Hello everyone, here is a list of all the linux commands I can think of and can be helpful for your usage. Download Linux Command Cheat Sheet PDF Version here.

File Administration

ls [options] [arguments] : List the files in a particular directory or present directory if used without options or arguments
cd [options] directory: change the present directory
ln [options] original file link file : Create links b/w files or b/w directories
ln [options] original file : Create a link to the original file in the present directory
mkdir [options] directory : Make a directory
mv [options] source destination : Move and/or rename files and directories
pwd [option] : prints the current working directory
rm [options] file : Delete files or directories
rmdir [options] directory : Remove empty directories
tar [options] archivename [file(s)] : archive or extract files
chgrp [options] group files: Change group ownership of one or more files & directories
chmod [options]mode files: Change access permissions of one or more files & directories
chown[options] new owner files : Change the ownership of one or more files & directories
cp [options] source destination : Copy files and directories
find [start-point] [search-criteria] [search-term] : find files
gzip [options] filename : compress or expand files
cat [options] [filenames] [-] [filenames] : Display, combine or create new files.
cut [options] file : Cut out sections of each line of a file or files
diff [options] from-file to-file : Display the differences between two files
grep [options] pattern [file] : Search text and match patterns
head [options] filename(s) : List the first part of a specified file
less [options] filename : Display text files
more [options] filename : Display a text file
tail [options] filename(s) : List the last part of a specified file

Processes

crontab [-u user] [-l | -r | -e] : Schedule a task to run at a particular time or interval
kill [options] PID(s) : sends a signal to terminate a process or processes by PID
killall [options] command name : sends a signal to terminate a processes by name
ps [options] : displays a snapshot of the current processes
top [options] : display system and process information in real time

Network

ifconfig [arguments] interface [options] : Configure a network interface
ifconfig [arguments] [interface] : View network interface details
ip [options] object sub-command [parameters] : network configuration tool
netstat [options] : network connection monitoring tool
ping [options] remote server : checks the network connection to a remote server.
curl [options] [URL] : download or upload files to remote servers.
host [options] server : checks a computers IP address from its host-name or the reverse
scp[options][email protected]:directory/[email protected]:directory/filename : securely copy files between computers
sftp [options] [[email protected]] hostname [:directory] : interactively copy files between computers securely
ssh [options] [login name] server : securely access a remote computer.
traceroute [options] host-name : trace the route packets take to network host
wget [options] [URL] : download or upload files from the web non-interactivly.

Miscellaneous

apt-get install package-name : Install a package
apt-get remove package-name : Un-install a package
apt-get update : Update the database of available packages
apt-get upgrade : Upgrade the packages on the system
echo [options] [string(s)] : display text on the screen.
groupadd [options] group : add a group account
clear : clears the terminal screen.
man [options] command : display the reference manual for a command.
modprobe [options] modulename : Load or remove a Linux kernel module
passwd [options] username : change the user password
shutdown [options] [time] [message] : shut down or restart a system.
su [options] [username] : switch to another user.
sudo [options] command : Execute a command as the superuser
usermod [options] username : Modify a users account configuration
useradd [options] username : Add a user account
who [options] : report the users logged onto the system.
whoami [options] : report the current user.

File Systems

fdisk [options] [device] : manipulate partition tables.
mkfs [options] device : format a partition with a file system
mount [options] type device directory : Mount storage onto the file system
umount [options] device and/or directory : Unmount storage from the file system

System Information

date [options] +format : display or set the date / time
du [options] file : display the amount space used in files and directories
free [options] : displays information about free and used memory on the system
df [options] file : display the amount of free space on filesystems.