NAME

     light — a program to control backlight controllers

SYNOPSIS

     light [OPTIONS] [VALUE]

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)

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

OPTIONS

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

     -r      Interpret input and output values in raw mode

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

     -v LEVEL
             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

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.

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