[Twisted-Python] Conch channel blocked

james bardin jbardin at bu.edu
Thu Feb 4 09:20:34 EST 2010

On Thu, Feb 4, 2010 at 9:01 AM,  <exarkun at twistedmatrix.com> wrote:
> I can't run your example code, since it's not a complete example.  That
> makes it harder to point out what's wrong with it.  However, one thing
> does strike me as wrong:
>>        while chunk:
>>            self.write(chunk)
>>            chunk = f.read(4096)
> This is a pattern you typically want to avoid, in Conch or anything else
> Twisted-based.  I don't know if SSHChannel is a consumer, but if not it
> should be, and you should be writing the file using a producer.  See:

It looked awkward, but the one example in the documentation was my
only starting point.

This is only a slightly modified version of that example, which writes
directly through the session channel, which makes sense in the
ssh-protocol, but apparently not here.

> http://twistedmatrix.com/documents/current/core/howto/producers.html

Thanks. I'll see if I can relate that into conch.

>>Does anyone know if any projects making good use of twisted.conch,
>>where I can see the source in action, and in depth?
> Mantissa uses Twisted Conch a bit:
> http://divmod.org/trac/browser/trunk/Mantissa/xmantissa/terminal.py
> But you won't find any code sending any exec requests there.

That's OK. any little bit helps.
I have a twisted service, and it needs to tunnel some information
through an ssh channel. Although this would take me a couple minutes
with another library, I feel I should be able to make use of what's
already built in to twisted, and not add another dependency.


More information about the Twisted-Python mailing list