XBACKLIGHT(1)

NAME
xbacklight - adjust display and keyboard backlight using the /sys filesystem

SYNOPSIS
xbacklight [-h|-help] [-ctrl CTRL] [-display IGNORED] [-time MILLISECS] [-steps STEPS | -fps FPS] ...

xbacklight [flags] -list
xbacklight [flags] -get | -getf
xbacklight [flags] -set PERCENT | -inc PERCENT | -dec PERCENT
xbacklight [flags] [=]PERCENT | +PERCENT | -PERCENT

DESCRIPTION
xbacklight can query or set the brightness of display and keyboard backlight. xbacklight operates on the first device found in /sys/class/backlight, unless told otherwise. Use -list to see the full list of available devices that can be controlled; then use the -ctrl flag to control them individually.

QUERY OPERATIONS

-list
    Print the list of controllable devices.

-get
    Print out the backlight brightness as an percentage of the maximum brightness supported.

-getf
    Same as -get, but without rounding.

SET OPERATIONS
Both integer and fractional values are accepted when specifying the brightness percentage. Regular set flags:

-set PERCENT
    Sets the backlight brightness to the specified percentage level.

-inc PERCENT
    Increases brightness by the specified amount.

-dec PERCENT
    Decreases brightness by the specified amount.

Set operations using positional arguments:

xbacklight PERCENT
xbacklight =PERCENT
    Set brightness (same as -set PERCENT).

xbacklight +PERCENT
    Increase brightness (same as -inc PERCENT).

xbacklight -PERCENT
    Decrease brightness (same as -dec PERCENT).

OPTIONS

-h, -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. Specifying either the number of fading steps (with -steps) or fading frame rate (with -fps) is required to actually perform fading.

-steps STEPS
    Number of fading steps.

-fps FPS
    Target frame rate (frames/steps per second).

-display IGNORED
    Ignored for backward compatibility.

-ctrl CONTROLLER
    Set the device name to operate on.

NOTES
xbacklight doesn't lock the backlight device during fading. Running two concurrent fading operations will result in backlight flickering.

AUTHORS
xbacklight is part of acpilight (https://github.com/wavexx/acpilight) and is distributed under GPLv3+ WITHOUT ANY WARRANTY.
Copyright(c) 2016-2017 by wave++ "Yuri D'Elia" <wavexx@thregr.org>.