NIT

Nit is a backlight manager for screen and keyboard.

Understanding

Nit uses a different controller for each device that can handle the brightness.

The screen controller is loaded from /sys/class/backlight and it is by default nv_backlight. This value can be overwritten setting the environment variable $NIT_CTRL_SCREEN.

The keyboard controller is loaded from /sys/class/leds and it is by default smc::kbd_backlight. This value can be overwritten setting the environment variable $NIT_CTRL_KEYBOARD.

Installing

The first step consists in downloading, compiling and installing the source:

$ git clone https://github.com/matteocellucci/nit.git
$ cd nit
$ make clean && make && sudo make install

In the second step you may need to set the enviroment variables accordingly with your controllers name. You can find them listing files in their loadings folder:

$ export $NIT_CTRL_SCREEN="<screen_ctrl_name>"
$ export $NIT_CTRL_KEYBOARD="<keyboard_ctrl_name>"

Warning: besides current session, in order to make these settings persistent after reboot, you should add those commands in a file such rc.local.

The installation is complete, but Nit can run only with sudo permission due to the mode set of the controller. To allow for the logged user to use it a further step is needed. Execute:

$ sudo nit --setup

Warning: to make changes available you must fullfill a reboot or at least a login/logout.

Uninstalling

Simply:

$ cd nit
$ make unistall

Usage excerpt

nit [DEVICE] [OPTION]

Option:
  -h, --help             display this help and exit
  -l, --list             list controllers names
      --setup            need root permission; generate rules to control
                         brightness; this option will be executed first; see
                         PERMISSIONS for more details
  -s [VAL], --set=[VAL]  adjust brightness according to VAL; VAL is an integer
                         and can be formatted in three ways. Each of them is
                         meaningfull:
                             VAL    set VAL as current brightness
                            +VAL    add VAL to current brightness
                            -VAL    sub VAL from current brightness
  -S, --silent-mode      don't print feedback brightness value after '-s'
  -v, --version          output version information and exit

Device:
  --screen               select screen controller
  --keyboard             select keyboard controller

Example

Add 30 points of brightness to the screen

$ nit --screen -s +30

Set to 200 the keyboard brightness

$ nit --keyboard -s 200

Subtract 4 points of brightness to the screen

$ nit --screen -s -4

Contribution

Contributions to Nit are greatly appreciated, whether it's a feature request or a bug report. You can make magic trick even by yourself. I'll enjoy if you request a pull!