Add backlight script

1 files changed, 26 insertions, 0 deletions

diff --git a/backlight b/backlight
new file mode 100755
index 0000000..2d5e0e2
--- /dev/null
+++ b/backlight
@@ -0,0 +1,26 @@
+#!/bin/bash
+
+# Allows you to adjust display backlight from the command line.
+# USAGE: backlight <brightness change>
+# The brightness change can be positive (for brighter) or negative (for darker).
+# NOTE: requires root privileges.
+
+brightness=`cat /sys/class/backlight/intel_backlight/brightness`
+delta="$1"
+
+if [[ ! $delta =~ ^-?[0-9]+$ ]]; then
+    echo "Not a number!"
+    exit 1
+fi
+
+new_brightness=$((brightness + delta))
+
+
+if [[ new_brightness -gt 7500 ]]; then
+    new_brightness=7500
+elif [[ new_brightness -lt 0 ]]; then
+    new_brightness=0
+fi
+
+# echo $new_brightness
+tee /sys/class/backlight/intel_backlight/brightness <<< "$new_brightness"