I also thought that having a program constantly running to change my desktop background was a little excessive.

So I wrote a little switcher in perl. I used perl because I wanted to make sure that the desktop actually switched each time (i.e., no direct repeats) and I felt that perl was better for this than a shell script.

I had to go the symbolic link route because Gnome requires DBUS_SESSION_BUS_ADDRESS to be set, it’s only set in the environment of your X session, and there was no (good) way to extract that via cron. Which is why you always see bg changers outside of cron.

The usage is pretty straight forward:

randombg.pl <directory>

Where <directory> is where your backgrounds are located.

Note 1: <directory> defaults to ~/Pictures, so if that’s where you have your backgrounds then you don’t need to send a command line to it).

Note 2: this will create a symbolic link called background.jpg in your picture directory, so make sure that file doesn’t already exist.

I then set this up in cron:

0-59/15 * * * * ~/scripts/randombg.pl


That swaps out my background every 15 minutes.

You can download randombg.pl.gz here