#!/bin/bash

# brightness + on my thinkpad

max=$(cat /sys/class/backlight/intel_backlight/max_brightness)
echo "Max: $max"
min=0
echo "Min: $min"
value=250
echo "Value: $value"
actual=$(cat /sys/class/backlight/intel_backlight/actual_brightness)
echo "Actual: $actual"
future=$(($actual+$value))
if [ $future -gt $max ]; then
    future=$max
fi
echo "Future: $future"
tee /sys/class/backlight/intel_backlight/brightness <<< $future