brightness

#!/bin/sh
if [ $# -eq 0 ]; then
	for d in /sys/class/backlight/*; do
		echo "$d: $(cat "$d/brightness")"
	done
elif [ $# -eq 1 ]; then
	for d in /sys/class/backlight/*; do
		echo $1 > "$d/brightness"
	done
else
	echo "Usage: $0 [level]"
	exit 1
fi