#!/bin/sh

# script to decrease the display brightness by $1%

[ -z "$1" ] && echo "Error: please give percent as argument" && exit 1

#xbacklight -dec "$1"
#exit

device=$(brightnessctl -l | grep "class 'backlight'" | tail -n +3 | awk '{print $2}' | tr -d "'")
if brightnessctl -l | grep "class 'backlight'" | grep -q "^Device 'intel_backlight'"; then
    device="intel_backlight"
fi

brightness=$(brightnessctl -d "${device}" | grep Current | awk -F '[)(]' "{print \$2 - $1}")

brightnessctl -d "${device}" set "$brightness"%