Man1 - xbacklight.1

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.

-version

Print out the program version 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.

Xrandr(3)

Keith Packard, Open Source Technology Center, Intel Corporation.