Bash Script to Set Your Backlight Brightness
For whatever reason, one day after putting my laptop to sleep (a ThinkPad T530 running Debian 9.1) xrandr became disconnected. After I rebooted, xrandr was working properly again, but tools like xrandr and xbacklight weren't able to set my backlight's brightness... so I wrote this script.
I haven't managed to get it working with my function keys yet.
Minor update: xrandr works fine with backlight, but it is only able to change the software brightness... this script is still necessary to change the hardware backlight levels.
I think there's a problem with the Gnome 3 Shell Backlight/Brightness plugin, hence why my fn keys don't work.