Basic Linux Commands with Examples

In this Linux cheat sheet, we cover essential commands ranging from basic to advanced. Whether you're a beginner or an experienced professional, this cheat sheet can help you work more efficiently with the Linux operating system.

1. File and Directory Operations Commands

File and directory operations are fundamental in working with Linux. Here are some commonly used commands:

Command	Description	Options	Examples
ls	List files and directories	-l: Long format listing -a: Include hidden files -h: Human-readable file sizes	ls -l: Displays files with detailed information ls -a: Includes hidden files ls -lh: Shows file sizes in a human-readable format
cd	Change directory	N/A	cd /path/to/directory: Changes to the specified directory
pwd	Print working directory	N/A	pwd: Displays the current working directory
mkdir	Create a new directory	N/A	mkdir my_directory: Creates a directory named "my_directory"
rm	Remove files and directories	-r: Remove directories recursively -f: Force removal without confirmation	rm file.txt: Deletes "file.txt" rm -r my_directory: Deletes "my_directory" and its contents rm -f file.txt: Force deletes "file.txt"
cp	Copy files and directories	-r: Copy directories recursively	cp file.txt destination: Copies "file.txt" to destination cp -r directory destination: Copies directory to destination
mv	Move/rename files and directories	N/A	mv file.txt new_name.txt: Renames "file.txt" to "new_name.txt" mv file.txt directory: Moves "file.txt" to the specified directory
touch	Create an empty file or update file timestamps	N/A	touch file.txt: Creates an empty file named "file.txt"
cat	View the contents of a file	N/A	cat file.txt: Displays the contents of "file.txt"
head	Display the first few lines of a file	-n: Specify the number of lines to display	head file.txt: Displays the first 10 lines head -n 5 file.txt: Shows the first 5 lines
tail	Display the last few lines of a file	-n: Specify the number of lines to display	tail file.txt: Shows the last 10 lines tail -n 5 file.txt: Displays the last 5 lines
ln	Create links between files	-s: Create symbolic (soft) links	ln -s source_file link_name: Creates a symbolic link named "link_name" pointing to "source_file"
find	Search for files and directories	-name: Search by filename -type: Search by file type	find /path/to/search -name "*.txt": Finds all ".txt" files in the specified directory

2. File Permission Commands

File permissions in Linux control access to files and directories. Here are commands for managing file permissions:

Command	Description	Options	Examples
chmod	Change file permissions	u: User/owner permissions g: Group permissions o: Other permissions +: Add permissions -: Remove permissions =: Set permissions explicitly	chmod u+rwx file.txt: Grants read, write, and execute permissions to the owner of "file.txt"
chown	Change file ownership	N/A	chown user file.txt: Changes the owner of "file.txt" to "user"
chgrp	Change group ownership	N/A	chgrp group file.txt: Changes the group ownership of "file.txt" to "group"
umask	Set default file permissions	N/A	umask 022: Sets default file permissions to rw-r--r--

3. File Compression and Archiving Commands

These commands help in file compression and archiving.

Command	Description	Options	Examples
tar	Create or extract archive files	-c: Create a new archive -x: Extract files from an archive -f: Specify archive file name -v: Verbose mode -z: Compress with gzip -j: Compress with bzip2	tar -czvf archive.tar.gz files/: Creates a compressed archive
gzip	Compress files	-d: Decompress files	gzip file.txt: Compresses "file.txt" to "file.txt.gz"
zip	Create compressed zip archives	-r: Recursively include directories	zip archive.zip file1.txt file2.txt: Creates "archive.zip"

4. Process Management Commands

Linux process management commands monitor and control processes.

Command	Description	Options	Examples
ps	Display running processes	-aux: Show all processes	ps aux: Shows all processes with detailed info
top	Monitor system processes in real-time	N/A	top: Displays real-time system processes
kill	Terminate a process	-9: Forcefully kill a process	kill PID: Terminates the process with the specified ID
pkill	Terminate processes by name	N/A	pkill process_name: Kills all processes with the given name
pgrep	List processes by name	N/A	pgrep process_name: Lists all processes with the name

5. System Information Commands

These commands display system information.

Command	Description	Options	Examples
uname	Print system information	-a: All system information	uname -a: Displays all system information
whoami	Show the current username	N/A	whoami: Displays the current username
df	Show disk space usage	-h: Human-readable sizes	df -h: Displays disk space in a human-readable format
du	Estimate file and directory sizes	-h: Human-readable sizes -s: Display total size only	du -sh directory/: Shows total size of the specified directory
free	Display memory usage	-h: Human-readable sizes	free -h: Shows memory usage in a human-readable format
uptime	Show system uptime	N/A	uptime: Displays current system uptime
lscpu	Display CPU information	N/A	lscpu: Shows detailed CPU information
lspci	List PCI devices	N/A	lspci: Lists PCI devices
lsusb	List USB devices	N/A	lsusb: Lists USB devices

6. Networking Commands

Use these commands to manage network connections.

Command	Description	Examples
ifconfig	Display network interface information	ifconfig: Displays details of network interfaces
ping	Send ICMP echo requests to a host	ping google.com: Checks connectivity to "google.com"
netstat	Display network connections and statistics	netstat -tuln: Shows TCP and UDP connections
ss	Display network socket information	ss -tuln: Shows listening TCP and UDP connections
ssh	Securely connect to a remote server	ssh user@hostname: Initiates an SSH connection
scp	Securely copy files between hosts	scp file.txt user@hostname:/path/to/destination: Copies "file.txt" to remote host
wget	Download files from the web	wget http://example.com/file.txt: Downloads "file.txt"
curl	Transfer data to or from a server	curl http://example.com: Retrieves a webpage's content

7. IO Redirection Commands

These commands handle input/output redirection in Linux.

Command	Description	Examples
cmd < file	Input of cmd is taken from file	cat < file.txt: Displays the content of "file.txt"
cmd > file	Standard output (stdout) is redirected to file	echo "Hello" > output.txt: Writes "Hello" to "output.txt"
cmd 2> file	Error output (stderr) is redirected to file	ls non_existent_file 2> error.log: Redirects error to "error.log"
cmd &> file	Redirects both stdout and stderr to file	ls &> output.log: Redirects all output to "output.log"
cmd >> file	Appends stdout to a file	echo "New line" >> file.txt: Appends "New line" to "file.txt"

8. Environment Variable Commands

Set and display environment variables.

Command	Description	Examples
export VARIABLE=value	Set an environment variable	export PATH=/usr/local/bin:$PATH: Adds a directory to the PATH
echo $VARIABLE	Display the value of an environment variable	echo $PATH: Displays the PATH environment variable
env	List all environment variables	env: Displays all environment variables
unset VARIABLE	Remove an environment variable	unset PATH: Removes the PATH variable
export -p	Show all exported environment variables	export -p: Lists all exported variables
env VAR1=value COMMAND	Set an environment variable for a specific command	env VAR1=value command: Runs a command with modified environment variables

9. User Management Commands

Manage user accounts and groups.

Command	Description	Examples
who	Show who is currently logged in	who: Displays the current logged-in users
sudo adduser username	Create a new user	sudo adduser john: Creates a new user named "john"
finger	Display information about users	finger: Displays user details
last	Show the recent login history	last: Displays login history
sudo userdel -r username	Delete a user account	sudo userdel -r john: Deletes the user "john" and their files
su - username	Switch to another user account	su - john: Switches to the "john" user account
sudo usermod -a -G GROUPNAME USERNAME	Add user to a group	sudo usermod -a -G admin john: Adds "john" to the "admin" group

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10. Shortcuts Commands

There are many shortcuts commands in Linux that can help you be more productive. Here are a few of the most common ones:

10.1: Bash Shortcuts Commands

Navigation	Description	Editing	Description	History	Description
Ctrl + A	Move to the beginning of the line.	Ctrl + U	Cut/delete from the cursor position to the beginning of the line.	Ctrl + R	Search command history (reverse search).
Ctrl + E	Move to the end of the line.	Ctrl + K	Cut/delete from the cursor position to the end of the line.	Ctrl + G	Escape from history search mode.
Ctrl + B	Move back one character.	Ctrl + W	Cut/delete the word before the cursor.	Ctrl + P	Go to the previous command in history.
Ctrl + F	Move forward one character.	Ctrl + Y	Paste the last cut text.	Ctrl + N	Go to the next command in history.
Alt + B	Move back one word.	Ctrl + L	Clear the screen.	Ctrl + C	Terminate the current command.
Alt + F	Move forward one word.

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10.2: Nano Shortcuts Commands

File Operations	Description	Navigation	Description	Editing	Description	Search and Replace	Description
Ctrl + O	Save the file.	Ctrl + Y	Scroll up one page.	Ctrl + K	Cut/delete from the cursor position to the end of the line.	Ctrl + W	Search for a string in the text.
Ctrl + X	Exit Nano (prompt to save if modified).	Ctrl + V	Scroll down one page.	Ctrl + U	Uncut/restore the last cut text.	Alt + W	Search and replace a string in the text.
Ctrl + R	Read a file into the current buffer.	*Alt + *	Go to a specific line number.	Ctrl + 6	Mark a block of text for copying or cutting.	Alt + R	Repeat the last search.
Ctrl + J	Justify the current paragraph.	Alt + ,	Go to the beginning of the current line.	Ctrl + K	Cut/delete the marked block of text.
		Alt + .	Go to the end of the current line.	Alt + 6	Copy the marked block of text.

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10.3: VI Shortcuts Commands

Command	Description
cw	Change the current word. Deletes from the cursor position to the end of the current word and switches to insert mode.
dd	Delete the current line.
x	Delete the character under the cursor.
R	Enter replace mode. Overwrites characters starting from the cursor position until you press the Escape key.
o	Insert a new line below the current line and switch to insert mode.
u	Undo the last change.
s	Substitute the character under the cursor and switch to insert mode.
dw	Delete from the cursor position to the beginning of the next word.
D	Delete from the cursor position to the end of the line.
4dw	Delete the next four words from the cursor position.
A	Switch to insert mode at the end of the current line.
S	Delete the current line and switch to insert mode.
r	Replace the character under the cursor with a new character entered from the keyboard.
i	Switch to insert mode before the cursor.
3dd	Delete the current line and the two lines below it.
ESC	Exit from insert or command-line mode and return to command mode.
U	Restore the current line to its original state before any changes were made.
~	Switch the case of the character under the cursor.
a	Switch to insert mode after the cursor.
C	Delete from the cursor position to the end of the line and switch to insert mode.

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10.4: Vim Shortcuts Commands

Normal Mode

Command	Description
i	Enter insert mode at the current cursor position.
x	Delete the character under the cursor.
dd	Delete the current line.
yy	Copy the current line.
p	Paste the copied or deleted text below the current line.
u	Undo the last change.
Ctrl + R	Redo the last undo.
:w	Save the file.
:q	Quit Vim.
:q!	Quit Vim without saving changes.
:wq or :x	Save and quit Vim.
:s/old/new/g	Replace all occurrences of “old” with “new” in the file.
:set nu or :set number	Display line numbers.

Command Mode

Command	Description
:w	Save the file.
:q	Quit Vim.
:q!	Quit Vim without saving changes.
:wq or :x	Save and quit Vim.

Visual Mode

Command	Description
v	Enter visual mode to select text.
y	Copy the selected text.
d	Delete the selected text.
p	Paste the copied or deleted text.

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11. tmux - Terminal Multiplexer

tmux is a terminal multiplexer that allows you to manage multiple terminal sessions within one window. It’s great for running multiple programs simultaneously and for managing long-running processes.

Basic tmux Commands

Command	Description	Examples
tmux	Start a new tmux session	tmux: Starts a new tmux session
tmux new-session -s session_name	Start a new tmux session with a specific name	tmux new-session -s my_session: Starts a new session named "my_session"
tmux attach -t session_name	Attach to an existing tmux session	tmux attach -t my_session: Attaches to the session named "my_session"
tmux ls	List all tmux sessions	tmux ls: Lists all available tmux sessions
tmux kill-session -t session_name	Kill a specific tmux session	tmux kill-session -t my_session: Kills the "my_session" tmux session
tmux detach	Detach from the current tmux session	Press Ctrl + b, then d: Detaches from the current session
tmux kill-session	Kill the current tmux session	tmux kill-session: Kills the current session

Window and Pane Management

• Windows: Each tmux session can have multiple windows (like tabs in a browser).
• Panes: Each window can be split into multiple panes (like dividing your terminal screen).

Command	Description	Examples
Ctrl + b c	Create a new window	Ctrl + b c: Creates a new window in the current session
Ctrl + b n	Switch to the next window	Ctrl + b n: Switches to the next window
Ctrl + b p	Switch to the previous window	Ctrl + b p: Switches to the previous window
Ctrl + b 0-9	Switch to a specific window	Ctrl + b 2: Switches to window 2
Ctrl + b w	List all windows	Ctrl + b w: Lists all windows in the session
Ctrl + b %	Split the current window vertically	Ctrl + b %: Splits the window into two vertical panes
Ctrl + b "	Split the current window horizontally	Ctrl + b ": Splits the window into two horizontal panes
Ctrl + b o	Switch between panes	Ctrl + b o: Moves to the next pane
Ctrl + b x	Close the current pane	Ctrl + b x: Closes the current pane
Ctrl + b {	Move the current pane left	Ctrl + b {: Moves the current pane to the left
Ctrl + b }	Move the current pane right	Ctrl + b }: Moves the current pane to the right

Session and Window Management

Command	Description	Examples
Ctrl + b d	Detach from the session	Ctrl + b d: Detaches from the session and leaves it running in the background
Ctrl + b &	Close the current window	Ctrl + b &: Closes the current window
Ctrl + b ,	Rename the current window	Ctrl + b ,: Renames the current window to a new name
Ctrl + b s	List all sessions	Ctrl + b s: Lists all active tmux sessions
Ctrl + b l	List the last window	Ctrl + b l: Switches to the last active window

Resizing Panes

You can resize tmux panes to allocate more space for one particular pane.

Command	Description	Examples
Ctrl + b :	Enter command mode	Ctrl + b :: Enter command mode to type tmux commands
resize-pane -D	Resize pane down	Ctrl + b :resize-pane -D: Shrinks the pane downward
resize-pane -U	Resize pane up	Ctrl + b :resize-pane -U: Shrinks the pane upward
resize-pane -L	Resize pane left	Ctrl + b :resize-pane -L: Shrinks the pane left
resize-pane -R	Resize pane right	Ctrl + b :resize-pane -R: Shrinks the pane right

Saving and Restoring Sessions

You can save your tmux sessions and restore them later.

Command	Description	Examples
tmux save-buffer /path/to/file	Save the buffer contents to a file	tmux save-buffer output.txt: Saves the buffer to a file named "output.txt"
tmux load-buffer /path/to/file	Load content from a file into the buffer	tmux load-buffer output.txt: Loads content from "output.txt" into the tmux buffer

Copy and Paste Mode

You can enter copy mode in tmux to scroll through the terminal output and copy text.

Command	Description	Examples
Ctrl + b [	Enter copy mode	Ctrl + b [: Enter copy mode
Up/Down Arrow	Scroll through the terminal output	Use the arrow keys to scroll through the terminal
Space	Start selection	Space: Starts selecting text
Enter	Copy selected text	Enter: Copies the selected text
Ctrl + b ]	Paste the copied text	Ctrl + b ]: Pastes the copied text into the current pane

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These are some of the basic and advanced tmux commands that will help you get started with terminal multiplexing. You can create, manage, and navigate between multiple terminal sessions with ease, making tmux an invaluable tool for anyone working in the terminal.

Conclusion

In conclusion, Linux is a widely used operating system for development, and as a developer, you should have knowledge of Linux and its basic commands. In this Cheat Sheet, we covered all commands like creating directories, file compression and archiving, process management, system information, networking, and more. In addition to that, this Linux Cheat Sheet is organized and categorized, making it easy for developers to quickly find the commands they need for specific use cases. By utilizing this resource, developers can enhance their productivity and efficiency in working with Linux, leading to smoother and more successful development projects.