xref: /freebsd/usr.bin/sed/process.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
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  * 4. 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	hs		HS.space
67 #define	hsl		HS.len
68 
69 static __inline int	 applies(struct s_command *);
70 static void		 do_tr(struct s_tr *);
71 static void		 flush_appends(void);
72 static void		 lputs(char *, size_t);
73 static __inline int	 regexec_e(regex_t *, const char *, int, int, size_t);
74 static void		 regsub(SPACE *, char *, char *);
75 static int		 substitute(struct s_command *);
76 
77 struct s_appends *appends;	/* Array of pointers to strings to append. */
78 static int appendx;		/* Index into appends array. */
79 int appendnum;			/* Size of appends array. */
80 
81 static int lastaddr;		/* Set by applies if last address of a range. */
82 static int sdone;		/* If any substitutes since last line input. */
83 				/* Iov structure for 'w' commands. */
84 static regex_t *defpreg;
85 size_t maxnsub;
86 regmatch_t *match;
87 
88 #define OUT() do {fwrite(ps, 1, psl, outfile); fputc('\n', outfile);} while (0)
89 
90 void
91 process(void)
92 {
93 	struct s_command *cp;
94 	SPACE tspace;
95 	size_t oldpsl = 0;
96 	char *p;
97 
98 	p = NULL;
99 
100 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
101 		pd = 0;
102 top:
103 		cp = prog;
104 redirect:
105 		while (cp != NULL) {
106 			if (!applies(cp)) {
107 				cp = cp->next;
108 				continue;
109 			}
110 			switch (cp->code) {
111 			case '{':
112 				cp = cp->u.c;
113 				goto redirect;
114 			case 'a':
115 				if (appendx >= appendnum)
116 					if ((appends = realloc(appends,
117 					    sizeof(struct s_appends) *
118 					    (appendnum *= 2))) == NULL)
119 						err(1, "realloc");
120 				appends[appendx].type = AP_STRING;
121 				appends[appendx].s = cp->t;
122 				appends[appendx].len = strlen(cp->t);
123 				appendx++;
124 				break;
125 			case 'b':
126 				cp = cp->u.c;
127 				goto redirect;
128 			case 'c':
129 				pd = 1;
130 				psl = 0;
131 				if (cp->a2 == NULL || lastaddr || lastline())
132 					(void)fprintf(outfile, "%s", cp->t);
133 				break;
134 			case 'd':
135 				pd = 1;
136 				goto new;
137 			case 'D':
138 				if (pd)
139 					goto new;
140 				if (psl == 0 ||
141 				    (p = memchr(ps, '\n', psl)) == NULL) {
142 					pd = 1;
143 					goto new;
144 				} else {
145 					psl -= (p + 1) - ps;
146 					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 = p - 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 			case 'r':
205 				if (appendx >= appendnum)
206 					if ((appends = realloc(appends,
207 					    sizeof(struct s_appends) *
208 					    (appendnum *= 2))) == NULL)
209 						err(1, "realloc");
210 				appends[appendx].type = AP_FILE;
211 				appends[appendx].s = cp->t;
212 				appends[appendx].len = strlen(cp->t);
213 				appendx++;
214 				break;
215 			case 's':
216 				sdone |= substitute(cp);
217 				break;
218 			case 't':
219 				if (sdone) {
220 					sdone = 0;
221 					cp = cp->u.c;
222 					goto redirect;
223 				}
224 				break;
225 			case 'w':
226 				if (pd)
227 					break;
228 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
229 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
230 				    DEFFILEMODE)) == -1)
231 					err(1, "%s", cp->t);
232 				if (write(cp->u.fd, ps, psl) != psl ||
233 				    write(cp->u.fd, "\n", 1) != 1)
234 					err(1, "%s", cp->t);
235 				break;
236 			case 'x':
237 				/*
238 				 * If the hold space is null, make it empty
239 				 * but not null.  Otherwise the pattern space
240 				 * will become null after the swap, which is
241 				 * an abnormal condition.
242 				 */
243 				if (hs == NULL)
244 					cspace(&HS, "", 0, REPLACE);
245 				tspace = PS;
246 				PS = HS;
247 				HS = tspace;
248 				break;
249 			case 'y':
250 				if (pd || psl == 0)
251 					break;
252 				do_tr(cp->u.y);
253 				break;
254 			case ':':
255 			case '}':
256 				break;
257 			case '=':
258 				(void)fprintf(outfile, "%lu\n", linenum);
259 			}
260 			cp = cp->next;
261 		} /* for all cp */
262 
263 new:		if (!nflag && !pd)
264 			OUT();
265 		flush_appends();
266 	} /* for all lines */
267 }
268 
269 /*
270  * TRUE if the address passed matches the current program state
271  * (lastline, linenumber, ps).
272  */
273 #define	MATCH(a)							\
274 	((a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
275 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline())
276 
277 /*
278  * Return TRUE if the command applies to the current line.  Sets the inrange
279  * flag to process ranges.  Interprets the non-select (``!'') flag.
280  */
281 static __inline int
282 applies(struct s_command *cp)
283 {
284 	int r;
285 
286 	lastaddr = 0;
287 	if (cp->a1 == NULL && cp->a2 == NULL)
288 		r = 1;
289 	else if (cp->a2)
290 		if (cp->inrange) {
291 			if (MATCH(cp->a2)) {
292 				cp->inrange = 0;
293 				lastaddr = 1;
294 				r = 1;
295 			} else if (cp->a2->type == AT_LINE &&
296 				   linenum > cp->a2->u.l) {
297 				/*
298 				 * We missed the 2nd address due to a branch,
299 				 * so just close the range and return false.
300 				 */
301 				cp->inrange = 0;
302 				r = 0;
303 			} else
304 				r = 1;
305 		} else if (MATCH(cp->a1)) {
306 			/*
307 			 * If the second address is a number less than or
308 			 * equal to the line number first selected, only
309 			 * one line shall be selected.
310 			 *	-- POSIX 1003.2
311 			 */
312 			if (cp->a2->type == AT_LINE &&
313 			    linenum >= cp->a2->u.l)
314 				lastaddr = 1;
315 			else
316 				cp->inrange = 1;
317 			r = 1;
318 		} else
319 			r = 0;
320 	else
321 		r = MATCH(cp->a1);
322 	return (cp->nonsel ? ! r : r);
323 }
324 
325 /*
326  * Reset the sed processor to its initial state.
327  */
328 void
329 resetstate(void)
330 {
331 	struct s_command *cp;
332 
333 	/*
334 	 * Reset all inrange markers.
335 	 */
336 	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
337 		if (cp->a2)
338 			cp->inrange = 0;
339 
340 	/*
341 	 * Clear out the hold space.
342 	 */
343 	cspace(&HS, "", 0, REPLACE);
344 }
345 
346 /*
347  * substitute --
348  *	Do substitutions in the pattern space.  Currently, we build a
349  *	copy of the new pattern space in the substitute space structure
350  *	and then swap them.
351  */
352 static int
353 substitute(struct s_command *cp)
354 {
355 	SPACE tspace;
356 	regex_t *re;
357 	regoff_t re_off, slen;
358 	int lastempty, n;
359 	char *s;
360 
361 	s = ps;
362 	re = cp->u.s->re;
363 	if (re == NULL) {
364 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
365 			linenum = cp->u.s->linenum;
366 			errx(1, "%lu: %s: \\%d not defined in the RE",
367 					linenum, fname, cp->u.s->maxbref);
368 		}
369 	}
370 	if (!regexec_e(re, s, 0, 0, psl))
371 		return (0);
372 
373 	SS.len = 0;				/* Clean substitute space. */
374 	slen = psl;
375 	n = cp->u.s->n;
376 	lastempty = 1;
377 
378 	switch (n) {
379 	case 0:					/* Global */
380 		do {
381 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
382 				/* Locate start of replaced string. */
383 				re_off = match[0].rm_so;
384 				/* Copy leading retained string. */
385 				cspace(&SS, s, re_off, APPEND);
386 				/* Add in regular expression. */
387 				regsub(&SS, s, cp->u.s->new);
388 			}
389 
390 			/* Move past this match. */
391 			if (match[0].rm_so != match[0].rm_eo) {
392 				s += match[0].rm_eo;
393 				slen -= match[0].rm_eo;
394 				lastempty = 0;
395 			} else {
396 				if (match[0].rm_so < slen)
397 					cspace(&SS, s + match[0].rm_so, 1,
398 					    APPEND);
399 				s += match[0].rm_so + 1;
400 				slen -= match[0].rm_so + 1;
401 				lastempty = 1;
402 			}
403 		} while (slen >= 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
404 		/* Copy trailing retained string. */
405 		if (slen > 0)
406 			cspace(&SS, s, slen, APPEND);
407 		break;
408 	default:				/* Nth occurrence */
409 		while (--n) {
410 			if (match[0].rm_eo == match[0].rm_so)
411 				match[0].rm_eo = match[0].rm_so + 1;
412 			s += match[0].rm_eo;
413 			slen -= match[0].rm_eo;
414 			if (slen < 0)
415 				return (0);
416 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
417 				return (0);
418 		}
419 		/* FALLTHROUGH */
420 	case 1:					/* 1st occurrence */
421 		/* Locate start of replaced string. */
422 		re_off = match[0].rm_so + (s - ps);
423 		/* Copy leading retained string. */
424 		cspace(&SS, ps, re_off, APPEND);
425 		/* Add in regular expression. */
426 		regsub(&SS, s, cp->u.s->new);
427 		/* Copy trailing retained string. */
428 		s += match[0].rm_eo;
429 		slen -= match[0].rm_eo;
430 		cspace(&SS, s, slen, APPEND);
431 		break;
432 	}
433 
434 	/*
435 	 * Swap the substitute space and the pattern space, and make sure
436 	 * that any leftover pointers into stdio memory get lost.
437 	 */
438 	tspace = PS;
439 	PS = SS;
440 	SS = tspace;
441 	SS.space = SS.back;
442 
443 	/* Handle the 'p' flag. */
444 	if (cp->u.s->p)
445 		OUT();
446 
447 	/* Handle the 'w' flag. */
448 	if (cp->u.s->wfile && !pd) {
449 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
450 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
451 			err(1, "%s", cp->u.s->wfile);
452 		if (write(cp->u.s->wfd, ps, psl) != psl ||
453 		    write(cp->u.s->wfd, "\n", 1) != 1)
454 			err(1, "%s", cp->u.s->wfile);
455 	}
456 	return (1);
457 }
458 
459 /*
460  * do_tr --
461  *	Perform translation ('y' command) in the pattern space.
462  */
463 static void
464 do_tr(struct s_tr *y)
465 {
466 	SPACE tmp;
467 	char c, *p;
468 	size_t clen, left;
469 	int i;
470 
471 	if (MB_CUR_MAX == 1) {
472 		/*
473 		 * Single-byte encoding: perform in-place translation
474 		 * of the pattern space.
475 		 */
476 		for (p = ps; p < &ps[psl]; p++)
477 			*p = y->bytetab[(u_char)*p];
478 	} else {
479 		/*
480 		 * Multi-byte encoding: perform translation into the
481 		 * translation space, then swap the translation and
482 		 * pattern spaces.
483 		 */
484 		/* Clean translation space. */
485 		YS.len = 0;
486 		for (p = ps, left = psl; left > 0; p += clen, left -= clen) {
487 			if ((c = y->bytetab[(u_char)*p]) != '\0') {
488 				cspace(&YS, &c, 1, APPEND);
489 				clen = 1;
490 				continue;
491 			}
492 			for (i = 0; i < y->nmultis; i++)
493 				if (left >= y->multis[i].fromlen &&
494 				    memcmp(p, y->multis[i].from,
495 				    y->multis[i].fromlen) == 0)
496 					break;
497 			if (i < y->nmultis) {
498 				cspace(&YS, y->multis[i].to,
499 				    y->multis[i].tolen, APPEND);
500 				clen = y->multis[i].fromlen;
501 			} else {
502 				cspace(&YS, p, 1, APPEND);
503 				clen = 1;
504 			}
505 		}
506 		/* Swap the translation space and the pattern space. */
507 		tmp = PS;
508 		PS = YS;
509 		YS = tmp;
510 		YS.space = YS.back;
511 	}
512 }
513 
514 /*
515  * Flush append requests.  Always called before reading a line,
516  * therefore it also resets the substitution done (sdone) flag.
517  */
518 static void
519 flush_appends(void)
520 {
521 	FILE *f;
522 	int count, i;
523 	char buf[8 * 1024];
524 
525 	for (i = 0; i < appendx; i++)
526 		switch (appends[i].type) {
527 		case AP_STRING:
528 			fwrite(appends[i].s, sizeof(char), appends[i].len,
529 			    outfile);
530 			break;
531 		case AP_FILE:
532 			/*
533 			 * Read files probably shouldn't be cached.  Since
534 			 * it's not an error to read a non-existent file,
535 			 * it's possible that another program is interacting
536 			 * with the sed script through the filesystem.  It
537 			 * would be truly bizarre, but possible.  It's probably
538 			 * not that big a performance win, anyhow.
539 			 */
540 			if ((f = fopen(appends[i].s, "r")) == NULL)
541 				break;
542 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
543 				(void)fwrite(buf, sizeof(char), count, outfile);
544 			(void)fclose(f);
545 			break;
546 		}
547 	if (ferror(outfile))
548 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
549 	appendx = sdone = 0;
550 }
551 
552 static void
553 lputs(char *s, size_t len)
554 {
555 	static const char escapes[] = "\\\a\b\f\r\t\v";
556 	int c, col, width;
557 	char *p;
558 	struct winsize win;
559 	static int termwidth = -1;
560 	size_t clen, i;
561 	wchar_t wc;
562 	mbstate_t mbs;
563 
564 	if (outfile != stdout)
565 		termwidth = 60;
566 	if (termwidth == -1) {
567 		if ((p = getenv("COLUMNS")) && *p != '\0')
568 			termwidth = atoi(p);
569 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
570 		    win.ws_col > 0)
571 			termwidth = win.ws_col;
572 		else
573 			termwidth = 60;
574 	}
575 
576 	memset(&mbs, 0, sizeof(mbs));
577 	col = 0;
578 	while (len != 0) {
579 		clen = mbrtowc(&wc, s, len, &mbs);
580 		if (clen == 0)
581 			clen = 1;
582 		if (clen == (size_t)-1 || clen == (size_t)-2) {
583 			wc = (unsigned char)*s;
584 			clen = 1;
585 			memset(&mbs, 0, sizeof(mbs));
586 		}
587 		if (wc == '\n') {
588 			if (col + 1 >= termwidth)
589 				fprintf(outfile, "\\\n");
590 			fputc('$', outfile);
591 			fputc('\n', outfile);
592 			col = 0;
593 		} else if (iswprint(wc)) {
594 			width = wcwidth(wc);
595 			if (col + width >= termwidth) {
596 				fprintf(outfile, "\\\n");
597 				col = 0;
598 			}
599 			fwrite(s, 1, clen, outfile);
600 			col += width;
601 		} else if (wc != L'\0' && (c = wctob(wc)) != EOF &&
602 		    (p = strchr(escapes, c)) != NULL) {
603 			if (col + 2 >= termwidth) {
604 				fprintf(outfile, "\\\n");
605 				col = 0;
606 			}
607 			fprintf(outfile, "\\%c", "\\abfrtv"[p - escapes]);
608 			col += 2;
609 		} else {
610 			if (col + 4 * clen >= termwidth) {
611 				fprintf(outfile, "\\\n");
612 				col = 0;
613 			}
614 			for (i = 0; i < clen; i++)
615 				fprintf(outfile, "\\%03o",
616 				    (int)(unsigned char)s[i]);
617 			col += 4 * clen;
618 		}
619 		s += clen;
620 		len -= clen;
621 	}
622 	if (col + 1 >= termwidth)
623 		fprintf(outfile, "\\\n");
624 	(void)fputc('$', outfile);
625 	(void)fputc('\n', outfile);
626 	if (ferror(outfile))
627 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
628 }
629 
630 static __inline int
631 regexec_e(regex_t *preg, const char *string, int eflags, int nomatch,
632 	size_t slen)
633 {
634 	int eval;
635 
636 	if (preg == NULL) {
637 		if (defpreg == NULL)
638 			errx(1, "first RE may not be empty");
639 	} else
640 		defpreg = preg;
641 
642 	/* Set anchors */
643 	match[0].rm_so = 0;
644 	match[0].rm_eo = slen;
645 
646 	eval = regexec(defpreg, string,
647 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
648 	switch(eval) {
649 	case 0:
650 		return (1);
651 	case REG_NOMATCH:
652 		return (0);
653 	}
654 	errx(1, "RE error: %s", strregerror(eval, defpreg));
655 	/* NOTREACHED */
656 }
657 
658 /*
659  * regsub - perform substitutions after a regexp match
660  * Based on a routine by Henry Spencer
661  */
662 static void
663 regsub(SPACE *sp, char *string, char *src)
664 {
665 	int len, no;
666 	char c, *dst;
667 
668 #define	NEEDSP(reqlen)							\
669 	/* XXX What is the +1 for? */					\
670 	if (sp->len + (reqlen) + 1 >= sp->blen) {			\
671 		sp->blen += (reqlen) + 1024;				\
672 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
673 		    == NULL)						\
674 			err(1, "realloc");				\
675 		dst = sp->space + sp->len;				\
676 	}
677 
678 	dst = sp->space + sp->len;
679 	while ((c = *src++) != '\0') {
680 		if (c == '&')
681 			no = 0;
682 		else if (c == '\\' && isdigit((unsigned char)*src))
683 			no = *src++ - '0';
684 		else
685 			no = -1;
686 		if (no < 0) {		/* Ordinary character. */
687 			if (c == '\\' && (*src == '\\' || *src == '&'))
688 				c = *src++;
689 			NEEDSP(1);
690 			*dst++ = c;
691 			++sp->len;
692 		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
693 			len = match[no].rm_eo - match[no].rm_so;
694 			NEEDSP(len);
695 			memmove(dst, string + match[no].rm_so, len);
696 			dst += len;
697 			sp->len += len;
698 		}
699 	}
700 	NEEDSP(1);
701 	*dst = '\0';
702 }
703 
704 /*
705  * cspace --
706  *	Concatenate space: append the source space to the destination space,
707  *	allocating new space as necessary.
708  */
709 void
710 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
711 {
712 	size_t tlen;
713 
714 	/* Make sure SPACE has enough memory and ramp up quickly. */
715 	tlen = sp->len + len + 1;
716 	if (tlen > sp->blen) {
717 		sp->blen = tlen + 1024;
718 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
719 		    NULL)
720 			err(1, "realloc");
721 	}
722 
723 	if (spflag == REPLACE)
724 		sp->len = 0;
725 
726 	memmove(sp->space + sp->len, p, len);
727 
728 	sp->space[sp->len += len] = '\0';
729 }
730 
731 /*
732  * Close all cached opened files and report any errors
733  */
734 void
735 cfclose(struct s_command *cp, struct s_command *end)
736 {
737 
738 	for (; cp != end; cp = cp->next)
739 		switch(cp->code) {
740 		case 's':
741 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
742 				err(1, "%s", cp->u.s->wfile);
743 			cp->u.s->wfd = -1;
744 			break;
745 		case 'w':
746 			if (cp->u.fd != -1 && close(cp->u.fd))
747 				err(1, "%s", cp->t);
748 			cp->u.fd = -1;
749 			break;
750 		case '{':
751 			cfclose(cp->u.c, cp->next);
752 			break;
753 		}
754 }
755