xref: /dragonfly/usr.bin/sed/process.c (revision 984263bc)
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. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD: src/usr.bin/sed/process.c,v 1.10.2.10 2003/06/13 07:32:08 fanf Exp $");
40 
41 #ifndef lint
42 static const char sccsid[] = "@(#)process.c	8.6 (Berkeley) 4/20/94";
43 #endif
44 
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 #include <sys/ioctl.h>
48 #include <sys/uio.h>
49 
50 #include <ctype.h>
51 #include <err.h>
52 #include <errno.h>
53 #include <fcntl.h>
54 #include <limits.h>
55 #include <regex.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 
61 #include "defs.h"
62 #include "extern.h"
63 
64 static SPACE HS, PS, SS;
65 #define	pd		PS.deleted
66 #define	ps		PS.space
67 #define	psl		PS.len
68 #define	hs		HS.space
69 #define	hsl		HS.len
70 
71 static __inline int	 applies(struct s_command *);
72 static void		 flush_appends(void);
73 static void		 lputs(char *);
74 static __inline int	 regexec_e(regex_t *, const char *, int, int, size_t);
75 static void		 regsub(SPACE *, char *, char *);
76 static int		 substitute(struct s_command *);
77 
78 struct s_appends *appends;	/* Array of pointers to strings to append. */
79 static int appendx;		/* Index into appends array. */
80 int appendnum;			/* Size of appends array. */
81 
82 static int lastaddr;		/* Set by applies if last address of a range. */
83 static int sdone;		/* If any substitutes since last line input. */
84 				/* Iov structure for 'w' commands. */
85 static regex_t *defpreg;
86 size_t maxnsub;
87 regmatch_t *match;
88 
89 #define OUT(s) { fwrite(s, sizeof(u_char), psl, stdout); putchar('\n'); }
90 
91 void
92 process()
93 {
94 	struct s_command *cp;
95 	SPACE tspace;
96 	size_t len, oldpsl = 0;
97 	char *p;
98 
99 	p = NULL;
100 
101 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
102 		pd = 0;
103 top:
104 		cp = prog;
105 redirect:
106 		while (cp != NULL) {
107 			if (!applies(cp)) {
108 				cp = cp->next;
109 				continue;
110 			}
111 			switch (cp->code) {
112 			case '{':
113 				cp = cp->u.c;
114 				goto redirect;
115 			case 'a':
116 				if (appendx >= appendnum)
117 					if ((appends = realloc(appends,
118 					    sizeof(struct s_appends) *
119 					    (appendnum *= 2))) == NULL)
120 						err(1, "realloc");
121 				appends[appendx].type = AP_STRING;
122 				appends[appendx].s = cp->t;
123 				appends[appendx].len = strlen(cp->t);
124 				appendx++;
125 				break;
126 			case 'b':
127 				cp = cp->u.c;
128 				goto redirect;
129 			case 'c':
130 				pd = 1;
131 				psl = 0;
132 				if (cp->a2 == NULL || lastaddr)
133 					(void)printf("%s", cp->t);
134 				break;
135 			case 'd':
136 				pd = 1;
137 				goto new;
138 			case 'D':
139 				if (pd)
140 					goto new;
141 				if (psl == 0 ||
142 				    (p = memchr(ps, '\n', psl)) == NULL) {
143 					pd = 1;
144 					goto new;
145 				} else {
146 					psl -= (p + 1) - ps;
147 					memmove(ps, p + 1, psl);
148 					goto top;
149 				}
150 			case 'g':
151 				cspace(&PS, hs, hsl, REPLACE);
152 				break;
153 			case 'G':
154 				cspace(&PS, "\n", 1, 0);
155 				cspace(&PS, hs, hsl, 0);
156 				break;
157 			case 'h':
158 				cspace(&HS, ps, psl, REPLACE);
159 				break;
160 			case 'H':
161 				cspace(&HS, "\n", 1, 0);
162 				cspace(&HS, ps, psl, 0);
163 				break;
164 			case 'i':
165 				(void)printf("%s", cp->t);
166 				break;
167 			case 'l':
168 				lputs(ps);
169 				break;
170 			case 'n':
171 				if (!nflag && !pd)
172 					OUT(ps)
173 				flush_appends();
174 				if (!mf_fgets(&PS, REPLACE))
175 					exit(0);
176 				pd = 0;
177 				break;
178 			case 'N':
179 				flush_appends();
180 				cspace(&PS, "\n", 1, 0);
181 				if (!mf_fgets(&PS, 0))
182 					exit(0);
183 				break;
184 			case 'p':
185 				if (pd)
186 					break;
187 				OUT(ps)
188 				break;
189 			case 'P':
190 				if (pd)
191 					break;
192 				if (psl != 0 &&
193 				    (p = memchr(ps, '\n', psl)) != NULL) {
194 					oldpsl = psl;
195 					psl = p - ps;
196 				}
197 				OUT(ps)
198 				if (p != NULL)
199 					psl = oldpsl;
200 				break;
201 			case 'q':
202 				if (!nflag && !pd)
203 					OUT(ps)
204 				flush_appends();
205 				exit(0);
206 			case 'r':
207 				if (appendx >= appendnum)
208 					if ((appends = realloc(appends,
209 					    sizeof(struct s_appends) *
210 					    (appendnum *= 2))) == NULL)
211 						err(1, "realloc");
212 				appends[appendx].type = AP_FILE;
213 				appends[appendx].s = cp->t;
214 				appends[appendx].len = strlen(cp->t);
215 				appendx++;
216 				break;
217 			case 's':
218 				sdone |= substitute(cp);
219 				break;
220 			case 't':
221 				if (sdone) {
222 					sdone = 0;
223 					cp = cp->u.c;
224 					goto redirect;
225 				}
226 				break;
227 			case 'w':
228 				if (pd)
229 					break;
230 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
231 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
232 				    DEFFILEMODE)) == -1)
233 					err(1, "%s", cp->t);
234 				if (write(cp->u.fd, ps, psl) != psl ||
235 				    write(cp->u.fd, "\n", 1) != 1)
236 					err(1, "%s", cp->t);
237 				break;
238 			case 'x':
239 				if (hs == NULL)
240 					cspace(&HS, "", 0, REPLACE);
241 				tspace = PS;
242 				PS = HS;
243 				HS = tspace;
244 				break;
245 			case 'y':
246 				if (pd || psl == 0)
247 					break;
248 				for (p = ps, len = psl; len--; ++p)
249 					*p = cp->u.y[(unsigned char)*p];
250 				break;
251 			case ':':
252 			case '}':
253 				break;
254 			case '=':
255 				(void)printf("%lu\n", linenum);
256 			}
257 			cp = cp->next;
258 		} /* for all cp */
259 
260 new:		if (!nflag && !pd)
261 			OUT(ps)
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(cp)
280 	struct s_command *cp;
281 {
282 	int r;
283 
284 	lastaddr = 0;
285 	if (cp->a1 == NULL && cp->a2 == NULL)
286 		r = 1;
287 	else if (cp->a2)
288 		if (cp->inrange) {
289 			if (MATCH(cp->a2)) {
290 				cp->inrange = 0;
291 				lastaddr = 1;
292 			}
293 			r = 1;
294 		} else if (MATCH(cp->a1)) {
295 			/*
296 			 * If the second address is a number less than or
297 			 * equal to the line number first selected, only
298 			 * one line shall be selected.
299 			 *	-- POSIX 1003.2
300 			 */
301 			if (cp->a2->type == AT_LINE &&
302 			    linenum >= cp->a2->u.l)
303 				lastaddr = 1;
304 			else
305 				cp->inrange = 1;
306 			r = 1;
307 		} else
308 			r = 0;
309 	else
310 		r = MATCH(cp->a1);
311 	return (cp->nonsel ? ! r : r);
312 }
313 
314 /*
315  * substitute --
316  *	Do substitutions in the pattern space.  Currently, we build a
317  *	copy of the new pattern space in the substitute space structure
318  *	and then swap them.
319  */
320 static int
321 substitute(cp)
322 	struct s_command *cp;
323 {
324 	SPACE tspace;
325 	regex_t *re;
326 	regoff_t re_off, slen;
327 	int lastempty, n;
328 	char *s;
329 
330 	s = ps;
331 	re = cp->u.s->re;
332 	if (re == NULL) {
333 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
334 			linenum = cp->u.s->linenum;
335 			errx(1, "%lu: %s: \\%d not defined in the RE",
336 					linenum, fname, cp->u.s->maxbref);
337 		}
338 	}
339 	if (!regexec_e(re, s, 0, 0, psl))
340 		return (0);
341 
342   	SS.len = 0;				/* Clean substitute space. */
343   	slen = psl;
344   	n = cp->u.s->n;
345 	lastempty = 1;
346 
347   	switch (n) {
348   	case 0:					/* Global */
349   		do {
350 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
351 				/* Locate start of replaced string. */
352 				re_off = match[0].rm_so;
353 				/* Copy leading retained string. */
354 				cspace(&SS, s, re_off, APPEND);
355 				/* Add in regular expression. */
356 				regsub(&SS, s, cp->u.s->new);
357 			}
358 
359 			/* Move past this match. */
360 			if (match[0].rm_so != match[0].rm_eo) {
361 				s += match[0].rm_eo;
362 				slen -= match[0].rm_eo;
363 				lastempty = 0;
364 			} else {
365 				if (match[0].rm_so < slen)
366 					cspace(&SS, s + match[0].rm_so, 1,
367 					    APPEND);
368 				s += match[0].rm_so + 1;
369 				slen -= match[0].rm_so + 1;
370 				lastempty = 1;
371 			}
372 		} while (slen >= 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
373 		/* Copy trailing retained string. */
374 		if (slen > 0)
375 			cspace(&SS, s, slen, APPEND);
376   		break;
377 	default:				/* Nth occurrence */
378 		while (--n) {
379 			if (match[0].rm_eo == match[0].rm_so)
380 				match[0].rm_eo = match[0].rm_so + 1;
381 			s += match[0].rm_eo;
382 			slen -= match[0].rm_eo;
383 			if (slen < 0)
384 				return (0);
385 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
386 				return (0);
387 		}
388 		/* FALLTHROUGH */
389 	case 1:					/* 1st occurrence */
390 		/* Locate start of replaced string. */
391 		re_off = match[0].rm_so + (s - ps);
392 		/* Copy leading retained string. */
393 		cspace(&SS, ps, re_off, APPEND);
394 		/* Add in regular expression. */
395 		regsub(&SS, s, cp->u.s->new);
396 		/* Copy trailing retained string. */
397 		s += match[0].rm_eo;
398 		slen -= match[0].rm_eo;
399 		cspace(&SS, s, slen, APPEND);
400 		break;
401 	}
402 
403 	/*
404 	 * Swap the substitute space and the pattern space, and make sure
405 	 * that any leftover pointers into stdio memory get lost.
406 	 */
407 	tspace = PS;
408 	PS = SS;
409 	SS = tspace;
410 	SS.space = SS.back;
411 
412 	/* Handle the 'p' flag. */
413 	if (cp->u.s->p)
414 		OUT(ps)
415 
416 	/* Handle the 'w' flag. */
417 	if (cp->u.s->wfile && !pd) {
418 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
419 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
420 			err(1, "%s", cp->u.s->wfile);
421 		if (write(cp->u.s->wfd, ps, psl) != psl ||
422 		    write(cp->u.s->wfd, "\n", 1) != 1)
423 			err(1, "%s", cp->u.s->wfile);
424 	}
425 	return (1);
426 }
427 
428 /*
429  * Flush append requests.  Always called before reading a line,
430  * therefore it also resets the substitution done (sdone) flag.
431  */
432 static void
433 flush_appends()
434 {
435 	FILE *f;
436 	int count, i;
437 	char buf[8 * 1024];
438 
439 	for (i = 0; i < appendx; i++)
440 		switch (appends[i].type) {
441 		case AP_STRING:
442 			fwrite(appends[i].s, sizeof(char), appends[i].len,
443 			    stdout);
444 			break;
445 		case AP_FILE:
446 			/*
447 			 * Read files probably shouldn't be cached.  Since
448 			 * it's not an error to read a non-existent file,
449 			 * it's possible that another program is interacting
450 			 * with the sed script through the filesystem.  It
451 			 * would be truly bizarre, but possible.  It's probably
452 			 * not that big a performance win, anyhow.
453 			 */
454 			if ((f = fopen(appends[i].s, "r")) == NULL)
455 				break;
456 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
457 				(void)fwrite(buf, sizeof(char), count, stdout);
458 			(void)fclose(f);
459 			break;
460 		}
461 	if (ferror(stdout))
462 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
463 	appendx = sdone = 0;
464 }
465 
466 static void
467 lputs(s)
468 	char *s;
469 {
470 	int count;
471 	const char *escapes;
472 	char *p;
473 	struct winsize win;
474 	static int termwidth = -1;
475 
476 	if (termwidth == -1) {
477 		if ((p = getenv("COLUMNS")) && *p != '\0')
478 			termwidth = atoi(p);
479 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
480 		    win.ws_col > 0)
481 			termwidth = win.ws_col;
482 		else
483 			termwidth = 60;
484 	}
485 
486 	for (count = 0; *s; ++s) {
487 		if (count + 5 >= termwidth) {
488 			(void)printf("\\\n");
489 			count = 0;
490 		}
491 		if (isprint((unsigned char)*s) && *s != '\\') {
492 			(void)putchar(*s);
493 			count++;
494 		} else if (*s == '\n') {
495 			(void)putchar('$');
496 			(void)putchar('\n');
497 			count = 0;
498 		} else {
499 			escapes = "\\\a\b\f\r\t\v";
500 			(void)putchar('\\');
501 			if ((p = strchr(escapes, *s))) {
502 				(void)putchar("\\abfrtv"[p - escapes]);
503 				count += 2;
504 			} else {
505 				(void)printf("%03o", *(u_char *)s);
506 				count += 4;
507 			}
508 		}
509 	}
510 	(void)putchar('$');
511 	(void)putchar('\n');
512 	if (ferror(stdout))
513 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
514 }
515 
516 static __inline int
517 regexec_e(preg, string, eflags, nomatch, slen)
518 	regex_t *preg;
519 	const char *string;
520 	int eflags, nomatch;
521 	size_t slen;
522 {
523 	int eval;
524 
525 	if (preg == NULL) {
526 		if (defpreg == NULL)
527 			errx(1, "first RE may not be empty");
528 	} else
529 		defpreg = preg;
530 
531 	/* Set anchors */
532 	match[0].rm_so = 0;
533 	match[0].rm_eo = slen;
534 
535 	eval = regexec(defpreg, string,
536 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
537 	switch(eval) {
538 	case 0:
539 		return (1);
540 	case REG_NOMATCH:
541 		return (0);
542 	}
543 	errx(1, "RE error: %s", strregerror(eval, defpreg));
544 	/* NOTREACHED */
545 }
546 
547 /*
548  * regsub - perform substitutions after a regexp match
549  * Based on a routine by Henry Spencer
550  */
551 static void
552 regsub(sp, string, src)
553 	SPACE *sp;
554 	char *string, *src;
555 {
556 	int len, no;
557 	char c, *dst;
558 
559 #define	NEEDSP(reqlen)							\
560 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
561 		sp->blen += (reqlen) + 1024;				\
562 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
563 		    == NULL)						\
564 			err(1, "realloc");				\
565 		dst = sp->space + sp->len;				\
566 	}
567 
568 	dst = sp->space + sp->len;
569 	while ((c = *src++) != '\0') {
570 		if (c == '&')
571 			no = 0;
572 		else if (c == '\\' && isdigit((unsigned char)*src))
573 			no = *src++ - '0';
574 		else
575 			no = -1;
576 		if (no < 0) {		/* Ordinary character. */
577  			if (c == '\\' && (*src == '\\' || *src == '&'))
578  				c = *src++;
579 			NEEDSP(1);
580  			*dst++ = c;
581 			++sp->len;
582  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
583 			len = match[no].rm_eo - match[no].rm_so;
584 			NEEDSP(len);
585 			memmove(dst, string + match[no].rm_so, len);
586 			dst += len;
587 			sp->len += len;
588 		}
589 	}
590 	NEEDSP(1);
591 	*dst = '\0';
592 }
593 
594 /*
595  * aspace --
596  *	Append the source space to the destination space, allocating new
597  *	space as necessary.
598  */
599 void
600 cspace(sp, p, len, spflag)
601 	SPACE *sp;
602 	const char *p;
603 	size_t len;
604 	enum e_spflag spflag;
605 {
606 	size_t tlen;
607 
608 	/* Make sure SPACE has enough memory and ramp up quickly. */
609 	tlen = sp->len + len + 1;
610 	if (tlen > sp->blen) {
611 		sp->blen = tlen + 1024;
612 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
613 		    NULL)
614 			err(1, "realloc");
615 	}
616 
617 	if (spflag == REPLACE)
618 		sp->len = 0;
619 
620 	memmove(sp->space + sp->len, p, len);
621 
622 	sp->space[sp->len += len] = '\0';
623 }
624 
625 /*
626  * Close all cached opened files and report any errors
627  */
628 void
629 cfclose(cp, end)
630 	struct s_command *cp, *end;
631 {
632 
633 	for (; cp != end; cp = cp->next)
634 		switch(cp->code) {
635 		case 's':
636 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
637 				err(1, "%s", cp->u.s->wfile);
638 			cp->u.s->wfd = -1;
639 			break;
640 		case 'w':
641 			if (cp->u.fd != -1 && close(cp->u.fd))
642 				err(1, "%s", cp->t);
643 			cp->u.fd = -1;
644 			break;
645 		case '{':
646 			cfclose(cp->u.c, cp->next);
647 			break;
648 		}
649 }
650