Re: Tramp and ssh control path

[Michael Albinus <michael.albinus@gmx.de>]

Suvayu Ali <fatkasuvayu+linux@gmail.com> writes:

> Hello Michael,

Hi,

> Extremely sorry about the late response; I set it to respond later in
> the day and forgot!

No problem.

>> Yes, Tramp uses its own one. This is necessary, because Tramp cannot
>> trust in an opened Master ssh connection opened outside Emacs. And OTOH,
>> you won't be blocked in your ssh sessions outside due to a closed Tramp
>> connection.
>
> I guess this means I cannot share my tramp connection with my terminal
> session outside of Emacs.

Yes. I *could* add a custom option to define a matching ControlPath
template. But I fear that there might be cases that the master session
is closed outside Emacs, and Tramp ceases to work then. Hard to debug,
and not Tramp's business. Unless I'm urged to introduce this option I'd
like to avoid it.

Maybe I shall say something in the FAQ about.

> I tried this again on a remotehost where I can use ssh keys (no password
> prompts), there everything works as expected.  However repeating it for
> the host where I have to use a password, fails as I described earlier.

>> Could you rerun your test with tramp-verbose set to 10, and show the
>> result?
>
> Okay I tried it.  The log has too much non-anonymous information to
> clean up, so I am sending it off-list, I hope that is okay with you.

Reading the traces, it happens that there is no problem with the
ControlPath settings of Tramp and with the password recognition. Both
run fine.

You have a problem with the prompt on that host. It looks like

--8<---------------cut here---------------start------------->8---
^[]2;sali@lxplus443.cern.ch:~^G01:44|sali@lxplus443:^[[35;1m(998)0/44^[[0m^[[31;1m^[[0m^[[33;1m ~> ^[[0m
--8<---------------cut here---------------end--------------->8---

A lot of escape sequences, which might confuse Tramp. Please change your
settings on the remote host to avoid them (the Tramp manual gives you
some hints).

And even without the escape sequences, your prompt looks like

--8<---------------cut here---------------start------------->8---
sali@remotehost.domain.ch:~01:44|sali@remotehost:(998)0/44 ~>
--8<---------------cut here---------------end--------------->8---

This does not fit `tramp-shell-prompt-pattern', please use a compatible
prompt (or adapt `tramp-shell-prompt-pattern').

> Thanks a lot,

Best regards, Michael.