Re: what are .sdk archives?

[dempson@actrix.gen.nz (David Empson)]

<touchstone> wrote:

> On 2007-12-26 17:01:11 -0700, dempson@actrix.gen.nz (David Empson) said:
> 
> > Michael J. Mahon <mjmahon@aol.com> wrote:
> > 
> >> Michael Kent wrote:
> >>> To: touchstone
> >>>> 
> >>>> i give up!!
> >>> 
> >>>> thanks everyone for their input on this, but i simply cannot get an
> >>>> unforked file transfered from a mac.
> >>> 
> >>> If you have access to a IIgs -- perhaps through emulation -- ShrinkIt GS
> >>> can handle the .sdk archives directly, and it will handle forked files
> >>> just fine.  You could then re-archive the disk or files into a different
> >>> format if you have to.
> >> 
> >> And once you get UNFORKIT working (which is actually a pretty small
> >> Applesoft program), you can easily access everything else.
> >> 
> >> Have I mentioned how much I wish the Mac would not add forks to
> >> files that don't have them?  ;-)
> > 
> > It doesn't.  The only reason a Mac will add a resource fork to a file
> > which doesn't have one is if you do something like add a custom icon to
> > the file. It is perfectly OK to have a file on the Mac with a data fork
> > and a zero length resource fork.
> 
> the mac is not adding a macintosh resource fork.  although prodos is
> claiming that a forked file exists, while it may, it is not refering to
> the macintosh fork. the forked prodos archivew i was working with had
> resource forks of zero k, and would only add the fork if i asked the fork
> editor to add one.

The key issue is that ProDOS-8 doesn't support a file with the
"extended" storage type.

A standard ProDOS file (storage type of sapling, seedling or tree) has a
directory entry which points to a single data bock (sapling), single
index block (seedling), or second level index block (tree).

An extended ProDOS file (supported by GS/OS and the Mac) adds an
extended key block between the directory entry and file data. The
extended key block contains two partial directory entries to define the
data fork and resource fork of the file (either of which may be empty,
or a seedling, sapling or tree), plus it can store extended information
about the file, which is used for Mac-specific directory information.

Anything claiming that a file is "forked" on ProDOS-8 might be
misleading. It really means the file is extended, which might or might
not have a resource fork.

The extended storage type and extra block are sufficient to prevent
ProDOS-8 from doing anything useful with the file (short of third-party
utilities which do block-level access to the volume).

-- 
David Empson
dempson@actrix.gen.nz