Create a screen, launch a command in it and detach

Question

I'd like to do a one line bash command that automatically does this:

screen -S myserver 
python myserver.py  # inside the new screen
CTRL A, D (detach)

I think this won't work:

screen -S myserver && python myserver.py

because python myserver.py won't be started inside the screen.

Answer 1

You can detach right after starting a program inside of screen:

screen -dmS myserver python myserver.py

From screen's man page

-d -m Start screen in detached mode. This creates a new session but doesn't attach to it. This is useful for system startup scripts.

Answer 2

The answer from @Stefan M is good, but is not quite like running a command within the screen, because when the command ends, the whole screen will end. If you actually run a command within the screen, then when it quits, you'll be left with a shell.

You can retain that shell with this:

screen -s "/bin/bash" -dmS myserver; screen -S myserver -X stuff "python myserver.py\n"; 

This will first launch the screen, with a shell, and then send some commands into that shell to run. This will behave exactly as if you typed those commands into the screen yourself.

A more elaborate script is available here: https://unix.stackexchange.com/a/766301/598166