xref: /illumos-gate/usr/src/cmd/compress/compress.c (revision fe4627ef755b7c263f91a0e6f07cdca5d7083501)
1 /*
2  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
7 /*	  All Rights Reserved  	*/
8 
9 
10 /*
11  * Copyright (c) 1986 Regents of the University of California.
12  * All rights reserved.  The Berkeley software License Agreement
13  * specifies the terms and conditions for redistribution.
14  */
15 
16 #pragma ident	"%Z%%M%	%I%	%E% SMI"
17 
18 /*
19  * Compress - data compression program
20  */
21 #define	min(a, b)	((a > b) ? b : a)
22 
23 /*
24  * machine variants which require cc -Dmachine:  pdp11, z8000, pcxt
25  */
26 
27 /*
28  * Set USERMEM to the maximum amount of physical user memory available
29  * in bytes.  USERMEM is used to determine the maximum BITS that can be used
30  * for compression.
31  *
32  * SACREDMEM is the amount of physical memory saved for others; compress
33  * will hog the rest.
34  */
35 #ifndef SACREDMEM
36 #define	SACREDMEM	0
37 #endif
38 
39 #ifndef USERMEM
40 #define	USERMEM 	450000	/* default user memory */
41 #endif
42 
43 #ifdef USERMEM
44 #if USERMEM >= (433484+SACREDMEM)
45 #define	PBITS	16
46 #else
47 #if USERMEM >= (229600+SACREDMEM)
48 #define	PBITS	15
49 #else
50 #if USERMEM >= (127536+SACREDMEM)
51 #define	PBITS	14
52 #else
53 #if USERMEM >= (73464+SACREDMEM)
54 #define	PBITS	13
55 #else
56 #define	PBITS	12
57 #endif
58 #endif
59 #endif
60 #endif
61 #undef USERMEM
62 #endif /* USERMEM */
63 
64 #ifdef PBITS		/* Preferred BITS for this memory size */
65 #ifndef BITS
66 #define	BITS PBITS
67 #endif /* BITS */
68 #endif /* PBITS */
69 
70 #if BITS == 16
71 #define	HSIZE	69001		/* 95% occupancy */
72 #endif
73 #if BITS == 15
74 #define	HSIZE	35023		/* 94% occupancy */
75 #endif
76 #if BITS == 14
77 #define	HSIZE	18013		/* 91% occupancy */
78 #endif
79 #if BITS == 13
80 #define	HSIZE	9001		/* 91% occupancy */
81 #endif
82 #if BITS <= 12
83 #define	HSIZE	5003		/* 80% occupancy */
84 #endif
85 
86 #define	OUTSTACKSIZE	(2<<BITS)
87 
88 /*
89  * a code_int must be able to hold 2**BITS values of type int, and also -1
90  */
91 #if BITS > 15
92 typedef long int	code_int;
93 #else
94 typedef int		code_int;
95 #endif
96 
97 typedef long int	count_int;
98 typedef long long	count_long;
99 
100 typedef	unsigned char	char_type;
101 
102 static char_type magic_header[] = { "\037\235" }; /* 1F 9D */
103 
104 /* Defines for third byte of header */
105 #define	BIT_MASK	0x1f
106 #define	BLOCK_MASK	0x80
107 /*
108  * Masks 0x40 and 0x20 are free.  I think 0x20 should mean that there is
109  * a fourth header byte(for expansion).
110  */
111 #define	INIT_BITS 9			/* initial number of bits/code */
112 
113 /*
114  * compress.c - File compression ala IEEE Computer, June 1984.
115  */
116 static char rcs_ident[] =
117 	"$Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $";
118 
119 #include <ctype.h>
120 #include <signal.h>
121 #include <sys/param.h>
122 #include <locale.h>
123 #include <langinfo.h>
124 #include <sys/acl.h>
125 #include <utime.h>
126 #include <libgen.h>
127 #include <setjmp.h>
128 #include <aclutils.h>
129 #include <libcmdutils.h>
130 #include "getresponse.h"
131 
132 
133 static int n_bits;			/* number of bits/code */
134 static int maxbits = BITS;	/* user settable max # bits/code */
135 static code_int maxcode;	/* maximum code, given n_bits */
136 			/* should NEVER generate this code */
137 static code_int maxmaxcode = 1 << BITS;
138 #define	MAXCODE(n_bits)	((1 << (n_bits)) - 1)
139 
140 static count_int htab [OUTSTACKSIZE];
141 static unsigned short codetab [OUTSTACKSIZE];
142 
143 #define	htabof(i)	htab[i]
144 #define	codetabof(i)	codetab[i]
145 static code_int hsize = HSIZE; /* for dynamic table sizing */
146 static off_t	fsize;	/* file size of input file */
147 
148 /*
149  * To save much memory, we overlay the table used by compress() with those
150  * used by decompress().  The tab_prefix table is the same size and type
151  * as the codetab.  The tab_suffix table needs 2**BITS characters.  We
152  * get this from the beginning of htab.  The output stack uses the rest
153  * of htab, and contains characters.  There is plenty of room for any
154  * possible stack (stack used to be 8000 characters).
155  */
156 
157 #define	tab_prefixof(i)		codetabof(i)
158 #define	tab_suffixof(i)		((char_type *)(htab))[i]
159 #define	de_stack		((char_type *)&tab_suffixof(1<<BITS))
160 #define	stack_max		((char_type *)&tab_suffixof(OUTSTACKSIZE))
161 
162 static code_int free_ent = 0; /* first unused entry */
163 static int newline_needed = 0;
164 static int didnt_shrink = 0;
165 static int perm_stat = 0;	/* permanent status */
166 
167 static code_int getcode();
168 
169 	/* Use a 3-byte magic number header, unless old file */
170 static int nomagic = 0;
171 	/* Write output on stdout, suppress messages */
172 static int zcat_flg = 0;	/* use stdout on all files */
173 static int zcat_cmd = 0;	/* zcat cmd */
174 static int use_stdout = 0;	/* set for each file processed */
175 	/* Don't unlink output file on interrupt */
176 static int precious = 1;
177 static int quiet = 1;	/* don't tell me about compression */
178 
179 /*
180  * block compression parameters -- after all codes are used up,
181  * and compression rate changes, start over.
182  */
183 static int block_compress = BLOCK_MASK;
184 static int clear_flg = 0;
185 static long int ratio = 0;
186 #define	CHECK_GAP 10000	/* ratio check interval */
187 static count_long checkpoint = CHECK_GAP;
188 /*
189  * the next two codes should not be changed lightly, as they must not
190  * lie within the contiguous general code space.
191  */
192 #define	FIRST	257	/* first free entry */
193 #define	CLEAR	256	/* table clear output code */
194 
195 static int force = 0;
196 static char ofname [MAXPATHLEN];
197 
198 static int Vflg = 0;
199 static int vflg = 0;
200 static int qflg = 0;
201 static int bflg = 0;
202 static int Fflg = 0;
203 static int dflg = 0;
204 static int cflg = 0;
205 static int Cflg = 0;
206 
207 #ifdef DEBUG
208 int verbose = 0;
209 int debug = 0;
210 #endif /* DEBUG */
211 
212 static void (*oldint)();
213 static int bgnd_flag;
214 
215 static int do_decomp = 0;
216 
217 static char *progname;
218 static char *optstr;
219 /*
220  * Fix lint errors
221  */
222 
223 static char *local_basename(char *);
224 
225 static int  addDotZ(char *, size_t);
226 
227 static void Usage(void);
228 static void cl_block(count_long);
229 static void cl_hash(count_int);
230 static void compress(void);
231 static void copystat(char *, struct stat *, char *);
232 static void decompress(void);
233 static void ioerror(void);
234 static void onintr();
235 static void oops();
236 static void output(code_int);
237 static void prratio(FILE *, count_long, count_long);
238 static void version(void);
239 
240 #ifdef DEBUG
241 static int in_stack(int, int);
242 static void dump_tab(void);
243 static void printcodes(void);
244 #endif
245 
246 /* For error-handling */
247 
248 static jmp_buf env;
249 
250 /* For input and ouput */
251 
252 static FILE *inp;		/* the current input file */
253 static FILE *infile;		/* disk-based input stream */
254 static FILE *outp;		/* current output file */
255 static FILE *outfile;		/* disk-based output stream */
256 
257 /* For output() */
258 
259 static char buf[BITS];
260 
261 static char_type lmask[9] =
262 	{0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00};
263 static char_type rmask[9] =
264 	{0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
265 
266 /* For compress () */
267 
268 static int offset;
269 static count_long bytes_out;	/* length of compressed output */
270 	/* # of codes output (for debugging) */
271 
272 /* For dump_tab() */
273 
274 #define	STACK_SIZE	15000
275 #ifdef DEBUG
276 code_int sorttab[1<<BITS];	/* sorted pointers into htab */
277 #endif
278 
279 /* Extended system attribute support */
280 
281 static int saflg = 0;
282 
283 /*
284  * *************************************************************
285  * TAG( main )
286  *
287  * Algorithm from "A Technique for High Performance Data Compression",
288  * Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19.
289  *
290  * Usage: compress [-dfvc/] [-b bits] [file ...]
291  * Inputs:
292  *	-d:	    If given, decompression is done instead.
293  *
294  *	-c:	    Write output on stdout, don't remove original.
295  *
296  *	-b:	    Parameter limits the max number of bits/code.
297  *
298  *	-f:	    Forces output file to be generated, even if one already
299  *		    exists, and even if no space is saved by compressing.
300  *		    If -f is not used, the user will be prompted if stdin is
301  *		    a tty, otherwise, the output file will not be overwritten.
302  *
303  *	-/	    Copies extended attributes and extended system attributes.
304  *
305  *  -v:	    Write compression statistics
306  *
307  * 	file ...:   Files to be compressed.  If none specified, stdin
308  *		    is used.
309  * Outputs:
310  *	file.Z:	    Compressed form of file with same mode, owner, and utimes
311  * 	or stdout   (if stdin used as input)
312  *
313  * Assumptions:
314  * When filenames are given, replaces with the compressed version
315  * (.Z suffix) only if the file decreases in size.
316  * Algorithm:
317  * Modified Lempel-Ziv method (LZW).  Basically finds common
318  * substrings and replaces them with a variable size code.  This is
319  * deterministic, and can be done on the fly.  Thus, the decompression
320  * procedure needs no input table, but tracks the way the table was built.
321  */
322 
323 int
324 main(int argc, char *argv[])
325 {
326 	int overwrite = 0;	/* Do not overwrite unless given -f flag */
327 	char tempname[MAXPATHLEN];
328 	char line[LINE_MAX];
329 	char **filelist, **fileptr;
330 	char *cp;
331 	struct stat statbuf;
332 	struct stat ostatbuf;
333 	int ch;				/* XCU4 */
334 	char	*p;
335 	extern int optind, optopt;
336 	extern char *optarg;
337 	int dash_count = 0;		/* times "-" is on cmdline */
338 
339 	/* XCU4 changes */
340 	(void) setlocale(LC_ALL, "");
341 #if !defined(TEXT_DOMAIN)	/* Should be defined by cc -D */
342 #define	TEXT_DOMAIN "SYS_TEST"	/* Use this only if it weren't */
343 #endif
344 	(void) textdomain(TEXT_DOMAIN);
345 
346 	if (init_yes() < 0) {
347 		(void) fprintf(stderr, gettext(ERR_MSG_INIT_YES),
348 		    strerror(errno));
349 		exit(1);
350 	}
351 
352 	/* This bg check only works for sh. */
353 	if ((oldint = signal(SIGINT, SIG_IGN)) != SIG_IGN) {
354 		(void) signal(SIGINT, onintr);
355 		(void) signal(SIGSEGV, oops);
356 	}
357 	bgnd_flag = oldint != SIG_DFL;
358 
359 	/* Allocate room for argv + "-" (if stdin needs to be added) */
360 
361 	filelist = fileptr = (char **)(malloc((argc + 1) * sizeof (*argv)));
362 	*filelist = NULL;
363 
364 	if ((cp = rindex(argv[0], '/')) != 0) {
365 		cp++;
366 	} else {
367 		cp = argv[0];
368 	}
369 
370 	if (strcmp(cp, "uncompress") == 0) {
371 		do_decomp = 1;
372 	} else if (strcmp(cp, "zcat") == 0) {
373 		do_decomp = 1;
374 		zcat_cmd = zcat_flg = 1;
375 	}
376 
377 	progname = local_basename(argv[0]);
378 
379 	/*
380 	 * Argument Processing
381 	 * All flags are optional.
382 	 * -D = > debug
383 	 * -V = > print Version; debug verbose
384 	 * -d = > do_decomp
385 	 * -v = > unquiet
386 	 * -f = > force overwrite of output file
387 	 * -n = > no header: useful to uncompress old files
388 	 * -b	  maxbits => maxbits.  If -b is specified,
389 	 *	  then maxbits MUST be given also.
390 	 * -c = > cat all output to stdout
391 	 * -C = > generate output compatible with compress 2.0.
392 	 * if a string is left, must be an input filename.
393 	 */
394 #ifdef DEBUG
395 	optstr = "b:cCdDfFnqvV/";
396 #else
397 	optstr = "b:cCdfFnqvV/";
398 #endif
399 
400 	while ((ch = getopt(argc, argv, optstr)) != EOF) {
401 		/* Process all flags in this arg */
402 		switch (ch) {
403 #ifdef DEBUG
404 			case 'D':
405 				debug = 1;
406 				break;
407 			case 'V':
408 				verbose = 1;
409 				version();
410 				break;
411 #else
412 			case 'V':
413 				version();
414 				Vflg++;
415 				break;
416 #endif /* DEBUG */
417 			case 'v':
418 				quiet = 0;
419 				vflg++;
420 				break;
421 			case 'd':
422 				do_decomp = 1;
423 				dflg++;
424 				break;
425 			case 'f':
426 			case 'F':
427 				Fflg++;
428 				overwrite = 1;
429 				force = 1;
430 				break;
431 			case 'n':
432 				nomagic = 1;
433 				break;
434 			case 'C':
435 				Cflg++;
436 				block_compress = 0;
437 				break;
438 			case 'b':
439 				bflg++;
440 				p = optarg;
441 				if (!p) {
442 					(void) fprintf(stderr, gettext(
443 					    "Missing maxbits\n"));
444 					Usage();
445 					exit(1);
446 				}
447 				maxbits = strtoul(optarg, &p, 10);
448 				if (*p) {
449 					(void) fprintf(stderr, gettext(
450 					    "Missing maxbits\n"));
451 					Usage();
452 					exit(1);
453 				}
454 				break;
455 
456 			case 'c':
457 				cflg++;
458 				zcat_flg = 1;
459 				break;
460 			case 'q':
461 				qflg++;
462 				quiet = 1;
463 				break;
464 			case '/':
465 				saflg++;
466 				break;
467 			default:
468 				(void) fprintf(stderr, gettext(
469 				    "Unknown flag: '%c'\n"), optopt);
470 				Usage();
471 				exit(1);
472 		}
473 	} /* while */
474 
475 	/*
476 	 * Validate zcat syntax
477 	 */
478 
479 	if (zcat_cmd && (Fflg | Cflg | cflg |
480 	    bflg | qflg | dflg | nomagic)) {
481 		(void) fprintf(stderr, gettext(
482 		    "Invalid Option\n"));
483 		Usage();
484 		exit(1);
485 	}
486 
487 	/*
488 	 * Process the file list
489 	 */
490 
491 	for (; optind < argc; optind++) {
492 		if (strcmp(argv[optind], "-") == 0) {
493 			dash_count++;
494 		}
495 
496 		*fileptr++ = argv[optind];	/* Build input file list */
497 		*fileptr = NULL;
498 	}
499 
500 	if (dash_count > 1) {
501 		(void) fprintf(stderr,
502 		    gettext("%s may only appear once in the file"
503 		    " list\n"), "\"-\"");
504 		exit(1);
505 	}
506 
507 	if (fileptr - filelist == 0) {
508 		*fileptr++ = "-";
509 		*fileptr = NULL;
510 	}
511 
512 	if (fileptr - filelist > 1 && cflg && !do_decomp) {
513 		(void) fprintf(stderr,
514 		    gettext("compress: only one file may be compressed"
515 		    " to stdout\n"));
516 		exit(1);
517 	}
518 
519 	if (maxbits < INIT_BITS)
520 		maxbits = INIT_BITS;
521 	if (maxbits > BITS)
522 		maxbits = BITS;
523 	maxmaxcode = 1 << maxbits;
524 
525 	/* Need to open something to close with freopen later */
526 
527 	if ((infile = fopen("/dev/null", "r")) == NULL) {
528 		(void) fprintf(stderr, gettext("Error opening /dev/null for "
529 		    "input\n"));
530 		exit(1);
531 	}
532 
533 	if ((outfile = fopen("/dev/null", "w")) == NULL) {
534 		(void) fprintf(stderr, gettext("Error opening /dev/null for "
535 		    "output\n"));
536 		exit(1);
537 	}
538 
539 	for (fileptr = filelist; *fileptr; fileptr++) {
540 		int jmpval = 0;
541 		didnt_shrink = 0;
542 		newline_needed = 0;
543 
544 		if (do_decomp) {
545 			/* DECOMPRESSION */
546 
547 			if (strcmp(*fileptr, "-") == 0) {
548 				/* process stdin */
549 				inp = stdin;
550 				outp = stdout;
551 				use_stdout = 1;
552 				*fileptr = "stdin"; /* for error messages */
553 			} else {
554 				/* process the named file */
555 
556 				inp = infile;
557 				outp = outfile;
558 				use_stdout = 0;
559 
560 				if (zcat_flg) {
561 					use_stdout = 1;
562 					outp = stdout;
563 				}
564 
565 				/* Check for .Z suffix */
566 
567 				if (strcmp(*fileptr +
568 				    strlen(*fileptr) - 2, ".Z") != 0) {
569 					/* No .Z: tack one on */
570 
571 					if (strlcpy(tempname, *fileptr,
572 					    sizeof (tempname)) >=
573 					    sizeof (tempname)) {
574 						(void) fprintf(stderr,
575 						    gettext("%s: filename "
576 						    "too long\n"),
577 						    *fileptr);
578 						perm_stat = 1;
579 						continue;
580 					}
581 
582 					if (addDotZ(tempname,
583 					    sizeof (tempname)) < 0) {
584 						perm_stat = 1;
585 						continue;
586 					}
587 
588 					*fileptr = tempname;
589 				}
590 
591 				/* Open input file */
592 
593 				if (stat(*fileptr, &statbuf) < 0) {
594 					perror(*fileptr);
595 					perm_stat = 1;
596 					continue;
597 				}
598 
599 				if ((freopen(*fileptr, "r", inp)) == NULL) {
600 					perror(*fileptr);
601 					perm_stat = 1;
602 					continue;
603 				}
604 			}
605 
606 			/* Check the magic number */
607 
608 			if (nomagic == 0) {
609 				if ((getc(inp) !=
610 				    (magic_header[0] & 0xFF)) ||
611 				    (getc(inp) !=
612 				    (magic_header[1] & 0xFF))) {
613 					(void) fprintf(stderr, gettext(
614 					    "%s: not in compressed "
615 					    "format\n"),
616 					    *fileptr);
617 					perm_stat = 1;
618 					continue;
619 				}
620 
621 				/* set -b from file */
622 				if ((maxbits = getc(inp)) == EOF &&
623 				    ferror(inp)) {
624 					perror(*fileptr);
625 					perm_stat = 1;
626 					continue;
627 				}
628 
629 				block_compress = maxbits & BLOCK_MASK;
630 				maxbits &= BIT_MASK;
631 				maxmaxcode = 1 << maxbits;
632 
633 				if (maxbits > BITS) {
634 					(void) fprintf(stderr,
635 					    gettext("%s: compressed "
636 					    "with %d bits, "
637 					    "can only handle"
638 					    " %d bits\n"),
639 					    *fileptr, maxbits, BITS);
640 					perm_stat = 1;
641 					continue;
642 				}
643 			}
644 
645 			if (!use_stdout) {
646 				/* Generate output filename */
647 
648 				if (strlcpy(ofname, *fileptr,
649 				    sizeof (ofname)) >=
650 				    sizeof (ofname)) {
651 					(void) fprintf(stderr,
652 					    gettext("%s: filename "
653 					    "too long\n"),
654 					    *fileptr);
655 					perm_stat = 1;
656 					continue;
657 				}
658 
659 				/* Strip off .Z */
660 
661 				ofname[strlen(*fileptr) - 2] = '\0';
662 			}
663 		} else {
664 			/* COMPRESSION */
665 
666 			if (strcmp(*fileptr, "-") == 0) {
667 				/* process stdin */
668 				inp = stdin;
669 				outp = stdout;
670 				use_stdout = 1;
671 				*fileptr = "stdin"; /* for error messages */
672 
673 				/* Use the largest possible hash table */
674 				hsize =  HSIZE;
675 			} else {
676 				/* process the named file */
677 
678 				inp = infile;
679 				outp = outfile;
680 				use_stdout = 0;
681 
682 				if (zcat_flg) {
683 					use_stdout = 1;
684 					outp = stdout;
685 				}
686 
687 				if (strcmp(*fileptr +
688 				    strlen(*fileptr) - 2, ".Z") == 0) {
689 					(void) fprintf(stderr, gettext(
690 					    "%s: already has .Z "
691 					    "suffix -- no change\n"),
692 					    *fileptr);
693 					perm_stat = 1;
694 					continue;
695 				}
696 				/* Open input file */
697 
698 				if (stat(*fileptr, &statbuf) < 0) {
699 					perror(*fileptr);
700 					perm_stat = 1;
701 					continue;
702 				}
703 
704 				if ((freopen(*fileptr, "r", inp)) == NULL) {
705 					perror(*fileptr);
706 					perm_stat = 1;
707 					continue;
708 				}
709 
710 				fsize = (off_t)statbuf.st_size;
711 
712 				/*
713 				 * tune hash table size for small
714 				 * files -- ad hoc,
715 				 * but the sizes match earlier #defines, which
716 				 * serve as upper bounds on the number of
717 				 * output codes.
718 				 */
719 				hsize = HSIZE;
720 				if (fsize < (1 << 12))
721 					hsize = min(5003, HSIZE);
722 				else if (fsize < (1 << 13))
723 					hsize = min(9001, HSIZE);
724 				else if (fsize < (1 << 14))
725 					hsize = min(18013, HSIZE);
726 				else if (fsize < (1 << 15))
727 					hsize = min(35023, HSIZE);
728 				else if (fsize < 47000)
729 					hsize = min(50021, HSIZE);
730 
731 				if (!use_stdout) {
732 					/* Generate output filename */
733 
734 					if (strlcpy(ofname, *fileptr,
735 					    sizeof (ofname)) >=
736 					    sizeof (ofname)) {
737 						(void) fprintf(stderr,
738 						    gettext("%s: filename "
739 						    "too long\n"),
740 						    *fileptr);
741 						perm_stat = 1;
742 						continue;
743 					}
744 
745 					if (addDotZ(ofname,
746 					    sizeof (ofname)) < 0) {
747 						perm_stat = 1;
748 						continue;
749 					}
750 				}
751 			}
752 		}	/* if (do_decomp) */
753 
754 		/* Check for overwrite of existing file */
755 
756 		if (!overwrite && !use_stdout) {
757 			if (stat(ofname, &ostatbuf) == 0) {
758 				(void) fprintf(stderr, gettext(
759 				    "%s already exists;"), ofname);
760 				if (bgnd_flag == 0 && isatty(2)) {
761 					int cin;
762 
763 					(void) fprintf(stderr, gettext(
764 					    " do you wish to overwr"
765 					    "ite %s (%s or %s)? "),
766 					    ofname, yesstr, nostr);
767 					(void) fflush(stderr);
768 					for (cin = 0; cin < LINE_MAX; cin++)
769 						line[cin] = 0;
770 					(void) read(2, line, LINE_MAX);
771 
772 					if (yes_check(line) == 0) {
773 						(void) fprintf(stderr,
774 						    gettext(
775 						    "\tnot overwri"
776 						    "tten\n"));
777 						continue;
778 					}
779 				} else {
780 					/*
781 					 * XPG4: Assertion 1009
782 					 * Standard input is not
783 					 * terminal, and no '-f',
784 					 * and file exists.
785 					 */
786 
787 					(void) fprintf(stderr, gettext(
788 					    "%s: File exists, -f not"
789 					    " specified, and ru"
790 					    "nning in the backgro"
791 					    "und.\n"), *fileptr);
792 					perm_stat = 1;
793 					continue;
794 				}
795 			}
796 		}
797 		if (!use_stdout) {
798 			if ((pathconf(ofname, _PC_XATTR_EXISTS) == 1) ||
799 			    (saflg && sysattr_support(ofname,
800 			    _PC_SATTR_EXISTS) == 1)) {
801 				(void) unlink(ofname);
802 			}
803 			/* Open output file */
804 			if (freopen(ofname, "w", outp) == NULL) {
805 				perror(ofname);
806 				perm_stat = 1;
807 				continue;
808 			}
809 			precious = 0;
810 			if (!quiet) {
811 				(void) fprintf(stderr, "%s: ",
812 				    *fileptr);
813 				newline_needed = 1;
814 			}
815 		} else if (!quiet && !do_decomp) {
816 			(void) fprintf(stderr, "%s: ",
817 			    *fileptr);
818 				newline_needed = 1;
819 		}
820 
821 		/* Actually do the compression/decompression */
822 
823 		if ((jmpval = setjmp(env)) == 0) {
824 			/* We'll see how things go */
825 #ifndef DEBUG
826 			if (do_decomp == 0)  {
827 				compress();
828 			} else {
829 				decompress();
830 			}
831 #else
832 			if (do_decomp == 0)  {
833 				compress();
834 			} else if (debug == 0)  {
835 				decompress();
836 			} else {
837 				printcodes();
838 			}
839 
840 			if (verbose) {
841 				dump_tab();
842 			}
843 #endif
844 		} else {
845 			/*
846 			 * Things went badly - clean up and go on.
847 			 * jmpval's values break down as follows:
848 			 *   1 == message determined by ferror() values.
849 			 *   2 == input problem message needed.
850 			 *   3 == output problem message needed.
851 			 */
852 
853 			if (ferror(inp) || jmpval == 2) {
854 				if (do_decomp) {
855 					(void) fprintf(stderr, gettext(
856 					    "uncompress: %s: corrupt"
857 					    " input\n"), *fileptr);
858 				} else {
859 					perror(*fileptr);
860 				}
861 			}
862 
863 			if (ferror(outp) || jmpval == 3) {
864 				/* handle output errors */
865 
866 				if (use_stdout) {
867 					perror("");
868 				} else {
869 					perror(ofname);
870 				}
871 			}
872 
873 			if (ofname[0] != '\0') {
874 				if (unlink(ofname) < 0)  {
875 					perror(ofname);
876 				}
877 
878 				ofname[0] = '\0';
879 			}
880 
881 			perm_stat = 1;
882 			continue;
883 		}
884 
885 		/* Things went well */
886 
887 		if (!use_stdout) {
888 				/* Copy stats */
889 			copystat(*fileptr, &statbuf, ofname);
890 			precious = 1;
891 			if (newline_needed) {
892 				(void) putc('\n', stderr);
893 			}
894 			/*
895 			 * Print the info. for unchanged file
896 			 * when no -v
897 			 */
898 
899 			if (didnt_shrink) {
900 				if (!force && perm_stat == 0) {
901 					if (quiet) {
902 						(void) fprintf(stderr, gettext(
903 						    "%s: -- file "
904 						    "unchanged\n"),
905 						    *fileptr);
906 					}
907 
908 					perm_stat = 2;
909 				}
910 			}
911 		} else {
912 			if (didnt_shrink && !force && perm_stat == 0) {
913 				perm_stat = 2;
914 			}
915 
916 			if (newline_needed) {
917 				(void) fprintf(stderr, "\n");
918 			}
919 		}
920 	}	/* for */
921 
922 	return (perm_stat);
923 }
924 
925 static void
926 cinterr(int hshift)
927 {
928 	/* we have exceeded the hash table */
929 	(void) fprintf(stderr,
930 	    "internal error: hashtable exceeded - hsize = %ld\n", hsize);
931 	(void) fprintf(stderr, "hshift = %d, %d\n", hshift, (1 << hshift) -1);
932 	(void) fprintf(stderr, "maxbits = %d\n", maxbits);
933 	(void) fprintf(stderr, "n_bits = %d\n", n_bits);
934 	(void) fprintf(stderr, "maxcode = %ld\n", maxcode);
935 	longjmp(env, 1);
936 }
937 
938 static code_int
939 adjusti(code_int i, code_int hsize_reg)
940 {
941 	while (i < 0) {
942 		i += hsize_reg;
943 	}
944 
945 	while (i >= hsize_reg) {
946 		i -= hsize_reg;
947 	}
948 	return (i);
949 }
950 
951 /*
952  * compress inp to outp
953  *
954  * Algorithm:  use open addressing double hashing(no chaining) on the
955  * prefix code / next character combination.  We do a variant of Knuth's
956  * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
957  * secondary probe.  Here, the modular division first probe is gives way
958  * to a faster exclusive-or manipulation.  Also do block compression with
959  * an adaptive reset, whereby the code table is cleared when the compression
960  * ratio decreases, but after the table fills.  The variable-length output
961  * codes are re-sized at this point, and a special CLEAR code is generated
962  * for the decompressor.  Late addition:  construct the table according to
963  * file size for noticeable speed improvement on small files.  Please direct
964  * questions about this implementation to ames!jaw.
965  */
966 
967 static void
968 compress()
969 {
970 	long fcode;
971 	code_int i = 0;
972 	int c;
973 	code_int ent;
974 	int disp;
975 	code_int hsize_reg;
976 	int hshift;
977 	int probecnt;
978 	count_long in_count;
979 	uint32_t inchi, inclo;
980 	int maxbits_reg;
981 	FILE *fin = inp;
982 #ifdef DEBUG
983 	count_long out_count = 0;
984 #endif
985 
986 	if (nomagic == 0) {
987 		if ((putc(magic_header[0], outp) == EOF ||
988 		    putc(magic_header[1], outp) == EOF ||
989 		    putc((char)(maxbits | block_compress),
990 		    outp) == EOF) &&
991 		    ferror(outp)) {
992 			ioerror();
993 		}
994 	}
995 
996 	offset = 0;
997 	bytes_out = 3;		/* includes 3-byte header mojo */
998 	clear_flg = 0;
999 	ratio = 0;
1000 	in_count = 1;
1001 	inchi = 0;
1002 	inclo = 1;
1003 	checkpoint = CHECK_GAP;
1004 	maxcode = MAXCODE(n_bits = INIT_BITS);
1005 	free_ent = ((block_compress) ? FIRST : 256);
1006 
1007 	if ((ent = getc(fin)) == EOF && ferror(fin)) {
1008 		ioerror();
1009 	}
1010 
1011 	hshift = 0;
1012 
1013 	for (fcode = (long)hsize;  fcode < 65536L; fcode *= 2L)
1014 		hshift++;
1015 
1016 	hshift = 8 - hshift;		/* set hash code range bound */
1017 
1018 	hsize_reg = hsize;
1019 	maxbits_reg = maxbits;
1020 
1021 	cl_hash((count_int) hsize_reg);		/* clear hash table */
1022 
1023 	while ((c = getc(fin)) != EOF) {
1024 		if (++inclo == 0)
1025 			inchi++;
1026 		fcode = (long)(((long)c << maxbits_reg) + ent);
1027 		i = ((c << hshift) ^ ent);	/* xor hashing */
1028 
1029 		if ((unsigned int)i >= hsize_reg)
1030 			i = adjusti(i, hsize_reg);
1031 
1032 		if (htabof(i) == fcode) {
1033 			ent = codetabof(i);
1034 			continue;
1035 		} else if ((long)htabof(i) < 0) {
1036 			/* empty slot */
1037 			goto nomatch;
1038 		}
1039 
1040 		/* secondary hash (after G. Knott) */
1041 		disp = hsize_reg - i;
1042 
1043 		if (i == 0) {
1044 			disp = 1;
1045 		}
1046 
1047 		probecnt = 0;
1048 	probe:
1049 		if (++probecnt > hsize_reg)
1050 			cinterr(hshift);
1051 
1052 		if ((i -= disp) < 0) {
1053 			while (i < 0)
1054 				i += hsize_reg;
1055 		}
1056 
1057 		if (htabof(i) == fcode) {
1058 			ent = codetabof(i);
1059 			continue;
1060 		}
1061 
1062 		if ((long)htabof(i) > 0) {
1063 			goto probe;
1064 		}
1065 	nomatch:
1066 		output((code_int) ent);
1067 #ifdef DEBUG
1068 		out_count++;
1069 #endif
1070 		ent = c;
1071 		if (free_ent < maxmaxcode) {
1072 			codetabof(i) = free_ent++;
1073 			/* code -> hashtable */
1074 			htabof(i) = fcode;
1075 		} else {
1076 			in_count = ((long long)inchi<<32|inclo);
1077 			if ((count_long)in_count >=
1078 			    (count_long)checkpoint && block_compress) {
1079 				cl_block(in_count);
1080 			}
1081 		}
1082 	}
1083 
1084 	in_count = ((long long)inchi<<32|inclo);
1085 
1086 	if (ferror(fin) != 0) {
1087 		ioerror();
1088 	}
1089 
1090 	/*
1091 	 * Put out the final code.
1092 	 */
1093 	output((code_int)ent);
1094 #ifdef DEBUG
1095 	out_count++;
1096 #endif
1097 
1098 	output((code_int)-1);
1099 
1100 	/*
1101 	 * Print out stats on stderr
1102 	 */
1103 	if (!quiet) {
1104 #ifdef DEBUG
1105 		(void) fprintf(stderr,
1106 		    "%lld chars in, %lld codes (%lld bytes) out, "
1107 		    "compression factor: ",
1108 		    (count_long)in_count, (count_long)out_count,
1109 		    (count_long) bytes_out);
1110 		prratio(stderr, (count_long)in_count,
1111 		    (count_long)bytes_out);
1112 		(void) fprintf(stderr, "\n");
1113 		(void) fprintf(stderr, "\tCompression as in compact: ");
1114 		prratio(stderr,
1115 		    (count_long)in_count-(count_long)bytes_out,
1116 		    (count_long)in_count);
1117 		(void) fprintf(stderr, "\n");
1118 		(void) fprintf(stderr,
1119 		    "\tLargest code (of last block) was %d"
1120 		    " (%d bits)\n",
1121 		    free_ent - 1, n_bits);
1122 #else /* !DEBUG */
1123 		(void) fprintf(stderr, gettext("Compression: "));
1124 		prratio(stderr,
1125 		    (count_long)in_count-(count_long)bytes_out,
1126 		    (count_long)in_count);
1127 #endif /* DEBUG */
1128 	}
1129 	/* report if no savings */
1130 	if ((count_long)bytes_out > (count_long)in_count) {
1131 		didnt_shrink = 1;
1132 	}
1133 }
1134 
1135 /*
1136  * **************************************************************
1137  * TAG(output)
1138  *
1139  * Output the given code.
1140  * Inputs:
1141  * 	code:	A n_bits-bit integer.  If == -1, then EOF.  This assumes
1142  *		that n_bits = < (long)wordsize - 1.
1143  * Outputs:
1144  * 	Outputs code to the file.
1145  * Assumptions:
1146  *	Chars are 8 bits long.
1147  * Algorithm:
1148  * 	Maintain a BITS character long buffer(so that 8 codes will
1149  * fit in it exactly).  Use the VAX insv instruction to insert each
1150  * code in turn.  When the buffer fills up empty it and start over.
1151  */
1152 
1153 static void
1154 output(code_int code)
1155 {
1156 #ifdef DEBUG
1157 	static int col = 0;
1158 #endif /* DEBUG */
1159 
1160 	int r_off = offset, bits = n_bits;
1161 	char *bp = buf;
1162 
1163 #ifdef DEBUG
1164 	if (verbose)
1165 		(void) fprintf(stderr, "%5d%c", code,
1166 		    (col += 6) >= 74 ? (col = 0, '\n') : ' ');
1167 #endif /* DEBUG */
1168 	if (code >= 0) {
1169 		/*
1170 		 * byte/bit numbering on the VAX is simulated
1171 		 * by the following code
1172 		 */
1173 		/*
1174 		 * Get to the first byte.
1175 		 */
1176 		bp += (r_off >> 3);
1177 		r_off &= 7;
1178 		/*
1179 		 * Since code is always >= 8 bits, only need to mask the first
1180 		 * hunk on the left.
1181 		 */
1182 		*bp = (*bp & rmask[r_off]) | (code << r_off) & lmask[r_off];
1183 		bp++;
1184 		bits -= (8 - r_off);
1185 		code >>= 8 - r_off;
1186 		/*
1187 		 * Get any 8 bit parts in the middle (<=1 for up to 16
1188 		 * bits).
1189 		 */
1190 		if (bits >= 8) {
1191 			*bp++ = code;
1192 			code >>= 8;
1193 			bits -= 8;
1194 		}
1195 		/* Last bits. */
1196 		if (bits)
1197 			*bp = code;
1198 		offset += n_bits;
1199 		if (offset == (n_bits << 3)) {
1200 			bp = buf;
1201 			bits = n_bits;
1202 			bytes_out += bits;
1203 			do {
1204 				if (putc(*bp, outp) == EOF &&
1205 				    ferror(outp)) {
1206 					ioerror();
1207 				}
1208 				bp++;
1209 			} while (--bits);
1210 			offset = 0;
1211 		}
1212 
1213 		/*
1214 		 * If the next entry is going to be too big for the code size,
1215 		 * then increase it, if possible.
1216 		 */
1217 		if (free_ent > maxcode || (clear_flg > 0)) {
1218 			/*
1219 			 * Write the whole buffer, because the input
1220 			 * side won't discover the size increase until
1221 			 * after it has read it.
1222 			 */
1223 			if (offset > 0) {
1224 				if (fwrite(buf, 1, n_bits, outp) != n_bits) {
1225 					longjmp(env, 3);
1226 				}
1227 				bytes_out += n_bits;
1228 			}
1229 			offset = 0;
1230 
1231 			if (clear_flg) {
1232 				maxcode = MAXCODE(n_bits = INIT_BITS);
1233 				clear_flg = 0;
1234 			} else {
1235 				n_bits++;
1236 				if (n_bits == maxbits)
1237 					maxcode = maxmaxcode;
1238 				else
1239 					maxcode = MAXCODE(n_bits);
1240 			}
1241 #ifdef DEBUG
1242 			if (debug) {
1243 				(void) fprintf(stderr,
1244 				    "\nChange to %d bits\n", n_bits);
1245 				col = 0;
1246 			}
1247 #endif /* DEBUG */
1248 		}
1249 	} else {
1250 		/*
1251 		 * At EOF, write the rest of the buffer.
1252 		 */
1253 		if (offset > 0) {
1254 			if (fwrite(buf, 1, (offset + 7) / 8, outp) == 0 &&
1255 			    ferror(outp)) {
1256 				ioerror();
1257 			}
1258 			bytes_out += (offset + 7) / 8;
1259 		}
1260 		offset = 0;
1261 		(void) fflush(outp);
1262 #ifdef DEBUG
1263 		if (verbose)
1264 			(void) fprintf(stderr, "\n");
1265 #endif /* DEBUG */
1266 		if (ferror(outp))
1267 			ioerror();
1268 	}
1269 }
1270 
1271 /*
1272  * Decompress inp to outp.  This routine adapts to the codes in the
1273  * file building the "string" table on-the-fly; requiring no table to
1274  * be stored in the compressed file.  The tables used herein are shared
1275  * with those of the compress() routine.  See the definitions above.
1276  */
1277 
1278 static void
1279 decompress()
1280 {
1281 	char_type *stackp, *stack_lim;
1282 	int finchar;
1283 	code_int code, oldcode, incode;
1284 	FILE *fout = outp;
1285 
1286 	/*
1287 	 * As above, initialize the first 256 entries in the table.
1288 	 */
1289 	maxcode = MAXCODE(n_bits = INIT_BITS);
1290 	for (code = 255; code >= 0; code--) {
1291 		tab_prefixof(code) = 0;
1292 		tab_suffixof(code) = (char_type)code;
1293 	}
1294 	free_ent = ((block_compress) ? FIRST : 256);
1295 
1296 	finchar = oldcode = getcode();
1297 	if (oldcode == -1)	/* EOF already? */
1298 		return;			/* Get out of here */
1299 	/* first code must be 8 bits = char */
1300 	if (putc((char)finchar, outp) == EOF && ferror(outp)) {
1301 		/* Crash if can't write */
1302 		ioerror();
1303 	}
1304 	stackp = de_stack;
1305 	stack_lim = stack_max;
1306 
1307 	while ((code = getcode()) > -1) {
1308 
1309 		if ((code == CLEAR) && block_compress) {
1310 			for (code = 255; code >= 0; code--)
1311 			tab_prefixof(code) = 0;
1312 			clear_flg = 1;
1313 			free_ent = FIRST - 1;
1314 			if ((code = getcode()) == -1)	/* O, untimely death! */
1315 				break;
1316 		}
1317 		incode = code;
1318 		/*
1319 		 * Special case for KwKwK string.
1320 		 */
1321 		if (code >= free_ent) {
1322 			if (stackp < stack_lim) {
1323 				*stackp++ = (char_type) finchar;
1324 				code = oldcode;
1325 			} else {
1326 				/* badness */
1327 				longjmp(env, 2);
1328 			}
1329 		}
1330 
1331 		/*
1332 		 * Generate output characters in reverse order
1333 		 */
1334 		while (code >= 256) {
1335 			if (stackp < stack_lim) {
1336 				*stackp++ = tab_suffixof(code);
1337 				code = tab_prefixof(code);
1338 			} else {
1339 				/* badness */
1340 				longjmp(env, 2);
1341 			}
1342 		}
1343 		*stackp++ = finchar = tab_suffixof(code);
1344 
1345 		/*
1346 		 * And put them out in forward order
1347 		 */
1348 		do {
1349 			stackp--;
1350 			(void) putc(*stackp, fout);
1351 		} while (stackp > de_stack);
1352 
1353 		if (ferror(fout))
1354 			ioerror();
1355 
1356 		/*
1357 		 * Generate the new entry.
1358 		 */
1359 		if ((code = free_ent) < maxmaxcode) {
1360 			tab_prefixof(code) = (unsigned short) oldcode;
1361 			tab_suffixof(code) = (char_type) finchar;
1362 			free_ent = code+1;
1363 		}
1364 		/*
1365 		 * Remember previous code.
1366 		 */
1367 		oldcode = incode;
1368 	}
1369 	(void) fflush(outp);
1370 	if (ferror(outp))
1371 		ioerror();
1372 }
1373 
1374 /*
1375  * **************************************************************
1376  * TAG( getcode )
1377  *
1378  * Read one code from the standard input.  If EOF, return -1.
1379  * Inputs:
1380  * 	inp
1381  * Outputs:
1382  * 	code or -1 is returned.
1383  */
1384 
1385 code_int
1386 getcode() {
1387 	code_int code;
1388 	static int offset = 0, size = 0;
1389 	static char_type buf[BITS];
1390 	int r_off, bits;
1391 	char_type *bp = buf;
1392 
1393 	if (clear_flg > 0 || offset >= size || free_ent > maxcode) {
1394 		/*
1395 		 * If the next entry will be too big for the current code
1396 		 * size, then we must increase the size.  This implies reading
1397 		 * a new buffer full, too.
1398 		 */
1399 		if (free_ent > maxcode) {
1400 			n_bits++;
1401 			if (n_bits == maxbits)
1402 				/* won't get any bigger now */
1403 				maxcode = maxmaxcode;
1404 			else
1405 				maxcode = MAXCODE(n_bits);
1406 		}
1407 		if (clear_flg > 0) {
1408 			maxcode = MAXCODE(n_bits = INIT_BITS);
1409 			clear_flg = 0;
1410 		}
1411 		size = fread(buf, 1, n_bits, inp);
1412 
1413 		if (size <= 0) {
1414 			if (feof(inp)) {
1415 				/* end of file */
1416 				return (-1);
1417 			} else if (ferror(inp)) {
1418 				ioerror();
1419 			}
1420 		}
1421 
1422 		offset = 0;
1423 		/* Round size down to integral number of codes */
1424 		size = (size << 3) - (n_bits - 1);
1425 	}
1426 	r_off = offset;
1427 	bits = n_bits;
1428 	/*
1429 	 * Get to the first byte.
1430 	 */
1431 	bp += (r_off >> 3);
1432 	r_off &= 7;
1433 	/* Get first part (low order bits) */
1434 	code = (*bp++ >> r_off);
1435 	bits -= (8 - r_off);
1436 	r_off = 8 - r_off;		/* now, offset into code word */
1437 	/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
1438 	if (bits >= 8) {
1439 		code |= *bp++ << r_off;
1440 		r_off += 8;
1441 		bits -= 8;
1442 	}
1443 	/* high order bits. */
1444 	code |= (*bp & rmask[bits]) << r_off;
1445 	offset += n_bits;
1446 
1447 	return (code);
1448 }
1449 
1450 #ifdef DEBUG
1451 static void
1452 printcodes()
1453 {
1454 	/*
1455 	 * Just print out codes from input file.  For debugging.
1456 	 */
1457 	code_int code;
1458 	int col = 0, bits;
1459 
1460 	bits = n_bits = INIT_BITS;
1461 	maxcode = MAXCODE(n_bits);
1462 	free_ent = ((block_compress) ? FIRST : 256);
1463 	while ((code = getcode()) >= 0) {
1464 		if ((code == CLEAR) && block_compress) {
1465 			free_ent = FIRST - 1;
1466 			clear_flg = 1;
1467 		} else if (free_ent < maxmaxcode)
1468 			free_ent++;
1469 		if (bits != n_bits) {
1470 			(void) fprintf(stderr, "\nChange to %d bits\n", n_bits);
1471 			bits = n_bits;
1472 			col = 0;
1473 		}
1474 		(void) fprintf(stderr, "%5d%c",
1475 		    code, (col += 6) >= 74 ? (col = 0, '\n') : ' ');
1476 	}
1477 	(void) putc('\n', stderr);
1478 }
1479 
1480 #endif /* DEBUG */
1481 
1482 #ifdef DEBUG
1483 static void
1484 dump_tab()	/* dump string table */
1485 {
1486 	int i, first;
1487 	int ent;
1488 	int stack_top = STACK_SIZE;
1489 	int c;
1490 
1491 	if (do_decomp == 0) {	/* compressing */
1492 		int flag = 1;
1493 
1494 		for (i = 0; i < hsize; i++) {	/* build sort pointers */
1495 			if ((long)htabof(i) >= 0) {
1496 				sorttab[codetabof(i)] = i;
1497 			}
1498 		}
1499 		first = block_compress ? FIRST : 256;
1500 		for (i = first; i < free_ent; i++) {
1501 			(void) fprintf(stderr, "%5d: \"", i);
1502 			de_stack[--stack_top] = '\n';
1503 			de_stack[--stack_top] = '"';
1504 			stack_top =
1505 			    in_stack((htabof(sorttab[i]) >> maxbits) & 0xff,
1506 			    stack_top);
1507 			for (ent = htabof(sorttab[i]) & ((1 << maxbits) -1);
1508 			    ent > 256;
1509 			    ent = htabof(sorttab[ent]) & ((1<<maxbits)-1)) {
1510 				stack_top = in_stack(
1511 				    htabof(sorttab[ent]) >> maxbits,
1512 				    stack_top);
1513 			}
1514 			stack_top = in_stack(ent, stack_top);
1515 			(void) fwrite(&de_stack[stack_top], 1,
1516 			    STACK_SIZE - stack_top, stderr);
1517 			stack_top = STACK_SIZE;
1518 		}
1519 	} else if (!debug) {	/* decompressing */
1520 
1521 		for (i = 0; i < free_ent; i++) {
1522 			ent = i;
1523 			c = tab_suffixof(ent);
1524 			if (isascii(c) && isprint(c))
1525 				(void) fprintf(stderr, "%5d: %5d/'%c'  \"",
1526 				    ent, tab_prefixof(ent), c);
1527 			else
1528 				(void) fprintf(stderr, "%5d: %5d/\\%03o \"",
1529 				    ent, tab_prefixof(ent), c);
1530 			de_stack[--stack_top] = '\n';
1531 			de_stack[--stack_top] = '"';
1532 			for (; ent != NULL;
1533 			    ent = (ent >= FIRST ? tab_prefixof(ent) :
1534 			    NULL)) {
1535 				stack_top = in_stack(tab_suffixof(ent),
1536 				    stack_top);
1537 			}
1538 			(void) fwrite(&de_stack[stack_top], 1,
1539 			    STACK_SIZE - stack_top, stderr);
1540 			stack_top = STACK_SIZE;
1541 		}
1542 	}
1543 }
1544 
1545 #endif /* DEBUG */
1546 #ifdef DEBUG
1547 static int
1548 in_stack(int c, int stack_top)
1549 {
1550 	if ((isascii(c) && isprint(c) && c != '\\') || c == ' ') {
1551 		de_stack[--stack_top] = c;
1552 	} else {
1553 		switch (c) {
1554 		case '\n': de_stack[--stack_top] = 'n'; break;
1555 		case '\t': de_stack[--stack_top] = 't'; break;
1556 		case '\b': de_stack[--stack_top] = 'b'; break;
1557 		case '\f': de_stack[--stack_top] = 'f'; break;
1558 		case '\r': de_stack[--stack_top] = 'r'; break;
1559 		case '\\': de_stack[--stack_top] = '\\'; break;
1560 		default:
1561 			de_stack[--stack_top] = '0' + c % 8;
1562 			de_stack[--stack_top] = '0' + (c / 8) % 8;
1563 			de_stack[--stack_top] = '0' + c / 64;
1564 			break;
1565 		}
1566 		de_stack[--stack_top] = '\\';
1567 	}
1568 	return (stack_top);
1569 }
1570 
1571 #endif /* DEBUG */
1572 static void
1573 ioerror()
1574 {
1575 	longjmp(env, 1);
1576 }
1577 
1578 static void
1579 copystat(char *ifname, struct stat *ifstat, char *ofname)
1580 {
1581 	mode_t mode;
1582 	struct utimbuf timep;
1583 	acl_t *aclp = NULL;
1584 	int error;
1585 	int sattr_exist = 0;
1586 	int xattr_exist = 0;
1587 
1588 	if (pathconf(ifname, _PC_XATTR_EXISTS) == 1)
1589 		xattr_exist = 1;
1590 	if (saflg && sysattr_support(ifname, _PC_SATTR_EXISTS) == 1)
1591 		sattr_exist = 1;
1592 
1593 	if (fclose(outp)) {
1594 		perror(ofname);
1595 		if (!quiet) {
1596 			(void) fprintf(stderr, gettext(" -- file unchanged"));
1597 			newline_needed = 1;
1598 		}
1599 		perm_stat = 1;
1600 	} else if (ifstat == NULL) {	/* Get stat on input file */
1601 		perror(ifname);
1602 		return;
1603 	} else if ((ifstat->st_mode &
1604 	    S_IFMT /* 0170000 */) != S_IFREG /* 0100000 */) {
1605 		if (quiet) {
1606 			(void) fprintf(stderr, "%s: ", ifname);
1607 		}
1608 		(void) fprintf(stderr, gettext(
1609 		    " -- not a regular file: unchanged"));
1610 		newline_needed = 1;
1611 		perm_stat = 1;
1612 	} else if (ifstat->st_nlink > 1) {
1613 		if (quiet) {
1614 			(void) fprintf(stderr, "%s: ", ifname);
1615 		}
1616 		(void) fprintf(stderr, gettext(
1617 		    " -- has %d other links: unchanged"),
1618 		    (uint_t)ifstat->st_nlink - 1);
1619 		newline_needed = 1;
1620 		perm_stat = 1;
1621 	} else if (didnt_shrink && !force) {
1622 		/* No compression: remove file.Z */
1623 		if (!quiet) {
1624 			(void) fprintf(stderr, gettext(
1625 			    " -- file unchanged"));
1626 			newline_needed = 1;
1627 		}
1628 	} else 	if ((xattr_exist || sattr_exist) &&
1629 	    (mv_xattrs(progname, ifname, ofname, sattr_exist, 0)
1630 	    != 0)) {
1631 		(void) fprintf(stderr, gettext(
1632 		    "%s: -- cannot preserve extended attributes or "
1633 		    "system attributes, file unchanged"), ifname);
1634 		newline_needed = 1;
1635 		/* Move attributes back ... */
1636 		xattr_exist = 0;
1637 		sattr_exist = 0;
1638 		if (pathconf(ofname, _PC_XATTR_EXISTS) == 1)
1639 			xattr_exist = 1;
1640 		if (saflg && sysattr_support(ofname, _PC_SATTR_EXISTS) == 1)
1641 			sattr_exist = 1;
1642 		if (sattr_exist || xattr_exist)
1643 			(void) mv_xattrs(progname, ofname, ifname,
1644 			    sattr_exist, 1);
1645 		perm_stat = 1;
1646 	} else { /* ***** Successful Compression ***** */
1647 		mode = ifstat->st_mode & 07777;
1648 		if (chmod(ofname, mode)) {	 /* Copy modes */
1649 			if (errno == EPERM) {
1650 				(void) fprintf(stderr,
1651 				    gettext("failed to chmod %s"
1652 				    "- permisssion denied\n"), ofname);
1653 			}
1654 			perror(ofname);
1655 		}
1656 		error = acl_get(ifname, ACL_NO_TRIVIAL, &aclp);
1657 		if (error != 0) {
1658 			(void) fprintf(stderr, gettext(
1659 			    "%s: failed to retrieve acl : %s\n"),
1660 			    ifname, acl_strerror(error));
1661 			perm_stat = 1;
1662 		}
1663 		if (aclp && (acl_set(ofname, aclp) < 0)) {
1664 			(void) fprintf(stderr,
1665 			    gettext("%s: failed to set acl "
1666 			    "entries\n"), ofname);
1667 			perm_stat = 1;
1668 		}
1669 		if (aclp) {
1670 			acl_free(aclp);
1671 			aclp = NULL;
1672 		}
1673 
1674 		/* Copy ownership */
1675 		(void) chown(ofname, ifstat->st_uid, ifstat->st_gid);
1676 		timep.actime = ifstat->st_atime;
1677 		timep.modtime = ifstat->st_mtime;
1678 		/* Update last accessed and modified times */
1679 		(void) utime(ofname, &timep);
1680 		if (unlink(ifname)) { /* Remove input file */
1681 			if (errno == EPERM) {
1682 				(void) fprintf(stderr,
1683 				    gettext("failed to remove %s"
1684 				    "- permisssion denied\n"), ifname);
1685 			}
1686 			perror(ifname);
1687 		}
1688 		if (!quiet) {
1689 			(void) fprintf(stderr, gettext(
1690 			    " -- replaced with %s"), ofname);
1691 			newline_needed = 1;
1692 		}
1693 		return;		/* Successful return */
1694 	}
1695 
1696 	/* Unsuccessful return -- one of the tests failed */
1697 	if (ofname[0] != '\0') {
1698 		if (unlink(ofname)) {
1699 			if (errno == EPERM) {
1700 				(void) fprintf(stderr,
1701 				    gettext("failed to remove %s"
1702 				    "- permisssion denied\n"), ifname);
1703 			}
1704 			perror(ofname);
1705 		}
1706 
1707 		ofname[0] = '\0';
1708 	}
1709 }
1710 
1711 static void
1712 onintr()
1713 {
1714 	if (!precious && !use_stdout && ofname[0] != '\0')
1715 		(void) unlink(ofname);
1716 	exit(1);
1717 }
1718 
1719 static void
1720 oops()	/* wild pointer -- assume bad input */
1721 {
1722 	if (do_decomp) {
1723 		(void) fprintf(stderr, gettext("uncompress: corrupt input\n"));
1724 	}
1725 
1726 	if (!use_stdout && ofname[0] != '\0') {
1727 		(void) unlink(ofname);
1728 	}
1729 
1730 	exit(1);
1731 }
1732 
1733 static void
1734 cl_block(count_long in_count)	/* table clear for block compress */
1735 {
1736 	count_long rat;
1737 
1738 	checkpoint = (count_long)in_count + (count_long)CHECK_GAP;
1739 #ifdef DEBUG
1740 	if (debug) {
1741 		(void) fprintf(stderr, "count: %lld, ratio: ",
1742 		    (count_long)in_count);
1743 		prratio(stderr, (count_long)in_count, (count_long)bytes_out);
1744 		(void) fprintf(stderr, "\n");
1745 	}
1746 #endif /* DEBUG */
1747 
1748 	/* shift will overflow */
1749 	if ((count_long)in_count > 0x007fffffffffffffLL) {
1750 		rat = (count_long)bytes_out >> 8;
1751 		if (rat == 0) {		/* Don't divide by zero */
1752 			rat = 0x7fffffffffffffffLL;
1753 		} else {
1754 			rat = (count_long)in_count / (count_long)rat;
1755 		}
1756 	} else {
1757 		/* 8 fractional bits */
1758 		rat = ((count_long)in_count << 8) /(count_long)bytes_out;
1759 	}
1760 	if (rat > ratio) {
1761 		ratio = rat;
1762 	} else {
1763 		ratio = 0;
1764 #ifdef DEBUG
1765 		if (verbose)
1766 			dump_tab();	/* dump string table */
1767 #endif
1768 		cl_hash((count_int) hsize);
1769 		free_ent = FIRST;
1770 		clear_flg = 1;
1771 		output((code_int) CLEAR);
1772 #ifdef DEBUG
1773 		if (debug)
1774 			(void) fprintf(stderr, "clear\n");
1775 #endif /* DEBUG */
1776 	}
1777 }
1778 
1779 static void
1780 cl_hash(count_int hsize)		/* reset code table */
1781 {
1782 	count_int *htab_p = htab+hsize;
1783 	long i;
1784 	long m1 = -1;
1785 
1786 	i = hsize - 16;
1787 	do {				/* might use Sys V memset(3) here */
1788 		*(htab_p-16) = m1;
1789 		*(htab_p-15) = m1;
1790 		*(htab_p-14) = m1;
1791 		*(htab_p-13) = m1;
1792 		*(htab_p-12) = m1;
1793 		*(htab_p-11) = m1;
1794 		*(htab_p-10) = m1;
1795 		*(htab_p-9) = m1;
1796 		*(htab_p-8) = m1;
1797 		*(htab_p-7) = m1;
1798 		*(htab_p-6) = m1;
1799 		*(htab_p-5) = m1;
1800 		*(htab_p-4) = m1;
1801 		*(htab_p-3) = m1;
1802 		*(htab_p-2) = m1;
1803 		*(htab_p-1) = m1;
1804 		htab_p -= 16;
1805 	} while ((i -= 16) >= 0);
1806 		for (i += 16; i > 0; i--)
1807 			*--htab_p = m1;
1808 }
1809 
1810 static void
1811 prratio(FILE *stream, count_long num, count_long den)
1812 {
1813 	int q;  /* store percentage */
1814 
1815 	q = (int)(10000LL * (count_long)num / (count_long)den);
1816 	if (q < 0) {
1817 		(void) putc('-', stream);
1818 		q = -q;
1819 	}
1820 	(void) fprintf(stream, "%d%s%02d%%", q / 100,
1821 	    localeconv()->decimal_point, q % 100);
1822 }
1823 
1824 static void
1825 version()
1826 {
1827 	(void) fprintf(stderr, "%s, Berkeley 5.9 5/11/86\n", rcs_ident);
1828 	(void) fprintf(stderr, "Options: ");
1829 #ifdef DEBUG
1830 	(void) fprintf(stderr, "DEBUG, ");
1831 #endif
1832 	(void) fprintf(stderr, "BITS = %d\n", BITS);
1833 }
1834 
1835 static void
1836 Usage()
1837 {
1838 #ifdef DEBUG
1839 	(void) fprintf(stderr,
1840 	"Usage: compress [-dDVfc/] [-b maxbits] [file ...]\n");
1841 #else
1842 	if (strcmp(progname, "compress") == 0) {
1843 		(void) fprintf(stderr,
1844 		    gettext(
1845 		    "Usage: compress [-fv/] [-b maxbits] [file ...]\n"\
1846 		    "       compress c [-fv] [-b maxbits] [file]\n"));
1847 	} else if (strcmp(progname, "uncompress") == 0)
1848 		(void) fprintf(stderr, gettext(
1849 		    "Usage: uncompress [-fv] [-c || -/] [file ...]\n"));
1850 	else if (strcmp(progname, "zcat") == 0)
1851 		(void) fprintf(stderr, gettext("Usage: zcat [file ...]\n"));
1852 
1853 #endif /* DEBUG */
1854 }
1855 
1856 static char *
1857 local_basename(char *path)
1858 {
1859 	char *p;
1860 	char *ret = (char *)path;
1861 
1862 	while ((p = (char *)strpbrk(ret, "/")) != NULL)
1863 		ret = p + 1;
1864 	return (ret);
1865 }
1866 
1867 static int
1868 addDotZ(char *fn, size_t fnsize)
1869 {
1870 	char *fn_dup;
1871 	char *dir;
1872 	long int max_name;
1873 	long int max_path;
1874 
1875 	fn_dup = strdup(fn);
1876 	dir = dirname(fn_dup);
1877 	max_name = pathconf(dir, _PC_NAME_MAX);
1878 	max_path = pathconf(dir, _PC_PATH_MAX);
1879 	free(fn_dup);
1880 
1881 	/* Check for component length too long */
1882 
1883 	if ((strlen(local_basename(fn)) + 2) > (size_t)max_name) {
1884 		(void) fprintf(stderr,
1885 		    gettext("%s: filename too long to tack on .Z:"
1886 		    " %s\n"), progname, fn);
1887 		return (-1);
1888 	}
1889 
1890 	/* Check for path length too long */
1891 
1892 	if ((strlen(fn) + 2) > (size_t)max_path - 1) {
1893 		(void) fprintf(stderr,
1894 		    gettext("%s: Pathname too long to tack on .Z:"
1895 		    " %s\n"), progname, fn);
1896 		return (-1);
1897 	}
1898 
1899 	if (strlcat(fn, ".Z", fnsize) >= fnsize) {
1900 		(void) fprintf(stderr,
1901 		    gettext("%s: Buffer overflow adding .Z to %s\n"),
1902 		    progname, fn);
1903 		return (-1);
1904 	}
1905 
1906 	return (0);
1907 }
1908