Versions of compression/archive programs
Root Boy Jim
rbj at icst-cmr
Wed Aug 27 13:14:25 AEST 1986
> 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 at icst-cmr.arpa>
LBJ, LBJ, how many JOKES did you tell today??!
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