#!/bin/bash

error="Usage: $0 up | $0 down"
xbl=`xbacklight`
limite1=2
limite2=10
limite3=40
limite4=100

if [ "$#" -eq 1 ]
	then
	if [ $1 = "up" ]
		then
		# Augmenter le rétroéclairage
		if [ $(echo "$xbl == $limite4"|bc) -eq 1 ]
				then
				echo "Rétroéclairage au maximum !"
				xbacklight = 100
			else
			if [ $(echo "$xbl < $limite2"|bc) -eq 1 ]
					then
					xbacklight +1
				else
				if [ $(echo "$xbl < $limite3"|bc) -eq 1 ]
						then
						xbacklight +10
					else
					xbacklight +20
				fi
			fi
		fi
	elif [ $1 = "down" ]
		then
		# Diminuer le rétroéclairage
		if [ $(echo "$xbl < $limite1"|bc) -eq 1 ]
				then
				echo "Rétroéclairage au minimum !"
				xbacklight =1
			else
			if [ $(echo "$xbl < $limite2"|bc) -eq 1 ]
					then
					xbacklight -1
				else
				if [ $(echo "$xbl < $limite3"|bc) -eq 1 ]
						then
						xbacklight -10
					else
					xbacklight -20
				fi
			fi
		fi
		else
		echo $error
	fi
	else
	echo $error
fi
exit