zipping/unzipping library?

[Allin Cottrell <cottrell wfu edu>]

Before I embark on this I'd like to find out if something of the 
sort already exists, or if someone else is already working in this 
area.  Also, perhaps, how much interest there might be in this 
project.

What I'm thinking would be useful is a library, with the portability 
level of glib, offering the functionality of creating and extracting 
files from zip archives.  I envisage it using both glib and zlib, 
and offering a basic API with these elements:

* A function to create a zip file, given a target filename, a list 
of files to archive, and a compression level.

* A function to retrieve a list of file attributes from a zip 
archive.

* A function to extract all, or a selected list of, files from a zip 
archive.

This functionality is already present in the Infozip packages, zip 
and unzip.  But although these packages contain some gestures toward 
offering a library API, this has not been taken very far.  And 
although the infozip programs work very nicely, the code is not 
pretty (for one thing, it's choked with #ifdefs for every ancient 
architecture known to man).

The zlib API itself is fine; but it's quite low level, and it leaves 
the application programmer to do much of the grunt work involved in 
creating or reading a multi-file zipfile.

One further comment: I can imagine the question, why bother with the 
zipfile format when gzipped tar is better?  My response is that for 
better or worse the PKzip format has become a de facto standard, now 
enshrined in the ODF specs, and I'd like for my app to be able to 
read and write ODF files.

--
Allin Cottrell
Department of Economics
Wake Forest University, NC