#!/bin/zsh
cd /sys/class/backlight
export counter=1
for adapter in `ls`;do
cd $adapter
export max=`cat max_brightness`
cd ..
export counter=$(($counter+1))
case "$1" in
"off")
echo 0 > /sys/class/backlight/$adapter/brightness
;;
"on")
echo $max>/sys/class/backlight/$adapter/brightness
;;
esac
done