Screen sharing: who is using the hardware display?

I'm looking for a terminal command to find out which user is using the hardware display of system with screen sharing enabled. The built in OSX screen sharing client is smart enough to tell you who it is when you connect, at the point where it asks if you want the primary display or a virtual display.

Does anyone know of a way to get this information via command line, or some other means, rather than running the OSX lion connection client?

Paul

 

yep, thanks. It tells me who is logged in. But it does not say who is using the real hardware and who is virtual via screen sharing.