xref: /freebsd/usr.bin/sed/process.c (revision ea825d02749f382c3f7e17f28247f20a48733eab)
1 /*-
2  * Copyright (c) 1992 Diomidis Spinellis.
3  * Copyright (c) 1992, 1993, 1994
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Diomidis Spinellis of Imperial College, University of London.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #ifndef lint
38 static const char sccsid[] = "@(#)process.c	8.6 (Berkeley) 4/20/94";
39 #endif
40 
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 #include <sys/ioctl.h>
44 #include <sys/uio.h>
45 
46 #include <ctype.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <limits.h>
51 #include <regex.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <wchar.h>
57 #include <wctype.h>
58 
59 #include "defs.h"
60 #include "extern.h"
61 
62 static SPACE HS, PS, SS, YS;
63 #define	pd		PS.deleted
64 #define	ps		PS.space
65 #define	psl		PS.len
66 #define	psanl		PS.append_newline
67 #define	hs		HS.space
68 #define	hsl		HS.len
69 
70 static inline int	 applies(struct s_command *);
71 static void		 do_tr(struct s_tr *);
72 static void		 flush_appends(void);
73 static void		 lputs(char *, size_t);
74 static int		 regexec_e(regex_t *, const char *, int, int, size_t,
75 			     size_t);
76 static void		 regsub(SPACE *, char *, char *);
77 static int		 substitute(struct s_command *);
78 
79 struct s_appends *appends;	/* Array of pointers to strings to append. */
80 static int appendx;		/* Index into appends array. */
81 int appendnum;			/* Size of appends array. */
82 
83 static int lastaddr;		/* Set by applies if last address of a range. */
84 static int sdone;		/* If any substitutes since last line input. */
85 				/* Iov structure for 'w' commands. */
86 static regex_t *defpreg;
87 size_t maxnsub;
88 regmatch_t *match;
89 
90 #define OUT() do {							\
91 	fwrite(ps, 1, psl, outfile);					\
92 	if (psanl) fputc('\n', outfile);				\
93 } while (0)
94 
95 void
96 process(void)
97 {
98 	struct s_command *cp;
99 	SPACE tspace;
100 	size_t oldpsl;
101 	char *p;
102 	int oldpsanl;
103 
104 	p = NULL;
105 	oldpsanl = oldpsl = 0;
106 
107 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
108 		pd = 0;
109 top:
110 		cp = prog;
111 redirect:
112 		while (cp != NULL) {
113 			if (!applies(cp)) {
114 				cp = cp->next;
115 				continue;
116 			}
117 			switch (cp->code) {
118 			case '{':
119 				cp = cp->u.c;
120 				goto redirect;
121 			case 'a':
122 				if (appendx >= appendnum)
123 					if ((appends = realloc(appends,
124 					    sizeof(struct s_appends) *
125 					    (appendnum *= 2))) == NULL)
126 						err(1, "realloc");
127 				appends[appendx].type = AP_STRING;
128 				appends[appendx].s = cp->t;
129 				appends[appendx].len = strlen(cp->t);
130 				appendx++;
131 				break;
132 			case 'b':
133 				cp = cp->u.c;
134 				goto redirect;
135 			case 'c':
136 				pd = 1;
137 				psl = 0;
138 				if (cp->a2 == NULL || lastaddr || lastline())
139 					(void)fprintf(outfile, "%s", cp->t);
140 				break;
141 			case 'd':
142 				pd = 1;
143 				goto new;
144 			case 'D':
145 				if (pd)
146 					goto new;
147 				if (psl == 0 ||
148 				    (p = memchr(ps, '\n', psl)) == NULL) {
149 					pd = 1;
150 					goto new;
151 				} else {
152 					psl -= (p + 1) - ps;
153 					memmove(ps, p + 1, psl);
154 					goto top;
155 				}
156 			case 'g':
157 				cspace(&PS, hs, hsl, REPLACE);
158 				break;
159 			case 'G':
160 				cspace(&PS, "\n", 1, APPEND);
161 				cspace(&PS, hs, hsl, APPEND);
162 				break;
163 			case 'h':
164 				cspace(&HS, ps, psl, REPLACE);
165 				break;
166 			case 'H':
167 				cspace(&HS, "\n", 1, APPEND);
168 				cspace(&HS, ps, psl, APPEND);
169 				break;
170 			case 'i':
171 				(void)fprintf(outfile, "%s", cp->t);
172 				break;
173 			case 'l':
174 				lputs(ps, psl);
175 				break;
176 			case 'n':
177 				if (!nflag && !pd)
178 					OUT();
179 				flush_appends();
180 				if (!mf_fgets(&PS, REPLACE))
181 					exit(0);
182 				pd = 0;
183 				break;
184 			case 'N':
185 				flush_appends();
186 				cspace(&PS, "\n", 1, APPEND);
187 				if (!mf_fgets(&PS, APPEND))
188 					exit(0);
189 				break;
190 			case 'p':
191 				if (pd)
192 					break;
193 				OUT();
194 				break;
195 			case 'P':
196 				if (pd)
197 					break;
198 				if ((p = memchr(ps, '\n', psl)) != NULL) {
199 					oldpsl = psl;
200 					oldpsanl = psanl;
201 					psl = p - ps;
202 					psanl = 1;
203 				}
204 				OUT();
205 				if (p != NULL) {
206 					psl = oldpsl;
207 					psanl = oldpsanl;
208 				}
209 				break;
210 			case 'q':
211 				if (!nflag && !pd)
212 					OUT();
213 				flush_appends();
214 				exit(0);
215 			case 'r':
216 				if (appendx >= appendnum)
217 					if ((appends = realloc(appends,
218 					    sizeof(struct s_appends) *
219 					    (appendnum *= 2))) == NULL)
220 						err(1, "realloc");
221 				appends[appendx].type = AP_FILE;
222 				appends[appendx].s = cp->t;
223 				appends[appendx].len = strlen(cp->t);
224 				appendx++;
225 				break;
226 			case 's':
227 				sdone |= substitute(cp);
228 				break;
229 			case 't':
230 				if (sdone) {
231 					sdone = 0;
232 					cp = cp->u.c;
233 					goto redirect;
234 				}
235 				break;
236 			case 'w':
237 				if (pd)
238 					break;
239 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
240 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
241 				    DEFFILEMODE)) == -1)
242 					err(1, "%s", cp->t);
243 				if (write(cp->u.fd, ps, psl) != (ssize_t)psl ||
244 				    write(cp->u.fd, "\n", 1) != 1)
245 					err(1, "%s", cp->t);
246 				break;
247 			case 'x':
248 				/*
249 				 * If the hold space is null, make it empty
250 				 * but not null.  Otherwise the pattern space
251 				 * will become null after the swap, which is
252 				 * an abnormal condition.
253 				 */
254 				if (hs == NULL)
255 					cspace(&HS, "", 0, REPLACE);
256 				tspace = PS;
257 				PS = HS;
258 				psanl = tspace.append_newline;
259 				HS = tspace;
260 				break;
261 			case 'y':
262 				if (pd || psl == 0)
263 					break;
264 				do_tr(cp->u.y);
265 				break;
266 			case ':':
267 			case '}':
268 				break;
269 			case '=':
270 				(void)fprintf(outfile, "%lu\n", linenum);
271 			}
272 			cp = cp->next;
273 		} /* for all cp */
274 
275 new:		if (!nflag && !pd)
276 			OUT();
277 		flush_appends();
278 	} /* for all lines */
279 }
280 
281 /*
282  * TRUE if the address passed matches the current program state
283  * (lastline, linenumber, ps).
284  */
285 #define	MATCH(a)							\
286 	((a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, 0, psl) :	\
287 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline())
288 
289 /*
290  * Return TRUE if the command applies to the current line.  Sets the start
291  * line for process ranges.  Interprets the non-select (``!'') flag.
292  */
293 static inline int
294 applies(struct s_command *cp)
295 {
296 	int r;
297 
298 	lastaddr = 0;
299 	if (cp->a1 == NULL && cp->a2 == NULL)
300 		r = 1;
301 	else if (cp->a2)
302 		if (cp->startline > 0) {
303                         switch (cp->a2->type) {
304                         case AT_RELLINE:
305                                 if (linenum - cp->startline <= cp->a2->u.l)
306                                         r = 1;
307                                 else {
308 				        cp->startline = 0;
309 				        r = 0;
310                                 }
311                                 break;
312                         default:
313                                 if (MATCH(cp->a2)) {
314                                         cp->startline = 0;
315                                         lastaddr = 1;
316                                         r = 1;
317                                 } else if (cp->a2->type == AT_LINE &&
318                                             linenum > cp->a2->u.l) {
319                                         /*
320                                          * We missed the 2nd address due to a
321                                          * branch, so just close the range and
322                                          * return false.
323                                          */
324                                         cp->startline = 0;
325                                         r = 0;
326                                 } else
327                                         r = 1;
328                         }
329 		} else if (cp->a1 && MATCH(cp->a1)) {
330 			/*
331 			 * If the second address is a number less than or
332 			 * equal to the line number first selected, only
333 			 * one line shall be selected.
334 			 *	-- POSIX 1003.2
335 			 * Likewise if the relative second line address is zero.
336 			 */
337 			if ((cp->a2->type == AT_LINE &&
338 			    linenum >= cp->a2->u.l) ||
339 			    (cp->a2->type == AT_RELLINE && cp->a2->u.l == 0))
340 				lastaddr = 1;
341 			else {
342 				cp->startline = linenum;
343 			}
344 			r = 1;
345 		} else
346 			r = 0;
347 	else
348 		r = MATCH(cp->a1);
349 	return (cp->nonsel ? ! r : r);
350 }
351 
352 /*
353  * Reset the sed processor to its initial state.
354  */
355 void
356 resetstate(void)
357 {
358 	struct s_command *cp;
359 
360 	/*
361 	 * Reset all in-range markers.
362 	 */
363 	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
364 		if (cp->a2)
365 			cp->startline = 0;
366 
367 	/*
368 	 * Clear out the hold space.
369 	 */
370 	cspace(&HS, "", 0, REPLACE);
371 }
372 
373 /*
374  * substitute --
375  *	Do substitutions in the pattern space.  Currently, we build a
376  *	copy of the new pattern space in the substitute space structure
377  *	and then swap them.
378  */
379 static int
380 substitute(struct s_command *cp)
381 {
382 	SPACE tspace;
383 	regex_t *re;
384 	regoff_t slen;
385 	int lastempty, n;
386 	size_t le = 0;
387 	char *s;
388 
389 	s = ps;
390 	re = cp->u.s->re;
391 	if (re == NULL) {
392 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
393 			linenum = cp->u.s->linenum;
394 			errx(1, "%lu: %s: \\%u not defined in the RE",
395 					linenum, fname, cp->u.s->maxbref);
396 		}
397 	}
398 	if (!regexec_e(re, ps, 0, 0, 0, psl))
399 		return (0);
400 
401 	SS.len = 0;				/* Clean substitute space. */
402 	slen = psl;
403 	n = cp->u.s->n;
404 	lastempty = 1;
405 
406 	do {
407 		/* Copy the leading retained string. */
408 		if (n <= 1 && (match[0].rm_so > le))
409 			cspace(&SS, s, match[0].rm_so - le, APPEND);
410 
411 		/* Skip zero-length matches right after other matches. */
412 		if (lastempty || (match[0].rm_so - le) ||
413 		    match[0].rm_so != match[0].rm_eo) {
414 			if (n <= 1) {
415 				/* Want this match: append replacement. */
416 				regsub(&SS, ps, cp->u.s->new);
417 				if (n == 1)
418 					n = -1;
419 			} else {
420 				/* Want a later match: append original. */
421 				if (match[0].rm_eo - le)
422 					cspace(&SS, s, match[0].rm_eo - le,
423 					    APPEND);
424 				n--;
425 			}
426 		}
427 
428 		/* Move past this match. */
429 		s = ps + match[0].rm_eo;
430 		slen = psl - match[0].rm_eo;
431 		le = match[0].rm_eo;
432 
433 		/*
434 		 * After a zero-length match, advance one byte,
435 		 * and at the end of the line, terminate.
436 		 */
437 		if (match[0].rm_so == match[0].rm_eo) {
438 			if (*s == '\0' || *s == '\n')
439 				slen = -1;
440 			else
441 				slen--;
442 			if (*s != '\0') {
443 			 	cspace(&SS, s++, 1, APPEND);
444 				le++;
445 			}
446 			lastempty = 1;
447 		} else
448 			lastempty = 0;
449 
450 	} while (n >= 0 && slen >= 0 &&
451 	    regexec_e(re, ps, REG_NOTBOL, 0, le, psl));
452 
453 	/* Did not find the requested number of matches. */
454 	if (n > 0)
455 		return (0);
456 
457 	/* Copy the trailing retained string. */
458 	if (slen > 0)
459 		cspace(&SS, s, slen, APPEND);
460 
461 	/*
462 	 * Swap the substitute space and the pattern space, and make sure
463 	 * that any leftover pointers into stdio memory get lost.
464 	 */
465 	tspace = PS;
466 	PS = SS;
467 	psanl = tspace.append_newline;
468 	SS = tspace;
469 	SS.space = SS.back;
470 
471 	/* Handle the 'p' flag. */
472 	if (cp->u.s->p)
473 		OUT();
474 
475 	/* Handle the 'w' flag. */
476 	if (cp->u.s->wfile && !pd) {
477 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
478 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
479 			err(1, "%s", cp->u.s->wfile);
480 		if (write(cp->u.s->wfd, ps, psl) != (ssize_t)psl ||
481 		    write(cp->u.s->wfd, "\n", 1) != 1)
482 			err(1, "%s", cp->u.s->wfile);
483 	}
484 	return (1);
485 }
486 
487 /*
488  * do_tr --
489  *	Perform translation ('y' command) in the pattern space.
490  */
491 static void
492 do_tr(struct s_tr *y)
493 {
494 	SPACE tmp;
495 	char c, *p;
496 	size_t clen, left;
497 	int i;
498 
499 	if (MB_CUR_MAX == 1) {
500 		/*
501 		 * Single-byte encoding: perform in-place translation
502 		 * of the pattern space.
503 		 */
504 		for (p = ps; p < &ps[psl]; p++)
505 			*p = y->bytetab[(u_char)*p];
506 	} else {
507 		/*
508 		 * Multi-byte encoding: perform translation into the
509 		 * translation space, then swap the translation and
510 		 * pattern spaces.
511 		 */
512 		/* Clean translation space. */
513 		YS.len = 0;
514 		for (p = ps, left = psl; left > 0; p += clen, left -= clen) {
515 			if ((c = y->bytetab[(u_char)*p]) != '\0') {
516 				cspace(&YS, &c, 1, APPEND);
517 				clen = 1;
518 				continue;
519 			}
520 			for (i = 0; i < y->nmultis; i++)
521 				if (left >= y->multis[i].fromlen &&
522 				    memcmp(p, y->multis[i].from,
523 				    y->multis[i].fromlen) == 0)
524 					break;
525 			if (i < y->nmultis) {
526 				cspace(&YS, y->multis[i].to,
527 				    y->multis[i].tolen, APPEND);
528 				clen = y->multis[i].fromlen;
529 			} else {
530 				cspace(&YS, p, 1, APPEND);
531 				clen = 1;
532 			}
533 		}
534 		/* Swap the translation space and the pattern space. */
535 		tmp = PS;
536 		PS = YS;
537 		psanl = tmp.append_newline;
538 		YS = tmp;
539 		YS.space = YS.back;
540 	}
541 }
542 
543 /*
544  * Flush append requests.  Always called before reading a line,
545  * therefore it also resets the substitution done (sdone) flag.
546  */
547 static void
548 flush_appends(void)
549 {
550 	FILE *f;
551 	int count, i;
552 	char buf[8 * 1024];
553 
554 	for (i = 0; i < appendx; i++)
555 		switch (appends[i].type) {
556 		case AP_STRING:
557 			fwrite(appends[i].s, sizeof(char), appends[i].len,
558 			    outfile);
559 			break;
560 		case AP_FILE:
561 			/*
562 			 * Read files probably shouldn't be cached.  Since
563 			 * it's not an error to read a non-existent file,
564 			 * it's possible that another program is interacting
565 			 * with the sed script through the filesystem.  It
566 			 * would be truly bizarre, but possible.  It's probably
567 			 * not that big a performance win, anyhow.
568 			 */
569 			if ((f = fopen(appends[i].s, "r")) == NULL)
570 				break;
571 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
572 				(void)fwrite(buf, sizeof(char), count, outfile);
573 			(void)fclose(f);
574 			break;
575 		}
576 	if (ferror(outfile))
577 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
578 	appendx = sdone = 0;
579 }
580 
581 static void
582 lputs(char *s, size_t len)
583 {
584 	static const char escapes[] = "\\\a\b\f\r\t\v";
585 	int c, col, width;
586 	const char *p;
587 	struct winsize win;
588 	static int termwidth = -1;
589 	size_t clen, i;
590 	wchar_t wc;
591 	mbstate_t mbs;
592 
593 	if (outfile != stdout)
594 		termwidth = 60;
595 	if (termwidth == -1) {
596 		if ((p = getenv("COLUMNS")) && *p != '\0')
597 			termwidth = atoi(p);
598 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
599 		    win.ws_col > 0)
600 			termwidth = win.ws_col;
601 		else
602 			termwidth = 60;
603 	}
604 	if (termwidth <= 0)
605 		termwidth = 1;
606 
607 	memset(&mbs, 0, sizeof(mbs));
608 	col = 0;
609 	while (len != 0) {
610 		clen = mbrtowc(&wc, s, len, &mbs);
611 		if (clen == 0)
612 			clen = 1;
613 		if (clen == (size_t)-1 || clen == (size_t)-2) {
614 			wc = (unsigned char)*s;
615 			clen = 1;
616 			memset(&mbs, 0, sizeof(mbs));
617 		}
618 		if (wc == '\n') {
619 			if (col + 1 >= termwidth)
620 				fprintf(outfile, "\\\n");
621 			fputc('$', outfile);
622 			fputc('\n', outfile);
623 			col = 0;
624 		} else if (iswprint(wc)) {
625 			width = wcwidth(wc);
626 			if (col + width >= termwidth) {
627 				fprintf(outfile, "\\\n");
628 				col = 0;
629 			}
630 			fwrite(s, 1, clen, outfile);
631 			col += width;
632 		} else if (wc != L'\0' && (c = wctob(wc)) != EOF &&
633 		    (p = strchr(escapes, c)) != NULL) {
634 			if (col + 2 >= termwidth) {
635 				fprintf(outfile, "\\\n");
636 				col = 0;
637 			}
638 			fprintf(outfile, "\\%c", "\\abfrtv"[p - escapes]);
639 			col += 2;
640 		} else {
641 			if (col + 4 * clen >= (unsigned)termwidth) {
642 				fprintf(outfile, "\\\n");
643 				col = 0;
644 			}
645 			for (i = 0; i < clen; i++)
646 				fprintf(outfile, "\\%03o",
647 				    (int)(unsigned char)s[i]);
648 			col += 4 * clen;
649 		}
650 		s += clen;
651 		len -= clen;
652 	}
653 	if (col + 1 >= termwidth)
654 		fprintf(outfile, "\\\n");
655 	(void)fputc('$', outfile);
656 	(void)fputc('\n', outfile);
657 	if (ferror(outfile))
658 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
659 }
660 
661 static int
662 regexec_e(regex_t *preg, const char *string, int eflags, int nomatch,
663 	size_t start, size_t stop)
664 {
665 	int eval;
666 
667 	if (preg == NULL) {
668 		if (defpreg == NULL)
669 			errx(1, "first RE may not be empty");
670 	} else
671 		defpreg = preg;
672 
673 	/* Set anchors */
674 	match[0].rm_so = start;
675 	match[0].rm_eo = stop;
676 
677 	eval = regexec(defpreg, string,
678 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
679 	switch(eval) {
680 	case 0:
681 		return (1);
682 	case REG_NOMATCH:
683 		return (0);
684 	}
685 	errx(1, "RE error: %s", strregerror(eval, defpreg));
686 	/* NOTREACHED */
687 }
688 
689 /*
690  * regsub - perform substitutions after a regexp match
691  * Based on a routine by Henry Spencer
692  */
693 static void
694 regsub(SPACE *sp, char *string, char *src)
695 {
696 	int len, no;
697 	char c, *dst;
698 
699 #define	NEEDSP(reqlen)							\
700 	/* XXX What is the +1 for? */					\
701 	if (sp->len + (reqlen) + 1 >= sp->blen) {			\
702 		sp->blen += (reqlen) + 1024;				\
703 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
704 		    == NULL)						\
705 			err(1, "realloc");				\
706 		dst = sp->space + sp->len;				\
707 	}
708 
709 	dst = sp->space + sp->len;
710 	while ((c = *src++) != '\0') {
711 		if (c == '&')
712 			no = 0;
713 		else if (c == '\\' && isdigit((unsigned char)*src))
714 			no = *src++ - '0';
715 		else
716 			no = -1;
717 		if (no < 0) {		/* Ordinary character. */
718 			if (c == '\\' && (*src == '\\' || *src == '&'))
719 				c = *src++;
720 			NEEDSP(1);
721 			*dst++ = c;
722 			++sp->len;
723 		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
724 			len = match[no].rm_eo - match[no].rm_so;
725 			NEEDSP(len);
726 			memmove(dst, string + match[no].rm_so, len);
727 			dst += len;
728 			sp->len += len;
729 		}
730 	}
731 	NEEDSP(1);
732 	*dst = '\0';
733 }
734 
735 /*
736  * cspace --
737  *	Concatenate space: append the source space to the destination space,
738  *	allocating new space as necessary.
739  */
740 void
741 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
742 {
743 	size_t tlen;
744 
745 	/* Make sure SPACE has enough memory and ramp up quickly. */
746 	tlen = sp->len + len + 1;
747 	if (tlen > sp->blen) {
748 		sp->blen = tlen + 1024;
749 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
750 		    NULL)
751 			err(1, "realloc");
752 	}
753 
754 	if (spflag == REPLACE)
755 		sp->len = 0;
756 
757 	memmove(sp->space + sp->len, p, len);
758 
759 	sp->space[sp->len += len] = '\0';
760 }
761 
762 /*
763  * Close all cached opened files and report any errors
764  */
765 void
766 cfclose(struct s_command *cp, struct s_command *end)
767 {
768 
769 	for (; cp != end; cp = cp->next)
770 		switch(cp->code) {
771 		case 's':
772 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
773 				err(1, "%s", cp->u.s->wfile);
774 			cp->u.s->wfd = -1;
775 			break;
776 		case 'w':
777 			if (cp->u.fd != -1 && close(cp->u.fd))
778 				err(1, "%s", cp->t);
779 			cp->u.fd = -1;
780 			break;
781 		case '{':
782 			cfclose(cp->u.c, cp->next);
783 			break;
784 		}
785 }
786