ncompress - (Ver. 4.2.3) an improved file compressor

This is version 4.2 of (N)compress (an improved version of compress 4.1).

Compress is a fast, simple LZW file compressor.  Compress does not have
the highest compression rate, but it is one of the fastest programs to
compress data.  Compress is the defacto standard in the UNIX community
for compressing files.

'build' is a menu driven shell script for compiling, testing and
installing (N)compress. So to build and install (N)compress all you have to
do is run build.  Build will first test your system for default
settings. The current compile settings are stored in a special file
called compress.def.

For user with problems with build there is a default makefile included
called 'Makefile.def'. Also build is capable te generate a Makefile with
all options (option genmake).

(N)compress 4.2 has a special, fast compression hash algorithm.  This
algorithm uses more memory than the old hash table. If you don't want
the faster hash table algorithm set 'Memory free for compress' below
800000.

zcmp, zdiff, zmore were copied from version 4.1 without any changes.

The output of (N)compress 4.2 is fully compatible with that of compress 3.0.
In other words, the output of (N)compress 4.2 may be fed into uncompress 3.0 or
the output of compress 3.0 may be fed into uncompress 4.2.

The output of (N)compress 4.2 is not compatible with that of
compress 2.0.  However, compress 4.2 still accepts the output of
compress 2.0.  To generate output that is compatible with compress
2.0, use the undocumented "-C" flag.

Acknowleds

@@ -0,0 +1,20 @@
+Acknowledgments:
+
+(N)compress, Version 4.2
+
+Thanks to the previous authors whom I didn't contact, for making
+the program available originally.
+   Spencer W. Thomas   (decvax!harpo!utah-cs!utah-gr!thomas)
+   Jim McKie           (decvax!mcvax!jim)
+   Steve Davies        (decvax!vax135!petsd!peora!srd)
+   Ken Turkowski       (decvax!decwrl!turtlevax!ken)
+   James A. Woods      (decvax!ihnp4!ames!jaw)
+   Joe Orost           (decvax!vax135!petsd!joe)
+   Dave Mack           ([email protected])
+
+Also thanks to Frans Meulenbroeks, Jan Christiaan van Winkel,
+Peter van Hooft and the testers of comp.sources.reveiwed for testing
+this version on different platforms.
+
+-- 
+Peter Jannesen

Changes

@@ -1,3 +1,30 @@
+(N)compress cersion 4.2.2
+	Minor changes after the reviewes from comp.sources.reviewed
+	o Change the name to ncompress because of version problems.
+	o Start all scripts with ':'
+	o Added libary options to buidl script.
+	o Install zmore zcmp zdiff and manuals.
+	o Added patchlevel.h
+	o Updated README file. Created LZW.INFO
+	o a complete grammatical go-round
+	o Use utime.h if availble
+	o Change de default input/output buffer size to BUFSIZ. Because
+	  of performance problems with read a head on systems.
+	o Build generates a makefile.
+
+compress version 4.2.1 improvements
+	o Change the name to ncompress because of version problems.
+	o Completly rewrite of the compress and decompress functions.
+	  compress speedup 25-50% (user cpu time).
+	  decompress speedup 20-30% (user cpu time).
+    o Add special fast compress hash algorithm.
+	o Fix some minor things.
+	o use #include <utime.h> if availble.
+	o Cleanup the source code (I think so).
+	o Test if filename is not to long. This is done on runtime no fix length
+      size any more.
+	o Powerfull build script (test almost every thing).
+
 Modifications for version 4.1: 
 	o Added -r command line flag to allow recursive compression/
 	  decompression of directory trees. As a side-effect, compress
@@ -15,13 +42,14 @@ Modifications for version 4.1:
 	o Removed atob/btoa/tarmail/untarmail - my versions are
 	  based on btoa 5.2 which is not compatible with the atob
 	  included with compress4.0.
+
 Compress version 4.0 improvements:
 	o compress() speedup (10-50%) by changing division hash to xor
 	o decompress() speedup (5-10%)
 	o Memory requirements reduced (3-30%)
 	o Stack requirements reduced to less than 4kb
 	o Removed 'Big+Fast' compress code (FBITS) because of compress speedup
-    	o Portability mods for Z8000 and PC/XT (but not zeus 3.2)
+	o Portability mods for Z8000 and PC/XT (but not zeus 3.2)
 	o Default to 'quiet' mode
 	o Unification of 'force' flags
 	o Manual page overhaul

LZW.INFO

@@ -0,0 +1,85 @@
+The following article from James A. Woods, one of the earlier
+authors of compress, explains its relationship to the Unisys
+patent on the LZW compression method:
+
+From uunet!zephyr.ens.tek.com!uw-beaver!mit-eddie!wuarchive!usc!ucsd!ucbvax!agate!riacs!jaw Wed Aug  1 15:06:59 EDT 1990
+Article: 1282 of gnu.misc.discuss
+Path: alembic!uunet!zephyr.ens.tek.com!uw-beaver!mit-eddie!wuarchive!usc!ucsd!ucbvax!agate!riacs!jaw
+From: [email protected] (James A. Woods)
+Newsgroups: gnu.misc.discuss
+Subject: Sperry patent #4,558,302 does *not* affect 'compress'
+Keywords: data compression, algorithm, patent
+Message-ID: <[email protected]>
+Date: 31 Jul 90 22:09:35 GMT
+Organization: RIACS, NASA Ames Research Center
+Lines: 69
+
+#  "The chief defect of Henry King
+    Was chewing little bits of string."
+
+        -- Hilaire Belloc, Cautionary Tales [1907]
+
+     As a co-author of 'compress' who has had contact with an attorney for
+Unisys (nee Sperry), I would like to relay a very basic admission from Unisys
+that noncommercial use of 'compress' is perfectly legal.  'Compress' is also
+commercially distributed by AT&T as part of Unix System 5 release 4,
+with no further restrictions placed upon the use of the binary, as far
+as I am aware.
+
+     From conversations with Professor Abraham Lempel and others, it 
+appears that neither AT&T, Sun Microsystems, Hewlett Packard, nor IBM
+are paying any sort of license fees to Unisys in conjunction with patent
+#4,558,302.  It may be true that some organizations are paying fees for
+data compression technology licensed from one or more of the many holders
+of compression patents, but this is all independent from 'compress'.
+
+     In particular, I received a letter at NASA dated October 1, 1987 from
+John B. Sowell of the Unisys law department, informing me for the first
+time that some form of LZW was patented.  I naturally expressed
+skepticism that an algorithm could be patented (a murky legal area
+which remains so), stated that 'compress' is not identical to LZW,
+and in fact was designed, developed, and distributed before the ink
+on the patent was dry.  Several telephone conversations later, Mr. Sowell
+intimated that they would *not* seek any fees from users of 'compress'
+but instead were signing licensees for hardware implementations of LZW.
+
+     So, regardless of what you believe about a shady legal area, if anyone
+from Unisys contacts you to extract tribute for the use of 'compress', please
+tell them that, first, it is not theirs to begin with, and, second, there is
+someone who will testify in court about the conversation above.
+It is not even clear if anyone can "own" 'compress', since original developer
+Spencer Thomas, myself, and others placed the code in the public domain
+long before the adoption of the Berne copyright convention.
+
+     In light of the events above, it seems that the Free Software
+Foundation is being unduly paranoid about the use of 'compress'.
+Now I can well believe that FSF is more likely to be a legal target
+than a behemoth like AT&T, but if they are simply redistributing
+untouched free software developed years ago in the public sector,
+I see no problem.
+
+     Aside:  I am investigating, possibly for a case history to be
+recycled to USENET, the particulars of data compression patents.
+I am aware of the following patents: IBM's Miller-Wegman LZ variant,
+those of Telcor and ACT [losing candidates for the British Telecom modem
+standard], James A. Storer's work on limited lookahead as explicated in his
+text "Data Compression (methods and theory)", Computer Science Press, 1988,
+and the various patents pending associated with the Fiala and Greene
+CACM article of April, 1989 on textual substitution methods.
+If you have any lore, send it this way.
+
+
+
+                    Sincerely,
+
+                    James A. Woods
+                    NASA Ames Research Center (RIACS)
+                    [email protected] (or ames!jaw)
+
+
+P.S.  The algorithm patent issue certainly is a "topic A" at the moment.
+One useful reference is the review article by Anthony and Colwell --
+"Litigating the Validity and Infringement of Software Patents" in
+Washington and Lee Law Review, volume 41, fall 1984.  I know Robert Colwell
+personally.  As a practicing patent attorney, he tells me that, at a minimum,
+use of an invention "for research purposes" is legitimate.

MANIFEST

@@ -0,0 +1,17 @@
+   File Name		Archive #	Description
+-----------------------------------------------------------
+ Acknowleds                 1	
+ Changes                    1	
+ Makefile.def				1
+ MANIFEST                   1	This shipping list
+ LZW.INFO					1
+ README                     1	
+ build                      1	
+ compress.1                 1	
+ compress42.c               1/2	
+ patchlevel.h				2
+ zcmp                       1	
+ zcmp.1                     1	
+ zdiff                      1	
+ zmore                      1	
+ zmore.1                    1	

Makefile.def

@@ -0,0 +1,51 @@
+# Makefile
+
+# C complier
+CC=cc
+
+# Install directory for binarys
+BINDIR=/usr/local/bin
+
+# Install directory for manual
+MANDIR=/usr/local/man/man1
+
+# compiler options:
+# options is a collection of:
+#
+#	-DDIRENT=1					Use dirent.h
+#	-DSYSDIR=1					Use sys/dir.h
+#	-DLSTAT=1					Use lstat for finding symlinks.
+#	-DUTIME_H=1					Use utime.h
+#	-DUSERMEM=<size>			Availble memory for compress (default 800k).
+#	-DREGISTERS=<nbr>			Number of registers (default 2).
+#	-DIBUFSIZ=<size>			Input buffer size (default BUFSIZ).
+#	-DOBUFSIZ=<size>			Output buffer size (default BUFSIZ)
+#	-DBYTEORDER=<order>			Byte order (default: unknown).
+#	-DNOALLIGN=1				Data word allignment (default: yes).
+#	-DDEF_ERRNO=1				Define error (not defined in errno.h).
+#	-DMAXSEG_64K=1 -BITS=16		Support segment processsor like 80286.
+#
+options= -DIRENT=1 -DUSERMEM=800000 -DREGISTERS=3  
+
+# libary options
+LBOPT=
+
+compress:	Makefile compress42.c patchlevel.h
+	$(CC) -o compress $(options) "-DCOMPILE_DATE=\"`date`\"" compress42.c $(LBOPT)
+
+install:	compress
+		[ -f /usr/local/bin/compress ] && 			{ rm -f /usr/local/bin/compress.old ; 	  		mv /usr/local/bin/compress /usr/local/bin/compress.old ; }
+		rm -f /usr/local/bin/uncompress /usr/local/bin/zcat
+		cp compress /usr/local/bin/compress
+		strip /usr/local/bin/compress
+		rm -f /usr/local/bin/uncompress
+		ln /usr/local/bin/compress /usr/local/bin/uncompress
+		rm -f  /usr/local/bin/zcat
+		ln -f /usr/local/bin/compress /usr/local/bin/zcat
+		cp zcmp zdiff zmore /usr/local/bin/.
+		chmod 0755 /usr/local/bin/compress /usr/local/bin/zcmp /usr/local/bin/zdiff                    /usr/local/bin/zmore
+		cp compress.1 zcmp.1 zmore.1 /usr/local/man/man1/.
+		chmod 0644 /usr/local/man/man1/compress.1 /usr/local/man/man1/zcmp.1 				   /usr/local/man/man1/zmore.1
+
+cleanup:
+		rm -f compress compress.def comp.log