[Xitami] FTP problems

[Brian {Hamilton Kelly}]

In message <200112280919.WAA09230@pagoda.in.naos.co.nz>
   Ewen McNeill writes:
> In message <7DF4D412-FB6E-11D5-949F-0003933D8C18@mac.com>, Bruce Axtens writes:
> >On Friday, December 28, 2001, at 04:04  PM, Ewen McNeill wrote:
> >> Don't use FTP.  Use HTTP.  It's much cleaner.)
> >
> >Pardon my newbie-ness but, like, how?
> 

[snip some "why HTTP is superior to FTP" advocacy]

> FTP has no reliable way to return date/time meta information about
> files; each FTP client "guesses" this information from directory
> listings, after having guessed what the directory listing format is.
> HTTP specifically includes this information in its answer.  HTTP has a
> "get if modified" request; the equivilent in FTP involves getting a
> directory listing, guessing the format, guessing the details of the
> file, comparing it with what you have, and hoping for the best.
> 
> There's plenty more.  But basically FTP was designed by a bunch of grad
> students 20-something years ago making it up as they went along to solve
> a much more general problem than was really required, in an environment
> security and firewalls weren't an issue.  HTTP was designed more
> recently (about 10 years ago), and is much more firewall friendly.

Apart from the more-firewall-friendly aspect, I feel that you are being
more than a little unfair on both FTP and its implementors.
(Particularly in referring to Jon Postel as a "grad student".)

Might I remind you of the following (from RFC-1123, dated October 1989)?

         The File Transfer Protocol FTP is the primary Internet standard
         for file transfer.  The current specification is contained in
         RFC-959 [FTP:1].

         FTP uses separate simultaneous TCP connections for control and
         for data transfer.  The FTP protocol includes many features,
         some of which are not commonly implemented.  However, for every
         feature in FTP, there exists at least one implementation.  The
         minimum implementation defined in RFC-959 was too small, so a
         somewhat larger minimum implementation is defined here.

         Internet users have been unnecessarily burdened for years by
         deficient FTP implementations.  Protocol implementors have
         suffered from the erroneous opinion that implementing FTP ought
         to be a small and trivial task.  This is wrong, because FTP has
         a user interface, because it has to deal (correctly) with the
         whole variety of communication and operating system errors that
         may occur, and because it has to handle the great diversity of
         real file systems in the world.

It was RFC-1123 (aka STD-3), incidentally, which first standardized
certain extensions to FTP, such as PASV.  There are also more recent RFCs
which amplify 959, including at least three which have the status of
"proposed standard".

-- 
Brian {Hamilton Kelly}                                          bhk@dsl.co.uk
    "We have gone from a world of concentrated knowledge and wisdom to one of
    distributed ignorance.  And we know and understand less while being incr-
    easingly capable."              Prof. Peter Cochrane, formerly of BT Labs