Linux Commands

Table

│ A │ B │ C │ D │ E │ F │ G │ H │ I │ J │ K │ L │ M │ N │ O │ P │ Q │ R │ S │ T │ U │ V │ W │ X │ Y │ Z │

Top 100 Linux Commands Cheat Sheet

Top 100 Linux Commands

I have prepared a help and manual for Linux, based on Ubuntu (cause other distribution are using same kernel the commands are mostly same). However, if you require specific guidance for a different Linux distribution, this resource can be helpful.

manned

A

accept command

accept help

Accept or Reject jobs to a destination, such as a printer.

access command

access help

Check a user’s RWX(read, write and execute) permission for a file.

accton command

accton help

Used to turn on or turn off the process for accounting or change info process accounting file.

aclocal command

aclocal help

Used to automatically generate aclocal.m4 files from configure.in file.

acpi command

acpi help

acpid command

acpid help

Show information about the Advanced Configuration and Power Interface.

addr2line command

addr2line help

Used to convert addresses into file names and line numbers.

addresses command

addresses help

Formats for internet mail addresses.

agetty command

agetty help

An alternative Linux Getty that manages physical or virtual terminals to allow multi-user access.

alias, unalias commands

alies help

Create an alias, a shortcut that references a command.

alsactl command

alsactl help

Access advanced controls for ALSA soundcard driver.

amidi command

amidi help

Perform read/write operation for ALSA RawMIDI ports.

amixer command

amixer help

Access CLI-based mixer for ALSA soundcard driver.

anacron command

anacron help

Used to run commands periodically.

apachetop command

apachetop help

aplay command

aplay help

Sound recorder and player for CLI.

aplaymidi command

aplaymidi help

CLI utility used to play MIDI files.

apm command

apm help

Show Advanced Power Management (APM) hardware info on older systems.

apmd command

apmd help

Used to handle events reported by APM BIOS drivers.

apropos command

apropos help

Shows the list of all man pages containing a specific keyword.

apt-get command

apt help

Command-line utility to install/remove/update packages based on APT system.

apt command

apt help

Advanced Package Tool, a package management system for Debian and derivatives.

aptitude command

aptitude help

Another utility to add/remove/upgrade packages based on the APT system.

ar command

ar help

A utility to create/modify/extract from archives.

arch command

arch help

Display print machine hardware name.

arecord command

arecord help

Just like aplay, it’s a sound recorder and player for ALSA(Advanced Linux Sound Architecture) soundcard driver.

arecordmid command

arecordmid help

Record standard MIDI files.

arecord command

arecord help

arp command

arp help

Used to make changes to the system’s ARP cache.

aspell command

aspell help

An interactive spell checker utility.

at command

at help

Used to schedule command execution at specified date & time, reading commands from an input file.

atd command

atd help

Used to execute jobs queued by the at command.

atop command

atop help

atq command

atq help

List a user’s pending jobs for the at command.

aplay command

aplay help

atrm command

atrm help

Delete jobs queued by the at command.

aumix command

aumix help

An audio mixer utility.

autoconf command

autoconf help

Generate configuration scripts from a TEMPLATE-FILE and send the output to standard output.

autoheader command

autoheader help

Create a template header for configure.

automake command

automake help

Creates GNU standards-compliant Makefiles from template files.

autoreconf command

autoreconf help

Update generated configuration files.

autoscan command

autoscan help

Generate a preliminary configure.in file.

B

badblocks command

badblocks help

Search a disk partition for bad sectors.

banner command

banner help

Used to print the ASCII character string in large letter to standard output

basename command

basename help

It strips directory information and suffixes from file names ie it prints the file name NAME with any leading directory components removed

batch command

batch help

Used to read commands from standard input or a specified file and execute them when system load levels permit ie when the load average drops below

bc command

bc help

Used for command line calculator

bg command

bg help

Used to place foreground jobs in background

biff command

biff help

A mail notification system for unix that notifies the user at the command line when new mail arrives and tells from whom it is

bind command

bind help

Used to set Readline key bindings and variables

bison command

bison help

It is basically a parser generator similar to yacc

break command

break help

Used to terminate the execution of for loop, while loop and until loop

builtin command

builtin help

Used to run a shell builtin, passing it arguments(args), and also to get the exit status

bzcmp command

bzcmp help

Used to invoke the cmp utility on bzip compressed files

bzdiff command

bzdiff help

Used to compare the bzip compressed files

bzgrep command

bzgrep help

Used to search for a pattern or an expression but inside a bzip-compressed file

bzip2 command

bzip2 help

Used to compress and decompress the files

C

cal command

cal help

Used to see the calendar of a specific month or a whole year By default, it shows current month’s calendar as output.

cardctl command

cardctl help

Used to control PCMCIA sockets and select configuration schemes.

cardmgr command

cardmgr help

Keeps an eye on the added/removes sockets for PCMCIA devices.

case command

case help

It is the best alternative when we had to use multiple if/elif on a single variable

cat command

cat help

cat - create, view and concatenate files

cc command

cc help

GNU C and C++ compiler.

cp command

cp help

cp - copy files and directories

cat command

cat help

cat - create, view and concatenate files

ccrypt command

ccrypt help

Used for encryption and decryption of data.

cd command

cd help

cd - change director

• cd / ----> change to the root directory

• cd ~ ----> change to your home directory

• cd ----> change to your home directory

• cd ----> change to the directory above your current ie parent directory

• cd ----> change to the directory you currently in

• cd - ----> change to the last visited path

cdparanoia command

cdparanoia help

Record audio from CD more reliably using data-verification algorithms.

cdrdao command

cdrdao help

Used to write all the content specified to a file to a CD all at once.

cfdisk command

cfdisk help

Show or change the disk partition table.

chage command

chage help

Used to view and change the user password expiry information

chattr command

chattr help

It is a file system command which is used for changing the attributes of a file in a directory

chdir command

chdir help

Used to change active working directory.

chfn command

chfn help

It allows you to change a user’s name and other details easily chfn stands for Change finger

chgrp command

chgrp help

Used to change the group ownership of a file or directory

chkconfig command

chkconfig help

Used to list all available services and view or update their run level settings

chmod command

chmod help

Change access permission for a file(s).

chown command

chown help

Change the owner or group for a file.

chpasswd command

chpasswd help

Update password in a batch.

chroot command

chroot help

Run a command with root directory.

chrt command

chrt help

Alter process attributed in real-time.

chsh command

chsh help

Used to change the user’s login shell(currently login shell)

chvt command

chvt help

Used to switch between the different TTY (TeleTYpewriter) terminals available

cksum command

cksum help

Used to display a CRC(Cyclic Redundancy Check) value, the byte size of the file and the name of the file to standard output

cmp command

cmp help

Used to compare the two files byte by byte and helps you to find out whether the two files are identical or not

colcrt command

colcrt help

Used to format the text processor output so that it can be viewed on Cathode Ray Tube displays

clorm command

clorm help

Remove columns from the lines of a file.

column command

column help

Used to display the contents of a file in columns

comm command

comm help

Compares two sorted files line by line and write to standard output; the lines that are common and the lines that are unique

compress command

compress help

Used to reduce the file size After compression, the file will be available with an added Z extension

continue command

continue help

Used to skip the current iteration in for, while and until loop

cp command

cp help

Copy contents of one file to another.

cpio command

cpio help

cpio stands for “copy in, copy out“ It is used for processing the archive files like *cpio or *tar This command can copy files to and from archives

cron command

cron help

A software utility, offered by Linux-like operating system which automates the scheduled task at a predetermined time

crond command

crond help

Same work as cron.

crontab command

crontab help

A list of commands that you want to run on a regular schedule, and also the name of the command used to manage that list.

csplit command

csplit help

Used to split any file into many parts as required by the user.

ctags command

ctags help

It allows quick access across the files (For example quickly seeing definition of a function)

cupsd command

cupsd help

It is a type of scheduler for CUPS (Common Unit Printing System) It implements the printing system on the basis of the Internet Printing Protocol

curl command

curl help

A tool to transfer data to or from a server, using any of the supported protocols

cut command

cut help

For cutting out the sections from each line of files and writing the result to standard output

cvs command

cvs help

Used to store the history of a file Whenever a file gets corrupted or anything goes wrong “cvs” help us to go back to the previous version and restore our file

D

date command

date help

Used to display the system date and time It is also used to set date and time of the system

dd command

dd help

debugfs command

debugfs help

declare command

declare help

Used to declare shell variables and functions, set their attributes and display their values

depmod command

depmod help

Used to generate a list of dependency description of kernel modules and its associated map files

ddrescue command

ddrescue help

du command

du help

diff command

diff help

dmesg command

dmesg help

dd command

dd help

It is a command-line utility for Unix and Unix-like operating systems whose primary purpose is to convert and copy files

diff command

diff help

Used to display the differences in the files by comparing the files line by line

dirname command

dirname help

Used to remove the trailing forward slahes “/” from the NAME and prints the remaining portion

dirs command

dirs help

Used to display the list of currently remembered directories

disable command

disable help

Used to stop the printers or classes

dmesg command

dmesg help

Used to examine the kernel ring buffer and print the message buffer of kernel

domainname command

domainname help

Used to return the Network Information System (NIS) domain name of the host

dstat command

dstat help

Used to retrieve information or statistics form components of the system such as network connections, IO devices, or CPU, etc

dump command

dump help

Used to backup the filesystem to some storage device

dumpkeys command

dumpkeys help

Used for the dump keyboard translation tables

E

echo command

echo help

eject command

eject help

It allows ejecting a removable media (typically a CD-ROM, floppy disk, tape, or JAZ or ZIP disk) using the software

emacs command

emacs help

It is a editor having simple user interface Also, there is no insert mode in this editor It only have editing mode

enable command

enable help

Used to start the printers or classes

env command

env help

Used to either print environment variables It is also used to run a utility or command in a custom environment

eval command

eval help

Built-in command used to execute arguments as a shell command

exit command

exit help

Used to exit the shell where it is currently running

expand command

expand help

Allows you to convert tabs into spaces in a file and when no file is specified it reads from standard input

expect command

expect help

This command or scripting language works with scripts that expect user inputs It automates the task by providing inputs

export command

export help

It is bash shell BUILTINS commands, which means it is part of the shell It marks an environment variables to be exported to child-processes

expr command

expr help

It evaluates a given expression and displays its corresponding output

F

factor command

factor help

Used to print the prime factors of the given numbers, either given from command line or read from standard input

fc command

fc help

Used to list, edit or re-execute the commands previously entered into an interactive shell

fc-list command

fc-list help

It is used to list the available fonts and font styles Using the format option, the list of all fonts can be filtered and sorted out

fg command

fg help

Used to put a background job in foreground

file command

file help

Used to determine the type of a file file type may be of human-readable(eg ‘ASCII text’) or MIME type(eg ‘text/plain; charset=us-ascii’)

find command

find help

Used to find files and directories and perform subsequent operations on them

finger command

finger help

It is a user information lookup command which gives details of all the users logged in

fmt command

fmt help

Works as a formatter for simplifying and optimizing text files

fold command

fold help

It wraps each line in an input file to fit a specified width and prints it to the standard output

for command

for help

Used to repeatedly execute a set of command for every element present in the list

find command

find help

fdisk command

fdisk help

find command

find help

fun command

Fun help

Used to draw various type of patterns on the terminal

function command

function help

Used to create functions or methods

G

gawk command

gawk help

Used for pattern scanning and processing language

gdb command

gdb help

GNU Debugger tool helps to debug the programs written in C, C++, Ada, Fortran, etc

getent command

getent help

Used to get the entries in a number of important text files called databases

gpasswd command

gpasswd help

Used to administer the /etc/group and /etc/gshadow

groupdel command

groupadd help

Used to create a new user group

groupdel command

groupdel help

Used to delete a existing group

groupmod command

groupmod help

Used to modify or change the existing group on Linux system

groups command

groups help

Groups are the collection of users Groups make it easy to manage users with the same security and access privileges

grpck command

grpck help

It verifies the integrity of the groups information It checks that all entries in /etc/group and /etc/gshadow have the proper format and contain valid data

grpconv command

grpconv help

It is used to convert to shadow groups The grpconv command creates a gshadow from the group and an optionally existing gshadow

gs command

gs help

This command invokes Ghostscript, which is an interpreter of Adobe Systems PostScript and Portable Document Format(PDF) languages

gunzip command

gunzip help

Used to compress or expand a file or a list of files in Linux

gzexe command

gzexe help

Used to compress executable files and also used to automatically uncompress and execute the files

grep command

grep help

GoAccess command

GoAccess help

gzip command

gzip help

This command compresses files Each single file is compressed into a single file

H

halt command

halt help

Used to instruct the hardware to stop all the CPU functions Basically, it reboots or stops the system

head command

head help

hash command

hash help

Used to maintain a hash table of recently executed programs

hdparm command

hdparm help

Used to get statistics about the hard disk, alter writing intervals, acoustic management, and DMA settings

hexdump command

hexdump help

Used to filter and display the specified files, or standard input in a human readable specified format

history command

history help

Used to view the previously executed command

hostid command

hostid help

Used to displays the Host’s ID in hexadecimal format

hostname command

hostname help

Used to obtain the DNS(Domain Name System) name and set the system’s hostname or NIS(Network Information System) domain name

hostnamectl command

hostnamectl help

Provides a proper API used to control Linux system hostname and change its related settings

hwclock command

hwclock help

Utility for accessing the hardware clock, also called Real Time Clock (RTC)

I

iconv command

iconv help

Used to convert some text in one encoding into another encoding

id command

id help

Used to find out user and group names and numeric ID’s (UID or group ID) of the current user or any other user in the server

info command

info help

if command

if help

Used to execute commands based on conditions

ifconfig command

ifconfig help

Used to configure the kernel-resident network interfaces

iftop command

iftop help

It is a network analyzing tool used by system administrators to view the bandwidth related stats

ifup command

ifup help

It basically brings the network interface up, allowing it to transmit and receive dat

import command

import help

Used for capturing a screenshot for any of the active pages we have and it gives the output as an image file

insmod command

insmod help

Used to insert modules into the kernel

install command

install help

Used to copy files and set attributes

iostat command

iostat help

Used for monitoring system input/output statistics for devices and partitions

iotop command

iotop help

Used to display and monitor the disk IO usage details and even gets a table of existing IO utilization by the process

ipcrm command

ipcrm help

Used to remove some IPC(Inter-Process Communication) resources It eliminates the IPC objects and their associated data structure form the system

iwconfig command

iwconfig help

Used to display the parameters, and the wireless statistics which are extracted from /proc/net/wireless

J

jobs command

jobs help

Show the list of active jobs and their status.

jnettop command

jnettop help

join command

join help

It is a command line utility for joining lines of two files based on a key field present in both the files

journalctl command

journalctl help

Used to view systemd, kernel and journal logs

K

kill command

kill help

Used to terminate processes manually kill command sends a signal to a process which terminates the process

L

last command

last help

Used to display the list of all the users logged in and out since the file /var/log/wtmp was created

Logwatch command

Logwatch help

locate command

locate help

less command

less help

let command

let help

Used to evaluate arithmetic expressions on shell variables

ls command

ls help

ls - listing files and directories

ln command

ln help

Used to create links between files

locate command

locate help

Used to find the files by name

look command

look help

Shows the lines beginning with a given string

lsblk command

help

Used to display details about block devices and these block devices(Except ram disk) are basically those files that represent devices connected to the pc

lshw command

lshw help

Used to generate the detailed information of the system’s hardware configuration from various files in the /proc directory

lsusb command

lsusb help

Used to display the information about USB buses and the devices connected to them

M

man command

man help

mailq command

mailq help

This command in Linux prints the mail queue ie the list of messages that are there in the mail queue

mv command

mv help

mkdir command

mkdir help

mkdir - create directories

modinfo command

modinfo help

Used to display the information about a Linux Kernel module

mount command

mount help

Used to mount the filesystem found on a device to big tree structure(Linux filesystem) rooted at ‘/‘

mpstat command

mpstat help

Used to report processor related statistics

N

nc(netcat) command

nc help

It is one of the powerful networking tool, security tool or network monitoring tool

netstat command

netstat help

Displays various network related information such as network connections, routing tables, interface statistics, masquerade connections, multicast memberships, etc

nmcli command

nmcli help

Used for controlling NetworkManager nmcli command can also be used to display network device status, create, edit, activate/deactivate, and delete network connections

nslookup command

nslookup help

It is a network administration tool for querying the Domain Name System (DNS) to obtain domain name or IP address mapping or any other specific DNS record

P

paste command

paste help

Used to join files horizontally (parallel merging) by outputting lines consisting of lines from each file specified, separated by tab as delimiter, to the standard output

pidof command

pidof help

Used to find out the process IDs of a specific running program

ping command

ping help

Used to check the network connectivity between host and server/host

pmap command

pmap help

ps command

ps help

poweroff command

poweroff help

ping command

ping help

pwd command

pwd help

pwd - print current working directory (= at what path the user currently located)

printf command

printf help

Used to display the given string, number or any other format specifier on the terminal window

ranlib command

ranlib help

Used to generate index to archive

R

rcp command

rcp help

Used to copy files from one computer to another computer

read command

read help

Reads up the total number of bytes from the specified file descriptor into the buffer

rmdir command

rmdir help

rm command

rm help

rm - remove files and directories

readelf command

readelf help

Used to get information of ELF(Executable and Linkable Format) Files

readlink command

readlink help

Used to print resolved symbolic links or canonical file names

reboot command

reboot help

Instructs the system to rest or reboot

reset command

reset help

Used to initialize the terminal This is useful once a program dies leaving a terminal in an abnormal state

restore command

restore help

Used for restoring files from a backup created using dump

return command

return help

Used to exit from a shell function

rev command

rev help

Used to reverse the lines characterwise

rmmod command

rmmod help

Used to remove a module from the kernel

route command

route help

Used when you want to work with the IP/kernel routing table

S

sar command

sar help

screen command

screen help

Provides the ability to launch and use multiple shell sessions from a single ssh session

sudo command

sudo help

script command

script help

Used to make typescript or record all the terminal activities

sdiff command

sdiff help

Used to compare two files and then writes the results to standard output in a side-by-side format

sed command

sed help

Used for finding, filtering, text substitution, replacement and text manipulations like insertion, deletion search etc

select command

select help

Used to create a numbered menu from which a user can select an option

seq command

seq help

Used to generate numbers from FIRST to LAST in steps of INCREMENT

setsid command

setsid help

Used to run a program in a new session

su command

su help

shift command

shift help

Shifts/moves the command line arguments to one position left

showkey command

showkey help

prints to standard output either the scan codes or the key code or the `ascii’ code of each key pressed

shred command

shred help

Used in order to delete a file completely from hard disk

shutdown command

shutdown help

Used to shutdown the system in a safe way

sleep command

sleep help

Used to create a dummy job A dummy job helps in delaying the execution

source command

source help

Used to read and execute the content of a file(generally set of commands), passed as an argument in the current shell script

sort command

sort help

Used to sort a file, arranging the records in a particular order

split command

split help

Used to split large files into smaller files

ssh command

ssh help

Protocol used to securely connect to a remote server/system

strace command

strace help

It is one of the most powerful process monitoring, diagnostic, instructional tool of Linux

stty command

stty help

Used to change and print terminal line settings

sum command

sum help

Used to find checksum and count the blocks in a file

sync command

sync help

Used to synchronize cached writes to persistent storage

T

tac command

tac help

Used to concatenate and print files in reverse

tail command

Tail help

Prints the last N number of data of the given input

tailf command

Tailf help

talkd command

talkd help

tar command

tar help

Used to create Archive and extract the Archive files

taskset command

taskset help

tcpdump command

tcpdump help

tcpslice command

tcpslice help

tcpslice command

tcpslice help

tee command

tee help

telnet command

telnet help

terminator command

terminator help

tftp command

tftp help

tftpd command

tftpd help

tmpwatch command

tmpwatch help

top command

top help

touch command

touch help

touch - update file's timestamp More commonly used for creating files

tput command

tput help

tr command

tr help

It is a command line utility for translating or deleting characters

tracepath command

tracepath help

Used to traces path to destination discovering MTU along this path

traceroute command

traceroute help

Prints the route that a packet takes to reach the host

trep command

trep help

tree command

tree help

tset command

tset help

tty command

tty help

It displays the information related to terminal It basically prints the file name of the terminal connected to standard input

tune2fs command

tune2fs help

tunelp command

tunelp help

type command

type help

U

ul command

ul help

unalias command

unalias help

uname command

uname help

Displays the information about the system

uncompress command

uncompress help

unexpand command

unexpand help

Converts each spaces into tabs writing the produced output to the standard output

unicode_start command

unicode_start help

unicode_stop command

help

uniq command

uniq help

It is a command line utility that reports or filters out the repeated lines in a file

units command

units help

unix2dos command

unix2dos help

unshar command

unshar help

until command

until help

Used to execute a set of commands as long as the final command in the ‘until’ Commands has an exit status which is not zero

uptime command

Uptime help

Used to find out how long the system is active (running)

useradd, userdel commands

useradd help

usermod command

usermod help

usleep command

usleep help

uudecode command

uudecode help

uuencode command

uuencode help

uuidgen command

uuidgen help

V

vi command

A text editor utility.

vidmode command

vidmode help

Set the video mode for a kernel image. Displays current mode value without arguments.

vim command

Vi Improved, a text-based editor which is a successor to vi.

vmstat command

vmstat help

It is a performance monitoring command of the system as it gives the information about processes, memory, paging, block IO, disk and CPU scheduling

vnstat command

vnstat help

Used by system administrators in order to monitor network parameters such as bandwidth consumption or maybe some traffic flowing in or out

W

w command

w help

Used to show who is logged on and what they are doing

wall command

wall help

Displays a message, or the contents of a file, or otherwise its standard input, on the terminals of all currently logged in users

wc command

wc help

Used to find out number of lines, word count, byte and characters count in the files specified in the file arguments

wget command

Wget help

Used to download files from the server even when the user has not logged on to the system and it can work in background without hindering the current process

whatch command

watch help

Used to execute a program periodically, showing output in fullscreen

whatis command

whatis help

which command

which help

Used to locate the executable file associated with the given command by searching it in the path environment variable

while command

while help

Used to repeatedly execute a set of command as long as the COMMAND returns true

who command

who help

Used to get information about currently logged in user on to system

whoami command

whoami help

Displays the username of the current user when this command is invoked

write command

write help

Allows a user to communicate with other users, by copying lines from one user’s terminal to others

X

xargs command

xargs help

Used to build and execute commands from standard input It converts input received from standard input into arguments of a command

xdg-open command

xdg-open help

xinetd command

xinetd help

xz command

xz help

Y

yacc command

yacc help

yes command

yes help

ypbind command

help

ypcat command

help

ypinit command

help

ypmatch command

help

yppasswd command

help

yppasswdd command

help

yppoll command

help

yppush command

help

ypserv command

help

ypset command

help

yptest command

yptest help

ypwhich command

ypwhich help

ypxfr command

ypxfr help

Z

zcat command

zcat help

zcmp command

zcmp help

zdiff command

zdiff help

Used to invoke the diff program on files compressed via gzip

zdump command

zdump help

Used to print the current time in the specified zone or you can say prints the current time in each zonename named on the command line

zforce command

zforce help

zgrep command

zgrep help

Used to search out expressions from a given a file even if it is compressed

zic command

zic help

zip command

zip help

It is a compression and file packaging utility for Unix Each file is stored in single zip {zip-filename} file with the extension zip

zmore command

zmore help

znew command

znew help

get help source: geeksforgeeks