CRUSH is a compression tool that can work with your existing archiver to dramatically reduce the size of archives created. In many instances CRUSH achieves an average 2:1 advantage over PKZip and 8:1 over uncompressed files. However CRUSH is neither slow nor inconvenient to use. The command-line syntax is essentially similar to
PKZip, but with many powerful extensions.
CRUSH is a command-line tool that uses your existing archiver
PKZip, ARJ, LHA, ZOO,
HA or UC to generate smaller archives than it could alone. With many applications this improvement may be less than 5%, but dramatic improvements of 10%-70% are much more
typical. A block test of 128 archives totalling 2349 wordprocessing files averaged a 47% improvement (100k ZIP reduced to 53k CRUSH!). CRUSH is ideally suited to users who regularly archive material or who just need to save disk
The principal behind CRUSH is not new, but is not exploited by common
archivers. It takes advantage of the fact that big files will generally compress better than small files, a property used by Unix users who follow the maxim "always tar before compress"
(joining files together before compressing). CRUSH will automatically do this for
you, generating a single file with an extension "CRU" that it compresses using your chosen archiver (default PKZip). Extraction of files is then very easy: UNCRUSH works in the same way as
CRUSH gets the most from this compression trick by taking it
one step further and intelligently ordering the files before joining them. It
does this by recognising file types, reading them where needed (to recognise 7
different compressed header types), and orders them accordingly. This yields a
very good default fast compression.