name: findFile args: ['search path', 'lookup path']

Look up the given path with the given search path.

A search path is represented list of attribute sets with two attributes, prefix, and path. prefix is a relative path. path denotes a file system location; the exact syntax depends on the command line interface.

Examples of search path attribute sets:

• {
    prefix = "nixos-config";
    path = "/etc/nixos/configuration.nix";
  }
  

• {
    prefix = "";
    path = "/nix/var/nix/profiles/per-user/root/channels";
  }
  

The lookup algorithm checks each entry until a match is found, returning a path value of the match.

This is the process for each entry: If the lookup path matches prefix, then the remainder of the lookup path (the "suffix") is searched for within the directory denoted by patch. Note that the path may need to be downloaded at this point to look inside. If the suffix is found inside that directory, then the entry is a match; the combined absolute path of the directory (now downloaded if need be) and the suffix is returned.

The syntax

<nixpkgs>

is equivalent to:

builtins.findFile builtins.nixPath "nixpkgs"