Compatibility of large ZIP files

[Mathias Gerlach]

Hi

at vclzip.bizland.com/kpgbpro.htm you wrote that VCLZIP Pro uses the ZIP64-Format compatible with PK-Ware.

Now I've created a ZIP file with VCLZIP Pro (Size is 5.2 GB, compression level 0) and tried to open it with the latest version of well known ZIP utilities.

Most of them reported that the ZIP file is corrupt, e.g. UltimateZIP, WinRAR, WinAce, FilZip.

Only PowerArchiver seems to be fully compatible with ZIP files build with VCLZIP.

WinZIP 9.0 opens the ZIP file and some of the files can be extracted without problems. But extracting other files of the same ZIP file WinZIP reported: "This file is not in the standard ZIP 2.0 format...Version required to extract this file is 50. Compression method required to extract this file is 0."

In the WinZIP help file they write about a "64-bit Zip file extension".

Can you please tell me if there is a difference betwenn the ZIP64-Format in VCLZIP and the "64-bit Zip file extension" used by WinZIP?

What ZIP utilities are compatible with large ZIP files build by VCLZIP?

Thank you for your response,
Mathias

[Kevin]

VCLZip's Zip64 format should be compatable with PKZip. Testing during development was done against PKZip's zip utility.

However, WinZip did not support Zip64 until later. They do interpret the specs a little more stringently than even PKZip. I plan to make a modification in the next couple of weeks that should make VCLZip's implementation of Zip64 work with WinZip. I would guess it will make the others work too, assuming they all have implemented Zip64 capabilities.

[Mathias Gerlach]

admin said:

I would guess it will make the others work too, assuming they all have implemented Zip64 capabilities.

Have you done this modifications?

Are they part of the actual version 3.05?

[Kevin]

Yes, the changes are in 3.05.

Sorry I have had some account problems so I haven't been able to reply for awhile.

Kevin