Essential Linux Commands for Web Developers

You've built your app, but now you need to debug it on the production server. There is no VS Code here. Just a blinking cursor.

Here are the commands you actually need.

1. File Navigation & Manipulation

• ls -lah: List all files, including hidden ones (.env), showing sizes in human-readable format (h).
• cd -: Go back to the previous directory. (Super useful).
• tail -f error.log: Watch the end of a file in real-time. Crucial for monitoring logs while hitting an API.

2. Process Management

Help! The server is slow.

• htop: Interactive process viewer. Who is eating the CPU?
• kill -9 <PID>: Force kill a process ID. The nuclear option.
• ps aux | grep node: Find all running Node.js processes.

3. Network Debugging

• curl -I https://google.com: Fetch headers only. Check if leading 301 Redirect or 500 Error.
• netstat -tulpn (or ss -tulpn): "What port is currently in use?" Used when you get EADDRINUSE: 3000.

4. Permissions

• chmod +x script.sh: Make a file executable.
• chown -R user:group directory: Recursively change ownership.

Pro Tip: Chaining Commands

The pipe | is your friend. cat access.log | grep "404" | wc -l Read log -> Find 404s -> Count the lines.

Quiz

Conclusion

You don't need to be a SysAdmin. But knowing how to read a log file (tail) and find a zombie process (top/htop) distinguishes a Junior from a Senior.