Linux provides a diverse range of commands, bellow is a list of the most relevant commands.

alias

Gives a specific name to a command or sequence of commands.

alias cls=clear
alias pf="ps -e | grep PATH

exit

Exit an ssl session.

find

Finds file location.

find . -name *ones*
find . -type f -name *ones*
find . -iname *wild*

. matches the current folder. -name *ones* the file name contains the string ‘ones’, -iname not a case sensitive search.

finger

Get user information.

free

Current memory usage.

free -h

grep

Searches lines that contains a specific string.

grep train *.txt

groups

Get a user’s group.

groups ayoub

gzip

Files compression.

gzip -k core.c

-k for keep.

head

Returns the first 10 lines of a file.

head -n 5 core.c

-n for more lines.

history

Shows the history of the used commands.

history
!19
!!

!19 use the command 19 displayed in the history. !! use the last command.

kill

Terminate a process.

ps -e | grep shutter
kill 1692

less

 View files without opening an editor.

less core.c

ls

Lists the files and folders in a specific directory.

ls -lha

-l for long files, h human friendly, a hidden files.

man

Displays user manual pages in less mode.

man chown

mkdir

Creates a new directory.

mkdir -p quotes/yearly/2019

-p for parents (creates parents too).

mv

Moves files and directories.

mv ~/Documents/manuals/Apache.pdf ./The_Shadows_Apache.pdf

passwd

Change user password.

sudo passwd ayoub

ping

Verifies current network connectivity with another network.

ping -c 3 -a 8.8.8.8

-c for attempts, -a to hear a ping.

ps

Lists current running processes

ps -u dave | less
ps -e | less

-u for a particular user, -e for every process.

pwd

Current working directory.

shutdown

shutdown +15 Shutting down in 15 minutes!
shutdown -c

-c to cancel shutdown.

SSH

Allows to establish a connection to a remote Linux computer.

ssh ayoub@192.168.4.23

sudo

For actions that require root access.

sudo passwd ayoub

tail

List the first 10 (default) or n lines of a file.

tail -n 5 core.c

tar

Creates a tarball archive file.

tar -cvzf songs.tar.gz ayoub/

-c for create, -v for verbose, -f for file, z (gzip) for compression. j (bzip2) for superior compression algorithm.

top

Displays the current machine realtime data and information.

uname

Displays current system information. -a for all, -s -r -v for kernel name, release, and version.

whoami

Determines whether you’re logged or not.

w

Displays current logged users.