Linux Tutorial

1. Linux Introduction

What Linux is, why backend engineers rely on it, and the major distribution families.

2. File System and Permissions

The Linux filesystem hierarchy, reading and changing permissions, and symbolic vs hard links.

3. Essential Commands

Navigation, file operations, text processing, piping, redirection, and process management.

4. Shell Scripting Basics

Writing a real Bash script with variables, conditionals, loops, and command substitution.

5. Networking Basics

Inspecting interfaces and routes with ip, checking listening ports with ss, and basic firewalling with ufw/iptables.

6. systemd and Services

Writing a unit file, controlling it with systemctl, and reading logs with journalctl.

7. Performance Monitoring Tools

Finding what is using CPU, memory, and disk with top/htop, df/du, and iostat.

8. Security Hardening

SSH key authentication, disabling root login and passwords, and basic brute-force protection with fail2ban.

9. Linux Interview Questions

Common Linux interview questions covering permissions, processes, and the command line.