25 Linux Commands Every DevOps Engineer Should Know

Almost every cloud server runs Linux, so command-line fluency is the fastest way to become useful on a DevOps team.

Files and navigation

• ls, cd, pwd, find: move around and locate files.
• cat, less, head, tail -f: read files and follow logs live.
• cp, mv, rm, mkdir: manage files (check before you rm).
• chmod, chown: fix permissions and ownership.

Searching and text

• grep: search text and logs.
• awk, sed: transform output.
• sort, uniq, wc: count and summarise.

Processes and resources

• ps, top, htop: see what is running.
• kill: stop a process.
• df -h, du -sh, free -m: disk and memory.
• systemctl, journalctl: manage services and read their logs.

Networking

• curl, wget: test HTTP endpoints.
• ping, traceroute, dig: check reachability and DNS.
• ss -tulpn: see listening ports.
• ssh, scp, rsync: connect and transfer.

Practise by launching a small EC2 instance, installing a web server, breaking it on purpose, and fixing it using only these commands.