#!/bin/bash brightness="/sys/class/backlight/acpi_video0/brightness" presbright=`cat /sys/class/backlight/acpi_video0/brightness` perc=`expr $presbright "*" 100 "/" 15` case "$1" in up) echo $(( ${presbright} + 1 )) > $brightness sudo -u $user notify-send " " -i notification-display-brightness-low -h int:value:$perc -h string:x-canonical-private-synchronous:brightness & ;; down) echo $(( ${presbright} - 1 )) > $brightness sudo -u $user notify-send " " -i notification-display-brightness-low -h int:value:$perc -h string:x-canonical-private-synchronous:brightness & ;; status) echo $presbright ;; *) echo "Accepted arguments are: up, down, status." ;; esac exit 0