Re: killing `ssh <host> <cmd>' does not kill <cmd> on <host>

[Petar Bogdanovic <petar%smokva.net@localhost>]

On Tue, Dec 09, 2008 at 10:19:14AM -0500, matthew sporleder wrote:
> On Tue, Dec 9, 2008 at 9:53 AM, Petar Bogdanovic <petar%smokva.net@localhost> 
> wrote:
> > Hi,
> >
> > when I run a `never ending' command like:
> >
> >   ssh host tail -f /var/log/maillog.0
> >
> > CTRL-C-ing ssh after tail has reached the end of maillog.0 does not kill
> > tail. If tail however suddenly would start to generate output again, it
> > would die immediately.
> >
> > This is not that much of a problem if the process just sleeps and does
> > nothing but there are certain cases where a running script soon will eat
> > too much memory if not killed immediately.
> >
> > Here's how `ps aux' on <host> looks like after killing the ssh client:
> >
> >   petar    9401  0.0  0.7  228   876 ?       Is    3:14PM 0:00.00 ksh -c ksh
> >   petar   15882  0.0  0.4   44   556 ?       I     3:14PM 0:00.00 tail -f 
> > /var/log/maillog.0
> >
> >
> > Is this desired behaviour? If not, how could one avoid it?
> >
> 
> Use ssh -t when doing tail -f so that ssh creates a tty and ends a
> command when it stops executing.
> 
> With -t:
> $ ps auxwww|grep [t]ail
> msporled 3556  0.0  0.4   32   492 ttyp3 S+   10:16AM 0:00.03 tail -f
> /var/log/messages
> msporled 4714  0.0  0.6  220   788 ttyp3 Ss+  10:16AM 0:00.03 ksh -c
> tail -f /var/log/messages
> 
> (notice ttyp3)
> 
> Without -t:
> $ ps auxwww|grep [t]ail
> msporled 5243  0.0  0.6  220   788 ?     Ss   10:17AM 0:00.03 ksh -c
> tail -f /var/log/messages
> msporled 5265  0.0  0.4   32   492 ?     S    10:17AM 0:00.05 tail -f
> /var/log/messages
> 
> (running in the background?)

That will do it, thanks!

Is there a way to force `-t' on all users? I just checked man
sshd_config but no luck..