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From: clipper@csd.uwo.ca (Khun Yee Fung)
Newsgroups: comp.lang.perl
Subject: Re: Non-interactive ftp
Message-ID: <9105150345.AA29347@nomis.csd.uwo.ca>
Date: 15 May 91 03:45:22 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 52

Sorry if this does not have a lot to do with Perl.

>>>>> On 15 May 91 00:51:36 GMT, ziegast@eng.umd.edu (Eric W. Ziegast) said:

Eric> Do you suppose someone could create a program to sign on as ftp and
Eric> recursively go through some specified directory and transfer the
Eric> whole thing in one non-interactive command?

I have been thinking about this for a long time. All the solutions I
could think of are all basically hacks. The biggest problem is the
multitude of operating systems out there. All with different ways of
organizing directories and files.  If you assume only Unix systems,
then I have encountered three very different ftpds. One is the
pseudo-standard vanilla ftpd from Berkeley, one is like the ftpd of
the emsworth node of CMU, and the other one I forgot where I saw but
it has brief explanations on the same lines as the file and directory
entries.  You can of course write a program just to handle the
pseudo-standard ftpds.  There is already one such program, a bourne
shell script. I once had a copy. If that is all you want, find that
program.

Suppose the ftp protocol allows recursive transfering. There is still
a problem: some operating systems do not have a tree-like file system.
Too bad. If you define how the file system should look like in ftp,
think about millions of people who use ftp to transfer files to and
from different machines. They surely do not want to have a different
look to their directories and files when they log in as a user and log
in via ftp. So this solution is out as anonymous ftp is only one small
application of ftp. I personally think that the purposes of ftp and
anonymous ftp are very different.  The only solution is then to define
a protocol specifically for anonymous ftp. In this way, you can
include all the features (e.g. a line of description for each file or
directory) you want without worrying about other ftp applications.  I
somehow don't think the networking gods will be interested in this. It
is up to us, anonymous ftp users, to derive our own protocol and make
it the de facto standard, I guess.

I wrote a ftp client long ago and posted it here a few weeks ago. All
the basic stuff is there and you can surely modify it to recursively
get all the files in a directory tree.  This program allows you to
specify a command file even now. It will also let you change your mind
half way, specify a set of commands, get rid of the control terminal,
and send the whole thing to background.

Khun Yee

P.S. If you are interested, I have a draft anonymous ftp protocol I
wrote last year. Not many people cared.
--
     Name: Khun Yee Fung                        Email: clipper@csd.uwo.ca
        Paper mail: Department of Computer Science, Middlesex College
     The University of Western Ontario, London, Ontario, N6A 5B7  CANADA