The UNIX compress program uses a quite different implementation of the compression techniques used by zlib and gzip, so I'm not sure whether Compress::Zlib will be able to read .Z files.

Anyway, keep in mind that there are several different compression methods, and that the one that people usually refer to as 'zip' refers to PKZip, which is compatible with WinZip and InfoZip.

gzip and PKZip/WinZip/InfoZip use very different compression methods (just to say one difference, gzip can compress only one file, while the others can create compressed archives of several files), so compression and decompression programs will have to be paired. For example, gzip on one end and Compress::Zlib on the other.

-- 
        dakkar - Mobilis in mobile

Actually, I believe that gzip can uncompress .Z files but it cannot compress files into .Z format for licensing reasons or some such. So you may be good to go with that.

--
tbone1, YAPS (Yet Another Perl Schlub)
And remember, if he succeeds, so what.
- Chick McGee

Actually, zip and gzip use the same compression algorithm, deflate. Deflate is a variant of LZ77, and is used in other file formats (PNG, PDF). The file formats are different, with gzip compressing a single file, and zip making an archive with multiple files.