Running Proton without Steam

#!/bin/bash

# This script creates and launches a Windows executable
# in a Proton environment.
#
# My variables are all lowercase (violating common practice)
# to prevent conflicts and to make it clear what is needed and
# what is optional.

workdir=$(pwd)


##############
## Settings ##
##############

## Game Executable ##
#game_exe="$workdir/game.exe"

## Proton Runner ##
protonexec="/home/$USER/.steam/steam/steamapps/common/Proton - Experimental/proton"

## Proton Data Path ##
protondata="$workdir/proton_data/"


##########################
## Setup and run Proton ##
##########################

## Define variables ##
export STEAM_COMPAT_CLIENT_INSTALL_PATH="$protondata"
export STEAM_COMPAT_DATA_PATH="$STEAM_COMPAT_CLIENT_INSTALL_PATH"
export WINEPREFIX="$STEAM_COMPAT_DATA_PATH/pfx" # Only used for winetricks

## Create directory structure ##
mkdir -p "$STEAM_COMPAT_DATA_PATH/pfx"

## Launch Proton ##
"$protonexec" run "$game_exe"

## Alternatively launch winetricks ##
# will not use proton.
# Don't forget to comment out the launch proton argument above.
#$WINEPREFIX winetricks