I've accidentally attached to a 2nd GNU screen session from within an existing screen session and cannot detach or issue commands to the inner screen. I remember figuring out how to do that before but completely forgot and would like to keep it as reference.
One way is to detach the inner screen by doing screen -dr from shell, but what is the key combination to do that from within screen itself?
Yeah, you're on your own with that. <esc> a d may work; the man page is ambiguous, since it says that a sends the escape character, then clarifies that what it means by that is ctrl-A. So it's a crapshoot.
Thanks, there we go, that's exactly what I remembered too and when I told it to my co-worker who was having this problem, he said it didn't work. Of course, now I found out he was pressing ctrl-a, ctrl-a, d, instead of ctrl-a, a, d. Voted and closed.