Sending ctrl-c to specific screen session

Question

I am designing a script to launch a process inside a named screen session.

as_user "screen -p 0 -S **$command** -X eval 'stuff \"wine LFS.exe /cfg=**$command**.cfg\"\015'"

So bash myscript.sh start test will create a screen named test and run the test.cfg with the software.

Now I want my script to access the specific screen session and do a CTRL+C to stop the running process so i can kill the screen session.

Something like this:

as_user "screen -p 0 -S **$command** **... kill the process with ctrl-c...**"
as_user "screen -p 0 -S **$command** -X eval 'stuff \"exit\"\015'"

Nosology

Answer 1

I don't quite understand you but to send ctrl-c to a window in a screen session:

screen -S session_name -X at window_number stuff $'\003'
# or
screen -S session_name -X -p window_number stuff $'\003'

If you want to send something to all the windows, use # (needs to be quoted) as the window_number.

UPDATE:

Screen's stuff command also supports the use of ^X (or ^x) to represent CTRL-X so the following command can also be used to send CTRL-C.

# Here '^C' is two chars, '^' and 'C'
screen -S session_name -X at window_number stuff '^C'

Laster

Could not get at to work, but this worked for me for the active window only, which might be useful for someone: screen -S session_name -X stuff $'\003' – Coneflower

screen -S session_name -X at "#" stuff $'\003' with screen -S session_name -X quit works perfect for me. I am able to kill any screen session now. Thank you. – Cyclostyle

Awesome, this was exactly what I was looking for! Do you have more information the $'\003' encoding? Can I assume Ctrl+A would be 001, Ctrl+B would be 002 etc? Also, is there a way to send cursor up, down, left, and right keys? – Praedial

for ctrl chars see en.wikipedia.org/wiki/… – Laster

Oh and now that I'm wondering, since you mentioned screen also supports ^C. How do I type a literal ^ character? – Praedial

in the answer, for ^C, the ^ is the caret char. it's not the control char. – Laster

to send cursor up/down/left/right, you can first get the control sequence with tput. e.g. to get cursor up you can tput cuu1. details can be found in terminfo(5). – Laster

Thanks! screen -S session_name -X at window_number stuff '^C' works great on CentOS 7. – Swink