Intro

Updated

September 4, 2026

Intro

This part covers how to find answers on the system itself before searching the web. Offline docs match the versions you actually installed — critical when flags change between releases.

Commands in this part

Command Role
man man displays the system manual.
help (shell builtin) help shows documentation for shell builtins — commands implemented inside the shell itself (cd, export, read, [[,…
info info reads documentation in Info (Texinfo) format.
apropos apropos searches man page names and short descriptions for keywords.
whatis whatis prints single-line descriptions from the man-db whatis index.

Suggested starting points

  1. Quick hint: whatis cmd or cmd --help.
  2. Full story: man cmd (try section 5 for configs, 8 for admin tools).
  3. Forgot the name: apropos keyword, then open the best hit with man.
  4. Shell builtin: type cmd, then help cmd if it is a builtin.
  5. GNU deep dive: info for coreutils, bash, and related tools.