xref: /freebsd/usr.bin/sed/process.c (revision f1ed5c000c688cf9781b486134baf4ba25415efd)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992 Diomidis Spinellis.
5  * Copyright (c) 1992, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Diomidis Spinellis of Imperial College, University of London.
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 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #ifndef lint
40 static const char sccsid[] = "@(#)process.c	8.6 (Berkeley) 4/20/94";
41 #endif
42 
43 #include <sys/types.h>
44 #include <sys/stat.h>
45 #include <sys/ioctl.h>
46 #include <sys/uio.h>
47 
48 #include <ctype.h>
49 #include <err.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <limits.h>
53 #include <regex.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 #include <wchar.h>
59 #include <wctype.h>
60 
61 #include "defs.h"
62 #include "extern.h"
63 
64 static SPACE HS, PS, SS, YS;
65 #define	pd		PS.deleted
66 #define	ps		PS.space
67 #define	psl		PS.len
68 #define	psanl		PS.append_newline
69 #define	hs		HS.space
70 #define	hsl		HS.len
71 
72 static inline int	 applies(struct s_command *);
73 static void		 do_tr(struct s_tr *);
74 static void		 flush_appends(void);
75 static void		 lputs(char *, size_t);
76 static int		 regexec_e(regex_t *, const char *, int, int, size_t,
77 			     size_t);
78 static void		 regsub(SPACE *, char *, char *);
79 static int		 substitute(struct s_command *);
80 
81 struct s_appends *appends;	/* Array of pointers to strings to append. */
82 static int appendx;		/* Index into appends array. */
83 int appendnum;			/* Size of appends array. */
84 
85 static int lastaddr;		/* Set by applies if last address of a range. */
86 static int sdone;		/* If any substitutes since last line input. */
87 				/* Iov structure for 'w' commands. */
88 static regex_t *defpreg;
89 size_t maxnsub;
90 regmatch_t *match;
91 
92 #define OUT() do {							\
93 	fwrite(ps, 1, psl, outfile);					\
94 	if (psanl) fputc('\n', outfile);				\
95 } while (0)
96 
97 void
98 process(void)
99 {
100 	struct s_command *cp;
101 	SPACE tspace;
102 	size_t oldpsl;
103 	char *p;
104 	int oldpsanl;
105 
106 	p = NULL;
107 	oldpsanl = oldpsl = 0;
108 
109 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
110 		pd = 0;
111 top:
112 		cp = prog;
113 redirect:
114 		while (cp != NULL) {
115 			if (!applies(cp)) {
116 				cp = cp->next;
117 				continue;
118 			}
119 			switch (cp->code) {
120 			case '{':
121 				cp = cp->u.c;
122 				goto redirect;
123 			case 'a':
124 				if (appendx >= appendnum)
125 					if ((appends = realloc(appends,
126 					    sizeof(struct s_appends) *
127 					    (appendnum *= 2))) == NULL)
128 						err(1, "realloc");
129 				appends[appendx].type = AP_STRING;
130 				appends[appendx].s = cp->t;
131 				appends[appendx].len = strlen(cp->t);
132 				appendx++;
133 				break;
134 			case 'b':
135 				cp = cp->u.c;
136 				goto redirect;
137 			case 'c':
138 				pd = 1;
139 				psl = 0;
140 				if (cp->a2 == NULL || lastaddr || lastline())
141 					(void)fprintf(outfile, "%s", cp->t);
142 				break;
143 			case 'd':
144 				pd = 1;
145 				goto new;
146 			case 'D':
147 				if (pd)
148 					goto new;
149 				if (psl == 0 ||
150 				    (p = memchr(ps, '\n', psl)) == NULL) {
151 					pd = 1;
152 					goto new;
153 				} else {
154 					psl -= (p + 1) - ps;
155 					memmove(ps, p + 1, psl);
156 					goto top;
157 				}
158 			case 'g':
159 				cspace(&PS, hs, hsl, REPLACE);
160 				break;
161 			case 'G':
162 				cspace(&PS, "\n", 1, APPEND);
163 				cspace(&PS, hs, hsl, APPEND);
164 				break;
165 			case 'h':
166 				cspace(&HS, ps, psl, REPLACE);
167 				break;
168 			case 'H':
169 				cspace(&HS, "\n", 1, APPEND);
170 				cspace(&HS, ps, psl, APPEND);
171 				break;
172 			case 'i':
173 				(void)fprintf(outfile, "%s", cp->t);
174 				break;
175 			case 'l':
176 				lputs(ps, psl);
177 				break;
178 			case 'n':
179 				if (!nflag && !pd)
180 					OUT();
181 				flush_appends();
182 				if (!mf_fgets(&PS, REPLACE))
183 					exit(0);
184 				pd = 0;
185 				break;
186 			case 'N':
187 				flush_appends();
188 				cspace(&PS, "\n", 1, APPEND);
189 				if (!mf_fgets(&PS, APPEND))
190 					exit(0);
191 				break;
192 			case 'p':
193 				if (pd)
194 					break;
195 				OUT();
196 				break;
197 			case 'P':
198 				if (pd)
199 					break;
200 				if ((p = memchr(ps, '\n', psl)) != NULL) {
201 					oldpsl = psl;
202 					oldpsanl = psanl;
203 					psl = p - ps;
204 					psanl = 1;
205 				}
206 				OUT();
207 				if (p != NULL) {
208 					psl = oldpsl;
209 					psanl = oldpsanl;
210 				}
211 				break;
212 			case 'q':
213 				if (!nflag && !pd)
214 					OUT();
215 				flush_appends();
216 				exit(0);
217 			case 'r':
218 				if (appendx >= appendnum)
219 					if ((appends = realloc(appends,
220 					    sizeof(struct s_appends) *
221 					    (appendnum *= 2))) == NULL)
222 						err(1, "realloc");
223 				appends[appendx].type = AP_FILE;
224 				appends[appendx].s = cp->t;
225 				appends[appendx].len = strlen(cp->t);
226 				appendx++;
227 				break;
228 			case 's':
229 				sdone |= substitute(cp);
230 				break;
231 			case 't':
232 				if (sdone) {
233 					sdone = 0;
234 					cp = cp->u.c;
235 					goto redirect;
236 				}
237 				break;
238 			case 'w':
239 				if (pd)
240 					break;
241 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
242 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
243 				    DEFFILEMODE)) == -1)
244 					err(1, "%s", cp->t);
245 				if (write(cp->u.fd, ps, psl) != (ssize_t)psl ||
246 				    write(cp->u.fd, "\n", 1) != 1)
247 					err(1, "%s", cp->t);
248 				break;
249 			case 'x':
250 				/*
251 				 * If the hold space is null, make it empty
252 				 * but not null.  Otherwise the pattern space
253 				 * will become null after the swap, which is
254 				 * an abnormal condition.
255 				 */
256 				if (hs == NULL)
257 					cspace(&HS, "", 0, REPLACE);
258 				tspace = PS;
259 				PS = HS;
260 				psanl = tspace.append_newline;
261 				HS = tspace;
262 				break;
263 			case 'y':
264 				if (pd || psl == 0)
265 					break;
266 				do_tr(cp->u.y);
267 				break;
268 			case ':':
269 			case '}':
270 				break;
271 			case '=':
272 				(void)fprintf(outfile, "%lu\n", linenum);
273 			}
274 			cp = cp->next;
275 		} /* for all cp */
276 
277 new:		if (!nflag && !pd)
278 			OUT();
279 		flush_appends();
280 	} /* for all lines */
281 }
282 
283 /*
284  * TRUE if the address passed matches the current program state
285  * (lastline, linenumber, ps).
286  */
287 #define	MATCH(a)							\
288 	((a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, 0, psl) :	\
289 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline())
290 
291 /*
292  * Return TRUE if the command applies to the current line.  Sets the start
293  * line for process ranges.  Interprets the non-select (``!'') flag.
294  */
295 static inline int
296 applies(struct s_command *cp)
297 {
298 	int r;
299 
300 	lastaddr = 0;
301 	if (cp->a1 == NULL && cp->a2 == NULL)
302 		r = 1;
303 	else if (cp->a2)
304 		if (cp->startline > 0) {
305                         switch (cp->a2->type) {
306                         case AT_RELLINE:
307                                 if (linenum - cp->startline <= cp->a2->u.l)
308                                         r = 1;
309                                 else {
310 				        cp->startline = 0;
311 				        r = 0;
312                                 }
313                                 break;
314                         default:
315                                 if (MATCH(cp->a2)) {
316                                         cp->startline = 0;
317                                         lastaddr = 1;
318                                         r = 1;
319                                 } else if (cp->a2->type == AT_LINE &&
320                                             linenum > cp->a2->u.l) {
321                                         /*
322                                          * We missed the 2nd address due to a
323                                          * branch, so just close the range and
324                                          * return false.
325                                          */
326                                         cp->startline = 0;
327                                         r = 0;
328                                 } else
329                                         r = 1;
330                         }
331 		} else if (cp->a1 && MATCH(cp->a1)) {
332 			/*
333 			 * If the second address is a number less than or
334 			 * equal to the line number first selected, only
335 			 * one line shall be selected.
336 			 *	-- POSIX 1003.2
337 			 * Likewise if the relative second line address is zero.
338 			 */
339 			if ((cp->a2->type == AT_LINE &&
340 			    linenum >= cp->a2->u.l) ||
341 			    (cp->a2->type == AT_RELLINE && cp->a2->u.l == 0))
342 				lastaddr = 1;
343 			else {
344 				cp->startline = linenum;
345 			}
346 			r = 1;
347 		} else
348 			r = 0;
349 	else
350 		r = MATCH(cp->a1);
351 	return (cp->nonsel ? ! r : r);
352 }
353 
354 /*
355  * Reset the sed processor to its initial state.
356  */
357 void
358 resetstate(void)
359 {
360 	struct s_command *cp;
361 
362 	/*
363 	 * Reset all in-range markers.
364 	 */
365 	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
366 		if (cp->a2)
367 			cp->startline = 0;
368 
369 	/*
370 	 * Clear out the hold space.
371 	 */
372 	cspace(&HS, "", 0, REPLACE);
373 }
374 
375 /*
376  * substitute --
377  *	Do substitutions in the pattern space.  Currently, we build a
378  *	copy of the new pattern space in the substitute space structure
379  *	and then swap them.
380  */
381 static int
382 substitute(struct s_command *cp)
383 {
384 	SPACE tspace;
385 	regex_t *re;
386 	regoff_t slen;
387 	int lastempty, n;
388 	size_t le = 0;
389 	char *s;
390 
391 	s = ps;
392 	re = cp->u.s->re;
393 	if (re == NULL) {
394 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
395 			linenum = cp->u.s->linenum;
396 			errx(1, "%lu: %s: \\%u not defined in the RE",
397 					linenum, fname, cp->u.s->maxbref);
398 		}
399 	}
400 	if (!regexec_e(re, ps, 0, 0, 0, psl))
401 		return (0);
402 
403 	SS.len = 0;				/* Clean substitute space. */
404 	slen = psl;
405 	n = cp->u.s->n;
406 	lastempty = 1;
407 
408 	do {
409 		/* Copy the leading retained string. */
410 		if (n <= 1 && (match[0].rm_so > le))
411 			cspace(&SS, s, match[0].rm_so - le, APPEND);
412 
413 		/* Skip zero-length matches right after other matches. */
414 		if (lastempty || (match[0].rm_so - le) ||
415 		    match[0].rm_so != match[0].rm_eo) {
416 			if (n <= 1) {
417 				/* Want this match: append replacement. */
418 				regsub(&SS, ps, cp->u.s->new);
419 				if (n == 1)
420 					n = -1;
421 			} else {
422 				/* Want a later match: append original. */
423 				if (match[0].rm_eo - le)
424 					cspace(&SS, s, match[0].rm_eo - le,
425 					    APPEND);
426 				n--;
427 			}
428 		}
429 
430 		/* Move past this match. */
431 		s = ps + match[0].rm_eo;
432 		slen = psl - match[0].rm_eo;
433 		le = match[0].rm_eo;
434 
435 		/*
436 		 * After a zero-length match, advance one byte,
437 		 * and at the end of the line, terminate.
438 		 */
439 		if (match[0].rm_so == match[0].rm_eo) {
440 			if (*s == '\0' || *s == '\n')
441 				slen = -1;
442 			else
443 				slen--;
444 			if (*s != '\0') {
445 			 	cspace(&SS, s++, 1, APPEND);
446 				le++;
447 			}
448 			lastempty = 1;
449 		} else
450 			lastempty = 0;
451 
452 	} while (n >= 0 && slen >= 0 &&
453 	    regexec_e(re, ps, REG_NOTBOL, 0, le, psl));
454 
455 	/* Did not find the requested number of matches. */
456 	if (n > 0)
457 		return (0);
458 
459 	/* Copy the trailing retained string. */
460 	if (slen > 0)
461 		cspace(&SS, s, slen, APPEND);
462 
463 	/*
464 	 * Swap the substitute space and the pattern space, and make sure
465 	 * that any leftover pointers into stdio memory get lost.
466 	 */
467 	tspace = PS;
468 	PS = SS;
469 	psanl = tspace.append_newline;
470 	SS = tspace;
471 	SS.space = SS.back;
472 
473 	/* Handle the 'p' flag. */
474 	if (cp->u.s->p)
475 		OUT();
476 
477 	/* Handle the 'w' flag. */
478 	if (cp->u.s->wfile && !pd) {
479 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
480 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
481 			err(1, "%s", cp->u.s->wfile);
482 		if (write(cp->u.s->wfd, ps, psl) != (ssize_t)psl ||
483 		    write(cp->u.s->wfd, "\n", 1) != 1)
484 			err(1, "%s", cp->u.s->wfile);
485 	}
486 	return (1);
487 }
488 
489 /*
490  * do_tr --
491  *	Perform translation ('y' command) in the pattern space.
492  */
493 static void
494 do_tr(struct s_tr *y)
495 {
496 	SPACE tmp;
497 	char c, *p;
498 	size_t clen, left;
499 	int i;
500 
501 	if (MB_CUR_MAX == 1) {
502 		/*
503 		 * Single-byte encoding: perform in-place translation
504 		 * of the pattern space.
505 		 */
506 		for (p = ps; p < &ps[psl]; p++)
507 			*p = y->bytetab[(u_char)*p];
508 	} else {
509 		/*
510 		 * Multi-byte encoding: perform translation into the
511 		 * translation space, then swap the translation and
512 		 * pattern spaces.
513 		 */
514 		/* Clean translation space. */
515 		YS.len = 0;
516 		for (p = ps, left = psl; left > 0; p += clen, left -= clen) {
517 			if ((c = y->bytetab[(u_char)*p]) != '\0') {
518 				cspace(&YS, &c, 1, APPEND);
519 				clen = 1;
520 				continue;
521 			}
522 			for (i = 0; i < y->nmultis; i++)
523 				if (left >= y->multis[i].fromlen &&
524 				    memcmp(p, y->multis[i].from,
525 				    y->multis[i].fromlen) == 0)
526 					break;
527 			if (i < y->nmultis) {
528 				cspace(&YS, y->multis[i].to,
529 				    y->multis[i].tolen, APPEND);
530 				clen = y->multis[i].fromlen;
531 			} else {
532 				cspace(&YS, p, 1, APPEND);
533 				clen = 1;
534 			}
535 		}
536 		/* Swap the translation space and the pattern space. */
537 		tmp = PS;
538 		PS = YS;
539 		psanl = tmp.append_newline;
540 		YS = tmp;
541 		YS.space = YS.back;
542 	}
543 }
544 
545 /*
546  * Flush append requests.  Always called before reading a line,
547  * therefore it also resets the substitution done (sdone) flag.
548  */
549 static void
550 flush_appends(void)
551 {
552 	FILE *f;
553 	int count, i;
554 	char buf[8 * 1024];
555 
556 	for (i = 0; i < appendx; i++)
557 		switch (appends[i].type) {
558 		case AP_STRING:
559 			fwrite(appends[i].s, sizeof(char), appends[i].len,
560 			    outfile);
561 			break;
562 		case AP_FILE:
563 			/*
564 			 * Read files probably shouldn't be cached.  Since
565 			 * it's not an error to read a non-existent file,
566 			 * it's possible that another program is interacting
567 			 * with the sed script through the filesystem.  It
568 			 * would be truly bizarre, but possible.  It's probably
569 			 * not that big a performance win, anyhow.
570 			 */
571 			if ((f = fopen(appends[i].s, "r")) == NULL)
572 				break;
573 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
574 				(void)fwrite(buf, sizeof(char), count, outfile);
575 			(void)fclose(f);
576 			break;
577 		}
578 	if (ferror(outfile))
579 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
580 	appendx = sdone = 0;
581 }
582 
583 static void
584 lputs(char *s, size_t len)
585 {
586 	static const char escapes[] = "\\\a\b\f\r\t\v";
587 	int c, col, width;
588 	const char *p;
589 	struct winsize win;
590 	static int termwidth = -1;
591 	size_t clen, i;
592 	wchar_t wc;
593 	mbstate_t mbs;
594 
595 	if (outfile != stdout)
596 		termwidth = 60;
597 	if (termwidth == -1) {
598 		if ((p = getenv("COLUMNS")) && *p != '\0')
599 			termwidth = atoi(p);
600 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
601 		    win.ws_col > 0)
602 			termwidth = win.ws_col;
603 		else
604 			termwidth = 60;
605 	}
606 	if (termwidth <= 0)
607 		termwidth = 1;
608 
609 	memset(&mbs, 0, sizeof(mbs));
610 	col = 0;
611 	while (len != 0) {
612 		clen = mbrtowc(&wc, s, len, &mbs);
613 		if (clen == 0)
614 			clen = 1;
615 		if (clen == (size_t)-1 || clen == (size_t)-2) {
616 			wc = (unsigned char)*s;
617 			clen = 1;
618 			memset(&mbs, 0, sizeof(mbs));
619 		}
620 		if (wc == '\n') {
621 			if (col + 1 >= termwidth)
622 				fprintf(outfile, "\\\n");
623 			fputc('$', outfile);
624 			fputc('\n', outfile);
625 			col = 0;
626 		} else if (iswprint(wc)) {
627 			width = wcwidth(wc);
628 			if (col + width >= termwidth) {
629 				fprintf(outfile, "\\\n");
630 				col = 0;
631 			}
632 			fwrite(s, 1, clen, outfile);
633 			col += width;
634 		} else if (wc != L'\0' && (c = wctob(wc)) != EOF &&
635 		    (p = strchr(escapes, c)) != NULL) {
636 			if (col + 2 >= termwidth) {
637 				fprintf(outfile, "\\\n");
638 				col = 0;
639 			}
640 			fprintf(outfile, "\\%c", "\\abfrtv"[p - escapes]);
641 			col += 2;
642 		} else {
643 			if (col + 4 * clen >= (unsigned)termwidth) {
644 				fprintf(outfile, "\\\n");
645 				col = 0;
646 			}
647 			for (i = 0; i < clen; i++)
648 				fprintf(outfile, "\\%03o",
649 				    (int)(unsigned char)s[i]);
650 			col += 4 * clen;
651 		}
652 		s += clen;
653 		len -= clen;
654 	}
655 	if (col + 1 >= termwidth)
656 		fprintf(outfile, "\\\n");
657 	(void)fputc('$', outfile);
658 	(void)fputc('\n', outfile);
659 	if (ferror(outfile))
660 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
661 }
662 
663 static int
664 regexec_e(regex_t *preg, const char *string, int eflags, int nomatch,
665 	size_t start, size_t stop)
666 {
667 	int eval;
668 
669 	if (preg == NULL) {
670 		if (defpreg == NULL)
671 			errx(1, "first RE may not be empty");
672 	} else
673 		defpreg = preg;
674 
675 	/* Set anchors */
676 	match[0].rm_so = start;
677 	match[0].rm_eo = stop;
678 
679 	eval = regexec(defpreg, string,
680 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
681 	switch(eval) {
682 	case 0:
683 		return (1);
684 	case REG_NOMATCH:
685 		return (0);
686 	}
687 	errx(1, "RE error: %s", strregerror(eval, defpreg));
688 	/* NOTREACHED */
689 }
690 
691 /*
692  * regsub - perform substitutions after a regexp match
693  * Based on a routine by Henry Spencer
694  */
695 static void
696 regsub(SPACE *sp, char *string, char *src)
697 {
698 	int len, no;
699 	char c, *dst;
700 
701 #define	NEEDSP(reqlen)							\
702 	/* XXX What is the +1 for? */					\
703 	if (sp->len + (reqlen) + 1 >= sp->blen) {			\
704 		sp->blen += (reqlen) + 1024;				\
705 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
706 		    == NULL)						\
707 			err(1, "realloc");				\
708 		dst = sp->space + sp->len;				\
709 	}
710 
711 	dst = sp->space + sp->len;
712 	while ((c = *src++) != '\0') {
713 		if (c == '&')
714 			no = 0;
715 		else if (c == '\\' && isdigit((unsigned char)*src))
716 			no = *src++ - '0';
717 		else
718 			no = -1;
719 		if (no < 0) {		/* Ordinary character. */
720 			if (c == '\\' && (*src == '\\' || *src == '&'))
721 				c = *src++;
722 			NEEDSP(1);
723 			*dst++ = c;
724 			++sp->len;
725 		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
726 			len = match[no].rm_eo - match[no].rm_so;
727 			NEEDSP(len);
728 			memmove(dst, string + match[no].rm_so, len);
729 			dst += len;
730 			sp->len += len;
731 		}
732 	}
733 	NEEDSP(1);
734 	*dst = '\0';
735 }
736 
737 /*
738  * cspace --
739  *	Concatenate space: append the source space to the destination space,
740  *	allocating new space as necessary.
741  */
742 void
743 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
744 {
745 	size_t tlen;
746 
747 	/* Make sure SPACE has enough memory and ramp up quickly. */
748 	tlen = sp->len + len + 1;
749 	if (tlen > sp->blen) {
750 		sp->blen = tlen + 1024;
751 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
752 		    NULL)
753 			err(1, "realloc");
754 	}
755 
756 	if (spflag == REPLACE)
757 		sp->len = 0;
758 
759 	memmove(sp->space + sp->len, p, len);
760 
761 	sp->space[sp->len += len] = '\0';
762 }
763 
764 /*
765  * Close all cached opened files and report any errors
766  */
767 void
768 cfclose(struct s_command *cp, struct s_command *end)
769 {
770 
771 	for (; cp != end; cp = cp->next)
772 		switch(cp->code) {
773 		case 's':
774 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
775 				err(1, "%s", cp->u.s->wfile);
776 			cp->u.s->wfd = -1;
777 			break;
778 		case 'w':
779 			if (cp->u.fd != -1 && close(cp->u.fd))
780 				err(1, "%s", cp->t);
781 			cp->u.fd = -1;
782 			break;
783 		case '{':
784 			cfclose(cp->u.c, cp->next);
785 			break;
786 		}
787 }
788