redux: add update script

pkgs/applications/audio/redux/default.nix

@@ -1,6 +1,7 @@
 { lib
 , stdenv
 , fetchurl
+, writeScript
 , libX11
 , libXext
 , alsa-lib
@@ -48,6 +49,23 @@ stdenv.mkDerivation rec {
     runHook postInstall
   '';
 
+
+  passthru.updateScript = writeScript "update-redux" ''
+    #!/usr/bin/env nix-shell
+    #!nix-shell -I nixpkgs=./. -i bash -p curl htmlq common-updater-scripts
+    set -euo pipefail
+
+    new_version="$(
+      curl 'https://files.renoise.com/demo/' \
+        | htmlq a --text \
+        | grep -E '^Renoise_Redux_([0-9]+_?)+_Demo_Linux_x86_64\.tar\.gz$' \
+        | grep -Eo '[0-9]+(_[0-9]+)*' \
+        | head -n1 \
+        | tr _ .
+    )"
+    update-source-version redux "$new_version" --system="x86_64-linux"
+  '';
+
   meta = with lib; {
     description = "Sample-based instrument, with a powerful phrase sequencer";
     homepage = "https://www.renoise.com/products/redux";