xref: /freebsd/bin/pax/pat_rep.c (revision ec965063070e5753c166cf592c9336444b74720a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992 Keith Muller.
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Keith Muller of the University of California, San Diego.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)pat_rep.c	8.2 (Berkeley) 4/18/94";
39 #endif
40 #endif /* not lint */
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/types.h>
45 #include <sys/stat.h>
46 #include <stdio.h>
47 #include <string.h>
48 #include <stdlib.h>
49 #include <regex.h>
50 #include "pax.h"
51 #include "pat_rep.h"
52 #include "extern.h"
53 
54 /*
55  * routines to handle pattern matching, name modification (regular expression
56  * substitution and interactive renames), and destination name modification for
57  * copy (-rw). Both file name and link names are adjusted as required in these
58  * routines.
59  */
60 
61 #define MAXSUBEXP	10		/* max subexpressions, DO NOT CHANGE */
62 static PATTERN *pathead = NULL;		/* file pattern match list head */
63 static PATTERN *pattail = NULL;		/* file pattern match list tail */
64 static REPLACE *rephead = NULL;		/* replacement string list head */
65 static REPLACE *reptail = NULL;		/* replacement string list tail */
66 
67 static int rep_name(char *, int *, int);
68 static int tty_rename(ARCHD *);
69 static int fix_path(char *, int *, char *, int);
70 static int fn_match(char *, char *, char **);
71 static char * range_match(char *, int);
72 static int resub(regex_t *, regmatch_t *, char *, char *, char *, char *);
73 
74 /*
75  * rep_add()
76  *	parses the -s replacement string; compiles the regular expression
77  *	and stores the compiled value and it's replacement string together in
78  *	replacement string list. Input to this function is of the form:
79  *		/old/new/pg
80  *	The first char in the string specifies the delimiter used by this
81  *	replacement string. "Old" is a regular expression in "ed" format which
82  *	is compiled by regcomp() and is applied to filenames. "new" is the
83  *	substitution string; p and g are options flags for printing and global
84  *	replacement (over the single filename)
85  * Return:
86  *	0 if a proper replacement string and regular expression was added to
87  *	the list of replacement patterns; -1 otherwise.
88  */
89 
90 int
91 rep_add(char *str)
92 {
93 	char *pt1;
94 	char *pt2;
95 	REPLACE *rep;
96 	int res;
97 	char rebuf[BUFSIZ];
98 
99 	/*
100 	 * throw out the bad parameters
101 	 */
102 	if ((str == NULL) || (*str == '\0')) {
103 		paxwarn(1, "Empty replacement string");
104 		return(-1);
105 	}
106 
107 	/*
108 	 * first character in the string specifies what the delimiter is for
109 	 * this expression
110 	 */
111 	if ((pt1 = strchr(str+1, *str)) == NULL) {
112 		paxwarn(1, "Invalid replacement string %s", str);
113 		return(-1);
114 	}
115 
116 	/*
117 	 * allocate space for the node that handles this replacement pattern
118 	 * and split out the regular expression and try to compile it
119 	 */
120 	if ((rep = (REPLACE *)malloc(sizeof(REPLACE))) == NULL) {
121 		paxwarn(1, "Unable to allocate memory for replacement string");
122 		return(-1);
123 	}
124 
125 	*pt1 = '\0';
126 	if ((res = regcomp(&(rep->rcmp), str+1, 0)) != 0) {
127 		regerror(res, &(rep->rcmp), rebuf, sizeof(rebuf));
128 		paxwarn(1, "%s while compiling regular expression %s", rebuf, str);
129 		free(rep);
130 		return(-1);
131 	}
132 
133 	/*
134 	 * put the delimiter back in case we need an error message and
135 	 * locate the delimiter at the end of the replacement string
136 	 * we then point the node at the new substitution string
137 	 */
138 	*pt1++ = *str;
139 	if ((pt2 = strchr(pt1, *str)) == NULL) {
140 		regfree(&rep->rcmp);
141 		free(rep);
142 		paxwarn(1, "Invalid replacement string %s", str);
143 		return(-1);
144 	}
145 
146 	*pt2 = '\0';
147 	rep->nstr = pt1;
148 	pt1 = pt2++;
149 	rep->flgs = 0;
150 
151 	/*
152 	 * set the options if any
153 	 */
154 	while (*pt2 != '\0') {
155 		switch(*pt2) {
156 		case 'g':
157 		case 'G':
158 			rep->flgs  |= GLOB;
159 			break;
160 		case 'p':
161 		case 'P':
162 			rep->flgs  |= PRNT;
163 			break;
164 		default:
165 			regfree(&rep->rcmp);
166 			free(rep);
167 			*pt1 = *str;
168 			paxwarn(1, "Invalid replacement string option %s", str);
169 			return(-1);
170 		}
171 		++pt2;
172 	}
173 
174 	/*
175 	 * all done, link it in at the end
176 	 */
177 	rep->fow = NULL;
178 	if (rephead == NULL) {
179 		reptail = rephead = rep;
180 		return(0);
181 	}
182 	reptail->fow = rep;
183 	reptail = rep;
184 	return(0);
185 }
186 
187 /*
188  * pat_add()
189  *	add a pattern match to the pattern match list. Pattern matches are used
190  *	to select which archive members are extracted. (They appear as
191  *	arguments to pax in the list and read modes). If no patterns are
192  *	supplied to pax, all members in the archive will be selected (and the
193  *	pattern match list is empty).
194  * Return:
195  *	0 if the pattern was added to the list, -1 otherwise
196  */
197 
198 int
199 pat_add(char *str, char *chdnam)
200 {
201 	PATTERN *pt;
202 
203 	/*
204 	 * throw out the junk
205 	 */
206 	if ((str == NULL) || (*str == '\0')) {
207 		paxwarn(1, "Empty pattern string");
208 		return(-1);
209 	}
210 
211 	/*
212 	 * allocate space for the pattern and store the pattern. the pattern is
213 	 * part of argv so do not bother to copy it, just point at it. Add the
214 	 * node to the end of the pattern list
215 	 */
216 	if ((pt = (PATTERN *)malloc(sizeof(PATTERN))) == NULL) {
217 		paxwarn(1, "Unable to allocate memory for pattern string");
218 		return(-1);
219 	}
220 
221 	pt->pstr = str;
222 	pt->pend = NULL;
223 	pt->plen = strlen(str);
224 	pt->fow = NULL;
225 	pt->flgs = 0;
226 	pt->chdname = chdnam;
227 
228 	if (pathead == NULL) {
229 		pattail = pathead = pt;
230 		return(0);
231 	}
232 	pattail->fow = pt;
233 	pattail = pt;
234 	return(0);
235 }
236 
237 /*
238  * pat_chk()
239  *	complain if any the user supplied pattern did not result in a match to
240  *	a selected archive member.
241  */
242 
243 void
244 pat_chk(void)
245 {
246 	PATTERN *pt;
247 	int wban = 0;
248 
249 	/*
250 	 * walk down the list checking the flags to make sure MTCH was set,
251 	 * if not complain
252 	 */
253 	for (pt = pathead; pt != NULL; pt = pt->fow) {
254 		if (pt->flgs & MTCH)
255 			continue;
256 		if (!wban) {
257 			paxwarn(1, "WARNING! These patterns were not matched:");
258 			++wban;
259 		}
260 		(void)fprintf(stderr, "%s\n", pt->pstr);
261 	}
262 }
263 
264 /*
265  * pat_sel()
266  *	the archive member which matches a pattern was selected. Mark the
267  *	pattern as having selected an archive member. arcn->pat points at the
268  *	pattern that was matched. arcn->pat is set in pat_match()
269  *
270  *	NOTE: When the -c option is used, we are called when there was no match
271  *	by pat_match() (that means we did match before the inverted sense of
272  *	the logic). Now this seems really strange at first, but with -c  we
273  *	need to keep track of those patterns that cause an archive member to NOT
274  *	be selected (it found an archive member with a specified pattern)
275  * Return:
276  *	0 if the pattern pointed at by arcn->pat was tagged as creating a
277  *	match, -1 otherwise.
278  */
279 
280 int
281 pat_sel(ARCHD *arcn)
282 {
283 	PATTERN *pt;
284 	PATTERN **ppt;
285 	int len;
286 
287 	/*
288 	 * if no patterns just return
289 	 */
290 	if ((pathead == NULL) || ((pt = arcn->pat) == NULL))
291 		return(0);
292 
293 	/*
294 	 * when we are NOT limited to a single match per pattern mark the
295 	 * pattern and return
296 	 */
297 	if (!nflag) {
298 		pt->flgs |= MTCH;
299 		return(0);
300 	}
301 
302 	/*
303 	 * we reach this point only when we allow a single selected match per
304 	 * pattern, if the pattern matches a directory and we do not have -d
305 	 * (dflag) we are done with this pattern. We may also be handed a file
306 	 * in the subtree of a directory. in that case when we are operating
307 	 * with -d, this pattern was already selected and we are done
308 	 */
309 	if (pt->flgs & DIR_MTCH)
310 		return(0);
311 
312 	if (!dflag && ((pt->pend != NULL) || (arcn->type == PAX_DIR))) {
313 		/*
314 		 * ok we matched a directory and we are allowing
315 		 * subtree matches but because of the -n only its children will
316 		 * match. This is tagged as a DIR_MTCH type.
317 		 * WATCH IT, the code assumes that pt->pend points
318 		 * into arcn->name and arcn->name has not been modified.
319 		 * If not we will have a big mess. Yup this is another kludge
320 		 */
321 
322 		/*
323 		 * if this was a prefix match, remove trailing part of path
324 		 * so we can copy it. Future matches will be exact prefix match
325 		 */
326 		if (pt->pend != NULL)
327 			*pt->pend = '\0';
328 
329 		if ((pt->pstr = strdup(arcn->name)) == NULL) {
330 			paxwarn(1, "Pattern select out of memory");
331 			if (pt->pend != NULL)
332 				*pt->pend = '/';
333 			pt->pend = NULL;
334 			return(-1);
335 		}
336 
337 		/*
338 		 * put the trailing / back in the source string
339 		 */
340 		if (pt->pend != NULL) {
341 			*pt->pend = '/';
342 			pt->pend = NULL;
343 		}
344 		pt->plen = strlen(pt->pstr);
345 
346 		/*
347 		 * strip off any trailing /, this should really never happen
348 		 */
349 		len = pt->plen - 1;
350 		if (*(pt->pstr + len) == '/') {
351 			*(pt->pstr + len) = '\0';
352 			pt->plen = len;
353 		}
354 		pt->flgs = DIR_MTCH | MTCH;
355 		arcn->pat = pt;
356 		return(0);
357 	}
358 
359 	/*
360 	 * we are then done with this pattern, so we delete it from the list
361 	 * because it can never be used for another match.
362 	 * Seems kind of strange to do for a -c, but the pax spec is really
363 	 * vague on the interaction of -c -n and -d. We assume that when -c
364 	 * and the pattern rejects a member (i.e. it matched it) it is done.
365 	 * In effect we place the order of the flags as having -c last.
366 	 */
367 	pt = pathead;
368 	ppt = &pathead;
369 	while ((pt != NULL) && (pt != arcn->pat)) {
370 		ppt = &(pt->fow);
371 		pt = pt->fow;
372 	}
373 
374 	if (pt == NULL) {
375 		/*
376 		 * should never happen....
377 		 */
378 		paxwarn(1, "Pattern list inconsistent");
379 		return(-1);
380 	}
381 	*ppt = pt->fow;
382 	free(pt);
383 	arcn->pat = NULL;
384 	return(0);
385 }
386 
387 /*
388  * pat_match()
389  *	see if this archive member matches any supplied pattern, if a match
390  *	is found, arcn->pat is set to point at the potential pattern. Later if
391  *	this archive member is "selected" we process and mark the pattern as
392  *	one which matched a selected archive member (see pat_sel())
393  * Return:
394  *	0 if this archive member should be processed, 1 if it should be
395  *	skipped and -1 if we are done with all patterns (and pax should quit
396  *	looking for more members)
397  */
398 
399 int
400 pat_match(ARCHD *arcn)
401 {
402 	PATTERN *pt;
403 
404 	arcn->pat = NULL;
405 
406 	/*
407 	 * if there are no more patterns and we have -n (and not -c) we are
408 	 * done. otherwise with no patterns to match, matches all
409 	 */
410 	if (pathead == NULL) {
411 		if (nflag && !cflag)
412 			return(-1);
413 		return(0);
414 	}
415 
416 	/*
417 	 * have to search down the list one at a time looking for a match.
418 	 */
419 	pt = pathead;
420 	while (pt != NULL) {
421 		/*
422 		 * check for a file name match unless we have DIR_MTCH set in
423 		 * this pattern then we want a prefix match
424 		 */
425 		if (pt->flgs & DIR_MTCH) {
426 			/*
427 			 * this pattern was matched before to a directory
428 			 * as we must have -n set for this (but not -d). We can
429 			 * only match CHILDREN of that directory so we must use
430 			 * an exact prefix match (no wildcards).
431 			 */
432 			if ((arcn->name[pt->plen] == '/') &&
433 			    (strncmp(pt->pstr, arcn->name, pt->plen) == 0))
434 				break;
435 		} else if (fn_match(pt->pstr, arcn->name, &pt->pend) == 0)
436 			break;
437 		pt = pt->fow;
438 	}
439 
440 	/*
441 	 * return the result, remember that cflag (-c) inverts the sense of a
442 	 * match
443 	 */
444 	if (pt == NULL)
445 		return(cflag ? 0 : 1);
446 
447 	/*
448 	 * We had a match, now when we invert the sense (-c) we reject this
449 	 * member. However we have to tag the pattern a being successful, (in a
450 	 * match, not in selecting an archive member) so we call pat_sel() here.
451 	 */
452 	arcn->pat = pt;
453 	if (!cflag)
454 		return(0);
455 
456 	if (pat_sel(arcn) < 0)
457 		return(-1);
458 	arcn->pat = NULL;
459 	return(1);
460 }
461 
462 /*
463  * fn_match()
464  * Return:
465  *	0 if this archive member should be processed, 1 if it should be
466  *	skipped and -1 if we are done with all patterns (and pax should quit
467  *	looking for more members)
468  *	Note: *pend may be changed to show where the prefix ends.
469  */
470 
471 static int
472 fn_match(char *pattern, char *string, char **pend)
473 {
474 	char c;
475 	char test;
476 
477 	*pend = NULL;
478 	for (;;) {
479 		switch (c = *pattern++) {
480 		case '\0':
481 			/*
482 			 * Ok we found an exact match
483 			 */
484 			if (*string == '\0')
485 				return(0);
486 
487 			/*
488 			 * Check if it is a prefix match
489 			 */
490 			if ((dflag == 1) || (*string != '/'))
491 				return(-1);
492 
493 			/*
494 			 * It is a prefix match, remember where the trailing
495 			 * / is located
496 			 */
497 			*pend = string;
498 			return(0);
499 		case '?':
500 			if ((test = *string++) == '\0')
501 				return (-1);
502 			break;
503 		case '*':
504 			c = *pattern;
505 			/*
506 			 * Collapse multiple *'s.
507 			 */
508 			while (c == '*')
509 				c = *++pattern;
510 
511 			/*
512 			 * Optimized hack for pattern with a * at the end
513 			 */
514 			if (c == '\0')
515 				return (0);
516 
517 			/*
518 			 * General case, use recursion.
519 			 */
520 			while ((test = *string) != '\0') {
521 				if (!fn_match(pattern, string, pend))
522 					return (0);
523 				++string;
524 			}
525 			return (-1);
526 		case '[':
527 			/*
528 			 * range match
529 			 */
530 			if (((test = *string++) == '\0') ||
531 			    ((pattern = range_match(pattern, test)) == NULL))
532 				return (-1);
533 			break;
534 		case '\\':
535 		default:
536 			if (c != *string++)
537 				return (-1);
538 			break;
539 		}
540 	}
541 	/* NOTREACHED */
542 }
543 
544 static char *
545 range_match(char *pattern, int test)
546 {
547 	char c;
548 	char c2;
549 	int negate;
550 	int ok = 0;
551 
552 	if ((negate = (*pattern == '!')) != 0)
553 		++pattern;
554 
555 	while ((c = *pattern++) != ']') {
556 		/*
557 		 * Illegal pattern
558 		 */
559 		if (c == '\0')
560 			return (NULL);
561 
562 		if ((*pattern == '-') && ((c2 = pattern[1]) != '\0') &&
563 		    (c2 != ']')) {
564 			if ((c <= test) && (test <= c2))
565 				ok = 1;
566 			pattern += 2;
567 		} else if (c == test)
568 			ok = 1;
569 	}
570 	return (ok == negate ? NULL : pattern);
571 }
572 
573 /*
574  * mod_name()
575  *	modify a selected file name. first attempt to apply replacement string
576  *	expressions, then apply interactive file rename. We apply replacement
577  *	string expressions to both filenames and file links (if we didn't the
578  *	links would point to the wrong place, and we could never be able to
579  *	move an archive that has a file link in it). When we rename files
580  *	interactively, we store that mapping (old name to user input name) so
581  *	if we spot any file links to the old file name in the future, we will
582  *	know exactly how to fix the file link.
583  * Return:
584  *	0 continue to  process file, 1 skip this file, -1 pax is finished
585  */
586 
587 int
588 mod_name(ARCHD *arcn)
589 {
590 	int res = 0;
591 
592 	/*
593 	 * Strip off leading '/' if appropriate.
594 	 * Currently, this option is only set for the tar format.
595 	 */
596 	if (rmleadslash && arcn->name[0] == '/') {
597 		if (arcn->name[1] == '\0') {
598 			arcn->name[0] = '.';
599 		} else {
600 			(void)memmove(arcn->name, &arcn->name[1],
601 			    strlen(arcn->name));
602 			arcn->nlen--;
603 		}
604 		if (rmleadslash < 2) {
605 			rmleadslash = 2;
606 			paxwarn(0, "Removing leading / from absolute path names in the archive");
607 		}
608 	}
609 	if (rmleadslash && arcn->ln_name[0] == '/' &&
610 	    (arcn->type == PAX_HLK || arcn->type == PAX_HRG)) {
611 		if (arcn->ln_name[1] == '\0') {
612 			arcn->ln_name[0] = '.';
613 		} else {
614 			(void)memmove(arcn->ln_name, &arcn->ln_name[1],
615 			    strlen(arcn->ln_name));
616 			arcn->ln_nlen--;
617 		}
618 		if (rmleadslash < 2) {
619 			rmleadslash = 2;
620 			paxwarn(0, "Removing leading / from absolute path names in the archive");
621 		}
622 	}
623 
624 	/*
625 	 * IMPORTANT: We have a problem. what do we do with symlinks?
626 	 * Modifying a hard link name makes sense, as we know the file it
627 	 * points at should have been seen already in the archive (and if it
628 	 * wasn't seen because of a read error or a bad archive, we lose
629 	 * anyway). But there are no such requirements for symlinks. On one
630 	 * hand the symlink that refers to a file in the archive will have to
631 	 * be modified to so it will still work at its new location in the
632 	 * file system. On the other hand a symlink that points elsewhere (and
633 	 * should continue to do so) should not be modified. There is clearly
634 	 * no perfect solution here. So we handle them like hardlinks. Clearly
635 	 * a replacement made by the interactive rename mapping is very likely
636 	 * to be correct since it applies to a single file and is an exact
637 	 * match. The regular expression replacements are a little harder to
638 	 * justify though. We claim that the symlink name is only likely
639 	 * to be replaced when it points within the file tree being moved and
640 	 * in that case it should be modified. what we really need to do is to
641 	 * call an oracle here. :)
642 	 */
643 	if (rephead != NULL) {
644 		/*
645 		 * we have replacement strings, modify the name and the link
646 		 * name if any.
647 		 */
648 		if ((res = rep_name(arcn->name, &(arcn->nlen), 1)) != 0)
649 			return(res);
650 
651 		if (((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
652 		    (arcn->type == PAX_HRG)) &&
653 		    ((res = rep_name(arcn->ln_name, &(arcn->ln_nlen), 0)) != 0))
654 			return(res);
655 	}
656 
657 	if (iflag) {
658 		/*
659 		 * perform interactive file rename, then map the link if any
660 		 */
661 		if ((res = tty_rename(arcn)) != 0)
662 			return(res);
663 		if ((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
664 		    (arcn->type == PAX_HRG))
665 			sub_name(arcn->ln_name, &(arcn->ln_nlen), sizeof(arcn->ln_name));
666 	}
667 	return(res);
668 }
669 
670 /*
671  * tty_rename()
672  *	Prompt the user for a replacement file name. A "." keeps the old name,
673  *	a empty line skips the file, and an EOF on reading the tty, will cause
674  *	pax to stop processing and exit. Otherwise the file name input, replaces
675  *	the old one.
676  * Return:
677  *	0 process this file, 1 skip this file, -1 we need to exit pax
678  */
679 
680 static int
681 tty_rename(ARCHD *arcn)
682 {
683 	char tmpname[PAXPATHLEN+2];
684 	int res;
685 
686 	/*
687 	 * prompt user for the replacement name for a file, keep trying until
688 	 * we get some reasonable input. Archives may have more than one file
689 	 * on them with the same name (from updates etc). We print verbose info
690 	 * on the file so the user knows what is up.
691 	 */
692 	tty_prnt("\nATTENTION: %s interactive file rename operation.\n", argv0);
693 
694 	for (;;) {
695 		ls_tty(arcn);
696 		tty_prnt("Input new name, or a \".\" to keep the old name, ");
697 		tty_prnt("or a \"return\" to skip this file.\n");
698 		tty_prnt("Input > ");
699 		if (tty_read(tmpname, sizeof(tmpname)) < 0)
700 			return(-1);
701 		if (strcmp(tmpname, "..") == 0) {
702 			tty_prnt("Try again, illegal file name: ..\n");
703 			continue;
704 		}
705 		if (strlen(tmpname) > PAXPATHLEN) {
706 			tty_prnt("Try again, file name too long\n");
707 			continue;
708 		}
709 		break;
710 	}
711 
712 	/*
713 	 * empty file name, skips this file. a "." leaves it alone
714 	 */
715 	if (tmpname[0] == '\0') {
716 		tty_prnt("Skipping file.\n");
717 		return(1);
718 	}
719 	if ((tmpname[0] == '.') && (tmpname[1] == '\0')) {
720 		tty_prnt("Processing continues, name unchanged.\n");
721 		return(0);
722 	}
723 
724 	/*
725 	 * ok the name changed. We may run into links that point at this
726 	 * file later. we have to remember where the user sent the file
727 	 * in order to repair any links.
728 	 */
729 	tty_prnt("Processing continues, name changed to: %s\n", tmpname);
730 	res = add_name(arcn->name, arcn->nlen, tmpname);
731 	arcn->nlen = l_strncpy(arcn->name, tmpname, sizeof(arcn->name) - 1);
732 	arcn->name[arcn->nlen] = '\0';
733 	if (res < 0)
734 		return(-1);
735 	return(0);
736 }
737 
738 /*
739  * set_dest()
740  *	fix up the file name and the link name (if any) so this file will land
741  *	in the destination directory (used during copy() -rw).
742  * Return:
743  *	0 if ok, -1 if failure (name too long)
744  */
745 
746 int
747 set_dest(ARCHD *arcn, char *dest_dir, int dir_len)
748 {
749 	if (fix_path(arcn->name, &(arcn->nlen), dest_dir, dir_len) < 0)
750 		return(-1);
751 
752 	/*
753 	 * It is really hard to deal with symlinks here, we cannot be sure
754 	 * if the name they point was moved (or will be moved). It is best to
755 	 * leave them alone.
756 	 */
757 	if ((arcn->type != PAX_HLK) && (arcn->type != PAX_HRG))
758 		return(0);
759 
760 	if (fix_path(arcn->ln_name, &(arcn->ln_nlen), dest_dir, dir_len) < 0)
761 		return(-1);
762 	return(0);
763 }
764 
765 /*
766  * fix_path
767  *	concatenate dir_name and or_name and store the result in or_name (if
768  *	it fits). This is one ugly function.
769  * Return:
770  *	0 if ok, -1 if the final name is too long
771  */
772 
773 static int
774 fix_path( char *or_name, int *or_len, char *dir_name, int dir_len)
775 {
776 	char *src;
777 	char *dest;
778 	char *start;
779 	int len;
780 
781 	/*
782 	 * we shift the or_name to the right enough to tack in the dir_name
783 	 * at the front. We make sure we have enough space for it all before
784 	 * we start. since dest always ends in a slash, we skip of or_name
785 	 * if it also starts with one.
786 	 */
787 	start = or_name;
788 	src = start + *or_len;
789 	dest = src + dir_len;
790 	if (*start == '/') {
791 		++start;
792 		--dest;
793 	}
794 	if ((len = dest - or_name) > PAXPATHLEN) {
795 		paxwarn(1, "File name %s/%s, too long", dir_name, start);
796 		return(-1);
797 	}
798 	*or_len = len;
799 
800 	/*
801 	 * enough space, shift
802 	 */
803 	while (src >= start)
804 		*dest-- = *src--;
805 	src = dir_name + dir_len - 1;
806 
807 	/*
808 	 * splice in the destination directory name
809 	 */
810 	while (src >= dir_name)
811 		*dest-- = *src--;
812 
813 	*(or_name + len) = '\0';
814 	return(0);
815 }
816 
817 /*
818  * rep_name()
819  *	walk down the list of replacement strings applying each one in order.
820  *	when we find one with a successful substitution, we modify the name
821  *	as specified. if required, we print the results. if the resulting name
822  *	is empty, we will skip this archive member. We use the regexp(3)
823  *	routines (regexp() ought to win a prize as having the most cryptic
824  *	library function manual page).
825  *	--Parameters--
826  *	name is the file name we are going to apply the regular expressions to
827  *	(and may be modified)
828  *	nlen is the length of this name (and is modified to hold the length of
829  *	the final string).
830  *	prnt is a flag that says whether to print the final result.
831  * Return:
832  *	0 if substitution was successful, 1 if we are to skip the file (the name
833  *	ended up empty)
834  */
835 
836 static int
837 rep_name(char *name, int *nlen, int prnt)
838 {
839 	REPLACE *pt;
840 	char *inpt;
841 	char *outpt;
842 	char *endpt;
843 	char *rpt;
844 	int found = 0;
845 	int res;
846 	regmatch_t pm[MAXSUBEXP];
847 	char nname[PAXPATHLEN+1];	/* final result of all replacements */
848 	char buf1[PAXPATHLEN+1];	/* where we work on the name */
849 
850 	/*
851 	 * copy the name into buf1, where we will work on it. We need to keep
852 	 * the orig string around so we can print out the result of the final
853 	 * replacement. We build up the final result in nname. inpt points at
854 	 * the string we apply the regular expression to. prnt is used to
855 	 * suppress printing when we handle replacements on the link field
856 	 * (the user already saw that substitution go by)
857 	 */
858 	pt = rephead;
859 	(void)strlcpy(buf1, name, sizeof(buf1));
860 	inpt = buf1;
861 	outpt = nname;
862 	endpt = outpt + PAXPATHLEN;
863 
864 	/*
865 	 * try each replacement string in order
866 	 */
867 	while (pt != NULL) {
868 		do {
869 			/*
870 			 * check for a successful substitution, if not go to
871 			 * the next pattern, or cleanup if we were global
872 			 */
873 			if (regexec(&(pt->rcmp), inpt, MAXSUBEXP, pm, 0) != 0)
874 				break;
875 
876 			/*
877 			 * ok we found one. We have three parts, the prefix
878 			 * which did not match, the section that did and the
879 			 * tail (that also did not match). Copy the prefix to
880 			 * the final output buffer (watching to make sure we
881 			 * do not create a string too long).
882 			 */
883 			found = 1;
884 			rpt = inpt + pm[0].rm_so;
885 
886 			while ((inpt < rpt) && (outpt < endpt))
887 				*outpt++ = *inpt++;
888 			if (outpt == endpt)
889 				break;
890 
891 			/*
892 			 * for the second part (which matched the regular
893 			 * expression) apply the substitution using the
894 			 * replacement string and place it the prefix in the
895 			 * final output. If we have problems, skip it.
896 			 */
897 			if ((res = resub(&(pt->rcmp),pm,inpt,pt->nstr,outpt,endpt))
898 			    < 0) {
899 				if (prnt)
900 					paxwarn(1, "Replacement name error %s",
901 					    name);
902 				return(1);
903 			}
904 			outpt += res;
905 
906 			/*
907 			 * we set up to look again starting at the first
908 			 * character in the tail (of the input string right
909 			 * after the last character matched by the regular
910 			 * expression (inpt always points at the first char in
911 			 * the string to process). If we are not doing a global
912 			 * substitution, we will use inpt to copy the tail to
913 			 * the final result. Make sure we do not overrun the
914 			 * output buffer
915 			 */
916 			inpt += pm[0].rm_eo - pm[0].rm_so;
917 
918 			if ((outpt == endpt) || (*inpt == '\0'))
919 				break;
920 
921 			/*
922 			 * if the user wants global we keep trying to
923 			 * substitute until it fails, then we are done.
924 			 */
925 		} while (pt->flgs & GLOB);
926 
927 		if (found)
928 			break;
929 
930 		/*
931 		 * a successful substitution did NOT occur, try the next one
932 		 */
933 		pt = pt->fow;
934 	}
935 
936 	if (found) {
937 		/*
938 		 * we had a substitution, copy the last tail piece (if there is
939 		 * room) to the final result
940 		 */
941 		while ((outpt < endpt) && (*inpt != '\0'))
942 			*outpt++ = *inpt++;
943 
944 		*outpt = '\0';
945 		if ((outpt == endpt) && (*inpt != '\0')) {
946 			if (prnt)
947 				paxwarn(1,"Replacement name too long %s >> %s",
948 				    name, nname);
949 			return(1);
950 		}
951 
952 		/*
953 		 * inform the user of the result if wanted
954 		 */
955 		if (prnt && (pt->flgs & PRNT)) {
956 			if (*nname == '\0')
957 				(void)fprintf(stderr,"%s >> <empty string>\n",
958 				    name);
959 			else
960 				(void)fprintf(stderr,"%s >> %s\n", name, nname);
961 		}
962 
963 		/*
964 		 * if empty inform the caller this file is to be skipped
965 		 * otherwise copy the new name over the orig name and return
966 		 */
967 		if (*nname == '\0')
968 			return(1);
969 		*nlen = l_strncpy(name, nname, PAXPATHLEN + 1);
970 		name[PAXPATHLEN] = '\0';
971 	}
972 	return(0);
973 }
974 
975 
976 /*
977  * resub()
978  *	apply the replacement to the matched expression. expand out the old
979  * 	style ed(1) subexpression expansion.
980  * Return:
981  *	-1 if error, or the number of characters added to the destination.
982  */
983 
984 static int
985 resub(regex_t *rp, regmatch_t *pm, char *orig, char *src, char *dest,
986 	char *destend)
987 {
988 	char *spt;
989 	char *dpt;
990 	char c;
991 	regmatch_t *pmpt;
992 	int len;
993 	int subexcnt;
994 
995 	spt =  src;
996 	dpt = dest;
997 	subexcnt = rp->re_nsub;
998 	while ((dpt < destend) && ((c = *spt++) != '\0')) {
999 		/*
1000 		 * see if we just have an ordinary replacement character
1001 		 * or we refer to a subexpression.
1002 		 */
1003 		if (c == '&') {
1004 			pmpt = pm;
1005 		} else if ((c == '\\') && (*spt >= '0') && (*spt <= '9')) {
1006 			/*
1007 			 * make sure there is a subexpression as specified
1008 			 */
1009 			if ((len = *spt++ - '0') > subexcnt)
1010 				return(-1);
1011 			pmpt = pm + len;
1012 		} else {
1013  			/*
1014 			 * Ordinary character, just copy it
1015 			 */
1016  			if ((c == '\\') && ((*spt == '\\') || (*spt == '&')))
1017  				c = *spt++;
1018  			*dpt++ = c;
1019 			continue;
1020 		}
1021 
1022 		/*
1023 		 * continue if the subexpression is bogus
1024 		 */
1025 		if ((pmpt->rm_so < 0) || (pmpt->rm_eo < 0) ||
1026 		    ((len = pmpt->rm_eo - pmpt->rm_so) <= 0))
1027 			continue;
1028 
1029 		/*
1030 		 * copy the subexpression to the destination.
1031 		 * fail if we run out of space or the match string is damaged
1032 		 */
1033 		if (len > (destend - dpt))
1034 			len = destend - dpt;
1035 		if (l_strncpy(dpt, orig + pmpt->rm_so, len) != len)
1036 			return(-1);
1037 		dpt += len;
1038 	}
1039 	return(dpt - dest);
1040 }
1041