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.Dd July 19, 2022 24.Dt BACKLIGHT 8 25.Os 26.Sh NAME 27.Nm backlight 28.Nd configure backlight hardware 29.Sh SYNOPSIS 30.Nm 31.Op Fl q 32.Op Fl f Ar device 33.Nm 34.Op Fl q 35.Op Fl f Ar device 36.Fl i 37.Nm 38.Op Fl f Ar device 39.Ar value 40.Nm 41.Op Fl f Ar device 42.Cm incr Ns | Ns Cm + 43.Op Ar value 44.Nm 45.Op Fl f Ar device 46.Cm decr Ns | Ns Cm - 47.Op Ar value 48.Sh DESCRIPTION 49The 50.Nm 51utility can be used to configure brightness levels for registered backlights. 52.Pp 53Called without any arguments it will print the current brightness level 54of the first registered backlight. 55.Pp 56The options are as follows: 57.Bl -tag -width "-f device" 58.It Fl f Ar device 59Device to operate on. 60If not specified, 61.Pa /dev/backlight/backlight0 62is used. 63If an unqualified name is provided, 64.Pa /dev/backlight/ 65is automatically prepended. 66.It Fl i 67Query information about the backlight (name, type). 68.It Fl q 69When querying the brightness level only print the value. 70.It Ar value 71Set the brightness level to this value, must be between 0 and 100. 72A trailing 73.Dq % 74is valid. 75.It Cm incr Ns | Ns Cm + Op Ar value 76Decrement the backlight level. 77If no value is specified a default of 10 percent is used. 78.It Cm decr Ns | Ns Cm - Op Ar value 79Increment the backlight level. 80If no value is specified a default of 10 percent is used. 81.El 82.Sh EXAMPLES 83Show the current brightness level: 84.Bd -literal -offset indent 85$ backlight -f /dev/backlight/backlight0 86brightness: 98 87.Ed 88.Sh SEE ALSO 89.Xr backlight 9 90.Sh HISTORY 91The 92.Nm 93utility appeared in 94.Fx 13.0 . 95.Sh AUTHORS 96.An -nosplit 97The 98.Nm 99utility and this manual page were written by 100.An Emmanuel Vadot Aq Mt manu@FreeBSD.org . 101