fluxbox keys

I am using fluxbox as my primary window manager on both my laptop and home desktop. If you want a non distractive environment to work with, I strongly suggest to take a look.


On the laptop, I had a problem to configure the backlight. It was always on 100%, fixed without the ability to change it. If you run on battery, then you need to lower the brightness of your display.

After Linux kernel v3.16, things got a lot easier and better for newest models of laptops that had problems with the backlight and brightness.

You can find a lot of blog/site & wiki pages that suggest to append something of the below to your grub menu entry:


or something similar.


Note: On Dell XPS13 laptops a firmware bug exists when disabling legacy boot or switching through UEFI & legacy. That can break the backlight support and the result is a blank screen. This is a stupid manufacture error of Dell cause they used a different firmware module for backlight that can send different acpi events!

For me that’s irrelevant now. I am using UEFI and Linux kernel v4.0.5 and I have disabled legacy boot from my laptop a long time ago.
My grub menu doesnt have any of the above settings.


Ok, so now it’s time to explain how you can use fluxbox keys to control the brightness on your laptop.

Open a terminal and type:


With this program you can capture the keycode of the keys your are pressing.

I want to use the same keys that I would normally use for adjusting the display brightness on my laptop.
So on my machine, FN+F4 returns 232 and FN+F5 233.

Edit your ~/.fluxbox/startup file to add the below lines:

exec xmodmap -e "keycode 232 = F14 " &
exec xmodmap -e "keycode 233 = F15 " &

somewhere before

exec fluxbox

With the above commands, you are telling xorg to map the keycodes to a new key (even if that key doesnt exist on our keyboard). From now on, fluxbox will recognize FN+F4 (keycode 232) as F14 and FN+F5 (keycode 233) as F15.

At this point, if you have not already installed xorg-xbacklight, do it now.

The final step is to map our new keys to specific commands. Edit your ~/.fluxbox/keys so that you can add the below:

None F14 : ExecCommand xbacklight -dec 5
None F15 : ExecCommand xbacklight -inc 5

and restart your fluxbox !

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