1 has disabled messages on User1
$ mesg y
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• <backspace>, <ctrl-h>
• <ctrl-c>
• <ctrl-d>
• <ctrl-s>
• <ctrl-q>
• <ctrl-w>
• <ctrl-u>
• <tab>
• Corrects mistakes
• Terminates the current
command and returns to the shell
• End of transmission
• Temporarily stops output to the
screen
• Resumes output
• Erase last word
• Erase the entire line
• Command or filename
completion
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• <arrow up>
• <arrow down>
• <arrow left>
• <arrow right>
• <shift page-up>
• <shift page-down>
• <Ctrl-R>
• Previous command
• Next command
• One character to the left
• One character to the right
• Look at the output of previous
commands
• Look at the output of later
commands; eventually gets youback
to the command prompt
• Search for a command in
thecommand history
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Change your password
To change your password using GNOME,
navigate to System->Preferences->About Me
and then click Password.
● To change your password from a terminal:passwd
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Use the command history
Command History
_______________
Command history also can be viewed with history command
$ history 5
99 clear
999 wc .bash_profile
1000 history
$ !! Run last command
$ !-3 Run last 3 command
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Use the keyboard and mouse effectively
Go To Lab
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Unit4:
Working with Files and Directories
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Module Overview
o Describe the different file types
o Describe file and pathnames
o Create, delete, copy, move and list directories
o Create, delete, copy and move files
o View the content of both text and binary files
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Describe the different file types N P
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Describe the different file types
Linux Filenames
_______________
• Should be descriptive of the content
• Should use only alphanumeric characters:UPPERCASE, lowercase,
number, @, _
• Should not include embedded blanks
• Should not contain shell metacharacters:* ? > < / ; & ! [ ] | ' " ( ){}
• Should not begin with + or - sign
• Are case-sensitive
• Filenames starting with a . are hidden
• The maximum number of characters for a filename is 255
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Absolute and Relative Pathnames
______________________________
Absolute pathnames
• Begin with a forward slash “/”
• Complete "road map" to file location
• Can be used anytime you wish to specify a file name
Relative pathnames
• Do not begin with a slash
• Specify location relative to your current working directory
• Can be used as a shorter way to specify a file name
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Current Working Directory
_______________________
● Each shell and system process has a
current
working
directory (cwd)
● pwd
Displays the absolute path to the shell's cwd
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Create, delete, copy, move and list
directories
Change Current Directory
_________________________
With the cd (change directory) command:
$ cd dir_name
$ cd doc (relative)
$ cd /home/user1/doc (full& absolute)
$ cd ~user1/doc (home)
$ cd (Go to your home directory)
$ cd .. (Go one directory up)
$ cd - (Go to previous directory)
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directories
Listing Directory Contents
● Lists the contents of the current directory or a specified
directory
● Usage:
• ls [options] [files_or_dirs]
● Example:
• ls -a (include hidden files)
• ls -l (display extra information)
• ls -R (recurse through directories)
• ls -ld (directory and symlink information)
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directories
Working with Multiple Directories
_____________________________
Create and remove multiple directories simultaneously with the –p flag
$ mkdir -p dir1/dir2/dir3
$ rmdir -p dir1/dir2/dir3
$ rmdir doc test
rmdir: doc: Directory not
$
directory must be empty!
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Create, delete, copy and move
files
The touch Command
__________________
The touch command creates an empty file, or updates the
modification time of an existing file.
$ ls -l
-rw-rw-r-- 1 tux1 penguins 512 Feb 24 11:10 docs
$ touch docs
$ ls -l
-rw-rw-r-- 1 tux1 penguins 512 Mar 5 15:37 docs
$ touch new
$ ls -l
-rw-rw-r-- 1 tux1 penguins 512 Mar 5 15:37 docs
-rw-rw-r-- 1 tux1 penguins 0 Mar 5 15:37 new
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files
Remove File or Directory
__________________
$ rm dir
$ rm –p /dir1/dir2/dir3 Remove more Director's
$ rm –p dir1/dir2/dir3
$ rm –f dir1/dir2/dir3 Force Remove Dir If Empty or no
$ rm –p file1/dir4/file7/dir7
$ rmdir –r dir2 Remove Dire and sub Director's and Files
$ mkdir -p dir1/dir2/dir3
$ rmdir -p dir1/dir2/dir3
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files and Directory‟s
Copying Files and Directory's
__________________________
The cp command copies files and directory’s :
cp source[s] [target]
$ cp –r dir1 /home/user1/myfiles
$ cp –r .dir1 /home/user1/myfiles/momendir Copy Hidden Dir with new name
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files and Directory‟s
Moving Files and Directory's
_________________________
The mv command move files and directory’s:
. mv <source> <Destination>
$ mv file1 /home/user1
$ mv file1 dir1 /home/user1 Move multi file‟s and Dir
$ mv dir11 /home/user1/dir12 Move Dir with new name
_____________________________________________________
Hide File or Directory‟s
____________________
$ mv file1 .file1
$ mv dir4 .dir4
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files
File Link
________
File Link Type:
• Hard Link – you can store mirrored file in another location that
has every changed in the master file “File Synchronization”
“Foul tolerance”
• Sof Link – as short cut file
$ ln file1 /home/user1/file1 you can create with different name (Hard Link)
$ ln file1-s /home/user file1 (Soft Link)
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files
Show File Contents
_______________
$ cat File2
--------------------------------------------------------------------------------
File Details
_________
$ wc file1 show n of line , carachters , word’s
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View the content of both text and binary files
Displaying Files Page by Page
__________________________
With the more or less commands:
$ less File1
$ more File1
Displaying Binary Files
___________________
With the od command
$ od File1  Display File as Binary
$ od -c File1  Display File as Decimal
$ od –h File1  Display File as Hexadecimal
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Splitting File
Splitting Files
___________
You can split a file into a smaller files with the split command
split -b <Bytes> file [prefix]
$ Split –b 1024 File1 Filexs  Split File1 to more Files each spitted File is <1024>
Join Smaller Files into Large File
____________________________
$ cat filexsa filexsb filexsc >output file name
Or
$ cat filexs* >output file name
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Unit5:
File and Directory Permissions
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Module Overview
o Explain the Linux security model
o List the permissions required to perform several common
commands
o Change permissions using symbolic and octal notation
o Describe how default permissions are calculated
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Explain the Linux
security model
Access Level
Permission
User & Owner Group Other
-rw-r--r-- 1 user2 sales 171 Jun 4 10:23 file2
drwxr-xr-x 2 user1 hr 512 Jun 7 11:13 mydir
File
Type
Permi
-ssion
Link
Counter
Owner
Group
Size Modification
Time
Name
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Explain the Linux
security model
Permissions Notation
___________________
rwx rwx rwx
User group other
regular files:
r file is readable
w file is writeable
x file is executable ( if in an executable format )
directories:
r contents of directory can be listed (ls)
w contents can be modified (add/delete files)
x change into directory is possible (cd)
r read
w write
x execute
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List the permissions required to perform
several common commands
$ ls –l
-rw-r--r-- 1 user2 sales 171 Jun 4 10:23 file2
drwxr-xr-x 2 user1 hr 512 Jun 7 11:13 mydir
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Change permissions using symbolic and
octal notation
Assign Permission
Symbolic Method
Numeric & Octal
Method
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octal notation
Assign Permission by Symbolic Method:-
__________________________________
$ chmod ugo+rwx file1 Full control 4 user group and other
$ chmod a+rwx dir1 Full control 4 user group and other
$ chmod o-wx dir2  Deny permission write and execute to other
+ add permission
- Remove Permission
U = User & Owner
G = Group
O = Other
A = All <u+g+o>
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octal notation
User group other
r w x r w x r w x
4 2 1 4 2 1 4 2 1
------ ------- -------
7 7 7 =Full Control 4 (U+G+O)
R  22 = 4
W  21 = 2
X  20 = 1
-  0 = 0
---------------------
7
Example:-
$ chmod 764 file1
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Describe how default permissions are
calculated
Any New File
Or Directory
Crated by
default
Has default
permission from
System.
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calculated
Dir : 777 - 022 = 755 ( rwx rw- rw-)
Example:-
I need when create any new Directory the default permission is { rw- r– r--} (644)
Net permission – Full permission = umask
644 - 777 = 133
? UMASK is 133
$ umask 133
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calculated
Change UMASK using Symbolic Method:
______________________________________
$ umask u=rwx,g=rw,o=r  Set umask by symbolic
$ umask –S  Show Symbolic umask 4 all users
Note:
If Machine Restarted the umask change to default (022,002)
$ cat /etc/bashrc  edit umask in this file by root 4 force umask
constant on all users
umask 022
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Unit6:
Linux Documentation & Help
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Module Overview
o Describe the use of man
o Describe the use of info
o Describe the use of whatis
o Describe the use of help
o Describe the documentation Location
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Describe the use of man
The man Command
_________________
With the man command you can read the manual page of
commands.
Manual pages are stored in /usr/share/man
The manual page consists of:
Name The name of the command and a one-line description
Synopsis The syntax of the command
Description Explanation of how the command works and what it does
Options An explanation of the options
Files The files used by the command
Bugs Known bugs and errors
See also Other commands related to this one
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$ man finger
NAME
finger - user information lookup program
SYNOPSIS
finger [-lmsp] [user ...] [user@host]
DESCRIPTION
The finger command displays information
about the system users.
Options are:
-s Finger displays the user's login name,: :
The -k option of the man command or the apropos command
prints
out a description of all entries which match the given keyword
$ man –k print
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Manual pages are divided in 9 sections:
_________________________________
1. User commands
2. System calls
3. Libc calls
4. Devices
5. File formats and protocols
6. Games
7. Conventions, macro packages and so forth
8. System administration
9. Kernel
Certain subjects appear in multiple sections
To select correct section, add section number:
man 1 passwd (about the passwd command)
man 5 passwd (about the passwd file)
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$ man –a passwd  Show command Section page by page
$ man –w passwd  Command File Path
$ man –k list  search about <list> in entire manual
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Describe the use of Info
The info Command
______________________
Sometimes a replacement for manual pages
Widely used by the GNU project
Information for info is stored in /usr/share/info
Some info commands:
space next screen of text
del or bs previous screen of text
n next node
p previous node
q quit info
/ or s search about word
$ info pwd
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Describe the use of help
The --help Option
________________
Another way of getting help about a command
Help is built in the command itself (if supported)
$ who --help
Usage: who [OPTION]... [ FILE | ARG1 ARG2 ]
-h, --heading print line of column headings
-m only hostname and user
associated with stdin
-q, --count all login names and number of
users logged in
--help display this help and exit
--version output version information and exit
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Describe the use of whatis
The whatis Option
________________
Another way of getting help about a command
$ whatis pwd
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Describe the documentation
Location
Usually stored in
/usr/share/doc/<programname>
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Unit7:
Tour Through Linux
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Module Overview
o Describe the structure of the filesystem
o Mount and unmount Devices
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Describe the structure of the
filesystem
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filesystem
/bin, /lib, /sbin
____________
• /bin contains executables for every user
• /sbin contains system administration executables
• /lib contains libraries
• Should always be available
 At system boot
 In single user mode
 When booting from rescue disk
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filesystem
/Boot
_____
The /boot directory contains the kernel images, some other things
related to these images
and the files needed for the bootloader (LILO or GRUB).
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filesystem
/dev
____
Contains special files that represent hardware devices
Block special device, for example, a hard disk
Character special device, for example, mouse and
keyboard
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filesystem
/etc
___
• Contains system-wide configuration files
• Some subsystems have multiple files and therefore use a separate directory
/etc/X11 contains X Window System configuration
/etc/skel contains default user configuration files
/etc/sysconfig contains system configuration
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filesystem
/home
_____
Home directories of users
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filesystem
/mnt
____
Mount points for other filesystems
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filesystem
/proc
_____
• Virtual filesystem
• Represents kernel and process information
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filesystem
/root
____
Home directory of the root user
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filesystem
/tmp
____
• Temporary storage space for programs, users
• Usually automatic cleanup mechanism active
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filesystem
/usr
___
• UNIX System Resources
• Contains all programs, libraries and so on which are not
• essential for system boot and emergency operations
/usr/local intended for programs not in the distribution
Locally developed
Locally compiled
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filesystem
/var
____
• Files of variable size
Logfiles
Lockfiles
• Directories with variable content
Mail
Scheduling
Printing
• Temporary storage space, longer than /tmp
N P
F
L

filesystem
/lost+found
__________
• Exists in every filesystem
• Place where lost+found files are stored after a crash recovery by fsck.
N P
F
L

filesystem
Other Directories in /
____________________
• /opt: used for some software from external providers
Separate filesystem advisable
• Whatever you create yourself.
N P
F
L

Mount and unmount Devices
The mount Command
____________________
The mount command mounts a filesystem
Makes it part of the unified filesystem structure
mount [-t type] [-o opts] device mountpnt
$ mount /dev/hda5 /usr
N P
F
L

The umount Command
_____________________
The umount command unmounts a filesystem
Takes it out of the unified filesystem structure
Filesystem should not be busy
umount {device|mountpnt}
$ umount /dev/hda5
- OR -
$ umount /usr
N P
F
L

The /etc/fstab File
_________________
• /etc/fstab lists all known filesystems on the system
N P
F
L

Unit8:
Editing Files
N P
F
L

Module Overview
o Determine the type of file using file
o Edit text files with vi
o Discuss other text file editors such as kedit
N P
F
L

Determine the type of file using file
Editing Files
__________
Use file command to determine the content of a file
To edit text files, use an editor
Non-text files can only be changed using the application
that created them, or with a hex editor
But most configuration files under Linux are text files
$ file /etc/passwd
N P
F
L

Edit text files with vi
The vi text editor
______________
• Default editor in all UNIX operating systems
• Usually the only editor available in emergencies
• Relatively hard to learn, but really powerful
• As a Linux user, you should be able to use vi for basic editing tasks
-But it's OK if you prefer another editor for daily work
• vi in Linux is usually vim (vi improved):
• Syntax highlighting
• Arrow keys, Del, BS work in insert mode
• Multi level undo
• Mouse support
N P
F
L

vi Modes
vi knows three modes of operation
Command mode (for simple, one-letter commands)
Edit mode (insert text)
ex mode (for complicated commands)
Can easily change between modes
N P
F
L

$ vi myfile.txt
Cursor Movement in Command Mode
_________________________________
N P
F
L

Editing Text in Command Mode
____________________________
To delete a single character under cursor x
To delete a single character left of cursor X
To replace a single character r
Undo the last change u
To repeat last command .
To join two lines together J
N P
F
L

Switching to Edit Mode
____________________
• To insert text at begin of line I
• To insert text before cursor i
• To append text after cursor a
• To append text at end of line A
• To go back to command mode <ESC>
N P
F
L

Searching for mhany
___________________
To search for a pattern (in command mode): /<mhany>
Replacing Patterns
_________________
Advanced search and replace can be done in ex mode:
To replace old with new: :1,$s /old/new/g
N P
F
L

Cut, Copy and Paste
___________________
• To cut a whole line into buffer: dd
• To copy a whole line into buffer: yy
• To paste contents of buffers here: p
• To cut, copy multiple lines, proceed command by number: 3dd, 8yy
Exiting vi__
• To save and exit in command mode ZZ
• To save in ex mode :w
• To forcefully save file in ex mode :w!
• To quit without saving in ex mode :q
• To forcefully exit in ex mode :q!
• To save and exit in ex mode (recommended) :wq
• To save and exit in ex mode, shorter :x
N P
F
L

Edit text files with vi N P
F
L

Other Editors
___________
A typical Linux distribution comes with a large number of editors.
Examples:
Text mode editors
pico (really simple)
Original vi
emacs (even more powerful and complicated than vi)
Graphical mode editors
kedit, kwrite
gedit
Hex editors allow you to change non-text files if you know the
internal structure
khexedit
N P
F
L

Unit9:
Shell Basics
N P
F
L

Module Overview
o Explain the function of the shell
o Discuss metacharacters and reserved words
o Use wildcards to access files with similar names
o Use redirection and pipes
o Use command substitution
o Work with shell variables
o Use aliases
o Create Scripts
N P
F
L

Explain the function of the shell
The Shell
The "shell" is the user interface to Linux
N P
F
L

Discuss metacharacters and
reserved words
Metacharacters and Reserved Words
Metacharacters are characters that the shell interprets as having a
special meaning.
Reserved words are words that the shell interprets as special
commands.
Examples:
< > | ; ! ? * [ ] $ " ' ` ~ ( ) { }
Examples:
case do done elif else esac fi for function if in select then
until while
N P
F
L

Use wildcards to access files
with similar names
$ echo *[1-5]  get all file that have no – 1 to 5
test1 test2
$ echo [!t]*  get all files exception have (t)
Myfile
$ echo ?[!y]*[2-5]  non have (y) but have 2 to 5
test2 test1
N P
F
L

Use redirection and pipes
File Descriptors
• Every program has a number of file
descriptors associated with it
• Three descriptors are assigned by the shell
when the program starts (STDIN,
STDOUT and STDERR)
• Other descriptors are assigned by the
program when it opens files
N P
F
L

Input Redirection
STDIN redirected from file:
$ cat < file1
Hi
Welcome
Etc
N P
F
L

Output Redirection
$ ls > fileb
$ cat > new_filex
Save this line
<Ctrl-D>
N P
F
L

Error Redirection
$ ls-l 2> errorfile
$ cat errorfile
Ls-l command not found
----------------------------------------------------------------
Redirect and append errors to a file:
$ cat-a 2>> errorfile
N P
F
L

Pipes
A sequence of two or more commands separated by a
vertical bar (|) is called a pipe or pipeline
$ ls –l | wc -l
N P
F
L

Common Filters
expand, unexpand: Change tabs to spaces and vice versa
sed: Allows string substitutions
awk: Pattern scanning and processing
fmt: Insert line wraps so text looks pretty
tac: Display lines in reverse order
tr: Substitute characters
grep: Only displays lines that match a pattern
nl: Number lines
pr: Format for printer
sort: Sort the lines in the file
$ tr filea
N P
F
L

Split Output
The tee command reads standard input and sends the
data to both standard out and a file.
$ ls | tee ls1.save | wc -l
3
$ cat ls1.save
file1
file2
file3
N P
F
L

Use command substitution
Command Substitution
Command Substitution allows you to use the output of a command
as arguments for another command.
$ echo there are $(cat filea | wc –l)
N P
F
L

Use command substitution
Command Grouping
Multiple commands can be entered on the same line,
separated by a semicolon (;)
$ echo my date is ; date ; cat filea ; ls
$ date ; pwd
N P
F
L

Work with shell variables
Shell Variables
Variables are part of the environment of a process A variable has an unique name The
first character must not be a digit
To assign a value to a variable use:
variable=value
$ VAR1=“Welcome in Linux“
$ echo $VAR1
Welcome in Linux
$ VAR2=50
$ echo $VAR2
50
N P
F
L

$ x=6
$ echo „my number is $x‟
My number is $x
$ echo “my number is $x”
My number is 6
N P
F
L

Standard Shell Variables
The shell uses several shell variables internally
These variables are always written in uppercase
Example:
$: PID of current shell
PATH: Path which is searched for executable’s
PS1: Primary shell prompt
PS2: Secondary shell prompt
PWD: Current working directory
HOME: Home directory of user
LANG: Language of user
N P
F
L

Return Codes from Commands
A command returns a value to the parent process. By convention, zero means
success and a non-zero value means an error occurred.
A pipeline returns a single value to its parent
The environment variable ? contains the return code of the previous command.
$ ls
Fiel1 file2 dir1 dir2
$ echo $?
0
$ cat fileab
cat: filea: No such file or directory
$ echo $?
1
N P
F
L

Use aliases
Aliases
The alias command allows you to set up aliases for often-used commands
Examples:
$ alias ll='ls -l'
$ alias rm='rm -i'
To show all currently defined aliases:
$ alias
To delete an alias:
$ unalias ll
$ ll
bash: ll: command not found
N P
F
L

Create Scripts
$ vi momenscript
>ls
>date
:wq
---------------------------------------------------------------------------------
$ chmod 700 momenscript
$ ls –l
momenscript
$ bash momenscript
$ source momenscript
$ sh momenscript
$ . momenscript
N P
F
L

Unit10:
Working with Processes
N P
F
L

Module Overview
o Define a Linux process
o Describe the relationship between parent and child processes
o Explain the purpose of a shell
o Start foreground and background processes
o Explain the concept of signals and use them to terminate
processes
o Manage processes using GUI
N P
F
L

Define a Linux process
What Is a Process?
• A program is an executable file
• A process is a program which is being executed
• Each process has its own environment:
To see the PID of your current shell process type:
$ echo $$
N P
F
L

Describe the relationship between
parent and child processes
All processes are started by other processes
Parent/Child relationship
$ ls -l
A process can be terminated because of two reasons:
• The process terminates itself when done
• The process is terminated by a signal from another process
N P
F
L

Monitoring Processes
The ps command displays process status information
ps supports a large number of options - you typically use ps aux:
• a all processes attached to a terminal
• x all other processes
• u provides more columns
N P
F
L

Viewing Process Hierarchy
pstree shows process hierarchy
Or
$ top
N P
F
L

Start foreground and
background processes
Starting
Processes
Foreground
Processes
Background
Processes
N P
F
L

Start foreground and
background processes
Foreground Processes
$ find / -name README
Foreground processes are invoked by simply typing a command at
the command line.
Background Processes
$ find / -name README &
Background processes are invoked by putting an "&" at
the end of the command line.
N P
F
L

Explain the concept of signals and use
them to terminate processes
Job Control in the Bash Shell
<ctrl-z> suspends foreground task
jobs lists background or suspended jobs
fg resume suspended task in the foreground
bg resume suspended task in the background
N P
F
L

Kill Signals
Several signals can be sent to a process
Using keyboard interrupts (if foreground process) $ kill -9 5698
Using the kill command
Synopsis: kill -signal PID
Using the killall command to kill all named apps
Synopsis: killall -signal application
N P
F
L

Running Long Processes
The nohup command stops a process from being killed if you
log off the system before it completes, by intercepting and
ignoring the SIGHUP and SIGQUIT (hangup and quit) signals.
$ nohup ls –l  Run command
$ logout  Logout from system
 Login  login to system
$ cat nohup.out  if you need to show last run command result
N P
F
L

N P
F
L

The nice Command
The nice command is used to start a process with a user
defined priority
nice [-n <value>] <original command>
$ nice –n 11 ls –l  Run (ls –l)command with priority <11>
N P
F
L

The renice Command
The renice command is used to change the priority of a
currently running process
renice <new_priority> <PID>
$ renice 7 6593  Change pritority value 4 PID 6593 to <7>
N P
F
L

Manage processes using
GUI
N P
F
L

Unit11:
Linux Utilities
N P
F
L

Module Overview
o Use the find and locate command to search for files
o Use the cut command to list specific columns of a file
o Use the grep command to search text files for patterns
o Use the head and tail commands to view specific lines in a file
o Use the sort command to sort the contents of a file
o Use the type, which and whereis commands to find commands
o Use the file command to find out the content of a file
o Use the join commands to combine files
o Comprise the files
N P
F
L

The find Command
$ find path expression
N P
F
L

The find Command
$ find . -name phone  Search about phone in current directory
$ find . -name phone –print  Search and print path
$ find . -name 'b*' -exec ls -i {} ;  search any file have (B) and execute as ls -l
$ find . -name b* -ok rm {} ;  search any file have (B) and remove file by file
$ find . -name b* -exec rm {} ;  search any file have (B) and remove all file
$ find . -perm 764  Search by permision 764
$ find . -name 's*' -type f -a -size +2  Search by size +2 k
locate Command
locate allows you to quickly find a file on the system, based on
simple criteria
$ updatedb
$ locate README
N P
F
L

The Cut Command
The cut Command
Pull selected columns or fields from one or more files.
Syntax:
cut -f(ields) -d(elimiter) file(s)
cut -c(haracters) file(s)
$ cut –f 1,3,4,7,9 –d: /etc/passwd
$ cut –f 1-18 –d /etc/passwd > outputfile
$ cat outputfile
N P
F
L

The grep Command
The grep Command
Searches one or more files or standard input for lines matching pattern
Simple match or Regular Expression
Syntax
grep [options] pattern [file1 ...]
$ grep root /etc/passwd  get number of (root) word in etc/passwd file
Option‟s:
-c “root$”  get but root must existing in last line
-c “root^”  get but root must existing in first line
N P
F
L

The grep Command
The grep Command
$ fgrep  Faster can‟t use Metacharacters (* / -)
$ egrep  search about more than word‟s in file such as < $
grep „test1 ; phone „
$ zgrep  Search in Compressed file (file.tar.gz or file.bz2)
Note:-
You can search about paragraph in file by „paragraph‟
N P
F
L

N P
F
L
The head and tail Commands
The head command can be used to view the first few lines of a file
or files. The command syntax is:
$ head [-lines] file(s)
$ head -4 /etc/passwd  Show only first 4 lines in passwd file
---------------------------------------------------------------------------
The tail command displays the last few lines of a file or files. The
command syntax is:
$ tail [{-lines|+lines|}] file(s)
$ tail -4 /etc/passwd  Show only last 4 lines in passwd file
$ tail -4 | head -4
The head and tail Command

N P
F
L
The Sort Command
The Sort Command
The sort command sorts the lines in the file specified and writes the result to
standard output.
$ sort /etc/passwd  Sort file from A-Z
$ sort –n /etc/passwd  Sort file by number from 1-9
$ sort –r /etc/passwd  Sort file by reverse viewer

N P
F
L
The type, which and whereis commands
The type, which and whereis Commands
To find out what the path to a command is, use type
$ type ls date echo
---------------------------------------------------------------------------------------------
To find out where the binary is located, use which
$ which ls date echo
---------------------------------------------------------------------------------------------
To locate the binary, source and manual page files of a command, use whereis
$ whereis ls date echo

N P
F
L
The file Command
The file Command
With the file command, you can find out what the type of data in the file is.
$ file /etc/passwd
$ file /lib/cpp

N P
F
L
The join command
The Join Command
The join and paste commands allow you to merge files together.
(1)
$ vi one
A xxx
B xxx
C xxx
:wq
(2)
$ vi two
A yyy
B yyy
C yyy
:wq

N P
F
L
The join commands
(3)
$ join one two
A xxx yyy
B xxx yyy
C xxx yyy
--------------------------------------------------------------------------------------
Output this value
$ join one two > mergedfile

N P
F
L
Compress The File
The gzip, gunzip and zcat Commands
To compress or uncompress files use gzip, gunzip or zcat
$ gzip fileneme  Compress File
$ gunzip filename  Un Compress file
$ zcat file.gz  Show compressed file
$ zgrep file.gz
$ zless file.gz
$ zmore file.gz

Unit12:
Shell Scripts
N P
F
L

Module Overview
o Create a Scripts
N P
F
L

Unit13:
Linux GUI
N P
F
L

Module Overview
o Components of the X Window System
o The function of the X Server
o The main characteristics of Desktop Environments
o Switch between GNOME and KDE
N P
F
L

N P
F
L
The Linux Graphical User Interface
• The "X Window System" is the GUI of Linux
• Developed at MIT in 1984
• Current standards body: X Consortium Shortname: X ( XI Graphic &
Xfree Graphic)
X uses client-server model with network connections
• Highly flexible
• Easy exchange of components
• Supports networked applications and sessions, independent of
• the OS
Components of the X Window System

N P
F
L
The function of the X Server

N P
F
L
X Components
An X Server
• Controls keyboard, mouse and one or more screens
• Controls resolution, refresh rate and color depth
• Allows simultaneous access by several clients
• Performs basic graphic operations
• Forwards keyboard and mouse events to the correct clients
An X Client
• Is for instance an application
• Receives keyboard and mouse inputs from server
• Sends output to be displayed to server
A Window Manager
• Is a special X Client
• Performs "windows dressing" on other clients
• Allows other client windows to be moved, iconified and so forth
Components of the X Window System

N P
F
L
XFree86 Configuration
XFree86 needs to be configured for your hardware
Keyboard
Mouse
Graphical adapter
Monitor
Things to configure: refresh rate, resolution, color depth
Config file: /etc/X11/XF86Config
X

N P
F
L
X Servers in Linux
Most distributions use XFree86 (www.xfree86.org) as their X Server
• Open Source
• Supports most video adapters
Other X Servers for Linux are available as well
• Metro-X (http://www.metrolink.com)
• Xi Graphics (http://www.xig.com)
X

N P
F
L
Desktop Environments
Examples:
• GNOME (GNU Network Object Model Environment)
• KDE (K Desktop Environment)
The main characteristics of
Desktop Environments

N P
F
L
Switch between GNOME and KDE

Unit14:
Basic System Configuration Tool
N P
F
L

Module Overview
o List the order of login scripts
o Discuss System Management tools
o Install and uninstall additional software
o Configure a printer
o Configure a Network and sound card
N P
F
L

N P
F
L
List the order of login scripts
Customizing User Environment
Bash Initialization
/etc/profile  Contain system administrator processes
$ HOME/.bash_profile  Contain User processes
$ HOME/.bash_login  Contain Login User Configuration
$ HOME/.profile
$ HOME/.bash_logout  Contain Logout User Configuration
$ HOME/.bash_history  Save all Command history.
$ HOME/.bashrc  Contain Alias Command
# cat .bash_history

N P
F
L
Discuss System Management tools
List setup command (TUI Tool)
# setup
List system-config-<tab> command (GUI Tool)
# system-config-<press tab>
GUI  System Administration

N P
F
L
Install and uninstall additional software
Adding/Removing Software Using RPM
Use rpm to install or upgrade software packages
Common options:
-i : installing new packages
-U : upgrading existing packages
-e : removing packages
-h : Shows a progress bar
$ rpm -ihv momenpro.i386.rpm
momenpro ###############....
$ rpm -Uhv momenpro.i386.rpm
momenpro ###############.....
$ rpm -e momenpro
RPM
Red hat Package Management

N P
F
L
You can Donwload any RPM pachage using Linux Tools such as , wget :
# wget <download link>
#wget http://www.download.org/rpmpackages/webmin.rpm
30% Webmin.rpm ###############.... 70kbp/s Total Size 16MB
Use rpm Command
# rpm –i packagename
# rpm –ivh packagename  install package with show information and progress
# rpm –Uvh Packagename  upgradeing with show info and progress
# rpm –q packagename  Quarry about packagename

N P
F
L
Install tar package and compressed file:
# tar –zxf packagename.tar.gz
 ( z ) for gzip
 ( x ) for tar package extension
 ( f ) for file

N P
F
L
X
Install and access webmin
To access webmin interface
http://localhost.localdomain:10000

N P
F
L
Configure a printer
To access Printer Manager Console
http://localhost:631
Add New Printer ?
Add New Class ?
Manage Permission ?
….

N P
F
L
Configure a Network and
Sound card
Configure Network Card :
# ifconfig  for show ethernet configuration in tur
# neat  for show ethernet configuration in GUI
# ifconfig eth0  select and edite in eth0
# system-config-network -()()()()()()-

N P
F
L
Configure a Network and
Sound card
Configure Sound card :
# system-config-soundcard
-GUI System Administration Sound card detection

N P
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• The Red Hat (http://www.redhat.com) is the distributor of Red Hat Linux,
one of the leading commercial Linux distributions. As part of their service
organization they have developed their own education leading to the Red
Hat Certified Technician and Red
• Hat Certified Engineer exams. In contrast to the other Linux exams, the
RHCT and RHCE exams are performance based, which means that the
examinee takes place behind an actual Red Hat Linux system and needs to
demonstrate his/her skills on this system. The practical components of the
RHCT exam takes about 2.5 hours, while the practical components of the
RHCE exam take about five hours.
----------------------------------------------------------------------------------------
• Linux Professional Institute (http://www.lpi.org) is an organization run by
volunteers with the sole purpose of implementing a vendor-neutral
certification program for Linux. They are sponsored by a number of Linux-
related companies, among which IBM. The certification tests are delivered
by VUE (Virtual University Enterprises) (http://www.vue.comLPI aims to
implement three levels of certification, of which the first two levels are
currently ready.

N P
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 UnitedLinux (the consortium of Linux distributors SUSE, SCO,
TurboLinux and Conectiva, http://www.unitedlinux.com) has announced a
UnitedLinux certification, which will be an extension of the LPI
certification.
-----------------------------------------------------------------------------------------------
• CompTIA (http://www.comptia.org) is the organization that has, in the past,
already developed a number of certifications that are aimed mostly at
helpdesk personnel and hardware engineers. Recently CompTIA introduced
the Linux+ exam, which is aimed at Linux Professionals with 6 months of
experience with Linux. CompTIA tests are also delivered by VUE, and by
Prometric (http://www.prometric.com).

N P
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The LX02 (Linux Power User) is the entry course in the IBM/Linux curriculum. Its
aim is to teach a Linux novice to install and configure Linux so that he/she is able to
run Linux on
his/her personal workstation or home system in an environment that is mostly based
on MS-Windows.
The LX03 (Linux System Administration I: Implementation) is the main system
administration course. Its aim is to teach a Linux user the techniques and practices
used in installing, configuring, running and maintaining a Linux-based server.
The LX07 (Linux Network Administration I: TCP/IP and TCP/IP Services) is the
main
network administration course. Its aim is to teach a Linux system administrator how
to configure TCP/IP and various TCP/IP services that run on Linux.
The LX22 (Linux Perl Programming) is the course that covers Perl programming.
The LX23 (Linux Bash Programming) is the course that covers Bash shell
programming and the various programs that are typically used in shell programs,
such as grep, awk and sed.

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The LX24 (Linux Network Administration II: Network Security and Firewalls)
covers the configuration of a full-function firewall under Linux. As such, it also
covers a number of
security aspects of Linux that are not particularly related to firewalls, but apply to
any networked system.
The LX25 (Linux as a Web server - Apache) is the course which covers Apache,
the most commonly used Web server on Linux and other UNIX platforms.
The LX26 (Linux integration with Windows - Samba) is the course which covers
Samba, the product which emulates a networked Windows NT server to the network.

N P
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