On Thursday 27 June 2002 09:38 am, Karl Ramberg wrote:

> Is this stuff hard to add to the squeak zipper so we don't have to
> use propritary tools ?

Well, you just add the proper records to the ZipArchiveMember's 
cdExtraField and/or localExtraField until it works with your favorite 
unzip utility. These have a size and an ID followed by ID-specific 
bytes.

Here's the support you'd need to add such fields:

ZipArchiveMember

addLocalExtraField: string
    localExtraField := localExtraField, string.

addCentralDirectoryExtraField: string
    cdExtraField := cdExtraField, string

But first, you have to answer these questions:

1) What do you want to do with:
* finder attributes
* data/resource forks
* macos filename

2) Which Mac zip program(s) do you want to be compatible with?
from http://haase-online.de/dirk/maczip/download/README.TXT

Zip Programs / Macintosh Extra-Data:
-----------------------------------------
A brief overview:
Currently, as far as I know, there are 6 Zip programs
available for the Macintosh platform. These programs build
(of course) different variants of Zip files:

	- Info-ZIP's first Port of Zip. Ported by Johnny Lee This
	Port is rather outdated and no longer supported (since
	1992). 68K only. Only minimal Mac-info is stored
	(Creator/Type, Finder attributes). Creator/Type: '????' /
	'????' Until year 1998, only UnZip 5.32 survived.

	- ZipIt by Tom Brown. This is Shareware and still supported
	I think. ZipIt has a nice GUI, but I found it can't handle
	large Zip files quite well. ZipIt compresses Macintosh files
	using the Mac Binary format. So, transferring files to other
	platforms is not so easy. Only minimal Mac-info is stored
	(Creator/Type, Finder attributes). Mac filenames are changed
	to a most compatible filename. Creator/Type: 'ZIP ' / 'ZIP '

	- PKZIP/mac v2.03/210d. This is Shareware. This Zip
	implementation for the Mac can be found on ASI's web site
	(http://www.asizip.com/products/products.htm).  The name of
	this program is misleading, it is NOT a product from PKWARE.
	 ASI's last release version is v2.03, and they also offer a
	newer beta version PKZIP/mac 210d. But even the Beta version
	is rather outdated (1995). Only minimal Mac-info is stored
	(Creator/Type, Finder attributes). The Zipfile format looks
	like incompatible to other platforms. (More details about
	the compatibility issue can be found in
	proginfo/3rdparty.bug!). Type: 'PKz1' Mac filenames are
	restored without any change.

	- Aladdin DropZip 1999, This is Shareware. Aladdin choosed
	the format of ZipIt. Therefore, it has the some drawbacks
	like ZipIt. Creator/Type: 'SITx' / 'ZIP '

	- SmartZip 1.0 1999 - by Marco Bambini Vampire Software.
	This is Shareware. SmartZip compresses Macintosh files using
	the Mac Binary. Therefore, it has the same drawbacks like
	ZipIt. Creator/Type: 'dZIP' / 'ZIP '

3) Why should we treat the Macintosh specially when we're not treating 
(for instance) Windows or Acorn specially?

-- 
Ned Konz
http://bike-nomad.com
GPG key ID: BEEA7EFE