Re: when does ssh return?

Hello,

Any process should "wait()" for all of its children to exit or the children
will become a zombie process when they exit. This isn't a good thing.

See wait() 2, and fork() 2 for more information.

Regards,

-- 
Jason Muskat  | GCUX - de VE3TSJ
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TechDude
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> From: David Richardson <dgr24@drexel.edu>
> Date: Fri, 05 May 2006 16:03:39 -0400
> To: <secureshell@securityfocus.com>
> Subject: when does ssh return?
>
> I've looked through ssh man page and FAQ and tried a google search, but
> can't seem to figure out how to use ssh to start a command on a remote
> machine, have ssh exit immediately, and still have the command running
> on the remote machine.
>
> When I do
>
> [popcorn][~]$ time ssh dave@popcorn "sleep 10&"
>
> real    0m10.216s
> user    0m0.060s
> sys     0m0.000s
>
> ssh waits for the sleep to finish.  Does anyone either understand why
> ssh is waiting for sleep to finish or how to make it not do it?
>
> I've tried
>
>      ssh dave@popcorn "run_and_return sleep 10"
>
> where run_and_return is the bash script:
>
>      #!/bin/bash
>      ?@&
>
> and a similar thing with a perl script that forks.  I even tried having
> the perl script fork, have its child fork, and then the grandchild
> execute the command.
>
> But ssh keeps sticking around...
>
> Thanks for any help,
> Dave
>
> p.s. I'm using
>
> [popcorn][~]$ ssh -V
> OpenSSH_3.5p1, SSH protocols 1.5/2.0, OpenSSL 0x0090701f
>
> on
>
> [popcorn][~]$ uname -a
> Linux popcorn 2.4.20-6 #1 Thu Feb 27 10:01:19 EST 2003 i686 athlon i386
> GNU/Linux
>
> with Fedora Core 2 installed.