Linux Commands Quick Reference

pwd

ls -la

cd projects

cd ..

cd ~

cd -

mkdir docs

mkdir -p a/b/c

touch notes.txt

cp a.txt b.txt

cp -r src/ backup/

mv old.txt new.txt

rm file.txt

rm -r folder/

rmdir empty-folder

ln -s /path/to/target link-name

find . -name "*.log"

find . -type f -size +100M

df -h

du -sh *

cat file.txt

less file.txt

head -n 20 file.txt

tail -n 20 file.txt

tail -f /var/log/syslog

grep "error" app.log

grep -rin "todo" src/

wc -l file.txt

sort names.txt | uniq

sort | uniq -c | sort -nr

cut -d, -f1,3 data.csv

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

diff a.txt b.txt

ls > files.txt

echo hi >> log.txt  # append

cmd 2> errors.txt

cmd > all.txt 2>&1

ps aux | grep node

npm test && npm run build

long-task &

nohup long-task &

echo "Today is $(date +%F)"

find . -name "*.tmp" -print0 | xargs -0 rm

chmod +x deploy.sh

chmod 644 file.txt   # rw-r--r--

chmod 755 dir/      # rwxr-xr-x

sudo chown -R www-data:www-data /var/www

sudo apt update

whoami

id

su - username

ps aux

top

htop

pgrep -a node

ps aux | grep node

kill 1234

kill -9 1234

pkill node

sudo lsof -i :3000

ss -ltnp

free -h

uptime

sudo systemctl status nginx

sudo systemctl restart nginx

journalctl -u nginx -f

echo $PATH

export API_KEY=abc123

history

Ctrl+R   # search history

curl https://example.com

curl -I https://example.com  # headers

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

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

ping -c 4 example.com

ip addr

dig example.com

ssh user@host

ssh -i ~/.ssh/key.pem user@host

scp file.txt user@host:/tmp/

rsync -avz src/ user@host:/srv/app/

tar -czvf archive.tar.gz folder/

tar -xzvf archive.tar.gz

zip -r archive.zip folder/

unzip archive.zip

sudo apt update

sudo apt install git

sudo dnf install git

sudo pacman -S git

man tar

tar --help