Linux Commands

Linux uses a command-line interface (CLI) for system management, file operations, and network administration. Below are essential Linux commands for beginners.

File & Directory Commands

Command	Description	Example
ls	Lists files in a directory	ls /home
ls -l	Lists files in detail	ls -l
cd	Changes directory	cd Documents
cd ..	Moves up one level	cd ..
pwd	Displays current directory	pwd
mkdir	Creates a new directory	mkdir NewFolder
rmdir	Deletes an empty directory	rmdir OldFolder
rm -r	Deletes a directory & files	rm -r FolderName

File Management Commands

Command	Description	Example
touch	Creates an empty file	touch file.txt
cp	Copies a file	cp file1.txt /backup/
mv	Moves or renames a file	mv file1.txt Documents/
rm	Deletes a file	rm file.txt
cat	Displays file content	cat file.txt
nano	Opens file in Nano editor	nano file.txt
head	Displays first 10 lines of a file	head file.txt
tail	Shows last 10 lines of a file	tail file.txt

User & Permission Commands

Command	Description	Example
who	Lists logged-in users	who
id	Displays user ID (UID, GID)	id
chmod	Changes file permissions	chmod 755 file.sh
chown	Changes file ownership	chown user:group file.txt
passwd	Changes user password	passwd

Process Management Commands

Command	Description	Example
ps	Shows running processes	ps aux
top	Displays system resource usage	top
kill	Kills a process	kill PID
pkill	Kills a process by name	pkill firefox
htop	Interactive process manager	htop (install required)