GNU Screen – Find Keys Bound by Bindkey in Screenrc

You can use the environment variable $STY to determine whether you're in a screen session and also what the name of the session is that you're inside.

Example

Initially we're sitting in a terminal window, not inside of a screen session.

$ echo $STY

$

Spin up a screen session:

$ screen -ls
There is a screen on:
    31543.tscrn (Detached)
1 Socket in /var/run/screen/S-saml.

Connect to it:

$ screen -r 31543.tscrn

Inside screen session:

$ echo $STY
31543.tscrn
$

Killing a session

With the name of the session you can kill it using screen.

$ screen -X -S tscrn kill

You can also use the number there too.

$ screen -X -S 31543 kill

Confirm that its been killed:

$ screen -ls
No Sockets found in /var/run/screen/S-saml.

I recently had to do this. On Stack Overflow I answered how to find the PID of the process running in screen. Once you have the PID you can use ps to get the command. Here is the contents of that answer with some additional content to address your situation:

You can get the PID of the screen sessions here like so:

$ screen -ls
There are screens on:
        1934.foo_Server         (01/25/15 15:26:01)     (Detached)
        1876.foo_Webserver      (01/25/15 15:25:37)     (Detached)
        1814.foo_Monitor        (01/25/15 15:25:13)     (Detached)
3 Sockets in /var/run/screen/S-ubuntu.

Let us suppose that you want the PID of the program running in Bash in the foo_Monitor screen session. Use the PID of the foo_Monitor screen session to get the PID of the bash session running in it by searching PPIDs (Parent PID) for the known PID:

$ ps -el | grep 1814 | grep bash
F S   UID   PID  PPID  C PRI  NI ADDR SZ WCHAN  TTY          TIME CMD
0 S  1000  1815  1814  0  80   0 -  5520 wait   pts/1    00:00:00 bash

Now get just the PID of the bash session:

$ ps -el | grep 1814 | grep bash | awk '{print $4}'
1815

Now we want the process with that PID. Just nest the commands, and this time use the -v flag on grep bash to get the process that is not bash:

$ echo $(ps -el | grep $(ps -el | grep 1814 | grep bash | awk '{print $4}') | grep -v bash | awk '{print $4}')
23869

We can use that PID to find the command (Look at the end of the second line):

$ ps u -p 23869
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
dotanco+ 18345 12.1 20.1 5258484 3307860 ?     Sl   Feb02 1147:09 /usr/lib/foo

Put it all together:

$ ps u -p $(ps -el | grep $(ps -el | grep SCREEN_SESSION_PID | grep bash | awk '{print $4}') | grep -v bash | awk '{print $4}')