2 cb58f329 2020-01-15 crossd * compress - File compression ala IEEE Computer, June 1984.
4 cb58f329 2020-01-15 crossd * Algorithm from "A Technique for High Performance Data Compression",
5 cb58f329 2020-01-15 crossd * Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19.
7 cb58f329 2020-01-15 crossd * Usage: compress [-dfvc] [-b bits] [file ...]
9 cb58f329 2020-01-15 crossd * -b: limit the max number of bits/code.
10 cb58f329 2020-01-15 crossd * -c: write output on stdout, don't remove original.
11 cb58f329 2020-01-15 crossd * -d: decompress instead.
12 cb58f329 2020-01-15 crossd * -f: Forces output file to be generated, even if one already
13 cb58f329 2020-01-15 crossd * exists, and even if no space is saved by compressing.
14 cb58f329 2020-01-15 crossd * If -f is not used, the user will be prompted if stdin is
15 cb58f329 2020-01-15 crossd * a tty, otherwise, the output file will not be overwritten.
16 cb58f329 2020-01-15 crossd * -v: Write compression statistics
18 cb58f329 2020-01-15 crossd * file ...: Files to be compressed. If none specified, stdin is used.
19 cb58f329 2020-01-15 crossd * Outputs:
20 cb58f329 2020-01-15 crossd * file.Z: Compressed form of file with same mode, owner, and utimes
21 cb58f329 2020-01-15 crossd * or stdout (if stdin used as input)
23 cb58f329 2020-01-15 crossd * Assumptions:
24 cb58f329 2020-01-15 crossd * When filenames are given, replaces with the compressed version
25 cb58f329 2020-01-15 crossd * (.Z suffix) only if the file decreases in size.
26 cb58f329 2020-01-15 crossd * Algorithm:
27 cb58f329 2020-01-15 crossd * Modified Lempel-Ziv method (LZW). Basically finds common
28 cb58f329 2020-01-15 crossd * substrings and replaces them with a variable size code. This is
29 cb58f329 2020-01-15 crossd * deterministic, and can be done on the fly. Thus, the decompression
30 cb58f329 2020-01-15 crossd * procedure needs no input table, but tracks the way the table was built.
32 cb58f329 2020-01-15 crossd * Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
33 cb58f329 2020-01-15 crossd * Jim McKie (decvax!mcvax!jim)
34 cb58f329 2020-01-15 crossd * Steve Davies (decvax!vax135!petsd!peora!srd)
35 cb58f329 2020-01-15 crossd * Ken Turkowski (decvax!decwrl!turtlevax!ken)
36 cb58f329 2020-01-15 crossd * James A. Woods (decvax!ihnp4!ames!jaw)
37 cb58f329 2020-01-15 crossd * Joe Orost (decvax!vax135!petsd!joe)
40 cb58f329 2020-01-15 crossd #ifndef USED
41 cb58f329 2020-01-15 crossd # define USED(x) if(x);else
44 cb58f329 2020-01-15 crossd #define _PLAN9_SOURCE
45 cb58f329 2020-01-15 crossd #define _BSD_EXTENSION
46 cb58f329 2020-01-15 crossd #define _POSIX_SOURCE
48 cb58f329 2020-01-15 crossd #include <u.h>
49 cb58f329 2020-01-15 crossd #include <stdio.h>
50 cb58f329 2020-01-15 crossd #include <ctype.h>
51 cb58f329 2020-01-15 crossd #include <stdlib.h>
52 cb58f329 2020-01-15 crossd #include <unistd.h>
53 cb58f329 2020-01-15 crossd #include <string.h>
54 cb58f329 2020-01-15 crossd #include <signal.h>
55 cb58f329 2020-01-15 crossd #include <utime.h>
56 cb58f329 2020-01-15 crossd #include <sys/types.h>
57 cb58f329 2020-01-15 crossd #include <sys/stat.h>
59 cb58f329 2020-01-15 crossd #define min(a,b) ((a>b) ? b : a)
61 cb58f329 2020-01-15 crossd #define BITS 16
62 cb58f329 2020-01-15 crossd #define HSIZE 69001 /* 95% occupancy */
65 cb58f329 2020-01-15 crossd * a code_int must be able to hold 2**BITS values of type int, and also -1
67 cb58f329 2020-01-15 crossd typedef long code_int;
68 cb58f329 2020-01-15 crossd typedef long count_int;
70 cb58f329 2020-01-15 crossd static char rcs_ident[] = "$Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $";
72 cb58f329 2020-01-15 crossd uchar magic_header[] = { 0x1F, 0x9D }; /* 1F 9D */
74 cb58f329 2020-01-15 crossd /* Defines for third byte of header */
75 cb58f329 2020-01-15 crossd #define BIT_MASK 0x1f
76 cb58f329 2020-01-15 crossd #define BLOCK_MASK 0x80
77 cb58f329 2020-01-15 crossd /* Masks 0x40 and 0x20 are free. I think 0x20 should mean that there is
78 cb58f329 2020-01-15 crossd a fourth header byte (for expansion).
80 cb58f329 2020-01-15 crossd #define INIT_BITS 9 /* initial number of bits/code */
82 cb58f329 2020-01-15 crossd #define ARGVAL() (*++(*argv) || (--argc && *++argv))
84 cb58f329 2020-01-15 crossd int n_bits; /* number of bits/code */
85 cb58f329 2020-01-15 crossd int maxbits = BITS; /* user settable max # bits/code */
86 cb58f329 2020-01-15 crossd code_int maxcode; /* maximum code, given n_bits */
87 cb58f329 2020-01-15 crossd code_int maxmaxcode = 1 << BITS; /* should NEVER generate this code */
89 cb58f329 2020-01-15 crossd #define MAXCODE(n_bits) ((1 << (n_bits)) - 1)
91 cb58f329 2020-01-15 crossd count_int htab[HSIZE];
92 cb58f329 2020-01-15 crossd ushort codetab[HSIZE];
94 cb58f329 2020-01-15 crossd #define htabof(i) htab[i]
95 cb58f329 2020-01-15 crossd #define codetabof(i) codetab[i]
97 cb58f329 2020-01-15 crossd code_int hsize = HSIZE; /* for dynamic table sizing */
98 cb58f329 2020-01-15 crossd count_int fsize;
101 cb58f329 2020-01-15 crossd * To save much memory, we overlay the table used by compress() with those
102 cb58f329 2020-01-15 crossd * used by decompress(). The tab_prefix table is the same size and type
103 cb58f329 2020-01-15 crossd * as the codetab. The tab_suffix table needs 2**BITS characters. We
104 cb58f329 2020-01-15 crossd * get this from the beginning of htab. The output stack uses the rest
105 cb58f329 2020-01-15 crossd * of htab, and contains characters. There is plenty of room for any
106 cb58f329 2020-01-15 crossd * possible stack (stack used to be 8000 characters).
109 cb58f329 2020-01-15 crossd #define tab_prefixof(i) codetabof(i)
110 cb58f329 2020-01-15 crossd #define tab_suffixof(i) ((uchar *)(htab))[i]
111 cb58f329 2020-01-15 crossd #define de_stack ((uchar *)&tab_suffixof(1<<BITS))
113 cb58f329 2020-01-15 crossd code_int free_ent = 0; /* first unused entry */
114 cb58f329 2020-01-15 crossd int exit_stat = 0;
116 cb58f329 2020-01-15 crossd void cl_block(void);
117 cb58f329 2020-01-15 crossd void cl_hash(count_int);
118 cb58f329 2020-01-15 crossd void compress(void);
119 cb58f329 2020-01-15 crossd void copystat(char *, char *);
120 cb58f329 2020-01-15 crossd void decompress(void);
121 cb58f329 2020-01-15 crossd int foreground(void);
122 cb58f329 2020-01-15 crossd code_int getcode(void);
123 cb58f329 2020-01-15 crossd void onintr(int);
124 cb58f329 2020-01-15 crossd void oops(int);
125 cb58f329 2020-01-15 crossd void output(code_int);
126 cb58f329 2020-01-15 crossd void prratio(FILE *, long, long);
127 cb58f329 2020-01-15 crossd void version(void);
128 cb58f329 2020-01-15 crossd void writeerr(void);
131 cb58f329 2020-01-15 crossd Usage(void)
133 cb58f329 2020-01-15 crossd #ifdef DEBUG
134 cb58f329 2020-01-15 crossd fprintf(stderr,"Usage: compress [-cdfDV] [-b maxbits] [file ...]\n");
136 cb58f329 2020-01-15 crossd fprintf(stderr,"Usage: compress [-cdfvV] [-b maxbits] [file ...]\n");
137 cb58f329 2020-01-15 crossd #endif /* DEBUG */
140 cb58f329 2020-01-15 crossd int debug = 0;
141 cb58f329 2020-01-15 crossd int nomagic = 0; /* Use a 3-byte magic number header, unless old file */
142 cb58f329 2020-01-15 crossd int zcat_flg = 0; /* Write output on stdout, suppress messages */
143 cb58f329 2020-01-15 crossd int quiet = 1; /* don't tell me about compression */
146 cb58f329 2020-01-15 crossd * block compression parameters -- after all codes are used up,
147 cb58f329 2020-01-15 crossd * and compression rate changes, start over.
149 cb58f329 2020-01-15 crossd int block_compress = BLOCK_MASK;
150 cb58f329 2020-01-15 crossd int clear_flg = 0;
151 cb58f329 2020-01-15 crossd long ratio = 0;
152 cb58f329 2020-01-15 crossd #define CHECK_GAP 10000 /* ratio check interval */
153 cb58f329 2020-01-15 crossd count_int checkpoint = CHECK_GAP;
155 cb58f329 2020-01-15 crossd * the next two codes should not be changed lightly, as they must not
156 cb58f329 2020-01-15 crossd * lie within the contiguous general code space.
158 cb58f329 2020-01-15 crossd #define FIRST 257 /* first free entry */
159 cb58f329 2020-01-15 crossd #define CLEAR 256 /* table clear output code */
161 cb58f329 2020-01-15 crossd int force = 0;
162 cb58f329 2020-01-15 crossd char ofname [100];
163 cb58f329 2020-01-15 crossd #ifdef DEBUG
164 cb58f329 2020-01-15 crossd int verbose = 0;
165 cb58f329 2020-01-15 crossd #endif /* DEBUG */
166 cb58f329 2020-01-15 crossd void (*bgnd_flag)(int);
168 cb58f329 2020-01-15 crossd int do_decomp = 0;
171 cb58f329 2020-01-15 crossd main(argc, argv)
172 cb58f329 2020-01-15 crossd int argc;
173 cb58f329 2020-01-15 crossd char **argv;
175 cb58f329 2020-01-15 crossd int overwrite = 0; /* Do not overwrite unless given -f flag */
176 cb58f329 2020-01-15 crossd char tempname[512];
177 cb58f329 2020-01-15 crossd char **filelist, **fileptr;
178 cb58f329 2020-01-15 crossd char *cp;
179 cb58f329 2020-01-15 crossd struct stat statbuf;
181 cb58f329 2020-01-15 crossd if ( (bgnd_flag = signal ( SIGINT, SIG_IGN )) != SIG_IGN ) {
182 cb58f329 2020-01-15 crossd signal(SIGINT, onintr);
183 cb58f329 2020-01-15 crossd signal(SIGSEGV, oops);
186 cb58f329 2020-01-15 crossd filelist = fileptr = (char **)(malloc(argc * sizeof(*argv)));
187 cb58f329 2020-01-15 crossd *filelist = NULL;
189 cb58f329 2020-01-15 crossd if((cp = strrchr(argv[0], '/')) != 0)
192 cb58f329 2020-01-15 crossd cp = argv[0];
193 cb58f329 2020-01-15 crossd if(strcmp(cp, "uncompress") == 0)
194 cb58f329 2020-01-15 crossd do_decomp = 1;
195 cb58f329 2020-01-15 crossd else if(strcmp(cp, "zcat") == 0) {
196 cb58f329 2020-01-15 crossd do_decomp = 1;
197 cb58f329 2020-01-15 crossd zcat_flg = 1;
201 cb58f329 2020-01-15 crossd * Argument Processing
202 cb58f329 2020-01-15 crossd * All flags are optional.
203 cb58f329 2020-01-15 crossd * -C generate output compatible with compress 2.0.
204 cb58f329 2020-01-15 crossd * -D debug
205 cb58f329 2020-01-15 crossd * -V print Version; debug verbose
206 cb58f329 2020-01-15 crossd * -b maxbits maxbits. If -b is specified, then maxbits MUST be
207 cb58f329 2020-01-15 crossd * given also.
208 cb58f329 2020-01-15 crossd * -c cat all output to stdout
209 cb58f329 2020-01-15 crossd * -d do_decomp
210 cb58f329 2020-01-15 crossd * -f force overwrite of output file
211 cb58f329 2020-01-15 crossd * -n no header: useful to uncompress old files
212 cb58f329 2020-01-15 crossd * -v unquiet
213 cb58f329 2020-01-15 crossd * if a string is left, must be an input filename.
215 cb58f329 2020-01-15 crossd for (argc--, argv++; argc > 0; argc--, argv++) {
216 cb58f329 2020-01-15 crossd if (**argv == '-') { /* A flag argument */
217 cb58f329 2020-01-15 crossd while (*++(*argv)) { /* Process all flags in this arg */
218 cb58f329 2020-01-15 crossd switch (**argv) {
219 cb58f329 2020-01-15 crossd case 'C':
220 cb58f329 2020-01-15 crossd block_compress = 0;
222 cb58f329 2020-01-15 crossd #ifdef DEBUG
223 cb58f329 2020-01-15 crossd case 'D':
224 cb58f329 2020-01-15 crossd debug = 1;
226 cb58f329 2020-01-15 crossd case 'V':
227 cb58f329 2020-01-15 crossd verbose = 1;
228 cb58f329 2020-01-15 crossd version();
231 cb58f329 2020-01-15 crossd case 'V':
232 cb58f329 2020-01-15 crossd version();
235 cb58f329 2020-01-15 crossd case 'b':
236 cb58f329 2020-01-15 crossd if (!ARGVAL()) {
237 cb58f329 2020-01-15 crossd fprintf(stderr, "Missing maxbits\n");
241 cb58f329 2020-01-15 crossd maxbits = atoi(*argv);
242 cb58f329 2020-01-15 crossd goto nextarg;
243 cb58f329 2020-01-15 crossd case 'c':
244 cb58f329 2020-01-15 crossd zcat_flg = 1;
246 cb58f329 2020-01-15 crossd case 'd':
247 cb58f329 2020-01-15 crossd do_decomp = 1;
249 cb58f329 2020-01-15 crossd case 'f':
250 cb58f329 2020-01-15 crossd case 'F':
251 cb58f329 2020-01-15 crossd overwrite = 1;
252 cb58f329 2020-01-15 crossd force = 1;
254 cb58f329 2020-01-15 crossd case 'n':
255 cb58f329 2020-01-15 crossd nomagic = 1;
257 cb58f329 2020-01-15 crossd case 'q':
258 cb58f329 2020-01-15 crossd quiet = 1;
260 cb58f329 2020-01-15 crossd case 'v':
261 cb58f329 2020-01-15 crossd quiet = 0;
264 cb58f329 2020-01-15 crossd fprintf(stderr, "Unknown flag: '%c'; ", **argv);
269 cb58f329 2020-01-15 crossd } else { /* Input file name */
270 cb58f329 2020-01-15 crossd *fileptr++ = *argv; /* Build input file list */
271 cb58f329 2020-01-15 crossd *fileptr = NULL;
272 cb58f329 2020-01-15 crossd /* process nextarg; */
275 cb58f329 2020-01-15 crossd continue;
278 cb58f329 2020-01-15 crossd if(maxbits < INIT_BITS) maxbits = INIT_BITS;
279 cb58f329 2020-01-15 crossd if (maxbits > BITS) maxbits = BITS;
280 cb58f329 2020-01-15 crossd maxmaxcode = 1 << maxbits;
282 cb58f329 2020-01-15 crossd if (*filelist != NULL) {
283 cb58f329 2020-01-15 crossd for (fileptr = filelist; *fileptr; fileptr++) {
284 cb58f329 2020-01-15 crossd exit_stat = 0;
285 cb58f329 2020-01-15 crossd if (do_decomp != 0) { /* DECOMPRESSION */
286 cb58f329 2020-01-15 crossd /* Check for .Z suffix */
287 cb58f329 2020-01-15 crossd if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") != 0) {
288 cb58f329 2020-01-15 crossd /* No .Z: tack one on */
289 cb58f329 2020-01-15 crossd strcpy(tempname, *fileptr);
290 cb58f329 2020-01-15 crossd strcat(tempname, ".Z");
291 cb58f329 2020-01-15 crossd *fileptr = tempname;
293 cb58f329 2020-01-15 crossd /* Open input file */
294 cb58f329 2020-01-15 crossd if ((freopen(*fileptr, "r", stdin)) == NULL) {
295 cb58f329 2020-01-15 crossd perror(*fileptr);
296 cb58f329 2020-01-15 crossd continue;
298 cb58f329 2020-01-15 crossd /* Check the magic number */
299 cb58f329 2020-01-15 crossd if (nomagic == 0) {
300 cb58f329 2020-01-15 crossd if ((getchar() != (magic_header[0] & 0xFF))
301 cb58f329 2020-01-15 crossd || (getchar() != (magic_header[1] & 0xFF))) {
302 cb58f329 2020-01-15 crossd fprintf(stderr, "%s: not in compressed format\n",
303 cb58f329 2020-01-15 crossd *fileptr);
304 cb58f329 2020-01-15 crossd continue;
306 cb58f329 2020-01-15 crossd maxbits = getchar(); /* set -b from file */
307 cb58f329 2020-01-15 crossd block_compress = maxbits & BLOCK_MASK;
308 cb58f329 2020-01-15 crossd maxbits &= BIT_MASK;
309 cb58f329 2020-01-15 crossd maxmaxcode = 1 << maxbits;
310 cb58f329 2020-01-15 crossd if(maxbits > BITS) {
311 cb58f329 2020-01-15 crossd fprintf(stderr,
312 cb58f329 2020-01-15 crossd "%s: compressed with %d bits, can only handle %d bits\n",
313 cb58f329 2020-01-15 crossd *fileptr, maxbits, BITS);
314 cb58f329 2020-01-15 crossd continue;
317 cb58f329 2020-01-15 crossd /* Generate output filename */
318 cb58f329 2020-01-15 crossd strcpy(ofname, *fileptr);
319 cb58f329 2020-01-15 crossd ofname[strlen(*fileptr) - 2] = '\0'; /* Strip off .Z */
320 cb58f329 2020-01-15 crossd } else { /* COMPRESSION */
321 cb58f329 2020-01-15 crossd if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") == 0) {
322 cb58f329 2020-01-15 crossd fprintf(stderr,
323 cb58f329 2020-01-15 crossd "%s: already has .Z suffix -- no change\n",
324 cb58f329 2020-01-15 crossd *fileptr);
325 cb58f329 2020-01-15 crossd continue;
327 cb58f329 2020-01-15 crossd /* Open input file */
328 cb58f329 2020-01-15 crossd if ((freopen(*fileptr, "r", stdin)) == NULL) {
329 cb58f329 2020-01-15 crossd perror(*fileptr);
330 cb58f329 2020-01-15 crossd continue;
332 cb58f329 2020-01-15 crossd (void) stat(*fileptr, &statbuf);
333 cb58f329 2020-01-15 crossd fsize = (long) statbuf.st_size;
335 cb58f329 2020-01-15 crossd * tune hash table size for small files -- ad hoc,
336 cb58f329 2020-01-15 crossd * but the sizes match earlier #defines, which
337 cb58f329 2020-01-15 crossd * serve as upper bounds on the number of output codes.
339 cb58f329 2020-01-15 crossd hsize = HSIZE;
340 cb58f329 2020-01-15 crossd if (fsize < (1 << 12))
341 cb58f329 2020-01-15 crossd hsize = min(5003, HSIZE);
342 cb58f329 2020-01-15 crossd else if (fsize < (1 << 13))
343 cb58f329 2020-01-15 crossd hsize = min(9001, HSIZE);
344 cb58f329 2020-01-15 crossd else if (fsize < (1 << 14))
345 cb58f329 2020-01-15 crossd hsize = min (18013, HSIZE);
346 cb58f329 2020-01-15 crossd else if (fsize < (1 << 15))
347 cb58f329 2020-01-15 crossd hsize = min (35023, HSIZE);
348 cb58f329 2020-01-15 crossd else if (fsize < 47000)
349 cb58f329 2020-01-15 crossd hsize = min (50021, HSIZE);
351 cb58f329 2020-01-15 crossd /* Generate output filename */
352 cb58f329 2020-01-15 crossd strcpy(ofname, *fileptr);
353 cb58f329 2020-01-15 crossd #ifndef BSD4_2
354 cb58f329 2020-01-15 crossd if ((cp=strrchr(ofname,'/')) != NULL)
357 cb58f329 2020-01-15 crossd cp = ofname;
359 cb58f329 2020-01-15 crossd *** changed 12 to 25; should be NAMELEN-3, but I don't want
360 cb58f329 2020-01-15 crossd * to fight the headers. ehg 5 Nov 92 **
362 cb58f329 2020-01-15 crossd if (strlen(cp) > 25) {
363 cb58f329 2020-01-15 crossd fprintf(stderr, "%s: filename too long to tack on .Z\n",
365 cb58f329 2020-01-15 crossd continue;
368 cb58f329 2020-01-15 crossd strcat(ofname, ".Z");
370 cb58f329 2020-01-15 crossd /* Check for overwrite of existing file */
371 cb58f329 2020-01-15 crossd if (overwrite == 0 && zcat_flg == 0 &&
372 cb58f329 2020-01-15 crossd stat(ofname, &statbuf) == 0) {
373 cb58f329 2020-01-15 crossd char response[2];
375 cb58f329 2020-01-15 crossd response[0] = 'n';
376 cb58f329 2020-01-15 crossd fprintf(stderr, "%s already exists;", ofname);
377 cb58f329 2020-01-15 crossd if (foreground()) {
378 cb58f329 2020-01-15 crossd fprintf(stderr,
379 cb58f329 2020-01-15 crossd " do you wish to overwrite %s (y or n)? ",
381 cb58f329 2020-01-15 crossd fflush(stderr);
382 cb58f329 2020-01-15 crossd (void) read(2, response, 2);
383 cb58f329 2020-01-15 crossd while (response[1] != '\n')
384 cb58f329 2020-01-15 crossd if (read(2, response+1, 1) < 0) {
385 cb58f329 2020-01-15 crossd /* Ack! */
386 cb58f329 2020-01-15 crossd perror("stderr");
390 cb58f329 2020-01-15 crossd if (response[0] != 'y') {
391 cb58f329 2020-01-15 crossd fprintf(stderr, "\tnot overwritten\n");
392 cb58f329 2020-01-15 crossd continue;
395 cb58f329 2020-01-15 crossd if(zcat_flg == 0) { /* Open output file */
396 cb58f329 2020-01-15 crossd if (freopen(ofname, "w", stdout) == NULL) {
397 cb58f329 2020-01-15 crossd perror(ofname);
398 cb58f329 2020-01-15 crossd continue;
400 cb58f329 2020-01-15 crossd if(!quiet)
401 cb58f329 2020-01-15 crossd fprintf(stderr, "%s: ", *fileptr);
404 cb58f329 2020-01-15 crossd /* Actually do the compression/decompression */
405 cb58f329 2020-01-15 crossd if (do_decomp == 0)
406 cb58f329 2020-01-15 crossd compress();
407 cb58f329 2020-01-15 crossd #ifndef DEBUG
409 cb58f329 2020-01-15 crossd decompress();
411 cb58f329 2020-01-15 crossd else if (debug == 0)
412 cb58f329 2020-01-15 crossd decompress();
414 cb58f329 2020-01-15 crossd printcodes();
415 cb58f329 2020-01-15 crossd if (verbose)
416 cb58f329 2020-01-15 crossd dump_tab();
417 cb58f329 2020-01-15 crossd #endif /* DEBUG */
418 cb58f329 2020-01-15 crossd if(zcat_flg == 0) {
419 cb58f329 2020-01-15 crossd copystat(*fileptr, ofname); /* Copy stats */
420 cb58f329 2020-01-15 crossd if (exit_stat == 1 || !quiet)
421 cb58f329 2020-01-15 crossd putc('\n', stderr);
424 cb58f329 2020-01-15 crossd } else { /* Standard input */
425 cb58f329 2020-01-15 crossd if (do_decomp == 0) {
426 cb58f329 2020-01-15 crossd compress();
427 cb58f329 2020-01-15 crossd #ifdef DEBUG
428 cb58f329 2020-01-15 crossd if(verbose)
429 cb58f329 2020-01-15 crossd dump_tab();
431 cb58f329 2020-01-15 crossd if(!quiet)
432 cb58f329 2020-01-15 crossd putc('\n', stderr);
434 cb58f329 2020-01-15 crossd /* Check the magic number */
435 cb58f329 2020-01-15 crossd if (nomagic == 0) {
436 cb58f329 2020-01-15 crossd if ((getchar()!=(magic_header[0] & 0xFF))
437 cb58f329 2020-01-15 crossd || (getchar()!=(magic_header[1] & 0xFF))) {
438 cb58f329 2020-01-15 crossd fprintf(stderr, "stdin: not in compressed format\n");
441 cb58f329 2020-01-15 crossd maxbits = getchar(); /* set -b from file */
442 cb58f329 2020-01-15 crossd block_compress = maxbits & BLOCK_MASK;
443 cb58f329 2020-01-15 crossd maxbits &= BIT_MASK;
444 cb58f329 2020-01-15 crossd maxmaxcode = 1 << maxbits;
445 cb58f329 2020-01-15 crossd fsize = 100000; /* assume stdin large for USERMEM */
446 cb58f329 2020-01-15 crossd if(maxbits > BITS) {
447 cb58f329 2020-01-15 crossd fprintf(stderr,
448 cb58f329 2020-01-15 crossd "stdin: compressed with %d bits, can only handle %d bits\n",
449 cb58f329 2020-01-15 crossd maxbits, BITS);
453 cb58f329 2020-01-15 crossd #ifndef DEBUG
454 cb58f329 2020-01-15 crossd decompress();
456 cb58f329 2020-01-15 crossd if (debug == 0)
457 cb58f329 2020-01-15 crossd decompress();
459 cb58f329 2020-01-15 crossd printcodes();
460 cb58f329 2020-01-15 crossd if (verbose)
461 cb58f329 2020-01-15 crossd dump_tab();
462 cb58f329 2020-01-15 crossd #endif /* DEBUG */
465 cb58f329 2020-01-15 crossd exit(exit_stat);
466 cb58f329 2020-01-15 crossd return 0;
469 cb58f329 2020-01-15 crossd static int offset;
470 cb58f329 2020-01-15 crossd long in_count = 1; /* length of input */
471 cb58f329 2020-01-15 crossd long bytes_out; /* length of compressed output */
472 cb58f329 2020-01-15 crossd long out_count = 0; /* # of codes output (for debugging) */
475 cb58f329 2020-01-15 crossd * compress stdin to stdout
477 cb58f329 2020-01-15 crossd * Algorithm: use open addressing double hashing (no chaining) on the
478 cb58f329 2020-01-15 crossd * prefix code / next character combination. We do a variant of Knuth's
479 cb58f329 2020-01-15 crossd * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
480 cb58f329 2020-01-15 crossd * secondary probe. Here, the modular division first probe is gives way
481 cb58f329 2020-01-15 crossd * to a faster exclusive-or manipulation. Also do block compression with
482 cb58f329 2020-01-15 crossd * an adaptive reset, whereby the code table is cleared when the compression
483 cb58f329 2020-01-15 crossd * ratio decreases, but after the table fills. The variable-length output
484 cb58f329 2020-01-15 crossd * codes are re-sized at this point, and a special CLEAR code is generated
485 cb58f329 2020-01-15 crossd * for the decompressor. Late addition: construct the table according to
486 cb58f329 2020-01-15 crossd * file size for noticeable speed improvement on small files. Please direct
487 cb58f329 2020-01-15 crossd * questions about this implementation to ames!jaw.
490 cb58f329 2020-01-15 crossd compress(void)
492 cb58f329 2020-01-15 crossd code_int ent, hsize_reg;
493 cb58f329 2020-01-15 crossd code_int i;
494 cb58f329 2020-01-15 crossd int c, disp, hshift;
495 cb58f329 2020-01-15 crossd long fcode;
497 cb58f329 2020-01-15 crossd if (nomagic == 0) {
498 cb58f329 2020-01-15 crossd putchar(magic_header[0]);
499 cb58f329 2020-01-15 crossd putchar(magic_header[1]);
500 cb58f329 2020-01-15 crossd putchar((char)(maxbits | block_compress));
501 cb58f329 2020-01-15 crossd if(ferror(stdout))
502 cb58f329 2020-01-15 crossd writeerr();
504 cb58f329 2020-01-15 crossd offset = 0;
505 cb58f329 2020-01-15 crossd bytes_out = 3; /* includes 3-byte header mojo */
506 cb58f329 2020-01-15 crossd out_count = 0;
507 cb58f329 2020-01-15 crossd clear_flg = 0;
508 cb58f329 2020-01-15 crossd ratio = 0;
509 cb58f329 2020-01-15 crossd in_count = 1;
510 cb58f329 2020-01-15 crossd checkpoint = CHECK_GAP;
511 cb58f329 2020-01-15 crossd maxcode = MAXCODE(n_bits = INIT_BITS);
512 cb58f329 2020-01-15 crossd free_ent = (block_compress? FIRST: 256);
514 cb58f329 2020-01-15 crossd ent = getchar ();
516 cb58f329 2020-01-15 crossd hshift = 0;
517 cb58f329 2020-01-15 crossd for (fcode = (long)hsize; fcode < 65536L; fcode *= 2)
518 cb58f329 2020-01-15 crossd hshift++;
519 cb58f329 2020-01-15 crossd hshift = 8 - hshift; /* set hash code range bound */
521 cb58f329 2020-01-15 crossd hsize_reg = hsize;
522 cb58f329 2020-01-15 crossd cl_hash( (count_int) hsize_reg); /* clear hash table */
524 cb58f329 2020-01-15 crossd while ((c = getchar()) != EOF) {
525 cb58f329 2020-01-15 crossd in_count++;
526 cb58f329 2020-01-15 crossd fcode = (long) (((long) c << maxbits) + ent);
527 cb58f329 2020-01-15 crossd i = ((c << hshift) ^ ent); /* xor hashing */
529 cb58f329 2020-01-15 crossd if (htabof (i) == fcode) {
530 cb58f329 2020-01-15 crossd ent = codetabof(i);
531 cb58f329 2020-01-15 crossd continue;
532 cb58f329 2020-01-15 crossd } else if ((long)htabof(i) < 0 ) /* empty slot */
533 cb58f329 2020-01-15 crossd goto nomatch;
534 cb58f329 2020-01-15 crossd disp = hsize_reg - i; /* secondary hash (after G. Knott) */
535 cb58f329 2020-01-15 crossd if (i == 0)
536 cb58f329 2020-01-15 crossd disp = 1;
538 cb58f329 2020-01-15 crossd if ((i -= disp) < 0)
539 cb58f329 2020-01-15 crossd i += hsize_reg;
541 cb58f329 2020-01-15 crossd if (htabof (i) == fcode) {
542 cb58f329 2020-01-15 crossd ent = codetabof(i);
543 cb58f329 2020-01-15 crossd continue;
545 cb58f329 2020-01-15 crossd if ((long)htabof(i) > 0)
546 cb58f329 2020-01-15 crossd goto probe;
548 cb58f329 2020-01-15 crossd output((code_int)ent);
549 cb58f329 2020-01-15 crossd out_count++;
551 cb58f329 2020-01-15 crossd if (free_ent < maxmaxcode) {
552 cb58f329 2020-01-15 crossd codetabof(i) = free_ent++; /* code -> hashtable */
553 cb58f329 2020-01-15 crossd htabof(i) = fcode;
554 cb58f329 2020-01-15 crossd } else if ((count_int)in_count >= checkpoint && block_compress)
555 cb58f329 2020-01-15 crossd cl_block ();
558 cb58f329 2020-01-15 crossd * Put out the final code.
560 cb58f329 2020-01-15 crossd output( (code_int)ent );
561 cb58f329 2020-01-15 crossd out_count++;
562 cb58f329 2020-01-15 crossd output( (code_int)-1 );
565 cb58f329 2020-01-15 crossd * Print out stats on stderr
567 cb58f329 2020-01-15 crossd if(zcat_flg == 0 && !quiet) {
568 cb58f329 2020-01-15 crossd #ifdef DEBUG
569 cb58f329 2020-01-15 crossd fprintf( stderr,
570 cb58f329 2020-01-15 crossd "%ld chars in, %ld codes (%ld bytes) out, compression factor: ",
571 cb58f329 2020-01-15 crossd in_count, out_count, bytes_out );
572 cb58f329 2020-01-15 crossd prratio( stderr, in_count, bytes_out );
573 cb58f329 2020-01-15 crossd fprintf( stderr, "\n");
574 cb58f329 2020-01-15 crossd fprintf( stderr, "\tCompression as in compact: " );
575 cb58f329 2020-01-15 crossd prratio( stderr, in_count-bytes_out, in_count );
576 cb58f329 2020-01-15 crossd fprintf( stderr, "\n");
577 cb58f329 2020-01-15 crossd fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n",
578 cb58f329 2020-01-15 crossd free_ent - 1, n_bits );
579 cb58f329 2020-01-15 crossd #else /* !DEBUG */
580 cb58f329 2020-01-15 crossd fprintf( stderr, "Compression: " );
581 cb58f329 2020-01-15 crossd prratio( stderr, in_count-bytes_out, in_count );
582 cb58f329 2020-01-15 crossd #endif /* DEBUG */
584 cb58f329 2020-01-15 crossd if(bytes_out > in_count) /* exit(2) if no savings */
585 cb58f329 2020-01-15 crossd exit_stat = 2;
589 cb58f329 2020-01-15 crossd * TAG( output )
591 cb58f329 2020-01-15 crossd * Output the given code.
592 cb58f329 2020-01-15 crossd * Inputs:
593 cb58f329 2020-01-15 crossd * code: A n_bits-bit integer. If == -1, then EOF. This assumes
594 cb58f329 2020-01-15 crossd * that n_bits =< (long)wordsize - 1.
595 cb58f329 2020-01-15 crossd * Outputs:
596 cb58f329 2020-01-15 crossd * Outputs code to the file.
597 cb58f329 2020-01-15 crossd * Assumptions:
598 cb58f329 2020-01-15 crossd * Chars are 8 bits long.
599 cb58f329 2020-01-15 crossd * Algorithm:
600 cb58f329 2020-01-15 crossd * Maintain a BITS character long buffer (so that 8 codes will
601 cb58f329 2020-01-15 crossd * fit in it exactly). When the buffer fills up empty it and start over.
604 cb58f329 2020-01-15 crossd static char buf[BITS];
606 cb58f329 2020-01-15 crossd uchar lmask[9] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00};
607 cb58f329 2020-01-15 crossd uchar rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
610 cb58f329 2020-01-15 crossd output( code )
611 cb58f329 2020-01-15 crossd code_int code;
613 cb58f329 2020-01-15 crossd #ifdef DEBUG
614 cb58f329 2020-01-15 crossd static int col = 0;
616 cb58f329 2020-01-15 crossd int r_off = offset, bits= n_bits;
617 cb58f329 2020-01-15 crossd char *bp = buf;
619 cb58f329 2020-01-15 crossd #ifdef DEBUG
620 cb58f329 2020-01-15 crossd if (verbose)
621 cb58f329 2020-01-15 crossd fprintf(stderr, "%5d%c", code,
622 cb58f329 2020-01-15 crossd (col+=6) >= 74? (col = 0, '\n'): ' ');
624 cb58f329 2020-01-15 crossd if (code >= 0) {
626 cb58f329 2020-01-15 crossd * byte/bit numbering on the VAX is simulated by the
627 cb58f329 2020-01-15 crossd * following code
630 cb58f329 2020-01-15 crossd * Get to the first byte.
632 cb58f329 2020-01-15 crossd bp += (r_off >> 3);
633 cb58f329 2020-01-15 crossd r_off &= 7;
635 cb58f329 2020-01-15 crossd * Since code is always >= 8 bits, only need to mask the first
636 cb58f329 2020-01-15 crossd * hunk on the left.
638 cb58f329 2020-01-15 crossd *bp = (*bp & rmask[r_off]) | (code << r_off) & lmask[r_off];
640 cb58f329 2020-01-15 crossd bits -= 8 - r_off;
641 cb58f329 2020-01-15 crossd code >>= 8 - r_off;
642 cb58f329 2020-01-15 crossd /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
643 cb58f329 2020-01-15 crossd if ( bits >= 8 ) {
644 cb58f329 2020-01-15 crossd *bp++ = code;
645 cb58f329 2020-01-15 crossd code >>= 8;
646 cb58f329 2020-01-15 crossd bits -= 8;
648 cb58f329 2020-01-15 crossd /* Last bits. */
650 cb58f329 2020-01-15 crossd *bp = code;
652 cb58f329 2020-01-15 crossd offset += n_bits;
653 cb58f329 2020-01-15 crossd if ( offset == (n_bits << 3) ) {
654 cb58f329 2020-01-15 crossd bp = buf;
655 cb58f329 2020-01-15 crossd bits = n_bits;
656 cb58f329 2020-01-15 crossd bytes_out += bits;
658 cb58f329 2020-01-15 crossd putchar(*bp++);
659 cb58f329 2020-01-15 crossd } while(--bits);
660 cb58f329 2020-01-15 crossd offset = 0;
664 cb58f329 2020-01-15 crossd * If the next entry is going to be too big for the code size,
665 cb58f329 2020-01-15 crossd * then increase it, if possible.
667 cb58f329 2020-01-15 crossd if ( free_ent > maxcode || (clear_flg > 0)) {
669 cb58f329 2020-01-15 crossd * Write the whole buffer, because the input side won't
670 cb58f329 2020-01-15 crossd * discover the size increase until after it has read it.
672 cb58f329 2020-01-15 crossd if ( offset > 0 ) {
673 cb58f329 2020-01-15 crossd if( fwrite( buf, 1, n_bits, stdout ) != n_bits)
674 cb58f329 2020-01-15 crossd writeerr();
675 cb58f329 2020-01-15 crossd bytes_out += n_bits;
677 cb58f329 2020-01-15 crossd offset = 0;
679 cb58f329 2020-01-15 crossd if ( clear_flg ) {
680 cb58f329 2020-01-15 crossd maxcode = MAXCODE (n_bits = INIT_BITS);
681 cb58f329 2020-01-15 crossd clear_flg = 0;
683 cb58f329 2020-01-15 crossd n_bits++;
684 cb58f329 2020-01-15 crossd if ( n_bits == maxbits )
685 cb58f329 2020-01-15 crossd maxcode = maxmaxcode;
687 cb58f329 2020-01-15 crossd maxcode = MAXCODE(n_bits);
689 cb58f329 2020-01-15 crossd #ifdef DEBUG
690 cb58f329 2020-01-15 crossd if ( debug ) {
691 cb58f329 2020-01-15 crossd fprintf(stderr,
692 cb58f329 2020-01-15 crossd "\nChange to %d bits\n", n_bits);
699 cb58f329 2020-01-15 crossd * At EOF, write the rest of the buffer.
701 cb58f329 2020-01-15 crossd if ( offset > 0 )
702 cb58f329 2020-01-15 crossd fwrite( buf, 1, (offset + 7) / 8, stdout );
703 cb58f329 2020-01-15 crossd bytes_out += (offset + 7) / 8;
704 cb58f329 2020-01-15 crossd offset = 0;
705 cb58f329 2020-01-15 crossd fflush( stdout );
706 cb58f329 2020-01-15 crossd #ifdef DEBUG
707 cb58f329 2020-01-15 crossd if ( verbose )
708 cb58f329 2020-01-15 crossd fprintf( stderr, "\n" );
710 cb58f329 2020-01-15 crossd if( ferror( stdout ) )
711 cb58f329 2020-01-15 crossd writeerr();
716 cb58f329 2020-01-15 crossd * Decompress stdin to stdout. This routine adapts to the codes in the
717 cb58f329 2020-01-15 crossd * file building the "string" table on-the-fly; requiring no table to
718 cb58f329 2020-01-15 crossd * be stored in the compressed file. The tables used herein are shared
719 cb58f329 2020-01-15 crossd * with those of the compress() routine. See the definitions above.
722 cb58f329 2020-01-15 crossd decompress(void)
724 cb58f329 2020-01-15 crossd int finchar;
725 cb58f329 2020-01-15 crossd code_int code, oldcode, incode;
726 cb58f329 2020-01-15 crossd uchar *stackp;
729 cb58f329 2020-01-15 crossd * As above, initialize the first 256 entries in the table.
731 cb58f329 2020-01-15 crossd maxcode = MAXCODE(n_bits = INIT_BITS);
732 cb58f329 2020-01-15 crossd for (code = 255; code >= 0; code--) {
733 cb58f329 2020-01-15 crossd tab_prefixof(code) = 0;
734 cb58f329 2020-01-15 crossd tab_suffixof(code) = (uchar)code;
736 cb58f329 2020-01-15 crossd free_ent = (block_compress? FIRST: 256);
738 cb58f329 2020-01-15 crossd finchar = oldcode = getcode();
739 cb58f329 2020-01-15 crossd if(oldcode == -1) /* EOF already? */
740 cb58f329 2020-01-15 crossd return; /* Get out of here */
741 cb58f329 2020-01-15 crossd putchar((char)finchar); /* first code must be 8 bits = char */
742 cb58f329 2020-01-15 crossd if(ferror(stdout)) /* Crash if can't write */
743 cb58f329 2020-01-15 crossd writeerr();
744 cb58f329 2020-01-15 crossd stackp = de_stack;
746 cb58f329 2020-01-15 crossd while ((code = getcode()) > -1) {
747 cb58f329 2020-01-15 crossd if ((code == CLEAR) && block_compress) {
748 cb58f329 2020-01-15 crossd for (code = 255; code >= 0; code--)
749 cb58f329 2020-01-15 crossd tab_prefixof(code) = 0;
750 cb58f329 2020-01-15 crossd clear_flg = 1;
751 cb58f329 2020-01-15 crossd free_ent = FIRST - 1;
752 cb58f329 2020-01-15 crossd if ((code = getcode()) == -1) /* O, untimely death! */
755 cb58f329 2020-01-15 crossd incode = code;
757 cb58f329 2020-01-15 crossd * Special case for KwKwK string.
759 cb58f329 2020-01-15 crossd if (code >= free_ent) {
760 cb58f329 2020-01-15 crossd *stackp++ = finchar;
761 cb58f329 2020-01-15 crossd code = oldcode;
765 cb58f329 2020-01-15 crossd * Generate output characters in reverse order
767 cb58f329 2020-01-15 crossd while (code >= 256) {
768 cb58f329 2020-01-15 crossd *stackp++ = tab_suffixof(code);
769 cb58f329 2020-01-15 crossd code = tab_prefixof(code);
771 cb58f329 2020-01-15 crossd *stackp++ = finchar = tab_suffixof(code);
774 cb58f329 2020-01-15 crossd * And put them out in forward order
777 cb58f329 2020-01-15 crossd putchar(*--stackp);
778 cb58f329 2020-01-15 crossd } while (stackp > de_stack);
781 cb58f329 2020-01-15 crossd * Generate the new entry.
783 cb58f329 2020-01-15 crossd if ( (code=free_ent) < maxmaxcode ) {
784 cb58f329 2020-01-15 crossd tab_prefixof(code) = (ushort)oldcode;
785 cb58f329 2020-01-15 crossd tab_suffixof(code) = finchar;
786 cb58f329 2020-01-15 crossd free_ent = code+1;
789 cb58f329 2020-01-15 crossd * Remember previous code.
791 cb58f329 2020-01-15 crossd oldcode = incode;
793 cb58f329 2020-01-15 crossd fflush(stdout);
794 cb58f329 2020-01-15 crossd if(ferror(stdout))
795 cb58f329 2020-01-15 crossd writeerr();
799 cb58f329 2020-01-15 crossd * TAG( getcode )
801 cb58f329 2020-01-15 crossd * Read one code from the standard input. If EOF, return -1.
802 cb58f329 2020-01-15 crossd * Inputs:
804 cb58f329 2020-01-15 crossd * Outputs:
805 cb58f329 2020-01-15 crossd * code or -1 is returned.
808 cb58f329 2020-01-15 crossd getcode()
810 cb58f329 2020-01-15 crossd int r_off, bits;
811 cb58f329 2020-01-15 crossd code_int code;
812 cb58f329 2020-01-15 crossd static int offset = 0, size = 0;
813 cb58f329 2020-01-15 crossd static uchar buf[BITS];
814 cb58f329 2020-01-15 crossd uchar *bp = buf;
816 cb58f329 2020-01-15 crossd if ( clear_flg > 0 || offset >= size || free_ent > maxcode ) {
818 cb58f329 2020-01-15 crossd * If the next entry will be too big for the current code
819 cb58f329 2020-01-15 crossd * size, then we must increase the size. This implies reading
820 cb58f329 2020-01-15 crossd * a new buffer full, too.
822 cb58f329 2020-01-15 crossd if ( free_ent > maxcode ) {
823 cb58f329 2020-01-15 crossd n_bits++;
824 cb58f329 2020-01-15 crossd if ( n_bits == maxbits )
825 cb58f329 2020-01-15 crossd maxcode = maxmaxcode; /* won't get any bigger now */
827 cb58f329 2020-01-15 crossd maxcode = MAXCODE(n_bits);
829 cb58f329 2020-01-15 crossd if ( clear_flg > 0) {
830 cb58f329 2020-01-15 crossd maxcode = MAXCODE(n_bits = INIT_BITS);
831 cb58f329 2020-01-15 crossd clear_flg = 0;
833 cb58f329 2020-01-15 crossd size = fread(buf, 1, n_bits, stdin);
834 cb58f329 2020-01-15 crossd if (size <= 0)
835 cb58f329 2020-01-15 crossd return -1; /* end of file */
836 cb58f329 2020-01-15 crossd offset = 0;
837 cb58f329 2020-01-15 crossd /* Round size down to integral number of codes */
838 cb58f329 2020-01-15 crossd size = (size << 3) - (n_bits - 1);
840 cb58f329 2020-01-15 crossd r_off = offset;
841 cb58f329 2020-01-15 crossd bits = n_bits;
843 cb58f329 2020-01-15 crossd * Get to the first byte.
845 cb58f329 2020-01-15 crossd bp += (r_off >> 3);
846 cb58f329 2020-01-15 crossd r_off &= 7;
847 cb58f329 2020-01-15 crossd /* Get first part (low order bits) */
848 cb58f329 2020-01-15 crossd code = (*bp++ >> r_off);
849 cb58f329 2020-01-15 crossd bits -= (8 - r_off);
850 cb58f329 2020-01-15 crossd r_off = 8 - r_off; /* now, offset into code word */
851 cb58f329 2020-01-15 crossd /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
852 cb58f329 2020-01-15 crossd if (bits >= 8) {
853 cb58f329 2020-01-15 crossd code |= *bp++ << r_off;
854 cb58f329 2020-01-15 crossd r_off += 8;
855 cb58f329 2020-01-15 crossd bits -= 8;
857 cb58f329 2020-01-15 crossd /* high order bits. */
858 cb58f329 2020-01-15 crossd code |= (*bp & rmask[bits]) << r_off;
859 cb58f329 2020-01-15 crossd offset += n_bits;
860 cb58f329 2020-01-15 crossd return code;
863 cb58f329 2020-01-15 crossd #ifdef DEBUG
864 cb58f329 2020-01-15 crossd printcodes()
867 cb58f329 2020-01-15 crossd * Just print out codes from input file. For debugging.
869 cb58f329 2020-01-15 crossd code_int code;
870 cb58f329 2020-01-15 crossd int col = 0, bits;
872 cb58f329 2020-01-15 crossd bits = n_bits = INIT_BITS;
873 cb58f329 2020-01-15 crossd maxcode = MAXCODE(n_bits);
874 cb58f329 2020-01-15 crossd free_ent = ((block_compress) ? FIRST : 256 );
875 cb58f329 2020-01-15 crossd while ( ( code = getcode() ) >= 0 ) {
876 cb58f329 2020-01-15 crossd if ( (code == CLEAR) && block_compress ) {
877 cb58f329 2020-01-15 crossd free_ent = FIRST - 1;
878 cb58f329 2020-01-15 crossd clear_flg = 1;
880 cb58f329 2020-01-15 crossd else if ( free_ent < maxmaxcode )
881 cb58f329 2020-01-15 crossd free_ent++;
882 cb58f329 2020-01-15 crossd if ( bits != n_bits ) {
883 cb58f329 2020-01-15 crossd fprintf(stderr, "\nChange to %d bits\n", n_bits );
884 cb58f329 2020-01-15 crossd bits = n_bits;
887 cb58f329 2020-01-15 crossd fprintf(stderr, "%5d%c", code, (col+=6) >= 74 ? (col = 0, '\n') : ' ' );
889 cb58f329 2020-01-15 crossd putc( '\n', stderr );
890 cb58f329 2020-01-15 crossd exit( 0 );
893 cb58f329 2020-01-15 crossd code_int sorttab[1<<BITS]; /* sorted pointers into htab */
895 cb58f329 2020-01-15 crossd #define STACK_SIZE 15000
897 cb58f329 2020-01-15 crossd dump_tab() /* dump string table */
899 cb58f329 2020-01-15 crossd int i, first, c, ent;
900 cb58f329 2020-01-15 crossd int stack_top = STACK_SIZE;
902 cb58f329 2020-01-15 crossd if(do_decomp == 0) { /* compressing */
903 cb58f329 2020-01-15 crossd int flag = 1;
905 cb58f329 2020-01-15 crossd for(i=0; i<hsize; i++) { /* build sort pointers */
906 cb58f329 2020-01-15 crossd if((long)htabof(i) >= 0) {
907 cb58f329 2020-01-15 crossd sorttab[codetabof(i)] = i;
910 cb58f329 2020-01-15 crossd first = block_compress ? FIRST : 256;
911 cb58f329 2020-01-15 crossd for(i = first; i < free_ent; i++) {
912 cb58f329 2020-01-15 crossd fprintf(stderr, "%5d: \"", i);
913 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '\n';
914 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '"';
915 cb58f329 2020-01-15 crossd stack_top = in_stack((htabof(sorttab[i])>>maxbits)&0xff,
916 cb58f329 2020-01-15 crossd stack_top);
917 cb58f329 2020-01-15 crossd for(ent=htabof(sorttab[i]) & ((1<<maxbits)-1);
918 cb58f329 2020-01-15 crossd ent > 256;
919 cb58f329 2020-01-15 crossd ent=htabof(sorttab[ent]) & ((1<<maxbits)-1)) {
920 cb58f329 2020-01-15 crossd stack_top = in_stack(htabof(sorttab[ent]) >> maxbits,
921 cb58f329 2020-01-15 crossd stack_top);
923 cb58f329 2020-01-15 crossd stack_top = in_stack(ent, stack_top);
924 cb58f329 2020-01-15 crossd fwrite( &de_stack[stack_top], 1, STACK_SIZE-stack_top, stderr);
925 cb58f329 2020-01-15 crossd stack_top = STACK_SIZE;
927 cb58f329 2020-01-15 crossd } else if(!debug) { /* decompressing */
929 cb58f329 2020-01-15 crossd for ( i = 0; i < free_ent; i++ ) {
931 cb58f329 2020-01-15 crossd c = tab_suffixof(ent);
932 cb58f329 2020-01-15 crossd if ( isascii(c) && isprint(c) )
933 cb58f329 2020-01-15 crossd fprintf( stderr, "%5d: %5d/'%c' \"",
934 cb58f329 2020-01-15 crossd ent, tab_prefixof(ent), c );
936 cb58f329 2020-01-15 crossd fprintf( stderr, "%5d: %5d/\\%03o \"",
937 cb58f329 2020-01-15 crossd ent, tab_prefixof(ent), c );
938 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '\n';
939 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '"';
940 cb58f329 2020-01-15 crossd for ( ; ent != NULL;
941 cb58f329 2020-01-15 crossd ent = (ent >= FIRST ? tab_prefixof(ent) : NULL) ) {
942 cb58f329 2020-01-15 crossd stack_top = in_stack(tab_suffixof(ent), stack_top);
944 cb58f329 2020-01-15 crossd fwrite( &de_stack[stack_top], 1, STACK_SIZE - stack_top, stderr );
945 cb58f329 2020-01-15 crossd stack_top = STACK_SIZE;
951 cb58f329 2020-01-15 crossd in_stack(int c, int stack_top)
953 cb58f329 2020-01-15 crossd if ( (isascii(c) && isprint(c) && c != '\\') || c == ' ' ) {
954 cb58f329 2020-01-15 crossd de_stack[--stack_top] = c;
956 cb58f329 2020-01-15 crossd switch( c ) {
957 cb58f329 2020-01-15 crossd case '\n': de_stack[--stack_top] = 'n'; break;
958 cb58f329 2020-01-15 crossd case '\t': de_stack[--stack_top] = 't'; break;
959 cb58f329 2020-01-15 crossd case '\b': de_stack[--stack_top] = 'b'; break;
960 cb58f329 2020-01-15 crossd case '\f': de_stack[--stack_top] = 'f'; break;
961 cb58f329 2020-01-15 crossd case '\r': de_stack[--stack_top] = 'r'; break;
962 cb58f329 2020-01-15 crossd case '\\': de_stack[--stack_top] = '\\'; break;
964 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '0' + c % 8;
965 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '0' + (c / 8) % 8;
966 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '0' + c / 64;
969 cb58f329 2020-01-15 crossd de_stack[--stack_top] = '\\';
971 cb58f329 2020-01-15 crossd return stack_top;
973 cb58f329 2020-01-15 crossd #endif /* DEBUG */
976 cb58f329 2020-01-15 crossd writeerr(void)
978 cb58f329 2020-01-15 crossd perror(ofname);
979 cb58f329 2020-01-15 crossd unlink(ofname);
984 cb58f329 2020-01-15 crossd copystat(ifname, ofname)
985 cb58f329 2020-01-15 crossd char *ifname, *ofname;
987 cb58f329 2020-01-15 crossd int mode;
988 cb58f329 2020-01-15 crossd time_t timep[2]; /* should be struct utimbuf */
989 cb58f329 2020-01-15 crossd struct stat statbuf;
991 cb58f329 2020-01-15 crossd fclose(stdout);
992 cb58f329 2020-01-15 crossd if (stat(ifname, &statbuf)) { /* Get stat on input file */
993 cb58f329 2020-01-15 crossd perror(ifname);
996 cb58f329 2020-01-15 crossd if (!S_ISREG(statbuf.st_mode)) {
997 cb58f329 2020-01-15 crossd if (quiet)
998 cb58f329 2020-01-15 crossd fprintf(stderr, "%s: ", ifname);
999 cb58f329 2020-01-15 crossd fprintf(stderr, " -- not a regular file: unchanged");
1000 cb58f329 2020-01-15 crossd exit_stat = 1;
1001 cb58f329 2020-01-15 crossd } else if (exit_stat == 2 && !force) {
1002 cb58f329 2020-01-15 crossd /* No compression: remove file.Z */
1003 cb58f329 2020-01-15 crossd if (!quiet)
1004 cb58f329 2020-01-15 crossd fprintf(stderr, " -- file unchanged");
1005 cb58f329 2020-01-15 crossd } else { /* Successful Compression */
1006 cb58f329 2020-01-15 crossd exit_stat = 0;
1007 cb58f329 2020-01-15 crossd mode = statbuf.st_mode & 0777;
1008 cb58f329 2020-01-15 crossd if (chmod(ofname, mode)) /* Copy modes */
1009 cb58f329 2020-01-15 crossd perror(ofname);
1010 cb58f329 2020-01-15 crossd /* Copy ownership */
1011 cb58f329 2020-01-15 crossd chown(ofname, statbuf.st_uid, statbuf.st_gid);
1012 cb58f329 2020-01-15 crossd timep[0] = statbuf.st_atime;
1013 cb58f329 2020-01-15 crossd timep[1] = statbuf.st_mtime;
1014 cb58f329 2020-01-15 crossd /* Update last accessed and modified times */
1015 cb58f329 2020-01-15 crossd utime(ofname, (struct utimbuf *)timep);
1016 cb58f329 2020-01-15 crossd // if (unlink(ifname)) /* Remove input file */
1017 cb58f329 2020-01-15 crossd // perror(ifname);
1018 cb58f329 2020-01-15 crossd return; /* success */
1021 cb58f329 2020-01-15 crossd /* Unsuccessful return -- one of the tests failed */
1022 cb58f329 2020-01-15 crossd if (unlink(ofname))
1023 cb58f329 2020-01-15 crossd perror(ofname);
1027 cb58f329 2020-01-15 crossd * This routine returns 1 if we are running in the foreground and stderr
1028 cb58f329 2020-01-15 crossd * is a tty.
1031 cb58f329 2020-01-15 crossd foreground(void)
1033 cb58f329 2020-01-15 crossd if(bgnd_flag) /* background? */
1034 cb58f329 2020-01-15 crossd return 0;
1035 cb58f329 2020-01-15 crossd else /* foreground */
1036 cb58f329 2020-01-15 crossd return isatty(2); /* and stderr is a tty */
1040 cb58f329 2020-01-15 crossd onintr(int x)
1042 cb58f329 2020-01-15 crossd USED(x);
1043 cb58f329 2020-01-15 crossd unlink(ofname);
1044 cb58f329 2020-01-15 crossd exit(1);
1048 cb58f329 2020-01-15 crossd oops(int x) /* wild pointer -- assume bad input */
1050 cb58f329 2020-01-15 crossd USED(x);
1051 cb58f329 2020-01-15 crossd if (do_decomp == 1)
1052 cb58f329 2020-01-15 crossd fprintf(stderr, "uncompress: corrupt input\n");
1053 cb58f329 2020-01-15 crossd unlink(ofname);
1054 cb58f329 2020-01-15 crossd exit(1);
1058 cb58f329 2020-01-15 crossd cl_block(void) /* table clear for block compress */
1060 cb58f329 2020-01-15 crossd long rat;
1062 cb58f329 2020-01-15 crossd checkpoint = in_count + CHECK_GAP;
1063 cb58f329 2020-01-15 crossd #ifdef DEBUG
1064 cb58f329 2020-01-15 crossd if ( debug ) {
1065 cb58f329 2020-01-15 crossd fprintf ( stderr, "count: %ld, ratio: ", in_count );
1066 cb58f329 2020-01-15 crossd prratio ( stderr, in_count, bytes_out );
1067 cb58f329 2020-01-15 crossd fprintf ( stderr, "\n");
1069 cb58f329 2020-01-15 crossd #endif /* DEBUG */
1071 cb58f329 2020-01-15 crossd if (in_count > 0x007fffff) { /* shift will overflow */
1072 cb58f329 2020-01-15 crossd rat = bytes_out >> 8;
1073 cb58f329 2020-01-15 crossd if (rat == 0) /* Don't divide by zero */
1074 cb58f329 2020-01-15 crossd rat = 0x7fffffff;
1076 cb58f329 2020-01-15 crossd rat = in_count / rat;
1078 cb58f329 2020-01-15 crossd rat = (in_count << 8) / bytes_out; /* 8 fractional bits */
1079 cb58f329 2020-01-15 crossd if (rat > ratio)
1080 cb58f329 2020-01-15 crossd ratio = rat;
1082 cb58f329 2020-01-15 crossd ratio = 0;
1083 cb58f329 2020-01-15 crossd #ifdef DEBUG
1084 cb58f329 2020-01-15 crossd if (verbose)
1085 cb58f329 2020-01-15 crossd dump_tab(); /* dump string table */
1087 cb58f329 2020-01-15 crossd cl_hash((count_int)hsize);
1088 cb58f329 2020-01-15 crossd free_ent = FIRST;
1089 cb58f329 2020-01-15 crossd clear_flg = 1;
1090 cb58f329 2020-01-15 crossd output((code_int)CLEAR);
1091 cb58f329 2020-01-15 crossd #ifdef DEBUG
1092 cb58f329 2020-01-15 crossd if (debug)
1093 cb58f329 2020-01-15 crossd fprintf(stderr, "clear\n");
1094 cb58f329 2020-01-15 crossd #endif /* DEBUG */
1099 cb58f329 2020-01-15 crossd cl_hash(count_int hsize) /* reset code table */
1101 cb58f329 2020-01-15 crossd count_int *htab_p = htab+hsize;
1103 cb58f329 2020-01-15 crossd long m1 = -1;
1105 cb58f329 2020-01-15 crossd i = hsize - 16;
1106 cb58f329 2020-01-15 crossd do { /* might use Sys V memset(3) here */
1107 cb58f329 2020-01-15 crossd *(htab_p-16) = m1;
1108 cb58f329 2020-01-15 crossd *(htab_p-15) = m1;
1109 cb58f329 2020-01-15 crossd *(htab_p-14) = m1;
1110 cb58f329 2020-01-15 crossd *(htab_p-13) = m1;
1111 cb58f329 2020-01-15 crossd *(htab_p-12) = m1;
1112 cb58f329 2020-01-15 crossd *(htab_p-11) = m1;
1113 cb58f329 2020-01-15 crossd *(htab_p-10) = m1;
1114 cb58f329 2020-01-15 crossd *(htab_p-9) = m1;
1115 cb58f329 2020-01-15 crossd *(htab_p-8) = m1;
1116 cb58f329 2020-01-15 crossd *(htab_p-7) = m1;
1117 cb58f329 2020-01-15 crossd *(htab_p-6) = m1;
1118 cb58f329 2020-01-15 crossd *(htab_p-5) = m1;
1119 cb58f329 2020-01-15 crossd *(htab_p-4) = m1;
1120 cb58f329 2020-01-15 crossd *(htab_p-3) = m1;
1121 cb58f329 2020-01-15 crossd *(htab_p-2) = m1;
1122 cb58f329 2020-01-15 crossd *(htab_p-1) = m1;
1123 cb58f329 2020-01-15 crossd htab_p -= 16;
1124 cb58f329 2020-01-15 crossd } while ((i -= 16) >= 0);
1125 cb58f329 2020-01-15 crossd for ( i += 16; i > 0; i-- )
1126 cb58f329 2020-01-15 crossd *--htab_p = m1;
1130 cb58f329 2020-01-15 crossd prratio(stream, num, den)
1131 cb58f329 2020-01-15 crossd FILE *stream;
1132 cb58f329 2020-01-15 crossd long num, den;
1134 cb58f329 2020-01-15 crossd int q; /* Doesn't need to be long */
1136 cb58f329 2020-01-15 crossd if(num > 214748L) /* 2147483647/10000 */
1137 cb58f329 2020-01-15 crossd q = num / (den / 10000L);
1139 cb58f329 2020-01-15 crossd q = 10000L * num / den; /* Long calculations, though */
1140 cb58f329 2020-01-15 crossd if (q < 0) {
1141 cb58f329 2020-01-15 crossd putc('-', stream);
1144 cb58f329 2020-01-15 crossd fprintf(stream, "%d.%02d%%", q / 100, q % 100);
1148 cb58f329 2020-01-15 crossd version(void)
1150 cb58f329 2020-01-15 crossd fprintf(stderr, "%s\n", rcs_ident);
1151 cb58f329 2020-01-15 crossd fprintf(stderr, "Options: ");
1152 cb58f329 2020-01-15 crossd #ifdef DEBUG
1153 cb58f329 2020-01-15 crossd fprintf(stderr, "DEBUG, ");
1155 cb58f329 2020-01-15 crossd #ifdef BSD4_2
1156 cb58f329 2020-01-15 crossd fprintf(stderr, "BSD4_2, ");
1158 cb58f329 2020-01-15 crossd fprintf(stderr, "BITS = %d\n", BITS);
1162 cb58f329 2020-01-15 crossd * The revision-history novel:
1164 cb58f329 2020-01-15 crossd * $Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $
1165 cb58f329 2020-01-15 crossd * $Log: compress.c,v $
1166 cb58f329 2020-01-15 crossd * Revision 4.0 85/07/30 12:50:00 joe
1167 cb58f329 2020-01-15 crossd * Removed ferror() calls in output routine on every output except first.
1168 cb58f329 2020-01-15 crossd * Prepared for release to the world.
1170 cb58f329 2020-01-15 crossd * Revision 3.6 85/07/04 01:22:21 joe
1171 cb58f329 2020-01-15 crossd * Remove much wasted storage by overlaying hash table with the tables
1172 cb58f329 2020-01-15 crossd * used by decompress: tab_suffix[1<<BITS], stack[8000]. Updated USERMEM
1173 cb58f329 2020-01-15 crossd * computations. Fixed dump_tab() DEBUG routine.
1175 cb58f329 2020-01-15 crossd * Revision 3.5 85/06/30 20:47:21 jaw
1176 cb58f329 2020-01-15 crossd * Change hash function to use exclusive-or. Rip out hash cache. These
1177 cb58f329 2020-01-15 crossd * speedups render the megamemory version defunct, for now. Make decoder
1178 cb58f329 2020-01-15 crossd * stack global. Parts of the RCS trunks 2.7, 2.6, and 2.1 no longer apply.
1180 cb58f329 2020-01-15 crossd * Revision 3.4 85/06/27 12:00:00 ken
1181 cb58f329 2020-01-15 crossd * Get rid of all floating-point calculations by doing all compression ratio
1182 cb58f329 2020-01-15 crossd * calculations in fixed point.
1184 cb58f329 2020-01-15 crossd * Revision 3.3 85/06/24 21:53:24 joe
1185 cb58f329 2020-01-15 crossd * Incorporate portability suggestion for M_XENIX. Got rid of text on #else
1186 cb58f329 2020-01-15 crossd * and #endif lines. Cleaned up #ifdefs for vax and interdata.
1188 cb58f329 2020-01-15 crossd * Revision 3.2 85/06/06 21:53:24 jaw
1189 cb58f329 2020-01-15 crossd * Incorporate portability suggestions for Z8000, IBM PC/XT from mailing list.
1190 cb58f329 2020-01-15 crossd * Default to "quiet" output (no compression statistics).
1192 cb58f329 2020-01-15 crossd * Revision 3.1 85/05/12 18:56:13 jaw
1193 cb58f329 2020-01-15 crossd * Integrate decompress() stack speedups (from early pointer mods by McKie).
1194 cb58f329 2020-01-15 crossd * Repair multi-file USERMEM gaffe. Unify 'force' flags to mimic semantics
1195 cb58f329 2020-01-15 crossd * of SVR2 'pack'. Streamline block-compress table clear logic. Increase
1196 cb58f329 2020-01-15 crossd * output byte count by magic number size.
1198 cb58f329 2020-01-15 crossd * Revision 3.0 84/11/27 11:50:00 petsd!joe
1199 cb58f329 2020-01-15 crossd * Set HSIZE depending on BITS. Set BITS depending on USERMEM. Unrolled
1200 cb58f329 2020-01-15 crossd * loops in clear routines. Added "-C" flag for 2.0 compatibility. Used
1201 cb58f329 2020-01-15 crossd * unsigned compares on Perkin-Elmer. Fixed foreground check.
1203 cb58f329 2020-01-15 crossd * Revision 2.7 84/11/16 19:35:39 ames!jaw
1204 cb58f329 2020-01-15 crossd * Cache common hash codes based on input statistics; this improves
1205 cb58f329 2020-01-15 crossd * performance for low-density raster images. Pass on #ifdef bundle
1206 cb58f329 2020-01-15 crossd * from Turkowski.
1208 cb58f329 2020-01-15 crossd * Revision 2.6 84/11/05 19:18:21 ames!jaw
1209 cb58f329 2020-01-15 crossd * Vary size of hash tables to reduce time for small files.
1210 cb58f329 2020-01-15 crossd * Tune PDP-11 hash function.
1212 cb58f329 2020-01-15 crossd * Revision 2.5 84/10/30 20:15:14 ames!jaw
1213 cb58f329 2020-01-15 crossd * Junk chaining; replace with the simpler (and, on the VAX, faster)
1214 cb58f329 2020-01-15 crossd * double hashing, discussed within. Make block compression standard.
1216 cb58f329 2020-01-15 crossd * Revision 2.4 84/10/16 11:11:11 ames!jaw
1217 cb58f329 2020-01-15 crossd * Introduce adaptive reset for block compression, to boost the rate
1218 cb58f329 2020-01-15 crossd * another several percent. (See mailing list notes.)
1220 cb58f329 2020-01-15 crossd * Revision 2.3 84/09/22 22:00:00 petsd!joe
1221 cb58f329 2020-01-15 crossd * Implemented "-B" block compress. Implemented REVERSE sorting of tab_next.
1222 cb58f329 2020-01-15 crossd * Bug fix for last bits. Changed fwrite to putchar loop everywhere.
1224 cb58f329 2020-01-15 crossd * Revision 2.2 84/09/18 14:12:21 ames!jaw
1225 cb58f329 2020-01-15 crossd * Fold in news changes, small machine typedef from thomas,
1226 cb58f329 2020-01-15 crossd * #ifdef interdata from joe.
1228 cb58f329 2020-01-15 crossd * Revision 2.1 84/09/10 12:34:56 ames!jaw
1229 cb58f329 2020-01-15 crossd * Configured fast table lookup for 32-bit machines.
1230 cb58f329 2020-01-15 crossd * This cuts user time in half for b <= FBITS, and is useful for news batching
1231 cb58f329 2020-01-15 crossd * from VAX to PDP sites. Also sped up decompress() [fwrite->putc] and
1232 cb58f329 2020-01-15 crossd * added signal catcher [plus beef in writeerr()] to delete effluvia.
1234 cb58f329 2020-01-15 crossd * Revision 2.0 84/08/28 22:00:00 petsd!joe
1235 cb58f329 2020-01-15 crossd * Add check for foreground before prompting user. Insert maxbits into
1236 cb58f329 2020-01-15 crossd * compressed file. Force file being uncompressed to end with ".Z".
1237 cb58f329 2020-01-15 crossd * Added "-c" flag and "zcat". Prepared for release.
1239 cb58f329 2020-01-15 crossd * Revision 1.10 84/08/24 18:28:00 turtlevax!ken
1240 cb58f329 2020-01-15 crossd * Will only compress regular files (no directories), added a magic number
1241 cb58f329 2020-01-15 crossd * header (plus an undocumented -n flag to handle old files without headers),
1242 cb58f329 2020-01-15 crossd * added -f flag to force overwriting of possibly existing destination file,
1243 cb58f329 2020-01-15 crossd * otherwise the user is prompted for a response. Will tack on a .Z to a
1244 cb58f329 2020-01-15 crossd * filename if it doesn't have one when decompressing. Will only replace
1245 cb58f329 2020-01-15 crossd * file if it was compressed.
1247 cb58f329 2020-01-15 crossd * Revision 1.9 84/08/16 17:28:00 turtlevax!ken
1248 cb58f329 2020-01-15 crossd * Removed scanargs(), getopt(), added .Z extension and unlimited number of
1249 cb58f329 2020-01-15 crossd * filenames to compress. Flags may be clustered (-Ddvb12) or separated
1250 cb58f329 2020-01-15 crossd * (-D -d -v -b 12), or combination thereof. Modes and other status is
1251 cb58f329 2020-01-15 crossd * copied with copystat(). -O bug for 4.2 seems to have disappeared with
1254 cb58f329 2020-01-15 crossd * Revision 1.8 84/08/09 23:15:00 joe
1255 cb58f329 2020-01-15 crossd * Made it compatible with vax version, installed jim's fixes/enhancements
1257 cb58f329 2020-01-15 crossd * Revision 1.6 84/08/01 22:08:00 joe
1258 cb58f329 2020-01-15 crossd * Sped up algorithm significantly by sorting the compress chain.
1260 cb58f329 2020-01-15 crossd * Revision 1.5 84/07/13 13:11:00 srd
1261 cb58f329 2020-01-15 crossd * Added C version of vax asm routines. Changed structure to arrays to
1262 cb58f329 2020-01-15 crossd * save much memory. Do unsigned compares where possible (faster on
1263 cb58f329 2020-01-15 crossd * Perkin-Elmer)
1265 cb58f329 2020-01-15 crossd * Revision 1.4 84/07/05 03:11:11 thomas
1266 cb58f329 2020-01-15 crossd * Clean up the code a little and lint it. (Lint complains about all
1267 cb58f329 2020-01-15 crossd * the regs used in the asm, but I'm not going to "fix" this.)
1269 cb58f329 2020-01-15 crossd * Revision 1.3 84/07/05 02:06:54 thomas
1270 cb58f329 2020-01-15 crossd * Minor fixes.
1272 cb58f329 2020-01-15 crossd * Revision 1.2 84/07/05 00:27:27 thomas
1273 cb58f329 2020-01-15 crossd * Add variable bit length output.
