light — a program to control backlight controllers

Authors

       Copyright © 2012-2018 Fredrik Haikarainen

       This is free software, see the source for copying  conditions.   There  is  NO  warranty;  not  even  for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE

GNU/Linux                                        August 4, 2018                                         LIGHT(1)

Commands

       The following unique commands are supported:

       -H, -h  Show help text and exit

       -V      Show program version and exit

       -L      List available devices

       -A      Increase brightness by value

       -U      Decrease brightness by value

       -S      Set brightness to value

       -G      Get brightness, default

       -N      Set minimum brightness to value

       -P      Get minimum brightness

       -O      Save current brightness

       -I      Restore previously saved brightness

Description

light is a program to control backlight display and keyboard controllers under GNU/Linux.

       •   Operates independently of X (X-Window)
       •   Can automatically figure out the best controller to use, making full use of the underlying hardware
       •   Supports a minimum cap on the brightness value, as some controllers set the display to be pitch black
           at a vaĺue of 0 (or higher)

Files

       When  run  in  its classic SUID root mode light caches settings and current brightness in /etc/light.  In
       its non-privileged mode of operation the ~/.cache/light directory is used instead.

Name

       light — a program to control backlight controllers

Options

       The behavior of the above commands can be modified using these options:

       -r      Interpret input and output values in raw mode

       -sPATH
               Specify device target path.  Use -L to list available devices

       -vLEVEL
               Set verbosity level, by default light only outputs read values:

               0:  Read values
               1:  Read values, Errors
               2:  Read values, Errors, Warnings
               3:  Read values, Errors, Warnings, Notices