Linux Commands Cheat Sheet: 50 Essential Commands You Need to Know

File Operations

Command	Description	Example
ls	List directory contents	ls -la
cd	Change directory	cd /var/log
pwd	Print working directory	pwd
cp	Copy files	cp file.txt /backup/
mv	Move/rename files	mv old.txt new.txt
rm	Remove files	rm -rf /tmp/cache/
mkdir	Create directory	mkdir -p a/b/c
find	Search for files	find / -name "*.log"
locate	Quick file search	locate nginx.conf
touch	Create empty file	touch file.txt

Text Processing

Command	Description	Example
cat	Display file contents	cat /etc/hosts
less	Paginate file output	less /var/log/syslog
head	Show first lines	head -n 20 file.txt
tail	Show last lines	tail -f /var/log/app.log
grep	Search text patterns	grep -i "error" log.txt
awk	Text processing	awk '{print $1}' file
sed	Stream editor	sed 's/old/new/g' file
wc	Count lines/words	wc -l file.txt
sort	Sort lines	sort -u file.txt
uniq	Remove duplicates	`sort file

Permissions & Ownership

Command	Description	Example
chmod	Change permissions	chmod 755 script.sh
chown	Change owner	chown user:group file
sudo	Run as superuser	sudo apt update
su	Switch user	su - root

Process Management

Command	Description	Example
ps	List processes	`ps aux
top	Process monitor	top
htop	Interactive monitor	htop
kill	Terminate process	kill -9 1234
bg	Resume in background	bg %1
fg	Bring to foreground	fg %1
nohup	Run after logout	nohup ./script.sh &
systemctl	Manage services	systemctl status nginx

Networking

Command	Description	Example
ip	Network configuration	ip addr show
ss	Socket statistics	ss -tlnp
curl	HTTP requests	curl -I https://example.com
wget	Download files	wget https://example.com/file.zip
ping	Test connectivity	ping google.com
traceroute	Trace packet path	traceroute google.com
nmap	Network scanner	nmap -sV 192.168.1.0/24
ssh	Remote login	ssh user@192.168.1.10

System Information

Command	Description	Example
df	Disk usage	df -h
du	Directory size	du -sh /var
free	Memory usage	free -m
uname	System info	uname -a
uptime	System uptime	uptime
journalctl	View logs	journalctl -u nginx

Package Management

Command	Description	Example
apt	Debian/Ubuntu packages	sudo apt install nginx
yum	CentOS/RHEL packages	yum install httpd
dnf	Modern Fedora packages	dnf install git
snap	Snap packages	snap install code --classic

Master these 50 commands and you'll handle 95% of daily Linux tasks. Practice them in a real terminal — repetition builds muscle memory.