Man pages are a form of documentation available on Unix-like systems.
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: 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.manpages ];
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.