aoe2de protocol handler for Linux

bgstack15

2023-11-19 08:56

Overview

The url using a custom protocol aoe2de://1/12394872348 can be used by Age of Empires 2: Definitive Edition to directly join or spectate a game. This behavior can be established in GNU/Linux with some easy customization.

Making the protocol links work

Modify xdg-open.

By default, xdg-open does not recognize protocol aoe2de:// as a URL because of the digit. It treats the protocol as a file instead of a url, so I had to modify /usr/bin/xdg-open:

sudo sed -i.bup -r -e '/grep -q.\*:alpha:.\*then/s/:alpha:/:alnum:/g;' /usr/bin/xdg-open

Alternatively, you just need to modify the regular expression inside function to use alnum:

# Returns true if argument is a file:// URL or path
is_file_url_or_path()
{
    if echo "$1" | grep -q '^file://' \
            || ! echo "$1" | egrep -q '^[[:alnum:]+\.\-]+:'; then
        return 0
    else
        return 1
    fi
}

Establish script to run AOEURLHelper.exe.

I named it ~/bin/aoe2de-protocol.

	`#!/bin/sh`
	`# Startdate: 2023-11-14-3 19:51`
	`# Author: bgstack15`
	`# Documentation:`
	`# Because I use Proton Experimental, I use that path.`
	`# 813780 = steamid for Age of Empires 2 Definitive Edition`
	`STEAM_COMPAT_CLIENT_INSTALL_PATH=~/.steampath STEAM_COMPAT_DATA_PATH="${HOME}/.local/share/Steam/steamapps/compatdata/813780" ${HOME}/.local/share/Steam/steamapps/common/Proton\ -\ Experimental/proton runinprefix "${HOME}/.local/share/Steam/steamapps/compatdata/813780/pfx/drive_c/Program Files (x86)/AOE URL Helper/AOEURLHelper.exe" "${@}"`

Establish desktop file with mimetype handler.

I named mine ~/.local/share/applications/aoe2de-protocol.desktop.

[Desktop Entry]
Name=AOEURLHelper
Comment=Load url for Age of Empires 2: Definitive Edition
Exec=aoe2de-protocol %u
Icon=steam_icon_813780
Terminal=false
Type=Application
Categories=Game;
MimeType=x-scheme-handler/aoe2de;

Ensure this desktop file is used with xdg-open.

Run these commands.

$ xdg-mime default aoe2de-protocol.desktop x-scheme-handler/aoe2de
$ xdg-mime query default x-scheme-handler/aoe2de
aoe2de-protocol.desktop

Configure Firefox-based web browser to use this application for links of this protocol.

In about:config, set a new boolean network.protocol-handler.expose.aoe2de = false. Then visit one of the lobby browsers (below) and find a join link. Select the link, and choose your new .desktop file.

The first time, it failed. When I tried again, the web browser showed the second menu item named "AOEURLHelper" which is what I put in that "Name" field and it did invoke my shell script and then try to join the game.

Additional thoughts

The xdg-open aoe2de://0/123412341234 invocation works when the game is not already running, and when the game is already running. Of course, due to how long it takes the game to load, loading a aoe2de link loads faster if the game is already running.

Protocol description

This is not a specification because I don't know of any that has been published.

aoe2de://0/126811196

This link tries to join game id 126811196. You can learn your game id when you are the host, from the button in the upper-right of the lobby screen.

aoe2de://1/123498272

The top virtual directory /1/ indicates that the program should try to spectate the match.

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