[net.sources] Versions of compression/archive programs

rbj@icst-cmr (Root Boy Jim) (08/27/86)

	> Version history has always been something I've liked....
	> Here's the best I can do from a largely ms-dos background.:
	> 
	> sq/usq:
	> lbr:
	> arc:
	> uuencode/uudecode:
	> compress:
	> tar:
	> binhex:
	> packit:
	> 
	> That's all I could come up with.
	> 
	> Edward Vielmetti
	
	An article this informative should get a public thanks, so here
	it is.  Now, if I only knew how to get ahold of all the
	authors/publishers Edward referred to...

	By the way, upon rereading it, I realized that my original
	posting might have been misleading.  The purpose of uuencode is
	not to compress, but to make unprintable/unsendable files
	sendable, I believe.  Thus, compressed/squeezed ASCII needs to
	be uuencoded.  But this increases the size of the file,
	negating much of the benefit of the compression.  This is all
	over and above the mashing that usq/arc and compress do against
	each other, again negating the beneficial effects of the
	squeezing.  I just don't think it makes sense to do it.

More garbage in net.sources. Sorry about that. Anyway, uuencode expands
the character count by a ratio of 4/3, then adds a header line.
To be effective, you must attain a compression rate of at least 25%.
This is easily done on text, and on binarys which have to be encoded
anyway, anything is welcome, and 25-30% is not uncommon. As an aside,
there is a program called `btoa' which comes with compress that
expands 4 chars to 5, and replaces 4 nulls with only one char.

	-- 
	bc				Bill Crews @ NetCor Data International
	
	..!{seismo,gatech,ihnp4}!ut-sally!cyb-eng!bc  (512) 835-2937
	
	(Root Boy) Jim Cottrell		<rbj@icst-cmr.arpa>
	LBJ, LBJ, how many JOKES did you tell today??!