50 Most Useful Linux Commands 🐧

1. System Information

Command	Description	Example
uname -a	Displays system information	uname -a
hostname	Shows the system’s hostname	hostname
lsb_release -a	Shows Linux distribution info	lsb_release -a
uptime	Shows how long the system has been running	uptime
top	Displays running processes in real-time	top
htop	Interactive version of top (needs install)	htop
free -h	Displays memory usage	free -h
df -h	Shows disk usage in human-readable format	df -h
du -sh	Shows total disk usage of a directory	du -sh /home
cat /proc/cpuinfo	Displays CPU information	cat /proc/cpuinfo

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2. File and Directory Management

Command	Description	Example
ls	Lists files and directories	ls -l
cd	Changes directory	cd /var/log
pwd	Prints current working directory	pwd
mkdir	Creates a new directory	mkdir myfolder
rmdir	Removes an empty directory	rmdir oldfolder
rm	Removes files or directories	rm file.txt, rm -rf folder/
cp	Copies files or directories	cp file1.txt /home/user/
mv	Moves or renames files	mv old.txt new.txt
touch	Creates an empty file	touch newfile.txt
find	Searches for files or directories	find / -name "*.txt"

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3. File Viewing and Editing

Command	Description	Example
cat	Displays file content	cat file.txt
less	Views file content one page at a time	less file.txt
head	Shows first 10 lines of a file	head file.txt
tail	Shows last 10 lines of a file	tail -f log.txt
nano	Opens text editor	nano file.txt
vi or vim	Opens VI editor	vi file.txt
grep	Searches for text inside files	grep "error" log.txt
sort	Sorts lines in a file	sort names.txt
uniq	Removes duplicate lines	uniq names.txt
wc	Counts lines, words, characters	wc -l file.txt

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4. Permissions and Ownership

Command	Description	Example
chmod	Changes file permissions	chmod 755 script.sh
chown	Changes file owner and group	chown user:group file.txt
whoami	Shows current user	whoami
id	Displays user ID and group ID	id
sudo	Runs command as superuser	sudo apt update

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5. Networking Commands

Command	Description	Example
ping	Checks connectivity to a host	ping google.com
ifconfig	Shows network interfaces (deprecated)	ifconfig
ip addr	Shows network configuration	ip addr
netstat -tuln	Lists open ports	netstat -tuln
ss -tuln	Modern replacement for netstat	ss -tuln
curl	Transfers data from URLs	curl https://example.com
wget	Downloads files from web	wget http://example.com/file.zip
scp	Copies files over SSH	scp file.txt user@remote:/path
ssh	Connects to remote server via SSH	ssh user@ipaddress
traceroute	Shows route packets take to host	traceroute google.com

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6. Package Management

Command	Description	Example
apt update	Updates package lists (Debian/Ubuntu)	sudo apt update
apt upgrade	Upgrades all packages	sudo apt upgrade
apt install	Installs a package	sudo apt install nginx
apt remove	Removes a package	sudo apt remove nginx
yum install	Installs package (RHEL/CentOS)	sudo yum install httpd

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7. Process and Job Management

Command	Description	Example
ps	Displays running processes	ps aux
kill	Kills a process by PID	kill 1234
killall	Kills all processes by name	killall firefox
bg	Resumes job in background	bg
fg	Brings job to foreground	fg
jobs	Lists background jobs	jobs
nice	Sets process priority	nice -n 10 command
top	Real-time process view	top
htop	Interactive process monitor	htop

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8. Compression and Archiving

Command	Description	Example
tar	Archives files	tar -cvf archive.tar folder/
tar -xvf	Extracts archive	tar -xvf archive.tar
gzip	Compresses files	gzip file.txt
gunzip	Decompresses files	gunzip file.txt.gz
zip	Creates zip file	zip archive.zip file1 file2
unzip	Extracts zip file	unzip archive.zip

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9. Disk and File System Management

Command	Description	Example
mount	Mounts a filesystem	mount /dev/sdb1 /mnt
umount	Unmounts filesystem	umount /mnt
fsck	Checks and repairs file system	fsck /dev/sda1
blkid	Shows block device info	blkid
lsblk	Lists block devices	lsblk

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10. Time and Scheduling

Command	Description	Example
date	Displays current date/time	date
cal	Shows calendar	cal
crontab -e	Edits scheduled cron jobs	crontab -e
at	Runs commands at a specific time	at 5pm

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11. System Shutdown and Reboot

Command	Description	Example
shutdown	Shuts down system	sudo shutdown now
reboot	Reboots system	sudo reboot
halt	Stops all processes	sudo halt
logout	Logs out current user	logout

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Bonus Commands (Hidden Gems)

Command	Description	Example
history	Shows command history	history
alias	Creates command shortcuts	alias ll='ls -la'
echo	Prints text to terminal	echo "Hello Linux"
man	Displays manual for a command	man ls
clear	Clears terminal screen	clear

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Final Thoughts

Learning these Linux commands helps you:

• Work faster with terminal automation
• Troubleshoot systems like a pro
• Manage files, users, and networks with ease

Pro Tip: Combine commands using pipes (|) and logical operators (&&, ||) to perform complex tasks efficiently.
Example:

ps aux | grep nginx && echo "Nginx is running!"

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