Subject: Re: AppleDouble/Resource Forks....
From: Tom Watson (tsw@johana.com)
Date: Tue Aug 22 2000 - 06:54:27 EDT
On Tue, 22 Aug 2000 05:12:41 -0400 (EDT), netatalk-admins@umich.edu wrote:
> I was thinking about the resource fork situation on the Mac, and the
> apparent need for AppleDouble directories on netatalk - or is there?
>
<<<deletia>>>
>
> Thus, you'd have:
>
> +--------+-----------------+---------------------+
> <| header | xx data fork xx | ** resource fork ** |>
> +--------+-----------------+---------------------+
What you have here is called (TaDa) AppleSingle format!!
>
<<<deletia>>>
>
> Of course, I'm sure I overlooked something - so, what are the drawbacks to
> this suggestion?
The thing is that other operating system(s) use the data fork of the file
as their only structure. They desire to have the name associated with just
the data fork and handle the data there. They don't really need the
information in the resource fork. So, when they access the file they need
to fudge their way down the file using the header, and unless the underlying
operating system does it automatically (none do) they can't use the file
in the "combined" (AppleSingle) form. The same applies in the reverse
direction. A PeeCee writing a text file won't have the proper headers to
be read on the Apple Side. OOOPS.
Even Apple when writing (or modifying) PC format floppies (and I think
things like Zip Disks) uses a method similar to AppleDouble in storing
resource fork data. Format a DOS compatable floppy, then plunk it
into a DOS box and use a utility that will show all the "hidden" files.
There you will find the resource fork data.
>
> Harry
Of course, if one desires to keep things consistant, the AppleDouble part
of the file (having finder information, and resource fork data) could
include the inode number of the original file. If the two don't jive
due to modification or other such stuff, the Double part could be deleted.
In any event the AppleDouble part of the file is VERY necessary, in its
form.
-- Tom Watson Generic short signature tsw@johana.com (I'm at home now)
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