.Dd $Mdocdate$
.Dt BRI 1
.Os "Causal Agency"
.Sh NAME
.Nm bri
.Nd backlight brightness control
.Sh SYNOPSIS
.Nm bri Op Ar brightness
.Nm bri Cm +
.Nm bri Cm -
.Sh DESCRIPTION
.Nm
controls the backlight brightness on Linux.
.Pp
With no argument,
the current brightness is printed.
With a numerical
.Ar brightness
argument,
the brightness is set.
.Pp
The
.Cm +
and
.Cm -
arguments
may be repeated any number of times
and adjust the brightness
in increments of 16.
.Sh FILES
.Bl -tag
.It Pa /sys/class/backlight
Files under the first subdirectory found
are used to control the backlight brightness.
.El