As if screen wasn’t cool enough to start with, here’s a little bonus to make your day a wee bit brighter: There’s an -x flag for screen, which the man page and screen’s own –help tips suggest you can use to attach to a screen session that’s not detached. “Multi-user mode,” is what is added in parenthesis.
It sounds trivial, but at the same time suggests an impending train wreck. The idea of more than one person using a screen session brings to mind words like “race condition” and “wheel war.” And besides, there’s only one keyboard on most computers, so who’s going to want to huddle up next to their friend, and play two sessions of Stone Soup at the same time?
Yes, in the conventional “one keyboard one user” sense, it doesn’t sound like fun. But try it this way: Get to machines networked, and allow one to access the other with something like ssh. This is the setup I usually have for a music system, which sits on the other side of the house next to the router, and connected to the stereo. See here.
Now start up screen on the host machine, and keep it running in an open terminal. Then connect remotely and attach to the same screen session with the -x flag. Chances are if you’re in a position to watch both the original session and the remote session at the same time, you can do cool things and both screens will update together.