Linux sysadmin tips & shortcuts

Process & Port Management Find what’s using a port: ss -tulnp | grep :8080 Kill process by port: kill -9 $(lsof -t -i:8080) Top processes (better than top): btop Show process tree: ps auxf File & Disk Tricks Human-readable disk usage: df -h du -sh * Find large files: find / -type f -size +500M 2>/dev/null Quickly clean logs: truncate -s 0 /var/log/syslog Search Like a Pro Grep with line numbers + ignore case: grep -in "error" file.log Recursive search: grep -r "password" /etc Use less sm