[8.0p1] After the remote ssh command execution, the session does not terminate until an active disconnect

[Hong Cho]

Just so you know making a change like this works for our tool.

ssh user at example.com "ourtool > /var/tmp/output 2>/dev/null &"

No "nohup" needed.

Thanks for all the help.

Hong.

On Wed, Aug 21, 2019 at 8:01 AM Damien Miller <djm at mindrot.org> wrote:

> On Tue, 20 Aug 2019, Jakub Jelen wrote:
>
> > On Tue, 2019-08-20 at 16:00 +0900, Hong Cho wrote:
> > > Thank you for the reply.
> > >
> > > I changed the remote command to a generic example because in our
> > > case, we
> > > are using an internal binary that I didn't want to make public. I
> > > thought
> > > it wouldn't matter, but apparently, it does. I am sorry I can't share
> > > more
> > > about this tool.
> > >
> > > BTW, our environment is based on FreeBSD, not on Linux. In our case,
> > > because "isatty" is set to 0, it never closes.
> >
> > It never closes, because the `tail -f` never exists and never closes
> > the stdout and stderr that are connected to ssh channels.
> >
> > Yes, this is a difference from the previous openssh versions, but I
> > think this is a correct behavior. Previously, the ssh ran the command
> > in background and closed its IO.
>
> AFAIK that's not the case - the behaviour change only affects programs
> that output to stderr.
>
> OpenSSH 7.2 doesn't exit "tail -f &" either, because it doesn't
> write anything to stderr.
>
> -d
>