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I have been trying to send commands to a running gnu screen session (4.00.03) in opensolaris, but cannot get it to run any commands through any combination of screen -X

Ok, I start a screen session with screen -S test, and then tried to with screen -r -X "date"to just show me the date, when I would reconnect to it. But neither an error message nor output in the screen happened. I tried with so many combinations, that I can't even remember.

Any hints on how to accomplish it?

The reason why I am doing this is, because I have a program, which does not come as a daemon, and I wish to start it in a screen session, so I can later on see what is going on.

2
  • 1
    it seems, as if this "command" that they are talking about in the man pages is meant for a screen command, like settings for the screen session itself. Rather than sending commands for the shell, which is opened in the screen session. So, anyone an idea of how to make it happen with a bash script??
    – aXon
    Mar 5, 2010 at 11:29
  • @Axon: Yes, -X sends screen commands, not shell commands, but screen has a command 'screen' which can open new screen windows.
    – Roger Pate
    Mar 5, 2010 at 20:43

4 Answers 4

19

Actually it's quite simple. You can use the following:

screen -S sessionname -X stuff 'command'`echo -ne '\015'`

echo -ne '\015' emulates pressing the Enter key.

NOTE: that 'stuff' is a screen command. http://www.gnu.org/software/screen/manual/screen.html#Stuff

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    Could you please specify what "stuff" represents? Is that a name...or command...or other parameters?
    – Cerin
    Aug 24, 2012 at 21:37
  • It works in fact, but I wouldn't say it's simply anyhow ;) This is something like passing keypressed events and passing newline to the screen. Isn't there just normal screen execute command...?
    – ducin
    Feb 8, 2013 at 12:55
  • @Cecin: stuff is a screen command to 'stuff' a string into stdin
    – konrad
    Sep 17, 2013 at 11:51
  • This is very good, but for some reason it doesn't work with "screen -RdS sessionname -X stuff 'ls -l'echo -ne '\015'", why?
    – e271p314
    Feb 12, 2014 at 10:21
  • this doesn't work for me... does not emulate enter key... Jun 10, 2018 at 5:32
6

Sounds like you want:

$ screen -S test -d -m -c /dev/null -- sh -c 'date; exec $SHELL'

-S test: name this session
-d -m: start screen detached
-c /dev/null: ignore ~/.screenrc (provide a different file or drop this option,
  as needed)
--: end of screen options
sh -c 'date; exec $SHELL': command for screen to run, note that if this command
  was just 'date' then screen would exit immediately.  if you don't want to exit
  screen after your command exits, then you might use:
    $ screen -S test -d -m -c /dev/null -- your command here

Or maybe you just want dtach.

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  • Running this results in nothing. No success or error messages, but screen -list shows no sessions are open.
    – Cerin
    Aug 24, 2012 at 21:44
  • This answer worked for me. The key was the -- to end the screen options.
    – Plazgoth
    Jul 29, 2016 at 17:05
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screen -S <session_name> -X screen [-t <title>] <shell_command> [<args>]

Open a new window (with title title) in an existing session named session_name, and execute shell_command (with optional arguments args)

1

Like some of the comments on here, I was also unable to get this command to work at first, on Ubuntu Server 22.04. Here's what actually worked for me:

screen -S <sessionName> -p 0 -X stuff 'command^M'

The -p 0 was what did it to select the first window, despite the stuff command claiming that it operates on "the current window", and the ^M was a nicer alternative form of the echo -ne '\015'.

From: https://raymii.org/s/snippets/Sending_commands_or_input_to_a_screen_session.html

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