xref: /freebsd/usr.bin/sed/process.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)process.c	8.6 (Berkeley) 4/20/94";
41 #endif
42 static const char rcsid[] =
43   "$FreeBSD$";
44 #endif /* not lint */
45 
46 #include <sys/types.h>
47 #include <sys/stat.h>
48 #include <sys/ioctl.h>
49 #include <sys/uio.h>
50 
51 #include <ctype.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <limits.h>
56 #include <regex.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #include "defs.h"
63 #include "extern.h"
64 
65 static SPACE HS, PS, SS;
66 #define	pd		PS.deleted
67 #define	ps		PS.space
68 #define	psl		PS.len
69 #define	hs		HS.space
70 #define	hsl		HS.len
71 
72 static inline int	 applies __P((struct s_command *));
73 static void		 flush_appends __P((void));
74 static void		 lputs __P((char *));
75 static inline int	 regexec_e __P((regex_t *, const char *, int, int, size_t));
76 static void		 regsub __P((SPACE *, char *, char *));
77 static int		 substitute __P((struct s_command *));
78 
79 struct s_appends *appends;	/* Array of pointers to strings to append. */
80 static int appendx;		/* Index into appends array. */
81 int appendnum;			/* Size of appends array. */
82 
83 static int lastaddr;		/* Set by applies if last address of a range. */
84 static int sdone;		/* If any substitutes since last line input. */
85 				/* Iov structure for 'w' commands. */
86 static regex_t *defpreg;
87 size_t maxnsub;
88 regmatch_t *match;
89 
90 #define OUT(s) { fwrite(s, sizeof(u_char), psl, stdout); }
91 
92 void
93 process()
94 {
95 	struct s_command *cp;
96 	SPACE tspace;
97 	size_t len, oldpsl = 0;
98 	char *p;
99 
100 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
101 		pd = 0;
102 top:
103 		cp = prog;
104 redirect:
105 		while (cp != NULL) {
106 			if (!applies(cp)) {
107 				cp = cp->next;
108 				continue;
109 			}
110 			switch (cp->code) {
111 			case '{':
112 				cp = cp->u.c;
113 				goto redirect;
114 			case 'a':
115 				if (appendx >= appendnum)
116 					appends = xrealloc(appends,
117 					    sizeof(struct s_appends) *
118 					    (appendnum *= 2));
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 ((p = memchr(ps, '\n', psl - 1)) == NULL) {
140 					pd = 1;
141 					goto new;
142 				} else {
143 					psl -= (p + 1) - ps;
144 					memmove(ps, p + 1, psl);
145 					goto top;
146 				}
147 			case 'g':
148 				cspace(&PS, hs, hsl, REPLACE);
149 				break;
150 			case 'G':
151 				cspace(&PS, hs, hsl, 0);
152 				break;
153 			case 'h':
154 				cspace(&HS, ps, psl, REPLACE);
155 				break;
156 			case 'H':
157 				cspace(&HS, ps, psl, 0);
158 				break;
159 			case 'i':
160 				(void)printf("%s", cp->t);
161 				break;
162 			case 'l':
163 				lputs(ps);
164 				break;
165 			case 'n':
166 				if (!nflag && !pd)
167 					OUT(ps)
168 				flush_appends();
169 				if (!mf_fgets(&PS, REPLACE))
170 					exit(0);
171 				pd = 0;
172 				break;
173 			case 'N':
174 				flush_appends();
175 				if (!mf_fgets(&PS, 0)) {
176 					if (!nflag && !pd)
177 						OUT(ps)
178 					exit(0);
179 				}
180 				break;
181 			case 'p':
182 				if (pd)
183 					break;
184 				OUT(ps)
185 				break;
186 			case 'P':
187 				if (pd)
188 					break;
189 				if ((p = memchr(ps, '\n', psl - 1)) != NULL) {
190 					oldpsl = psl;
191 					psl = (p + 1) - ps;
192 				}
193 				OUT(ps)
194 				if (p != NULL)
195 					psl = oldpsl;
196 				break;
197 			case 'q':
198 				if (!nflag && !pd)
199 					OUT(ps)
200 				flush_appends();
201 				exit(0);
202 			case 'r':
203 				if (appendx >= appendnum)
204 					appends = xrealloc(appends,
205 					    sizeof(struct s_appends) *
206 					    (appendnum *= 2));
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) != psl)
230 					err(1, "%s", cp->t);
231 				break;
232 			case 'x':
233 				if (hs == NULL)
234 					cspace(&HS, "\n", 1, REPLACE);
235 				tspace = PS;
236 				PS = HS;
237 				HS = tspace;
238 				break;
239 			case 'y':
240 				if (pd)
241 					break;
242 				for (p = ps, len = psl; --len; ++p)
243 					*p = cp->u.y[(unsigned char)*p];
244 				break;
245 			case ':':
246 			case '}':
247 				break;
248 			case '=':
249 				(void)printf("%lu\n", linenum);
250 			}
251 			cp = cp->next;
252 		} /* for all cp */
253 
254 new:		if (!nflag && !pd)
255 			OUT(ps)
256 		flush_appends();
257 	} /* for all lines */
258 }
259 
260 /*
261  * TRUE if the address passed matches the current program state
262  * (lastline, linenumber, ps).
263  */
264 #define	MATCH(a)						\
265 	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
266 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline
267 
268 /*
269  * Return TRUE if the command applies to the current line.  Sets the inrange
270  * flag to process ranges.  Interprets the non-select (``!'') flag.
271  */
272 static inline int
273 applies(cp)
274 	struct s_command *cp;
275 {
276 	int r;
277 
278 	lastaddr = 0;
279 	if (cp->a1 == NULL && cp->a2 == NULL)
280 		r = 1;
281 	else if (cp->a2)
282 		if (cp->inrange) {
283 			if (MATCH(cp->a2)) {
284 				cp->inrange = 0;
285 				lastaddr = 1;
286 			}
287 			r = 1;
288 		} else if (MATCH(cp->a1)) {
289 			/*
290 			 * If the second address is a number less than or
291 			 * equal to the line number first selected, only
292 			 * one line shall be selected.
293 			 *	-- POSIX 1003.2
294 			 */
295 			if (cp->a2->type == AT_LINE &&
296 			    linenum >= cp->a2->u.l)
297 				lastaddr = 1;
298 			else
299 				cp->inrange = 1;
300 			r = 1;
301 		} else
302 			r = 0;
303 	else
304 		r = MATCH(cp->a1);
305 	return (cp->nonsel ? ! r : r);
306 }
307 
308 /*
309  * substitute --
310  *	Do substitutions in the pattern space.  Currently, we build a
311  *	copy of the new pattern space in the substitute space structure
312  *	and then swap them.
313  */
314 static int
315 substitute(cp)
316 	struct s_command *cp;
317 {
318 	SPACE tspace;
319 	regex_t *re;
320 	size_t re_off, slen;
321 	int lastempty, n;
322 	char *s;
323 
324 	s = ps;
325 	re = cp->u.s->re;
326 	if (re == NULL) {
327 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
328 			linenum = cp->u.s->linenum;
329 			errx(1, "%lu: %s: \\%d not defined in the RE",
330 					linenum, fname, cp->u.s->maxbref);
331 		}
332 	}
333 	if (!regexec_e(re, s, 0, 0, psl))
334 		return (0);
335 
336   	SS.len = 0;				/* Clean substitute space. */
337   	slen = psl;
338   	n = cp->u.s->n;
339 	lastempty = 1;
340 
341   	switch (n) {
342   	case 0:					/* Global */
343   		do {
344 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
345 				/* Locate start of replaced string. */
346 				re_off = match[0].rm_so;
347 				/* Copy leading retained string. */
348 				cspace(&SS, s, re_off, APPEND);
349 				/* Add in regular expression. */
350 				regsub(&SS, s, cp->u.s->new);
351 			}
352 
353 			/* Move past this match. */
354 			if (match[0].rm_so != match[0].rm_eo) {
355 				s += match[0].rm_eo;
356 				slen -= match[0].rm_eo;
357 				lastempty = 0;
358 			} else {
359 				if (match[0].rm_so == 0)
360 					cspace(&SS, s, match[0].rm_so + 1,
361 					    APPEND);
362 				else
363 					cspace(&SS, s + match[0].rm_so, 1,
364 					    APPEND);
365 				s += match[0].rm_so + 1;
366 				slen -= match[0].rm_so + 1;
367 				lastempty = 1;
368 			}
369 		} while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
370 		/* Copy trailing retained string. */
371 		if (slen > 0)
372 			cspace(&SS, s, slen, APPEND);
373   		break;
374 	default:				/* Nth occurrence */
375 		while (--n) {
376 			s += match[0].rm_eo;
377 			slen -= match[0].rm_eo;
378 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
379 				return (0);
380 		}
381 		/* FALLTHROUGH */
382 	case 1:					/* 1st occurrence */
383 		/* Locate start of replaced string. */
384 		re_off = match[0].rm_so + (s - ps);
385 		/* Copy leading retained string. */
386 		cspace(&SS, ps, re_off, APPEND);
387 		/* Add in regular expression. */
388 		regsub(&SS, s, cp->u.s->new);
389 		/* Copy trailing retained string. */
390 		s += match[0].rm_eo;
391 		slen -= match[0].rm_eo;
392 		cspace(&SS, s, slen, APPEND);
393 		break;
394 	}
395 
396 	/*
397 	 * Swap the substitute space and the pattern space, and make sure
398 	 * that any leftover pointers into stdio memory get lost.
399 	 */
400 	tspace = PS;
401 	PS = SS;
402 	SS = tspace;
403 	SS.space = SS.back;
404 
405 	/* Handle the 'p' flag. */
406 	if (cp->u.s->p)
407 		OUT(ps)
408 
409 	/* Handle the 'w' flag. */
410 	if (cp->u.s->wfile && !pd) {
411 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
412 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
413 			err(1, "%s", cp->u.s->wfile);
414 		if (write(cp->u.s->wfd, ps, psl) != psl)
415 			err(1, "%s", cp->u.s->wfile);
416 	}
417 	return (1);
418 }
419 
420 /*
421  * Flush append requests.  Always called before reading a line,
422  * therefore it also resets the substitution done (sdone) flag.
423  */
424 static void
425 flush_appends()
426 {
427 	FILE *f;
428 	int count, i;
429 	char buf[8 * 1024];
430 
431 	for (i = 0; i < appendx; i++)
432 		switch (appends[i].type) {
433 		case AP_STRING:
434 			fwrite(appends[i].s, sizeof(char), appends[i].len,
435 			    stdout);
436 			break;
437 		case AP_FILE:
438 			/*
439 			 * Read files probably shouldn't be cached.  Since
440 			 * it's not an error to read a non-existent file,
441 			 * it's possible that another program is interacting
442 			 * with the sed script through the file system.  It
443 			 * would be truly bizarre, but possible.  It's probably
444 			 * not that big a performance win, anyhow.
445 			 */
446 			if ((f = fopen(appends[i].s, "r")) == NULL)
447 				break;
448 			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
449 				(void)fwrite(buf, sizeof(char), count, stdout);
450 			(void)fclose(f);
451 			break;
452 		}
453 	if (ferror(stdout))
454 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
455 	appendx = sdone = 0;
456 }
457 
458 static void
459 lputs(s)
460 	register char *s;
461 {
462 	register int count;
463 	register char *escapes, *p;
464 	struct winsize win;
465 	static int termwidth = -1;
466 
467 	if (termwidth == -1) {
468 		if ((p = getenv("COLUMNS")))
469 			termwidth = atoi(p);
470 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
471 		    win.ws_col > 0)
472 			termwidth = win.ws_col;
473 		else
474 			termwidth = 60;
475 	}
476 
477 	for (count = 0; *s; ++s) {
478 		if (count >= termwidth) {
479 			(void)printf("\\\n");
480 			count = 0;
481 		}
482 		if (isprint((unsigned char)*s) && *s != '\\') {
483 			(void)putchar(*s);
484 			count++;
485 		} else {
486 			escapes = "\\\a\b\f\n\r\t\v";
487 			(void)putchar('\\');
488 			if ((p = strchr(escapes, *s))) {
489 				(void)putchar("\\abfnrtv"[p - escapes]);
490 				count += 2;
491 			} else {
492 				(void)printf("%03o", *(u_char *)s);
493 				count += 4;
494 			}
495 		}
496 	}
497 	(void)putchar('$');
498 	(void)putchar('\n');
499 	if (ferror(stdout))
500 		errx(1, "stdout: %s", strerror(errno ? errno : EIO));
501 }
502 
503 static inline int
504 regexec_e(preg, string, eflags, nomatch, slen)
505 	regex_t *preg;
506 	const char *string;
507 	int eflags, nomatch;
508 	size_t slen;
509 {
510 	int eval;
511 
512 	if (preg == NULL) {
513 		if (defpreg == NULL)
514 			errx(1, "first RE may not be empty");
515 	} else
516 		defpreg = preg;
517 
518 	/* Set anchors, discounting trailing newline (if any). */
519 	if (slen > 0 && string[slen - 1] == '\n')
520 		slen--;
521 	match[0].rm_so = 0;
522 	match[0].rm_eo = slen;
523 
524 	eval = regexec(defpreg, string,
525 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
526 	switch(eval) {
527 	case 0:
528 		return (1);
529 	case REG_NOMATCH:
530 		return (0);
531 	}
532 	errx(1, "RE error: %s", strregerror(eval, defpreg));
533 	/* NOTREACHED */
534 }
535 
536 /*
537  * regsub - perform substitutions after a regexp match
538  * Based on a routine by Henry Spencer
539  */
540 static void
541 regsub(sp, string, src)
542 	SPACE *sp;
543 	char *string, *src;
544 {
545 	register int len, no;
546 	register char c, *dst;
547 
548 #define	NEEDSP(reqlen)							\
549 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
550 		sp->blen += (reqlen) + 1024;				\
551 		sp->space = sp->back = xrealloc(sp->back, sp->blen);	\
552 		dst = sp->space + sp->len;				\
553 	}
554 
555 	dst = sp->space + sp->len;
556 	while ((c = *src++) != '\0') {
557 		if (c == '&')
558 			no = 0;
559 		else if (c == '\\' && isdigit((unsigned char)*src))
560 			no = *src++ - '0';
561 		else
562 			no = -1;
563 		if (no < 0) {		/* Ordinary character. */
564  			if (c == '\\' && (*src == '\\' || *src == '&'))
565  				c = *src++;
566 			NEEDSP(1);
567  			*dst++ = c;
568 			++sp->len;
569  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
570 			len = match[no].rm_eo - match[no].rm_so;
571 			NEEDSP(len);
572 			memmove(dst, string + match[no].rm_so, len);
573 			dst += len;
574 			sp->len += len;
575 		}
576 	}
577 	NEEDSP(1);
578 	*dst = '\0';
579 }
580 
581 /*
582  * aspace --
583  *	Append the source space to the destination space, allocating new
584  *	space as necessary.
585  */
586 void
587 cspace(sp, p, len, spflag)
588 	SPACE *sp;
589 	char *p;
590 	size_t len;
591 	enum e_spflag spflag;
592 {
593 	size_t tlen;
594 
595 	/* Make sure SPACE has enough memory and ramp up quickly. */
596 	tlen = sp->len + len + 1;
597 	if (tlen > sp->blen) {
598 		sp->blen = tlen + 1024;
599 		sp->space = sp->back = xrealloc(sp->back, sp->blen);
600 	}
601 
602 	if (spflag == REPLACE)
603 		sp->len = 0;
604 
605 	memmove(sp->space + sp->len, p, len);
606 
607 	sp->space[sp->len += len] = '\0';
608 }
609 
610 /*
611  * Close all cached opened files and report any errors
612  */
613 void
614 cfclose(cp, end)
615 	register struct s_command *cp, *end;
616 {
617 
618 	for (; cp != end; cp = cp->next)
619 		switch(cp->code) {
620 		case 's':
621 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
622 				err(1, "%s", cp->u.s->wfile);
623 			cp->u.s->wfd = -1;
624 			break;
625 		case 'w':
626 			if (cp->u.fd != -1 && close(cp->u.fd))
627 				err(1, "%s", cp->t);
628 			cp->u.fd = -1;
629 			break;
630 		case '{':
631 			cfclose(cp->u.c, cp->next);
632 			break;
633 		}
634 }
635