{ description = "A flake of MOTD files."; inputs.nixpkgs.url = github:NixOS/nixpkgs; inputs.flake-utils.url = github:numtide/flake-utils; outputs = { self, nixpkgs, flake-utils }: let motdFiles = { "40k" = ./40k-thought-for-the-day.txt; rebirth = ./boi-rebirth-fortunes.txt; }; in flake-utils.lib.eachDefaultSystem (system: let pkgs = nixpkgs.legacyPackages.${system}; motd = pkgs.stdenv.mkDerivation { pname = "motd"; version = "1.0"; builder = builtins.toFile "motd-builder.sh" '' source $stdenv/setup mkdir -p $out ${builtins.foldl' (a: b: "${a}\n${b}") "" (map (attr: "cp ${motdFiles.${attr}} $out/${attr}.txt") (builtins.attrNames motdFiles))} ''; }; in { defaultPackage = motd; } ); }