Hello,
I need to extend my application to unzip .zipx files. This appears to be the latest and greatest zip compression from WinZip.
Does anyone know of a library that will do this?
Thanks
+2
A:
One thing I would suggest is looking here.
it seems they are open to developers.
Daniel A. White
2009-07-29 13:39:03
+7
A:
Alternatively, tell WinZip where they can stick their closed proprietary compression format.
Matt Howells
2009-07-29 13:39:32
+1 as i loled.
tim
2009-07-29 13:40:15
Except for the non-standard extension It doesn't sound too proprietary to me. Compression algorithms like bzip2 are specified by the Zip standard.
Joey
2009-07-29 13:52:44
and LZMA, and PPMd. But, not many tools and libraries support all these compression formats, and in particular Windows Explorer does not. So .zipx is tantamount to saying "you can open this only with WinZip." Not sure if 7zip opens zip files that use LZMA compression.
Cheeso
2009-07-30 04:35:43
While neither SharpZipLib nor DotNetZip have support listed, 7Zip 4.65 was able to open any zipx archive that I found online. Hopefully that helps somebody.
dariusz
2010-02-04 18:26:01
+2
A:
According to Wikipedia WinZip uses .zipx as extension for Zip archives that use compression methods newer than deflate. Deflate is perhaps the minimum standard of Zip which everyone can compress or extract but newer algorithms like bzip2, LZMA or PPMd+ are also defined by the standard.
As for libraries which are able to handle newer compression algorithms you may have luck with SharpZipLib which implements at least bzip2 compression. There is also DotNetZip but it seems to be a little low on newer features.
Joey
2009-07-29 13:51:59
(I wrote DotNetZip). I guess it would be possible to produce an LZMA and PPMd capability but never got a formal request. I looked at the LZMA SDK but my head spins when I see the code. Feasible, but it will take some effort.
Cheeso
2009-07-30 04:34:07
A:
As Johannes Rossel mentioned SharpZipLib is a decent compression library written in C# and has source code available. This library is used in various projects as well and seems to have decent support. The only negative aspect is that I don't think they currently support WinZip's new zipx format. In fact I haven't found any other application or library that currently supports this new format other than WinZip. If you need a library for their new format probably the first place to start checking is with the WinZip support department to see if they have a native library available that could be wrapped or some specifications on the new format. If this file format is a closed spec then unfortunately you may not have many options.
jpierson
2009-07-29 14:48:30
It's still the old format. It's just a kind of marker that the archive uses newer compression algorithms than deflate.
Joey
2009-07-30 01:08:33