Provided by: xbacklight_1.2.1-1build1_amd64
xbacklight - adjust backlight brightness using RandR extension
xbacklight [-help] [-display display] [-get] [-set percent] [-inc percent] [-dec percent]
Xbacklight is used to adjust the backlight brightness where supported. It finds all outputs on the X server supporting backlight brightness control and changes them all in the same way. -get Print out the current backlight brightness of each output with such a control. The brightness is represented as a percentage of the maximum brightness supported. -set percent Sets each backlight brightness to the specified level. -inc percent Increases brightness by the specified amount. -dec percent Decreases brightness by the specified amount. -help Print out a summary of the usage and exit. -time milliseconds Length of time to spend fading the backlight between old and new value. Default is 200. -steps number Number of steps to take while fading. Default is 20.
Keith Packard, Open Source Technology Center, Intel Corporation.