sshd hangs on logout -- is this a bug?

[Nicolas Williams]

This is normal behaviour for RSH and is natural behaviour anyways.

For example: when should "ssh somehost somecommand" exit? When
'somecommand' exits? or when it *and* all it's children have exited? And
what if you were starting a daemon?

But daemons *detach* from their current TTY, and *that* is key here. If
'somecommand' in the above example leaves background children processes
when it exist and those children still have the ssh tty open then they
may want to read/write from/to that tty -- and the ssh user might well
expect to be able to interact with such background children processes.

Thus this is normal behaviour.

Just remember, when you don't want hanging rsh/ssh's do this:

ssh -n somehost somecommand \> /dev/null 2\>\&1

It might be nice to have an option like -n but for stdout/stderr to
avoid the need for quoting (and to be more portable, after all, that "\>
/dev/null 2\>\&1" bit is Bourne Shell specific and can't be guaranteed
to work with all ssh daemons (think Windows).

Nico


On Wed, Sep 05, 2001 at 04:57:51PM -0700, Adam McKenna wrote:
> In the changelog, there is an entry:
> 
> 20001129
>  - (djm) Back out all the serverloop.c hacks. sshd will now hang again
>    if there are background children with open fds.
> 
> Does this mean that this is regarded as expected (and correct) behavior, that
> should not change in the future, or does it mean that this behavior is a
> known problem that someone will eventually fix?
> 
> --Adam
> 
> -- 
> Adam McKenna <adam at flounder.net>   | GPG: 17A4 11F7 5E7E C2E7 08AA
> http://flounder.net/publickey.html |      38B0 05D0 8BF7 2C6D 110A


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