xref: /freebsd/usr.bin/sed/process.c (revision 0b87f79976047c8f4332bbf7dc03146f6b0de79f)
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 - 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 				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 					if (!nflag && !pd)
181 						OUT(ps)
182 					exit(0);
183 				}
184 				break;
185 			case 'p':
186 				if (pd)
187 					break;
188 				OUT(ps)
189 				break;
190 			case 'P':
191 				if (pd)
192 					break;
193 				if (psl != 0 &&
194 				    (p = memchr(ps, '\n', psl - 1)) != NULL) {
195 					oldpsl = psl;
196 					psl = p - ps;
197 				}
198 				OUT(ps)
199 				if (p != NULL)
200 					psl = oldpsl;
201 				break;
202 			case 'q':
203 				if (!nflag && !pd)
204 					OUT(ps)
205 				flush_appends();
206 				exit(0);
207 			case 'r':
208 				if (appendx >= appendnum)
209 					if ((appends = realloc(appends,
210 					    sizeof(struct s_appends) *
211 					    (appendnum *= 2))) == NULL)
212 						err(1, "realloc");
213 				appends[appendx].type = AP_FILE;
214 				appends[appendx].s = cp->t;
215 				appends[appendx].len = strlen(cp->t);
216 				appendx++;
217 				break;
218 			case 's':
219 				sdone |= substitute(cp);
220 				break;
221 			case 't':
222 				if (sdone) {
223 					sdone = 0;
224 					cp = cp->u.c;
225 					goto redirect;
226 				}
227 				break;
228 			case 'w':
229 				if (pd)
230 					break;
231 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
232 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
233 				    DEFFILEMODE)) == -1)
234 					err(1, "%s", cp->t);
235 				if (write(cp->u.fd, ps, psl) != psl ||
236 				    write(cp->u.fd, "\n", 1) != 1)
237 					err(1, "%s", cp->t);
238 				break;
239 			case 'x':
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 				for (p = ps, len = psl; len--; ++p)
250 					*p = cp->u.y[(unsigned char)*p];
251 				break;
252 			case ':':
253 			case '}':
254 				break;
255 			case '=':
256 				(void)printf("%lu\n", linenum);
257 			}
258 			cp = cp->next;
259 		} /* for all cp */
260 
261 new:		if (!nflag && !pd)
262 			OUT(ps)
263 		flush_appends();
264 	} /* for all lines */
265 }
266 
267 /*
268  * TRUE if the address passed matches the current program state
269  * (lastline, linenumber, ps).
270  */
271 #define	MATCH(a)						\
272 	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
273 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline()
274 
275 /*
276  * Return TRUE if the command applies to the current line.  Sets the inrange
277  * flag to process ranges.  Interprets the non-select (``!'') flag.
278  */
279 static inline int
280 applies(cp)
281 	struct s_command *cp;
282 {
283 	int r;
284 
285 	lastaddr = 0;
286 	if (cp->a1 == NULL && cp->a2 == NULL)
287 		r = 1;
288 	else if (cp->a2)
289 		if (cp->inrange) {
290 			if (MATCH(cp->a2)) {
291 				cp->inrange = 0;
292 				lastaddr = 1;
293 			}
294 			r = 1;
295 		} else if (MATCH(cp->a1)) {
296 			/*
297 			 * If the second address is a number less than or
298 			 * equal to the line number first selected, only
299 			 * one line shall be selected.
300 			 *	-- POSIX 1003.2
301 			 */
302 			if (cp->a2->type == AT_LINE &&
303 			    linenum >= cp->a2->u.l)
304 				lastaddr = 1;
305 			else
306 				cp->inrange = 1;
307 			r = 1;
308 		} else
309 			r = 0;
310 	else
311 		r = MATCH(cp->a1);
312 	return (cp->nonsel ? ! r : r);
313 }
314 
315 /*
316  * substitute --
317  *	Do substitutions in the pattern space.  Currently, we build a
318  *	copy of the new pattern space in the substitute space structure
319  *	and then swap them.
320  */
321 static int
322 substitute(cp)
323 	struct s_command *cp;
324 {
325 	SPACE tspace;
326 	regex_t *re;
327 	size_t re_off, slen;
328 	int lastempty, n;
329 	char *s;
330 
331 	s = ps;
332 	re = cp->u.s->re;
333 	if (re == NULL) {
334 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
335 			linenum = cp->u.s->linenum;
336 			errx(1, "%lu: %s: \\%d not defined in the RE",
337 					linenum, fname, cp->u.s->maxbref);
338 		}
339 	}
340 	if (!regexec_e(re, s, 0, 0, psl))
341 		return (0);
342 
343   	SS.len = 0;				/* Clean substitute space. */
344   	slen = psl;
345   	n = cp->u.s->n;
346 	lastempty = 1;
347 
348   	switch (n) {
349   	case 0:					/* Global */
350   		do {
351 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
352 				/* Locate start of replaced string. */
353 				re_off = match[0].rm_so;
354 				/* Copy leading retained string. */
355 				cspace(&SS, s, re_off, APPEND);
356 				/* Add in regular expression. */
357 				regsub(&SS, s, cp->u.s->new);
358 			}
359 
360 			/* Move past this match. */
361 			if (match[0].rm_so != match[0].rm_eo) {
362 				s += match[0].rm_eo;
363 				slen -= match[0].rm_eo;
364 				lastempty = 0;
365 			} else if (match[0].rm_so == slen) {
366 				s += match[0].rm_so;
367 				slen = 0;
368 			} else {
369 				if (match[0].rm_so == 0)
370 					cspace(&SS, s, match[0].rm_so + 1,
371 					    APPEND);
372 				else
373 					cspace(&SS, s + match[0].rm_so, 1,
374 					    APPEND);
375 				s += match[0].rm_so + 1;
376 				slen -= match[0].rm_so + 1;
377 				lastempty = 1;
378 			}
379 		} while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
380 		/* Copy trailing retained string. */
381 		if (slen > 0)
382 			cspace(&SS, s, slen, APPEND);
383   		break;
384 	default:				/* Nth occurrence */
385 		while (--n) {
386 			s += match[0].rm_eo;
387 			slen -= match[0].rm_eo;
388 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
389 				return (0);
390 		}
391 		/* FALLTHROUGH */
392 	case 1:					/* 1st occurrence */
393 		/* Locate start of replaced string. */
394 		re_off = match[0].rm_so + (s - ps);
395 		/* Copy leading retained string. */
396 		cspace(&SS, ps, re_off, APPEND);
397 		/* Add in regular expression. */
398 		regsub(&SS, s, cp->u.s->new);
399 		/* Copy trailing retained string. */
400 		s += match[0].rm_eo;
401 		slen -= match[0].rm_eo;
402 		cspace(&SS, s, slen, APPEND);
403 		break;
404 	}
405 
406 	/*
407 	 * Swap the substitute space and the pattern space, and make sure
408 	 * that any leftover pointers into stdio memory get lost.
409 	 */
410 	tspace = PS;
411 	PS = SS;
412 	SS = tspace;
413 	SS.space = SS.back;
414 
415 	/* Handle the 'p' flag. */
416 	if (cp->u.s->p)
417 		OUT(ps)
418 
419 	/* Handle the 'w' flag. */
420 	if (cp->u.s->wfile && !pd) {
421 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
422 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
423 			err(1, "%s", cp->u.s->wfile);
424 		if (write(cp->u.s->wfd, ps, psl) != psl ||
425 		    write(cp->u.s->wfd, "\n", 1) != 1)
426 			err(1, "%s", cp->u.s->wfile);
427 	}
428 	return (1);
429 }
430 
431 /*
432  * Flush append requests.  Always called before reading a line,
433  * therefore it also resets the substitution done (sdone) flag.
434  */
435 static void
436 flush_appends()
437 {
438 	FILE *f;
439 	int count, i;
440 	char buf[8 * 1024];
441 
442 	for (i = 0; i < appendx; i++)
443 		switch (appends[i].type) {
444 		case AP_STRING:
445 			fwrite(appends[i].s, sizeof(char), appends[i].len,
446 			    stdout);
447 			break;
448 		case AP_FILE:
449 			/*
450 			 * Read files probably shouldn't be cached.  Since
451 			 * it's not an error to read a non-existent file,
452 			 * it's possible that another program is interacting
453 			 * with the sed script through the filesystem.  It
454 			 * would be truly bizarre, but possible.  It's probably
455 			 * not that big a performance win, anyhow.
456 			 */
457 			if ((f = fopen(appends[i].s, "r")) == NULL)
458 				break;
459 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
460 				(void)fwrite(buf, sizeof(char), count, stdout);
461 			(void)fclose(f);
462 			break;
463 		}
464 	if (ferror(stdout))
465 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
466 	appendx = sdone = 0;
467 }
468 
469 static void
470 lputs(s)
471 	char *s;
472 {
473 	int count;
474 	const char *escapes;
475 	char *p;
476 	struct winsize win;
477 	static int termwidth = -1;
478 
479 	if (termwidth == -1) {
480 		if ((p = getenv("COLUMNS")) && *p != '\0')
481 			termwidth = atoi(p);
482 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
483 		    win.ws_col > 0)
484 			termwidth = win.ws_col;
485 		else
486 			termwidth = 60;
487 	}
488 
489 	for (count = 0; *s; ++s) {
490 		if (count + 5 >= termwidth) {
491 			(void)printf("\\\n");
492 			count = 0;
493 		}
494 		if (isprint((unsigned char)*s) && *s != '\\') {
495 			(void)putchar(*s);
496 			count++;
497 		} else if (*s == '\n') {
498 			(void)putchar('$');
499 			(void)putchar('\n');
500 			count = 0;
501 		} else {
502 			escapes = "\\\a\b\f\r\t\v";
503 			(void)putchar('\\');
504 			if ((p = strchr(escapes, *s))) {
505 				(void)putchar("\\abfrtv"[p - escapes]);
506 				count += 2;
507 			} else {
508 				(void)printf("%03o", *(u_char *)s);
509 				count += 4;
510 			}
511 		}
512 	}
513 	(void)putchar('$');
514 	(void)putchar('\n');
515 	if (ferror(stdout))
516 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
517 }
518 
519 static inline int
520 regexec_e(preg, string, eflags, nomatch, slen)
521 	regex_t *preg;
522 	const char *string;
523 	int eflags, nomatch;
524 	size_t slen;
525 {
526 	int eval;
527 
528 	if (preg == NULL) {
529 		if (defpreg == NULL)
530 			errx(1, "first RE may not be empty");
531 	} else
532 		defpreg = preg;
533 
534 	/* Set anchors */
535 	match[0].rm_so = 0;
536 	match[0].rm_eo = slen;
537 
538 	eval = regexec(defpreg, string,
539 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
540 	switch(eval) {
541 	case 0:
542 		return (1);
543 	case REG_NOMATCH:
544 		return (0);
545 	}
546 	errx(1, "RE error: %s", strregerror(eval, defpreg));
547 	/* NOTREACHED */
548 }
549 
550 /*
551  * regsub - perform substitutions after a regexp match
552  * Based on a routine by Henry Spencer
553  */
554 static void
555 regsub(sp, string, src)
556 	SPACE *sp;
557 	char *string, *src;
558 {
559 	int len, no;
560 	char c, *dst;
561 
562 #define	NEEDSP(reqlen)							\
563 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
564 		sp->blen += (reqlen) + 1024;				\
565 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
566 		    == NULL)						\
567 			err(1, "realloc");				\
568 		dst = sp->space + sp->len;				\
569 	}
570 
571 	dst = sp->space + sp->len;
572 	while ((c = *src++) != '\0') {
573 		if (c == '&')
574 			no = 0;
575 		else if (c == '\\' && isdigit((unsigned char)*src))
576 			no = *src++ - '0';
577 		else
578 			no = -1;
579 		if (no < 0) {		/* Ordinary character. */
580  			if (c == '\\' && (*src == '\\' || *src == '&'))
581  				c = *src++;
582 			NEEDSP(1);
583  			*dst++ = c;
584 			++sp->len;
585  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
586 			len = match[no].rm_eo - match[no].rm_so;
587 			NEEDSP(len);
588 			memmove(dst, string + match[no].rm_so, len);
589 			dst += len;
590 			sp->len += len;
591 		}
592 	}
593 	NEEDSP(1);
594 	*dst = '\0';
595 }
596 
597 /*
598  * aspace --
599  *	Append the source space to the destination space, allocating new
600  *	space as necessary.
601  */
602 void
603 cspace(sp, p, len, spflag)
604 	SPACE *sp;
605 	const char *p;
606 	size_t len;
607 	enum e_spflag spflag;
608 {
609 	size_t tlen;
610 
611 	/* Make sure SPACE has enough memory and ramp up quickly. */
612 	tlen = sp->len + len + 1;
613 	if (tlen > sp->blen) {
614 		sp->blen = tlen + 1024;
615 		if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
616 		    NULL)
617 			err(1, "realloc");
618 	}
619 
620 	if (spflag == REPLACE)
621 		sp->len = 0;
622 
623 	memmove(sp->space + sp->len, p, len);
624 
625 	sp->space[sp->len += len] = '\0';
626 }
627 
628 /*
629  * Close all cached opened files and report any errors
630  */
631 void
632 cfclose(cp, end)
633 	struct s_command *cp, *end;
634 {
635 
636 	for (; cp != end; cp = cp->next)
637 		switch(cp->code) {
638 		case 's':
639 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
640 				err(1, "%s", cp->u.s->wfile);
641 			cp->u.s->wfd = -1;
642 			break;
643 		case 'w':
644 			if (cp->u.fd != -1 && close(cp->u.fd))
645 				err(1, "%s", cp->t);
646 			cp->u.fd = -1;
647 			break;
648 		case '{':
649 			cfclose(cp->u.c, cp->next);
650 			break;
651 		}
652 }
653