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.Dd July 19, 2022 .Dt BACKLIGHT 8 .Os .Sh NAME .Nm backlight .Nd configure backlight hardware .Sh SYNOPSIS .Nm .Op Fl q .Op Fl f Ar device .Nm .Op Fl q .Op Fl f Ar device .Fl i .Nm .Op Fl f Ar device .Ar value .Nm .Op Fl f Ar device .Cm incr Ns | Ns Cm + .Op Ar value .Nm .Op Fl f Ar device .Cm decr Ns | Ns Cm - .Op Ar value .Sh DESCRIPTION The .Nm utility can be used to configure brightness levels for registered backlights.
p Called without any arguments it will print the current brightness level of the first registered backlight.
p The options are as follows: l -tag -width "-f device" t Fl f Ar device Device to operate on. If not specified,
a /dev/backlight/backlight0 is used. If an unqualified name is provided,
a /dev/backlight/ is automatically prepended. t Fl i Query information about the backlight (name, type). t Fl q When querying the brightness level only print the value. t Ar value Set the brightness level to this value, must be between 0 and 100. A trailing .Dq % is valid. t Cm incr Ns | Ns Cm + Op Ar value Decrement the backlight level. If no value is specified a default of 10 percent is used. t Cm decr Ns | Ns Cm - Op Ar value Increment the backlight level. If no value is specified a default of 10 percent is used. .El .Sh EXAMPLES Show the current brightness level: d -literal -offset indent $ backlight -f /dev/backlight/backlight0 brightness: 98 .Ed .Sh SEE ALSO .Xr backlight 9 .Sh HISTORY The .Nm utility appeared in .Fx 13.0 . .Sh AUTHORS .An -nosplit The .Nm utility and this manual page were written by .An Emmanuel Vadot Aq Mt manu@FreeBSD.org .