# Show current directory
pwd

# List files
ls -la

# Check disk usage
df -h

# Check memory usage
free -h

# Check running processes
ps aux

# Check system uptime
uptime

# Check IP address
ip addr

# Update packages
sudo apt update

# Upgrade packages
sudo apt upgrade

# Restart a service
sudo systemctl restart SERVICE_NAME

# Check service status
sudo systemctl status SERVICE_NAME

# View recent system logs
journalctl -xe

# Find a file
find / -name "filename" 2>/dev/null

# Check listening ports
sudo ss -tulpn