Prevent one user from graphical login (only login via ssh)

[DennyBeach]

I am running Ubuntu 11.10 desktop.

I have a special user account that runs a custom program as a default shell. That username needs to login via SSH to run the custom program which exits after the information is displayed. This part works great.

However, I do not want this username to be able to get a GDM desktop. I want for this username to only be able to login with SSH or to a command prompt.

Is there a way to do this while allowing other users to login normally to their GUI desktops?

Thank you.

[DennyBeach]

I did find one working method on my own:

"rm -r" the user's home folder, then create a new one and set its permissions to "d--x------". The user can successfully authenticate in the GDM login, but the desktop fails to load and brings back the login screen.

I'd like to think there is a cleaner way of doing this though.