Reattaching to an existing screen session

There are two levels of "listings" involved here. First, you have the "window listing" within an individual session, which is what ctrl-A A is for, and second there is a "session listing" which is what you have pasted in your question and what can also be viewed with screen -ls.

You can customize the session names with the -S parameter, otherwise it uses your hostname (teamviggy), for example:

$ screen

(ctrl-A d to detach)

$ screen -S myprogramrunningunderscreen

(ctrl-A d to detach)

$ screen -ls

There are screens on:
    4964.myprogramrunningunderscreen    (05/31/2013 09:42:29 PM)    (Detached)
    4874.pts-1.creeper  (05/31/2013 09:39:12 PM)    (Detached)
2 Sockets in /var/run/screen/S-paul.

As a bonus, you can use an unambiguous abbreviation of the name you pass to -S later to reconnect:

screen -r myprog

(I am reconnected to the myprogramrunningunderscreen session)

I had a case where screen -r failed to reattach. Adding the -d flag so it looked like this

screen -d -r

worked for me. It detached the previous screen and allowed me to reattach. See the Man Page for more information.

An easy way is to simply reconnect to an arbitrary screen with

screen -r

Then once you are running screen, you can get a list of all active screens by hitting Ctrl-A " (i.e. control-A followed by a double quote). Then you can just select the active screens one at a time and see what they are running. Naming the screens will, of course, make it easier to identify the right one.

Just my two cents