From: Oleg Broytman <phd@phdru.name>
Date: Sat, 5 Jul 2025 11:24:27 +0000 (+0300)
Subject: LCD scripts: allow to increse/decrease brightness
X-Git-Url: https://git.phdru.name/dotfiles.git/?a=commitdiff_plain;h=HEAD;p=dotfiles.git

LCD scripts: allow to increse/decrease brightness
---

diff --git a/admin/prog/acpi/LCD b/admin/prog/acpi/LCD
index 40f6a2f..23f6a2f 100755
--- a/admin/prog/acpi/LCD
+++ b/admin/prog/acpi/LCD
@@ -1,9 +1,22 @@
 #!/bin/sh -e
 
-if [ -z "$1" ]; then
+current=`cat /sys/class/backlight/intel_backlight/brightness`
+
+if [ -z "$1" -o -n "$2" ]; then
    echo "Usage: $0 brightness [0-`cat /sys/class/backlight/intel_backlight/max_brightness`]" >&2
-   echo "Current: `cat /sys/class/backlight/intel_backlight/brightness`"
+   echo "Current: $current"
    exit 1
 fi
 
-echo "$1" > /sys/class/backlight/intel_backlight/brightness
+case "$1" in
+   +*)
+       new=`echo $1 | sed 's/^+//'`
+       new=`expr $current + $new` ;;
+   -*)
+       new=`echo $1 | sed 's/^-//'`
+       new=`expr $current - $new` ;;
+    *) new="$1" ;;
+esac
+
+echo "$new" |
+    sudo tee /sys/class/backlight/intel_backlight/brightness >/dev/null
diff --git a/admin/prog/acpi/LCD% b/admin/prog/acpi/LCD%
index 675a5ef..bb817a7 100755
--- a/admin/prog/acpi/LCD%
+++ b/admin/prog/acpi/LCD%
@@ -1,19 +1,30 @@
 #!/bin/sh -e
 
 max=`cat /sys/class/backlight/intel_backlight/max_brightness`
+current=`cat /sys/class/backlight/intel_backlight/brightness`
+current_percent=`expr $current \* 100 / $max`
 
-if [ -z "$1" ]; then
+if [ -z "$1" -o -n "$2" ]; then
    echo "Usage: $0 brightness [10-100]" >&2
-   current=`cat /sys/class/backlight/intel_backlight/brightness`
-   current_percent=`expr $current \* 100 / $max`
    echo "Current: $current_percent%"
    exit 1
 fi
 
-if [ "$1" -lt 10 -o "$1" -gt 100 ]; then
+case "$1" in
+   +*)
+        new=`echo $1 | sed 's/^+//'`
+        new=`expr $current_percent + $new` ;;
+   -*)
+        new=`echo $1 | sed 's/^-//'`
+        new=`expr $current_percent - $new` ;;
+    *) new="$1" ;;
+esac
+
+if [ "$new" -lt 10 -o "$new" -gt 100 ]; then
    echo "Usage: $0 brightness 10-100" >&2
    exit 1
 fi
 
-new=`expr $max \* $1 / 100`
-echo "$new" > /sys/class/backlight/intel_backlight/brightness
+new=`expr $max \* $new / 100`
+echo "$new" |
+    sudo tee /sys/class/backlight/intel_backlight/brightness >/dev/null