Starting a background screen session from ssh.

Question

I would like to shoot a command to server to be run say forever! under "screen session" using ssh.

so I am using something like

ssh -t root@server screen -S myinf "python infinit1.py &"

where infinit1.py is the script. The problem the "python infinit1.py" doesn't go in a background and neither a screen called "myinf" is created.

I appreciate your hints.

`nohup` is your friend. It will keep the command running even after ssh session closes. — Jim G., Jul 16 '13 at 19:38
Thanks, it would be great to help me out to integrate screen session as well :) — user702846, Jul 16 '13 at 20:19

score 1 · Answer 1 · answered Jul 16 '13 at 19:34

do this

 ssh -t root@server "nohup bash -c '( ( /usr/bin/python infinit1.py &> /dev/null ) & )'"

this is because the tty that opened need to close and thus cannot keep the command running. to see the output, change /dev/null to an actual file name.

i have not tried to use remote screen so I omitted that. you may be able to get it to work but maybe the syntax is off a little bit.

score 1 · Accepted Answer · answered Jul 16 '13 at 21:36

1

This is because screen as invoked by you requires a pty to function. You will need to start screen in detached mode:

ssh root@server screen -d -m -S myinf python infinit1.py

answered Jul 16 '13 at 21:36

Dennis Kaarsemaker

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it work; may I ask why when I replace "python infinit1.py" with a simple "ls" command it does not work ? – user702846 Jul 17 '13 at 05:04
oh, it does work, but ls will terminate quickly, taking screen with it. You're likely to be too slow to ever see the session :) – Dennis Kaarsemaker Jul 17 '13 at 05:54
can I specify a pending time or something similar to avoid the quick termination ?! thank you. – user702846 Jul 22 '13 at 22:19

Rik Schneider · Answer 3 · 2013-07-16T23:26:51.597

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You don't need the quotes or the ampersand. Use the -d -m options to start screen in a detached mode instead. Take a look at the man page for more infomation.

A working example command line is:

ssh $host screen -S myinf -d -m tail -F /var/log/dmesg

edited Jul 16 '13 at 23:26

answered Jul 16 '13 at 21:39

Rik Schneider

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sudo for what !? I don't have sudo access ! – user702846 Jul 16 '13 at 23:01
It isn't important for the discussion. I used sudo to read a log file since I don't have infinit1.py on my test host. The important part is that everything after the options is considered a command line to run inside the screen session. – Rik Schneider Jul 16 '13 at 23:25

Starting a background screen session from ssh.

3 Answers3