BACKLIGHT(8)            FreeBSD System Manager's Manual           BACKLIGHT(8)

NAME
     backlight - configure backlight hardware

SYNOPSIS
     backlight [-f device] [-i] [-q] [value]
     backlight [-f device] incr|+ [value]
     backlight [-f device] decr|- [value]

DESCRIPTION
     The backlight utility can be used to configure brightness levels for
     registered backlights.

     If call without any option it will print the current brightness level of
     the first registered backlight.

     The options are as follows:

     -f device  Device to operate on.  If not specified,
                /dev/backlight/backlight0 is used.  If an unqualified name is
                provided, /dev/backlight is automatically prepended.

     -i         Query information about the backlight (name, type).

     -q         When querying the brightness level only print the value.

     value      Set the brightness level to this value, must be between 0 and
                100.  A trailing "%" is valid.

     incr|+ [value]
                Decrement the backlight level.  If no value is specified a
                default of 10 percent is used.

     decr|- [value]
                Increment the backlight level.  If no value is specified a
                default of 10 percent is used.

EXAMPLES
     Show the current brightness level

           backlight -f /dev/backlight/backlight0

SEE ALSO
     backlight(9)

HISTORY
     The backlight utility appeared in FreeBSD 13.0.

AUTHORS
     The backlight utility and this manual page were written by Emmanuel Vadot
     <manu@FreeBSD.org>.

FreeBSD 13.1-RELEASE-p6          March 3, 2021         FreeBSD 13.1-RELEASE-p6