Linux

1. Linux Fundamentals

• Linux kernel and distributions
• Ubuntu/Debian/Fedora/Arch families
• GNU tools
• Shell vs terminal
• Root and normal users
• Filesystem hierarchy
• Open-source software concepts

Linux command quick reference

Commands vary by distribution and installed packages. Use man command or the distribution documentation before running administrative commands.

pwd
ls -la
cd /path
cd ..
cd ~

mkdir project
touch file.txt
cp file.txt copy.txt
mv copy.txt renamed.txt
rm renamed.txt

cat file.txt
less file.txt
head file.txt
tail -f file.log
grep -R "text" .
find . -type f -name "*.log"

ls -l
chmod 644 file.txt
chmod +x script.sh
sudo chown user:group file.txt
umask

uname -a
hostnamectl
uptime
free -h
df -h
du -sh .
lsblk

ps aux
top
pgrep process
kill PID
pkill process
jobs
fg
bg

ip addr
ip route
ping -c 4 1.1.1.1
ss -tulpn
resolvectl status
curl -I https://example.com
ssh user@host

sudo apt update
sudo apt upgrade
sudo apt install package
sudo apt remove package
apt search package

systemctl status service
sudo systemctl start service
sudo systemctl enable service
journalctl -u service --no-pager

tar -czf backup.tar.gz folder/
tar -xzf backup.tar.gz
zip -r archive.zip folder/
unzip archive.zip