[solved] XFCE: bind custom script to backlight keys, including Notify?

Question

Hello, the situation is as follows:
My (Toshiba Z30) backlight keys toggle the XFCE-brightness control popup, but they don't control the display brightness.
I found out why: they control /sys/class/backlight/toshiba/brightness instead of /sys/class/backlight/intel_backlight/brightness. I wasn't able to change that, although testing the kernel parameters acpi_backlight=vendor and acpi_osi='!Windows 2012'. That tip (bottom of the page) given in the arch wiki had no effect OR didn't even let me boot when I tried to adjust the BusID to the output of lspci...
So I got another solution, these selfmade scripts:
/usr/local/bin/darker
#!/bin/bash
CURR=`cat /sys/class/backlight/intel_backlight/brightness`
MIN=3
NEW=$(($CURR-50))
if [ $NEW -lt 5 ]
then
NEW=5
fi
echo $NEW > /sys/class/backlight/intel_backlight/brightness
and
/usr/local/bin/brighter
#!/bin/bash
CURR=`cat /sys/class/backlight/intel_backlight/brightness`
MAX=`cat /sys/class/backlight/intel_backlight/max_brightness`
NEW=$(($CURR+50))
if [ $NEW -gt $MAX ]
then
NEW=$MAX
fi
echo $NEW > /sys/class/backlight/intel_backlight/brightness
which work.
Assigning these scripts to keys also works with "sudo darker" / "sudo brighter" and adding them via visudo.
The only thing missing to make it perfect, is the combination:
Using the default brightness keys including the XFCE onscreen notification/popup binded to those scripts. (Just assigning to the brightness keys would make me lose the on screen notifiaction/popup...)
So how is that possible, has anyone an idea?
Last edited by Carl Karl (2014-10-14 15:21:14)

Answer 1

Thanks, that's quite good, except that multiple key-presses lead to multiple notification popups which is not sooo nice bad acceptable. (And as this is run by root, a sudo xfce4-notifyd-config is necessary to configure the notification.)
for reference:
/usr/local/bin/brighter
#!/bin/bash
CURR=`cat /sys/class/backlight/intel_backlight/brightness`
MAX=`cat /sys/class/backlight/intel_backlight/max_brightness`
NEW=$(($CURR+20))
if [ $NEW -gt $MAX ]
then
NEW=$MAX
fi
echo $NEW > /sys/class/backlight/intel_backlight/brightness
notify-send "Backlight $(($NEW*100/$MAX)) %"
/usr/local/bin/darker
#!/bin/bash
CURR=`cat /sys/class/backlight/intel_backlight/brightness`
MIN=3
MAX=`cat /sys/class/backlight/intel_backlight/max_brightness`
NEW=$(($CURR-20))
if [ $NEW -lt 5 ]
then
NEW=5
fi
echo $NEW > /sys/class/backlight/intel_backlight/brightness
notify-send "Backlight $(($NEW*100/$MAX)) %"
So any idea how to avoid these multiple notifications? notify-send --help wasn't helpful for me.