xref: /titanic_51/usr/src/cmd/pack/pack.c (revision 8eea8e29cc4374d1ee24c25a07f45af132db3499)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 /*
34  *	Huffman encoding program
35  *	Usage:	pack [[ -f ] [ - ] filename ... ] filename ...
36  *		- option: enable/disable listing of statistics
37  */
38 
39 #include <stdio.h>
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 #include <unistd.h>
43 #include <locale.h>
44 #include <stdarg.h>
45 #include <errno.h>
46 #include <sys/isa_defs.h>
47 #include <stdlib.h>
48 #include <limits.h>
49 #include <sys/param.h>
50 #include <fcntl.h>
51 #include <utime.h>
52 #include <string.h>
53 #include <dirent.h>
54 #include <unistd.h>
55 
56 #undef lint
57 
58 #define	END	256
59 #define	PACKED 017436 /* <US><RS> - Unlikely value */
60 #define	SUF0	'.'
61 #define	SUF1	'z'
62 
63 struct stat status, ostatus;
64 static struct utimbuf u_times;
65 
66 /* union for overlaying a long int with a set of four characters */
67 union FOUR {
68 	struct { long int lng; } lint;
69 	struct { char c0, c1, c2, c3; } chars;
70 };
71 
72 /* character counters */
73 long	count [END+1];
74 union	FOUR insize;
75 long	outsize;
76 long	dictsize;
77 int	diffbytes;
78 
79 /* i/o stuff */
80 char	vflag = 0;
81 int	force = 0;	/* allow forced packing for consistency in directory */
82 
83 static	char filename [MAXPATHLEN];
84 static int max_name;
85 static int max_path = MAXPATHLEN;
86 
87 int	infile;		/* unpacked file */
88 int	outfile;	/* packed file */
89 char	inbuff [BUFSIZ];
90 char	outbuff [BUFSIZ+4];
91 
92 /* variables associated with the tree */
93 int	maxlev;
94 int	levcount [25];
95 int	lastnode;
96 int	parent [2*END+1];
97 
98 /* variables associated with the encoding process */
99 char	length [END+1];
100 long	bits [END+1];
101 union	FOUR mask;
102 long	inc;
103 #if defined(_LITTLE_ENDIAN)
104 char	*maskshuff[4]  = {&(mask.chars.c3),
105 			    &(mask.chars.c2),
106 			    &(mask.chars.c1),
107 			    &(mask.chars.c0)};
108 #elif defined(_BIG_ENDIAN)
109 char	*maskshuff[4]  = {&(mask.chars.c0),
110 			    &(mask.chars.c1),
111 			    &(mask.chars.c2),
112 			    &(mask.chars.c3)};
113 #else
114 #error Unknown byte ordering!
115 #endif
116 
117 /* the heap */
118 int	n;
119 struct	heap {
120 	long int count;
121 	int node;
122 } heap [END+2];
123 #define	hmove(a, b) {(b).count = (a).count; (b).node = (a).node; }
124 
125 static void heapify(int i);
126 static int mv_xattrs(int, int, char *, int);
127 
128 /* gather character frequency statistics */
129 /* return 1 if successful, 0 otherwise */
130 input(char *source)
131 {
132 	register int i;
133 	for (i = 0; i < END; i++)
134 		count[i] = 0;
135 	while ((i = read(infile, inbuff, BUFSIZ)) > 0)
136 		while (i > 0)
137 			count[inbuff[--i]&0377] += 2;
138 	if (i == 0)
139 		return (1);
140 	fprintf(stderr, gettext(
141 		"pack: %s: read error - file unchanged: "), source);
142 	perror("");
143 	return (0);
144 }
145 
146 /* encode the current file */
147 /* return 1 if successful, 0 otherwise */
148 output(char *source)
149 {
150 	int c, i, inleft;
151 	char *inp;
152 	register char **q, *outp;
153 	register int bitsleft;
154 	long temp;
155 
156 	/* output ``PACKED'' header */
157 	outbuff[0] = 037; 	/* ascii US */
158 	outbuff[1] = 036; 	/* ascii RS */
159 	/* output the length and the dictionary */
160 	temp = insize.lint.lng;
161 	for (i = 5; i >= 2; i--) {
162 		outbuff[i] =  (char)(temp & 0377);
163 		temp >>= 8;
164 	}
165 	outp = &outbuff[6];
166 	*outp++ = maxlev;
167 	for (i = 1; i < maxlev; i++)
168 		*outp++ = levcount[i];
169 	*outp++ = levcount[maxlev]-2;
170 	for (i = 1; i <= maxlev; i++)
171 		for (c = 0; c < END; c++)
172 			if (length[c] == i)
173 				*outp++ = c;
174 	dictsize = outp-&outbuff[0];
175 
176 	/* output the text */
177 	lseek(infile, 0L, 0);
178 	outsize = 0;
179 	bitsleft = 8;
180 	inleft = 0;
181 	do {
182 		if (inleft <= 0) {
183 			inleft = read(infile, inp = &inbuff[0], BUFSIZ);
184 			if (inleft < 0) {
185 				fprintf(stderr, gettext(
186 				    "pack: %s: read error - file unchanged: "),
187 					    source);
188 				perror("");
189 				return (0);
190 			}
191 		}
192 		c = (--inleft < 0) ? END : (*inp++ & 0377);
193 		mask.lint.lng = bits[c]<<bitsleft;
194 		q = &maskshuff[0];
195 		if (bitsleft == 8)
196 			*outp = **q++;
197 		else
198 			*outp |= **q++;
199 		bitsleft -= length[c];
200 		while (bitsleft < 0) {
201 			*++outp = **q++;
202 			bitsleft += 8;
203 		}
204 		if (outp >= &outbuff[BUFSIZ]) {
205 			if (write(outfile, outbuff, BUFSIZ) != BUFSIZ) {
206 wrerr:				fprintf(stderr, gettext(
207 				"pack: %s.z: write error - file unchanged: "),
208 					source);
209 				perror("");
210 				return (0);
211 			}
212 			((union FOUR *)outbuff)->lint.lng =
213 				    ((union FOUR *)&outbuff[BUFSIZ])->lint.lng;
214 			outp -= BUFSIZ;
215 			outsize += BUFSIZ;
216 		}
217 	} while (c != END);
218 	if (bitsleft < 8)
219 		outp++;
220 	c = outp-outbuff;
221 	if (write(outfile, outbuff, c) != c)
222 		goto wrerr;
223 	outsize += c;
224 	return (1);
225 }
226 
227 /* makes a heap out of heap[i],...,heap[n] */
228 void
229 heapify(int i)
230 {
231 	register int k;
232 	int lastparent;
233 	struct heap heapsubi;
234 	hmove(heap[i], heapsubi);
235 	lastparent = n/2;
236 	while (i <= lastparent) {
237 		k = 2*i;
238 		if (heap[k].count > heap[k+1].count && k < n)
239 			k++;
240 		if (heapsubi.count < heap[k].count)
241 			break;
242 		hmove(heap[k], heap[i]);
243 		i = k;
244 	}
245 	hmove(heapsubi, heap[i]);
246 }
247 
248 /* return 1 after successful packing, 0 otherwise */
249 int
250 packfile(char *source)
251 {
252 	register int c, i, p;
253 	long bitsout;
254 
255 	/* gather frequency statistics */
256 	if (input(source) == 0)
257 		return (0);
258 
259 	/* put occurring chars in heap with their counts */
260 	diffbytes = -1;
261 	count[END] = 1;
262 	insize.lint.lng = n = 0;
263 	for (i = END; i >= 0; i--) {
264 		parent[i] = 0;
265 		if (count[i] > 0) {
266 			diffbytes++;
267 			insize.lint.lng += count[i];
268 			heap[++n].count = count[i];
269 			heap[n].node = i;
270 		}
271 	}
272 	if (diffbytes == 1) {
273 		fprintf(stderr, gettext(
274 			"pack: %s: trivial file - file unchanged\n"), source);
275 		return (0);
276 	}
277 	insize.lint.lng >>= 1;
278 	for (i = n/2; i >= 1; i--)
279 		heapify(i);
280 
281 	/* build Huffman tree */
282 	lastnode = END;
283 	while (n > 1) {
284 		parent[heap[1].node] = ++lastnode;
285 		inc = heap[1].count;
286 		hmove(heap[n], heap[1]);
287 		n--;
288 		heapify(1);
289 		parent[heap[1].node] = lastnode;
290 		heap[1].node = lastnode;
291 		heap[1].count += inc;
292 		heapify(1);
293 	}
294 	parent[lastnode] = 0;
295 
296 	/* assign lengths to encoding for each character */
297 	bitsout = maxlev = 0;
298 	for (i = 1; i <= 24; i++)
299 		levcount[i] = 0;
300 	for (i = 0; i <= END; i++) {
301 		c = 0;
302 		for (p = parent[i]; p != 0; p = parent[p])
303 			c++;
304 		levcount[c]++;
305 		length[i] = c;
306 		if (c > maxlev)
307 			maxlev = c;
308 		bitsout += c*(count[i]>>1);
309 	}
310 	if (maxlev > 24) {
311 		/* can't occur unless insize.lint.lng >= 2**24 */
312 		fprintf(stderr, gettext(
313 	"pack: %s: Huffman tree has too many levels - file unchanged\n"),
314 			source);
315 		return (0);
316 	}
317 
318 	/* don't bother if no compression results */
319 	outsize = ((bitsout+7)>>3)+6+maxlev+diffbytes;
320 	if ((insize.lint.lng+BUFSIZ-1)/BUFSIZ <=
321 				    (outsize+BUFSIZ-1)/BUFSIZ && !force) {
322 		printf(gettext(
323 			"pack: %s: no saving - file unchanged\n"), source);
324 		return (0);
325 	}
326 
327 	/* compute bit patterns for each character */
328 	inc = 1L << 24;
329 	inc >>= maxlev;
330 	mask.lint.lng = 0;
331 	for (i = maxlev; i > 0; i--) {
332 		for (c = 0; c <= END; c++)
333 			if (length[c] == i) {
334 				bits[c] = mask.lint.lng;
335 				mask.lint.lng += inc;
336 			}
337 		mask.lint.lng &= ~inc;
338 		inc <<= 1;
339 	}
340 
341 	return (output(source));
342 }
343 
344 main(int argc, char *argv[])
345 {
346 	extern  int optind;
347 	register int i;
348 	register char *cp;
349 	int k, sep, errflg = 0;
350 	int c;
351 	int fcount = 0; /* count failures */
352 
353 	(void) setlocale(LC_ALL, "");
354 #if !defined(TEXT_DOMAIN)	/* Should be defined by cc -D */
355 #define	TEXT_DOMAIN "SYS_TEST"	/* Use this only if it weren't */
356 #endif
357 	(void) textdomain(TEXT_DOMAIN);
358 
359 	while ((c = getopt(argc, argv, "f-")) != EOF) {
360 		if (c == 'f')
361 			force++;
362 		else
363 			++errflg;
364 	}
365 	/*
366 	 * Check for invalid option.  Also check for missing
367 	 * file operand, ie: "pack" or "pack -".
368 	 */
369 	argc -= optind;
370 	argv = &argv[optind];
371 	if (errflg || argc < 1 ||
372 		(argc == 1 && argv[0][0] == '-' && argv[0][1] == '\0')) {
373 		fprintf(stderr, gettext(
374 			"usage: pack [-f] [-] file...\n"));
375 		if (argc < 1 ||
376 			(argc == 1 && argv[0][0] == '-' &&
377 				argv[0][1] == '\0')) {
378 			/*
379 			 * return 1 for usage error when no file was specified
380 			 */
381 			return (1);
382 		}
383 	}
384 	/* loop through the file names */
385 	for (k = 0; k < argc; k++) {
386 		if (argv[k][0] == '-' && argv[k][1] == '\0') {
387 			vflag = 1 - vflag;
388 			continue;
389 		}
390 		fcount++; /* increase failure count - expect the worst */
391 		if (errflg) {
392 			/*
393 			 * invalid option; just count the number of files not
394 			 * packed
395 			 */
396 			continue;
397 		}
398 		/* remove any .z suffix the user may have added */
399 		for (cp = argv[k]; *cp != '\0'; ++cp)
400 			;
401 		if (cp[-1] == SUF1 && cp[-2] == SUF0) {
402 			*cp-- = '\0'; *cp-- = '\0'; *cp = '\0';
403 		}
404 		sep = -1;  cp = filename;
405 		max_name = pathconf(argv[k], _PC_NAME_MAX);
406 		if (max_name == -1) {
407 			/* pathname invalid or no limit on length of filename */
408 			max_name = _POSIX_NAME_MAX;
409 		}
410 		/* copy argv[k] to filename and count chars in base name */
411 		for (i = 0; i < (MAXPATHLEN-3) && (*cp = argv[k][i]); i++)
412 			if (*cp++ == '/') sep = i;
413 		if ((infile = open(filename, 0)) < 0) {
414 			fprintf(stderr, gettext(
415 				"pack: %s: cannot open: "), filename);
416 			perror("");
417 			continue;
418 		}
419 		if (i >= (MAXPATHLEN-3) || (i-sep) > (max_name - 1)) {
420 			fprintf(stderr, gettext(
421 				"pack: %s: file name too long\n"), argv[k]);
422 			continue;
423 		}
424 		fstat(infile, &status);
425 		if (status.st_mode&S_IFDIR) {
426 			fprintf(stderr, gettext(
427 				"pack: %s: cannot pack a directory\n"),
428 				    argv[k]);
429 			goto closein;
430 		}
431 		if (status.st_size == 0) {
432 			fprintf(stderr, gettext(
433 				"pack: %s: cannot pack a zero length file\n"),
434 				argv[k]);
435 			goto closein;
436 		}
437 		if (status.st_nlink != 1) {
438 			fprintf(stderr, gettext(
439 				"pack: %s: has links\n"),
440 				argv[k]);
441 			goto closein;
442 		}
443 		*cp++ = SUF0;  *cp++ = SUF1;  *cp = '\0';
444 		if (stat(filename, &ostatus) != -1) {
445 			fprintf(stderr, gettext(
446 				"pack: %s: already exists\n"), filename);
447 			goto closein;
448 		}
449 		if ((outfile = creat(filename, status.st_mode)) < 0) {
450 			fprintf(stderr, gettext(
451 				"pack: %s: cannot create: "), filename);
452 			perror("");
453 			goto closein;
454 		}
455 
456 		if (packfile(argv[k]) &&
457 		    ((pathconf(argv[k], _PC_XATTR_EXISTS) != 1) ||
458 				(mv_xattrs(infile, outfile,
459 					argv[k], 0) == 0))) {
460 			if (unlink(argv[k]) != 0) {
461 				fprintf(stderr, gettext(
462 					"pack: %s: cannot unlink: "),
463 					argv[k]);
464 				perror("");
465 			}
466 			printf(gettext(
467 				"pack: %s: %.1f%% Compression\n"),
468 				argv[k],
469 	    ((double)(-outsize+(insize.lint.lng))/(double)insize.lint.lng)*100);
470 			/* output statistics */
471 			if (vflag) {
472 				printf(gettext("\tfrom %ld to %ld bytes\n"),
473 					insize.lint.lng, outsize);
474 				printf(gettext(
475 				"\tHuffman tree has %d levels below root\n"),
476 				    maxlev);
477 				printf(gettext(
478 					"\t%d distinct bytes in input\n"),
479 					diffbytes);
480 				printf(gettext(
481 					"\tdictionary overhead = %ld bytes\n"),
482 					dictsize);
483 				printf(gettext(
484 				    "\teffective  entropy  = %.2f bits/byte\n"),
485 			    ((double)outsize / (double)insize.lint.lng) * 8);
486 				printf(gettext(
487 				    "\tasymptotic entropy  = %.2f bits/byte\n"),
488 					((double)(outsize-dictsize) /
489 					(double)insize.lint.lng) * 8);
490 			}
491 			u_times.actime = status.st_atime;
492 			u_times.modtime = status.st_mtime;
493 			if (utime(filename, &u_times) != 0) {
494 				errflg++;
495 				fprintf(stderr,
496 					gettext(
497 					"pack: cannot change times on %s: "),
498 					filename);
499 				perror("");
500 			}
501 			if (chmod(filename, status.st_mode) != 0) {
502 				errflg++;
503 				fprintf(stderr,
504 					gettext(
505 				"pack: can't change mode to %o on %s: "),
506 					status.st_mode, filename);
507 				perror("");
508 			}
509 			chown(filename, status.st_uid, status.st_gid);
510 			if (!errflg)
511 				fcount--;  /* success after all */
512 		} else {
513 			if (pathconf(filename, _PC_XATTR_EXISTS) == 1) {
514 				(void) mv_xattrs(outfile, infile, filename, 1);
515 			}
516 			unlink(filename);
517 		}
518 closein:	close(outfile);
519 		close(infile);
520 	}
521 	return (fcount);
522 }
523 
524 /*
525  * mv_xattrs - move (via renameat) all of the extended attributes
526  *	associated with the file referenced by infd to the file
527  *	referenced by outfd.  The infile and silent arguments are
528  *	provided for error message processing.  This function
529  *	returns 0 on success and -1 on error.
530  */
531 static int
532 mv_xattrs(int infd, int outfd, char *infile, int silent)
533 {
534 	int indfd, outdfd, tmpfd;
535 	DIR *dirp = NULL;
536 	struct dirent *dp = NULL;
537 	int error = 0;
538 	char *etext;
539 
540 	indfd = outdfd = tmpfd = -1;
541 
542 	if ((indfd = openat(infd, ".", O_RDONLY|O_XATTR)) == -1) {
543 		etext = gettext("cannot open source");
544 		error = -1;
545 		goto out;
546 	}
547 
548 	if ((outdfd = openat(outfd, ".", O_RDONLY|O_XATTR)) == -1) {
549 		etext = gettext("cannot open target");
550 		error = -1;
551 		goto out;
552 	}
553 
554 	if ((tmpfd = dup(indfd)) == -1) {
555 		etext = gettext("cannot dup descriptor");
556 		error = -1;
557 		goto out;
558 
559 	}
560 	if ((dirp = fdopendir(tmpfd)) == NULL) {
561 		etext = gettext("cannot access source");
562 		error = -1;
563 		goto out;
564 	}
565 
566 	while (dp = readdir(dirp)) {
567 		if ((dp->d_name[0] == '.' && dp->d_name[1] == '\0') ||
568 		    (dp->d_name[0] == '.' && dp->d_name[1] == '.' &&
569 		    dp->d_name[2] == '\0'))
570 			continue;
571 		if ((renameat(indfd, dp->d_name, outdfd, dp->d_name)) == -1) {
572 			etext = dp->d_name;
573 			error = -1;
574 			goto out;
575 		}
576 	}
577 out:
578 	if (error == -1 && silent == 0) {
579 		fprintf(stderr, gettext(
580 			"pack: %s: cannot move extended attributes, "),
581 			infile);
582 		perror(etext);
583 	}
584 	if (dirp)
585 		closedir(dirp);
586 	if (indfd != -1)
587 		close(indfd);
588 	if (outdfd != -1)
589 		close(outdfd);
590 	return (error);
591 }
592