set the screen brightness on startup

Question

On Ubuntu 14.04 I tried to dim the screen brightness to 50% on each system start in /etc/rc.local with the line

xbacklight -set 50%

right before the line exit 0

Why does this not work?

Is there a better solution?

Answer 1

You cannot call xbacklight in rc.local, because rc.local is not running in the X environment.

Add this command to your startup programs (gnome-session-properties):

xbacklight -set 50%

This will work

Answer 2

I use the following command to set my Surface Pro 3's brightness to 50%

xrandr --output eDP-1 --brightness 0.5

There are probably more direct ways to find your output names, but...

I installed and ran arandr. After positioning my displays how I wanted them I saved a layout (they'll show up in ~/.screenlayout/yourLayout.sh)

Then I modified that file to add the --brigtness flag, and configured the script to run at startup.