(For a similar solution for Moonlight Embedded, see here)

A script to automatically update the RetroPie Moonlight games list with streamable games for Moonlight Qt from the desired game stream server. This script can be run directly from RetroPie in the Moonlight/Steam games list menu to automatically update/sync the games list with streamable games for Moonlight Qt on a desired chosen game stream server.

What this script does is to pull available games from the desired game stream server from the /home/pi/.config/Moonlight\ Game\ Streaming\ Project/Moonlight.conf file, delete game entries made previously from the script, create a new the list of games in RetroPie and restart Emulationstation to relaod the game list.

The script, specifically the "grep"-part for fetching the games list from Moonlight is loosely inspired by https://github.com/rpf16rj/moonlight_script_retropie and too many other blogs/forum posts to mention.

Pardon any bugs, as I'm still noob in bash scripts.

Feel free to copy, modify and use as you want. The script does what it's supposed to on my home system and won't be very actively supported, updated or maintained.

• Raspberry Pi 4 with Raspbian/Linux (but should work on most Linux devices and distros that can run Moonlight Qt, as well)
• Moonlight Qt
• Latest RetroPie/Emulationstation with Steam or other games menu folders that execute .sh-scripts

• Automatically update the RetroPie Moonlight games list with streamable games for Moonlight Qt on the desired game stream server.
• Can be run directly from the RetroPie Moonlight/Steam games list.
• Restarts EmulationStation to update the games list with new entries.
• Game files already present and not previously created by this script are not overwritten.
• Has a "list" parameter, like in ./_UpdateMoonlightQtGamesList.sh list, to only list the games on the chosen server from the command line.
• Other scripts to quit the running game and streaming session, start Moonlight-Qt GUI and wake the streaming server from RetroPie are included.

1 - Make sure Moonlight Qt is installed, run at least once and paired to the desired game streaming server.

2 - Download and copy the scripts into your RetroPie Moonlight/Steam roms folder, typically "/home/pi/RetroPie/roms/moonlight-qt". Make a new ROMS folder if not already present. Make sure the script files are executable, sudo chmod +x *.sh.
Alternatively, in same folder, run:
git clone https://github.com/Vegz78/UpdateMoonlightQtGamesList && sudo chmod +x ./UpdateMoonlightQtGamesList/_*.sh
Move the script files to the ROMS folder, e.g.: sudo mv *.sh /home/pi/RetroPie/roms/moonlight-qt

3 - Edit _UpdateMoonlightQtGamesList.sh with the desired global variables correct for your setup(server IP/Hostname, roms folder path etc.)

4 - Add the entry from the example below to /etc/emulationstation/es_systems.cfg.

5 - Start RetroPie and navigate to the Moonlight/Steam games list menu.

6 - Run the _UpdateMoonlightQtGamesList entry.

Here are links to more detailed instructions for installing Moonlight Qt on a Raspberry Pi 4 and setting it up in RetroPie(the latter article link will follow shortly, but it is very similar to this).

_UpdateMoonlightQtGamesList.sh of course also works from the command line, and with the argument list, like in _UpdateMoonlightQtGamesList.sh list, you can just list the games on the game streaming server, without updating the RetroPie menu entry files. The list of streamable games on the server is updated every time Moonlight Qt is run.

Edit the file /etc/emulationstation/es_systems.cfg as loosely inspired by TechWizTime.

Add something like this:

  <system>
    <name>Steam</name>
    <fullname>Steam</fullname>
    <path>/home/pi/RetroPie/roms/moonlight-qt</path>
    <extension>.sh .SH</extension>
    <command>%ROM%</command>
    <platform>steam</platform>
    <theme>steam</theme>
  </system>