Linux Commands


Vishal Vyas

Linux Commands

This is a list of commands that gives you just enough information to decide what command you want to use.

A

  • alias – allows you to create shorter or more familiar names for commonly used commands
  • apropos – search the manual page names and descriptions
  • at – execute a command-line task at a specified future time
  • awk – print only the nth word of an input line and more

B

  • badblocks – a command disk utility
  • bash – a shell
  • beep – customized audible alerts
  • bunzip2 – unpack files packed with bzip2
  • bzip2 – a pack utility

C

  • cat – receive strings from stdin or a file and output them to stdout or a file
  • chgrp – change the group ownership of a file
  • chmod – change the permission mode of a file
  • chown – change the owner of a file
  • chroot – change the position of a root directory in filesystem
  • chsh – change the shell of a user
  • cp – copy a file
  • cpio – pack or unpack files in cpio archives or tarballs
  • cron – schedule tasks to be executed regularly at a specific time
  • crontab – control the cron service
  • cut – display specific coloumns of a file delimited by a character
  • cvs – a version management system

D

  • date – output or set date and time
  • dd – dump a disk to/from a file and more
  • df – show how much free disk space there is
  • diff – show the difference between two files and more
  • dig – show answer of DNS lookup of queried name server
  • disown – disowns a job (removes the pid of the job). Even when the shell exits, the job won’t stop running
  • du – show how much disc space is used up

E

  • echo – echo a string/value to stdout
  • env – show all environment variables
  • exit – exit most shells
  • export – set an environment variable in the bash or zsh

F

  • fdisk – partition a disc
  • fg – fetch a process from the background to the foreground
  • file (command) – determine a file’s type
  • find – find a file depending on its name, size, change date or other attributes
  • ftp – get files from the internet

G

  • g++ – compile C++ code
  • gcc – compile C code
  • grep – grab for patterns in a file and more
  • groups – show what groups your user is in
  • gunzip – unpack files from a special format
  • gzip – pack files in a special format

H

  • halt – shut down your computer
  • head – show only the first n lines of a file and more
  • hexdump – show a file’s content in hexadecimal numbers and more
  • history (command) – show a command history in the bash shell
  • hostname – show your computer’s name
  • hwinfo – show your available hardware

I

  • id – show your user and groups ids
  • ifconfig – show your ip address and more
  • info – show info about a given command
  • init – reboot or change runlevel
  • iptables – show your firewall configuration
  • iptraf – Interactive IP LAN monitor

J

  • jobs – gives a list of current background jobs (processes)

K

  • kill – kill a process
  • killall – kill all processes with a given name

L

  • ldd – show dynamic libraries needed by an executable
  • less – show output in a viewer where you can scroll and search
  • ln – link a file
  • ls – list a file
  • lsmod – list loaded kernel modules
  • lsof – list open files and listening sockets
  • lspci – list all pci devices
  • lsusb – list usb devices

M

  • make – compile software and more
  • man – get help on questions that you never wanted to ask
  • md5sum – compute the md5 sum of a file and more
  • mkdir – make a directory
  • mkfs – format a device
  • minicom – communicate over your RS232 interface
  • more – show input in a searchable pager
  • mount – prepare a device for reading and writing
  • mv – move a file (can also be renaming)

N

  • netcat – Send some bytes to the network
  • netstat – get information on listening sockets, open ports and more
  • nice – set a process’ priority
  • nm – list the names of functions in an object file
  • nmap – network and port scanner tool

O

  • objdump – show information about object files
  • openssl – create cryptographic server certificates and more

P

  • passwd – change your and other’s password
  • ping – show if a given computer is up and running
  • ps – show running processes
  • pwd – show your current working directory

Q

  • quota – manage how much resources the user is allowed to consume

R

  • rar – rar files/directories
  • read – read a string from your keyboard and more
  • reboot – reboot the computer
  • rename – rename a file
  • rm – delete a file
  • route – manage your network routing table
  • rpm – a package management backend for Redhat and Fedora
  • rsync – synchronize your folders over the network

S

  • scp – (secure copy) over a network
  • screen – a terminal multiplexer
  • sed – manipulate a stream of characters (scripting language)
  • setenv – change the value of an environment variable in the csh
  • shuf – generate random permutations
  • shutdown – shutdowns/reboots the system
  • sleep – wait/delay some time
  • ssh – login into / execute commands in a remote host
  • su – change user
  • sudo – execute the command as another user (usually root- /etc/sudoers)

T

  • tail – show only the last n lines of a file and more
  • tar – pack files in a special format
  • tcpdump – dump the tcp network traffic
  • tee – multiplex cli output
  • time – show the time needed by a command to finish
  • top – show the top CPU consuming processes and more
  • touch – create a file or update its time stamp
  • traceroute – show the route a package takes over the network
  • tac – print the file in reverse. (opposite of cat) (cat X tac)

U

  • ulimit – show the limits of your user
  • umount – unmount a device (Often requires sudo permissions)
  • uname – show the running kernel’s version and more
  • uniq – remove repeated lines in a sorted file
  • unzip – unpack files
  • uptime – show the time since your computer was last switched on
  • useradd – add a user
  • userdel – delete a user
  • usermod – modify a user

V

  • Vgcreate – create lvm volume groups
  • Vgdisplay – display lvm volume groups
  • Vgs – show information about lvm volume groups
  • Vgscan – scan for lvm volume groups
  • vim – its not a text editor like Notepad, it is an IDE
  • Vmstat – show input/output values, swap, memory consumption and more

W

  • w – print who is logged in to your system
  • wc – word count (word,line,char)
  • which – print the path where you find an executable file
  • whoami – print your effective user name

X

  • xargs – hand over stdin as a parameter
  • xev – show information about your keystrokes and more
  • xkill – kill a window that is in your way
  • xosview – show CPU/memory/hard Drive activity and more

Y

  • yacc – A C parser generator
  • yes – repeatedly output a string
  • yum – a package management frontend for Redhat & Fedora
  • yast – a package management frontend for SUSE

Z

  • zip – pack a file

7 Responses to “Linux Commands”

  1. hariharan June 29, 2010 at 2:01 pm #

    thank u vishal. gr8

    • Vishal June 29, 2010 at 2:04 pm #

      Welcome:)

      ………..@……..

  2. Amit January 25, 2011 at 2:58 pm #

    Great work…. 🙂

  3. mayank April 28, 2011 at 7:20 am #

    thanks for Linux commends

  4. Sandeep January 21, 2012 at 3:15 pm #

    thanku vishal… thanks a lot…

  5. Mitchel April 10, 2013 at 10:45 am #

    While I do feel the content is spectacular, I just
    want to know if you really authored it. I found a virtually exact
    replicate of this on some other web site.

  6. Francine April 17, 2013 at 8:22 pm #

    Terrific article, but what’s your opinion about making a second part to this post? What you covered was terrific, do not get me wrong, I simply believe there was some important concerns you left un-answered. I think many of us would enjoy to read the Second part; if you could write it that is.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: