commit c1b55d90aaaf4dda8531994ae03fcd458bd3aff9
Author: Luca <lucaux@tutanota.com>
Date:   Sat May 7 13:43:37 2022 +0100

    runit

diff --git a/finish b/finish
new file mode 100755
index 0000000..5b1be99
--- /dev/null
+++ b/finish
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+[ -d '/var/cache/backlight/' ] || mkdir -p '/var/cache/backlight'
+[ -w '/var/cache/backlight/' ] || chmod 755 '/var/cache/backlight/'
+
+# Save current brightness of each card.
+for card in `find /sys/class/backlight/ -type l`; do
+    cp "$card/brightness" "/var/cache/backlight/$(basename $card)-brightness-old"
+done
diff --git a/install b/install
new file mode 100755
index 0000000..3b8c489
--- /dev/null
+++ b/install
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+doas mkdir -p /etc/runit/sv/backlight/
+
+doas cp -r run /etc/runit/sv/backlight 
+doas cp -r finish /etc/runit/sv/backlight
+
+doas ln -s /etc/runit/sv/backlight /run/runit/service/
+
diff --git a/run b/run
new file mode 100755
index 0000000..2373dfe
--- /dev/null
+++ b/run
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+# Restore saved brightness for each card, if any.
+for card in $(find /sys/class/backlight/ -type l); do
+    storage_file="/var/cache/backlight/$(basename $card)-brightness-old"
+    if [ -r "$storage_file" ]; then
+        cp "$storage_file" "$card/brightness"
+    fi
+done
+
+exec chpst -b backlight pause