Linux Command Cheat Sheet

pwd

Print the current directory

ls

List files and directories

ls -lah

Detailed listing including hidden files and human-readable sizes

ls -lt

List newest files first

ls -lS

List largest files first

cd /path/to/dir

Change directory

cd ..

Move up one directory

cd ~

Go to your home directory

cd -

Return to the previous directory

tree

Display directory contents as a tree

touch file.txt

Create an empty file or update its timestamp

mkdir newdir

Create a directory

mkdir -p a/b/c

Create nested directories

cp file1 file2

Copy a file

cp -r dir1 dir2

Copy a directory recursively

cp -a source/ dest/

Copy while preserving metadata

mv old new

Move or rename a file or directory

rm file.txt

Delete a file

rm -r directory

Delete a directory recursively ⚠

rmdir emptydir

Remove an empty directory

ln -s /target linkname

Create a symbolic link

readlink -f linkname

Resolve a symbolic link

file filename

Identify a file type

stat filename

Show detailed file metadata

find . -type f

Find all files recursively

find /var/log -name '*.log'

Find files by name

find . -type f -size +100M

Find files larger than 100 MB

locate filename

Search the locate database

cat file.txt

Print a file

tac file.txt

Print lines in reverse order

less file.txt

View a file page by page

more file.txt

Simple paged file viewer

head file.txt

Show the first 10 lines

head -n 25 file.txt

Show the first 25 lines

tail file.txt

Show the last 10 lines

tail -f /var/log/syslog

Follow a growing log file

nano file.txt

Edit with Nano

vim file.txt

Edit with Vim

wc -l file.txt

Count lines

wc -w file.txt

Count words

nl file.txt

Show line numbers

column -t file.txt

Align whitespace-separated columns

strings binaryfile

Extract printable strings from a binary

xxd file

Hex dump a file

grep 'text' file.txt

Search for text

grep -i 'text' file.txt

Case-insensitive search

grep -R 'text' /path

Recursive search

grep -n 'text' file.txt

Show matching line numbers

grep -v 'text' file.txt

Show nonmatching lines

grep -E 'cat

dog' file.txt|Extended regex search

cut -d: -f1 /etc/passwd

Extract the first colon-delimited field

sort file.txt

Sort lines alphabetically

sort -n numbers.txt

Sort numerically

uniq file.txt

Remove adjacent duplicates

sort file.txt

uniq -c|Count repeated lines

tr 'a-z' 'A-Z' < file.txt

Convert lowercase to uppercase

sed 's/old/new/g' file.txt

Replace text in output

sed -i 's/old/new/g' file.txt

Replace text in place

awk '{print $1}' file.txt

Print the first field

awk -F: '{print $1}' /etc/passwd

Print the first colon-delimited field

paste file1 file2

Merge files side by side

comm file1 file2

Compare two sorted files

diff -u old.txt new.txt

Show a unified diff

xargs -n1 echo < file.txt

Build command arguments from stdin

ls -l

Show Unix permissions and ownership

chmod 644 file.txt

Set rw-r--r--

chmod 755 script.sh

Set rwxr-xr-x

chmod +x script.sh

Add execute permission

chmod -R 750 directory

Change permissions recursively

chown user file.txt

Change owner

chown user:group file.txt

Change owner and group

chown -R user:group directory

Change ownership recursively

chgrp group file.txt

Change group ownership

umask

Show current creation mask

umask 022

Set a common creation mask

getfacl file.txt

Display ACL permissions

setfacl -m u:alice:rw file.txt

Grant ACL permissions to a user

whoami

Print current username

id

Show UID GID and groups

id username

Show another user's identity information

who

Show logged-in users

w

Show logged-in users and activity

last

Show login history

users

Print logged-in usernames

sudo command

Run a command with elevated privileges

sudo -i

Open a root login shell

su - username

Switch to another user

useradd -m username

Create a user and home directory

adduser username

Interactive user creation on Debian or Ubuntu

passwd username

Set or change a password

usermod -aG sudo username

Add a user to sudo group

usermod -aG group username

Add a user to a supplementary group

groups username

Show group memberships

groupadd groupname

Create a group

userdel -r username

Delete a user and home directory ⚠

getent passwd username

Query account information

ps

Show processes in the current shell

ps aux

Show all processes

ps -ef

Show all processes in full format

top

Interactive process monitor

htop

Enhanced interactive process monitor

pgrep nginx

Find PIDs by name

pidof sshd

Print PID of a program

kill PID

Send SIGTERM

kill -9 PID

Force-kill with SIGKILL

pkill nginx

Kill processes by name

killall processname

Kill all matching processes

nice -n 10 command

Start with adjusted priority

renice 5 -p PID

Change priority of a running process

jobs

List shell jobs

command &

Run a command in the background

fg %1

Bring job 1 to foreground

bg %1

Resume job 1 in background

nohup command &

Keep a command running after logout

watch -n 2 command

Repeat a command every 2 seconds

time command

Measure execution time

uname -a

Show kernel and architecture information

uname -r

Show kernel version

hostname

Show hostname

hostnamectl

Show hostname and system metadata

cat /etc/os-release

Show Linux distribution information

lsb_release -a

Show distribution details if installed

uptime

Show uptime and load averages

date

Show current date and time

timedatectl

Show time configuration

cal

Display a calendar

arch

Show machine architecture

lscpu

Show CPU information

free -h

Show memory usage

vmstat

Show memory CPU and process statistics

lsmem

Show memory block information

dmidecode

Show SMBIOS hardware information

lspci

List PCI devices

lsusb

List USB devices

sensors

Show hardware temperatures if configured

df -h

Show filesystem disk usage

df -i

Show inode usage

du -sh directory

Show total size of a directory

du -h --max-depth=1

Show one-level directory sizes

lsblk

List block devices

lsblk -f

Show filesystems on block devices

blkid

Show UUIDs and filesystem types

fdisk -l

List partition tables

parted -l

List partitions with GNU Parted

mount

Show mounted filesystems

mount /dev/sdb1 /mnt

Mount a filesystem

umount /mnt

Unmount a filesystem

findmnt

Show mounted filesystems as a tree

fsck /dev/sdXN

Check or repair an unmounted filesystem ⚠

mkfs.ext4 /dev/sdXN

Create an ext4 filesystem and erase existing filesystem data ⚠

mkswap /dev/sdXN

Create swap space ⚠

swapon --show

Show active swap

swapon /swapfile

Enable swap

swapoff /swapfile

Disable swap

sync

Flush filesystem buffers

ip addr

Show interfaces and IP addresses

ip -br addr

Brief interface and address view

ip link

Show link state

ip route

Show routing table

ip neigh

Show neighbor or ARP table

hostname -I

Show host IP addresses

ping 8.8.8.8

Test IP connectivity

ping -c 4 example.com

Send four ICMP requests

traceroute example.com

Trace the network path

tracepath example.com

Trace path without raw-socket privileges

ss -tulpn

Show listening TCP and UDP sockets

ss -tan

Show TCP connections

netstat -tulpn

Legacy socket and listener view

curl https://example.com

Fetch a URL

curl -I https://example.com

Fetch HTTP headers

curl -O https://example.com/file.iso

Download using the remote filename

wget https://example.com/file.iso

Download a file

dig example.com

Query DNS

dig +short example.com

Concise DNS query

nslookup example.com

Simple DNS lookup

host example.com

DNS lookup with host

resolvectl status

Show systemd-resolved status

nmcli device status

Show NetworkManager devices

nmcli connection show

List NetworkManager connections

ethtool eth0

Show Ethernet link details

ssh user@server

Connect to a remote host

ssh -p 2222 user@server

SSH on a custom port

ssh-keygen -t ed25519

Generate an Ed25519 SSH key

ssh-copy-id user@server

Install your public key remotely

scp file user@server:/path/

Copy a file to a remote host

scp user@server:/path/file .

Copy a remote file locally

scp -r directory user@server:/path/

Copy a directory over SSH

sftp user@server

Open an SFTP session

rsync -av source/ dest/

Synchronize directories locally

rsync -avz source/ user@server:/path/

Synchronize to a remote host

ssh -L 8080:localhost:80 user@server

Create a local SSH port forward

systemctl status ssh

Show service status

systemctl start ssh

Start a service

systemctl stop ssh

Stop a service

systemctl restart ssh

Restart a service

systemctl reload nginx

Reload service configuration if supported

systemctl enable ssh

Enable a service at boot

systemctl disable ssh

Disable a service at boot

systemctl enable --now ssh

Enable and start immediately

systemctl list-units --type=service

List loaded services

systemctl list-unit-files

List installed unit files

systemctl daemon-reload

Reload systemd unit definitions

systemctl is-active ssh

Check whether a service is active

systemctl is-enabled ssh

Check whether a service starts at boot

systemctl reboot

Reboot the system

systemctl poweroff

Power off the system

journalctl

View the systemd journal

journalctl -b

Show logs from current boot

journalctl -b -1

Show logs from previous boot

journalctl -u ssh

Show logs for a service

journalctl -u nginx -f

Follow service logs

journalctl -p err

Show error-priority messages

journalctl --since '1 hour ago'

Show recent logs

dmesg

Show kernel messages

dmesg -T

Show kernel messages with readable timestamps

tail -f /var/log/syslog

Follow Ubuntu or Debian system log

tail -f /var/log/messages

Follow common RHEL-family system log

lastb

Show failed login attempts where supported

sudo apt update

Refresh package indexes

sudo apt upgrade

Upgrade installed packages

sudo apt full-upgrade

Upgrade allowing dependency changes

sudo apt install package

Install a package

sudo apt remove package

Remove a package

sudo apt purge package

Remove package and configuration

sudo apt autoremove

Remove unused dependencies

apt search keyword

Search packages

apt show package

Show package information

dpkg -l

List installed Debian packages

dpkg -L package

List files installed by a package

sudo dpkg -i file.deb

Install a local DEB package

sudo dnf check-update

Check for updates

sudo dnf upgrade

Upgrade installed packages

sudo dnf install package

Install a package

sudo dnf remove package

Remove a package

dnf search keyword

Search packages

dnf info package

Show package information

rpm -qa

List installed RPM packages

rpm -ql package

List files from an installed RPM package

sudo pacman -Syu

Update repositories and upgrade the system

sudo pacman -S package

Install a package

sudo pacman -R package

Remove a package

sudo pacman -Rs package

Remove a package and unneeded dependencies

pacman -Ss keyword

Search repositories

pacman -Qi package

Show installed package information

tar -czf archive.tar.gz directory/

Create a gzip-compressed tar archive

tar -xzf archive.tar.gz

Extract a tar.gz archive

tar -cJf archive.tar.xz directory/

Create an xz-compressed tar archive

tar -xJf archive.tar.xz

Extract a tar.xz archive

tar -tf archive.tar.gz

List archive contents

zip -r archive.zip directory/

Create a ZIP archive

unzip archive.zip

Extract a ZIP archive

gzip file

Compress to file.gz

gunzip file.gz

Decompress gzip

xz file

Compress with xz

unxz file.xz

Decompress xz

7z a archive.7z directory/

Create a 7-Zip archive

7z x archive.7z

Extract a 7-Zip archive

echo $PATH

Print executable search path

env

Show environment variables

printenv

Print environment variables

export VAR=value

Set an environment variable

unset VAR

Remove an environment variable

history

Show shell history

history

grep ssh|Search shell history

!!

Run the previous command again

!123

Run history entry 123

alias ll='ls -lah'

Create a temporary alias

unalias ll

Remove an alias

which python3

Locate an executable

command -v python3

Portable command lookup

type cd

Describe how a command name is interpreted

source ~/.bashrc

Reload Bash configuration

bash script.sh

Run a Bash script

./script.sh

Run an executable script from current directory

command > file.txt

Redirect stdout and overwrite

command >> file.txt

Append stdout

command 2> errors.txt

Redirect stderr

command > out.txt 2>&1

Redirect stdout and stderr together

command1

command2|Pipe output into another command

command

tee file.txt|Display and save output

command

tee -a file.txt|Display and append output

command < input.txt

Use a file as stdin

cmd1 && cmd2

Run cmd2 only if cmd1 succeeds

cmd1

| cmd2|Run cmd2 only if cmd1 fails

cmd1 ; cmd2

Run sequentially regardless of status

dd if=input.img of=output.img bs=4M status=progress

Copy an image or file with progress

dd if=/dev/sdX of=disk.img bs=4M status=progress

Create a raw disk image ⚠

dd if=disk.img of=/dev/sdX bs=4M status=progress

Write a raw image to a disk ⚠

crontab -e

Edit current user's cron jobs

crontab -l

List current user's cron jobs

sudo crontab -e

Edit root's cron jobs

at 17:00

Schedule a one-time job for 5 PM

atq

List queued at jobs

atrm JOBID

Remove a queued at job

systemctl list-timers

List systemd timers

sudo ufw status

Show UFW status

sudo ufw enable

Enable UFW

sudo ufw allow 22/tcp

Allow TCP port 22

sudo ufw deny 23/tcp

Deny TCP port 23

sudo ufw delete allow 22/tcp

Delete an allow rule

sudo firewall-cmd --state

Check firewalld status

sudo firewall-cmd --list-all

Show active firewalld rules

sudo firewall-cmd --add-service=http --permanent

Permanently allow HTTP

sudo firewall-cmd --reload

Reload firewalld

sudo nft list ruleset

Display nftables rules

docker version

Show Docker versions

docker info

Show Docker engine information

docker ps

List running containers

docker ps -a

List all containers

docker images

List local images

docker pull nginx

Download an image

docker run --name web -p 8080:80 -d nginx

Run nginx in the background

docker stop web

Stop a container

docker start web

Start a stopped container

docker restart web

Restart a container

docker rm web

Remove a stopped container

docker rmi nginx

Remove an image

docker logs web

Show container logs

docker logs -f web

Follow container logs

docker exec -it web bash

Open a Bash shell inside a container

docker inspect web

Show detailed metadata

docker stats

Show live resource usage

docker volume ls

List volumes

docker network ls

List networks

docker compose up -d

Start a Compose project

docker compose down

Stop and remove Compose resources

docker compose logs -f

Follow Compose logs

git init

Initialize a repository

git clone URL

Clone a remote repository

git status

Show repository status

git add file

Stage a file

git add .

Stage changes under the current directory

git commit -m 'message'

Create a commit

git log --oneline --graph --decorate

Show a compact commit graph

git diff

Show unstaged changes

git diff --staged

Show staged changes

git branch

List branches

git switch branch

Switch branches

git switch -c newbranch

Create and switch branches

git merge branch

Merge a branch

git pull

Fetch and integrate remote changes

git push

Push commits

git remote -v

Show remotes

lspci -nn

List PCI devices with numeric IDs

lsusb -v

Show verbose USB information

lsmod

List loaded kernel modules

modinfo module

Show module information

sudo modprobe module

Load a kernel module

sudo modprobe -r module

Unload a kernel module

udevadm info /dev/sda

Query udev device information

smartctl -a /dev/sda

Show SMART disk health

nvme list

List NVMe devices

nvme smart-log /dev/nvme0

Show NVMe health information

top

Live process and resource view

htop

Enhanced process monitor

free -h

Memory and swap usage

vmstat 1

Sample memory and CPU every second

iostat -xz 1

Detailed disk I/O statistics

iotop

Show processes performing disk I/O

mpstat -P ALL 1

Show per-CPU usage

sar -u 1 5

Collect CPU statistics

pidstat 1

Show per-process resource usage

du -ah .

sort -h | tail -20|Show the 20 largest items below current directory

find . -type f

wc -l|Count files recursively

find . -type f -empty

Find empty files

find . -type d -empty

Find empty directories

ps aux --sort=-%mem

head|Show top memory-consuming processes

ps aux --sort=-%cpu

head|Show top CPU-consuming processes

ss -tulpn

grep LISTEN|Show listening sockets

journalctl -p err -b

Show errors from current boot

ip -br a

Quick network summary

df -hT

Show disk usage and filesystem types

grep -Rni 'searchterm' .

Recursive case-insensitive search with line numbers

find . -type f -mtime -1

Find files modified in the last 24 hours

find . -type f -mtime +30

Find files older than 30 days

tar -czf backup-$(date +%F).tar.gz /path/to/data

Create a dated compressed backup

man command

Open a manual page

command --help

Show command help

info command

Open GNU Info documentation

apropos keyword

Search manual-page descriptions

whatis command

Show a one-line command description

tldr command

Show example-focused documentation if installed