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Revision as of 15:28, 18 November 2012 by Haikarainen (talk | contribs) (Usage)
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Light is a program used to easily control a screens backlight-controllers. It is the successor of LightScript, and is also its official C-port.


Light is a bit heavier than LightScript, but still pretty minimal. It features:

  • Automatically finds the controller with the best resolution, and uses it to set the brightness.
  • Uses a minimum cap of 5% lightness as standard, which can be easily changed using the /etc/light/minlight file. (Some controllers will turn the screen pitchblack on 0%)
  • Is very forgiving on "bad systems", while still doing a lot of safety-checks. Also allows you to override the controller-detection and decide what controller you would like to use by the /etc/light/override-file.


It is available on AUR where it goes by the name lightAUR, the only runtime-dependency it has is glibc, and the only build-dependency it has is git. For manual install, see


To see full usage, just type;

$ light --help

Basic usage follows:

// Set the brightness of the screen to 30%
$ light 30
// Increase brightness by 10% and suppress output
$ light -aq 10
// Print the current brightness in percent (unprecise)
$ light -c

To override the default minimum-cap of 5%, just put an unsigned integer into /etc/light/minlight.

To override the controller-detection and decide what controller to use, put the controllers filename into /etc/light/override, for example if the controller is "/sys/class/backlight/intel_backlight/", you put "intel_backlight" (without quotes) into /etc/light/override.

Protip: To make light executable by users who aren't root (to replace the auto-sudo lightscript has), issue the following commands as root after it is installed:

$ chown root /etc/light/light
$ chmod a+xs /etc/light/light


Please give bugs/feedback directly on the AUR-page comments.