Script for changing brightness in Linux based systems

brightness.sh

#!/bin/bash

# It's necessary give the correct permissions for the brightness file
# Verify the correct path to the brightness file on your pc

# Parameters: "inc" for increment and "dec" for decrement brightness

#get the current brightness
current=`cat /sys/class/backlight/intel_backlight/actual_brightness`

# sum or subtract 10 from current brightness
if [ "$1" == "inc" ]; then
    current=$(expr $current + 10)
elif [ "$1" == "dec" ]; then
    current=$(expr $current - 10)
fi

#save the current brightness
`echo $current > /sys/class/backlight/intel_backlight/brightness`

Giving the correct permission: sudo chown your_user /sys/class/backlight/intel_backlight/brightness

Example usage for increment brightness in 10 units: ./brightness.sh inc 10

Thanks for the script :)

You can also add this to your /etc/sudoers

<user> ALL= NOPASSWD: /usr/local/bin/<your-brightness-script>