1. Linux basic commands
Linux Basic Commands
Linux operating system has a beautiful graphical interface which most of us will be using. It
will be good to learn the basic commands in Linux to work interactively with the Linux
operating system. Linux has a back end access know as shell. You can control and activate all
the process in Linux from the shell. So it is very important to learn few basic commands to
work with Linux operating system.
First we will learn how to login for shell access. There are 7 terminals for Linux. 6 terminals
are non - GUI and 1 terminal for GUI access. You can login to each terminal using Alt + Ctrl +
F1 , F2, .. F7. Each terminals will request your username and password for login. If you want
to use the shell in the graphical interface (GUI), press Alt + F2 and type "konsole". As a user
you will have permission to access only your /home/user directory and other directories in it.
*Note: user denotes the username.
Basic commands in Linux
Navigation Commands - [ pwd, cd ]
pwd
This command is used to find the current location or current working directory.
Eg:
[user@ws26 ~]$ pwd
/home/user
cd
This command id used to change the directory. You can move from one directory to another using
this command. Few examples are given below.
Concider you have a directory structure /home/user/test/test1/ . test and test1 are directories in
user home.
Example 1:
Consider you have a directory "test" in /home/user. Your current working directory is /home/user.
You want to change your current working directory from /home/user to /home/user/test, use the
following command
[user@ws26 ~]$ pwd
/home/user
[user@ws26 ~]$ cd test
[user@ws26 ~]$ pwd
/home/user/test
Example 2:
If you want to move back to /home/user, use the following command
[user@ws26 ~]$ cd ..
[user@ws26 ~]$ pwd
/home/user

2. Example 3:
To get back to the home directory of the user
[user@ws26 ~]$ cd ~
[user@ws26 ~]$ pwd
/home/user.
Listing contents in a directory - [ ls, ls -l, ll ]
ls
This command is used to list all the files and directory in the current directory.
Eg:
[user@ws26 ~]$ ls
1152696870.jpg book OperaDownloads snapshot52.png
image300.jpg Desktop test spiderman2.jpg
ls -l or ll
This command is also used to list all the files and directories. Here you will get more details about
the files and directories present in the current directory. You will see the permission set, creation
date, file / directory size etc.
Eg:
[user@ws26 ~]$ ls -l
total 5
-rw-rw-r-- 1 user user 33188 Dec 22 02:56 1152696870.jpg
-rw-rw-r-- 1 user user 17647 Aug 19 2006 534458.gif
-rw-rw-r-- 1 user user 26817 Aug 19 2006 534477.gif
drwxrwxr-x 2 user user 4096 Jan 13 04:20 book
drwx------ 3 user user 4096 Feb 4 02:34 Desktop
Reading files in Linux - [ cat, more, less ]
Cat
This command is used to display the contents of a file. You can read the file contents using the cat
command.
Example:
[user@ws26 ~]$ cat testfile
this is a test file.. You can read me..
Less and More
Both the less and more commands serve similar function. They are used to display file one screen
at a time. You can press spacebar to continue reading the file. These commands are mainly used
while reading large files.
Example 1:
[user@ws26 ~]$ less testfile
this is a test file.. You can read me..
Example 2:
[user@ws26 ~]$ more testfile
this is a test file.. You can read me..

3. Manipulating files - [ cp, mv, rm, mkdir ]
cp
This command is used to copy files/directory.
Example:
[user@ws26 ~]$ cp file1 directory1
This will copy the file1 into the directory1
cp -R
This command is used to copy directories recursively (copy all the files and folders inside the
directory).
Example:
[user@ws26 ~]$ cp directory2 directory1
This will copy the whole directory2 into directory1
mv
This command is used to move the file or directory.
Example:
[user@ws26 ~]$ mv directory2 directory1
This will move the whole directory2 into directory1
rm
This command is used to remove or delete files and directories.
Example:
[user@ws26 ~]$ rm directory2
This will delete the directory - directory2
mkdir
This command is used to create a new directory
Example:
[user@ws26 ~]$ mkdir directory3
This will create a new directory - directory3.
create new file in Linux - vi editor
The Vi editor is mainly used to create new files in Linux.
Example:
vi testfile
The command will open a new window and you can insert text to it. To begin press "i". After adding
your contect press ":wq" to save the file.
anacron - runs commands periodically
anacron - A cron-like program that can run jobs lost during downtime.

4. arch - print machine architecture
at - queue, examine or delete jobs for later execution
at - execute commands at a later time
at - Job spooling tools.
at-spi - Assistive Technology Service Provider Interface
at.allow [at] - determine who can submit jobs via at or batch
at.deny [at] - determine who can submit jobs via at or batch
atd - run jobs queued for later execution
atq - queue, examine or delete jobs for later execution
atrm - queue, examine or delete jobs for later execution
arp - manipulate the system ARP cache
cal (1) - displays a calendar
cal (1p) - print a calendar
cat (1) - concatenate files and print on the standard output
cat (1p) - concatenate and print files
cdrecord (1) - record audio or data Compact Disks or Digital Versatile Disks from a master
cdrecord (rpm) - A command line CD/DVD recording program.
chage (1) - change user password expiry information
chattr (1) - change file attributes on a Linux second extended file system
chfn (1) - change your finger information
chgrp (1) - change group ownership
chgrp (1p) - change the file group ownership
chkconfig (8) - updates and queries runlevel information for system services
chkconfig (rpm) - A system tool for maintaining the /etc/rc*.d hierarchy.
chmod (1) - change file access permissions
chmod (1p) - change the file modes
chmod (2) - change permissions of a file
chmod (3p) - change mode of a file
chown (1) - change file owner and group
chown (1p) - change the file ownership
chown (2) - change ownership of a file
chown (3p) - change owner and group of a file
chpasswd (8) - update passwords in batch mode
chroot (1) - run command or interactive shell with special root directory
chroot (2) - change root directory

5. chrt (1) - manipulate real-time attributes of a process
chsh (1) - change your login shell
chvt (1) - change foreground virtual terminal
cksum (1) - checksum and count the bytes in a file
cksum (1p) - write file checksums and sizes
clear (1) - clear the terminal screen
cmp (1) - compare two files
cmp (1p) - compare two files
col (1) - filter reverse line feeds from input
colcrt (1) - filter nroff output for CRT previewing
colrm (1) - remove columns from a file
column (1) - columnate lists
comm (1) - compare two sorted files line by line
comm (1p) - select or reject lines common to two files
Compress::Zlib (3pm) - Interface to zlib compression library
cp (1) - copy files and directories
cp (1p) - copy files
cpio (1) - copy files to and from archives
cpio (rpm) - A GNU archiving program.
cpio.h [cpio] (0p) - cpio archive values
cpp (1) - The C Preprocessor
cpp (rpm) - The C Preprocessor.
crontab (1) - maintain crontab files for individual users (ISC Cron V4.1)
crontab (1p) - schedule periodic background work
crontab (5) - tables for driving cron (ISC Cron V4.1)
csplit (1) - split a file into sections determined by context lines
csplit (1p) - split files based on context
ctags (1p) - create a tags file (DEVELOPMENT, FORTRAN)
cupsd (8) - common unix printing system daemon
cupsd.conf [cupsd] (5) - server configuration file for cups
cut (1) - remove sections from each line of files
cut (1p) - cut out selected fields of each line of a file

6. Index - D
date (1) - print or set the system date and time
date (1p) - write the date and time
dd (1) - convert and copy a file
dd (1p) - convert and copy a file
deallocvt (1) - deallocate unused virtual consoles
debugfs (8) - ext2/ext3 file system debugger
depmod (8) - program to generate modules.dep and map files
depmod.conf [depmod] (5) - Configuration file/directory for depmod
depmod.d [depmod] (5) - Configuration file/directory for depmod
devdump [isoinfo] (8) - Utility programs for dumping and verifying iso9660 images
df (1) - report file system disk space usage
df (1p) - report free disk space
diff (1) - find differences between two files
diff (1p) - compare two files
diff-jars (1) - output the differences between two JAR files
diff3 (1) - find differences between three files
dig (1) - DNS lookup utility
dir (1) - list directory contents
dircolors (1) - color setup for ls
dirname (1) - strip non-directory suffix from file name
dirname (1p) - return the directory portion of a pathname
dirname (3p) - report the parent directory name of a file pathname
dirname [basename] (3) - Parse pathname components
dmesg (8) - print or control the kernel ring buffer
dnsdomainname [hostname] (1) - show the system's DNS domain name
doexec (1) - run an executable with an arbitrary argv[0]
domainname [hostname] (1) - show or set the system's NIS/YP domain name
dosfsck (8) - check and repair MS-DOS file systems
du (1) - estimate file space usage
du (1p) - estimate file space usage
dump (8) - ext2/3 filesystem backup
dump (rpm) - Programs for backing up and restoring ext2/ext3 filesystems

7. dumpe2fs (8) - dump ext2/ext3 filesystem information
dumpkeys (1) - dump keyboard translation tables
Index - E
e2label (8) - Change the label on an ext2/ext3 filesystem
echo (1) - display a line of text
echo (1p) - write arguments to standard output
echo [builtins] (1) - bash built-in commands, see bash(1)
edquota (8) - edit user quotas
egrep [grep] (1) - print lines matching a pattern
eject (1) - eject removable media
eject (rpm) - A program that ejects removable media using software control.
enable [builtins] (1) - bash built-in commands, see bash(1)
Env (3pm) - perl module that imports environment variables as scalars or arrays
env (1) - run a program in a modified environment
env (1p) - set the environment for command invocation
envsubst (1) - substitutes environment variables in shell format strings
esd (1) - The Enlightened Sound Daemon
esd-config (1) - The Enlightened Sound Daemon
esd-config (1) - The Enlightened Sound Daemon
esdcat (1) - The Enlightened Sound Daemon
esdctl (1) - The Enlightened Sound Daemon
esddsp (1) - attempt to reroute audio device to esd
esddsp [esdplay] (1) - attempt to reroute audio device to esd
esdmon (1) - The Enlightened Sound Daemon
esdrec (1) - The Enlightened Sound Daemon
esdsample (1) - The Enlightened Sound Daemon
ex (1p) - text editor
expand (1) - convert tabs to spaces
expand (1p) - convert tabs to spaces
e2label (8) - Change the label on an ext2/ext3 filesystem
echo (1) - display a line of text
echo (1p) - write arguments to standard output
echo [builtins] (1) - bash built-in commands, see bash(1)

8. edquota (8) - edit user quotas
egrep [grep] (1) - print lines matching a pattern
eject (1) - eject removable media
eject (rpm) - A program that ejects removable media using software control.
enable [builtins] (1) - bash built-in commands, see bash(1)
Env (3pm) - perl module that imports environment variables as scalars or arrays
env (1) - run a program in a modified environment
env (1p) - set the environment for command invocation
envsubst (1) - substitutes environment variables in shell format strings
esd (1) - The Enlightened Sound Daemon
esd-config (1) - The Enlightened Sound Daemon
esd-config (1) - The Enlightened Sound Daemon
esdcat (1) - The Enlightened Sound Daemon
esdctl (1) - The Enlightened Sound Daemon
esddsp (1) - attempt to reroute audio device to esd
esddsp [esdplay] (1) - attempt to reroute audio device to esd
esdmon (1) - The Enlightened Sound Daemon
esdrec (1) - The Enlightened Sound Daemon
esdsample (1) - The Enlightened Sound Daemon
ex (1p) - text editor
expand (1) - convert tabs to spaces
expand (1p) - convert tabs to spaces
expr (1) - evaluate expressions
expr (1p) - evaluate arguments as an expression
Index - F
factor (1) - factor numbers
false (1) - do nothing, unsuccessfully
false (1p) - return false value
fc-cache (1) - build font information cache files
fc-list (1) - list available fonts
fdformat (8) - Low-level formats a floppy disk
fdisk (8) - Partition table manipulator for Linux
fetchmail (1) - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
fetchmail (rpm) - A remote mail retrieval and forwarding utility

9. fgconsole (1) - print the number of the active VT
fgrep [grep] (1) - print lines matching a pattern
File::Basename (3pm) - Parse file paths into directory, filename and suffix
File::Compare (3pm) - Compare files or filehandles
File::Copy (3pm) - Copy files or filehandles
File::DosGlob (3pm) - DOS like globbing and then some
File::Find (3pm) - Traverse a directory tree
File::Glob (3pm) - Perl extension for BSD glob routine
File::Path (3pm) - create or remove directory trees
File::Spec (3pm) - portably perform operations on file names
File::Spec::Cygwin (3pm) - methods for Cygwin file specs
File::Spec::Epoc (3pm) - methods for Epoc file specs
File::Spec::Functions (3pm) - portably perform operations on file names
File::Spec::Mac (3pm) - File::Spec for Mac OS (Classic)
File::Spec::OS2 (3pm) - methods for OS/2 file specs
File::Spec::Unix (3pm) - File::Spec for Unix, base for other File::Spec modules
File::Spec::VMS (3pm) - methods for VMS file specs
File::Spec::Win32 (3pm) - methods for Win32 file specs
File::Temp (3pm) - return name and handle of a temporary file safely
File::stat (3pm) - by-name interface to Perl's built-in stat() functions
file (1) - determine file type
file (1p) - determine file type
file (rpm) - A utility for determining file types.
file-roller (rpm) - File Roller is a tool for viewing and creating archives
find (1) - search for files in a directory hierarchy
find (1p) - find files
finger (1) - user information lookup program
finger (rpm) - The finger client.
fmt (1) - simple optimal text formatter
fold (1) - wrap each input line to fit in specified width
fold (1p) - filter for folding lines
formail (1) - mail (re)formatter
free (1) - Display amount of free and used memory in the system
free (3p) - free allocated memory
free [malloc] (3) - Allocate and free dynamic memory
fsck (8) - check and repair a Linux file system
ftp (1) - Internet file transfer program
ftp (rpm) - The standard UNIX FTP (File Transfer Protocol) client.
fuser (1) - identify processes using files or sockets
fuser (1p) - list process IDs of all processes that have one or more files open

10. Index - G
gawk (1) - pattern scanning and processing language
gawk (rpm) - The GNU version of the awk text processing utility.
gawk [pgawk] (1) - pattern scanning and processing language
getent (1) - get entries from administrative database
getkeycodes (8) - print kernel scancode-to-keycode mapping table
gpasswd (1) - administer the /etc/group file
gpg (1) - encryption and signing tool
gpg-pubkey (rpm) - gpg(CentOS-5 Key (CentOS 5 Official Signing Key) <centos-5-key@centos.org>)
gpg-pubkey (rpm) - gpg(Stu Tomlinson <stu@nosnilmot.com>)
gpgv (1) - signature verification tool
gpm (8) - a cut and paste utility and mouse server for virtual consoles
gpm (rpm) - A mouse server for the Linux console.
gpm-root (1) - a default handler for gpm, used to draw menus on the root window
gprof (1) - display call graph profile data
grep (1) - print lines matching a pattern
grep (1p) - search a file for a pattern
grep (rpm) - The GNU versions of grep pattern matching utilities.
groff (1) - front-end for the groff document formatting system
groff (7) - a short reference for the GNU roff language
groff (rpm) - A document formatting system.
groffer (1) - display groff files and man~pages on X and tty
groupadd (8) - create a new group
groupdel (8) - delete a group
groupmod (8) - modify a group
groups (1) - print the groups a user is in
grpck (8) - verify integrity of group files
grpconv [pwconv] (8) - convert to and from shadow passwords and groups
gs (1) - Ghostscript (PostScript and PDF language interpreter and previewer)
gunzip [gzip] (1) - compress or expand files
gzexe (1) - compress executable files in place
gzip (1) - compress or expand files
gzip (rpm) - The GNU data compression program.

11. Index - H
halt (8) - stop the system
hdparm (8) - get/set hard disk parameters
hdparm (rpm) - A utility for displaying and/or setting hard disk parameters.
head (1) - output the first part of files
head (1p) - copy the first part of files
hexdump (1) - ascii, decimal, hexadecimal, octal dump
host (1) - DNS lookup utility
host.conf [host] (5) - resolver configuration file
hostid (1) - print the numeric identifier for the current host
hostname (1) - show or set the system's host name
htdigest (1) - manage user files for digest authentication
hwclock (8) - query and set the hardware clock (RTC)
Index - I
iconv (1) - Convert encoding of given files from one encoding to another
iconv (1p) - codeset conversion
iconv (3) - perform character set conversion
iconv (3p) - codeset conversion function
iconv.h [iconv] (0p) - codeset conversion facility
id (1) - print user identity
id (1p) - return user identity
ifconfig (8) - configure a network interface
info (1) - read Info documents
info (5) - readable online documentation
info (rpm) - A stand-alone TTY-based reader for GNU texinfo documentation.
init (8) - process control initialization
insmod (8) - simple program to insert a module into the Linux Kernel
install (1) - copy files and set attributes
install-catalog (8) - Manage a SGML or XML centralized catalog
install-datebook (1) - installs a new datebook entry onto your Palm handheld
install-expenses (1) - Install an expense record from various parameters and arguments passed at connection time
install-hinote (1) - installs a new Hi-Note entry onto your Palm handheld

12. install-info (1) - update info/dir entries
install-memo (1) - installs a new Memo Pad entry onto your Palm handheld
install-netsync (1) - reads or sets the Network Preferences information on a Palm Device
install-todo (1) - Updates the Palm ToDo list with one new entry
install-user (1) - reads or sets a Palm User and UserID on a Palm Device
ipcrm (1p) - remove an XSI message queue, semaphore set, or shared memory segment identifier
ipcrm (8) - remove a message queue, semaphore set or shared memory id
ipcs (1p) - report XSI interprocess communication facilities status
ipcs (8) - provide information on ipc facilities
iptables (8) - administration tool for IPv4 packet filtering and NAT
iptables (rpm) - Tools for managing Linux kernel packet filtering capabilities.
iptables-ipv6 (rpm) - IPv6 support for iptables.
iptables-restore (8) - Restore IP Tables
iptables-save (8) - Save IP Tables
iptables-restore (8) - Restore IP Tables
iptables-save (8) - Save IP Tables
isodump (5) - format of IEEE 1394 isochronous packets dump file
isodump [isoinfo] (8) - Utility programs for dumping and verifying iso9660 images
isoinfo (8) - Utility programs for dumping and verifying iso9660 images
isosize (8) - outputs the length of a iso9660 file system
isovfy [isoinfo] (8) - Utility programs for dumping and verifying iso9660 images
Index - K
kbd_mode (1) - report or set the keyboard mode
kbdrate (8) - reset the keyboard repeat rate and delay time
kill (1) - terminate a process
kill (1p) - terminate or signal processes
kill (2) - send signal to a process
kill (3p) - send a signal to a process or a group of processes
kill [builtins] (1) - bash built-in commands, see bash(1)
killall (1) - kill processes by name
klogd (8) - Kernel Log Daemon
kudzu (8) - detects and configures new and/or changed hardware on a system
kudzu (rpm) - The CentOS hardware probing tool.

13. Index - L
last (1) - show listing of last logged in users
lastb [last] (1) - show listing of last logged in users
lastlog (8) - reports the most recent login of all users or of a given user
ld (1) - The GNU linker
ld (8) - linux.so* - dynamic linker/loader
ld.so [ld] (8) - linux.so* - dynamic linker/loader
ldd (1) - print shared library dependencies
less (1) - opposite of more
less (3pm) - perl pragma to request less of something from the compiler
less (rpm) - A text file browser similar to more, but better.
lesskey (1) - specify key bindings for less
lftp (1) - Sophisticated file transfer program
lftp (rpm) - A sophisticated file transfer program
lftpget (1) - get a file with lftp(1)
link (1) - call the link function to create a link to a file
link (1p) - call link function
link (2) - make a new name for a file
link (3p) - link to a file
ln (1) - make links between files
ln (1p) - link files
loadkeys (1) - load keyboard translation tables
Locale::Constants (3pm) - constants for Locale codes
Locale::Country (3pm) - ISO codes for country identification (ISO 3166)
Locale::Currency (3pm) - ISO three letter codes for currency identification (ISO 4217)
Locale::Language (3pm) - ISO two letter codes for language identification (ISO 639)
Locale::Maketext (3pm) - framework for localization
Locale::Script (3pm) - ISO codes for script identification (ISO 15924)
locale (1) - Get locale - specific information
locale (1p) - get locale - specific information
locale (3pm) - Perl pragma to use and avoid POSIX locales for built-in operations
locale (5) - Describes a locale definition file
locale (7) - Description of multi-language support
locale.h [locale] (0p) - category macros
locate (1) - find files by name
lockfile (1) - conditional semaphore-file creator

14. logger (1) - a shell command interface to the syslog(3) system log module
logger (1p) - log messages
login (1) - sign on
login (3) - write utmp and wtmp entries
login.defs [login] (5) - shadow password suite configuration
logname (1) - print user's login name
logname (1p) - return the user's login name
logrotate (8) - rotates, compresses, and mails system logs
logrotate (rpm) - Rotates, compresses, removes and mails system log files.
look (1) - display lines beginning with a given string
look [Search::Dict] (3pm) - search for key in dictionary file
losetup (8) - set up and control loop devices
lpadmin (8) - configure cups printers and classes
lpinfo (8) - show available devices or drivers
lpmove (8) - move a job or all jobs to a new destination
lpq [lpq-cups] (1) - show printer queue status
lpr [lpr-cups] (1) - print files
lprm [lprm-cups] (1) - cancel print jobs
lpstat [lpstat-cups] (1) - print cups status information
ls (1) - list directory contents
ls (1p) - list directory contents
lsattr (1) - list file attributes on a Linux second extended file system
lspci (8) - list all PCI devices
lsmod (8) - program to show the status of modules in the Linux Kernel
lsusb (8) - list USB devices
mail (1) - send and receive mail
mailq (1) - print the mail queue
mailstats (8) - display mail statistics
mailto.conf [mailto] (5) - configuration file for cups email notifier

15. make (1) - GNU make utility to maintain groups of programs
make (1p) - maintain, update, and regenerate groups of programs (DEVELOPMENT)
make (rpm) - A GNU tool which simplifies the build process for users.
makemap (8) - create database maps for sendmail
man (1) - format and display the on-line manual pages
man (1p) - display system documentation
man (7) - macros to format man pages
man (rpm) - A set of documentation tools: man, apropos and whatis.
man-pages (rpm) - Man (manual) pages from the Linux Documentation Project.
man.config [man] (5) - configuration data for man
mattrib (1) - change MSDOS file attribute flags
mbadblocks (1) - tests a floppy disk, and marks the bad blocks in the FAT
mcat (1) - dump raw disk image
mcd (1) - change MSDOS directory
mcopy (1) - copy MSDOS files to/from Unix
md5sum (1) - compute and check MD5 message digest
mdeltree (1) - recursively delete an MSDOS directory and its contents
mdir (1) - display an MSDOS directory
mdu (1) - display the amount of space occupied by an MSDOS directory
mesg (1) - control write access to your terminal
mesg (1p) - permit or deny messages
mformat (1) - add an MSDOS filesystem to a low-level formatted floppy disk
minfo (1) - print the parameters of a MSDOS filesystem
mkdir (1) - make directories
mkdir (1p) - make directories
mkdir (2) - create a directory
mkdir (3p) - make a directory
mkdosfs (8) - create an MS-DOS file system under Linux
mke2fs (8) - create an ext2/ext3 filesystem
mke2fs [mkfs] (8) - create an ext2/ext3 filesystem
mke2fs.conf [mke2fs] (5) - Configuration file for mke2fs

16. mkfifo (1) - make FIFOs (named pipes)
mkfifo (1p) - make FIFO special files
mkfifo (3) - make a FIFO special file (a named pipe)
mkfifo (3p) - make a FIFO special file
mkfs (8) - build a Linux file system
mkisofs (8) - create an hybrid ISO9660/JOLIET/HFS filesystem with optional Rock Ridge attributes
mkisofs (rpm) - Creates an image of an ISO9660 filesystem.
mklost+found (8) - create a lost+found directory on a mounted Linux second extended file system
mkmanifest (1) - makes list of file names and their DOS 8+3 equivalent
mknod (1) - make block or character special files
mknod (2) - create a special or ordinary file
mknod (3p) - make a directory, a special file, or a regular file
mkswap (8) - set up a Linux swap area
mktemp (1) - make temporary filename (unique)
mktemp (3) - make a unique temporary filename
mktemp (3p) - make a unique filename (LEGACY)
mktemp (rpm) - A small utility for safely making /tmp files.
mlabel (1) - make an MSDOS volume label
mmd (1) - make an MSDOS subdirectory
mmount (1) - mount an MSDOS disk
mmove (1) - move or rename an MSDOS file or subdirectory
modinfo (8) - program to show information about a Linux Kernel module
modprobe (8) - program to add and remove modules from the Linux Kernel
modprobe.conf [modprobe] (5) - Configuration file/directory for modprobe
modprobe.d [modprobe] (5) - Configuration file/directory for modprobe
more (1) - file perusal filter for crt viewing
more (1p) - display files on a page-by-page basis
mount (2) - mount and unmount filesystems
mount (8) - mount a file system
mount.cifs [mount] (8) - mount using the Common Internet File System (CIFS)
mount.nfs [mount] (8) - mount a Network File System
mount.nfs4 [mount] (8) - mount a Network File System
mpartition (1) - partition an MSDOS hard disk
mrd (1) - remove an MSDOS subdirectory
mren (1) - rename an existing MSDOS file
mshowfat (1) - shows FAT clusters allocated to file

17. mtools (1) - utilities to access DOS disks in Unix
mtools (rpm) - Programs for accessing MS-DOS disks without mounting the disks.
mtools.conf [mtools] (5) - mtools configuration files
mtoolstest (1) - tests and displays the configuration
mtype (1) - display contents of an MSDOS file
mv (1) - move (rename) files
mv (1p) - move files
mzip (1) - change protection mode and eject disk on Zip/Jaz drive
netstat (8) - Print network connections, routing tables, interface statistics, masquerade connections, and multicast
memberships
newaliases (1) - rebuild the data base for the mail aliases file
newgrp (1) - log in to a new group
newgrp (1p) - change to a new group
newusers (8) - update and create new users in batch
nfsd (7) - special filesystem for controlling Linux NFS server
nfsstat (8) - list NFS statistics
nice (1) - run a program with modified scheduling priority
nice (1p) - invoke a utility with an altered nice value
nice (2) - change process priority
nice (3p) - change the nice value of a process
nm (1) - list symbols from object files
nm (1p) - write the name list of an object file (DEVELOPMENT)
nohup (1) - run a command immune to hangups, with output to a non-tty
nohup (1p) - invoke a utility immune to hangups
nslookup (1) - query Internet name servers interactively
nsupdate (8) - Dynamic DNS update utility
Index - P
passwd (1) - update a user's authentication tokens(s)
passwd (5) - password file
passwd (rpm) - The passwd utility for setting/changing passwords using PAM
passwd [sslpasswd] (1ssl) - compute password hashes
paste (1) - merge lines of files
paste (1p) - merge corresponding or subsequent lines of files

18. patch (1) - apply a diff file to an original
patch (1p) - apply changes to files
patch (rpm) - The GNU patch command, for modifying/upgrading files.
pathchk (1) - check whether file names are valid or portable
pathchk (1p) - check pathnames
ping (8) - send ICMP ECHO_REQUEST to network hosts
pinky (1) - lightweight finger
pmap (1) - report memory map of a process
portmap (8) - DARPA port to RPC program number mapper
portmap (rpm) - A program which manages RPC connections.
poweroff [halt] (8) - stop the system
pppd (8) - Point-to-Point Protocol Daemon
pr (1) - convert text files for printing
pr (1p) - print files
praliases (8) - display system mail aliases
printenv (1) - print all or part of environment
printf (1) - format and print data
printf (1p) - write formatted output
printf (3) - formatted output conversion
printf (3p) - print formatted output
printf [builtins] (1) - bash built-in commands, see bash(1)
ps (1) - report a snapshot of the current processes
ps (1p) - report process status
ptx (1) - produce a permuted index of file contents
pwck (8) - verify integrity of password files
pwconv (8) - convert to and from shadow passwords and groups
pwd (1) - print name of current/working directory
pwd (1p) - return working directory name
pwd [builtins] (1) - bash built-in commands, see bash(1)
pwd.h [pwd] (0p) - password structure
python (1) - an interpreted, interactive, object-oriented programming language
python (rpm) - An interpreted, interactive, object-oriented programming language.
python-elementtree (rpm) - Fast XML parser and writer
python-numeric (rpm) - Numerical Extension to Python
python-sqlite (rpm) - Python bindings for sqlite.
python-urlgrabber (rpm) - A high-level cross-protocol url-grabber

19. perl (1) - Practical Extraction and Report Language
perl (rpm) - The Perl programming language
Index - Q
quota (1) - display disk usage and limits
quota (rpm) - System administration tools for monitoring users' disk usage.
quotacheck (8) - scan a filesystem for disk usage, create, check and repair quota files
quotaon (8) - turn filesystem quotas on and off
quotaoff [quotaon] (8) - turn filesystem quotas on and off
quotastats (8) - Program to query quota statistics
rcp (1) - remote file copy
rdate (1) - get the time via the network
rdate (rpm) - Tool for getting the date/time from a remote machine.
rdev (8) - query/set image root device, RAM disk size, or video mode
rdist (1) - remote file distribution client program
rdist (rpm) - Maintains identical copies of files on multiple machines.
rdistd [rdist] (8) - remote file distribution server program
readcd (1) - read or write data Compact Discs
readelf (1) - Displays information about ELF files
readlink (1) - display value of a symbolic link
readlink (2) - read value of a symbolic link
readlink (3p) - read the contents of a symbolic link
reboot (2) - reboot or enable/disable Ctrl-Alt-Del
reboot [halt] (8) - stop the system
rename (1) - Rename files
rename (2) - change the name or location of a file
rename (3p) - rename a file
renice (8) - alter priority of running processes
repquota (8) - summarize quotas for a filesystem
reset [tput] (1) - initialize a terminal or query terminfo database
reset [tset] (1) - terminal initialization
resize2fs (8) - ext2/ext3 file system resizer

20. restore (8) - restore files or file systems from backups made with dump
rev (1) - reverse lines of a file
rexec (3) - return stream to a remote command
rlogin (1) - remote login
rm (1) - remove files or directories
rm (1p) - remove directory entries
rmail (8) - handle remote mail received via uucp
rmdir (1) - remove empty directories
rmdir (1p) - remove directories
rmdir (2) - delete a directory
rmdir (3p) - remove a directory
rmmod (8) - simple program to remove a module from the Linux Kernel
route (8) - show / manipulate the IP routing table
rpcinfo (8) - report RPC information
rpm (8) - RPM Package Manager
rpm (rpm) - The RPM package management system.
rpm-libs (rpm) - Libraries for manipulating RPM packages.
rpm-python (rpm) - Python bindings for apps which will manipulate RPM packages.
rsh (1) - remote shell
rsh (rpm) - Clients for remote access commands (rsh, rlogin, rcp).
rsh [ksh] (1) - shell, the
rsync (1) - faster, flexible replacement for rcp
rsync (rpm) - A program for synchronizing files over a network.
scanimage (1) - scan an image
scp (1) - secure copy (remote file copy program)
script (1) - make typescript of terminal session
sdiff (1) - find differences between two files and merge interactively
sed (1) - stream editor for filtering and transforming text
sed (1p) - stream editor
sed (rpm) - A GNU stream text editor.
sendmail (8) - an electronic mail transport agent
sendmail (rpm) - A widely used Mail Transport Agent (MTA).
sensors (1) - printing sensors information
sensors-detect (8) - detect hardware monitoring chips
sensors.conf [sensors] (5) - libsensors configuration file

21. seq (1) - print a sequence of numbers
setkeycodes (8) - load kernel scancode-to-keycode mapping table entries
setleds (1) - set the keyboard leds
setmetamode (1) - define the keyboard meta key handling
setquota (8) - set disk quotas
setsid (2) - creates a session and sets the process group ID
setsid (3p) - create session and set process group ID
setsid (8) - run a program in a new session
setterm (1) - set terminal attributes
sftp (1) - secure file transfer program
sftp-server (8) - SFTP server subsystem
sh (1p) - shell, the standard command language interpreter
sha1sum (1) - compute and check SHA1 message digest
showkey (1) - examine the codes sent by the keyboard
showmount (8) - show mount information for an NFS server
shred (1) - overwrite a file to hide its contents, and optionally delete it
shutdown (2) - shut down part of a full-duplex connection
shutdown (3p) - shut down socket send and receive operations
shutdown (8) - bring the system down
size (1) - list section sizes and total size
skill (1) - send a signal or report process status
slabtop (1) - display kernel slab cache information in real time
slattach (8) - attach a network interface to a serial line
sleep (1) - delay for a specified amount of time
sleep (1p) - suspend execution for an interval
sleep (3) - Sleep for the specified number of seconds
sleep (3p) - suspend execution for an interval of time
snice [skill] (1) - send a signal or report process status
sort (1) - sort lines of text files
sort (1p) - sort, merge, or sequence check text files
sort (3pm) - perl pragma to control sort() behaviour

22. split (1) - split a file into pieces
split (1p) - split files into pieces
ssh (1) - OpenSSH SSH client (remote login program)
ssh [slogin] (1) - OpenSSH SSH client (remote login program)
ssh-add (1) - adds RSA or DSA identities to the authentication agent
ssh-agent (1) - authentication agent
ssh-copy-id (1) - install your identity.pub in a remote machine's authorized_keys
ssh-keygen (1) - authentication key generation, management and conversion
ssh-keyscan (1) - gather ssh public keys
ssh-keysign (8) - ssh helper program for hostbased authentication
ssh-add (1) - adds RSA or DSA identities to the authentication agent
ssh-agent (1) - authentication agent
ssh-keygen (1) - authentication key generation, management and conversion
ssh-keyscan (1) - gather ssh public keys
sshd (8) - OpenSSH SSH daemon
stat (1) - display file or file system status
stat (2) - get file status
stat (3p) - get file status
strings (1) - print the strings of printable characters in files
strings (1p) - find printable strings in files
strings.h [strings] (0p) - string operations
strip (1) - Discard symbols from object files
strip (1p) - remove unnecessary information from executable files (DEVELOPMENT)
stty (1) - change and print terminal line settings
stty (1p) - set the options for a terminal
stty [unimplemented] (2) - unimplemented system calls
su (1) - run a shell with substitute user and group IDs
sudo (8) - execute a command as another user
sudo (rpm) - Allows restricted root access for specified users.
sudo [sudoedit] (8) - execute a command as another user
sum (1) - checksum and count the blocks in a file
swapoff [swapon] (2) - start/stop swapping to file/device
swapoff [swapon] (8) - enable/disable devices and files for paging and swapping
swapon (2) - start/stop swapping to file/device
swapon (8) - enable/disable devices and files for paging and swapping
sync (1) - flush file system buffers
sync (2) - commit buffer cache to disk
sync (3p) - schedule file system updates
sync (8) - synchronize data on disk with memory

23. sysctl (2) - read/write system parameters
sysctl (8) - configure kernel parameters at runtime
sysctl.conf [sysctl] (5) - sysctl(8) preload/configuration file
sysklogd (8) - Linux system logging utilities
sysklogd (rpm) - System logging and kernel message trapping daemons.
Index - T
tac (1) - concatenate and print files in reverse
tail (1) - output the last part of files
tail (1p) - copy the last part of a file
tailf (1) - follow the growth of a log file
talk (1) - talk to another user
talk (1p) - talk to another user
talk (rpm) - Talk client for one-on-one Internet chatting.
tar (1) - The GNU version of the tar archiving utility
tar (rpm) - A GNU file archiving program
tar.h [tar] (0p) - extended tar definitions
taskset (1) - retrieve or set a processes's CPU affinity
tcpd (8) - access control facility for internet services
tcpdump (8) - dump traffic on a network
tcpdump (rpm) - A network traffic monitoring tool.
tcpslice (8) - extract pieces of and/or glue together tcpdump files
tee (1) - read from standard input and write to standard output and files
tee (1p) - duplicate standard input
tee (2) - duplicating pipe content
telinit [init] (8) - process control initialization
telnet (1) - user interface to the TELNET protocol
telnet (rpm) - The client program for the telnet remote login protocol.
Test (3pm) - provides a simple framework for writing test scripts
Test [Mail::SpamAssassin::Plugin::Test] (3pm) - test plugin
Test::Builder (3pm) - Backend for building test libraries
Test::Builder::Module (3pm) - Base class for test modules
Test::Builder::Tester (3pm) - test testsuites that have been built with Test::Builder
Test::Builder::Tester::Color (3pm) - turn on colour in Test::Builder::Tester
Test::Harness (3pm) - Run Perl standard test scripts with statistics
Test::Harness::Assert (3pm) - simple assert
Test::Harness::Iterator (3pm) - Internal Test::Harness Iterator

24. Test::Harness::Point (3pm) - object for tracking a single test point
Test::Harness::Straps (3pm) - detailed analysis of test results
Test::Harness::TAP (3pm) - Documentation for the TAP format
Test::More (3pm) - yet another framework for writing test scripts
Test::Simple (3pm) - Basic utilities for writing tests
Test::Tutorial (3pm) - A tutorial about writing really basic tests
test (1) - check file types and compare values
test (1p) - evaluate expression
test [builtins] (1) - bash built-in commands, see bash(1)
Time::HiRes (3pm) - High resolution alarm, sleep, gettimeofday, interval timers
Time::Local (3pm) - efficiently compute time from local and GMT time
Time::gmtime (3pm) - by-name interface to Perl's built-in gmtime() function
Time::localtime (3pm) - by-name interface to Perl's built-in localtime() function
Time::tm (3pm) - internal object used by Time::gmtime and Time::localtime
time (1) - time a simple command or give resource usage
time (1p) - time a simple command
time (2) - get time in seconds
time (3p) - get time
time (7) - overview of time
time (rpm) - A GNU utility for monitoring a program's use of system resources.
time.conf [time] (5) - configuration file for the pam_time module
time.h [time] (0p) - time types
tload (1) - graphic representation of system load average
tmpwatch (8) - removes files which haven't been accessed for a period of time
tmpwatch (rpm) - A utility for removing files based on when they were last accessed.
top (1) - display Linux tasks
touch (1) - change file timestamps
touch (1p) - change file access and modification times
tr (1) - translate or delete characters
tr (1p) - translate characters
tracepath (8) - traces path to a network host discovering MTU along this path
traceroute (8) - print the route packets trace to network host
traceroute (rpm) - Traces the route taken by packets over an IPv4/IPv6 network
troff (1) - the troff processor of the groff text formatting system
true (1) - do nothing, successfully
true (1p) - return true value
tset (1) - terminal initialization
tsort (1) - perform topological sort
tsort (1p) - topological sort
tty (1) - print the file name of the terminal connected to standard input
tty (1p) - return user's terminal name

25. tty (4) - controlling terminal
tty ioctl [tty_ioctl] (4) - ioctls for terminals and serial lines
tune2fs (8) - adjust tunable filesystem parameters on ext2/ext3 filesystems
tunelp (8) - set various parameters for the lp device
umount (8) - unmount file systems
umount [mount] (2) - mount and unmount filesystems
umount.cifs [umount] (8) - for normal, non-root users, to unmount their own Common Internet File System (CIFS) mounts
umount.nfs [umount] (8) - unmount a Network File System
umount.nfs4 [umount] (8) - unmount a Network File System
uname (1) - print system information
uname (1p) - return system name
uname (2) - get name and information about current kernel
uname (3p) - get the name of the current system
unexpand (1) - convert spaces to tabs
unexpand (1p) - convert spaces to tabs
unicode_start (1) - put keyboard and console in unicode mode
unicode_stop (1) - revert keyboard and console from unicode mode
uniq (1) - report or omit repeated lines
uniq (1p) - report or filter out repeated lines in a file
uptime (1) - Tell how long the system has been running
useradd (8) - create a new user or update default new user information
userdel (8) - delete a user account and related files
usermod (8) - modify a user account
users (1) - print the user names of users currently logged in to the current host
usleep (1) - sleep some number of microseconds
usleep (3) - suspend execution for microsecond intervals
usleep (3p) - suspend execution for an interval
uudecode (1p) - decode a binary file
uuencode (1p) - encode a binary file
uuidgen (1) - command-line utility to create a new UUID value
vdir (1) - list directory contents
vi (1p) - screen-oriented (visual) display editor

26. vim (1) - Vi IMproved, a programmers text editor
vim-common (rpm) - The common files needed by any version of the VIM editor.
vim-enhanced (rpm) - A version of the VIM editor which includes recent enhancements.
vim-minimal (rpm) - A minimal version of the VIM editor.
vmstat (8) - Report virtual memory statistics
volname (1) - return volume name
Index - W
w (1) - Show who is logged on and what they are doing
warnquota (8) - send mail to users over quota
watch (1) - execute a program periodically, showing output fullscreen
wc (1) - print the number of newlines, words, and bytes in files
wc (1p) - word, line, and byte or character count
Wget [wget] (1) - The non-interactive network downloader
wget (rpm) - A utility for retrieving files using the HTTP or FTP protocols.
whatis (1) - search the whatis database for complete words
whereis (1) - locate the binary, source, and manual page files for a command
which (1) - shows the full path of (shell) commands
which (rpm) - Displays where a particular program in your path is located.
who (1) - show who is logged on
who (1p) - display who is on the system
whoami (1) - print effective userid
write (1) - send a message to another user
write (1p) - write to another user
write (2) - write to a file descriptor
write (3p) - write on a file
Index - Y
yacc (1p) - yet another compiler compiler (DEVELOPMENT)
yes (1) - output a string repeatedly until killed
ypbind (8) - NIS binding process
ypbind (rpm) - The NIS daemon which binds NIS clients to an NIS domain.

27. ypcat (1) - print values of all keys in a NIS database
ypmatch (1) - print the values of one or more keys from a NIS map
yppasswd (1) - change your password in the NIS database
yppoll (8) - return version and master server of a NIS map
ypset (8) - bind ypbind to a particular NIS server
yptest (8) - test NIS configuration
ypwhich (1) - return name of NIS server or map master
Index - Z
zcat (1p) - expand and concatenate data
zcat [gzip] (1) - compress or expand files
zcmp [zdiff] (1) - compare compressed files
zdiff (1) - compare compressed files
zdump (8) - time zone dumper
zforce (1) - force a '.gz' extension on all gzip files
zgrep (1) - search possibly compressed files for a regular expression
zic (8) - time zone compiler
zless (1) - file perusal filter for crt viewing of compressed text
zmore (1) - file perusal filter for crt viewing of compressed text
znew (1) - recompress .Z files to .gz files
http://www.yolinux.com/TUTORIALS/LinuxTutorialSysAdmin.html