bright

#!/bin/bash
# Author: CrazyA
# Needed something for my HP dm1 because brightness keys didn't work out of the box
#
# Add this to your /etc/rc.local so we can actually write here as a regular user
# chmod go+w /sys/class/backlight/acpi_video0/brightness
#
# Bind 'bright -' and 'bright +' to some keyboard shortcuts and enjoy
#
CURRENT=`cat /sys/class/backlight/acpi_video0/brightness`
if [ -z "$1" ]; then
  echo $CURRENT
else
  if [ $1 = "+" ]; then
    MAX=`cat /sys/class/backlight/acpi_video0/max_brightness`
    if [ $CURRENT -lt $MAX ]; then
      NEW=$(expr $CURRENT + 1)
      echo $NEW > /sys/class/backlight/acpi_video0/brightness
      echo $NEW
    else
      echo $CURRENT
    fi
  else
    if [ $CURRENT -gt 0 ]; then
      NEW=$(expr $CURRENT - 1)
      echo $NEW > /sys/class/backlight/acpi_video0/brightness
      echo $NEW
    else
      echo $CURRENT
    fi
  fi
fi