scp not tolerant of extraneous shell messages

[Ben Lindstrom]

On Tue, 2 Jul 2002, Bryan Henderson wrote:

> >So sub-system servers are executed via a shell - the user's shell.
>
> OK, I see.  Not sure why I didn't before, unless I was blinded my
> fundamental belief that there's some difference between a subsystem
> and an ordinary command.  :-)
>
> So what is the essential difference between a subsystem and an ordinary
> command?  I see that the .sshrc doesn't get executed for a subsystem, and
> that sshd looks up the subsystem program by a special name rather than
> the client having to supply the filename.  Is that it?  It doesn't seem
> like enough to justify the extra concept.
>

As far as I can figure... SSH Corp got pissed at the 'scp: not found'
issue with people not being smart enough to handle pathing right.  So they
added a bit of bloat to do subsystems.  In which all you have to do is say
'Hey, I want service XYZ' and the server knows what your taking about
without depending on any path look up.

And thus Subsystems was born in the IETF draft.

- Ben