libzip: libzip-discuss: Re: "Extra" data field on files

Thread

Thread Index

Message

From: Jono Spiro <jono%scribd.com@localhost>
To: libzip-discuss%nih.at@localhost
Subject: Re: "Extra" data field on files
Date: Thu, 10 Jun 2010 17:04:44 -0700

I have a patch that adds a zip_{set,get}_file_extra() function. I'll push this to the maintainers separately.

- Jono


On Tue, Jun 8, 2010 at 10:05 PM, Jono Spiro <jono%scribd.com@localhost> wrote:
New to the group and libzip, but I've spent hours trying to answer this myself and have hit a wall:

Is there currently a way in libzip to write to the optional "extra" data field that is specified for a ZIP file header at offset 30+strlen(file name) (http://en.wikipedia.org/wiki/ZIP_(file_format)#File_headers)? I need to add an adler32 checksum here (DADA0400 followed by the checksum). I am streaming ZIP files into Flash and unzipping them as they download -- unfortunately the Flash player in the browser requires this checksum to be injected -- even if it's wrong.

Any help would be incredible!

Cheers,
Jono

---
PS: On http://nih.at/libzip/: You should update "You can subscribe to it by sending a mail with the subject "subscribe libzip-discuss" to minimalist at nih.at." to read "at giga.or.at" -- since the other address doesn't work.

Made by MHonArc.