I have this screen process which has open my serial port:

$ sudo lsof | grep /dev/ttyS0

    screen    23520        root    6u      CHR               4,64         0t0       1421 /dev/ttyS0

$ cd /proc/23520

$ head -n 5 status

    Name:   screen

    State:  S (sleeping)

    Tgid:   23520

    Pid:    23520

$ screen -ls

    There is a screen on:

        21200.pts-1.porkypig    (07/10/2013 12:25:42 PM)    (Detached)

$ screen -r 21200.pts-1.porkypig

When I reattached to the screen session, to see exactly what it's doing. I see this long log of information. It seems like the result of "tail -f", that is, a continous log being output.

/proc/23520 $ cd cwd

 pwd

/proc/23520/cwd

ls -l

-rw-r--r--  1 root        root        2147 2013-10-07 17:55 minicom.log

When I switch into the directory (cwd) that this process was run from, I notice minicom.log, which makes me suspect the user ran something like "tail -f minicom.log".

I know that in linux we can use history to track back commands that were run. But how can I confirm the command was run to display what I am currently looking at in my screen session?