xref: /freebsd/contrib/nvi/ex/ex_subst.c (revision a79b71281cd63ad7a6cc43a6d5673a2510b51630)
1 /*-
2  * Copyright (c) 1992, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "@(#)ex_subst.c	10.37 (Berkeley) 9/15/96";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #include <sys/time.h>
19 
20 #include <bitstring.h>
21 #include <ctype.h>
22 #include <errno.h>
23 #include <limits.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 
29 #include "../common/common.h"
30 #include "../vi/vi.h"
31 
32 #define	SUB_FIRST	0x01		/* The 'r' flag isn't reasonable. */
33 #define	SUB_MUSTSETR	0x02		/* The 'r' flag is required. */
34 
35 static int re_conv __P((SCR *, char **, size_t *, int *));
36 static int re_cscope_conv __P((SCR *, char **, size_t *, int *));
37 static int re_sub __P((SCR *,
38 		char *, char **, size_t *, size_t *, regmatch_t [10]));
39 static int re_tag_conv __P((SCR *, char **, size_t *, int *));
40 static int s __P((SCR *, EXCMD *, char *, regex_t *, u_int));
41 
42 /*
43  * ex_s --
44  *	[line [,line]] s[ubstitute] [[/;]pat[/;]/repl[/;] [cgr] [count] [#lp]]
45  *
46  *	Substitute on lines matching a pattern.
47  *
48  * PUBLIC: int ex_s __P((SCR *, EXCMD *));
49  */
50 int
51 ex_s(sp, cmdp)
52 	SCR *sp;
53 	EXCMD *cmdp;
54 {
55 	regex_t *re;
56 	size_t blen, len;
57 	u_int flags;
58 	int delim;
59 	char *bp, *ptrn, *rep, *p, *t;
60 
61 	/*
62 	 * Skip leading white space.
63 	 *
64 	 * !!!
65 	 * Historic vi allowed any non-alphanumeric to serve as the
66 	 * substitution command delimiter.
67 	 *
68 	 * !!!
69 	 * If the arguments are empty, it's the same as &, i.e. we
70 	 * repeat the last substitution.
71 	 */
72 	if (cmdp->argc == 0)
73 		goto subagain;
74 	for (p = cmdp->argv[0]->bp,
75 	    len = cmdp->argv[0]->len; len > 0; --len, ++p) {
76 		if (!isblank(*p))
77 			break;
78 	}
79 	if (len == 0)
80 subagain:	return (ex_subagain(sp, cmdp));
81 
82 	delim = *p++;
83 	if (isalnum(delim) || delim == '\\')
84 		return (s(sp, cmdp, p, &sp->subre_c, SUB_MUSTSETR));
85 
86 	/*
87 	 * !!!
88 	 * The full-blown substitute command reset the remembered
89 	 * state of the 'c' and 'g' suffices.
90 	 */
91 	sp->c_suffix = sp->g_suffix = 0;
92 
93 	/*
94 	 * Get the pattern string, toss escaping characters.
95 	 *
96 	 * !!!
97 	 * Historic vi accepted any of the following forms:
98 	 *
99 	 *	:s/abc/def/		change "abc" to "def"
100 	 *	:s/abc/def		change "abc" to "def"
101 	 *	:s/abc/			delete "abc"
102 	 *	:s/abc			delete "abc"
103 	 *
104 	 * QUOTING NOTE:
105 	 *
106 	 * Only toss an escaping character if it escapes a delimiter.
107 	 * This means that "s/A/\\\\f" replaces "A" with "\\f".  It
108 	 * would be nice to be more regular, i.e. for each layer of
109 	 * escaping a single escaping character is removed, but that's
110 	 * not how the historic vi worked.
111 	 */
112 	for (ptrn = t = p;;) {
113 		if (p[0] == '\0' || p[0] == delim) {
114 			if (p[0] == delim)
115 				++p;
116 			/*
117 			 * !!!
118 			 * Nul terminate the pattern string -- it's passed
119 			 * to regcomp which doesn't understand anything else.
120 			 */
121 			*t = '\0';
122 			break;
123 		}
124 		if (p[0] == '\\')
125 			if (p[1] == delim)
126 				++p;
127 			else if (p[1] == '\\')
128 				*t++ = *p++;
129 		*t++ = *p++;
130 	}
131 
132 	/*
133 	 * If the pattern string is empty, use the last RE (not just the
134 	 * last substitution RE).
135 	 */
136 	if (*ptrn == '\0') {
137 		if (sp->re == NULL) {
138 			ex_emsg(sp, NULL, EXM_NOPREVRE);
139 			return (1);
140 		}
141 
142 		/* Re-compile the RE if necessary. */
143 		if (!F_ISSET(sp, SC_RE_SEARCH) && re_compile(sp,
144 		    sp->re, sp->re_len, NULL, NULL, &sp->re_c, RE_C_SEARCH))
145 			return (1);
146 		flags = 0;
147 	} else {
148 		/*
149 		 * !!!
150 		 * Compile the RE.  Historic practice is that substitutes set
151 		 * the search direction as well as both substitute and search
152 		 * RE's.  We compile the RE twice, as we don't want to bother
153 		 * ref counting the pattern string and (opaque) structure.
154 		 */
155 		if (re_compile(sp, ptrn, t - ptrn,
156 		    &sp->re, &sp->re_len, &sp->re_c, RE_C_SEARCH))
157 			return (1);
158 		if (re_compile(sp, ptrn, t - ptrn,
159 		    &sp->subre, &sp->subre_len, &sp->subre_c, RE_C_SUBST))
160 			return (1);
161 
162 		flags = SUB_FIRST;
163 		sp->searchdir = FORWARD;
164 	}
165 	re = &sp->re_c;
166 
167 	/*
168 	 * Get the replacement string.
169 	 *
170 	 * The special character & (\& if O_MAGIC not set) matches the
171 	 * entire RE.  No handling of & is required here, it's done by
172 	 * re_sub().
173 	 *
174 	 * The special character ~ (\~ if O_MAGIC not set) inserts the
175 	 * previous replacement string into this replacement string.
176 	 * Count ~'s to figure out how much space we need.  We could
177 	 * special case nonexistent last patterns or whether or not
178 	 * O_MAGIC is set, but it's probably not worth the effort.
179 	 *
180 	 * QUOTING NOTE:
181 	 *
182 	 * Only toss an escaping character if it escapes a delimiter or
183 	 * if O_MAGIC is set and it escapes a tilde.
184 	 *
185 	 * !!!
186 	 * If the entire replacement pattern is "%", then use the last
187 	 * replacement pattern.  This semantic was added to vi in System
188 	 * V and then percolated elsewhere, presumably around the time
189 	 * that it was added to their version of ed(1).
190 	 */
191 	if (p[0] == '\0' || p[0] == delim) {
192 		if (p[0] == delim)
193 			++p;
194 		if (sp->repl != NULL)
195 			free(sp->repl);
196 		sp->repl = NULL;
197 		sp->repl_len = 0;
198 	} else if (p[0] == '%' && (p[1] == '\0' || p[1] == delim))
199 		p += p[1] == delim ? 2 : 1;
200 	else {
201 		for (rep = p, len = 0;
202 		    p[0] != '\0' && p[0] != delim; ++p, ++len)
203 			if (p[0] == '~')
204 				len += sp->repl_len;
205 		GET_SPACE_RET(sp, bp, blen, len);
206 		for (t = bp, len = 0, p = rep;;) {
207 			if (p[0] == '\0' || p[0] == delim) {
208 				if (p[0] == delim)
209 					++p;
210 				break;
211 			}
212 			if (p[0] == '\\') {
213 				if (p[1] == delim)
214 					++p;
215 				else if (p[1] == '\\') {
216 					*t++ = *p++;
217 					++len;
218 				} else if (p[1] == '~') {
219 					++p;
220 					if (!O_ISSET(sp, O_MAGIC))
221 						goto tilde;
222 				}
223 			} else if (p[0] == '~' && O_ISSET(sp, O_MAGIC)) {
224 tilde:				++p;
225 				memcpy(t, sp->repl, sp->repl_len);
226 				t += sp->repl_len;
227 				len += sp->repl_len;
228 				continue;
229 			}
230 			*t++ = *p++;
231 			++len;
232 		}
233 		if ((sp->repl_len = len) != 0) {
234 			if (sp->repl != NULL)
235 				free(sp->repl);
236 			if ((sp->repl = malloc(len)) == NULL) {
237 				msgq(sp, M_SYSERR, NULL);
238 				FREE_SPACE(sp, bp, blen);
239 				return (1);
240 			}
241 			memcpy(sp->repl, bp, len);
242 		}
243 		FREE_SPACE(sp, bp, blen);
244 	}
245 	return (s(sp, cmdp, p, re, flags));
246 }
247 
248 /*
249  * ex_subagain --
250  *	[line [,line]] & [cgr] [count] [#lp]]
251  *
252  *	Substitute using the last substitute RE and replacement pattern.
253  *
254  * PUBLIC: int ex_subagain __P((SCR *, EXCMD *));
255  */
256 int
257 ex_subagain(sp, cmdp)
258 	SCR *sp;
259 	EXCMD *cmdp;
260 {
261 	if (sp->subre == NULL) {
262 		ex_emsg(sp, NULL, EXM_NOPREVRE);
263 		return (1);
264 	}
265 	if (!F_ISSET(sp, SC_RE_SUBST) && re_compile(sp,
266 	    sp->subre, sp->subre_len, NULL, NULL, &sp->subre_c, RE_C_SUBST))
267 		return (1);
268 	return (s(sp,
269 	    cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->subre_c, 0));
270 }
271 
272 /*
273  * ex_subtilde --
274  *	[line [,line]] ~ [cgr] [count] [#lp]]
275  *
276  *	Substitute using the last RE and last substitute replacement pattern.
277  *
278  * PUBLIC: int ex_subtilde __P((SCR *, EXCMD *));
279  */
280 int
281 ex_subtilde(sp, cmdp)
282 	SCR *sp;
283 	EXCMD *cmdp;
284 {
285 	if (sp->re == NULL) {
286 		ex_emsg(sp, NULL, EXM_NOPREVRE);
287 		return (1);
288 	}
289 	if (!F_ISSET(sp, SC_RE_SEARCH) && re_compile(sp,
290 	    sp->re, sp->re_len, NULL, NULL, &sp->re_c, RE_C_SEARCH))
291 		return (1);
292 	return (s(sp,
293 	    cmdp, cmdp->argc ? cmdp->argv[0]->bp : NULL, &sp->re_c, 0));
294 }
295 
296 /*
297  * s --
298  * Do the substitution.  This stuff is *really* tricky.  There are lots of
299  * special cases, and general nastiness.  Don't mess with it unless you're
300  * pretty confident.
301  *
302  * The nasty part of the substitution is what happens when the replacement
303  * string contains newlines.  It's a bit tricky -- consider the information
304  * that has to be retained for "s/f\(o\)o/^M\1^M\1/".  The solution here is
305  * to build a set of newline offsets which we use to break the line up later,
306  * when the replacement is done.  Don't change it unless you're *damned*
307  * confident.
308  */
309 #define	NEEDNEWLINE(sp) {						\
310 	if (sp->newl_len == sp->newl_cnt) {				\
311 		sp->newl_len += 25;					\
312 		REALLOC(sp, sp->newl, size_t *,				\
313 		    sp->newl_len * sizeof(size_t));			\
314 		if (sp->newl == NULL) {					\
315 			sp->newl_len = 0;				\
316 			return (1);					\
317 		}							\
318 	}								\
319 }
320 
321 #define	BUILD(sp, l, len) {						\
322 	if (lbclen + (len) > lblen) {					\
323 		lblen += MAX(lbclen + (len), 256);			\
324 		REALLOC(sp, lb, char *, lblen);				\
325 		if (lb == NULL) {					\
326 			lbclen = 0;					\
327 			return (1);					\
328 		}							\
329 	}								\
330 	memcpy(lb + lbclen, l, len);					\
331 	lbclen += len;							\
332 }
333 
334 #define	NEEDSP(sp, len, pnt) {						\
335 	if (lbclen + (len) > lblen) {					\
336 		lblen += MAX(lbclen + (len), 256);			\
337 		REALLOC(sp, lb, char *, lblen);				\
338 		if (lb == NULL) {					\
339 			lbclen = 0;					\
340 			return (1);					\
341 		}							\
342 		pnt = lb + lbclen;					\
343 	}								\
344 }
345 
346 static int
347 s(sp, cmdp, s, re, flags)
348 	SCR *sp;
349 	EXCMD *cmdp;
350 	char *s;
351 	regex_t *re;
352 	u_int flags;
353 {
354 	EVENT ev;
355 	MARK from, to;
356 	TEXTH tiq;
357 	recno_t elno, lno, slno;
358 	regmatch_t match[10];
359 	size_t blen, cnt, last, lbclen, lblen, len, llen;
360 	size_t offset, saved_offset, scno;
361 	int cflag, lflag, nflag, pflag, rflag;
362 	int didsub, do_eol_match, eflags, empty_ok, eval;
363 	int linechanged, matched, quit, rval;
364 	char *bp, *lb;
365 
366 	NEEDFILE(sp, cmdp);
367 
368 	slno = sp->lno;
369 	scno = sp->cno;
370 
371 	/*
372 	 * !!!
373 	 * Historically, the 'g' and 'c' suffices were always toggled as flags,
374 	 * so ":s/A/B/" was the same as ":s/A/B/ccgg".  If O_EDCOMPATIBLE was
375 	 * not set, they were initialized to 0 for all substitute commands.  If
376 	 * O_EDCOMPATIBLE was set, they were initialized to 0 only if the user
377 	 * specified substitute/replacement patterns (see ex_s()).
378 	 */
379 	if (!O_ISSET(sp, O_EDCOMPATIBLE))
380 		sp->c_suffix = sp->g_suffix = 0;
381 
382 	/*
383 	 * Historic vi permitted the '#', 'l' and 'p' options in vi mode, but
384 	 * it only displayed the last change.  I'd disallow them, but they are
385 	 * useful in combination with the [v]global commands.  In the current
386 	 * model the problem is combining them with the 'c' flag -- the screen
387 	 * would have to flip back and forth between the confirm screen and the
388 	 * ex print screen, which would be pretty awful.  We do display all
389 	 * changes, though, for what that's worth.
390 	 *
391 	 * !!!
392 	 * Historic vi was fairly strict about the order of "options", the
393 	 * count, and "flags".  I'm somewhat fuzzy on the difference between
394 	 * options and flags, anyway, so this is a simpler approach, and we
395 	 * just take it them in whatever order the user gives them.  (The ex
396 	 * usage statement doesn't reflect this.)
397 	 */
398 	cflag = lflag = nflag = pflag = rflag = 0;
399 	if (s == NULL)
400 		goto noargs;
401 	for (lno = OOBLNO; *s != '\0'; ++s)
402 		switch (*s) {
403 		case ' ':
404 		case '\t':
405 			continue;
406 		case '+':
407 			++cmdp->flagoff;
408 			break;
409 		case '-':
410 			--cmdp->flagoff;
411 			break;
412 		case '0': case '1': case '2': case '3': case '4':
413 		case '5': case '6': case '7': case '8': case '9':
414 			if (lno != OOBLNO)
415 				goto usage;
416 			errno = 0;
417 			lno = strtoul(s, &s, 10);
418 			if (*s == '\0')		/* Loop increment correction. */
419 				--s;
420 			if (errno == ERANGE) {
421 				if (lno == LONG_MAX)
422 					msgq(sp, M_ERR, "153|Count overflow");
423 				else if (lno == LONG_MIN)
424 					msgq(sp, M_ERR, "154|Count underflow");
425 				else
426 					msgq(sp, M_SYSERR, NULL);
427 				return (1);
428 			}
429 			/*
430 			 * In historic vi, the count was inclusive from the
431 			 * second address.
432 			 */
433 			cmdp->addr1.lno = cmdp->addr2.lno;
434 			cmdp->addr2.lno += lno - 1;
435 			if (!db_exist(sp, cmdp->addr2.lno) &&
436 			    db_last(sp, &cmdp->addr2.lno))
437 				return (1);
438 			break;
439 		case '#':
440 			nflag = 1;
441 			break;
442 		case 'c':
443 			sp->c_suffix = !sp->c_suffix;
444 
445 			/* Ex text structure initialization. */
446 			if (F_ISSET(sp, SC_EX)) {
447 				memset(&tiq, 0, sizeof(TEXTH));
448 				CIRCLEQ_INIT(&tiq);
449 			}
450 			break;
451 		case 'g':
452 			sp->g_suffix = !sp->g_suffix;
453 			break;
454 		case 'l':
455 			lflag = 1;
456 			break;
457 		case 'p':
458 			pflag = 1;
459 			break;
460 		case 'r':
461 			if (LF_ISSET(SUB_FIRST)) {
462 				msgq(sp, M_ERR,
463 		    "155|Regular expression specified; r flag meaningless");
464 				return (1);
465 			}
466 			if (!F_ISSET(sp, SC_RE_SEARCH)) {
467 				ex_emsg(sp, NULL, EXM_NOPREVRE);
468 				return (1);
469 			}
470 			rflag = 1;
471 			re = &sp->re_c;
472 			break;
473 		default:
474 			goto usage;
475 		}
476 
477 	if (*s != '\0' || !rflag && LF_ISSET(SUB_MUSTSETR)) {
478 usage:		ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
479 		return (1);
480 	}
481 
482 noargs:	if (F_ISSET(sp, SC_VI) && sp->c_suffix && (lflag || nflag || pflag)) {
483 		msgq(sp, M_ERR,
484 "156|The #, l and p flags may not be combined with the c flag in vi mode");
485 		return (1);
486 	}
487 
488 	/*
489 	 * bp:		if interactive, line cache
490 	 * blen:	if interactive, line cache length
491 	 * lb:		build buffer pointer.
492 	 * lbclen:	current length of built buffer.
493 	 * lblen;	length of build buffer.
494 	 */
495 	bp = lb = NULL;
496 	blen = lbclen = lblen = 0;
497 
498 	/* For each line... */
499 	for (matched = quit = 0, lno = cmdp->addr1.lno,
500 	    elno = cmdp->addr2.lno; !quit && lno <= elno; ++lno) {
501 
502 		/* Someone's unhappy, time to stop. */
503 		if (INTERRUPTED(sp))
504 			break;
505 
506 		/* Get the line. */
507 		if (db_get(sp, lno, DBG_FATAL, &s, &llen))
508 			goto err;
509 
510 		/*
511 		 * Make a local copy if doing confirmation -- when calling
512 		 * the confirm routine we're likely to lose the cached copy.
513 		 */
514 		if (sp->c_suffix) {
515 			if (bp == NULL) {
516 				GET_SPACE_RET(sp, bp, blen, llen);
517 			} else
518 				ADD_SPACE_RET(sp, bp, blen, llen);
519 			memcpy(bp, s, llen);
520 			s = bp;
521 		}
522 
523 		/* Start searching from the beginning. */
524 		offset = 0;
525 		len = llen;
526 
527 		/* Reset the build buffer offset. */
528 		lbclen = 0;
529 
530 		/* Reset empty match flag. */
531 		empty_ok = 1;
532 
533 		/*
534 		 * We don't want to have to do a setline if the line didn't
535 		 * change -- keep track of whether or not this line changed.
536 		 * If doing confirmations, don't want to keep setting the
537 		 * line if change is refused -- keep track of substitutions.
538 		 */
539 		didsub = linechanged = 0;
540 
541 		/* New line, do an EOL match. */
542 		do_eol_match = 1;
543 
544 		/* It's not nul terminated, but we pretend it is. */
545 		eflags = REG_STARTEND;
546 
547 		/*
548 		 * The search area is from s + offset to the EOL.
549 		 *
550 		 * Generally, match[0].rm_so is the offset of the start
551 		 * of the match from the start of the search, and offset
552 		 * is the offset of the start of the last search.
553 		 */
554 nextmatch:	match[0].rm_so = 0;
555 		match[0].rm_eo = len;
556 
557 		/* Get the next match. */
558 		eval = regexec(re, (char *)s + offset, 10, match, eflags);
559 
560 		/*
561 		 * There wasn't a match or if there was an error, deal with
562 		 * it.  If there was a previous match in this line, resolve
563 		 * the changes into the database.  Otherwise, just move on.
564 		 */
565 		if (eval == REG_NOMATCH)
566 			goto endmatch;
567 		if (eval != 0) {
568 			re_error(sp, eval, re);
569 			goto err;
570 		}
571 		matched = 1;
572 
573 		/* Only the first search can match an anchored expression. */
574 		eflags |= REG_NOTBOL;
575 
576 		/*
577 		 * !!!
578 		 * It's possible to match 0-length strings -- for example, the
579 		 * command s;a*;X;, when matched against the string "aabb" will
580 		 * result in "XbXbX", i.e. the matches are "aa", the space
581 		 * between the b's and the space between the b's and the end of
582 		 * the string.  There is a similar space between the beginning
583 		 * of the string and the a's.  The rule that we use (because vi
584 		 * historically used it) is that any 0-length match, occurring
585 		 * immediately after a match, is ignored.  Otherwise, the above
586 		 * example would have resulted in "XXbXbX".  Another example is
587 		 * incorrectly using " *" to replace groups of spaces with one
588 		 * space.
589 		 *
590 		 * The way we do this is that if we just had a successful match,
591 		 * the starting offset does not skip characters, and the match
592 		 * is empty, ignore the match and move forward.  If there's no
593 		 * more characters in the string, we were attempting to match
594 		 * after the last character, so quit.
595 		 */
596 		if (!empty_ok && match[0].rm_so == 0 && match[0].rm_eo == 0) {
597 			empty_ok = 1;
598 			if (len == 0)
599 				goto endmatch;
600 			BUILD(sp, s + offset, 1)
601 			++offset;
602 			--len;
603 			goto nextmatch;
604 		}
605 
606 		/* Confirm change. */
607 		if (sp->c_suffix) {
608 			/*
609 			 * Set the cursor position for confirmation.  Note,
610 			 * if we matched on a '$', the cursor may be past
611 			 * the end of line.
612 			 */
613 			from.lno = to.lno = lno;
614 			from.cno = match[0].rm_so + offset;
615 			to.cno = match[0].rm_eo + offset;
616 			/*
617 			 * Both ex and vi have to correct for a change before
618 			 * the first character in the line.
619 			 */
620 			if (llen == 0)
621 				from.cno = to.cno = 0;
622 			if (F_ISSET(sp, SC_VI)) {
623 				/*
624 				 * Only vi has to correct for a change after
625 				 * the last character in the line.
626 				 *
627 				 * XXX
628 				 * It would be nice to change the vi code so
629 				 * that we could display a cursor past EOL.
630 				 */
631 				if (to.cno >= llen)
632 					to.cno = llen - 1;
633 				if (from.cno >= llen)
634 					from.cno = llen - 1;
635 
636 				sp->lno = from.lno;
637 				sp->cno = from.cno;
638 				if (vs_refresh(sp, 1))
639 					goto err;
640 
641 				vs_update(sp, msg_cat(sp,
642 				    "169|Confirm change? [n]", NULL), NULL);
643 
644 				if (v_event_get(sp, &ev, 0, 0))
645 					goto err;
646 				switch (ev.e_event) {
647 				case E_CHARACTER:
648 					break;
649 				case E_EOF:
650 				case E_ERR:
651 				case E_INTERRUPT:
652 					goto lquit;
653 				default:
654 					v_event_err(sp, &ev);
655 					goto lquit;
656 				}
657 			} else {
658 				if (ex_print(sp, cmdp, &from, &to, 0) ||
659 				    ex_scprint(sp, &from, &to))
660 					goto lquit;
661 				if (ex_txt(sp, &tiq, 0, TXT_CR))
662 					goto err;
663 				ev.e_c = tiq.cqh_first->lb[0];
664 			}
665 
666 			switch (ev.e_c) {
667 			case CH_YES:
668 				break;
669 			default:
670 			case CH_NO:
671 				didsub = 0;
672 				BUILD(sp, s +offset, match[0].rm_eo);
673 				goto skip;
674 			case CH_QUIT:
675 				/* Set the quit/interrupted flags. */
676 lquit:				quit = 1;
677 				F_SET(sp->gp, G_INTERRUPTED);
678 
679 				/*
680 				 * Resolve any changes, then return to (and
681 				 * exit from) the main loop.
682 				 */
683 				goto endmatch;
684 			}
685 		}
686 
687 		/*
688 		 * Set the cursor to the last position changed, converting
689 		 * from 1-based to 0-based.
690 		 */
691 		sp->lno = lno;
692 		sp->cno = match[0].rm_so;
693 
694 		/* Copy the bytes before the match into the build buffer. */
695 		BUILD(sp, s + offset, match[0].rm_so);
696 
697 		/* Substitute the matching bytes. */
698 		didsub = 1;
699 		if (re_sub(sp, s + offset, &lb, &lbclen, &lblen, match))
700 			goto err;
701 
702 		/* Set the change flag so we know this line was modified. */
703 		linechanged = 1;
704 
705 		/* Move past the matched bytes. */
706 skip:		offset += match[0].rm_eo;
707 		len -= match[0].rm_eo;
708 
709 		/* A match cannot be followed by an empty pattern. */
710 		empty_ok = 0;
711 
712 		/*
713 		 * If doing a global change with confirmation, we have to
714 		 * update the screen.  The basic idea is to store the line
715 		 * so the screen update routines can find it, and restart.
716 		 */
717 		if (didsub && sp->c_suffix && sp->g_suffix) {
718 			/*
719 			 * The new search offset will be the end of the
720 			 * modified line.
721 			 */
722 			saved_offset = lbclen;
723 
724 			/* Copy the rest of the line. */
725 			if (len)
726 				BUILD(sp, s + offset, len)
727 
728 			/* Set the new offset. */
729 			offset = saved_offset;
730 
731 			/* Store inserted lines, adjusting the build buffer. */
732 			last = 0;
733 			if (sp->newl_cnt) {
734 				for (cnt = 0;
735 				    cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
736 					if (db_insert(sp, lno,
737 					    lb + last, sp->newl[cnt] - last))
738 						goto err;
739 					last = sp->newl[cnt] + 1;
740 					++sp->rptlines[L_ADDED];
741 				}
742 				lbclen -= last;
743 				offset -= last;
744 				sp->newl_cnt = 0;
745 			}
746 
747 			/* Store and retrieve the line. */
748 			if (db_set(sp, lno, lb + last, lbclen))
749 				goto err;
750 			if (db_get(sp, lno, DBG_FATAL, &s, &llen))
751 				goto err;
752 			ADD_SPACE_RET(sp, bp, blen, llen)
753 			memcpy(bp, s, llen);
754 			s = bp;
755 			len = llen - offset;
756 
757 			/* Restart the build. */
758 			lbclen = 0;
759 			BUILD(sp, s, offset);
760 
761 			/*
762 			 * If we haven't already done the after-the-string
763 			 * match, do one.  Set REG_NOTEOL so the '$' pattern
764 			 * only matches once.
765 			 */
766 			if (!do_eol_match)
767 				goto endmatch;
768 			if (offset == len) {
769 				do_eol_match = 0;
770 				eflags |= REG_NOTEOL;
771 			}
772 			goto nextmatch;
773 		}
774 
775 		/*
776 		 * If it's a global:
777 		 *
778 		 * If at the end of the string, do a test for the after
779 		 * the string match.  Set REG_NOTEOL so the '$' pattern
780 		 * only matches once.
781 		 */
782 		if (sp->g_suffix && do_eol_match) {
783 			if (len == 0) {
784 				do_eol_match = 0;
785 				eflags |= REG_NOTEOL;
786 			}
787 			goto nextmatch;
788 		}
789 
790 endmatch:	if (!linechanged)
791 			continue;
792 
793 		/* Copy any remaining bytes into the build buffer. */
794 		if (len)
795 			BUILD(sp, s + offset, len)
796 
797 		/* Store inserted lines, adjusting the build buffer. */
798 		last = 0;
799 		if (sp->newl_cnt) {
800 			for (cnt = 0;
801 			    cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
802 				if (db_insert(sp,
803 				    lno, lb + last, sp->newl[cnt] - last))
804 					goto err;
805 				last = sp->newl[cnt] + 1;
806 				++sp->rptlines[L_ADDED];
807 			}
808 			lbclen -= last;
809 			sp->newl_cnt = 0;
810 		}
811 
812 		/* Store the changed line. */
813 		if (db_set(sp, lno, lb + last, lbclen))
814 			goto err;
815 
816 		/* Update changed line counter. */
817 		if (sp->rptlchange != lno) {
818 			sp->rptlchange = lno;
819 			++sp->rptlines[L_CHANGED];
820 		}
821 
822 		/*
823 		 * !!!
824 		 * Display as necessary.  Historic practice is to only
825 		 * display the last line of a line split into multiple
826 		 * lines.
827 		 */
828 		if (lflag || nflag || pflag) {
829 			from.lno = to.lno = lno;
830 			from.cno = to.cno = 0;
831 			if (lflag)
832 				(void)ex_print(sp, cmdp, &from, &to, E_C_LIST);
833 			if (nflag)
834 				(void)ex_print(sp, cmdp, &from, &to, E_C_HASH);
835 			if (pflag)
836 				(void)ex_print(sp, cmdp, &from, &to, E_C_PRINT);
837 		}
838 	}
839 
840 	/*
841 	 * !!!
842 	 * Historically, vi attempted to leave the cursor at the same place if
843 	 * the substitution was done at the current cursor position.  Otherwise
844 	 * it moved it to the first non-blank of the last line changed.  There
845 	 * were some problems: for example, :s/$/foo/ with the cursor on the
846 	 * last character of the line left the cursor on the last character, or
847 	 * the & command with multiple occurrences of the matching string in the
848 	 * line usually left the cursor in a fairly random position.
849 	 *
850 	 * We try to do the same thing, with the exception that if the user is
851 	 * doing substitution with confirmation, we move to the last line about
852 	 * which the user was consulted, as opposed to the last line that they
853 	 * actually changed.  This prevents a screen flash if the user doesn't
854 	 * change many of the possible lines.
855 	 */
856 	if (!sp->c_suffix && (sp->lno != slno || sp->cno != scno)) {
857 		sp->cno = 0;
858 		(void)nonblank(sp, sp->lno, &sp->cno);
859 	}
860 
861 	/*
862 	 * If not in a global command, and nothing matched, say so.
863 	 * Else, if none of the lines displayed, put something up.
864 	 */
865 	rval = 0;
866 	if (!matched) {
867 		if (!F_ISSET(sp, SC_EX_GLOBAL)) {
868 			msgq(sp, M_ERR, "157|No match found");
869 			goto err;
870 		}
871 	} else if (!lflag && !nflag && !pflag)
872 		F_SET(cmdp, E_AUTOPRINT);
873 
874 	if (0) {
875 err:		rval = 1;
876 	}
877 
878 	if (bp != NULL)
879 		FREE_SPACE(sp, bp, blen);
880 	if (lb != NULL)
881 		free(lb);
882 	return (rval);
883 }
884 
885 /*
886  * re_compile --
887  *	Compile the RE.
888  *
889  * PUBLIC: int re_compile __P((SCR *,
890  * PUBLIC:     char *, size_t, char **, size_t *, regex_t *, u_int));
891  */
892 int
893 re_compile(sp, ptrn, plen, ptrnp, lenp, rep, flags)
894 	SCR *sp;
895 	char *ptrn, **ptrnp;
896 	size_t plen, *lenp;
897 	regex_t *rep;
898 	u_int flags;
899 {
900 	size_t len;
901 	int reflags, replaced, rval;
902 	char *p;
903 
904 	/* Set RE flags. */
905 	reflags = 0;
906 	if (!LF_ISSET(RE_C_CSCOPE | RE_C_TAG)) {
907 		if (O_ISSET(sp, O_EXTENDED))
908 			reflags |= REG_EXTENDED;
909 		if (O_ISSET(sp, O_IGNORECASE))
910 			reflags |= REG_ICASE;
911 		if (O_ISSET(sp, O_ICLOWER)) {
912 			for (p = ptrn, len = plen; len > 0; ++p, --len)
913 				if (isupper(*p))
914 					break;
915 			if (len == 0)
916 				reflags |= REG_ICASE;
917 		}
918 	}
919 
920 	/* If we're replacing a saved value, clear the old one. */
921 	if (LF_ISSET(RE_C_SEARCH) && F_ISSET(sp, SC_RE_SEARCH)) {
922 		regfree(&sp->re_c);
923 		F_CLR(sp, SC_RE_SEARCH);
924 	}
925 	if (LF_ISSET(RE_C_SUBST) && F_ISSET(sp, SC_RE_SUBST)) {
926 		regfree(&sp->subre_c);
927 		F_CLR(sp, SC_RE_SUBST);
928 	}
929 
930 	/*
931 	 * If we're saving the string, it's a pattern we haven't seen before,
932 	 * so convert the vi-style RE's to POSIX 1003.2 RE's.  Save a copy for
933 	 * later recompilation.   Free any previously saved value.
934 	 */
935 	if (ptrnp != NULL) {
936 		if (LF_ISSET(RE_C_CSCOPE)) {
937 			if (re_cscope_conv(sp, &ptrn, &plen, &replaced))
938 				return (1);
939 			/*
940 			 * XXX
941 			 * Currently, the match-any-<blank> expression used in
942 			 * re_cscope_conv() requires extended RE's.  This may
943 			 * not be right or safe.
944 			 */
945 			reflags |= REG_EXTENDED;
946 		} else if (LF_ISSET(RE_C_TAG)) {
947 			if (re_tag_conv(sp, &ptrn, &plen, &replaced))
948 				return (1);
949 		} else
950 			if (re_conv(sp, &ptrn, &plen, &replaced))
951 				return (1);
952 
953 		/* Discard previous pattern. */
954 		if (*ptrnp != NULL) {
955 			free(*ptrnp);
956 			*ptrnp = NULL;
957 		}
958 		if (lenp != NULL)
959 			*lenp = plen;
960 
961 		/*
962 		 * Copy the string into allocated memory.
963 		 *
964 		 * XXX
965 		 * Regcomp isn't 8-bit clean, so the pattern is nul-terminated
966 		 * for now.  There's just no other solution.
967 		 */
968 		MALLOC(sp, *ptrnp, char *, plen + 1);
969 		if (*ptrnp != NULL) {
970 			memcpy(*ptrnp, ptrn, plen);
971 			(*ptrnp)[plen] = '\0';
972 		}
973 
974 		/* Free up conversion-routine-allocated memory. */
975 		if (replaced)
976 			FREE_SPACE(sp, ptrn, 0);
977 
978 		if (*ptrnp == NULL)
979 			return (1);
980 
981 		ptrn = *ptrnp;
982 	}
983 
984 	/*
985 	 * XXX
986 	 * Regcomp isn't 8-bit clean, so we just lost if the pattern
987 	 * contained a nul.  Bummer!
988 	 */
989 	if ((rval = regcomp(rep, ptrn, /* plen, */ reflags)) != 0) {
990 		if (!LF_ISSET(RE_C_SILENT))
991 			re_error(sp, rval, rep);
992 		return (1);
993 	}
994 
995 	if (LF_ISSET(RE_C_SEARCH))
996 		F_SET(sp, SC_RE_SEARCH);
997 	if (LF_ISSET(RE_C_SUBST))
998 		F_SET(sp, SC_RE_SUBST);
999 
1000 	return (0);
1001 }
1002 
1003 /*
1004  * re_conv --
1005  *	Convert vi's regular expressions into something that the
1006  *	the POSIX 1003.2 RE functions can handle.
1007  *
1008  * There are three conversions we make to make vi's RE's (specifically
1009  * the global, search, and substitute patterns) work with POSIX RE's.
1010  *
1011  * 1: If O_MAGIC is not set, strip backslashes from the magic character
1012  *    set (.[*~) that have them, and add them to the ones that don't.
1013  * 2: If O_MAGIC is not set, the string "\~" is replaced with the text
1014  *    from the last substitute command's replacement string.  If O_MAGIC
1015  *    is set, it's the string "~".
1016  * 3: The pattern \<ptrn\> does "word" searches, convert it to use the
1017  *    new RE escapes.
1018  *
1019  * !!!/XXX
1020  * This doesn't exactly match the historic behavior of vi because we do
1021  * the ~ substitution before calling the RE engine, so magic characters
1022  * in the replacement string will be expanded by the RE engine, and they
1023  * weren't historically.  It's a bug.
1024  */
1025 static int
1026 re_conv(sp, ptrnp, plenp, replacedp)
1027 	SCR *sp;
1028 	char **ptrnp;
1029 	size_t *plenp;
1030 	int *replacedp;
1031 {
1032 	size_t blen, len, needlen;
1033 	int magic;
1034 	char *bp, *p, *t;
1035 
1036 	/*
1037 	 * First pass through, we figure out how much space we'll need.
1038 	 * We do it in two passes, on the grounds that most of the time
1039 	 * the user is doing a search and won't have magic characters.
1040 	 * That way we can skip most of the memory allocation and copies.
1041 	 */
1042 	magic = 0;
1043 	for (p = *ptrnp, len = *plenp, needlen = 0; len > 0; ++p, --len)
1044 		switch (*p) {
1045 		case '\\':
1046 			if (len > 1) {
1047 				--len;
1048 				switch (*++p) {
1049 				case '<':
1050 					magic = 1;
1051 					needlen += sizeof(RE_WSTART);
1052 					break;
1053 				case '>':
1054 					magic = 1;
1055 					needlen += sizeof(RE_WSTOP);
1056 					break;
1057 				case '~':
1058 					if (!O_ISSET(sp, O_MAGIC)) {
1059 						magic = 1;
1060 						needlen += sp->repl_len;
1061 					}
1062 					break;
1063 				case '.':
1064 				case '[':
1065 				case '*':
1066 					if (!O_ISSET(sp, O_MAGIC)) {
1067 						magic = 1;
1068 						needlen += 1;
1069 					}
1070 					break;
1071 				default:
1072 					needlen += 2;
1073 				}
1074 			} else
1075 				needlen += 1;
1076 			break;
1077 		case '~':
1078 			if (O_ISSET(sp, O_MAGIC)) {
1079 				magic = 1;
1080 				needlen += sp->repl_len;
1081 			}
1082 			break;
1083 		case '.':
1084 		case '[':
1085 		case '*':
1086 			if (!O_ISSET(sp, O_MAGIC)) {
1087 				magic = 1;
1088 				needlen += 2;
1089 			}
1090 			break;
1091 		default:
1092 			needlen += 1;
1093 			break;
1094 		}
1095 
1096 	if (!magic) {
1097 		*replacedp = 0;
1098 		return (0);
1099 	}
1100 
1101 	/* Get enough memory to hold the final pattern. */
1102 	*replacedp = 1;
1103 	GET_SPACE_RET(sp, bp, blen, needlen);
1104 
1105 	for (p = *ptrnp, len = *plenp, t = bp; len > 0; ++p, --len)
1106 		switch (*p) {
1107 		case '\\':
1108 			if (len > 1) {
1109 				--len;
1110 				switch (*++p) {
1111 				case '<':
1112 					memcpy(t,
1113 					    RE_WSTART, sizeof(RE_WSTART) - 1);
1114 					t += sizeof(RE_WSTART) - 1;
1115 					break;
1116 				case '>':
1117 					memcpy(t,
1118 					    RE_WSTOP, sizeof(RE_WSTOP) - 1);
1119 					t += sizeof(RE_WSTOP) - 1;
1120 					break;
1121 				case '~':
1122 					if (O_ISSET(sp, O_MAGIC))
1123 						*t++ = '~';
1124 					else {
1125 						memcpy(t,
1126 						    sp->repl, sp->repl_len);
1127 						t += sp->repl_len;
1128 					}
1129 					break;
1130 				case '.':
1131 				case '[':
1132 				case '*':
1133 					if (O_ISSET(sp, O_MAGIC))
1134 						*t++ = '\\';
1135 					*t++ = *p;
1136 					break;
1137 				default:
1138 					*t++ = '\\';
1139 					*t++ = *p;
1140 				}
1141 			} else
1142 				*t++ = '\\';
1143 			break;
1144 		case '~':
1145 			if (O_ISSET(sp, O_MAGIC)) {
1146 				memcpy(t, sp->repl, sp->repl_len);
1147 				t += sp->repl_len;
1148 			} else
1149 				*t++ = '~';
1150 			break;
1151 		case '.':
1152 		case '[':
1153 		case '*':
1154 			if (!O_ISSET(sp, O_MAGIC))
1155 				*t++ = '\\';
1156 			*t++ = *p;
1157 			break;
1158 		default:
1159 			*t++ = *p;
1160 			break;
1161 		}
1162 
1163 	*ptrnp = bp;
1164 	*plenp = t - bp;
1165 	return (0);
1166 }
1167 
1168 /*
1169  * re_tag_conv --
1170  *	Convert a tags search path into something that the POSIX
1171  *	1003.2 RE functions can handle.
1172  */
1173 static int
1174 re_tag_conv(sp, ptrnp, plenp, replacedp)
1175 	SCR *sp;
1176 	char **ptrnp;
1177 	size_t *plenp;
1178 	int *replacedp;
1179 {
1180 	size_t blen, len;
1181 	int lastdollar;
1182 	char *bp, *p, *t;
1183 
1184 	len = *plenp;
1185 
1186 	/* Max memory usage is 2 times the length of the string. */
1187 	*replacedp = 1;
1188 	GET_SPACE_RET(sp, bp, blen, len * 2);
1189 
1190 	p = *ptrnp;
1191 	t = bp;
1192 
1193 	/* If the last character is a '/' or '?', we just strip it. */
1194 	if (len > 0 && (p[len - 1] == '/' || p[len - 1] == '?'))
1195 		--len;
1196 
1197 	/* If the next-to-last or last character is a '$', it's magic. */
1198 	if (len > 0 && p[len - 1] == '$') {
1199 		--len;
1200 		lastdollar = 1;
1201 	} else
1202 		lastdollar = 0;
1203 
1204 	/* If the first character is a '/' or '?', we just strip it. */
1205 	if (len > 0 && (p[0] == '/' || p[0] == '?')) {
1206 		++p;
1207 		--len;
1208 	}
1209 
1210 	/* If the first or second character is a '^', it's magic. */
1211 	if (p[0] == '^') {
1212 		*t++ = *p++;
1213 		--len;
1214 	}
1215 
1216 	/*
1217 	 * Escape every other magic character we can find, meanwhile stripping
1218 	 * the backslashes ctags inserts when escaping the search delimiter
1219 	 * characters.
1220 	 */
1221 	for (; len > 0; --len) {
1222 		if (p[0] == '\\' && (p[1] == '/' || p[1] == '?')) {
1223 			++p;
1224 			--len;
1225 		} else if (strchr("^.[]$*", p[0]))
1226 			*t++ = '\\';
1227 		*t++ = *p++;
1228 	}
1229 	if (lastdollar)
1230 		*t++ = '$';
1231 
1232 	*ptrnp = bp;
1233 	*plenp = t - bp;
1234 	return (0);
1235 }
1236 
1237 /*
1238  * re_cscope_conv --
1239  *	 Convert a cscope search path into something that the POSIX
1240  *      1003.2 RE functions can handle.
1241  */
1242 static int
1243 re_cscope_conv(sp, ptrnp, plenp, replacedp)
1244 	SCR *sp;
1245 	char **ptrnp;
1246 	size_t *plenp;
1247 	int *replacedp;
1248 {
1249 	size_t blen, len, nspaces;
1250 	char *bp, *p, *t;
1251 
1252 	/*
1253 	 * Each space in the source line printed by cscope represents an
1254 	 * arbitrary sequence of spaces, tabs, and comments.
1255 	 */
1256 #define	CSCOPE_RE_SPACE		"([ \t]|/\\*([^*]|\\*/)*\\*/)*"
1257 	for (nspaces = 0, p = *ptrnp, len = *plenp; len > 0; ++p, --len)
1258 		if (*p == ' ')
1259 			++nspaces;
1260 
1261 	/*
1262 	 * Allocate plenty of space:
1263 	 *	the string, plus potential escaping characters;
1264 	 *	nspaces + 2 copies of CSCOPE_RE_SPACE;
1265 	 *	^, $, nul terminator characters.
1266 	 */
1267 	*replacedp = 1;
1268 	len = (p - *ptrnp) * 2 + (nspaces + 2) * sizeof(CSCOPE_RE_SPACE) + 3;
1269 	GET_SPACE_RET(sp, bp, blen, len);
1270 
1271 	p = *ptrnp;
1272 	t = bp;
1273 
1274 	*t++ = '^';
1275 	memcpy(t, CSCOPE_RE_SPACE, sizeof(CSCOPE_RE_SPACE) - 1);
1276 	t += sizeof(CSCOPE_RE_SPACE) - 1;
1277 
1278 	for (len = *plenp; len > 0; ++p, --len)
1279 		if (*p == ' ') {
1280 			memcpy(t, CSCOPE_RE_SPACE, sizeof(CSCOPE_RE_SPACE) - 1);
1281 			t += sizeof(CSCOPE_RE_SPACE) - 1;
1282 		} else {
1283 			if (strchr("\\^.[]$*+?()|{}", *p))
1284 				*t++ = '\\';
1285 			*t++ = *p;
1286 		}
1287 
1288 	memcpy(t, CSCOPE_RE_SPACE, sizeof(CSCOPE_RE_SPACE) - 1);
1289 	t += sizeof(CSCOPE_RE_SPACE) - 1;
1290 	*t++ = '$';
1291 
1292 	*ptrnp = bp;
1293 	*plenp = t - bp;
1294 	return (0);
1295 }
1296 
1297 /*
1298  * re_error --
1299  *	Report a regular expression error.
1300  *
1301  * PUBLIC: void re_error __P((SCR *, int, regex_t *));
1302  */
1303 void
1304 re_error(sp, errcode, preg)
1305 	SCR *sp;
1306 	int errcode;
1307 	regex_t *preg;
1308 {
1309 	size_t s;
1310 	char *oe;
1311 
1312 	s = regerror(errcode, preg, "", 0);
1313 	if ((oe = malloc(s)) == NULL)
1314 		msgq(sp, M_SYSERR, NULL);
1315 	else {
1316 		(void)regerror(errcode, preg, oe, s);
1317 		msgq(sp, M_ERR, "RE error: %s", oe);
1318 		free(oe);
1319 	}
1320 }
1321 
1322 /*
1323  * re_sub --
1324  * 	Do the substitution for a regular expression.
1325  */
1326 static int
1327 re_sub(sp, ip, lbp, lbclenp, lblenp, match)
1328 	SCR *sp;
1329 	char *ip;			/* Input line. */
1330 	char **lbp;
1331 	size_t *lbclenp, *lblenp;
1332 	regmatch_t match[10];
1333 {
1334 	enum { C_NOTSET, C_LOWER, C_ONELOWER, C_ONEUPPER, C_UPPER } conv;
1335 	size_t lbclen, lblen;		/* Local copies. */
1336 	size_t mlen;			/* Match length. */
1337 	size_t rpl;			/* Remaining replacement length. */
1338 	char *rp;			/* Replacement pointer. */
1339 	int ch;
1340 	int no;				/* Match replacement offset. */
1341 	char *p, *t;			/* Buffer pointers. */
1342 	char *lb;			/* Local copies. */
1343 
1344 	lb = *lbp;			/* Get local copies. */
1345 	lbclen = *lbclenp;
1346 	lblen = *lblenp;
1347 
1348 	/*
1349 	 * QUOTING NOTE:
1350 	 *
1351 	 * There are some special sequences that vi provides in the
1352 	 * replacement patterns.
1353 	 *	 & string the RE matched (\& if nomagic set)
1354 	 *	\# n-th regular subexpression
1355 	 *	\E end \U, \L conversion
1356 	 *	\e end \U, \L conversion
1357 	 *	\l convert the next character to lower-case
1358 	 *	\L convert to lower-case, until \E, \e, or end of replacement
1359 	 *	\u convert the next character to upper-case
1360 	 *	\U convert to upper-case, until \E, \e, or end of replacement
1361 	 *
1362 	 * Otherwise, since this is the lowest level of replacement, discard
1363 	 * all escaping characters.  This (hopefully) matches historic practice.
1364 	 */
1365 #define	OUTCH(ch, nltrans) {						\
1366 	CHAR_T __ch = (ch);						\
1367 	u_int __value = KEY_VAL(sp, __ch);				\
1368 	if (nltrans && (__value == K_CR || __value == K_NL)) {		\
1369 		NEEDNEWLINE(sp);					\
1370 		sp->newl[sp->newl_cnt++] = lbclen;			\
1371 	} else if (conv != C_NOTSET) {					\
1372 		switch (conv) {						\
1373 		case C_ONELOWER:					\
1374 			conv = C_NOTSET;				\
1375 			/* FALLTHROUGH */				\
1376 		case C_LOWER:						\
1377 			if (isupper(__ch))				\
1378 				__ch = tolower(__ch);			\
1379 			break;						\
1380 		case C_ONEUPPER:					\
1381 			conv = C_NOTSET;				\
1382 			/* FALLTHROUGH */				\
1383 		case C_UPPER:						\
1384 			if (islower(__ch))				\
1385 				__ch = toupper(__ch);			\
1386 			break;						\
1387 		default:						\
1388 			abort();					\
1389 		}							\
1390 	}								\
1391 	NEEDSP(sp, 1, p);						\
1392 	*p++ = __ch;							\
1393 	++lbclen;							\
1394 }
1395 	conv = C_NOTSET;
1396 	for (rp = sp->repl, rpl = sp->repl_len, p = lb + lbclen; rpl--;) {
1397 		switch (ch = *rp++) {
1398 		case '&':
1399 			if (O_ISSET(sp, O_MAGIC)) {
1400 				no = 0;
1401 				goto subzero;
1402 			}
1403 			break;
1404 		case '\\':
1405 			if (rpl == 0)
1406 				break;
1407 			--rpl;
1408 			switch (ch = *rp) {
1409 			case '&':
1410 				++rp;
1411 				if (!O_ISSET(sp, O_MAGIC)) {
1412 					no = 0;
1413 					goto subzero;
1414 				}
1415 				break;
1416 			case '0': case '1': case '2': case '3': case '4':
1417 			case '5': case '6': case '7': case '8': case '9':
1418 				no = *rp++ - '0';
1419 subzero:			if (match[no].rm_so == -1 ||
1420 			    	    match[no].rm_eo == -1)
1421 					break;
1422 				mlen = match[no].rm_eo - match[no].rm_so;
1423 				for (t = ip + match[no].rm_so; mlen--; ++t)
1424 					OUTCH(*t, 0);
1425 				continue;
1426 			case 'e':
1427 			case 'E':
1428 				++rp;
1429 				conv = C_NOTSET;
1430 				continue;
1431 			case 'l':
1432 				++rp;
1433 				conv = C_ONELOWER;
1434 				continue;
1435 			case 'L':
1436 				++rp;
1437 				conv = C_LOWER;
1438 				continue;
1439 			case 'u':
1440 				++rp;
1441 				conv = C_ONEUPPER;
1442 				continue;
1443 			case 'U':
1444 				++rp;
1445 				conv = C_UPPER;
1446 				continue;
1447 			default:
1448 				++rp;
1449 				break;
1450 			}
1451 		}
1452 		OUTCH(ch, 1);
1453 	}
1454 
1455 	*lbp = lb;			/* Update caller's information. */
1456 	*lbclenp = lbclen;
1457 	*lblenp = lblen;
1458 	return (0);
1459 }
1460