Compile & install
sudo make install
Usage
.Increase brightness by 100
sudo brightness 100
.Decrease brightness by 100
sudo brightness -100
Sadly to make this working you need to have root permissions.
You can either put sudo and write password before each run or put:
your_user_name ALL=(ALL) NOPASSWD: /usr/bin/brightness
To run it with sudo but without need to type your password.
Why?
I needed a simple program that will change brightness for my dwm window manager.
I'm pretty sure this won't work for all cases as hardware can be different
but for my HP laptop it's working fine.