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 July 19, 2022 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 q 34.Op Fl f Ar device 35.Nm 36.Op Fl q 37.Op Fl f Ar device 38.Fl i 39.Nm 40.Op Fl f Ar device 41.Ar value 42.Nm 43.Op Fl f Ar device 44.Cm incr Ns | Ns Cm + 45.Op Ar value 46.Nm 47.Op Fl f Ar device 48.Cm decr Ns | Ns Cm - 49.Op Ar value 50.Sh DESCRIPTION 51The 52.Nm 53utility can be used to configure brightness levels for registered backlights. 54.Pp 55Called without any arguments it will print the current brightness level 56of the first registered backlight. 57.Pp 58The options are as follows: 59.Bl -tag -width "-f device" 60.It Fl f Ar device 61Device to operate on. 62If not specified, 63.Pa /dev/backlight/backlight0 64is used. 65If an unqualified name is provided, 66.Pa /dev/backlight/ 67is automatically prepended. 68.It Fl i 69Query information about the backlight (name, type). 70.It Fl q 71When querying the brightness level only print the value. 72.It Ar value 73Set the brightness level to this value, must be between 0 and 100. 74A trailing 75.Dq % 76is valid. 77.It Cm incr Ns | Ns Cm + Op Ar value 78Decrement the backlight level. 79If no value is specified a default of 10 percent is used. 80.It Cm decr Ns | Ns Cm - Op Ar value 81Increment the backlight level. 82If no value is specified a default of 10 percent is used. 83.El 84.Sh EXAMPLES 85Show the current brightness level: 86.Bd -literal -offset indent 87$ backlight -f /dev/backlight/backlight0 88brightness: 98 89.Ed 90.Sh SEE ALSO 91.Xr backlight 9 92.Sh HISTORY 93The 94.Nm 95utility appeared in 96.Fx 13.0 . 97.Sh AUTHORS 98.An -nosplit 99The 100.Nm 101utility and this manual page were written by 102.An Emmanuel Vadot Aq Mt manu@FreeBSD.org . 103