1.\" Copyright (c) 2020 Emmanuel Vadot <manu@freebsd.org> 2.\" 3.\" Redistribution and use in source and binary forms, with or without 4.\" modification, are permitted provided that the following conditions 5.\" are met: 6.\" 1. Redistributions of source code must retain the above copyright 7.\" notice, this list of conditions and the following disclaimer. 8.\" 2. Redistributions in binary form must reproduce the above copyright 9.\" notice, this list of conditions and the following disclaimer in the 10.\" documentation and/or other materials provided with the distribution. 11.\" 12.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 13.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 14.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 15.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 16.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 17.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 18.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 19.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 20.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 21.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 22.\" 23.\" $FreeBSD$ 24.\" 25.Dd March 03, 2021 26.Dt BACKLIGHT 8 27.Os 28.Sh NAME 29.Nm backlight 30.Nd configure backlight hardware 31.Sh SYNOPSIS 32.Nm 33.Op Fl f Ar device 34.Op Fl i 35.Op Fl q 36.Op Ar value 37.Nm 38.Op Fl f Ar device 39.Cm incr Ns | Ns Cm + 40.Op Ar value 41.Nm 42.Op Fl f Ar device 43.Cm decr Ns | Ns Cm - 44.Op Ar value 45.Sh DESCRIPTION 46The 47.Nm 48utility can be used to configure brightness levels for registered backlights. 49.Pp 50Called without any arguments it will print the current brightness level 51of the first registered backlight. 52.Pp 53The options are as follows: 54.Bl -tag -width "-f device" 55.It Fl f Ar device 56Device to operate on. 57If not specified, 58.Pa /dev/backlight/backlight0 59is used. 60If an unqualified name is provided, 61.Pa /dev/backlight 62is automatically prepended. 63.It Fl i 64Query information about the backlight (name, type). 65.It Fl q 66When querying the brightness level only print the value. 67.It Ar value 68Set the brightness level to this value, must be between 0 and 100. 69A trailing 70.Dq % 71is valid. 72.It Cm incr Ns | Ns Cm + Op Ar value 73Decrement the backlight level. 74If no value is specified a default of 10 percent is used. 75.It Cm decr Ns | Ns Cm - Op Ar value 76Increment the backlight level. 77If no value is specified a default of 10 percent is used. 78.El 79.Sh EXAMPLES 80Show the current brightness level 81.Bd -literal -offset indent 82backlight -f /dev/backlight/backlight0 83.Ed 84.Sh SEE ALSO 85.Xr backlight 9 86.Sh HISTORY 87The 88.Nm 89utility appeared in 90.Fx 13.0 . 91.Sh AUTHORS 92.An -nosplit 93The 94.Nm 95utility and this manual page were written by 96.An Emmanuel Vadot Aq Mt manu@FreeBSD.org . 97