Man pages are an overlooked resource for quality documentation.

These are some of my favorites.

man

man man.

If you've read man pages before, you may have noticed that many have a number associated with them. Have you ever learnt what those numbers mean?

For example, man open shows the man pages for OPEN(1). What does this 1 mean?

As explained by man man, this number is called the "section number" of a page. It classifies what type of software is documented in the page. As an example, 1 is used to categorize executables or shell commands. See man man for explanations of other section numbers.

For man pages that have multiple sections that share the same page name, you can use the section number to distinguish what you're looking for.

As an example, man 1 read will show the man page for the read shell command. man 2 read will show the man page for the read sys-call (since 2 is the section number used for system calls).

git, giteveryday, gittutorial, gitcli

These pages are a good starting point for discovering new Git knowledge, aimed at both advanced and casual users.

man git
man giteveryday
man gittutorial
man gitcli

signal-safety

This man-page was my first contact with reentrant functions. Prior to reading this I hadn't heard of the term.

man signal-safety