I'm responsible for maintaining an old VO2.8 application that uses the even older V3 DynaZip component for zipping and unzipping files. We've hit an issue where a couple of clients need to create zip files for backups that exceed 2Gb, and DynaZip won't handle it.
Does anyone know a simple solution to this, or are we going to have to change the zip component? Does FabZip handle files >2Gb? We need to keep the work required to an absolute minimum as all our efforts are in .Net these days, but we need to resolve the issue for the clients as well.
it's been a long time since my latest changes with FabZip , but as far as I remember the underground component is supporting files up to 4G and then you can also use the split-file capability.
But just to be sure, I will dust-off my VO28, check, and come back
PKZIP supported files up to 4Gb (2^32 bytes) (both contained files and the zip file) until version 8. After that zip64 supported very large files (2^64 bytes). 4Gb is also the maximum file size in FAT32. Lots of zip-implementations only supports file sizes up to 2Gb, like Windows XP.
I've just tried using the Demo app of FabZip :
after few corrections due to mix between DWORD/LONG that was wrong for bigger file, I have been able to create a 2.8Gb file, with some ISO inside (like Ubuntu, Suse-Leaf,.. ), so I can confirm that FabZip is able to support >2Gb files
It is the zip format that has limits! If I remember correctly, it should be something like 4 GB for a single zipped file and 8 GB for the total file or vice versa. In the Internet the correct limits can be retrieved. It can happen that a program creates zip files exceeding these limits without errors and instead it has created zip files that are corrupt and cannot be opened anymore. There are different programs like PKZIPC that have extended the limits but have created a new format that cannot be read by standard zip functions. So better change the format if you need bigger sizes. Having multi media files or complex Office documents the installations have grown quickly.
We're edging towards a complete replacement with FabZip. Two questions:
1. Looking on your website, I found an old news item about FabZip from 2006 where you say that it's stuck with a 2Gb limit due to the underlying components, and that there's no solution. Checking the latest download, I see the Zipdll.dll and Unzdll.dll files are dated 2004... so presumably are still the same ones as when you decided 2Gb was the limit. But of course you've just tested it now with >2Gb. Not sure what to make of that
2. We need progress bars with such big time consuming processes - does FabZip support this?
I can send you all the AEFs I've used in order to proceed to test after your message :
I had to make some corrections in order to support 2Gb limit : I was using WORD/LONG at sensible offset calculation places, and it was crashing my own code, not the Unzip/Zip DLLs
The lib comes in 2 flavors : GUI or NoGui
In both versions, you can register to some events,that will give you progress info; The GUI sample app is using that with progress Bars, so you can have a look.
I'm not sure to have your email adress : Can you send me a mail to fabrice at xsharp.eu ?
I will then send you all the files.