Linux and Command Line Guide for Developers

What the shell is, moving around, the directory layout, absolute and relative paths, reading files, and the commands you will use hourly.

Users and groups, reading rwx and octal modes, chmod and chown, sudo, umask, setuid in plain words, and common permission mistakes.

What a process is, ps and top, foreground and background jobs, signals such as SIGTERM and SIGKILL, exit codes, and zombies and orphans.

stdin, stdout and stderr, pipes, redirection, the text tools used to search and reshape data, and real one-line recipes.

Writing safe bash scripts: quoting, set -euo pipefail, arguments, conditions, loops, functions, trap, and ShellCheck.

SSH keys and config, scp and rsync, port forwarding, curl, ss, dig, ping and traceroute, and what each tells you.

The commands you use every day, .gitignore, good commit messages and staging parts of a file with git add -p.

apt and other package managers, running a service with systemd, reading unit files, journalctl, cron and systemd timers.

df, du, free, load average, iostat-style tools, reading logs, and a step-by-step method for a slow or full server.

Images, layers, Dockerfiles and Compose — build once, run the same thing on your laptop and on EC2.

Permissions, processes, pipes, scripting and troubleshooting questions with model answers.