Terminating SSH session executed by bash script

Question

I have a script I can run locally to remotely start a server:

#!/bin/bash ssh [email protected] <<EOF   nohup /path/to/run.sh & EOF echo 'done' 

After running nohup, it hangs. I have to hit ctrl-c to exit the script.

I've tried adding an explicit exit at the end of the here doc and using "-t" argument for ssh. Neither works. How do I make this script exit immediately?

EDIT: The client is OSX 10.6, server is Ubuntu.

Answer 1

I think the problem is that nohup can't redirect output when you come in from ssh, it only redirects to nohup.out when it thinks it's connected to a terminal, and I the stdin override you have will prevent that, even with -t.

A workaround might be to redirect the output yourself, then the ssh client can disconnect - it's not waiting for the stream to close. Something like:

nohup /path/to/run.sh > run.log & 

(This worked for me in a simple test connecting to an Ubuntu server from an OS X client.)

Answer 2

The problem might be that ...

... ssh is respecting the POSIX standard when not closing the session  if a process is still attached to the tty. 

Therefore a solution might be to detach the stdin of the nohup command from the tty:

nohup /path/to/run.sh </dev/null & 

See: SSH Hangs On Exit When Using nohup

Yet another approach might be to use ssh -t -t to force pseudo-tty allocation even if stdin isn't a terminal.

man ssh | less -Ip 'multiple -t'  ssh -t -t [email protected] <<EOF   nohup /path/to/run.sh & EOF 

See: BASH spawn subshell for SSH and continue with program flow