Linux Commands Cheat Sheet 🐧📚📚

01. ls

This command is used to list the files and directories in the current directory.

Usage:

ls

Output:

Desktop Documents Downloads Music Pictures Videos

02. cd

This command is used to change the directory. You can use cd to change to the home directory. Or, you can use cd .. to move to the parent directory. You can also use cd - to move to the previous directory. You can also specify the path after the cd command to move to that directory. Or,use cd ../.. to move two directories down.You can use cd ~ to move to the home directory. You can also use cd /to move to the root directory. You can also use cd then the directory path to move to that directory.

Usage:

cd

Output:

/home/username

03. pwd

This command is used to print the current working directory. You can use pwd to print the current working directory.

Usage:

pwd

Output:

/home/username

04. touch

This command is used to create a new file. You can use touch then the file name to create a new file.

Usage:

touch file.txt

Output:

file.txt

05. mkdir

This command is used to create a new directory. You can use mkdir then the directory name to create a new directory.

Usage:

mkdir directory

Output:

directory

06. rm

This command is used to remove files or directories. You can use rm then the file name to remove a file. You can also use rm -r then the directory name to remove a directory. Or, rm -rf then the directory name to remove a directory forcefully. You can also use rm -i then the file name to remove a file interactively. You can append sudo before the rm command to remove a file or directory that requires root permission. Remember, the rm command is irreversible.

Usage:

rm file.txt

Output:

If you use the command ls then you will see the file is removed.

07. cp

This command is used to copy files or directories. You can use cp then the source file name and the destination file name to copy a file. You can also use cp -r then the source directory name and the destination directory name to copy a directory. You can also use cp -i then the source file name and the destination file name to copy a file interactively. You can append sudo before the cp command to copy a file or directory that requires root permission.

Usage:

cp file.txt file2.txt

Output:

file2.txt

Usage Number 2:

cp -r directory directory2

Output:

directory2

You will see the files are copied.

08. mv

This command is used to move files or directories. You can use mv then the source file name and the destination file name to move a file. You can also use mv -i then the source file name and the destination file name to move a file interactively. You can append sudo before the mv command to move a file or directory that requires root permission.

Usage:

mv file.txt directory

Output:

directory/file.txt

09. cat

This command is used to display the contents of a file. You can use cat then the file name to display the contents of a file.

Usage:

cat file.txt

Output:

Hello World

If file.txt contains Hello World, then the output will be Hello World. If there is nothing, then the output will be empty.

10. more

This command is used to display the contents of a file one page at a time. You can use more then the file name to display the contents of a file one page at a time. You can use the space key to move to the next page. You can use the Enter key to move to the next line. You can use the q key to quit the display. You can use the b key to move to the previous page.

Usage:

more file.txt

Output:

Hello World

11. less

This command is used to display the contents of a file one page at a time. You can use less then the file name to display the contents of a file one page at a time. You can use the space key to move to the next page. You can use the enter key to move to the next line. You can use the q key to quit the display. You can use the b key to move to the previous page. You can use the / key to search for a pattern in the file. You can use the n key to move to the next occurrence of the pattern. You can use the N key to move to the previous occurrence of the pattern. This command is similar to the more command. But,it is mainly used if the file is so big that no text editor can handle it.

Usage:

less file.txt

Output:

Hello World

If file.txt contains Hello World,then the output will be Hello World. If there is nothing,then the output will be empty.

12. head

This command is used to display the first few lines of a file. You can use head then the file name to display the first few lines of a file. You can also use head -n then the number of lines and the file name to display the first few lines of a file. You can also use head -c then the number of bytes and the file name to display the first few bytes of a file.

Usage:

head file.txt

Output:

This is the headline

If file.txt contains This is the headline as the headline,then the output will be This is the headline. If there is nothing,then the output will be empty.

13. tail

This command is used to display the last few lines of a file. You can use tail then the file name to display the last few lines of a file. You can also use tail -n then the number of lines and the file name to display the last few lines of a file. You can also use tail -c then the number of bytes and the file name to display the last few bytes of a file. You can also use tail -f then the file name to display the last few lines of a file and keep the file open for new lines.

Usage:

tail file.txt

Output:

This is the last line

If file.txt contains This is the last line at the end,then the output will be This is the last line. If there is nothing,then the output will be empty.

14. grep

This command is used to search for a pattern in a file. You can use grep then the pattern and the file name to search for a pattern in a file. You can also use grep -i then the pattern and the file name to search for a pattern in a file case-insensitively. You can also use grep -v then the pattern and the file name to search for a pattern in a file inversely. You can also use grep -c then the pattern and the file name to search for a pattern in a file and display the count of the pattern. You can also use grep -n then the pattern and the file name to search for a pattern in a file and display the line numbers of the pattern. You can also use grep -l then the pattern and the file name to search for a pattern in a file and display the file names containing the pattern. You can also use grep -r then the pattern and the directory name to search for a pattern in a directory recursively.

Usage:

grep "pattern" file.txt

Output:

pattern

If file.txt contains pattern 1 or more times, then the output will be pattern. If there is nothing, then the output will be empty.

15. find

This command is used to find files or directories. You can use find then the directory name to find files or directories in a directory. You can also use find -name then the file name to find files or directories with the specified name. You can also use find -iname then the file name to find files or directories with the specified name case-insensitively. You can also use find -type then the file type to find files or directories with the specified type. You can also use find -empty to find empty files or directories. You can also use find -size then the file size to find files or directories with the specified size. You can also use find -exec then the command to execute the command on the found files or directories.

Usage:

find directory

Output:

directory

If the directory exists, then the output will be the directory name. If there is nothing, then the output will be empty.

16. whereis

This command is used to find the binary, source, and manual page files for a command. You can use whereis then the command name to find the binary, source, and manual page files for a command.

Usage:

whereis ls

Output:

ls: /bin/ls

17. which

This command is used to find the location of a command. You can use which then the command name to find the location of a command.

Usage:

which ls

Output:

/bin/ls

18. man

This command is used to display the manual page of a command. You can use man then the command name to display the manual page of a command. You can use the space key to move to the next page. You can use the enter key to move to the next line. You can use the q key to quit the display. You can use the / key to search for a pattern in the manual page. You can use the n key to move to the next occurrence of the pattern. You can use the N key to move to the previous occurrence of the pattern.

Usage:

man brew

Output:

 BREW(1) Homebrew Manual BREW(1) NAME brew - The Missing Package Manager for macOS SYNOPSIS brew command [options] [formula] brew help [command] brew home brew --version brew --prefix brew --cache brew --cellar brew --repository brew update brew list [--full-name] brew search [text|/text/] brew install formula brew uninstall formula brew info [formula] brew deps formula brew uses formula brew outdated brew upgrade [formula] brew pin formula brew unpin formula brew list [formula] brew cleanup brew doctor brew missing brew link formula brew unlink formula brew switch formula brew list --versions formula brew cat formula brew edit formula brew create [URL [--no-fetch]] brew home formula brew options formula brew install formula brew fetch [formula] brew update brew upgrade brew uninstall formula brew pin formula brew unpin formula brew tap user/repo brew tap --repair brew tap --list brew tap --prune brew tap --search brew tap --list-official brew tap --list-pinned brew tap --list-unpinned brew tap --list-versions brew tap --list-pinned-versions brew tap --list-unpinned-versions brew tap --list-pinned-official brew tap --list-unpinned-official brew tap --list-pinned-user brew tap --list-unpinned-user brew tap --list-pinned-user-versions brew tap --list-unpinned-user-versions brew tap --list-pinned-user-official 

And, it will show you a lot more. I am not going to show you the whole manual page. This manual page is for homebrew. If you want to see the manual page of a command, then use man then the command name.

01. chmod

This command is used to change the permissions of a file or directory. You can use chmod then the permissions and the file name to change the permissions of a file or directory. You can also use chmod -R then the permissions and the directory name to change the permissions of a directory recursively. You can also use chmod u+x then the file name to add execute permission to the owner of the file. You can also use chmod g+x then the file name to add execute permission to the group of the file. You can also use chmod o+x then the file name to add execute permission to others. You can also use chmod a+x then the file name to add execute permission to all. You can also use chmod u-x then the file name to remove execute permission from the owner of the file. You can also use chmod g-x then the file name to remove execute permission from the group of the file. You can also use chmod o-x then the file name to remove execute permission from others. You can also use chmod a-x then the file name to remove execute permission from all. You can also use chmod u=rwx then the file name to set read, write, and execute permissions for the owner of the file. You can also use chmod g=rwx then the file name to set read, write, and execute permissions for the group of the file. You can also use chmod o=rwx then the file name to set read, write, and execute permissions for others. You can also use chmod a=rwx then the file name to set read, write, and execute permissions for all. You can also use chmod 777 then the file name to set read, write, and execute permissions for all. You can also use chmod 755 then the file name to set read, write, and execute permissions for the owner and read and execute permissions for the group and others. You can also use chmod 644 then the file name to set read and write permissions for the owner and read permissions for the group and others. You can also use chmod 600 then the file name to set read and write permissions for the owner and no permissions for the group and others. You can also use chmod 666 then the file name to set read and write permissions for all. You can also use chmod 444 then the file name to set read permissions for all. You can also use chmod 400 then the file name to set read permissions for the owner and no permissions for the group and others. You can also use chmod 200 then the file name to set write permissions for the owner and no permissions for the group and others. You can also use chmod 100 then the file name to set execute permissions for the owner and no permissions for the group and others. You can also use chmod 000 then the file name to set no permissions for all.

Usage:

chmod 777 file.txt

Output:

file.txt

If you use the command ls -l then you will see the permissions are changed.

02. chown

This command is used to change the owner of a file or directory. You can use chown then the owner name and the file name to change the owner of a file or directory. You can also use chown -R then the owner name and the directory name to change the owner of a directory recursively. You can also use chown owner:group then the owner name, group name, and the file name to change the owner and group of a file or directory. You can also use chown -R owner:group then the owner name, group name, and the directory name to change the owner and group of a directory recursively.

Usage:

chown owner file.txt

Output:

file.txt

If you use the command ls -l then you will see the owner is changed.

03. whoami

This command is used to print the current user. You can use whoami to print the current user.

Usage:

whoami

Output:

username

04. date

This command is used to print the current date and time. You can use date to print the current date and time. The format will be Day, Date, Month, Year, Time, Timezone.

Usage:

date

Output:

Sun 10 Oct 2021 10:10:10 PM IST

05. cal

This command is used to print the calendar of the current month. You can use cal to print the calendar of the current month.

Usage:

cal

Output:

 October 2021 Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 

06. clear

This command is used to clear the terminal. You can use clear to clear the terminal. You can do ctrl+l to clear the terminal too.

Usage:

clear

Output:

You will see the terminal is cleared.

07. echo

This command is used to print a message. You can use echo then the message to print a message. You can also use ```echo -e``` then the message to print a message with escape characters interpreted. You can also use ```echo -n``` then the message to print a message without a newline.

Usage:

echo "Hello World"

Output:

Hello World

08. uname

This command is used to print the system information. You can use uname to print the system information. You can also use uname -a to print all the system information. You can also use uname -s to print the system name. You can also use uname -n to print the network node hostname. You can also use uname -r to print the kernel release. You can also use uname -v to print the kernel version. You can also use uname -m to print the machine hardware name. You can also use uname -p to print the processor type. You can also use uname -i to print the hardware platform. You can also use uname -o to print the operating system.

Usage:

uname

Output:

Linux

09. uptime

This command is used to print the uptime of the system. You can use uptime to print the uptime of the system.

Usage:

uptime

Output:

10:10:10 up 10 days, 10:10, 10 users, load average: 1.10, 1.10, 1.10

If the system is up for 10 days,10 hours,10 minutes, then the output will be 10:10:10 up 10 days, 10:10, 10 users, load average: 1.10, 1.10, 1.10. If there is nothing, then the output will be empty.

10. w

This command is used to print the users who are currently logged in and what they are doing. You can use w to print the users who are currently logged in and what they are doing.

Usage:

w

Output:

 10:10:10 up 10 days, 10:10, 10 users, load average: 1.10, 1.10, 1.10 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT username tty1 :0 10:10 10:10 10:10 10:10 -bash 

If the user is logged in and is doing something, then the output will be the user's information. If there is nothing, then the output will be empty.

11. who

This command is used to print the users who are currently logged in. You can use who to print the users who are currently logged in.

Usage:

who

Output:

username tty1 2021-10-10 10:10 (:0)

If the user is logged in, then the output will be the user's information. If there is nothing, then the output will be empty.

12. ps

This command is used to print the currently running processes. You can use ps to print the currently running processes. You can also use ps -e to print all the processes. You can also use ps -f to print the full-format listing. You can also use ps-l to print the long-format listing. You can also use ps -u then the username to print the processes of the user. You can also use ps -aux to print all the processes in full-format listing.

Usage:

ps

Output:

 PID TTY TIME CMD 123 tty1 00:00:00 bash 

If the process is running, then the output will be the process information. It will also show system running processes.

13. kill

This command is used to kill a process. You can use kill then the process ID to kill a process. You can also use kill -9 then the process ID to kill a process forcefully. You can also use kill -l to list all the signals.

Usage:

kill 123

Output:

If the process is killed, then the output will be empty.

14. killall

This command is used to kill all processes by name. You can use killall then the process name to kill all processes by name. You can also use killall -9 then the process name to kill all processes by name forcefully.

Usage:

killall bash

Output:

If the process is killed, then the output will be empty.

15. pkill

This command is used to kill a process by name. You can use pkill then the process name to kill a process by name. You can also use pkill -9 then the process name to kill a process by name forcefully.

Usage:

pkill bash

Output:

If the process is killed, then the output will be empty.

16. pgrep

This command is used to find the process ID by name. You can use pgrep then the process name to find the process ID by name.

Usage:

pgrep bash

Output:

123

If the process is found, then the output will be the process ID. If there is nothing, then the output will be empty.

17. top

This command is used to display the dynamic real-time view of a running system. You can use top to display the dynamic real-time view of a running system. You can use the q key to quit the display.

Usage:

top

Output:

 top - 10:10:10 up 10 days, 10:10, 10 users, load average: 1.10, 1.10, 1.10 Tasks: 123 total, 1 running, 122 sleeping, 0 stopped, 0 zombie %Cpu(s): 10.0 us, 10.0 sy, 10.0 ni, 10.0 id, 10.0 wa, 10.0 hi, 10.0 si, 10.0 st MiB Mem : 1000.0 total, 100.0 free, 900.0 used, 100.0 buff/cache PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 123 username 20 0 100.0m 10.0m 10.0m S 10.0 1.0 10:10.10 bash 

If the system is running, then the output will be the system information. If there is nothing, then the output will be empty.

18. htop

This command is used to display the dynamic real-time view of a running system. You can use htop to display the dynamic real-time view of a running system. You can use the q key to quit the display.

Usage:

htop

Output:

19. free

This command is used to display the amount of free and used memory in the system. You can use free to display the amount of free and used memory in the system.

Usage:

free

Output:

 total used free shared buff/cache available Mem: 1000.0 900.0 100.0 10.0 100.0 100.0 Swap: 1000.0 900.0 100.0 

20. df

This command is used to display the amount of disk space available on the file system. You can use df to display the amount of disk space available on the file system. You can also use df -h to display the amount of disk space available on the file system in human-readable format. You can also use df -T to display the amount of disk space available on the file system with the file system type.

Usage:

df

Output:

 Filesystem 1K-blocks Used Available Use% Mounted on udev 1000000 0 1000000 0% /dev tmpfs 1000000 100 100000 1% /run /dev/sda1 1000000 10000 900000 1% / tmpfs 1000000 100 100000 1% /dev/shm tmpfs 1000000 100 100000 1% /run/lock tmpfs 1000000 100 100000 1% /sys/fs/cgroup /dev/sda2 1000000 10000 900000 1% /home tmpfs 1000000 100 100000 1% /run/user/1000