Date: Fri, 4 Mar 1994 10:59:48 -800 (PDT)
From: Mitra <mitra@pandora.sf.ca.us>
Subject: Re: FTP URL mapping
To: John Curran <jcurran@nic.near.net>
In-Reply-To: <9403040144.aa05625@nic.near.net>
Message-Id: <Pine.3.89.9403041005.A19683-0100000@pandora.sf.ca.us>
On Thu, 3 Mar 1994, John Curran wrote:
> I believe in trying to interoperate with _almost_ everything.
> However, I'm certain that are not FTP servers _so_ broken that
> interoperability is not a worthwhile goal.
>
> ] If anyone believes this is simple, I suggest looking at the gopher->ftp
> ] gateway, which has to special case for about 10 different ftp
> ] implementations.
>
> Just offhand, how many of these implementations would work without any
> special handling if the access process was a two-step "change directory"
> then "retrieve file" sequence? I'm of course presuming that the two
> components were clearly identified in the FTP URL...
I dont know, what I do know is that the gopher->ftp gateway handles almost
of the cases properly. There are only a few sites, with obscure
implementations, or using obscure ftp features (like multi-line banners
without leading digits on each line), that break.
I think, what this means, is that the ftp url is non-optimal, but does
allow a clever client to retrieve from any ftp server. I also contend
that to handle multiple ftp server implementations, a client is going to
have to be clever anyway - either to follow a complicated URL, or to
figure out the site its talking to. The problem with a complicated URL is
that many times its going to be specified incorrectly. If we keep it
simple, its more likely to be correct, and we can put the smarts in the
clients, rather than in the users.
- Mitra