xref: /illumos-gate/usr/src/cmd/sed/process.c (revision 0a1278f26ea4b7c8c0285d4f2d6c5b680904aa01)
1 /*
2  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
3  * Copyright (c) 1992 Diomidis Spinellis.
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Diomidis Spinellis of Imperial College, University of London.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 
38 #include <ctype.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <limits.h>
43 #include <regex.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <wchar.h>
49 #include <wctype.h>
50 #include <termio.h>
51 #include <libintl.h>
52 #include <note.h>
53 
54 #include "defs.h"
55 #include "extern.h"
56 
57 static SPACE HS, PS, SS, YS;
58 #define	pd		PS.deleted
59 #define	ps		PS.space
60 #define	psl		PS.len
61 #define	hs		HS.space
62 #define	hsl		HS.len
63 
64 static int	applies(struct s_command *);
65 static void	do_tr(struct s_tr *);
66 static void	flush_appends(void);
67 static void	lputs(char *, size_t);
68 static int	 regexec_e(regex_t *, const char *, int, int, size_t);
69 static void	regsub(SPACE *, char *, char *);
70 static int	substitute(struct s_command *);
71 
72 struct s_appends *appends;	/* Array of pointers to strings to append. */
73 static int appendx;		/* Index into appends array. */
74 int appendnum;			/* Size of appends array. */
75 
76 static int lastaddr;		/* Set by applies if last address of a range. */
77 static int sdone;		/* If any substitutes since last line input. */
78 				/* Iov structure for 'w' commands. */
79 static regex_t *defpreg;
80 size_t maxnsub;
81 regmatch_t *match;
82 
83 #define	OUT() do {					\
84 	(void) fwrite(ps, 1, psl, outfile);		\
85 	(void) fputc('\n', outfile);			\
86 	_NOTE(CONSTCOND)				\
87 } while (0)
88 
89 void
90 process(void)
91 {
92 	struct s_command *cp;
93 	SPACE tspace;
94 	size_t oldpsl = 0;
95 	char *p;
96 
97 	p = NULL;
98 
99 	for (linenum = 0; mf_fgets(&PS, REPLACE); /* NOP */) {
100 		pd = 0;
101 top:
102 		cp = prog;
103 redirect:
104 		while (cp != NULL) {
105 			if (!applies(cp)) {
106 				cp = cp->next;
107 				continue;
108 			}
109 			switch (cp->code) {
110 			case '{':
111 				cp = cp->u.c;
112 				goto redirect;
113 			case 'a':
114 				if (appendx >= appendnum)
115 					if ((appends = realloc(appends,
116 					    sizeof (struct s_appends) *
117 					    (appendnum *= 2))) == NULL)
118 						err(1, "realloc");
119 				appends[appendx].type = AP_STRING;
120 				appends[appendx].s = cp->t;
121 				appends[appendx].len = strlen(cp->t);
122 				appendx++;
123 				break;
124 			case 'b':
125 				cp = cp->u.c;
126 				goto redirect;
127 			case 'c':
128 				pd = 1;
129 				psl = 0;
130 				if (cp->a2 == NULL || lastaddr || lastline())
131 					(void) fprintf(outfile, "%s", cp->t);
132 				break;
133 			case 'd':
134 				pd = 1;
135 				goto new;
136 			case 'D':
137 				if (pd)
138 					goto new;
139 				if (psl == 0 ||
140 				    (p = memchr(ps, '\n', psl)) == NULL) {
141 					pd = 1;
142 					goto new;
143 				} else {
144 					psl -=
145 					    (uintptr_t)(p + 1) - (uintptr_t)ps;
146 					(void) memmove(ps, p + 1, psl);
147 					goto top;
148 				}
149 			case 'g':
150 				cspace(&PS, hs, hsl, REPLACE);
151 				break;
152 			case 'G':
153 				cspace(&PS, "\n", 1, APPEND);
154 				cspace(&PS, hs, hsl, APPEND);
155 				break;
156 			case 'h':
157 				cspace(&HS, ps, psl, REPLACE);
158 				break;
159 			case 'H':
160 				cspace(&HS, "\n", 1, APPEND);
161 				cspace(&HS, ps, psl, APPEND);
162 				break;
163 			case 'i':
164 				(void) fprintf(outfile, "%s", cp->t);
165 				break;
166 			case 'l':
167 				lputs(ps, psl);
168 				break;
169 			case 'n':
170 				if (!nflag && !pd)
171 					OUT();
172 				flush_appends();
173 				if (!mf_fgets(&PS, REPLACE))
174 					exit(0);
175 				pd = 0;
176 				break;
177 			case 'N':
178 				flush_appends();
179 				cspace(&PS, "\n", 1, APPEND);
180 				if (!mf_fgets(&PS, APPEND))
181 					exit(0);
182 				break;
183 			case 'p':
184 				if (pd)
185 					break;
186 				OUT();
187 				break;
188 			case 'P':
189 				if (pd)
190 					break;
191 				if ((p = memchr(ps, '\n', psl)) != NULL) {
192 					oldpsl = psl;
193 					psl = (uintptr_t)p - (uintptr_t)ps;
194 				}
195 				OUT();
196 				if (p != NULL)
197 					psl = oldpsl;
198 				break;
199 			case 'q':
200 				if (!nflag && !pd)
201 					OUT();
202 				flush_appends();
203 				exit(0);
204 				/*NOTREACHED*/
205 			case 'r':
206 				if (appendx >= appendnum)
207 					if ((appends = realloc(appends,
208 					    sizeof (struct s_appends) *
209 					    (appendnum *= 2))) == NULL)
210 						err(1, "realloc");
211 				appends[appendx].type = AP_FILE;
212 				appends[appendx].s = cp->t;
213 				appends[appendx].len = strlen(cp->t);
214 				appendx++;
215 				break;
216 			case 's':
217 				sdone |= substitute(cp);
218 				break;
219 			case 't':
220 				if (sdone) {
221 					sdone = 0;
222 					cp = cp->u.c;
223 					goto redirect;
224 				}
225 				break;
226 			case 'w':
227 				if (pd)
228 					break;
229 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
230 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 0666))
231 				    == -1)
232 					err(1, "%s", cp->t);
233 				if (write(cp->u.fd, ps, psl) != (ssize_t)psl ||
234 				    write(cp->u.fd, "\n", 1) != 1)
235 					err(1, "%s", cp->t);
236 				break;
237 			case 'x':
238 				/*
239 				 * If the hold space is null, make it empty
240 				 * but not null.  Otherwise the pattern space
241 				 * will become null after the swap, which is
242 				 * an abnormal condition.
243 				 */
244 				if (hs == NULL)
245 					cspace(&HS, "", 0, REPLACE);
246 				tspace = PS;
247 				PS = HS;
248 				HS = tspace;
249 				break;
250 			case 'y':
251 				if (pd || psl == 0)
252 					break;
253 				do_tr(cp->u.y);
254 				break;
255 			case ':':
256 			case '}':
257 				break;
258 			case '=':
259 				(void) fprintf(outfile, "%lu\n", linenum);
260 			}
261 			cp = cp->next;
262 		} /* for all cp */
263 
264 new:		if (!nflag && !pd)
265 			OUT();
266 		flush_appends();
267 	} /* for all lines */
268 }
269 
270 /*
271  * TRUE if the address passed matches the current program state
272  * (lastline, linenumber, ps).
273  */
274 #define	MATCH(a)							\
275 	((a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
276 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline())
277 
278 /*
279  * Return TRUE if the command applies to the current line.  Sets the start
280  * line for process ranges.  Interprets the non-select (``!'') flag.
281  */
282 static int
283 applies(struct s_command *cp)
284 {
285 	int r;
286 
287 	lastaddr = 0;
288 	if (cp->a1 == NULL && cp->a2 == NULL)
289 		r = 1;
290 	else if (cp->a2)
291 		if (cp->startline > 0) {
292 			if (MATCH(cp->a2)) {
293 				cp->startline = 0;
294 				lastaddr = 1;
295 				r = 1;
296 			} else if (linenum - cp->startline <= cp->a2->u.l)
297 				r = 1;
298 			else if ((cp->a2->type == AT_LINE &&
299 			    linenum > cp->a2->u.l) ||
300 			    (cp->a2->type == AT_RELLINE &&
301 			    linenum - cp->startline > cp->a2->u.l)) {
302 				/*
303 				 * We missed the 2nd address due to a branch,
304 				 * so just close the range and return false.
305 				 */
306 				cp->startline = 0;
307 				r = 0;
308 			} else
309 				r = 1;
310 		} else if (MATCH(cp->a1)) {
311 			/*
312 			 * If the second address is a number less than or
313 			 * equal to the line number first selected, only
314 			 * one line shall be selected.
315 			 *	-- POSIX 1003.2
316 			 * Likewise if the relative second line address is zero.
317 			 */
318 			if ((cp->a2->type == AT_LINE &&
319 			    linenum >= cp->a2->u.l) ||
320 			    (cp->a2->type == AT_RELLINE && cp->a2->u.l == 0))
321 				lastaddr = 1;
322 			else {
323 				cp->startline = linenum;
324 			}
325 			r = 1;
326 		} else
327 			r = 0;
328 	else
329 		r = MATCH(cp->a1);
330 	return (cp->nonsel ? ! r : r);
331 }
332 
333 /*
334  * Reset the sed processor to its initial state.
335  */
336 void
337 resetstate(void)
338 {
339 	struct s_command *cp;
340 
341 	/*
342 	 * Reset all in-range markers.
343 	 */
344 	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
345 		if (cp->a2)
346 			cp->startline = 0;
347 
348 	/*
349 	 * Clear out the hold space.
350 	 */
351 	cspace(&HS, "", 0, REPLACE);
352 }
353 
354 /*
355  * substitute --
356  *	Do substitutions in the pattern space.  Currently, we build a
357  *	copy of the new pattern space in the substitute space structure
358  *	and then swap them.
359  */
360 static int
361 substitute(struct s_command *cp)
362 {
363 	SPACE tspace;
364 	regex_t *re;
365 	regoff_t re_off, slen;
366 	int lastempty, n;
367 	char *s;
368 
369 	s = ps;
370 	re = cp->u.s->re;
371 	if (re == NULL) {
372 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
373 			linenum = cp->u.s->linenum;
374 			fatal(_("\\%u not defined in the RE"),
375 			    cp->u.s->maxbref);
376 		}
377 	}
378 	if (!regexec_e(re, s, 0, 0, psl))
379 		return (0);
380 
381 	SS.len = 0;				/* Clean substitute space. */
382 	slen = psl;
383 	n = cp->u.s->n;
384 	lastempty = 1;
385 
386 	switch (n) {
387 	case 0:					/* Global */
388 		do {
389 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
390 				/* Locate start of replaced string. */
391 				re_off = match[0].rm_so;
392 				/* Copy leading retained string. */
393 				cspace(&SS, s, re_off, APPEND);
394 				/* Add in regular expression. */
395 				regsub(&SS, s, cp->u.s->new);
396 			}
397 
398 			/* Move past this match. */
399 			if (match[0].rm_so != match[0].rm_eo) {
400 				s += match[0].rm_eo;
401 				slen -= match[0].rm_eo;
402 				lastempty = 0;
403 			} else {
404 				if (match[0].rm_so < slen)
405 					cspace(&SS, s + match[0].rm_so, 1,
406 					    APPEND);
407 				s += match[0].rm_so + 1;
408 				slen -= match[0].rm_so + 1;
409 				lastempty = 1;
410 			}
411 		} while (slen >= 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
412 		/* Copy trailing retained string. */
413 		if (slen > 0)
414 			cspace(&SS, s, slen, APPEND);
415 		break;
416 	default:				/* Nth occurrence */
417 		while (--n) {
418 			if (match[0].rm_eo == match[0].rm_so)
419 				match[0].rm_eo = match[0].rm_so + 1;
420 			s += match[0].rm_eo;
421 			slen -= match[0].rm_eo;
422 			if (slen < 0)
423 				return (0);
424 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
425 				return (0);
426 		}
427 		/* FALLTHROUGH */
428 	case 1:					/* 1st occurrence */
429 		/* Locate start of replaced string. */
430 		re_off = match[0].rm_so + ((uintptr_t)s - (uintptr_t)ps);
431 		/* Copy leading retained string. */
432 		cspace(&SS, ps, re_off, APPEND);
433 		/* Add in regular expression. */
434 		regsub(&SS, s, cp->u.s->new);
435 		/* Copy trailing retained string. */
436 		s += match[0].rm_eo;
437 		slen -= match[0].rm_eo;
438 		cspace(&SS, s, slen, APPEND);
439 		break;
440 	}
441 
442 	/*
443 	 * Swap the substitute space and the pattern space, and make sure
444 	 * that any leftover pointers into stdio memory get lost.
445 	 */
446 	tspace = PS;
447 	PS = SS;
448 	SS = tspace;
449 	SS.space = SS.back;
450 
451 	/* Handle the 'p' flag. */
452 	if (cp->u.s->p)
453 		OUT();
454 
455 	/* Handle the 'w' flag. */
456 	if (cp->u.s->wfile && !pd) {
457 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
458 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 0666)) == -1)
459 			err(1, "%s", cp->u.s->wfile);
460 		if (write(cp->u.s->wfd, ps, psl) != (ssize_t)psl ||
461 		    write(cp->u.s->wfd, "\n", 1) != 1)
462 			err(1, "%s", cp->u.s->wfile);
463 	}
464 	return (1);
465 }
466 
467 /*
468  * do_tr --
469  *	Perform translation ('y' command) in the pattern space.
470  */
471 static void
472 do_tr(struct s_tr *y)
473 {
474 	SPACE tmp;
475 	char c, *p;
476 	size_t clen, left;
477 	int i;
478 
479 	if (MB_CUR_MAX == 1) {
480 		/*
481 		 * Single-byte encoding: perform in-place translation
482 		 * of the pattern space.
483 		 */
484 		for (p = ps; p < &ps[psl]; p++)
485 			*p = y->bytetab[(uchar_t)*p];
486 	} else {
487 		/*
488 		 * Multi-byte encoding: perform translation into the
489 		 * translation space, then swap the translation and
490 		 * pattern spaces.
491 		 */
492 		/* Clean translation space. */
493 		YS.len = 0;
494 		for (p = ps, left = psl; left > 0; p += clen, left -= clen) {
495 			if ((c = y->bytetab[(uchar_t)*p]) != '\0') {
496 				cspace(&YS, &c, 1, APPEND);
497 				clen = 1;
498 				continue;
499 			}
500 			for (i = 0; i < y->nmultis; i++)
501 				if (left >= y->multis[i].fromlen &&
502 				    memcmp(p, y->multis[i].from,
503 				    y->multis[i].fromlen) == 0)
504 					break;
505 			if (i < y->nmultis) {
506 				cspace(&YS, y->multis[i].to,
507 				    y->multis[i].tolen, APPEND);
508 				clen = y->multis[i].fromlen;
509 			} else {
510 				cspace(&YS, p, 1, APPEND);
511 				clen = 1;
512 			}
513 		}
514 		/* Swap the translation space and the pattern space. */
515 		tmp = PS;
516 		PS = YS;
517 		YS = tmp;
518 		YS.space = YS.back;
519 	}
520 }
521 
522 /*
523  * Flush append requests.  Always called before reading a line,
524  * therefore it also resets the substitution done (sdone) flag.
525  */
526 static void
527 flush_appends(void)
528 {
529 	FILE *f;
530 	int count, i;
531 	char buf[8 * 1024];
532 
533 	for (i = 0; i < appendx; i++)
534 		switch (appends[i].type) {
535 		case AP_STRING:
536 			(void) fwrite(appends[i].s, sizeof (char),
537 			    appends[i].len, outfile);
538 			break;
539 		case AP_FILE:
540 			/*
541 			 * Read files probably shouldn't be cached.  Since
542 			 * it's not an error to read a non-existent file,
543 			 * it's possible that another program is interacting
544 			 * with the sed script through the filesystem.  It
545 			 * would be truly bizarre, but possible.  It's probably
546 			 * not that big a performance win, anyhow.
547 			 */
548 			if ((f = fopen(appends[i].s, "r")) == NULL)
549 				break;
550 			while ((count =
551 			    fread(buf, sizeof (char), sizeof (buf), f)))
552 				(void) fwrite(buf, sizeof (char), count,
553 				    outfile);
554 			(void) fclose(f);
555 			break;
556 		}
557 	if (ferror(outfile))
558 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
559 	appendx = sdone = 0;
560 }
561 
562 static void
563 lputs(char *s, size_t len)
564 {
565 	static const char escapes[] = "\\\a\b\f\r\t\v";
566 	int c, col, width;
567 	const char *p;
568 	struct winsize win;
569 	static int termwidth = -1;
570 	size_t clen, i;
571 	wchar_t wc;
572 	mbstate_t mbs;
573 
574 	if (outfile != stdout)
575 		termwidth = 60;
576 	if (termwidth == -1) {
577 		if (((p = getenv("COLUMNS")) != NULL) && (*p != '\0'))
578 			termwidth = atoi(p);
579 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
580 		    win.ws_col > 0)
581 			termwidth = win.ws_col;
582 		else
583 			termwidth = 60;
584 	}
585 	if (termwidth <= 0)
586 		termwidth = 1;
587 
588 	(void) memset(&mbs, 0, sizeof (mbs));
589 	col = 0;
590 	while (len != 0) {
591 		clen = mbrtowc(&wc, s, len, &mbs);
592 		if (clen == 0)
593 			clen = 1;
594 		if (clen == (size_t)-1 || clen == (size_t)-2) {
595 			wc = (unsigned char)*s;
596 			clen = 1;
597 			(void) memset(&mbs, 0, sizeof (mbs));
598 		}
599 		if (wc == '\n') {
600 			if (col + 1 >= termwidth)
601 				(void) fprintf(outfile, "\\\n");
602 			(void) fputc('$', outfile);
603 			(void) fputc('\n', outfile);
604 			col = 0;
605 		} else if (iswprint(wc)) {
606 			width = wcwidth(wc);
607 			if (col + width >= termwidth) {
608 				(void) fprintf(outfile, "\\\n");
609 				col = 0;
610 			}
611 			(void) fwrite(s, 1, clen, outfile);
612 			col += width;
613 		} else if (wc != L'\0' && (c = wctob(wc)) != EOF &&
614 		    (p = strchr(escapes, c)) != NULL) {
615 			if (col + 2 >= termwidth) {
616 				(void) fprintf(outfile, "\\\n");
617 				col = 0;
618 			}
619 			(void) fprintf(outfile, "\\%c",
620 			    "\\abfrtv"[(uintptr_t)p - (uintptr_t)escapes]);
621 			col += 2;
622 		} else {
623 			if (col + 4 * clen >= (unsigned)termwidth) {
624 				(void) fprintf(outfile, "\\\n");
625 				col = 0;
626 			}
627 			for (i = 0; i < clen; i++)
628 				(void) fprintf(outfile, "\\%03o",
629 				    (int)(unsigned char)s[i]);
630 			col += 4 * clen;
631 		}
632 		s += clen;
633 		len -= clen;
634 	}
635 	if (col + 1 >= termwidth)
636 		(void) fprintf(outfile, "\\\n");
637 	(void) fputc('$', outfile);
638 	(void) fputc('\n', outfile);
639 	if (ferror(outfile))
640 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
641 }
642 
643 static int
644 regexec_e(regex_t *preg, const char *string, int eflags, int nomatch,
645 	size_t slen)
646 {
647 	int eval;
648 
649 	if (preg == NULL) {
650 		if (defpreg == NULL)
651 			fatal(_("first RE may not be empty"));
652 	} else
653 		defpreg = preg;
654 
655 	/* Set anchors */
656 	match[0].rm_so = 0;
657 	match[0].rm_eo = slen;
658 
659 	eval = regexec(defpreg, string,
660 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
661 	switch (eval) {
662 	case 0:
663 		return (1);
664 	case REG_NOMATCH:
665 		return (0);
666 	}
667 	fatal(_("RE error: %s"), strregerror(eval, defpreg));
668 	return (0);
669 }
670 
671 /*
672  * regsub - perform substitutions after a regexp match
673  * Based on a routine by Henry Spencer
674  */
675 static void
676 regsub(SPACE *sp, char *string, char *src)
677 {
678 	int len, no;
679 	char c, *dst;
680 
681 #define	NEEDSP(reqlen)							\
682 	/* XXX What is the +1 for? */					\
683 	if (sp->len + (reqlen) + 1 >= sp->blen) {			\
684 		sp->blen += (reqlen) + 1024;				\
685 		if ((sp->back = realloc(sp->back, sp->blen)) == NULL)	\
686 			err(1, "realloc");				\
687 		sp->space = sp->back;					\
688 		dst = sp->space + sp->len;				\
689 	}
690 
691 	dst = sp->space + sp->len;
692 	while ((c = *src++) != '\0') {
693 		if (c == '&')
694 			no = 0;
695 		else if (c == '\\' && isdigit((unsigned char)*src))
696 			no = *src++ - '0';
697 		else
698 			no = -1;
699 		if (no < 0) {		/* Ordinary character. */
700 			if (c == '\\' && (*src == '\\' || *src == '&'))
701 				c = *src++;
702 			NEEDSP(1);
703 			*dst++ = c;
704 			++sp->len;
705 		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
706 			len = match[no].rm_eo - match[no].rm_so;
707 			NEEDSP(len);
708 			(void) memmove(dst, string + match[no].rm_so, len);
709 			dst += len;
710 			sp->len += len;
711 		}
712 	}
713 	NEEDSP(1);
714 	*dst = '\0';
715 }
716 
717 /*
718  * cspace --
719  *	Concatenate space: append the source space to the destination space,
720  *	allocating new space as necessary.
721  */
722 void
723 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
724 {
725 	size_t tlen;
726 
727 	/* Make sure SPACE has enough memory and ramp up quickly. */
728 	tlen = sp->len + len + 1;
729 	if (tlen > sp->blen) {
730 		sp->blen = tlen + 1024;
731 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
732 		    NULL)
733 			err(1, "realloc");
734 	}
735 
736 	if (spflag == REPLACE)
737 		sp->len = 0;
738 
739 	(void) memmove(sp->space + sp->len, p, len);
740 
741 	sp->space[sp->len += len] = '\0';
742 }
743 
744 /*
745  * Close all cached opened files and report any errors
746  */
747 void
748 cfclose(struct s_command *cp, struct s_command *end)
749 {
750 
751 	for (; cp != end; cp = cp->next)
752 		switch (cp->code) {
753 		case 's':
754 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
755 				err(1, "%s", cp->u.s->wfile);
756 			cp->u.s->wfd = -1;
757 			break;
758 		case 'w':
759 			if (cp->u.fd != -1 && close(cp->u.fd))
760 				err(1, "%s", cp->t);
761 			cp->u.fd = -1;
762 			break;
763 		case '{':
764 			cfclose(cp->u.c, cp->next);
765 			break;
766 		}
767 }
768