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    - Unzip needs about 500 Kbytes of memory to unzip no matter
      how many files were compressed and expanded.

    - and finally one big macintosh-related problem:
      This port has one weak point: It's based on path names.
      As you may be already know: Path names are not unique on a Mac !
      The main reason is that an attempt to implement support exact
      saving of the MacOS specific internal file structures would
      require a throughout rewrite of major parts of shared code,
      probably sacrifying compatibility with other systems. I have
      no solution at the moment. The port will just warn you if you
      try zip from / to a volume which has a duplicate name.
      MacZip has problems to find the archive or the files. My
      (Big) recommendation: Name all your volumes with a unique
      name and MacZip will run without any problem.


Known Bugs:

    - crypted files in a zip archive are sometimes corrupt:
      I get an error message: invalid compressed data to inflate.
      Appearance of this error is purely be chance: I did a small
      test: Unzipping an archive containing 3589 files 56 files
      fails to unzip, so about 1.5%. Root cause is completely
      unclear to me :(

I strongly recommend to test your archive (e.g. unzip -t archive).





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      This port is rather outdated and no longer supported (since 1992).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 chose
      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 '

and finally:
    - Info-ZIP's latest Port of Zip. MacZip 1.0. Ported by me :-)
      It is supported (of course) and up to date. Full set of macintosh
      info is stored: Creator/Type, Finder attributes, Finder comments,
      MacOS 8.0 Folder settings, Icon/Folder Positions ...
      Mac filenames are restored without any change.
      Creator/Type: 'IZip' / 'ZIP '


Compatibility of my port; Extraction:
   - Archives from Info-ZIP's first port (by Johnny Lee) are
     still compatible.
   - Extraction of ZipIt archives is supported. This support
     is not complete: Filenames are correct but Directory names
     are sometimes mangled to a DOS compatible form. Segmented
     archives are not supported.
   - PKZiP/mac archive files are extracted without resource-forks
     and without any Finder info. I have no information about
     that zip format.

Compatibility of my port; Compression:
   - My port supports only the new Info-ZIP format (introduced
     with this port). Therefore archives created by MacZip 1.0
     (March 1999) must be extracted with this version or later
     releases of Info-ZIP's UnZip to restore the complete set of
     Macintosh attributes.

Note: This port is complete unrelated to the shareware ZipIt.
Even more, handling of special Macintosh attributes is
incompatible with ZipIt. This port (MacZip) may be used to
extract archives created by ZipIt, but make sure that you
get the result as you expected.



Macintosh Files; File Forks:
----------------------------

All Macintosh files comprise two forks, known as the data
fork and the resource fork.  Unlike the bytes stored in the
resource fork, the bytes in the data fork do not have to
exhibit any particular internal structure. The application
is responsible for interpreting the bytes in the data fork
in whatever manner is appropriate. The bytes in the resource
fork usually have a defined internal structure and contain
data object like menus, dialog boxes, icons and pictures.