Man pages

Man pages are a form of documentation available on Unix-like systems.

See the Archwiki and Wikipedia entries for more information.

NixOS: Display configuration options

The NixOS option system creates a manpage with all options and their documentation.

man 5 configuration.nix

This is a lightweight alternative to the “Configuration Options” page in nixos-help. There is also NixOS options website

NixOS: Some man pages are missing

Development man pages

The “Linux man-pages project” provides a set of documentation of the Linux programming API, mostly section `3`. You can access them by adding them to your system packages:

environment.systemPackages = [ pkgs.man-pages pkgs.man-pages-posix ];

To try it out: man 3 scanf.

Libraries and development utilities might provide additional documentation and manpages. You can add those to your system like this:

documentation.dev.enable = true;

See also: the other options in the `documentation` namespace.