.Dd September 7, 2018 .Dt BRI 1 .Os . .Sh NAME .Nm bri .Nd backlight brightness control . .Sh SYNOPSIS .Nm .Op Ar brightness .Nm .Cm + .Nm .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