xref: /freebsd/usr.bin/sed/process.c (revision 2a4a1db342263067035ce69a4017c645da63455d)
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("$FreeBSD$");
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); }
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 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
100 		pd = 0;
101 top:
102 		cp = prog;
103 redirect:
104 		while (cp != NULL) {
105 			if (!applies(cp)) {
106 				cp = cp->next;
107 				continue;
108 			}
109 			switch (cp->code) {
110 			case '{':
111 				cp = cp->u.c;
112 				goto redirect;
113 			case 'a':
114 				if (appendx >= appendnum)
115 					if ((appends = realloc(appends,
116 					    sizeof(struct s_appends) *
117 					    (appendnum *= 2))) == NULL)
118 						err(1, "realloc");
119 				appends[appendx].type = AP_STRING;
120 				appends[appendx].s = cp->t;
121 				appends[appendx].len = strlen(cp->t);
122 				appendx++;
123 				break;
124 			case 'b':
125 				cp = cp->u.c;
126 				goto redirect;
127 			case 'c':
128 				pd = 1;
129 				psl = 0;
130 				if (cp->a2 == NULL || lastaddr)
131 					(void)printf("%s", cp->t);
132 				break;
133 			case 'd':
134 				pd = 1;
135 				goto new;
136 			case 'D':
137 				if (pd)
138 					goto new;
139 				if (psl == 0 ||
140 				    (p = memchr(ps, '\n', psl - 1)) == NULL) {
141 					pd = 1;
142 					goto new;
143 				} else {
144 					psl -= (p + 1) - ps;
145 					memmove(ps, p + 1, psl);
146 					goto top;
147 				}
148 			case 'g':
149 				cspace(&PS, hs, hsl, REPLACE);
150 				break;
151 			case 'G':
152 				if (hs == NULL)
153 					cspace(&HS, "\n", 1, REPLACE);
154 				cspace(&PS, hs, hsl, 0);
155 				break;
156 			case 'h':
157 				cspace(&HS, ps, psl, REPLACE);
158 				break;
159 			case 'H':
160 				cspace(&HS, ps, psl, 0);
161 				break;
162 			case 'i':
163 				(void)printf("%s", cp->t);
164 				break;
165 			case 'l':
166 				lputs(ps);
167 				break;
168 			case 'n':
169 				if (!nflag && !pd)
170 					OUT(ps)
171 				flush_appends();
172 				if (!mf_fgets(&PS, REPLACE))
173 					exit(0);
174 				pd = 0;
175 				break;
176 			case 'N':
177 				flush_appends();
178 				if (!mf_fgets(&PS, 0)) {
179 					if (!nflag && !pd)
180 						OUT(ps)
181 					exit(0);
182 				}
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 - 1)) != NULL) {
194 					oldpsl = psl;
195 					psl = (p + 1) - 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 					err(1, "%s", cp->t);
236 				break;
237 			case 'x':
238 				if (hs == NULL)
239 					cspace(&HS, "\n", 1, REPLACE);
240 				tspace = PS;
241 				PS = HS;
242 				HS = tspace;
243 				break;
244 			case 'y':
245 				if (pd || psl == 0)
246 					break;
247 				for (p = ps, len = psl; --len; ++p)
248 					*p = cp->u.y[(unsigned char)*p];
249 				break;
250 			case ':':
251 			case '}':
252 				break;
253 			case '=':
254 				(void)printf("%lu\n", linenum);
255 			}
256 			cp = cp->next;
257 		} /* for all cp */
258 
259 new:		if (!nflag && !pd)
260 			OUT(ps)
261 		flush_appends();
262 	} /* for all lines */
263 }
264 
265 /*
266  * TRUE if the address passed matches the current program state
267  * (lastline, linenumber, ps).
268  */
269 #define	MATCH(a)						\
270 	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
271 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline
272 
273 /*
274  * Return TRUE if the command applies to the current line.  Sets the inrange
275  * flag to process ranges.  Interprets the non-select (``!'') flag.
276  */
277 static inline int
278 applies(cp)
279 	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 			}
292 			r = 1;
293 		} else if (MATCH(cp->a1)) {
294 			/*
295 			 * If the second address is a number less than or
296 			 * equal to the line number first selected, only
297 			 * one line shall be selected.
298 			 *	-- POSIX 1003.2
299 			 */
300 			if (cp->a2->type == AT_LINE &&
301 			    linenum >= cp->a2->u.l)
302 				lastaddr = 1;
303 			else
304 				cp->inrange = 1;
305 			r = 1;
306 		} else
307 			r = 0;
308 	else
309 		r = MATCH(cp->a1);
310 	return (cp->nonsel ? ! r : r);
311 }
312 
313 /*
314  * substitute --
315  *	Do substitutions in the pattern space.  Currently, we build a
316  *	copy of the new pattern space in the substitute space structure
317  *	and then swap them.
318  */
319 static int
320 substitute(cp)
321 	struct s_command *cp;
322 {
323 	SPACE tspace;
324 	regex_t *re;
325 	size_t re_off, slen;
326 	int lastempty, n;
327 	char *s;
328 
329 	s = ps;
330 	re = cp->u.s->re;
331 	if (re == NULL) {
332 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
333 			linenum = cp->u.s->linenum;
334 			errx(1, "%lu: %s: \\%d not defined in the RE",
335 					linenum, fname, cp->u.s->maxbref);
336 		}
337 	}
338 	if (!regexec_e(re, s, 0, 0, psl))
339 		return (0);
340 
341   	SS.len = 0;				/* Clean substitute space. */
342   	slen = psl;
343   	n = cp->u.s->n;
344 	lastempty = 1;
345 
346   	switch (n) {
347   	case 0:					/* Global */
348   		do {
349 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
350 				/* Locate start of replaced string. */
351 				re_off = match[0].rm_so;
352 				/* Copy leading retained string. */
353 				cspace(&SS, s, re_off, APPEND);
354 				/* Add in regular expression. */
355 				regsub(&SS, s, cp->u.s->new);
356 			}
357 
358 			/* Move past this match. */
359 			if (match[0].rm_so != match[0].rm_eo) {
360 				s += match[0].rm_eo;
361 				slen -= match[0].rm_eo;
362 				lastempty = 0;
363 			} else {
364 				if (match[0].rm_so == 0)
365 					cspace(&SS, s, match[0].rm_so + 1,
366 					    APPEND);
367 				else
368 					cspace(&SS, s + match[0].rm_so, 1,
369 					    APPEND);
370 				s += match[0].rm_so + 1;
371 				slen -= match[0].rm_so + 1;
372 				lastempty = 1;
373 			}
374 		} while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
375 		/* Copy trailing retained string. */
376 		if (slen > 0)
377 			cspace(&SS, s, slen, APPEND);
378   		break;
379 	default:				/* Nth occurrence */
380 		while (--n) {
381 			s += match[0].rm_eo;
382 			slen -= match[0].rm_eo;
383 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
384 				return (0);
385 		}
386 		/* FALLTHROUGH */
387 	case 1:					/* 1st occurrence */
388 		/* Locate start of replaced string. */
389 		re_off = match[0].rm_so + (s - ps);
390 		/* Copy leading retained string. */
391 		cspace(&SS, ps, re_off, APPEND);
392 		/* Add in regular expression. */
393 		regsub(&SS, s, cp->u.s->new);
394 		/* Copy trailing retained string. */
395 		s += match[0].rm_eo;
396 		slen -= match[0].rm_eo;
397 		cspace(&SS, s, slen, APPEND);
398 		break;
399 	}
400 
401 	/*
402 	 * Swap the substitute space and the pattern space, and make sure
403 	 * that any leftover pointers into stdio memory get lost.
404 	 */
405 	tspace = PS;
406 	PS = SS;
407 	SS = tspace;
408 	SS.space = SS.back;
409 
410 	/* Handle the 'p' flag. */
411 	if (cp->u.s->p)
412 		OUT(ps)
413 
414 	/* Handle the 'w' flag. */
415 	if (cp->u.s->wfile && !pd) {
416 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
417 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
418 			err(1, "%s", cp->u.s->wfile);
419 		if (write(cp->u.s->wfd, ps, psl) != psl)
420 			err(1, "%s", cp->u.s->wfile);
421 	}
422 	return (1);
423 }
424 
425 /*
426  * Flush append requests.  Always called before reading a line,
427  * therefore it also resets the substitution done (sdone) flag.
428  */
429 static void
430 flush_appends()
431 {
432 	FILE *f;
433 	int count, i;
434 	char buf[8 * 1024];
435 
436 	for (i = 0; i < appendx; i++)
437 		switch (appends[i].type) {
438 		case AP_STRING:
439 			fwrite(appends[i].s, sizeof(char), appends[i].len,
440 			    stdout);
441 			break;
442 		case AP_FILE:
443 			/*
444 			 * Read files probably shouldn't be cached.  Since
445 			 * it's not an error to read a non-existent file,
446 			 * it's possible that another program is interacting
447 			 * with the sed script through the filesystem.  It
448 			 * would be truly bizarre, but possible.  It's probably
449 			 * not that big a performance win, anyhow.
450 			 */
451 			if ((f = fopen(appends[i].s, "r")) == NULL)
452 				break;
453 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
454 				(void)fwrite(buf, sizeof(char), count, stdout);
455 			(void)fclose(f);
456 			break;
457 		}
458 	if (ferror(stdout))
459 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
460 	appendx = sdone = 0;
461 }
462 
463 static void
464 lputs(s)
465 	char *s;
466 {
467 	int count;
468 	char *escapes, *p;
469 	struct winsize win;
470 	static int termwidth = -1;
471 
472 	if (termwidth == -1) {
473 		if ((p = getenv("COLUMNS")))
474 			termwidth = atoi(p);
475 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
476 		    win.ws_col > 0)
477 			termwidth = win.ws_col;
478 		else
479 			termwidth = 60;
480 	}
481 
482 	for (count = 0; *s; ++s) {
483 		if (count >= termwidth) {
484 			(void)printf("\\\n");
485 			count = 0;
486 		}
487 		if (isprint((unsigned char)*s) && *s != '\\') {
488 			(void)putchar(*s);
489 			count++;
490 		} else {
491 			escapes = "\\\a\b\f\n\r\t\v";
492 			(void)putchar('\\');
493 			if ((p = strchr(escapes, *s))) {
494 				(void)putchar("\\abfnrtv"[p - escapes]);
495 				count += 2;
496 			} else {
497 				(void)printf("%03o", *(u_char *)s);
498 				count += 4;
499 			}
500 		}
501 	}
502 	(void)putchar('$');
503 	(void)putchar('\n');
504 	if (ferror(stdout))
505 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
506 }
507 
508 static inline int
509 regexec_e(preg, string, eflags, nomatch, slen)
510 	regex_t *preg;
511 	const char *string;
512 	int eflags, nomatch;
513 	size_t slen;
514 {
515 	int eval;
516 
517 	if (preg == NULL) {
518 		if (defpreg == NULL)
519 			errx(1, "first RE may not be empty");
520 	} else
521 		defpreg = preg;
522 
523 	/* Set anchors, discounting trailing newline (if any). */
524 	if (slen > 0 && string[slen - 1] == '\n')
525 		slen--;
526 	match[0].rm_so = 0;
527 	match[0].rm_eo = slen;
528 
529 	eval = regexec(defpreg, string,
530 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
531 	switch(eval) {
532 	case 0:
533 		return (1);
534 	case REG_NOMATCH:
535 		return (0);
536 	}
537 	errx(1, "RE error: %s", strregerror(eval, defpreg));
538 	/* NOTREACHED */
539 }
540 
541 /*
542  * regsub - perform substitutions after a regexp match
543  * Based on a routine by Henry Spencer
544  */
545 static void
546 regsub(sp, string, src)
547 	SPACE *sp;
548 	char *string, *src;
549 {
550 	int len, no;
551 	char c, *dst;
552 
553 #define	NEEDSP(reqlen)							\
554 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
555 		sp->blen += (reqlen) + 1024;				\
556 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
557 		    == NULL)						\
558 			err(1, "realloc");				\
559 		dst = sp->space + sp->len;				\
560 	}
561 
562 	dst = sp->space + sp->len;
563 	while ((c = *src++) != '\0') {
564 		if (c == '&')
565 			no = 0;
566 		else if (c == '\\' && isdigit((unsigned char)*src))
567 			no = *src++ - '0';
568 		else
569 			no = -1;
570 		if (no < 0) {		/* Ordinary character. */
571  			if (c == '\\' && (*src == '\\' || *src == '&'))
572  				c = *src++;
573 			NEEDSP(1);
574  			*dst++ = c;
575 			++sp->len;
576  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
577 			len = match[no].rm_eo - match[no].rm_so;
578 			NEEDSP(len);
579 			memmove(dst, string + match[no].rm_so, len);
580 			dst += len;
581 			sp->len += len;
582 		}
583 	}
584 	NEEDSP(1);
585 	*dst = '\0';
586 }
587 
588 /*
589  * aspace --
590  *	Append the source space to the destination space, allocating new
591  *	space as necessary.
592  */
593 void
594 cspace(sp, p, len, spflag)
595 	SPACE *sp;
596 	char *p;
597 	size_t len;
598 	enum e_spflag spflag;
599 {
600 	size_t tlen;
601 
602 	/* Make sure SPACE has enough memory and ramp up quickly. */
603 	tlen = sp->len + len + 1;
604 	if (tlen > sp->blen) {
605 		sp->blen = tlen + 1024;
606 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
607 		    NULL)
608 			err(1, "realloc");
609 	}
610 
611 	if (spflag == REPLACE)
612 		sp->len = 0;
613 
614 	memmove(sp->space + sp->len, p, len);
615 
616 	sp->space[sp->len += len] = '\0';
617 }
618 
619 /*
620  * Close all cached opened files and report any errors
621  */
622 void
623 cfclose(cp, end)
624 	struct s_command *cp, *end;
625 {
626 
627 	for (; cp != end; cp = cp->next)
628 		switch(cp->code) {
629 		case 's':
630 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
631 				err(1, "%s", cp->u.s->wfile);
632 			cp->u.s->wfd = -1;
633 			break;
634 		case 'w':
635 			if (cp->u.fd != -1 && close(cp->u.fd))
636 				err(1, "%s", cp->t);
637 			cp->u.fd = -1;
638 			break;
639 		case '{':
640 			cfclose(cp->u.c, cp->next);
641 			break;
642 		}
643 }
644