commit d7e12e55b0bce62ac3499953d3cbcd13e8ca20d1
from: Oliver Lowe <oliver.lowe@audinate.com>
via: Oliver Lowe <o@olowe.co>
date: Sat Apr 05 07:06:16 2025 UTC

backlight: add for Linux

commit - cc1e3d0b494763ae4647ad6bbfd8a1d6c1537db9
commit + d7e12e55b0bce62ac3499953d3cbcd13e8ca20d1
blob - aaa322f78365fa1a52272d631ca5b71708b5d252
blob + e8883cff4096081b1cb191ac3aa62a543f442cb4
--- README
+++ README
@@ -4,6 +4,7 @@ To install, run install.sh.
 
 The following commands are provided:
 
+- backlight - set backlight brightness
 - bbsnip - create a snippet on BitBucket
 - hits - count web traffic
 - hlsget - download the contents of a HLS playlist
blob - /dev/null
blob + a7b61d4d13c24e20270561c5380281e4ebbafbb9 (mode 755)
--- /dev/null
+++ bin/backlight
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+dir=/sys/class/backlight/intel_backlight
+if ! test -e $dir
+then
+	echo $dir does not exist 1>&2
+	exit 1
+fi
+
+pct="0.$1"
+if test $1 -eq 100
+then
+	pct=1
+fi
+
+max=`cat $dir/max_brightness`
+echo $pct $max | awk '{
+	x = $1 * $2
+	print int(x)
+}' > $dir/brightness
blob - /dev/null
blob + 45374c101c4f887b05c91f213173dd7d033e24f8 (mode 644)
--- /dev/null
+++ man/backlight.1
@@ -0,0 +1,24 @@
+.Dd
+.Dt BACKLIGHT 1
+.Sh NAME
+.Nm backlight
+.Nd set backlight brightness
+.Sh SYNOPSIS
+.Nm
+.Ar percent
+.Sh DESCRIPTION
+.Nm
+sets the backlight device brightness to the given percentage of the maximum.
+.Sh EXAMPLE
+Set maximum brightness,
+then go back down to 50% brightness:
+.Bd -literal -offset Ds
+backlight 100
+backlight 50
+.Ed
+.Sh FILES
+.Pa /sys/class/backlight
+.Sh EXIT STATUS
+.Ex
+.Sh SEE ALSO
+.Xr sysfs 5