GNOME2 - Running script with root privileges at login.

[divisionbyzero]

Hey, I have created a python daemon (a basic power management program) and one of the things it does is write integers (0-10) to /sys/class/backlight/..../brightness... so as to change the screen brightness. This file is owned by the root and I cannot change that.

In the python daemon, I call the short script 'change_brightness.py' that handles writing these integers to the above brightness file. When I call this script I call it with the sudo command. [ Popen('sudo', 'python', 'change_brightness.py') - no password required by the way ]

This works perfectly, and once I'm logged in, I can call change_brightness.py and it will change the brightness accordingly.
However, when I run my daemon while logging in to Gnome (using startup applications), for some reason the change_brightness.py script is not called successfully with root privileges. The daemon starts up and keeps running in the background, but it's useless because it can't call any of its scripts successfully as root.

[salahx]

Brightness can be controlled via xrandr, so you shouldn't need the daemon.

Otherwise, if that won't work, you could solve this the way many applications have: Rewrite your daemon a D-Bus service.