#!/bin/bash

FILE=""
CURLIGHT=`xbacklight | cut -d '.' -f1`

echo $CURLIGHT

echo $(($CURLIGHT +10))


if [ "$1" = "+" ] ;
then
	if [ $CURLIGHT -ge 0 ] && [ $CURLIGHT -lt 10 ]
	then 
		xbacklight =20
	elif [ $CURLIGHT -gt 9 ] && [ $CURLIGHT -lt 20 ]
	then
		xbacklight =30
	elif [ $CURLIGHT -gt 19 ] && [ $CURLIGHT -lt 30 ]
	then
		xbacklight =40
	elif [ $CURLIGHT -gt 29 ] && [ $CURLIGHT -lt 40 ]
	then
		xbacklight =50
	elif [ $CURLIGHT -gt 39 ] && [ $CURLIGHT -lt 50 ]
	then
		xbacklight =60
	elif [ $CURLIGHT -gt 49 ] && [ $CURLIGHT -lt 60 ]
	then
		xbacklight =70
	elif [ $CURLIGHT -gt 59 ] && [ $CURLIGHT -lt 70 ]
	then
		xbacklight =80
	elif [ $CURLIGHT -gt 69 ] && [ $CURLIGHT -lt 80 ]
	then
		xbacklight =90
	elif [ $CURLIGHT -gt 79 ] && [ $CURLIGHT -lt 90 ]
	then
		xbacklight =100
	else
		xbacklight =100
	fi
elif [ "$1" = "-" ] ;
then 
	if [ $CURLIGHT -ge 0 ] && [ $CURLIGHT -lt 10 ]
	then 
		xbacklight =0
	elif [ $CURLIGHT -gt 9 ] && [ $CURLIGHT -lt 20 ]
	then
		xbacklight =10
	elif [ $CURLIGHT -gt 19 ] && [ $CURLIGHT -lt 30 ]
	then
		xbacklight =20
	elif [ $CURLIGHT -gt 29 ] && [ $CURLIGHT -lt 40 ]
	then
		xbacklight =30
	elif [ $CURLIGHT -gt 39 ] && [ $CURLIGHT -lt 50 ]
	then
		xbacklight =40
	elif [ $CURLIGHT -gt 49 ] && [ $CURLIGHT -lt 60 ]
	then
		xbacklight =50
	elif [ $CURLIGHT -gt 59 ] && [ $CURLIGHT -lt 70 ]
	then
		xbacklight =60
	elif [ $CURLIGHT -gt 69 ] && [ $CURLIGHT -lt 80 ]
	then
		xbacklight =70
	elif [ $CURLIGHT -gt 79 ] && [ $CURLIGHT -lt 90 ]
	then
		xbacklight =80
	else
		xbacklight =90
	fi
else
	echo "Invalid argument. expected '+' or '-'"
fi