One-liners

Run the previous command with sudo

$ sudo !!

Spin up a local HTTP server

$ python3 -m http.server 8000

Play ASCII Star Wars

$ telnet towel.blinkenlights.nl

Play a video in terminal

$ mplayer -vo caca video.mp4

Display system information beautifully

$ screenfetch or neofetch

Display fortune and cow

$ fortune | cowsay

Simulate slow typing

$ echo "text" | pv -qL 10

Matrix digital rain

$ cmatrix

Create 100 numbered directories

$ mkdir project{01..100}

Change to the previous directory

$ cd -

Quickly backup a file

$ cp file{,.bak}

Fix typo in the previous command

$ ^wrong^correct^

Get your public IP address

$ curl ifconfig.me

Repeat the last command

$ !!

Edit current command line in your editor

$ Ctrl+X Ctrl+E

Pretty-print JSON from stdin

$ jq .

Find largest files/directories in current directory

$ du -h . | sort -hr | head -20

Show disk usage in human-readable format

$ df -h

Show directory sizes sorted

$ du -sh * | sort -hr

Create a tar.gz backup

$ tar czf backup.tar.gz directory/

Extract a tar.gz archive

$ tar xzf archive.tar.gz

Watch command output refresh every 2 seconds

$ watch command

Kill process by name

$ pkill process_name

View processes sorted by CPU

$ top

List open network ports

$ ss -tuln

Generate random password

$ < /dev/urandom tr -dc A-Za-z0-9 | head -c 32; echo

Search command history interactively

$ Ctrl+R

Count lines in a file

$ wc -l file.txt

Remove duplicate lines

$ sort file | uniq

Find files by name

$ find . -name "*.log"

Find files larger than 100MB

$ find . -type f -size +100M

Copy with progress bar

$ rsync -ah --progress src dest

Download file with resume

$ wget -c url

Mount remote directory over SSH

$ sshfs user@host:/remote /local

Check if command exists

$ command -v cmd >/dev/null && echo yes

List files by modification time

$ ls -lt

Grep recursively ignoring case

$ grep -ir "text" .

Empty/truncate a file

$ > file.txt

Create directory and cd into it

$ mkdir dir && cd dir

Compress with bzip2

$ tar cjf archive.tar.bz2 dir/

Show weather in terminal

$ curl wttr.in

Get full weather report

$ curl v2.wttr.in

Pretty-print XML

$ xmllint --format file.xml

Convert image to different format

$ convert input.jpg output.png

Create animated GIF from images

$ convert -delay 10 -loop 0 *.png animation.gif

Run the train animation

$ sl

Display system info with ASCII art

$ neofetch

Monitor file changes

$ tail -f logfile

Search and replace in files

$ sed -i 's/old/new/g' *.txt

Show only directories

$ ls -d */

Tree view of directory

$ tree

Pipe output to clipboard

$ command | xclip -sel clip

Create symlink

$ ln -s target link

Show current git branch

$ git branch --show-current

Delete files older than 30 days

$ find . -mtime +30 -delete

Find and delete empty directories

$ find . -type d -empty -delete

Show calendar

$ cal

Show colorful calendar

$ cal -3

Generate QR code

$ qrencode -t ANSI "text"

Record terminal session

$ script session.log

Replay terminal session

$ scriptreplay -t timing.log session.log

Check battery percentage

$ upower -i $(upower -e | grep BAT) | grep percentage

Monitor CPU temperature

$ sensors

List cron jobs

$ crontab -l

Encrypt file with gpg

$ gpg -c file

Create RAM disk

$ mount -t tmpfs -o size=1G tmpfs /mnt/ram

Run command in background

$ command &

Run detached from terminal

$ nohup command &

Split large file

$ split -b 1G largefile part-

Reassemble split files

$ cat part-* > largefile

Check file checksum

$ sha256sum file

Download YouTube video

$ yt-dlp url

Play YouTube video in terminal

$ mpv url

Show file with line numbers

$ nl file.txt

Convert DOS to Unix line endings

$ dos2unix file

Reload shell configuration

$ source ~/.bashrc

Check system uptime

$ uptime

Progress bar for any command

$ command | pv -s $(du -b input | cut -f1)

View PDF in terminal

$ pdftotext file.pdf - | less

Burn ISO to USB

$ dd if=iso.iso of=/dev/sdX bs=4M status=progress

Securely wipe drive

$ dd if=/dev/urandom of=/dev/sdX

List hardware info

$ lshw -short

Disk speed test

$ dd if=/dev/zero of=test bs=1G count=1 oflag=dsync

Play beep

$ echo -e "\a"

Show current timezone

$ timedatectl

Fireworks animation

$ for i in {1..50}; do echo -e "\e[${((RANDOM%7+31))}m✨\e[0m"; sleep 0.1; done

Rainbow text

$ echo "text" | lolcat

Display clock in terminal

$ watch -n 1 date

Count files in directory

$ ls | wc -l

Find broken symlinks

$ find . -type l -! -exec test -e {} \; -print

Quick HTTP server in Ruby

$ ruby -run -e httpd . -p 8000

Quick HTTP server in PHP

$ php -S localhost:8000

Quick HTTP server in Node.js

$ npx http-server

Alias to repeat last command

$ alias r='fc -s'

Show most used commands

$ history | awk '{print $2}' | sort | uniq -c | sort -nr | head

Extract any archive

$ a() { case $1 in *.tar.gz) tar xzf $1;; *.zip) unzip $1;; esac; }; a file

Create sparse 10GB file

$ truncate -s 10G file.img

Merge multiple PDFs

$ gs -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=out.pdf in1.pdf in2.pdf

Convert video to GIF

$ ffmpeg -i input.mp4 output.gif

Batch rename files

$ for f in *.txt; do mv "$f" "${f%.txt}.bak"; done

Show git status nicely

$ git status -sb

One-liner web server in bash

$ while true; do echo -e "HTTP/1.1 200 OK\n\n$(date)" | nc -l 8080; done

> TERMINAL_GEAR

> TERMINAL_GEAR