#!/bin/bash
set -e
EXTERNAL="$(xrandr | grep 'DisplayPort.* connected' | cut -d' ' -f1)"
[ -z "$EXTERNAL" ] && exit 1

BRIGHTNESS="$(xrandr --verbose | grep -A5 "$EXTERNAL" | grep Brightness | cut -d':' -f2)"
if [ "$BRIGHTNESS" == " 1.0" ]; then
	xrandr --output $EXTERNAL --brightness 0
else
	xrandr --output $EXTERNAL --brightness 1
fi