jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) (07/04/90)
I have been trying to archive to diskette a bunch of the uuencoded software that I have collected off of the net news, and I was surprised to find that PKZIP 1.10 gives a compression ratio of 0% on uuencoded files. This seems curious, since obviously uuencoding decreases the information density. Are there any archivers that do a better job on uuencoded files? I don't want to uudecode them right now, since a lot of them have non-dos compatible filenames (e.g. for Minix, etc). -- John Dudeck "I always ask them, How well do jdudeck@Polyslo.CalPoly.Edu you want it tested?" ESL: 62013975 Tel: 805-545-9549 -- D. Stearns
dmm0t@hudson.acc.Virginia.EDU (David M. Meyer) (07/04/90)
In article <26910564.5118@petunia.CalPoly.EDU> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: > > >I have been trying to archive to diskette a bunch of the uuencoded software >that I have collected off of the net news, and I was surprised to find that >PKZIP 1.10 gives a compression ratio of 0% on uuencoded files. This seems >curious, since obviously uuencoding decreases the information density. You must be kidding. I usually get 25-40% compression on uuencoded files. Are you using the "-ex" option, to get maximum compression? >Are there any archivers that do a better job on uuencoded files? You could try lharc, but I doubt it would be significantly better. -- David M. Meyer dmm0t@virginia.edu Department of Mechanical and Aerospace Engineering University of Virginia Charlottesville, Virginia (804) 924-7926
ergo@netcom.UUCP (Isaac Rabinovitch) (07/04/90)
In <26910564.5118@petunia.CalPoly.EDU> jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: >I have been trying to archive to diskette a bunch of the uuencoded software >that I have collected off of the net news, and I was surprised to find that >PKZIP 1.10 gives a compression ratio of 0% on uuencoded files. This seems >curious, since obviously uuencoding decreases the information density. A wild guess: your files were compressed before they were uuencoded. Since a compressed file has relatively uniform infodensity, so will its uuencoded version. Don't some compression algorithms choke if you give them data with uniform consistency? They need un-subltle redundancy to squeeze out. -- ergo@netcom.uucp Isaac Rabinovitch atina!pyramid!apple!netcom!ergo Silicon Valley, CA uunet!mimsy!ames!claris!netcom!ergo "I hate quotations. Tell me what you know!" -- Ralph Waldo Emerson
jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) (07/11/90)
In an article dmm0t@hudson.acc.Virginia.EDU (David M. Meyer) wrote: >In an article jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes: >>I have been trying to archive to diskette a bunch of the uuencoded software >>that I have collected off of the net news, and I was surprised to find that >>PKZIP 1.10 gives a compression ratio of 0% on uuencoded files. This seems >>curious, since obviously uuencoding decreases the information density. > >You must be kidding. I usually get 25-40% compression on uuencoded >files. Are you using the "-ex" option, to get maximum compression? > Well, I looked back at the files that I was trying to zip, and discovered that they all were compressed (.Z) files before uuencoding. So I wouldn't really expect zip to be able to do too much compression on the .Z files. But still I would think that since uuencoding maps the binary data onto the printable ascii character set, it would be possible to recompress the data into 8-bit bytes taking full advantage of the size of a byte. I guess that it is expecting too much for it to reverse the effect of uuencoding. If that is what I want, I should use uudecode :^) The reason I didn't want to uudecode them under dos is that some files used unix filenames which would be lost. -- John Dudeck "I always ask them, How well do jdudeck@Polyslo.CalPoly.Edu you want it tested?" ESL: 62013975 Tel: 805-545-9549 -- D. Stearns