DualScope: Run two steam instances with gamescope with different user accounts (split screen on any game!)

dualscope.sh

#!/bin/bash

# a little script i made to open two gamescope sessions of steam
# i SUCK at making bash script, so expect a lot of bugs or issues :<
# made for arch linux in mind
# you need another account on your device to use this

# if u use pipewire and your audio is not working, take a look at this:
# https://wiki.archlinux.org/title/PipeWire#Multi-user_audio_sharing

# The gamescope params for both of the processes
GAMESCOPE_PARAMS="-e -b -w 960 -h 360 -W 1440 -H 540"
# Params for both steams
STEAM_PARAMS="-gamepadui"

# The secondary account you will use
RUNAS_ACC="YOUR SECONDARY ACCOUNT"

GAMESCOPE_BIN="/usr/bin/gamescope"
RUNAS_BIN="/usr/bin/run-as"
STEAM_BIN="/usr/bin/steam"

CHANGED_DEVICES=()
GAMESCOPE_PRIMARY_PID=""
GAMESCOPE_SECONDARYPID=""

# hiding kde panels using this:
# https://github.com/luisbocanegra/plasma-panel-colorizer
toggle_panels() {
  local state="$1"
  local value="false"
  if [ "$state" = "true" ]; then
    value="true"
  fi

  local status="string:stockPanelSettings.visible {\"enabled\": true, \"value\": $value}"
  dbus-send --session --type=signal /preset "luisbocanegra.panel.colorizer.all.property" "$status"
}

startup() {
  echo "Hiding the KDE panels!"
  toggle_panels "false"
}

cleanup() {
  echo "Showing the KDE panels again"
  toggle_panels "true"
  echo "Returning ownership to every device"
  return_devices_ownership

  if [[ -n "$GAMESCOPE_PRIMARY_PID" ]]; then
    echo "Killing primary gamescope..."
    kill -TERM "$GAMESCOPE_PRIMARY_PID" 2>/dev/null || true
  fi

  if [[ -n "$GAMESCOPE_SECONDARY_PID" ]]; then
    echo "Killing secondary gamescope..."
    kill -TERM "$GAMESCOPE_SECONDARY_PID" 2>/dev/null || true
  fi
}

show_devices_list() {
  local devices=""
  local name=""
  while IFS= read -r line; do
    if [[ $line == N:\ Name=* ]]; then
      name=$(echo "$line" | sed 's/N: Name=//' | tr -d '"')
    fi
    if [[ $line == *Handlers=* ]]; then
      local event_dev=$(echo "$line" | grep -o 'event[0-9]*' | sed 's/event//')

      if [[ -n $name && -n $event_dev ]]; then
        # aditional info 4 controllers
        local device_info=""
        if [[ $name == *"Xbox"* || $name == *"Controller"* || $name == *"Gamepad"* || $name == *"Joystick"* ]]; then
          device_info=" 󰊗"
        elif [[ $name == *"Keyboard"* || $name == *"keyboard"* ]]; then
          device_info=" ⌨️"
        elif [[ $name == *"Mouse"* || $name == *"mouse"* ]]; then
          device_info=" 󰍽"
        fi

        devices+="$event_dev - $name$device_info"$'\n'
        name=""
      fi
    fi
  done < /proc/bus/input/devices

  echo -e "$devices"
}

change_device_ownership() {
  local profile="$1"
  local device="$2"
  local device_path="/dev/input/event$device"

  sudo chown "$profile" "$device_path"
  sudo chmod 600 "$device_path"
}

get_devices_to_change() {
  local profile="$1"
  echo "Select the devices to transfer for the $profile profile:"
  show_devices_list

  echo "Please, input your device list divided by a comma (1,2,3,4,etc):"
  read input_string

  IFS=',' read -r -a NEW_DEVICES <<< "$input_string"
  CHANGED_DEVICES+=("${NEW_DEVICES[@]}")

  for device in "${NEW_DEVICES[@]}"; do
    change_device_ownership "$profile" "$device"
  done
}

return_devices_ownership() {
  for device in "${CHANGED_DEVICES[@]}"; do
    local device_path="/dev/input/event$device"
    sudo chown root:input "$device_path" "$device_path"
    sudo chmod 660 "$device_path" "$device_path"
  done
}

primary_gamescope() {
  eval "$GAMESCOPE_BIN $GAMESCOPE_PARAMS -- $STEAM_BIN $STEAM_PARAMS"
  GAMESCOPE_PRIMARY_PID=$!
}

secondary_gamescope() {
  eval "sudo $RUNAS_BIN -X $RUNAS_ACC -- env PULSE_SERVER=tcp:127.0.0.1:4713 $GAMESCOPE_BIN $GAMESCOPE_PARAMS -- $STEAM_BIN $STEAM_PARAMS"
  GAMESCOPE_SECONDARY_PID=$!
}

trap cleanup EXIT INT TERM

main() {
  echo "DualScope by NaviVani "

  if [[ $EUID -eq 0 ]]; then
    echo "Running as sudo, exiting..."
    exit 1
  fi

  for bin in "$GAMESCOPE_BIN" "$STEAM_BIN" "$RUNAS_BIN"; do
    if [[ ! -x "$bin" ]]; then
      echo "The $bin executable was not found, exiting..."
      exit 1
    fi
  done

  get_devices_to_change "$(whoami)"
  get_devices_to_change "$RUNAS_ACC"

  echo "Killing steam before starting..."
  pkill steam

  while pgrep steam > /dev/null; do
    sleep 1
  done

  startup

  echo "Opening gamescope sessions!"
  secondary_gamescope &
  primary_gamescope
}

main "$@"

Thanks for this script, I'm having one small issue though. I'm on Nobara Linux (copied over the run-as.py and enable_graphical_services.sh) and everything seems to work fine. But I can't lock input to specific users. As in, the controller controls both instances and the keyboard+Mouse control both instances as well. Any help would be appreciated.

I've been using AI to try to help me but it sends me down pointless rabbithole after pointless rabbithole, chasing my tail on things that didn't need fixing in the first place.