xref: /dragonfly/usr.bin/sed/process.c (revision 8a7bdfea)
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  * @(#)process.c	8.6 (Berkeley) 4/20/94
34  * $FreeBSD: src/usr.bin/sed/process.c,v 1.49 2008/02/09 09:12:02 dwmalone Exp $
35  * $DragonFly: src/usr.bin/sed/process.c,v 1.6 2008/04/08 13:23:38 swildner Exp $
36  */
37 
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <sys/ioctl.h>
41 #include <sys/uio.h>
42 
43 #include <ctype.h>
44 #include <err.h>
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <limits.h>
48 #include <regex.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <wchar.h>
54 #include <wctype.h>
55 
56 #include "defs.h"
57 #include "extern.h"
58 
59 static SPACE HS, PS, SS, YS;
60 #define	pd		PS.deleted
61 #define	ps		PS.space
62 #define	psl		PS.len
63 #define	hs		HS.space
64 #define	hsl		HS.len
65 
66 static __inline int	 applies(struct s_command *);
67 static void		 do_tr(struct s_tr *);
68 static void		 flush_appends(void);
69 static void		 lputs(char *, size_t);
70 static __inline int	 regexec_e(regex_t *, const char *, int, int, size_t);
71 static void		 regsub(SPACE *, char *, char *);
72 static int		 substitute(struct s_command *);
73 
74 struct s_appends *appends;	/* Array of pointers to strings to append. */
75 static int appendx;		/* Index into appends array. */
76 int appendnum;			/* Size of appends array. */
77 
78 static int lastaddr;		/* Set by applies if last address of a range. */
79 static int sdone;		/* If any substitutes since last line input. */
80 				/* Iov structure for 'w' commands. */
81 static regex_t *defpreg;
82 size_t maxnsub;
83 regmatch_t *match;
84 
85 #define OUT() do {fwrite(ps, 1, psl, outfile); fputc('\n', outfile);} while (0)
86 
87 void
88 process(void)
89 {
90 	struct s_command *cp;
91 	SPACE tspace;
92 	size_t oldpsl = 0;
93 	char *p;
94 
95 	p = NULL;
96 
97 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
98 		pd = 0;
99 top:
100 		cp = prog;
101 redirect:
102 		while (cp != NULL) {
103 			if (!applies(cp)) {
104 				cp = cp->next;
105 				continue;
106 			}
107 			switch (cp->code) {
108 			case '{':
109 				cp = cp->u.c;
110 				goto redirect;
111 			case 'a':
112 				if (appendx >= appendnum)
113 					if ((appends = realloc(appends,
114 					    sizeof(struct s_appends) *
115 					    (appendnum *= 2))) == NULL)
116 						err(1, "realloc");
117 				appends[appendx].type = AP_STRING;
118 				appends[appendx].s = cp->t;
119 				appends[appendx].len = strlen(cp->t);
120 				appendx++;
121 				break;
122 			case 'b':
123 				cp = cp->u.c;
124 				goto redirect;
125 			case 'c':
126 				pd = 1;
127 				psl = 0;
128 				if (cp->a2 == NULL || lastaddr || lastline())
129 					(void)fprintf(outfile, "%s", cp->t);
130 				break;
131 			case 'd':
132 				pd = 1;
133 				goto new;
134 			case 'D':
135 				if (pd)
136 					goto new;
137 				if (psl == 0 ||
138 				    (p = memchr(ps, '\n', psl)) == NULL) {
139 					pd = 1;
140 					goto new;
141 				} else {
142 					psl -= (p + 1) - ps;
143 					memmove(ps, p + 1, psl);
144 					goto top;
145 				}
146 			case 'g':
147 				cspace(&PS, hs, hsl, REPLACE);
148 				break;
149 			case 'G':
150 				cspace(&PS, "\n", 1, APPEND);
151 				cspace(&PS, hs, hsl, APPEND);
152 				break;
153 			case 'h':
154 				cspace(&HS, ps, psl, REPLACE);
155 				break;
156 			case 'H':
157 				cspace(&HS, "\n", 1, APPEND);
158 				cspace(&HS, ps, psl, APPEND);
159 				break;
160 			case 'i':
161 				(void)fprintf(outfile, "%s", cp->t);
162 				break;
163 			case 'l':
164 				lputs(ps, psl);
165 				break;
166 			case 'n':
167 				if (!nflag && !pd)
168 					OUT();
169 				flush_appends();
170 				if (!mf_fgets(&PS, REPLACE))
171 					exit(0);
172 				pd = 0;
173 				break;
174 			case 'N':
175 				flush_appends();
176 				cspace(&PS, "\n", 1, APPEND);
177 				if (!mf_fgets(&PS, APPEND))
178 					exit(0);
179 				break;
180 			case 'p':
181 				if (pd)
182 					break;
183 				OUT();
184 				break;
185 			case 'P':
186 				if (pd)
187 					break;
188 				if ((p = memchr(ps, '\n', psl)) != NULL) {
189 					oldpsl = psl;
190 					psl = p - ps;
191 				}
192 				OUT();
193 				if (p != NULL)
194 					psl = oldpsl;
195 				break;
196 			case 'q':
197 				if (!nflag && !pd)
198 					OUT();
199 				flush_appends();
200 				exit(0);
201 			case 'r':
202 				if (appendx >= appendnum)
203 					if ((appends = realloc(appends,
204 					    sizeof(struct s_appends) *
205 					    (appendnum *= 2))) == NULL)
206 						err(1, "realloc");
207 				appends[appendx].type = AP_FILE;
208 				appends[appendx].s = cp->t;
209 				appends[appendx].len = strlen(cp->t);
210 				appendx++;
211 				break;
212 			case 's':
213 				sdone |= substitute(cp);
214 				break;
215 			case 't':
216 				if (sdone) {
217 					sdone = 0;
218 					cp = cp->u.c;
219 					goto redirect;
220 				}
221 				break;
222 			case 'w':
223 				if (pd)
224 					break;
225 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
226 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
227 				    DEFFILEMODE)) == -1)
228 					err(1, "%s", cp->t);
229 				if (write(cp->u.fd, ps, psl) != (ssize_t)psl ||
230 				    write(cp->u.fd, "\n", 1) != 1)
231 					err(1, "%s", cp->t);
232 				break;
233 			case 'x':
234 				/*
235 				 * If the hold space is null, make it empty
236 				 * but not null.  Otherwise the pattern space
237 				 * will become null after the swap, which is
238 				 * an abnormal condition.
239 				 */
240 				if (hs == NULL)
241 					cspace(&HS, "", 0, REPLACE);
242 				tspace = PS;
243 				PS = HS;
244 				HS = tspace;
245 				break;
246 			case 'y':
247 				if (pd || psl == 0)
248 					break;
249 				do_tr(cp->u.y);
250 				break;
251 			case ':':
252 			case '}':
253 				break;
254 			case '=':
255 				(void)fprintf(outfile, "%lu\n", linenum);
256 			}
257 			cp = cp->next;
258 		} /* for all cp */
259 
260 new:		if (!nflag && !pd)
261 			OUT();
262 		flush_appends();
263 	} /* for all lines */
264 }
265 
266 /*
267  * TRUE if the address passed matches the current program state
268  * (lastline, linenumber, ps).
269  */
270 #define	MATCH(a)							\
271 	((a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
272 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline())
273 
274 /*
275  * Return TRUE if the command applies to the current line.  Sets the inrange
276  * flag to process ranges.  Interprets the non-select (``!'') flag.
277  */
278 static __inline int
279 applies(struct s_command *cp)
280 {
281 	int r;
282 
283 	lastaddr = 0;
284 	if (cp->a1 == NULL && cp->a2 == NULL)
285 		r = 1;
286 	else if (cp->a2)
287 		if (cp->inrange) {
288 			if (MATCH(cp->a2)) {
289 				cp->inrange = 0;
290 				lastaddr = 1;
291 				r = 1;
292 			} else if (cp->a2->type == AT_LINE &&
293 				   linenum > cp->a2->u.l) {
294 				/*
295 				 * We missed the 2nd address due to a branch,
296 				 * so just close the range and return false.
297 				 */
298 				cp->inrange = 0;
299 				r = 0;
300 			} else
301 				r = 1;
302 		} else if (MATCH(cp->a1)) {
303 			/*
304 			 * If the second address is a number less than or
305 			 * equal to the line number first selected, only
306 			 * one line shall be selected.
307 			 *	-- POSIX 1003.2
308 			 */
309 			if (cp->a2->type == AT_LINE &&
310 			    linenum >= cp->a2->u.l)
311 				lastaddr = 1;
312 			else
313 				cp->inrange = 1;
314 			r = 1;
315 		} else
316 			r = 0;
317 	else
318 		r = MATCH(cp->a1);
319 	return (cp->nonsel ? ! r : r);
320 }
321 
322 /*
323  * Reset the sed processor to its initial state.
324  */
325 void
326 resetstate(void)
327 {
328 	struct s_command *cp;
329 
330 	/*
331 	 * Reset all inrange markers.
332 	 */
333 	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
334 		if (cp->a2)
335 			cp->inrange = 0;
336 
337 	/*
338 	 * Clear out the hold space.
339 	 */
340 	cspace(&HS, "", 0, REPLACE);
341 }
342 
343 /*
344  * substitute --
345  *	Do substitutions in the pattern space.  Currently, we build a
346  *	copy of the new pattern space in the substitute space structure
347  *	and then swap them.
348  */
349 static int
350 substitute(struct s_command *cp)
351 {
352 	SPACE tspace;
353 	regex_t *re;
354 	regoff_t re_off, slen;
355 	int lastempty, n;
356 	char *s;
357 
358 	s = ps;
359 	re = cp->u.s->re;
360 	if (re == NULL) {
361 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
362 			linenum = cp->u.s->linenum;
363 			errx(1, "%lu: %s: \\%u not defined in the RE",
364 					linenum, fname, cp->u.s->maxbref);
365 		}
366 	}
367 	if (!regexec_e(re, s, 0, 0, psl))
368 		return (0);
369 
370 	SS.len = 0;				/* Clean substitute space. */
371 	slen = psl;
372 	n = cp->u.s->n;
373 	lastempty = 1;
374 
375 	switch (n) {
376 	case 0:					/* Global */
377 		do {
378 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
379 				/* Locate start of replaced string. */
380 				re_off = match[0].rm_so;
381 				/* Copy leading retained string. */
382 				cspace(&SS, s, re_off, APPEND);
383 				/* Add in regular expression. */
384 				regsub(&SS, s, cp->u.s->new);
385 			}
386 
387 			/* Move past this match. */
388 			if (match[0].rm_so != match[0].rm_eo) {
389 				s += match[0].rm_eo;
390 				slen -= match[0].rm_eo;
391 				lastempty = 0;
392 			} else {
393 				if (match[0].rm_so < slen)
394 					cspace(&SS, s + match[0].rm_so, 1,
395 					    APPEND);
396 				s += match[0].rm_so + 1;
397 				slen -= match[0].rm_so + 1;
398 				lastempty = 1;
399 			}
400 		} while (slen >= 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
401 		/* Copy trailing retained string. */
402 		if (slen > 0)
403 			cspace(&SS, s, slen, APPEND);
404 		break;
405 	default:				/* Nth occurrence */
406 		while (--n) {
407 			if (match[0].rm_eo == match[0].rm_so)
408 				match[0].rm_eo = match[0].rm_so + 1;
409 			s += match[0].rm_eo;
410 			slen -= match[0].rm_eo;
411 			if (slen < 0)
412 				return (0);
413 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
414 				return (0);
415 		}
416 		/* FALLTHROUGH */
417 	case 1:					/* 1st occurrence */
418 		/* Locate start of replaced string. */
419 		re_off = match[0].rm_so + (s - ps);
420 		/* Copy leading retained string. */
421 		cspace(&SS, ps, re_off, APPEND);
422 		/* Add in regular expression. */
423 		regsub(&SS, s, cp->u.s->new);
424 		/* Copy trailing retained string. */
425 		s += match[0].rm_eo;
426 		slen -= match[0].rm_eo;
427 		cspace(&SS, s, slen, APPEND);
428 		break;
429 	}
430 
431 	/*
432 	 * Swap the substitute space and the pattern space, and make sure
433 	 * that any leftover pointers into stdio memory get lost.
434 	 */
435 	tspace = PS;
436 	PS = SS;
437 	SS = tspace;
438 	SS.space = SS.back;
439 
440 	/* Handle the 'p' flag. */
441 	if (cp->u.s->p)
442 		OUT();
443 
444 	/* Handle the 'w' flag. */
445 	if (cp->u.s->wfile && !pd) {
446 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
447 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
448 			err(1, "%s", cp->u.s->wfile);
449 		if (write(cp->u.s->wfd, ps, psl) != (ssize_t)psl ||
450 		    write(cp->u.s->wfd, "\n", 1) != 1)
451 			err(1, "%s", cp->u.s->wfile);
452 	}
453 	return (1);
454 }
455 
456 /*
457  * do_tr --
458  *	Perform translation ('y' command) in the pattern space.
459  */
460 static void
461 do_tr(struct s_tr *y)
462 {
463 	SPACE tmp;
464 	char c, *p;
465 	size_t clen, left;
466 	int i;
467 
468 	if (MB_CUR_MAX == 1) {
469 		/*
470 		 * Single-byte encoding: perform in-place translation
471 		 * of the pattern space.
472 		 */
473 		for (p = ps; p < &ps[psl]; p++)
474 			*p = y->bytetab[(u_char)*p];
475 	} else {
476 		/*
477 		 * Multi-byte encoding: perform translation into the
478 		 * translation space, then swap the translation and
479 		 * pattern spaces.
480 		 */
481 		/* Clean translation space. */
482 		YS.len = 0;
483 		for (p = ps, left = psl; left > 0; p += clen, left -= clen) {
484 			if ((c = y->bytetab[(u_char)*p]) != '\0') {
485 				cspace(&YS, &c, 1, APPEND);
486 				clen = 1;
487 				continue;
488 			}
489 			for (i = 0; i < y->nmultis; i++)
490 				if (left >= y->multis[i].fromlen &&
491 				    memcmp(p, y->multis[i].from,
492 				    y->multis[i].fromlen) == 0)
493 					break;
494 			if (i < y->nmultis) {
495 				cspace(&YS, y->multis[i].to,
496 				    y->multis[i].tolen, APPEND);
497 				clen = y->multis[i].fromlen;
498 			} else {
499 				cspace(&YS, p, 1, APPEND);
500 				clen = 1;
501 			}
502 		}
503 		/* Swap the translation space and the pattern space. */
504 		tmp = PS;
505 		PS = YS;
506 		YS = tmp;
507 		YS.space = YS.back;
508 	}
509 }
510 
511 /*
512  * Flush append requests.  Always called before reading a line,
513  * therefore it also resets the substitution done (sdone) flag.
514  */
515 static void
516 flush_appends(void)
517 {
518 	FILE *f;
519 	int count, i;
520 	char buf[8 * 1024];
521 
522 	for (i = 0; i < appendx; i++)
523 		switch (appends[i].type) {
524 		case AP_STRING:
525 			fwrite(appends[i].s, sizeof(char), appends[i].len,
526 			    outfile);
527 			break;
528 		case AP_FILE:
529 			/*
530 			 * Read files probably shouldn't be cached.  Since
531 			 * it's not an error to read a non-existent file,
532 			 * it's possible that another program is interacting
533 			 * with the sed script through the filesystem.  It
534 			 * would be truly bizarre, but possible.  It's probably
535 			 * not that big a performance win, anyhow.
536 			 */
537 			if ((f = fopen(appends[i].s, "r")) == NULL)
538 				break;
539 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
540 				(void)fwrite(buf, sizeof(char), count, outfile);
541 			(void)fclose(f);
542 			break;
543 		}
544 	if (ferror(outfile))
545 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
546 	appendx = sdone = 0;
547 }
548 
549 static void
550 lputs(char *s, size_t len)
551 {
552 	static const char escapes[] = "\\\a\b\f\r\t\v";
553 	int c, col, width;
554 	const char *p;
555 	struct winsize win;
556 	static int termwidth = -1;
557 	size_t clen, i;
558 	wchar_t wc;
559 	mbstate_t mbs;
560 
561 	if (outfile != stdout)
562 		termwidth = 60;
563 	if (termwidth == -1) {
564 		if ((p = getenv("COLUMNS")) && *p != '\0')
565 			termwidth = atoi(p);
566 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
567 		    win.ws_col > 0)
568 			termwidth = win.ws_col;
569 		else
570 			termwidth = 60;
571 	}
572 	if (termwidth <= 0)
573 		termwidth = 1;
574 
575 	memset(&mbs, 0, sizeof(mbs));
576 	col = 0;
577 	while (len != 0) {
578 		clen = mbrtowc(&wc, s, len, &mbs);
579 		if (clen == 0)
580 			clen = 1;
581 		if (clen == (size_t)-1 || clen == (size_t)-2) {
582 			wc = (unsigned char)*s;
583 			clen = 1;
584 			memset(&mbs, 0, sizeof(mbs));
585 		}
586 		if (wc == '\n') {
587 			if (col + 1 >= termwidth)
588 				fprintf(outfile, "\\\n");
589 			fputc('$', outfile);
590 			fputc('\n', outfile);
591 			col = 0;
592 		} else if (iswprint(wc)) {
593 			width = wcwidth(wc);
594 			if (col + width >= termwidth) {
595 				fprintf(outfile, "\\\n");
596 				col = 0;
597 			}
598 			fwrite(s, 1, clen, outfile);
599 			col += width;
600 		} else if (wc != L'\0' && (c = wctob(wc)) != EOF &&
601 		    (p = strchr(escapes, c)) != NULL) {
602 			if (col + 2 >= termwidth) {
603 				fprintf(outfile, "\\\n");
604 				col = 0;
605 			}
606 			fprintf(outfile, "\\%c", "\\abfrtv"[p - escapes]);
607 			col += 2;
608 		} else {
609 			if (col + 4 * clen >= (unsigned)termwidth) {
610 				fprintf(outfile, "\\\n");
611 				col = 0;
612 			}
613 			for (i = 0; i < clen; i++)
614 				fprintf(outfile, "\\%03o",
615 				    (int)(unsigned char)s[i]);
616 			col += 4 * clen;
617 		}
618 		s += clen;
619 		len -= clen;
620 	}
621 	if (col + 1 >= termwidth)
622 		fprintf(outfile, "\\\n");
623 	(void)fputc('$', outfile);
624 	(void)fputc('\n', outfile);
625 	if (ferror(outfile))
626 		errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
627 }
628 
629 static __inline int
630 regexec_e(regex_t *preg, const char *string, int eflags, int nomatch,
631 	  size_t slen)
632 {
633 	int eval;
634 
635 	if (preg == NULL) {
636 		if (defpreg == NULL)
637 			errx(1, "first RE may not be empty");
638 	} else
639 		defpreg = preg;
640 
641 	/* Set anchors */
642 	match[0].rm_so = 0;
643 	match[0].rm_eo = slen;
644 
645 	eval = regexec(defpreg, string,
646 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
647 	switch(eval) {
648 	case 0:
649 		return (1);
650 	case REG_NOMATCH:
651 		return (0);
652 	}
653 	errx(1, "RE error: %s", strregerror(eval, defpreg));
654 	/* NOTREACHED */
655 }
656 
657 /*
658  * regsub - perform substitutions after a regexp match
659  * Based on a routine by Henry Spencer
660  */
661 static void
662 regsub(SPACE *sp, char *string, char *src)
663 {
664 	int len, no;
665 	char c, *dst;
666 
667 #define	NEEDSP(reqlen)							\
668 	/* XXX What is the +1 for? */					\
669 	if (sp->len + (reqlen) + 1 >= sp->blen) {			\
670 		sp->blen += (reqlen) + 1024;				\
671 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
672 		    == NULL)						\
673 			err(1, "realloc");				\
674 		dst = sp->space + sp->len;				\
675 	}
676 
677 	dst = sp->space + sp->len;
678 	while ((c = *src++) != '\0') {
679 		if (c == '&')
680 			no = 0;
681 		else if (c == '\\' && isdigit((unsigned char)*src))
682 			no = *src++ - '0';
683 		else
684 			no = -1;
685 		if (no < 0) {		/* Ordinary character. */
686 			if (c == '\\' && (*src == '\\' || *src == '&'))
687 				c = *src++;
688 			NEEDSP(1);
689 			*dst++ = c;
690 			++sp->len;
691 		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
692 			len = match[no].rm_eo - match[no].rm_so;
693 			NEEDSP(len);
694 			memmove(dst, string + match[no].rm_so, len);
695 			dst += len;
696 			sp->len += len;
697 		}
698 	}
699 	NEEDSP(1);
700 	*dst = '\0';
701 }
702 
703 /*
704  * cspace --
705  *	Concatenate space: append the source space to the destination space,
706  *	allocating new space as necessary.
707  */
708 void
709 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
710 {
711 	size_t tlen;
712 
713 	/* Make sure SPACE has enough memory and ramp up quickly. */
714 	tlen = sp->len + len + 1;
715 	if (tlen > sp->blen) {
716 		sp->blen = tlen + 1024;
717 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
718 		    NULL)
719 			err(1, "realloc");
720 	}
721 
722 	if (spflag == REPLACE)
723 		sp->len = 0;
724 
725 	memmove(sp->space + sp->len, p, len);
726 
727 	sp->space[sp->len += len] = '\0';
728 }
729 
730 /*
731  * Close all cached opened files and report any errors
732  */
733 void
734 cfclose(struct s_command *cp, struct s_command *end)
735 {
736 
737 	for (; cp != end; cp = cp->next)
738 		switch(cp->code) {
739 		case 's':
740 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
741 				err(1, "%s", cp->u.s->wfile);
742 			cp->u.s->wfd = -1;
743 			break;
744 		case 'w':
745 			if (cp->u.fd != -1 && close(cp->u.fd))
746 				err(1, "%s", cp->t);
747 			cp->u.fd = -1;
748 			break;
749 		case '{':
750 			cfclose(cp->u.c, cp->next);
751 			break;
752 		}
753 }
754