simmy@ocean.ocean.fsu.edu (Simmule Turner) (07/31/89)
#! /bin/sh
# This is a shell archive, meaning:
# 1. Remove everything above the #! /bin/sh line.
# 2. Save the resulting text in a file.
# 3. Execute the file with /bin/sh (not csh) to create the files:
# Readme
# compress.c
# compress.hlp
# This archive created: Sun Jul 30 18:50:03 1989
export PATH; PATH=/bin:$PATH
if test -f 'Readme'
then
echo shar: will not over-write existing file "'Readme'"
else
cat << \SHAR_EOF > 'Readme'
For compilation the equivalent of the Kreider c-library is needed.
This is for OS-9/6809.
Documentation provided by Tim Koonce.
Direct bug reports, flames, comments, questions to:
simmy@nu.cs.fsu.edu, or gatech!nu.cs.fsu.edu!simmy
SHAR_EOF
fi # end of overwriting check
if test -f 'compress.c'
then
echo shar: will not over-write existing file "'compress.c'"
else
cat << \SHAR_EOF > 'compress.c'
/*
* Modified to work under OS-9/6809 By Simmule Turner
* Last Modified 05/11/88 01:30:00
*
* Internet: simmy@nu.cs.fsu.edu
* Compuserve: 70651,67 Delpi: simmy
* Genie: simmy People Link: OKS619
*
*
* NOTE: due to a bug in level one compiler code of
* the following type needed modification.
*
* code |= *bp++ << r_off # Before correction
* code = code | (*bp++ << r_off) # After correction
*
* Wants:
* set file attributes see(copystat(xx,yy)).
*
*/
/* --------------Start Cut here for Plain Unix--------------- */
/*
* OS-9 Definitions - remove region to compile under unix.
*/
#define OS9
#define PBITS 12
#define BITS 12
#define HSIZE 5003
#define NO_UCHAR
#define short
/* ---------------End Cut here for Plain Unix---------------- */
/*
* a code_int must be able to hold 2**BITS values of type int, and also -1
*/
typedef int code_int;
typedef long int count_int;
#ifdef NO_UCHAR
typedef char char_type;
#else
typedef unsigned char char_type;
#endif /* UCHAR */
#ifdef OS9
char_type magic_header[] = "\037\235"; /* 1F 9D */
#else
char_type magic_header[] = { "\037\235" }; /* 1F 9D */
#endif
/* Defines for third byte of header */
#define BIT_MASK 0x1f
#define BLOCK_MASK 0x80
/* Masks 0x40 and 0x20 are free. I think 0x20 should mean that there is
a fourth header byte (for expansion).
*/
#define INIT_BITS 9 /* initial number of bits/code */
/*
* compress.c - File compression ala IEEE Computer, June 1984.
*
* Authors: 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)
*
* $Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $
* $Log: compress.c,v $
* Revision 4.0 85/07/30 12:50:00 joe
* Removed ferror() calls in output routine on every output except first.
* Prepared for release to the world.
*
* Revision 3.6 85/07/04 01:22:21 joe
* Remove much wasted storage by overlaying hash table with the tables
* used by decompress: tab_suffix[1<<BITS], stack[8000]. Updated USERMEM
* computations. Fixed dump_tab() DEBUG routine.
*
* Revision 3.5 85/06/30 20:47:21 jaw
* Change hash function to use exclusive-or. Rip out hash cache. These
* speedups render the megamemory version defunct, for now. Make decoder
* stack global. Parts of the RCS trunks 2.7, 2.6, and 2.1 no longer apply.
*
* Revision 3.4 85/06/27 12:00:00 ken
* Get rid of all floating-point calculations by doing all compression ratio
* calculations in fixed point.
*
* Revision 3.3 85/06/24 21:53:24 joe
* Incorporate portability suggestion for M_XENIX. Got rid of text on #else
* and #endif lines. Cleaned up #ifdefs for vax and interdata.
*
* Revision 3.2 85/06/06 21:53:24 jaw
* Incorporate portability suggestions for Z8000, IBM PC/XT from mailing list.
* Default to "quiet" output (no compression statistics).
*
* Revision 3.1 85/05/12 18:56:13 jaw
* Integrate decompress() stack speedups (from early pointer mods by McKie).
* Repair multi-file USERMEM gaffe. Unify 'force' flags to mimic semantics
* of SVR2 'pack'. Streamline block-compress table clear logic. Increase
* output byte count by magic number size.
*
* Revision 3.0 84/11/27 11:50:00 petsd!joe
* Set HSIZE depending on BITS. Set BITS depending on USERMEM. Unrolled
* loops in clear routines. Added "-C" flag for 2.0 compatibility. Used
* unsigned compares on Perkin-Elmer. Fixed foreground check.
*
* Revision 2.7 84/11/16 19:35:39 ames!jaw
* Cache common hash codes based on input statistics; this improves
* performance for low-density raster images. Pass on #ifdef bundle
* from Turkowski.
*
* Revision 2.6 84/11/05 19:18:21 ames!jaw
* Vary size of hash tables to reduce time for small files.
* Tune PDP-11 hash function.
*
* Revision 2.5 84/10/30 20:15:14 ames!jaw
* Junk chaining; replace with the simpler (and, on the VAX, faster)
* double hashing, discussed within. Make block compression standard.
*
* Revision 2.4 84/10/16 11:11:11 ames!jaw
* Introduce adaptive reset for block compression, to boost the rate
* another several percent. (See mailing list notes.)
*
* Revision 2.3 84/09/22 22:00:00 petsd!joe
* Implemented "-B" block compress. Implemented REVERSE sorting of tab_next.
* Bug fix for last bits. Changed fwrite to putchar loop everywhere.
*
* Revision 2.2 84/09/18 14:12:21 ames!jaw
* Fold in news changes, small machine typedef from thomas,
* #ifdef interdata from joe.
*
* Revision 2.1 84/09/10 12:34:56 ames!jaw
* Configured fast table lookup for 32-bit machines.
* This cuts user time in half for b <= FBITS, and is useful for news batching
* from VAX to PDP sites. Also sped up decompress() [fwrite->putc] and
* added signal catcher [plus beef in writeerr()] to delete effluvia.
*
* Revision 2.0 84/08/28 22:00:00 petsd!joe
* Add check for foreground before prompting user. Insert maxbits into
* compressed file. Force file being uncompressed to end with ".Z".
* Added "-c" flag and "zcat". Prepared for release.
*
* Revision 1.10 84/08/24 18:28:00 turtlevax!ken
* Will only compress regular files (no directories), added a magic number
* header (plus an undocumented -n flag to handle old files without headers),
* added -f flag to force overwriting of possibly existing destination file,
* otherwise the user is prompted for a response. Will tack on a .Z to a
* filename if it doesn't have one when decompressing. Will only replace
* file if it was compressed.
*
* Revision 1.9 84/08/16 17:28:00 turtlevax!ken
* Removed scanargs(), getopt(), added .Z extension and unlimited number of
* filenames to compress. Flags may be clustered (-Ddvb12) or separated
* (-D -d -v -b 12), or combination thereof. Modes and other status is
* copied with copystat(). -O bug for 4.2 seems to have disappeared with
* 1.8.
*
* Revision 1.8 84/08/09 23:15:00 joe
* Made it compatible with vax version, installed jim's fixes/enhancements
*
* Revision 1.6 84/08/01 22:08:00 joe
* Sped up algorithm significantly by sorting the compress chain.
*
* Revision 1.5 84/07/13 13:11:00 srd
* Added C version of vax asm routines. Changed structure to arrays to
* save much memory. Do unsigned compares where possible (faster on
* Perkin-Elmer)
*
* Revision 1.4 84/07/05 03:11:11 thomas
* Clean up the code a little and lint it. (Lint complains about all
* the regs used in the asm, but I'm not going to "fix" this.)
*
* Revision 1.3 84/07/05 02:06:54 thomas
* Minor fixes.
*
* Revision 1.2 84/07/05 00:27:27 thomas
* Add variable bit length output.
*
*/
static char
rcs_ident[] = "$Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $";
#include <stdio.h>
#include <ctype.h>
#include <signal.h>
#ifdef unix
#include <sys/types.h>
#include <sys/stat.h>
#else
#ifdef amiga
#include "types.h" /* Use our own version of types.h */
#include "stat.h" /* Use our own version of stat */
#endif
#endif
#ifdef datageneral
#include <math.h>
#include <sys/stat.h>
#include "types.h" /* Use our own version of types.h */
#endif
#ifndef min
#define min(a,b) ((a>b) ? b : a)
#endif
#define ARGVAL() (*++(*argv) || (--argc && *++argv))
int n_bits; /* number of bits/code */
int maxbits = BITS; /* user settable max # bits/code */
code_int maxcode; /* maximum code, given n_bits */
code_int maxmaxcode = 1 << BITS; /* should NEVER generate this code */
#ifdef COMPATIBLE /* But wrong! */
#define MAXCODE(n_bits) (1 << (n_bits) - 1)
#else
#define MAXCODE(n_bits) ((1 << (n_bits)) - 1)
#endif /* COMPATIBLE */
#ifdef XENIX_16
count_int htab0[8192];
count_int htab1[8192];
count_int htab2[8192];
count_int htab3[8192];
count_int htab4[8192];
count_int htab5[8192];
count_int htab6[8192];
count_int htab7[8192];
count_int htab8[HSIZE-65536];
count_int * htab[9] = {
htab0, htab1, htab2, htab3, htab4, htab5, htab6, htab7, htab8 };
#define htabof(i) (htab[(i) >> 13][(i) & 0x1fff])
unsigned short code0tab[16384];
unsigned short code1tab[16384];
unsigned short code2tab[16384];
unsigned short code3tab[16384];
unsigned short code4tab[16384];
unsigned short * codetab[5] = {
code0tab, code1tab, code2tab, code3tab, code4tab };
#define codetabof(i) (codetab[(i) >> 14][(i) & 0x3fff])
#else /* Normal machine */
count_int htab [HSIZE];
unsigned short codetab [HSIZE];
#define htabof(i) htab[i]
#define codetabof(i) codetab[i]
#endif /* XENIX_16 */
code_int hsize = HSIZE; /* for dynamic table sizing */
count_int fsize;
/*
* To save much memory, we overlay the table used by compress() with those
* used by decompress(). The tab_prefix table is the same size and type
* as the codetab. The tab_suffix table needs 2**BITS characters. We
* get this from the beginning of htab. The output stack uses the rest
* of htab, and contains characters. There is plenty of room for any
* possible stack (stack used to be 8000 characters).
*/
#define tab_prefixof(i) codetabof(i)
#ifdef XENIX_16
#define tab_suffixof(i) ((char_type *)htab[(i)>>15])[(i) & 0x7fff]
#define de_stack ((char_type *)(htab2))
#else /* Normal machine */
#define tab_suffixof(i) ((char_type *)(htab))[i]
#define de_stack ((char_type *)&tab_suffixof(1<<BITS))
#endif /* XENIX_16 */
code_int free_ent = 0; /* first unused entry */
int exit_stat = 0;
code_int getcode();
Usage() {
#ifdef DEBUG
fprintf(stderr,"Usage: compress [-dDVfc] [-b maxbits] [file ...]\n");
}
int debug = 0;
#else
fprintf(stderr,"Usage: compress [-dfvcV] [-b maxbits] [file ...]\n");
}
#endif /* DEBUG */
int nomagic = 0; /* Use a 3-byte magic number header, unless old file */
int zcat_flg = 0; /* Write output on stdout, suppress messages */
int quiet = 1; /* don't tell me about compression */
/*
* block compression parameters -- after all codes are used up,
* and compression rate changes, start over.
*/
int block_compress = BLOCK_MASK;
int clear_flg = 0;
long int ratio = 0;
#define CHECK_GAP 10000 /* ratio check interval */
count_int checkpoint = CHECK_GAP;
/*
* the next two codes should not be changed lightly, as they must not
* lie within the contiguous general code space.
*/
#define FIRST 257 /* first free entry */
#define CLEAR 256 /* table clear output code */
int force = 0;
char ofname [100];
#ifdef DEBUG
int verbose = 0;
#endif /* DEBUG */
int (*bgnd_flag)();
int do_decomp = 0;
/*****************************************************************
* TAG( main )
*
* Algorithm from "A Technique for High Performance Data Compression",
* Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19.
*
* Usage: compress [-dfvc] [-b bits] [file ...]
* Inputs:
* -d: If given, decompression is done instead.
*
* -c: Write output on stdout, don't remove original.
*
* -b: Parameter limits the max number of bits/code.
*
* -f: Forces output file to be generated, even if one already
* exists, and even if no space is saved by compressing.
* If -f is not used, the user will be prompted if stdin is
* a tty, otherwise, the output file will not be overwritten.
*
* -v: Write compression statistics
*
* file ...: Files to be compressed. If none specified, stdin
* is used.
* Outputs:
* file.Z: Compressed form of file with same mode, owner, and utimes
* or stdout (if stdin used as input)
*
* Assumptions:
* When filenames are given, replaces with the compressed version
* (.Z suffix) only if the file decreases in size.
* Algorithm:
* Modified Lempel-Ziv method (LZW). Basically finds common
* substrings and replaces them with a variable size code. This is
* deterministic, and can be done on the fly. Thus, the decompression
* procedure needs no input table, but tracks the way the table was built.
*/
main( argc, argv )
register int argc; char **argv;
{
int overwrite = 0; /* Do not overwrite unless given -f flag */
char tempname[100];
char **filelist, **fileptr;
char *cp, *rindex(), *malloc();
#ifndef OS9
struct stat statbuf;
#endif
extern onintr(), oops();
#ifndef OS9
----->unident the following region.<-----
#if (unix || (amiga && lattice))
if ( (bgnd_flag = signal ( SIGINT, SIG_IGN )) != SIG_IGN ) {
signal ( SIGINT, onintr );
#ifdef SIGSEGV
signal ( SIGSEGV, oops );
#endif
}
#endif
#else /* #ifndef OS9 */
if ( (bgnd_flag = signal ( SIGINT, SIG_IGN )) != SIG_IGN ) {
signal ( SIGINT, onintr );
}
#endif
#ifdef COMPATIBLE
nomagic = 1; /* Original didn't have a magic number */
#endif /* COMPATIBLE */
filelist = fileptr = (char **)(malloc(argc * sizeof(*argv)));
*filelist = NULL;
if((cp = rindex(argv[0], '/')) != 0) {
cp++;
} else {
cp = argv[0];
}
if(strcmp(cp, "uncompress") == 0) {
do_decomp = 1;
} else if(strcmp(cp, "zcat") == 0) {
do_decomp = 1;
zcat_flg = 1;
}
#ifdef BSD4_2
/* 4.2BSD dependent - take it out if not */
setlinebuf( stderr );
#endif /* BSD4_2 */
/* Argument Processing
* All flags are optional.
* -D => debug
* -V => print Version; debug verbose
* -d => do_decomp
* -v => unquiet
* -f => force overwrite of output file
* -n => no header: useful to uncompress old files
* -b maxbits => maxbits. If -b is specified, then maxbits MUST be
* given also.
* -c => cat all output to stdout
* -C => generate output compatible with compress 2.0.
* if a string is left, must be an input filename.
*/
for (argc--, argv++; argc > 0; argc--, argv++) {
if (**argv == '-') { /* A flag argument */
while (*++(*argv)) { /* Process all flags in this arg */
switch (**argv) {
#ifdef DEBUG
case 'D':
debug = 1;
break;
case 'V':
verbose = 1;
version();
break;
#else
case 'V':
version();
break;
#endif /* DEBUG */
case 'v':
quiet = 0;
break;
case 'd':
do_decomp = 1;
break;
case 'f':
case 'F':
overwrite = 1;
force = 1;
break;
case 'n':
nomagic = 1;
break;
case 'C':
block_compress = 0;
break;
case 'b':
if (!ARGVAL()) {
fprintf(stderr, "Missing maxbits\n");
Usage();
exit(1);
}
maxbits = atoi(*argv);
goto nextarg;
case 'c':
zcat_flg = 1;
break;
case 'q':
quiet = 1;
break;
default:
fprintf(stderr, "Unknown flag: '%c'; ", **argv);
Usage();
exit(1);
}
}
}
else { /* Input file name */
*fileptr++ = *argv; /* Build input file list */
*fileptr = NULL;
/* process nextarg; */
}
nextarg: continue;
}
if(maxbits < INIT_BITS) maxbits = INIT_BITS;
if (maxbits > BITS) maxbits = BITS;
maxmaxcode = 1 << maxbits;
if (*filelist != NULL) {
for (fileptr = filelist; *fileptr; fileptr++) {
exit_stat = 0;
if (do_decomp != 0) { /* DECOMPRESSION */
/* Check for .Z suffix */
if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") != 0) {
/* No .Z: tack one on */
strcpy(tempname, *fileptr);
strcat(tempname, ".Z");
*fileptr = tempname;
}
/* Open input file */
#ifdef datageneral
/* freopen() does not redirect stdin */
#endif
if ((freopen(*fileptr, "r", stdin)) == NULL) {
perror(*fileptr); continue;
}
/* Check the magic number */
if (nomagic == 0) {
if ((getchar() != (magic_header[0] & 0xFF))
|| (getchar() != (magic_header[1] & 0xFF))) {
fprintf(stderr, "%s: not in compressed format\n",
*fileptr);
continue;
}
maxbits = getchar(); /* set -b from file */
block_compress = maxbits & BLOCK_MASK;
maxbits &= BIT_MASK;
maxmaxcode = 1 << maxbits;
if(maxbits > BITS) {
fprintf(stderr,
"%s: compressed with %d bits, can only handle %d bits\n",
*fileptr, maxbits, BITS);
continue;
}
}
/* Generate output filename */
strcpy(ofname, *fileptr);
ofname[strlen(*fileptr) - 2] = '\0'; /* Strip off .Z */
} else { /* COMPRESSION */
if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") == 0) {
fprintf(stderr, "%s: already has .Z suffix -- no change\n",
*fileptr);
continue;
}
/* Open input file */
#ifdef datageneral
/* freopen() does not redirect stdin */
#endif
if ((freopen(*fileptr, "r", stdin)) == NULL) {
perror(*fileptr); continue;
}
#ifndef OS9
stat ( *fileptr, &statbuf );
fsize = (long) statbuf.st_size;
#endif
/*
* tune hash table size for small files -- ad hoc,
* but the sizes match earlier #defines, which
* serve as upper bounds on the number of output codes.
*/
hsize = HSIZE;
#ifndef OS9
if ( fsize < (1 << 12) )
hsize = min ( 5003, HSIZE );
else if ( fsize < (1 << 13) )
hsize = min ( 9001, HSIZE );
else if ( fsize < (1 << 14) )
hsize = min ( 18013, HSIZE );
else if ( fsize < (1 << 15) )
hsize = min ( 35023, HSIZE );
else if ( fsize < 47000 )
hsize = min ( 50021, HSIZE );
#endif
/* Generate output filename */
strcpy(ofname, *fileptr);
#ifndef BSD4_2 /* Short filenames */
if ((cp=rindex(ofname,'/')) != NULL) cp++;
else cp = ofname;
#ifdef OS9
if (strlen(cp) > 27) {
#else
if (strlen(cp) > 12) {
#endif
fprintf(stderr,"%s: filename too long to tack on .Z\n",cp);
continue;
}
#endif /* BSD4_2 Long filenames allowed */
strcat(ofname, ".Z");
}
/* Check for overwrite of existing file */
if (overwrite == 0 && zcat_flg == 0) {
#ifdef OS9
if (access(ofname,0) == 0) {
#else
if (stat(ofname, &statbuf) == 0) {
#endif
char response[2];
response[0] = 'n';
fprintf(stderr, "%s already exists;", ofname);
if (foreground()) {
fprintf(stderr, " do you wish to overwrite %s (y or n)? ",
ofname);
fflush(stderr);
read(2, response, 2);
while (response[1] != '\n') {
if (read(2, response+1, 1) < 0) { /* Ack! */
perror("stderr"); break;
}
}
}
if (response[0] != 'y') {
fprintf(stderr, "\tnot overwritten\n");
continue;
}
}
}
if(zcat_flg == 0) { /* Open output file */
#ifdef datageneral
/* freopen() does not redirect stdout */
#endif
if (freopen(ofname, "w", stdout) == NULL) {
perror(ofname);
continue;
}
if(!quiet)
fprintf(stderr, "%s: ", *fileptr);
}
/* Actually do the compression/decompression */
if (do_decomp == 0) compress();
#ifndef DEBUG
else decompress();
#else
else if (debug == 0) decompress();
else printcodes();
if (verbose) dump_tab();
#endif /* DEBUG */
if(zcat_flg == 0) {
copystat(*fileptr, ofname); /* Copy stats */
if((exit_stat == 1) || (!quiet))
putc('\n', stderr);
}
}
} else { /* Standard input */
if (do_decomp == 0) {
compress();
#ifdef DEBUG
if(verbose) dump_tab();
#endif /* DEBUG */
if(!quiet)
putc('\n', stderr);
} else {
/* Check the magic number */
if (nomagic == 0) {
if ((getchar()!=(magic_header[0] & 0xFF))
|| (getchar()!=(magic_header[1] & 0xFF))) {
fprintf(stderr, "stdin: not in compressed format\n");
exit(1);
}
maxbits = getchar(); /* set -b from file */
block_compress = maxbits & BLOCK_MASK;
maxbits &= BIT_MASK;
maxmaxcode = 1 << maxbits;
fsize = 100000; /* assume stdin large for USERMEM */
if(maxbits > BITS) {
fprintf(stderr,
"stdin: compressed with %d bits, can only handle %d bits\n",
maxbits, BITS);
exit(1);
}
}
#ifndef DEBUG
decompress();
#else
if (debug == 0) decompress();
else printcodes();
if (verbose) dump_tab();
#endif /* DEBUG */
}
}
exit(exit_stat);
}
static int offset;
long int in_count = 1; /* length of input */
long int bytes_out; /* length of compressed output */
long int out_count = 0; /* # of codes output (for debugging) */
/*
* compress stdin to stdout
*
* Algorithm: use open addressing double hashing (no chaining) on the
* prefix code / next character combination. We do a variant of Knuth's
* algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
* secondary probe. Here, the modular division first probe is gives way
* to a faster exclusive-or manipulation. Also do block compression with
* an adaptive reset, whereby the code table is cleared when the compression
* ratio decreases, but after the table fills. The variable-length output
* codes are re-sized at this point, and a special CLEAR code is generated
* for the decompressor. Late addition: construct the table according to
* file size for noticeable speed improvement on small files. Please direct
* questions about this implementation to ames!jaw.
*/
compress() {
register long fcode;
register code_int i = 0;
register int c;
register code_int ent;
#ifdef XENIX_16
register code_int disp;
#else /* Normal machine */
register int disp;
#endif
register code_int hsize_reg;
register int hshift;
#ifndef COMPATIBLE
if (nomagic == 0) {
putchar(magic_header[0]); putchar(magic_header[1]);
putchar((char)(maxbits | block_compress));
if(ferror(stdout))
writeerr();
}
#endif /* COMPATIBLE */
offset = 0;
bytes_out = 3; /* includes 3-byte header mojo */
out_count = 0;
clear_flg = 0;
ratio = 0;
in_count = 1;
checkpoint = CHECK_GAP;
maxcode = MAXCODE(n_bits = INIT_BITS);
free_ent = ((block_compress) ? FIRST : 256 );
ent = getchar ();
hshift = 0;
for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L )
hshift++;
hshift = 8 - hshift; /* set hash code range bound */
hsize_reg = hsize;
cl_hash( (count_int) hsize_reg); /* clear hash table */
#ifdef SIGNED_COMPARE_SLOW
while ( (c = getchar()) != (unsigned) EOF ) {
#else
while ( (c = getchar()) != EOF ) {
#endif
in_count++;
fcode = (long) (((long) c << maxbits) + ent);
i = ((c << hshift) ^ ent); /* xor hashing */
if ( htabof (i) == fcode ) {
ent = codetabof (i);
continue;
} else if ( (long)htabof (i) < 0 ) /* empty slot */
goto nomatch;
disp = hsize_reg - i; /* secondary hash (after G. Knott) */
if ( i == 0 )
disp = 1;
probe:
if ( (i -= disp) < 0 )
i += hsize_reg;
if ( htabof (i) == fcode ) {
ent = codetabof (i);
continue;
}
if ( (long)htabof (i) > 0 )
goto probe;
nomatch:
output ( (code_int) ent );
out_count++;
ent = c;
#ifdef SIGNED_COMPARE_SLOW
if ( (unsigned) free_ent < (unsigned) maxmaxcode) {
#else
if ( free_ent < maxmaxcode ) {
#endif
codetabof (i) = free_ent++; /* code -> hashtable */
htabof (i) = fcode;
}
else if ( (count_int)in_count >= checkpoint && block_compress )
cl_block ();
}
/*
* Put out the final code.
*/
output( (code_int)ent );
out_count++;
output( (code_int)-1 );
/*
* Print out stats on stderr
*/
if(zcat_flg == 0 && !quiet) {
#ifdef DEBUG
fprintf( stderr,
"%ld chars in, %ld codes (%ld bytes) out, compression factor: ",
in_count, out_count, bytes_out );
prratio( stderr, in_count, bytes_out );
fprintf( stderr, "\n");
fprintf( stderr, "\tCompression as in compact: " );
prratio( stderr, in_count-bytes_out, in_count );
fprintf( stderr, "\n");
fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n",
free_ent - 1, n_bits );
#else /* !DEBUG */
fprintf( stderr, "Compression: " );
prratio( stderr, in_count-bytes_out, in_count );
#endif /* DEBUG */
}
if(bytes_out > in_count) /* exit(2) if no savings */
exit_stat = 2;
return;
}
/*****************************************************************
* TAG( output )
*
* Output the given code.
* Inputs:
* code: A n_bits-bit integer. If == -1, then EOF. This assumes
* that n_bits =< (long)wordsize - 1.
* Outputs:
* Outputs code to the file.
* Assumptions:
* Chars are 8 bits long.
* Algorithm:
* Maintain a BITS character long buffer (so that 8 codes will
* fit in it exactly). Use the VAX insv instruction to insert each
* code in turn. When the buffer fills up empty it and start over.
*/
static char buf[BITS];
#ifndef vax
char_type lmask[9] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00};
char_type rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
#endif /* vax */
output( code )
code_int code;
{
#ifdef DEBUG
static int col = 0;
#endif /* DEBUG */
/*
* On the VAX, it is important to have the register declarations
* in exactly the order given, or the asm will break.
*/
register int r_off = offset, bits= n_bits;
register char * bp = buf;
#ifdef DEBUG
if ( verbose )
fprintf( stderr, "%5d%c", code,
(col+=6) >= 74 ? (col = 0, '\n') : ' ' );
#endif /* DEBUG */
if ( code >= 0 ) {
#ifdef vax
/* VAX DEPENDENT!! Implementation on other machines is below.
*
* Translation: Insert BITS bits from the argument starting at
* offset bits from the beginning of buf.
*/
0; /* Work around for pcc -O bug with asm and if stmt */
asm( "insv 4(ap),r11,r10,(r9)" );
#else /* not a vax */
/*
* byte/bit numbering on the VAX is simulated by the following code
*/
/*
* Get to the first byte.
*/
bp += (r_off >> 3);
r_off &= 7;
/*
* Since code is always >= 8 bits, only need to mask the first
* hunk on the left.
*/
*bp = (*bp & rmask[r_off]) | (code << r_off) & lmask[r_off];
bp++;
bits -= (8 - r_off);
code >>= 8 - r_off;
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
if ( bits >= 8 ) {
*bp++ = code;
code >>= 8;
bits -= 8;
}
/* Last bits. */
if(bits)
*bp = code;
#endif /* vax */
offset += n_bits;
if ( offset == (n_bits << 3) ) {
bp = buf;
bits = n_bits;
bytes_out += bits;
do
putchar(*bp++);
while(--bits);
offset = 0;
}
/*
* If the next entry is going to be too big for the code size,
* then increase it, if possible.
*/
if ( free_ent > maxcode || (clear_flg > 0))
{
/*
* Write the whole buffer, because the input side won't
* discover the size increase until after it has read it.
*/
if ( offset > 0 ) {
if( fwrite( buf, 1, n_bits, stdout ) != n_bits)
writeerr();
bytes_out += n_bits;
}
offset = 0;
if ( clear_flg ) {
maxcode = MAXCODE (n_bits = INIT_BITS);
clear_flg = 0;
}
else {
n_bits++;
if ( n_bits == maxbits )
maxcode = maxmaxcode;
else
maxcode = MAXCODE(n_bits);
}
#ifdef DEBUG
if ( debug ) {
fprintf( stderr, "\nChange to %d bits\n", n_bits );
col = 0;
}
#endif /* DEBUG */
}
} else {
/*
* At EOF, write the rest of the buffer.
*/
if ( offset > 0 )
fwrite( buf, 1, (offset + 7) / 8, stdout );
bytes_out += (offset + 7) / 8;
offset = 0;
fflush( stdout );
#ifdef DEBUG
if ( verbose )
fprintf( stderr, "\n" );
#endif /* DEBUG */
if( ferror( stdout ) )
writeerr();
}
}
/*
* Decompress stdin to stdout. This routine adapts to the codes in the
* file building the "string" table on-the-fly; requiring no table to
* be stored in the compressed file. The tables used herein are shared
* with those of the compress() routine. See the definitions above.
*/
decompress() {
register char_type *stackp;
register int finchar;
register code_int code, oldcode, incode;
/*
* As above, initialize the first 256 entries in the table.
*/
maxcode = MAXCODE(n_bits = INIT_BITS);
for ( code = 255; code >= 0; code-- ) {
tab_prefixof(code) = 0;
tab_suffixof(code) = (char_type)code;
}
free_ent = ((block_compress) ? FIRST : 256 );
finchar = oldcode = getcode();
if(oldcode == -1) /* EOF already? */
return; /* Get out of here */
putchar( (char)finchar ); /* first code must be 8 bits = char */
if(ferror(stdout)) /* Crash if can't write */
writeerr();
stackp = de_stack;
while ( (code = getcode()) > -1 ) {
if ( (code == CLEAR) && block_compress ) {
for ( code = 255; code >= 0; code-- )
tab_prefixof(code) = 0;
clear_flg = 1;
free_ent = FIRST - 1;
if ( (code = getcode ()) == -1 ) /* O, untimely death! */
break;
}
incode = code;
/*
* Special case for KwKwK string.
*/
if ( code >= free_ent ) {
*stackp++ = finchar;
code = oldcode;
}
/*
* Generate output characters in reverse order
*/
#ifdef SIGNED_COMPARE_SLOW
while ( ((unsigned long)code) >= ((unsigned long)256) ) {
#else
while ( code >= 256 ) {
#endif
*stackp++ = tab_suffixof(code);
code = tab_prefixof(code);
}
*stackp++ = finchar = tab_suffixof(code);
/*
* And put them out in forward order
*/
do
putchar ( *--stackp );
while ( stackp > de_stack );
/*
* Generate the new entry.
*/
if ( (code=free_ent) < maxmaxcode ) {
tab_prefixof(code) = (unsigned short)oldcode;
tab_suffixof(code) = finchar;
free_ent = code+1;
}
/*
* Remember previous code.
*/
oldcode = incode;
}
fflush( stdout );
if(ferror(stdout))
writeerr();
}
/*****************************************************************
* TAG( getcode )
*
* Read one code from the standard input. If EOF, return -1.
* Inputs:
* stdin
* Outputs:
* code or -1 is returned.
*/
code_int
getcode() {
/*
* On the VAX, it is important to have the register declarations
* in exactly the order given, or the asm will break.
*/
register code_int code;
static int offset = 0, size = 0;
static char_type buf[BITS];
register int r_off, bits;
register char_type *bp = buf;
if ( clear_flg > 0 || offset >= size || free_ent > maxcode ) {
/*
* If the next entry will be too big for the current code
* size, then we must increase the size. This implies reading
* a new buffer full, too.
*/
if ( free_ent > maxcode ) {
n_bits++;
if ( n_bits == maxbits )
maxcode = maxmaxcode; /* won't get any bigger now */
else
maxcode = MAXCODE(n_bits);
}
if ( clear_flg > 0) {
maxcode = MAXCODE (n_bits = INIT_BITS);
clear_flg = 0;
}
size = fread( buf, 1, n_bits, stdin );
if ( size <= 0 )
return -1; /* end of file */
offset = 0;
/* Round size down to integral number of codes */
size = (size << 3) - (n_bits - 1);
}
r_off = offset;
bits = n_bits;
#ifdef vax
asm( "extzv r10,r9,(r8),r11" );
#else /* not a vax */
/*
* Get to the first byte.
*/
bp += (r_off >> 3);
r_off &= 7;
/* Get first part (low order bits) */
#ifdef NO_UCHAR
code = ((*bp++ >> r_off) & rmask[8 - r_off]) & 0xff;
#else
code = (*bp++ >> r_off);
#endif /* NO_UCHAR */
bits -= (8 - r_off);
r_off = 8 - r_off; /* now, offset into code word */
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
if ( bits >= 8 ) {
#ifdef NO_UCHAR
code = code | ((*bp++ & 0xff) << r_off);
#else
code |= *bp++ << r_off;
#endif /* NO_UCHAR */
r_off += 8;
bits -= 8;
}
/* high order bits. */
code = code | ((*bp & rmask[bits]) << r_off);
#endif /* vax */
offset += n_bits;
return code;
}
char *
rindex(s, c) /* For those who don't have it in libc.a */
register char *s, c;
{
char *p;
for (p = NULL; *s; s++)
if (*s == c)
p = s;
return(p);
}
#ifdef DEBUG
printcodes()
{
/*
* Just print out codes from input file. For debugging.
*/
code_int code;
int col = 0, bits;
bits = n_bits = INIT_BITS;
maxcode = MAXCODE(n_bits);
free_ent = ((block_compress) ? FIRST : 256 );
while ( ( code = getcode() ) >= 0 ) {
if ( (code == CLEAR) && block_compress ) {
free_ent = FIRST - 1;
clear_flg = 1;
}
else if ( free_ent < maxmaxcode )
free_ent++;
if ( bits != n_bits ) {
fprintf(stderr, "\nChange to %d bits\n", n_bits );
bits = n_bits;
col = 0;
}
fprintf(stderr, "%5d%c", code, (col+=6) >= 74 ? (col = 0, '\n') : ' ' );
}
putc( '\n', stderr );
exit( 0 );
}
code_int sorttab[1<<BITS]; /* sorted pointers into htab */
dump_tab() /* dump string table */
{
register int i, first;
register ent;
#define STACK_SIZE 15000
int stack_top = STACK_SIZE;
register c;
if(do_decomp == 0) { /* compressing */
register int flag = 1;
for(i=0; i<hsize; i++) { /* build sort pointers */
if((long)htabof(i) >= 0) {
sorttab[codetabof(i)] = i;
}
}
first = block_compress ? FIRST : 256;
for(i = first; i < free_ent; i++) {
fprintf(stderr, "%5d: \"", i);
de_stack[--stack_top] = '\n';
de_stack[--stack_top] = '"';
stack_top = in_stack((htabof(sorttab[i])>>maxbits)&0xff,
stack_top);
for(ent=htabof(sorttab[i]) & ((1<<maxbits)-1);
ent > 256;
ent=htabof(sorttab[ent]) & ((1<<maxbits)-1)) {
stack_top = in_stack(htabof(sorttab[ent]) >> maxbits,
stack_top);
}
stack_top = in_stack(ent, stack_top);
fwrite( &de_stack[stack_top], 1, STACK_SIZE-stack_top, stderr);
stack_top = STACK_SIZE;
}
} else if(!debug) { /* decompressing */
for ( i = 0; i < free_ent; i++ ) {
ent = i;
c = tab_suffixof(ent);
if ( isascii(c) && isprint(c) )
fprintf( stderr, "%5d: %5d/'%c' \"",
ent, tab_prefixof(ent), c );
else
fprintf( stderr, "%5d: %5d/\\%03o \"",
ent, tab_prefixof(ent), c );
de_stack[--stack_top] = '\n';
de_stack[--stack_top] = '"';
for ( ; ent != NULL;
ent = (ent >= FIRST ? tab_prefixof(ent) : NULL) ) {
stack_top = in_stack(tab_suffixof(ent), stack_top);
}
fwrite( &de_stack[stack_top], 1, STACK_SIZE - stack_top, stderr );
stack_top = STACK_SIZE;
}
}
}
int
in_stack(c, stack_top)
register c, stack_top;
{
if ( (isascii(c) && isprint(c) && c != '\\') || c == ' ' ) {
de_stack[--stack_top] = c;
} else {
switch( c ) {
case '\n': de_stack[--stack_top] = 'n'; break;
case '\t': de_stack[--stack_top] = 't'; break;
case '\b': de_stack[--stack_top] = 'b'; break;
case '\f': de_stack[--stack_top] = 'f'; break;
case '\r': de_stack[--stack_top] = 'r'; break;
case '\\': de_stack[--stack_top] = '\\'; break;
default:
de_stack[--stack_top] = '0' + c % 8;
de_stack[--stack_top] = '0' + (c / 8) % 8;
de_stack[--stack_top] = '0' + c / 64;
break;
}
de_stack[--stack_top] = '\\';
}
return stack_top;
}
#endif /* DEBUG */
writeerr()
{
perror ( ofname );
unlink ( ofname );
exit ( 1 );
}
copystat(ifname, ofname)
char *ifname, *ofname;
{
#ifndef OS9
struct stat statbuf;
int mode;
time_t timep[2];
#endif
fclose(stdin);
fclose(stdout);
#ifndef OS9
if (stat(ifname, &statbuf)) { /* Get stat on input file */
perror(ifname);
return;
}
if ((statbuf.st_mode & S_IFMT/*0170000*/) != S_IFREG/*0100000*/) {
if(quiet)
fprintf(stderr, "%s: ", ifname);
fprintf(stderr, " -- not a regular file: unchanged");
exit_stat = 1;
#ifdef datageneral
#else
} else if (statbuf.st_nlink > 1) {
if(quiet)
fprintf(stderr, "%s: ", ifname);
fprintf(stderr, " -- has %d other links: unchanged",
statbuf.st_nlink - 1);
exit_stat = 1;
#endif datageneral
} else if (exit_stat == 2 && (!force)) { /* No compression: remove file.Z */
if(!quiet)
fprintf(stderr, " -- file unchanged");
} else { /* ***** Successful Compression ***** */
exit_stat = 0;
mode = statbuf.st_mode & 07777;
if (chmod(ofname, mode)) /* Copy modes */
perror(ofname);
#ifdef datageneral
#else
chown(ofname, statbuf.st_uid, statbuf.st_gid); /* Copy ownership */
#endif datageneral
timep[0] = statbuf.st_atime;
timep[1] = statbuf.st_mtime;
utime(ofname, timep); /* Update last accessed and modified times */
#endif /* #ifndef OS9 */
if (unlink(ifname)) /* Remove input file */
perror(ifname);
if(!quiet)
fprintf(stderr, " -- replaced with %s", ofname);
return; /* Successful return */
#ifndef OS9
}
#endif
/* Unsuccessful return -- one of the tests failed */
if (unlink(ofname))
perror(ofname);
}
/*
* This routine returns 1 if we are running in the foreground and stderr
* is a tty.
*/
foreground()
{
if(bgnd_flag) { /* background? */
return(0);
} else { /* foreground */
if(isatty(2)) { /* and stderr is a tty */
return(1);
} else {
return(0);
}
}
}
onintr ( )
{
unlink ( ofname );
exit ( 1 );
}
#ifdef SIGSEGV
oops ( ) /* wild pointer -- assume bad input */
{
if ( do_decomp == 1 )
fprintf ( stderr, "uncompress: corrupt input\n" );
unlink ( ofname );
exit ( 1 );
}
#endif
cl_block () /* table clear for block compress */
{
register long int rat;
checkpoint = in_count + CHECK_GAP;
#ifdef DEBUG
if ( debug ) {
fprintf ( stderr, "count: %ld, ratio: ", in_count );
prratio ( stderr, in_count, bytes_out );
fprintf ( stderr, "\n");
}
#endif /* DEBUG */
if(in_count > 0x007fffff) { /* shift will overflow */
rat = bytes_out >> 8;
if(rat == 0) { /* Don't divide by zero */
rat = 0x7fffffff;
} else {
rat = in_count / rat;
}
} else {
rat = (in_count << 8) / bytes_out; /* 8 fractional bits */
}
if ( rat > ratio ) {
ratio = rat;
} else {
ratio = 0;
#ifdef DEBUG
if(verbose)
dump_tab(); /* dump string table */
#endif
cl_hash ( (count_int) hsize );
free_ent = FIRST;
clear_flg = 1;
output ( (code_int) CLEAR );
#ifdef DEBUG
if(debug)
fprintf ( stderr, "clear\n" );
#endif /* DEBUG */
}
}
cl_hash(hsize) /* reset code table */
register count_int hsize;
{
#ifndef XENIX_16 /* Normal machine */
register count_int *htab_p = htab+hsize;
#else
register j;
register long k = hsize;
register count_int *htab_p;
#endif
register long i;
register long m1 = -1;
#ifdef XENIX_16
for(j=0; j<=8 && k>=0; j++,k-=8192) {
i = 8192;
if(k < 8192) {
i = k;
}
htab_p = &(htab[j][i]);
i -= 16;
if(i > 0) {
#else
i = hsize - 16;
#endif
do { /* might use Sys V memset(3) here */
*(htab_p-16) = m1;
*(htab_p-15) = m1;
*(htab_p-14) = m1;
*(htab_p-13) = m1;
*(htab_p-12) = m1;
*(htab_p-11) = m1;
*(htab_p-10) = m1;
*(htab_p-9) = m1;
*(htab_p-8) = m1;
*(htab_p-7) = m1;
*(htab_p-6) = m1;
*(htab_p-5) = m1;
*(htab_p-4) = m1;
*(htab_p-3) = m1;
*(htab_p-2) = m1;
*(htab_p-1) = m1;
htab_p -= 16;
} while ((i -= 16) >= 0);
#ifdef XENIX_16
}
}
#endif
for ( i += 16; i > 0; i-- )
*--htab_p = m1;
}
prratio(stream, num, den)
FILE *stream;
long int num, den;
{
register int q; /* Doesn't need to be long */
if(num > 214748L) { /* 2147483647/10000 */
q = num / (den / 10000L);
} else {
q = 10000L * num / den; /* Long calculations, though */
}
if (q < 0) {
putc('-', stream);
q = -q;
}
fprintf(stream, "%d.%02d%%", q / 100, q % 100);
}
version()
{
fprintf(stderr, "%s\n", rcs_ident);
fprintf(stderr, "Options: ");
#ifdef vax
fprintf(stderr, "vax, ");
#endif
#ifdef NO_UCHAR
fprintf(stderr, "NO_UCHAR, ");
#endif
#ifdef SIGNED_COMPARE_SLOW
fprintf(stderr, "SIGNED_COMPARE_SLOW, ");
#endif
#ifdef XENIX_16
fprintf(stderr, "XENIX_16, ");
#endif
#ifdef COMPATIBLE
fprintf(stderr, "COMPATIBLE, ");
#endif
#ifdef DEBUG
fprintf(stderr, "DEBUG, ");
#endif
#ifdef BSD4_2
fprintf(stderr, "BSD4_2, ");
#endif
#ifdef OS9
fprintf(stderr, "OS-9, ");
#endif
fprintf(stderr, "BITS = %d\n", BITS);
}
#ifdef amiga
/*
* Dummy calls that are not supported on the Amiga...
*/
chmod ()
{
return (0);
}
chown ()
{
return (0);
}
utime ()
{
return (0);
}
#ifdef lattice
isatty ()
{
return (1); /* Just assume true... */
}
#endif
#ifdef manx /* STILL causes undefined ref's to sys_ stuff in 3.30E */
perror (arg)
char *arg;
{
if (arg && *arg) {
fprintf (stderr, "%s: ", arg);
}
fprintf (stderr, "<unknown error>\n");
}
#endif
#endif
#ifdef OS9
perror (arg)
char *arg;
{
if (arg && *arg) {
fprintf (stderr, "%s: ", arg);
}
fprintf (stderr, "<unknown error>\n");
}
#endif
SHAR_EOF
fi # end of overwriting check
if test -f 'compress.hlp'
then
echo shar: will not over-write existing file "'compress.hlp'"
else
cat << \SHAR_EOF > 'compress.hlp'
USAGE
compress [-dfvc] [-b maxbits] [file ...]
DESCRIPTION
Compress uses Modified Lempel-Ziv-Welch compression to compress
the named input files (or standard input if none are specified).
Each named file is compressed, then, if the compression results in a
smaller file, the compressed file replaces the original file. The
compressed filename is the original with the suffix .Z. Using the
-d option, the specified files (or standard input if none are specified)
will be decompressed, and the decompressed file will replace the
compressed version.
OPTIONS
-d Decompress the specified files.
-c send all output to standard out.
In particular, compress -dc will decompress the file
and send the result to standard out without deleting the
original file, providing a way to list a compressed file
directly.
-f Force the output file to be generated, even if no savings
result.
-v Write compression statistics.
-b maxbits Set the maximum number of bits/code. Generally, more bits
will result in better compression.
CAVEATS
This utility is fully compatible with the standard "compress" program
in use on many UNIX and VMS systems. Since memory is limited under OS9/6809,
though, the maximum bitsize is limited to 12. Files compressed with a larger
bitsize setting cannot be correctly decompressed by this program.
AUTHORS
Spencer Thomas, Jim McKie, Steve Davies, Ken Turkowski, James Woods,
Joe Orost. Ported to OS9/6809 by Simmule Turner(simmy@nu.cs.fsu.edu).
SHAR_EOF
fi # end of overwriting check
# End of shell archive
exit 0
--
Simmule Turner |Arpa: simmy@nu.cs.fsu.edu | "Wait until it is
Florida State Univ |Uucp: gatech!nu.cs.fsu.edu!simmy | finished, it will
444 OSB | Cis: 70651,67 Genie:simmy | be great"
Tallahassee, FL 32306 | Tel: +1 904 644 1573 | simmy