add programs.nix-script module

modules/programs/nix-script.nix

@@ -0,0 +1,47 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.programs.nix-script;
+
+  nix-script = pkgs.substituteAll {
+    inherit (cfg) name;
+    src = ../../pkgs/nix-tools/nix-script.sh;
+    dir = "bin";
+    isExecutable = true;
+  };
+
+in
+
+{
+  options = {
+
+    programs.nix-script.enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to enable the nix script.
+      '';
+    };
+
+    programs.nix-script.name = mkOption {
+      type = types.str;
+      default = "nix";
+      description = ''
+        Name to use for the nix script.
+      '';
+    };
+
+  };
+
+  config = mkIf cfg.enable {
+
+    environment.systemPackages =
+      [ # Nix wrapper script
+        nix-script
+      ];
+
+  };
+}