Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!sun-barr!decwrl!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Communications Toolbox questions
Message-ID: <9285@hoptoad.uucp>
Date: 14 Dec 89 06:18:54 GMT
References: <9125@hoptoad.uucp> <36869@apple.Apple.COM> <9188@hoptoad.uucp> <37028@apple.Apple.COM> <9223@hoptoad.uucp> <872@excelan.COM>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 61

In article <9223@hoptoad.uucp> tim@hoptoad.UUCP (Tim Maroney) writes:
>>While we're on the subject, can you briefly sketch how an FTP protocol
>>tool could be created under the Communications Toolbox?

In article <872@excelan.COM> brianb@plasma.UUCP (Brian Bulkowski) writes:
>Boy, wouldn't I like to know that too! What I'd like out of the CommTB
>is a generic file transfer method. For me, file transfer is broken into
>(at least) these parts:
>1) query list of host files.
>2) query list of local files.
>3) get host files.
>4) put local files.
>5) make directories in both file structures.
>6) move around in both file structures.
>7) Encode or decode various file formats (XMODEM, MacBinary, ... )
>
>I was hoping that that's what a file transfer tool would do all of these
>things independantly. Thus I could use my FTP interface (boy, do I like it)
>over LU6.2. Or FTAM. Or AFP.
>
>Is this possible? Reasonable?

It's a good idea, and I'm planning to do something similar.  There are
two ways to do it, using two levels of extension mechanism.  In either
case, you have to add code describing these or similar operations for
each shell program supporting these operations.  The best way to do it
is with a script language, because then power users who are not
programmers can add support for new shell programs.  The other way is
to allow code resources (XCMD style) to be added to the program; this
requires more expertise, but also gives more power and better speed.

Then these "shell program tools" would call the ordinary Comm. Toolbox
tools to do the low-level get and put operations.

The problem is, this is not something that it would be "nice" to have
with FTP; it's practically mandatory if FTP is to be usable by most
users.  The command set for FTP is hardly something you can expect
novice users to learn and to type in raw.  It seems like the only current
way to implement someting like this is to have a TELNET terminal tool to
the command port, then a file transfer tool that does TCP to the data
port.  The string to recognize an incoming file would be (let's see)
oh dear, there's no single numerical code indicating that a transfer
is about to start.  That's a problem.  How does the software know when
to start up the reception?  It seems as if "Receive File" will have to
be special cased for an FTP connection, violating protocol independence.

None of these problems are insoluble, but I would like some sign from
Apple that they have at least been considered.  I'm extremely disturbed
that TELNET and FTP tools were not shipped with the Toolbox "beta".
There are a lot of TELNET and FTP features which do not seem to be
supportable, such as the OS-independent control character options in
TELNET.  In many ways, it looks as if this software should be called
the "Modem Toolbox" instead; it certainly would not be possible to just
take a multi-modem terminal emulator, plunk some new tools into the
Communications folder, and have a TCP/IP terminal emulator.  I think
it's rather telling that no one has answered my FTP question.
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com

"Superhero stories could best be described as entertainment that externalizes
 childhood power fantasies." -- Timothy Fay on rec.arts.comics