I'm using Debian squeeze with Gnome Desktop for all my users. I have a group of machines to set up so that all users should use xpdf as a default viewer (rather than evince). I want this set up to be done by command line (even better, using puppet). I know about xpg-mime command, but the man page says that the default command should not be used as root. I could manually tweek the /etc/gnome/defaults.list files, but I'm looking for a single command I could run to perform the setting without an editor interaction. Any idea ?