xref: /freebsd/usr.bin/sed/process.c (revision ae83180158c4c937f170e31eff311b18c0286a93)
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); 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 	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)) == 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 				cspace(&PS, "\n", 1, 0);
153 				cspace(&PS, hs, hsl, 0);
154 				break;
155 			case 'h':
156 				cspace(&HS, ps, psl, REPLACE);
157 				break;
158 			case 'H':
159 				cspace(&HS, "\n", 1, 0);
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 				cspace(&PS, "\n", 1, 0);
179 				if (!mf_fgets(&PS, 0))
180 					exit(0);
181 				break;
182 			case 'p':
183 				if (pd)
184 					break;
185 				OUT(ps)
186 				break;
187 			case 'P':
188 				if (pd)
189 					break;
190 				if (psl != 0 &&
191 				    (p = memchr(ps, '\n', psl)) != NULL) {
192 					oldpsl = psl;
193 					psl = p - ps;
194 				}
195 				OUT(ps)
196 				if (p != NULL)
197 					psl = oldpsl;
198 				break;
199 			case 'q':
200 				if (!nflag && !pd)
201 					OUT(ps)
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 				if (hs == NULL)
238 					cspace(&HS, "", 0, REPLACE);
239 				tspace = PS;
240 				PS = HS;
241 				HS = tspace;
242 				break;
243 			case 'y':
244 				if (pd || psl == 0)
245 					break;
246 				for (p = ps, len = psl; len--; ++p)
247 					*p = cp->u.y[(unsigned char)*p];
248 				break;
249 			case ':':
250 			case '}':
251 				break;
252 			case '=':
253 				(void)printf("%lu\n", linenum);
254 			}
255 			cp = cp->next;
256 		} /* for all cp */
257 
258 new:		if (!nflag && !pd)
259 			OUT(ps)
260 		flush_appends();
261 	} /* for all lines */
262 }
263 
264 /*
265  * TRUE if the address passed matches the current program state
266  * (lastline, linenumber, ps).
267  */
268 #define	MATCH(a)						\
269 	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
270 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline()
271 
272 /*
273  * Return TRUE if the command applies to the current line.  Sets the inrange
274  * flag to process ranges.  Interprets the non-select (``!'') flag.
275  */
276 static __inline int
277 applies(cp)
278 	struct s_command *cp;
279 {
280 	int r;
281 
282 	lastaddr = 0;
283 	if (cp->a1 == NULL && cp->a2 == NULL)
284 		r = 1;
285 	else if (cp->a2)
286 		if (cp->inrange) {
287 			if (MATCH(cp->a2)) {
288 				cp->inrange = 0;
289 				lastaddr = 1;
290 			}
291 			r = 1;
292 		} else if (MATCH(cp->a1)) {
293 			/*
294 			 * If the second address is a number less than or
295 			 * equal to the line number first selected, only
296 			 * one line shall be selected.
297 			 *	-- POSIX 1003.2
298 			 */
299 			if (cp->a2->type == AT_LINE &&
300 			    linenum >= cp->a2->u.l)
301 				lastaddr = 1;
302 			else
303 				cp->inrange = 1;
304 			r = 1;
305 		} else
306 			r = 0;
307 	else
308 		r = MATCH(cp->a1);
309 	return (cp->nonsel ? ! r : r);
310 }
311 
312 /*
313  * substitute --
314  *	Do substitutions in the pattern space.  Currently, we build a
315  *	copy of the new pattern space in the substitute space structure
316  *	and then swap them.
317  */
318 static int
319 substitute(cp)
320 	struct s_command *cp;
321 {
322 	SPACE tspace;
323 	regex_t *re;
324 	size_t re_off, slen;
325 	int lastempty, n;
326 	char *s;
327 
328 	s = ps;
329 	re = cp->u.s->re;
330 	if (re == NULL) {
331 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
332 			linenum = cp->u.s->linenum;
333 			errx(1, "%lu: %s: \\%d not defined in the RE",
334 					linenum, fname, cp->u.s->maxbref);
335 		}
336 	}
337 	if (!regexec_e(re, s, 0, 0, psl))
338 		return (0);
339 
340   	SS.len = 0;				/* Clean substitute space. */
341   	slen = psl;
342   	n = cp->u.s->n;
343 	lastempty = 1;
344 
345   	switch (n) {
346   	case 0:					/* Global */
347   		do {
348 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
349 				/* Locate start of replaced string. */
350 				re_off = match[0].rm_so;
351 				/* Copy leading retained string. */
352 				cspace(&SS, s, re_off, APPEND);
353 				/* Add in regular expression. */
354 				regsub(&SS, s, cp->u.s->new);
355 			}
356 
357 			/* Move past this match. */
358 			if (match[0].rm_so != match[0].rm_eo) {
359 				s += match[0].rm_eo;
360 				slen -= match[0].rm_eo;
361 				lastempty = 0;
362 			} else if (match[0].rm_so == slen) {
363 				s += match[0].rm_so;
364 				slen = 0;
365 			} else {
366 				if (match[0].rm_so == 0)
367 					cspace(&SS, s, match[0].rm_so + 1,
368 					    APPEND);
369 				else
370 					cspace(&SS, s + match[0].rm_so, 1,
371 					    APPEND);
372 				s += match[0].rm_so + 1;
373 				slen -= match[0].rm_so + 1;
374 				lastempty = 1;
375 			}
376 		} while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
377 		/* Copy trailing retained string. */
378 		if (slen > 0)
379 			cspace(&SS, s, slen, APPEND);
380   		break;
381 	default:				/* Nth occurrence */
382 		while (--n) {
383 			s += match[0].rm_eo;
384 			slen -= match[0].rm_eo;
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