I have a script that runs in the background every half an hour which syncs a users music folders to my media server using rsync and after sends a notfiy-send message to the desktop to tell me its worked without failing, (once I'm confident in its operation ill change to only notify on errors) what I would like to know is how to make notify send use an icon from the users current icon theme or a generic theme, I'm sure I read it can be done without specifying a full file path but now can't find out how.

Any ideas?