Linux Command Reference

180+ Linux and bash commands with examples — searchable by name, description, or category. Click Copy to grab any command.

Showing 180 of 180 commands

lsFiles

List directory contents.

Examplels -la

ls -lhFiles

List with human-readable file sizes.

Examplels -lh /var/log

cpFiles

Copy files or directories.

Examplecp file.txt backup.txt

cp -rFiles

Copy a directory recursively.

Examplecp -r src/ dst/

mvFiles

Move or rename files and directories.

Examplemv old.txt new.txt

rmFiles

Remove files.

Examplerm file.txt

rm -rfFiles

Recursively force-remove a directory and its contents.

Examplerm -rf tmp/

touchFiles

Create an empty file or update its timestamp.

Exampletouch notes.txt

catFiles

Print file contents to stdout.

Examplecat /etc/hosts

headFiles

Print the first N lines of a file.

Examplehead -n 20 log.txt

tailFiles

Print the last N lines of a file.

Exampletail -n 50 log.txt

tail -fFiles

Follow a file as it grows (live log watching).

Exampletail -f /var/log/syslog

lessFiles

Page through file contents interactively.

Exampleless /etc/nginx/nginx.conf

moreFiles

Page through file contents (simpler than less).

Examplemore file.txt

fileFiles

Detect the type of a file.

Examplefile image.png

statFiles

Display file or filesystem status.

Examplestat /etc/passwd

ln -sFiles

Create a symbolic link.

Exampleln -s /usr/bin/python3 /usr/local/bin/python

lnFiles

Create a hard link.

Exampleln original.txt hardlink.txt

wc -lFiles

Count lines in a file.

Examplewc -l /etc/passwd

teeFiles

Read stdin and write to both stdout and a file.

Exampleecho "hello" | tee output.txt

pwdDirectories

Print the current working directory.

Examplepwd

cdDirectories

Change the current directory.

Examplecd /var/www/html

cd ~Directories

Change to the home directory.

Examplecd ~

cd -Directories

Switch to the previous directory.

Examplecd -

mkdirDirectories

Create a directory.

Examplemkdir project

mkdir -pDirectories

Create nested directories.

Examplemkdir -p a/b/c

rmdirDirectories

Remove an empty directory.

Examplermdir emptydir

treeDirectories

Display directory structure as a tree.

Exampletree -L 2

du -shDirectories

Show total disk usage of a directory.

Exampledu -sh /home/user

du -sh *Directories

Show disk usage of each item in the current directory.

Exampledu -sh *

grepText

Search for a pattern in files.

Examplegrep "error" /var/log/app.log

grep -iText

Case-insensitive pattern search.

Examplegrep -i "warning" app.log

grep -vText

Invert match — print lines NOT matching the pattern.

Examplegrep -v "^#" config.conf

grep -nText

Print line numbers with matching lines.

Examplegrep -n "TODO" *.ts

grep -rText

Recursively search a directory.

Examplegrep -r "API_KEY" ./src

grep -cText

Count matching lines.

Examplegrep -c "GET" access.log

sedText

Stream editor — substitute text in files.

Examplesed 's/foo/bar/g' file.txt

sed -iText

Edit a file in-place.

Examplesed -i 's/localhost/127.0.0.1/g' config.txt

awkText

Pattern-scanning and text processing language.

Exampleawk '{print $1, $3}' data.txt

awk -FText

Use a custom field separator.

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

cutText

Remove sections from each line of input.

Examplecut -d: -f1 /etc/passwd

sortText

Sort lines of text.

Examplesort names.txt

sort -nText

Sort numerically.

Examplesort -n sizes.txt

sort -rText

Sort in reverse order.

Examplesort -r -n numbers.txt

uniqText

Remove duplicate adjacent lines.

Examplesort file.txt | uniq

uniq -cText

Prefix lines with occurrence count.

Examplesort file.txt | uniq -c | sort -rn

wcText

Count lines, words, and bytes.

Examplewc -lwc document.txt

diffText

Compare two files line by line.

Examplediff file1.txt file2.txt

trText

Translate or delete characters.

Exampleecho 'Hello' | tr '[:lower:]' '[:upper:]'

echoText

Display a line of text.

Exampleecho "Hello, World!"

printfText

Format and print data.

Exampleprintf "Name: %s\nAge: %d\n" Alice 30

xargsText

Build and execute commands from stdin.

Examplecat urls.txt | xargs wget

column -tText

Format input into aligned columns.

Examplecat data.tsv | column -t

ps auxProcess

Show all running processes.

Exampleps aux | grep nginx

topProcess

Real-time process viewer.

Exampletop

htopProcess

Interactive process viewer (requires install).

Examplehtop

killProcess

Send a signal to a process by PID.

Examplekill -9 1234

killallProcess

Kill processes by name.

Examplekillall node

pkillProcess

Kill processes matching a pattern.

Examplepkill -f "python script.py"

pgrepProcess

Find process IDs matching a pattern.

Examplepgrep -u www-data nginx

bgProcess

Resume a stopped job in the background.

Examplebg %1

fgProcess

Bring a background job to the foreground.

Examplefg %1

jobsProcess

List active jobs in the current shell.

Examplejobs -l

nohupProcess

Run a command immune to hangups.

Examplenohup ./server.sh &

niceProcess

Run a command with modified scheduling priority.

Examplenice -n 10 ./backup.sh

reniceProcess

Alter the priority of a running process.

Examplerenice -n 5 -p 1234

lsofProcess

List open files and the processes using them.

Examplelsof -i :3000

straceProcess

Trace system calls made by a process.

Examplestrace -p 1234

pingNetwork

Send ICMP echo requests to a host.

Exampleping -c 4 google.com

curlNetwork

Transfer data to or from a server.

Examplecurl -s https://api.example.com/data

curl -X POSTNetwork

Send an HTTP POST request.

Examplecurl -X POST -H 'Content-Type: application/json' -d '{"key":"val"}' https://api.example.com

wgetNetwork

Download files from the web.

Examplewget https://example.com/file.tar.gz

wget -rNetwork

Recursively download a website.

Examplewget -r -np https://example.com/

sshNetwork

Open a secure shell connection to a remote host.

Examplessh user@192.168.1.10

scpNetwork

Copy files securely between hosts.

Examplescp file.txt user@host:/remote/path/

rsyncNetwork

Efficiently sync files locally or over a network.

Examplersync -avz ./src/ user@host:/dst/

netstat -tulpnNetwork

Show listening TCP/UDP ports and processes.

Examplenetstat -tulpn

ss -tulpnNetwork

Show socket statistics (modern netstat replacement).

Exampless -tulpn

ip addrNetwork

Show all network interfaces and IP addresses.

Exampleip addr show eth0

ip routeNetwork

Display or manipulate the routing table.

Exampleip route show

ifconfigNetwork

Display or configure network interfaces (legacy).

Exampleifconfig eth0

digNetwork

DNS lookup utility.

Exampledig A example.com

nslookupNetwork

Query DNS name servers.

Examplenslookup google.com 8.8.8.8

tracerouteNetwork

Print the route packets take to a network host.

Exampletraceroute google.com

nmapNetwork

Network exploration and port scanner.

Examplenmap -sV 192.168.1.0/24

ncNetwork

Netcat — read/write TCP/UDP connections.

Examplenc -zv host.com 80

chmodPermissions

Change file permissions.

Examplechmod 755 script.sh

chmod +xPermissions

Make a file executable.

Examplechmod +x deploy.sh

chmod -RPermissions

Recursively change permissions.

Examplechmod -R 644 /var/www/html

chownPermissions

Change file owner and group.

Examplechown www-data:www-data /var/www

chown -RPermissions

Recursively change ownership.

Examplechown -R user:group /home/user/app

chgrpPermissions

Change the group ownership of a file.

Examplechgrp developers project/

sudoPermissions

Execute a command as another user (typically root).

Examplesudo apt update

suPermissions

Switch to another user account.

Examplesu - postgres

passwdPermissions

Change a user account password.

Examplepasswd username

umaskPermissions

Set default file creation permissions.

Exampleumask 022

visudoPermissions

Safely edit the sudoers file.

Examplesudo visudo

getfaclPermissions

Display ACL (access control list) for a file.

Examplegetfacl /etc/secret

setfaclPermissions

Set ACL permissions on a file.

Examplesetfacl -m u:alice:rw file.txt

tar -czfArchives

Create a gzipped tar archive.

Exampletar -czf archive.tar.gz ./folder

tar -xzfArchives

Extract a gzipped tar archive.

Exampletar -xzf archive.tar.gz

tar -cjfArchives

Create a bzip2-compressed tar archive.

Exampletar -cjf archive.tar.bz2 ./folder

tar -xjfArchives

Extract a bzip2-compressed tar archive.

Exampletar -xjf archive.tar.bz2

tar -tfArchives

List contents of a tar archive without extracting.

Exampletar -tf archive.tar.gz

zipArchives

Create a zip archive.

Examplezip -r output.zip ./folder

unzipArchives

Extract a zip archive.

Exampleunzip output.zip -d /target

gzipArchives

Compress a file using gzip.

Examplegzip file.txt

gunzipArchives

Decompress a gzip file.

Examplegunzip file.txt.gz

bzip2Archives

Compress a file using bzip2.

Examplebzip2 file.txt

7z aArchives

Create a 7-zip archive.

Example7z a archive.7z ./folder

7z xArchives

Extract a 7-zip archive.

Example7z x archive.7z -o/target

df -hSystem

Show disk space usage in human-readable form.

Exampledf -h

du -shSystem

Show total size of a directory.

Exampledu -sh /var/log

free -hSystem

Display memory usage in human-readable form.

Examplefree -h

uname -aSystem

Print all system information.

Exampleuname -a

hostnameSystem

Show or set the system hostname.

Examplehostname -I

uptimeSystem

Show how long the system has been running.

Exampleuptime

whoamiSystem

Print the current logged-in username.

Examplewhoami

idSystem

Print user and group IDs.

Exampleid username

dateSystem

Display or set the system date and time.

Exampledate "+%Y-%m-%d %H:%M:%S"

calSystem

Display a calendar.

Examplecal 2025

historySystem

Show command history.

Examplehistory | tail -20

envSystem

Print environment variables.

Exampleenv | grep PATH

exportSystem

Set an environment variable for the current session.

Exampleexport NODE_ENV=production

aliasSystem

Create a command shortcut.

Examplealias ll="ls -lah"

systemctl statusSystem

Check the status of a systemd service.

Examplesystemctl status nginx

systemctl restartSystem

Restart a systemd service.

Examplesudo systemctl restart nginx

journalctl -uSystem

View logs for a specific systemd service.

Examplejournalctl -u nginx --since "1 hour ago"

rebootSystem

Reboot the system.

Examplesudo reboot

shutdownSystem

Shut down or restart the system at a scheduled time.

Examplesudo shutdown -h now

findSearch

Find files and directories matching criteria.

Examplefind /var -name "*.log" -mtime +7

find -nameSearch

Find by filename pattern.

Examplefind . -name "*.ts" -type f

find -sizeSearch

Find files by size.

Examplefind / -size +100M -type f

find -execSearch

Execute a command on each found file.

Examplefind . -name "*.tmp" -exec rm {} \;

locateSearch

Find files by name using a prebuilt database.

Examplelocate nginx.conf

whichSearch

Show the full path of a shell command.

Examplewhich python3

whereisSearch

Locate binary, source, and manual page files.

Examplewhereis nginx

typeSearch

Describe how the shell would interpret a command.

Exampletype ls

grep -rnSearch

Recursively search with line numbers.

Examplegrep -rn "TODO" ./src

fdSearch

Fast and user-friendly find alternative.

Examplefd "*.js" ./src

sshSSH

Open a secure shell session to a remote host.

Examplessh user@hostname

ssh -pSSH

Connect to a non-default SSH port.

Examplessh -p 2222 user@hostname

ssh -iSSH

Specify a private key file for authentication.

Examplessh -i ~/.ssh/id_rsa user@host

ssh -LSSH

Create a local port-forwarding tunnel.

Examplessh -L 8080:localhost:80 user@host

ssh -RSSH

Create a remote port-forwarding tunnel.

Examplessh -R 9090:localhost:9090 user@host

ssh-keygenSSH

Generate an SSH key pair.

Examplessh-keygen -t ed25519 -C "you@example.com"

ssh-copy-idSSH

Install your public key on a remote server.

Examplessh-copy-id user@host

scpSSH

Secure file copy between hosts.

Examplescp -r ./dist user@host:/var/www/

sftpSSH

Interactive secure file transfer over SSH.

Examplesftp user@host

ssh-agentSSH

Hold private keys in memory for passwordless auth.

Exampleeval "$(ssh-agent -s)"

ssh-addSSH

Add a private key to the SSH agent.

Examplessh-add ~/.ssh/id_ed25519

apt updatePackage

Update the package list (Debian/Ubuntu).

Examplesudo apt update

apt upgradePackage

Upgrade all installed packages.

Examplesudo apt upgrade -y

apt installPackage

Install a package.

Examplesudo apt install nginx

apt removePackage

Remove a package.

Examplesudo apt remove nginx

apt searchPackage

Search for a package in the repository.

Exampleapt search "text editor"

yum installPackage

Install a package (RHEL/CentOS).

Examplesudo yum install httpd

dnf installPackage

Install a package (Fedora/newer RHEL).

Examplesudo dnf install nodejs

brew installPackage

Install a Homebrew package (macOS/Linux).

Examplebrew install ripgrep

brew updatePackage

Update Homebrew and all formulae.

Examplebrew update && brew upgrade

pip installPackage

Install a Python package.

Examplepip install requests

pip freezePackage

Output installed Python packages.

Examplepip freeze > requirements.txt

npm installPackage

Install Node.js packages.

Examplenpm install express

npm install -gPackage

Install a Node.js package globally.

Examplenpm install -g typescript

snap installPackage

Install a snap package.

Examplesudo snap install code --classic

#!/bin/bashScripting

Shebang line — declares the script interpreter.

Example

#!/bin/bash
echo "Hello"

if [ ... ]Scripting

Conditional statement.

Exampleif [ "$VAR" = "yes" ]; then echo "yes"; fi

for ... inScripting

Iterate over a list.

Examplefor f in *.txt; do echo "$f"; done

while readScripting

Read lines from stdin in a loop.

Examplewhile read line; do echo "$line"; done < file.txt

case ... inScripting

Multi-pattern switch statement.

Examplecase "$1" in start) echo "starting";; stop) echo "stopping";; esac

functionScripting

Define a reusable bash function.

Examplefunction greet() { echo "Hello, $1!"; }

$?Scripting

Exit code of the last executed command.

Examplels /missing; echo $?

$1, $2, ...Scripting

Positional arguments passed to a script.

Exampleecho "First arg: $1"

$@Scripting

All positional arguments as separate words.

Examplefor arg in "$@"; do echo "$arg"; done

&&Scripting

Execute the next command only if the previous succeeded.

Examplemake && make install

||Scripting

Execute the next command only if the previous failed.

Exampleping -c1 host || echo "offline"

set -eScripting

Exit immediately if any command fails.

Example

set -e
npm install
npm run build

set -xScripting

Print each command before executing (debug mode).

Example

set -x
./deploy.sh

trapScripting

Execute a command when the script exits or receives a signal.

Exampletrap "rm -f /tmp/lock" EXIT

readScripting

Read user input from stdin into a variable.

Exampleread -p "Enter name: " name