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diff content/GNUstep/new-zipper-release.md @ 98:1d9382b0329b
Specify the syntax on markdown blocks to avoid broken output that has class=err
author | Dirk Olmes <dirk@xanthippe.ping.de> |
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date | Thu, 19 Dec 2019 10:04:33 +0100 |
parents | 4cd9b65e10e4 |
children |
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--- a/content/GNUstep/new-zipper-release.md Thu Dec 19 09:31:57 2019 +0100 +++ b/content/GNUstep/new-zipper-release.md Thu Dec 19 10:04:33 2019 +0100 @@ -4,10 +4,12 @@ I had to debug Mule's build for the upcoming 1.4.1 release a bit, especially the packaging of the JCA distribution. I usually use Zipper to open archives, that's why I wrote it in the first place. It turns out that some file extensions are ambiguous, e.g. a file ending in .rar could either be a rar archive or a Java Resource ARchive which is effectively a zip file. Since the rar packager cannot handle zip files I picked up an idea I had in mind for a long time now: file types should not be determined by their extensions but the way the unix file command does it: by looking for certain patterns inside of a file. I implemented the most simple cases in Zipper now: Zip files begin with + :::shell { 'P', 'K', 0x003, 0x004 } and rar files begin with + :::shell { 'R', 'a', 'r', '!'} straight from the beginning of the file. When opening a file Zipper asks all registered Archive subclasses for their magic bytes and compares them to the first four bytes of the file. I think I will extend this mechanism a bit in the future so in the end all supported archives will be determined by a file's content and not by its file extension any more.