Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!ut-emx!churchh
From: churchh@ut-emx.uucp (Henry Churchyard)
Newsgroups: comp.compression
Subject: Re: Compressing more then one file in one compression-run ?
Summary: what about deleting file from archive then?
Message-ID: <49574@ut-emx.uucp>
Date: 28 May 91 17:19:09 GMT
References: <5655@mhres.mh.nl>
Organization: The University of Texas at Austin; Austin, Texas
Lines: 20


 In article <5655@mhres.mh.nl> hst@mh_co2.mh.nl (Klaas Hemstra) writes:
> I have an idea for all of you archive-builders.
> It would be nice if the archivers would be able to compress multiple files
> in one compression-run. This way it would be possible to obtain much higher
> compression ratios for certain sets of files.
> For example: If you have a lot of C sources in one directory and you want
> to compress it using PKZIP or ARC or ZOO, each file is compressed separately.
> If you make a tar archive (with unix tar) and then compress it with unix
> compress, the compression ratio will be better.

   But if you treated all the files in an archive as a single block
for the purpose of compression (rather than compressing each file in
an archive separately in isolation), then what would happen when you
deleted a file in the middle of an archive?  You would basically have
to uncompress the whole archive, delete the uncompressed file, and
then recompress everything else from scratch.  Not very efficient :-(

--
         --Henry Churchyard     churchh@emx.cc.utexas.edu