ahh@j.cc.purdue.edu (Brent L. Woods) (03/13/88)
Program Name: compress
Submitted By: Brent Woods (ahh@j.cc.purdue.edu)
Summary: File compression utility; same as UNIX compress.
Poster Boy: Brent Woods (ahh@j.cc.purdue.edu)
Tested. Shar archive. Part 1 of 1.
NOTES: This shar archive contains a notes/documentation file, a
makefile for Manx (3.4a), and the program's C source code
itself.
Brent Woods, Co-Moderator, comp.{sources,binaries}.amiga
USENET: ...!j.cc.purdue.edu!ahh ARPANET: ahh@j.cc.purdue.edu
BITNET: PODUM@PURCCVM PHONE: +1 (317) 743-8421
USNAIL: 320 Brown St., #406 / West Lafayette, IN 47906
================================================================
# This is a shell archive.
# Remove everything above and including the cut line.
# Then run the rest of the file through sh.
#----cut here-----cut here-----cut here-----cut here----#
#!/bin/sh
# shar: Shell Archiver
# Run the following text with /bin/sh to create:
# notes
# Makefile
# compress.c
# This archive created: Sat Mar 12 21:03:45 1988
# By: Brent L. Woods (Co-Moderators Unlimited.)
cat << \SHAR_EOF > notes
Well, here it finally is. A (another?) version of the UNIX
compress for the Amiga. We've tried this on files compressed on a UNIX
machine and then downloaded to an Amiga, and it uncompressed fine.
Why, you ask, have I spent my time working on a version of compress
when there's a perfectly serviceable one on Fish Disk 6 (and on Fish
Disk 51)? Well, this way you get the source. You also get someone to
complain to when things go wrong. :-) I've tried to make this
compress work as much like the UNIX version as possible, but I have to
admit I've failed. When you compress a file that, after the appending
of the ".Z" to the end of the original file name, matches an existing
file, the UNIX version prompts the user to see whether or not he wants
the existing file overwritten. This version doesn't. It doesn't
overwrite by default, although you can force overwriting with the "-f"
option on the command line. If anyone would like to fix this small
problem, be my guest. Please let me know what you had to do though.
I'd really like to know. Sometimes, working on this has made me want
to do something easier, like modern physics... In any case, this
version works, and you get some documentation, too. It's set to
default to a maximum of 13 bit codes, though this can be changed. You
don't get much in the way of great leaps of performance, though. You
can go all the way up to 16 bit codes, but the user should be warned
that a 16 bit version eats almost half a megabyte of memory during
execution. This makes 16 bit codes a bit impractical for 512K
machines, to say the least.
If you have any questions, comments, or war stories, my mail box is
always open.
DOCUMENTATION:
Documentation for all the command line options is in comments in
the code itself. The big, important ones are:
-b nn Number of bits to use as a maximum in generating the
program's operating codes. Normally, nn will range
from 12 to 16, but the program is currently set for
a max of 13. 12 is a good choice for transferring
files to machines with small space areas for programs
(e.g., 64K size).
-v Verbose mode. Prints the filename, compression
efficiency (a percentage value denoting how much
smaller the result is than the original), and the
new filename (typically filename.Z).
-d Decompress. This is how you can take a compressed
file and return it to its original form. The same
thing can be accomplished by naming the binary (or
a copy of it) "uncompress".
-c Catenate. Take a compressed file and cat it to the
screen in uncompressed form. This is the default if
the binary is named "zcat".
-f Force output writing. Forces overwriting in the
event of filename conflicts.
That's about it. Enjoy.
SHAR_EOF
cat << \SHAR_EOF > Makefile
CFLAGS = +pCD -Damiga
SOURCES=compress.c
OBJECTS=compress.o
all: $(OBJECTS)
ln -o compress $(OBJECTS) -lcl32
.c.o: $(SOURCES)
cc $(CFLAGS) $*.c
SHAR_EOF
cat << \SHAR_EOF > compress.c
/*
* Compress - data compression program
*/
/*
* machine variants which require cc -Dmachine: pdp11, z8000, pcxt
*/
/*
* Set USERMEM to the maximum amount of physical user memory available
* in bytes. USERMEM is used to determine the maximum BITS that can be used
* for compression.
*
* SACREDMEM is the amount of physical memory saved for others; compress
* will hog the rest.
*/
#ifndef SACREDMEM
#define SACREDMEM 0
#endif
#ifndef USERMEM
# define USERMEM 450000 /* default user memory */
#endif
#ifdef interdata /* (Perkin-Elmer) */
#define SIGNED_COMPARE_SLOW /* signed compare is slower than unsigned */
#endif
#ifdef UNUSED
#ifdef amiga
# undef USERMEM
# ifdef TINY
# define BITS 14 /* Requires about 128000 bytes free */
# else
# define BITS 15 /* Requires about 230000 bytes free */
# endif
#endif
#endif
#ifdef pdp11
# define BITS 12 /* max bits/code for 16-bit machine */
# define NO_UCHAR /* also if "unsigned char" functions as signed char */
# undef USERMEM
#endif /* pdp11--don't forget to compile with -i */
/* This dosen't need to be here, but I want to force it for now */
#ifdef amiga
# define BITS 13
# undef USERMEM
#endif amiga
#ifdef z8000
# define BITS 12
# undef vax /* weird preprocessor */
# undef USERMEM
#endif /* z8000 */
#ifdef pcxt
# define BITS 12
# undef USERMEM
#endif /* pcxt */
#ifdef USERMEM
# if USERMEM >= (433484+SACREDMEM)
# define PBITS 16
# else
# if USERMEM >= (229600+SACREDMEM)
# define PBITS 15
# else
# if USERMEM >= (127536+SACREDMEM)
# define PBITS 14
# else
# if USERMEM >= (73464+SACREDMEM)
# define PBITS 13
# else
# define PBITS 12
# endif
# endif
# endif
# endif
# undef USERMEM
#endif /* USERMEM */
#ifdef PBITS /* Preferred BITS for this memory size */
# ifndef BITS
# define BITS PBITS
# endif BITS
#endif /* PBITS */
#if BITS == 16
# define HSIZE 69001L /* 95% occupancy */
#endif
#if BITS == 15
# define HSIZE 35023L /* 94% occupancy */
#endif
#if BITS == 14
# define HSIZE 18013 /* 91% occupancy */
#endif
#if BITS == 13
# define HSIZE 9001 /* 91% occupancy */
#endif
#if BITS <= 12
# define HSIZE 5003 /* 80% occupancy */
#endif
#ifdef M_XENIX /* Stupid compiler can't handle arrays with */
# if BITS == 16 /* more than 65535 bytes - so we fake it */
# define XENIX_16
# else
# if BITS > 13 /* Code only handles BITS = 12, 13, or 16 */
# define BITS 13
# endif
# endif
#endif
/*
* a code_int must be able to hold 2**BITS values of type int, and also -1
*/
#if BITS > 15
typedef long int code_int;
#else
typedef int code_int;
#endif
#ifdef SIGNED_COMPARE_SLOW
typedef unsigned long int count_int;
typedef unsigned short int count_short;
#else
typedef long int count_int;
#endif
#ifdef NO_UCHAR
typedef char char_type;
#else
typedef unsigned char char_type;
#endif /* UCHAR */
char_type magic_header[] = { "\037\235" }; /* 1F 9D */
/* 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)
*
*/
#include <stdio.h>
#include <ctype.h>
#include <signal.h>
#ifdef unix
#include <sys/types.h>
#include <sys/stat.h>
#else
#ifdef amiga
#include <exec/types.h> /* Use our own version of types.h */
#include <stat.h> /* Use our own version of stat */
#endif
#endif
#ifdef amiga
#undef getchar() /* Make sure that getchar() and putchar() */
#undef putchar() /* are correctly defined, since the boys */
#define getchar() getc(stdin) /* at Manx pulled a real bimby move in */
#define putchar(c) putc(c, stdout) /* stdio.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 [-dhDVfc] [-b maxbits] [file ...]\n");
}
int debug = 0;
#else
fprintf(stderr,"Usage: compress [-dhfvcV] [-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 [-dhfvc] [-b bits] [file ...]
* Inputs:
* -d: If given, decompression is done instead.
*
* -h: Print usage information.
*
* -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, *rind(), *malloc();
struct stat statbuf;
extern onintr(), oops();
int rtp; /* Read That Puppy! */
char response[2];
int please;
#if (unix || (amiga && lattice))
if ( (bgnd_flag = signal ( SIGINT, SIG_IGN )) != SIG_IGN ) {
signal ( SIGINT, onintr );
#ifdef SIGSEGV
signal ( SIGSEGV, oops );
#endif
}
#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 = rind(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
* -h => print help
* -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':
do_decomp = 1;
zcat_flg = 1;
break;
case 'q':
quiet = 1;
break;
case 'h':
fprintf(stderr, "compress: ");
Usage();
exit(0);
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 */
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 */
if ((freopen(*fileptr, "r", stdin)) == NULL) {
perror(*fileptr); continue;
}
stat ( *fileptr, &statbuf );
fsize = (long) statbuf.st_size;
/*
* 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;
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 );
/* Generate output filename */
strcpy(ofname, *fileptr);
#if !(BSD4_2 || amiga) /* Short filenames */
if ((cp=rind(ofname,'/')) != NULL) cp++;
else cp = ofname;
if (strlen(cp) > 12) {
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) {
if (stat(ofname, &statbuf) == 0) {
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);
/* while ((rtp = agetc(stdin)) != '\n') { */
/* if (rtp == 'y') {
response[0] = 'y';
} */
}
if (response[0] != 'y') {
fprintf(stderr, "\n\tnot overwritten;\n");
fprintf(stderr, "\tuse -f option to force overwrite.\n");
continue;
}
}
}
if(zcat_flg == 0) { /* Open output file */
if (freopen(ofname, "w", stdout) == NULL) {
perror(ofname);
continue;
}
if(!quiet)
fprintf(stderr, "%s: ", *fileptr);
fflush(stderr);
}
/* 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 );
fflush(stderr);
prratio( stderr, in_count, bytes_out );
fflush(stderr);
fprintf( stderr, "\n");
fflush(stderr);
fprintf( stderr, "\tCompression as in compact: " );
fflush(stderr);
prratio( stderr, in_count-bytes_out, in_count );
fflush(stderr);
fprintf( stderr, "\n");
fflush(stderr);
fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n",
free_ent - 1, n_bits );
fflush(stderr);
#else /* !DEBUG */
fprintf( stderr, "Compression: " );
fflush(stderr);
prratio( stderr, in_count-bytes_out, in_count );
fflush(stderr);
#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" );
fflush(stderr);
#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 |= (*bp++ & 0xff) << r_off;
#else
code |= *bp++ << r_off;
#endif /* NO_UCHAR */
r_off += 8;
bits -= 8;
}
/* high order bits. */
code |= (*bp & rmask[bits]) << r_off;
#endif /* vax */
offset += n_bits;
return code;
}
char *
rind(s, c) /* For those who don't have rindex 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') : ' ' );
fflush(stderr);
}
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;
{
struct stat statbuf;
int mode;
#ifndef amiga
time_t timep[2];
#endif amiga
fclose(stdin);
fclose(stdout);
if (stat(ifname, &statbuf)) { /* Get stat on input file */
perror(ifname);
return;
}
#ifndef amiga
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;
} 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;
} 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;
/* ifndef amiga */
if (chmod(ofname, mode)) /* Copy modes */
perror(ofname);
chown(ofname, statbuf.st_uid, statbuf.st_gid); /* Copy ownership */
timep[0] = statbuf.st_atime;
timep[1] = statbuf.st_mtime;
utime(ofname, timep); /* Update last accessed and modified times */
#endif amiga
if (unlink(ifname)) /* Remove input file */
perror(ifname);
if(!quiet)
fprintf(stderr, " -- replaced with %s", ofname);
fflush(stderr);
return; /* Successful return */
#ifndef amiga
}
#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
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
SHAR_EOF
# End of shell archive
exit 0