cottrell@NBS-VMS.ARPA (COTTRELL, JAMES) (02/28/86)
/* > TO WHOM IT MAY CONCERN > ---------------------- Hey, that's me! > > I am in need of a packing algorithm which works better than the > PACK Utility of UNIX. I have also looked at COMPRESS ( developed > at University of Utah ). COMPRESS works great if distinct number > of input bytes is small. But if the distinct input bytes reach > 256 ( binary data ), PACK works better than COMPRESS. With PACK > I am getting a saving of 20-25%. If anybody has an algorithm > that would do better in packing "load modules", I would like to > know about it. > > THNX...........Padam > > Name: Padam Maheshwari > Phone: (201) 580-4552 > Organization: AT&T Bell Labs > Address: 3ND15 > 184 Liberty Corner Rd > Warren, NJ 07060-0908 > NET Mail Address: ihnp4!pierce!pkm I just ran `compressdir -v' on (a *copy* of!) /bin. Here are the results, sorted by compression ratio. We run 4.2 BSD. Of course, Doug Gwyn would rather compress /bin/csh by 100% :-). The average compresion (ignoring true/false) seems to be 33.6%. I got my copy of compress via FTP off seismo, Version 4.0 7/30/85. Thanks guys! 1 ./false: Compression: -57.14% -- file unchanged 2 ./true: Compression: -57.14% -- file unchanged 3 ./vi: Compression: 25.01% -- replaced with ./vi.Z 4 ./passwd: Compression: 25.66% -- replaced with ./passwd.Z 5 ./ps: Compression: 26.21% -- replaced with ./ps.Z 6 ./grep: Compression: 26.75% -- replaced with ./grep.Z 7 ./make: Compression: 26.86% -- replaced with ./make.Z 8 ./rmail: Compression: 26.93% -- replaced with ./rmail.Z 9 ./diff: Compression: 27.38% -- replaced with ./diff.Z 10 ./sed: Compression: 27.79% -- replaced with ./sed.Z 11 ./cc: Compression: 27.84% -- replaced with ./cc.Z 12 ./ls: Compression: 27.89% -- replaced with ./ls.Z 13 ./login: Compression: 27.93% -- replaced with ./login.Z 14 ./csh: Compression: 28.05% -- replaced with ./csh.Z 15 ./pr: Compression: 28.30% -- replaced with ./pr.Z 16 ./tp: Compression: 28.66% -- replaced with ./tp.Z 17 ./chgrp: Compression: 28.77% -- replaced with ./chgrp.Z 18 ./mail: Compression: 28.94% -- replaced with ./mail.Z 19 ./cmp: Compression: 29.18% -- replaced with ./cmp.Z 20 ./tar: Compression: 29.21% -- replaced with ./tar.Z 21 ./adb: Compression: 29.43% -- replaced with ./adb.Z 22 ./mt: Compression: 29.63% -- replaced with ./mt.Z 23 ./as: Compression: 30.08% -- replaced with ./as.Z 24 ./dd: Compression: 30.18% -- replaced with ./dd.Z 25 ./mv: Compression: 30.20% -- replaced with ./mv.Z 26 ./write: Compression: 30.64% -- replaced with ./write.Z 27 ./sh: Compression: 30.68% -- replaced with ./sh.Z 28 ./time: Compression: 30.88% -- replaced with ./time.Z 29 ./ld: Compression: 31.10% -- replaced with ./ld.Z 30 ./cp: Compression: 31.55% -- replaced with ./cp.Z 31 ./ar: Compression: 31.62% -- replaced with ./ar.Z 32 ./hostid: Compression: 31.80% -- replaced with ./hostid.Z 33 ./od: Compression: 32.69% -- replaced with ./od.Z 34 ./expr: Compression: 32.86% -- replaced with ./expr.Z 35 ./du: Compression: 32.93% -- replaced with ./du.Z 36 ./su: Compression: 33.06% -- replaced with ./su.Z 37 ./rm: Compression: 33.34% -- replaced with ./rm.Z 38 ./cat: Compression: 33.50% -- replaced with ./cat.Z 39 ./date: Compression: 33.67% -- replaced with ./date.Z 40 ./stty: Compression: 33.96% -- replaced with ./stty.Z 41 ./nm: Compression: 34.52% -- replaced with ./nm.Z 42 ./size: Compression: 34.77% -- replaced with ./size.Z 43 ./wall: Compression: 35.02% -- replaced with ./wall.Z 44 ./ed: Compression: 35.07% -- replaced with ./ed.Z 45 ./mkdir: Compression: 35.20% -- replaced with ./mkdir.Z 46 ./rmdir: Compression: 35.27% -- replaced with ./rmdir.Z 47 ./pwd: Compression: 35.32% -- replaced with ./pwd.Z 48 ./hostname: Compression: 35.33% -- replaced with ./hostname.Z 49 ./awk: Compression: 35.36% -- replaced with ./awk.Z 50 ./kill: Compression: 36.04% -- replaced with ./kill.Z 51 ./ln: Compression: 36.13% -- replaced with ./ln.Z 52 ./who: Compression: 36.18% -- replaced with ./who.Z 53 ./df: Compression: 36.49% -- replaced with ./df.Z 54 ./chmod: Compression: 37.36% -- replaced with ./chmod.Z 55 ./strip: Compression: 37.94% -- replaced with ./strip.Z 56 ./pagesize: Compression: 39.24% -- replaced with ./pagesize.Z 57 ./nice: Compression: 44.86% -- replaced with ./nice.Z 58 ./test: Compression: 50.61% -- replaced with ./test.Z 59 ./tee: Compression: 58.47% -- replaced with ./tee.Z 60 ./echo: Compression: 59.47% -- replaced with ./echo.Z 61 ./sync: Compression: 63.30% -- replaced with ./sync.Z jim cottrell@nbs */ ------