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From: karn@FALINE.BELLCORE.COM (Phil R. Karn)
Newsgroups: comp.protocols.tcp-ip
Subject: FTP advisory messages
Message-ID: <8709141836.AA24625@faline.bellcore.com>
Date: Mon, 14-Sep-87 14:36:43 EDT
Article-I.D.: faline.8709141836.AA24625
Posted: Mon Sep 14 14:36:43 1987
Date-Received: Tue, 15-Sep-87 06:45:50 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 16

A lot of new FTP users (and some veteran ones, too) get bitten by
forgetting to say "type image" before sending a binary file.  You get no
warning when you do this; you don't discover your mistake until you're
done and find that the file is corrupted. I would like to add an
advisory message to my own FTP server to warn the user when he/she does
this. The FTP client should just display this message to the user but
otherwise ignore it, relying on the user to abort the transfer. But how
should I do this?

I seem to remember that there are reply messages of the "0XX" class that
would do what I want, but I can't find it mentioned anywhere in the
specs.

Comments?

Phil