Linux Terminal Commands Cheatsheet

A comprehensive reference for essential Linux terminal commands organized by category.

File & Directory Operations

Command	Description	Example
ls	List directory contents	ls
ls -l	Long format with permissions, size, date	ls -l /var/log
ls -la	Include hidden files in long format	ls -la ~
ls -lh	Human-readable file sizes	ls -lh *.tar.gz
ls -lS	Sort by file size (largest first)	ls -lS /tmp
ls -lt	Sort by modification time (newest first)	ls -lt
ls -R	List recursively into subdirectories	ls -R src/
cd <dir>	Change directory	cd /etc/nginx
cd ..	Go up one directory	cd ../..
cd ~ or cd	Go to home directory	cd ~
cd -	Go to previous directory	cd -
pwd	Print current working directory	pwd
mkdir <dir>	Create a directory	mkdir projects
mkdir -p <path>	Create nested directories	mkdir -p a/b/c
rmdir <dir>	Remove an empty directory	rmdir old_folder
rm <file>	Remove a file	rm temp.txt
rm -r <dir>	Remove directory and contents recursively	rm -r build/
rm -rf <dir>	Force remove without prompts	rm -rf node_modules/
rm -i <file>	Prompt before each removal	rm -i *.log
cp <src> <dst>	Copy a file	cp config.yml config.bak
cp -r <src> <dst>	Copy directory recursively	cp -r src/ src_backup/
cp -i <src> <dst>	Prompt before overwrite	cp -i a.txt b.txt
mv <src> <dst>	Move or rename a file/directory	mv old.txt new.txt
touch <file>	Create empty file or update timestamp	touch index.html
ln -s <target> <link>	Create a symbolic link	ln -s /usr/bin/python3 /usr/bin/python
ln <target> <link>	Create a hard link	ln file.txt hardlink.txt
find <path> <expr>	Search for files in a directory tree	find / -name "*.conf"
find <path> -type f	Find only files	find . -type f -name "*.js"
find <path> -type d	Find only directories	find . -type d -name node_modules
find <path> -mtime -N	Find files modified in last N days	find . -mtime -7
find <path> -size +N	Find files larger than N	find / -size +100M
find <path> -exec	Execute command on results	find . -name "*.tmp" -exec rm {} \;
locate <pattern>	Find files by name (uses database)	locate nginx.conf
tree	Display directory structure as a tree	tree -L 2
tree -a	Include hidden files in tree	tree -a -I .git

File Viewing & Editing

Command	Description	Example
cat <file>	Display entire file contents	cat /etc/hosts
cat -n <file>	Display with line numbers	cat -n script.sh
less <file>	View file with scrollable pager	less /var/log/syslog
more <file>	View file page by page (forward only)	more largefile.txt
head <file>	Display first 10 lines	head README.md
head -n N <file>	Display first N lines	head -n 20 data.csv
tail <file>	Display last 10 lines	tail error.log
tail -n N <file>	Display last N lines	tail -n 50 app.log
tail -f <file>	Follow file in real time	tail -f /var/log/syslog
nano <file>	Open file in nano editor	nano ~/.bashrc
vi <file>	Open file in vi editor	vi config.yml
vim <file>	Open file in vim editor	vim server.py
wc <file>	Count lines, words, and bytes	wc essay.txt
wc -l <file>	Count lines only	wc -l *.py
sort <file>	Sort lines alphabetically	sort names.txt
sort -n <file>	Sort numerically	sort -n scores.txt
sort -r <file>	Sort in reverse order	sort -rn scores.txt
sort -u <file>	Sort and remove duplicates	sort -u emails.txt
sort -k N <file>	Sort by Nth field	sort -k 2 data.txt
uniq	Remove adjacent duplicate lines	sort names.txt \| uniq
uniq -c	Count occurrences of each line	sort access.log \| uniq -c
uniq -d	Show only duplicated lines	sort list.txt \| uniq -d
cut -d'X' -fN	Extract fields by delimiter	cut -d',' -f1,3 data.csv
cut -cN-M	Extract characters by position	cut -c1-10 file.txt
paste <f1> <f2>	Merge lines from multiple files	paste names.txt ages.txt
paste -d',' <f1> <f2>	Merge with custom delimiter	paste -d',' col1.txt col2.txt
tr 'a' 'b'	Translate/replace characters	echo "hello" \| tr 'a-z' 'A-Z'
tr -d 'X'	Delete characters	echo "a1b2c3" \| tr -d '0-9'
tr -s ' '	Squeeze repeated characters	echo "a b" \| tr -s ' '

Vi/Vim Quick Reference

Key	Description
i	Enter insert mode
Esc	Return to normal mode
:w	Save file
:q	Quit
:wq or ZZ	Save and quit
:q!	Quit without saving
dd	Delete current line
yy	Yank (copy) current line
p	Paste after cursor
/pattern	Search forward
n / N	Next / previous search result
u	Undo
Ctrl+r	Redo
gg / G	Go to first / last line
:set number	Show line numbers

File Permissions & Ownership

Understanding Permission Notation

Numeric	Symbolic	Permission
0	---	No permission
1	--x	Execute only
2	-w-	Write only
4	r--	Read only
5	r-x	Read + execute
6	rw-	Read + write
7	rwx	Read + write + execute

Permission Commands

Command	Description	Example
chmod 755 <file>	Set rwxr-xr-x (numeric)	chmod 755 deploy.sh
chmod 644 <file>	Set rw-r–r– (numeric)	chmod 644 index.html
chmod u+x <file>	Add execute for owner (symbolic)	chmod u+x script.sh
chmod g-w <file>	Remove write for group	chmod g-w shared.txt
chmod o-rwx <file>	Remove all for others	chmod o-rwx secret.key
chmod a+r <file>	Add read for all	chmod a+r public.txt
chmod -R 755 <dir>	Apply recursively to directory	chmod -R 755 /var/www
chown <user> <file>	Change file owner	chown alice report.txt
chown <user>:<group> <file>	Change owner and group	chown www-data:www-data site/
chown -R <user> <dir>	Change owner recursively	chown -R deploy /opt/app
chgrp <group> <file>	Change group ownership	chgrp developers project/
umask	Display current umask value	umask
umask <value>	Set default permission mask	umask 022

Searching & Filtering

Command	Description	Example
grep <pattern> <file>	Search for pattern in file	grep "error" app.log
grep -i <pattern> <file>	Case-insensitive search	grep -i "warning" log.txt
grep -r <pattern> <dir>	Search recursively in directory	grep -r "TODO" src/
grep -n <pattern> <file>	Show line numbers with matches	grep -n "def " app.py
grep -c <pattern> <file>	Count matching lines	grep -c "404" access.log
grep -l <pattern> <dir>/*	List files containing pattern	grep -rl "API_KEY" config/
grep -v <pattern> <file>	Invert match (exclude pattern)	grep -v "^#" config.ini
grep -E <regex> <file>	Extended regex (same as egrep)	grep -E "err(or\|no)" log.txt
grep -w <word> <file>	Match whole words only	grep -w "main" code.c
grep -A N <pattern>	Show N lines after match	grep -A 3 "Exception" app.log
grep -B N <pattern>	Show N lines before match	grep -B 2 "FATAL" app.log
which <cmd>	Show path of a command binary	which python
whereis <cmd>	Locate binary, source, and man page	whereis gcc
awk '{print $N}'	Print Nth field (space-delimited)	ls -l \| awk '{print $5, $9}'
awk -F'X' '{print $N}'	Print field with custom delimiter	awk -F':' '{print $1}' /etc/passwd
awk '/pattern/'	Filter lines matching pattern	awk '/error/' app.log
awk '{sum+=$1} END {print sum}'	Sum values in a column	awk '{sum+=$1} END {print sum}' nums.txt
sed 's/old/new/' <file>	Replace first occurrence per line	sed 's/http/https/' urls.txt
sed 's/old/new/g' <file>	Replace all occurrences	sed 's/foo/bar/g' data.txt
sed -i 's/old/new/g' <file>	Edit file in place	sed -i 's/v1/v2/g' config.yml
sed 'Nd' <file>	Delete line N	sed '1d' data.csv
sed '/pattern/d' <file>	Delete lines matching pattern	sed '/^$/d' file.txt
xargs <cmd>	Build commands from stdin	find . -name "*.log" \| xargs rm
xargs -I{} <cmd>	Use placeholder for each input	cat urls.txt \| xargs -I{} curl {}
xargs -P N <cmd>	Run N processes in parallel	find . -name "*.png" \| xargs -P 4 optipng

Process Management

Command	Description	Example
ps	Show current shell processes	ps
ps aux	Show all running processes	ps aux
ps aux \| grep <name>	Find a specific process	ps aux \| grep nginx
ps -ef	Full-format listing of all processes	ps -ef --forest
top	Real-time process monitor	top
htop	Interactive process viewer (enhanced)	htop
kill <pid>	Send SIGTERM to a process	kill 1234
kill -9 <pid>	Force kill a process (SIGKILL)	kill -9 1234
kill -HUP <pid>	Send SIGHUP (reload config)	kill -HUP $(cat nginx.pid)
killall <name>	Kill all processes by name	killall firefox
pkill <pattern>	Kill processes matching pattern	pkill -f "python server"
Ctrl+Z	Suspend current foreground process
bg	Resume suspended process in background	bg
bg %N	Resume job N in background	bg %2
fg	Bring background process to foreground	fg
fg %N	Bring job N to foreground	fg %1
jobs	List background/suspended jobs	jobs -l
<cmd> &	Run command in background	./build.sh &
nohup <cmd> &	Run command immune to hangups	nohup python server.py &
nice -n N <cmd>	Start process with priority (N: -20 to 19)	nice -n 10 make -j4
renice N -p <pid>	Change priority of running process	renice 5 -p 1234
wait	Wait for all background jobs to finish	wait
wait <pid>	Wait for specific process	wait 1234

System Information

Command	Description	Example
uname -a	Print all system information	uname -a
uname -r	Print kernel release version	uname -r
hostname	Show or set system hostname	hostname
uptime	Show how long the system has been running	uptime
whoami	Print current username	whoami
id	Print user and group IDs	id
id <user>	Print IDs for a specific user	id www-data
df -h	Disk space usage (human-readable)	df -h
df -i	Show inode usage	df -i
du -sh <path>	Disk usage of a directory (summary)	du -sh /var/log
du -h --max-depth=1	Disk usage one level deep	du -h --max-depth=1 /home
du -ah <path>	Disk usage of all files	du -ah /opt/app
free -h	Memory usage (human-readable)	free -h
free -m	Memory usage in megabytes	free -m
lscpu	Display CPU architecture info	lscpu
lsblk	List block devices (disks, partitions)	lsblk
mount	Show mounted filesystems	mount \| grep ext4
mount <dev> <dir>	Mount a filesystem	mount /dev/sdb1 /mnt/usb
umount <dir>	Unmount a filesystem	umount /mnt/usb
dmesg	Print kernel ring buffer messages	dmesg \| tail -20
lsof	List open files	lsof -i :8080
env	Print environment variables	env \| grep PATH
date	Display current date and time	date "+%Y-%m-%d %H:%M"

Networking

Command	Description	Example
ping <host>	Send ICMP echo requests	ping -c 4 google.com
ping -c N <host>	Send N pings then stop	ping -c 3 192.168.1.1
curl <url>	Transfer data from a URL	curl https://api.example.com
curl -o <file> <url>	Download to a file	curl -o page.html https://example.com
curl -I <url>	Fetch headers only	curl -I https://example.com
curl -X POST -d '<data>'	Send POST request	curl -X POST -d '{"key":"val"}' url
curl -s <url>	Silent mode (no progress)	curl -s https://api.example.com
wget <url>	Download a file	wget https://example.com/file.zip
wget -c <url>	Resume interrupted download	wget -c https://example.com/big.iso
wget -r <url>	Download recursively	wget -r -l 2 https://example.com
ssh <user>@<host>	Remote login via SSH	ssh deploy@10.0.0.5
ssh -p <port> <user>@<host>	SSH on custom port	ssh -p 2222 user@host
ssh -i <key> <user>@<host>	SSH with identity file	ssh -i ~/.ssh/id_rsa user@host
scp <src> <user>@<host>:<dst>	Copy file to remote host	scp app.tar.gz user@server:/tmp/
scp <user>@<host>:<src> <dst>	Copy file from remote host	scp user@server:/var/log/app.log .
scp -r <dir> <user>@<host>:<dst>	Copy directory recursively	scp -r dist/ user@server:/var/www/
rsync -avz <src> <dst>	Sync files efficiently	rsync -avz ./site/ server:/var/www/
rsync --delete <src> <dst>	Sync and delete extraneous files	rsync -avz --delete src/ dst/
rsync --dry-run	Preview changes without applying	rsync -avzn src/ dst/
ss -tlnp	Show listening TCP sockets	ss -tlnp
ss -ulnp	Show listening UDP sockets	ss -ulnp
netstat -tlnp	Show listening ports (legacy)	netstat -tlnp
ip addr	Show IP addresses	ip addr show eth0
ip route	Show routing table	ip route
ifconfig	Show network interfaces (legacy)	ifconfig eth0
dig <domain>	DNS lookup	dig example.com
dig +short <domain>	Short DNS answer	dig +short example.com
nslookup <domain>	Query DNS name servers	nslookup example.com
traceroute <host>	Trace route to host	traceroute google.com
host <domain>	Simple DNS lookup	host example.com

Compression & Archives

Command	Description	Example
tar -cf <archive> <files>	Create tar archive	tar -cf backup.tar /etc/
tar -czf <archive> <files>	Create gzip-compressed tar	tar -czf app.tar.gz src/
tar -cjf <archive> <files>	Create bzip2-compressed tar	tar -cjf data.tar.bz2 data/
tar -cJf <archive> <files>	Create xz-compressed tar	tar -cJf logs.tar.xz /var/log/
tar -xf <archive>	Extract tar archive	tar -xf backup.tar
tar -xzf <archive>	Extract gzip-compressed tar	tar -xzf app.tar.gz
tar -xjf <archive>	Extract bzip2-compressed tar	tar -xjf data.tar.bz2
tar -xJf <archive>	Extract xz-compressed tar	tar -xJf logs.tar.xz
tar -xf <archive> -C <dir>	Extract to specific directory	tar -xzf app.tar.gz -C /opt/
tar -tf <archive>	List archive contents	tar -tzf app.tar.gz
gzip <file>	Compress file (replaces original)	gzip access.log
gunzip <file.gz>	Decompress gzip file	gunzip access.log.gz
gzip -k <file>	Compress and keep original	gzip -k data.csv
zip <archive> <files>	Create zip archive	zip bundle.zip *.txt
zip -r <archive> <dir>	Zip a directory recursively	zip -r project.zip src/
unzip <archive>	Extract zip archive	unzip bundle.zip
unzip -l <archive>	List zip contents	unzip -l project.zip
unzip <archive> -d <dir>	Extract to specific directory	unzip project.zip -d /tmp/
bzip2 <file>	Compress with bzip2	bzip2 database.sql
bunzip2 <file.bz2>	Decompress bzip2	bunzip2 database.sql.bz2
xz <file>	Compress with xz (best ratio)	xz largefile.bin
unxz <file.xz>	Decompress xz	unxz largefile.bin.xz

User Management

Command	Description	Example
useradd <user>	Create a new user	useradd -m alice
useradd -m -s /bin/bash <user>	Create user with home dir and shell	useradd -m -s /bin/bash bob
userdel <user>	Delete a user	userdel alice
userdel -r <user>	Delete user and home directory	userdel -r alice
usermod -aG <group> <user>	Add user to a group	usermod -aG docker alice
usermod -s <shell> <user>	Change user’s login shell	usermod -s /bin/zsh bob
passwd	Change current user’s password	passwd
passwd <user>	Change another user’s password	passwd alice
groups	Show groups for current user	groups
groups <user>	Show groups for a user	groups alice
su <user>	Switch to another user	su alice
su -	Switch to root with root environment	su -
sudo <cmd>	Execute command as superuser	sudo systemctl restart nginx
sudo -u <user> <cmd>	Execute command as another user	sudo -u postgres psql
visudo	Safely edit sudoers file	sudo visudo

Package Management

Debian/Ubuntu (apt)

Command	Description
apt update	Update package index
apt upgrade	Upgrade all installed packages
apt install <pkg>	Install a package
apt remove <pkg>	Remove a package
apt purge <pkg>	Remove package and config files
apt autoremove	Remove unused dependencies
apt search <query>	Search for packages
apt show <pkg>	Show package details
apt list --installed	List installed packages

RHEL/CentOS/Fedora (yum/dnf)

Command	Description
dnf check-update	Check for available updates
dnf upgrade	Upgrade all installed packages
dnf install <pkg>	Install a package
dnf remove <pkg>	Remove a package
dnf search <query>	Search for packages
dnf info <pkg>	Show package info
dnf list installed	List installed packages
yum install <pkg>	Install (older RHEL/CentOS)

macOS (Homebrew)

Command	Description
brew update	Update Homebrew itself
brew upgrade	Upgrade all installed packages
brew install <pkg>	Install a formula
brew uninstall <pkg>	Uninstall a formula
brew search <query>	Search for packages
brew list	List installed packages
brew info <pkg>	Show package info
brew doctor	Check system for issues

I/O Redirection & Pipes

Operator	Description	Example
>	Redirect stdout to file (overwrite)	echo "hello" > file.txt
>>	Redirect stdout to file (append)	echo "world" >> file.txt
<	Redirect file to stdin	sort < unsorted.txt
2>	Redirect stderr to file	cmd 2> errors.log
2>>	Append stderr to file	cmd 2>> errors.log
2>&1	Redirect stderr to stdout	cmd > all.log 2>&1
&>	Redirect both stdout and stderr	cmd &> output.log
\|	Pipe stdout to next command	cat log.txt \| grep "error"
\| tee <file>	Pipe and write to file simultaneously	cmd \| tee output.log
\| tee -a <file>	Pipe and append to file	cmd \| tee -a output.log
<<EOF	Here document (inline input)	cat <<EOF > file.txt
/dev/null	Discard output	cmd > /dev/null 2>&1

Shortcuts & Tips

Keyboard Shortcuts

Shortcut	Description
Ctrl+C	Kill/interrupt current process
Ctrl+Z	Suspend current process
Ctrl+D	Exit current shell / send EOF
Ctrl+R	Reverse search command history
Ctrl+L	Clear the terminal screen
Ctrl+A	Move cursor to start of line
Ctrl+E	Move cursor to end of line
Ctrl+U	Delete from cursor to start of line
Ctrl+K	Delete from cursor to end of line
Ctrl+W	Delete word before cursor
Alt+B	Move back one word
Alt+F	Move forward one word
Tab	Autocomplete command or path
Tab Tab	Show all completions
Up/Down	Navigate command history

History & Aliases

Command	Description	Example
history	Show command history	history
history N	Show last N commands	history 20
!!	Repeat last command	sudo !!
!N	Execute command number N from history	!42
!<string>	Execute last command starting with string	!ssh
!$	Last argument of previous command	mkdir /tmp/test && cd !$
alias <name>='<cmd>'	Create a command alias	alias ll='ls -la'
alias	List all defined aliases	alias
unalias <name>	Remove an alias	unalias ll
type <cmd>	Show how a command is resolved	type ls