xref: /netbsd-src/usr.bin/sed/process.c (revision 1f2744e6e4915c9da2a3f980279398c4cf7d5e6d)
1 /*-
2  * Copyright (c) 1992 Diomidis Spinellis.
3  * Copyright (c) 1992, 1993
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 /* from: static char sccsid[] = "@(#)process.c	8.1 (Berkeley) 6/6/93"; */
40 static char *rcsid = "$Id: process.c,v 1.16 1995/03/15 12:12:16 mycroft Exp $";
41 #endif /* not lint */
42 
43 #include <sys/types.h>
44 #include <sys/stat.h>
45 #include <sys/ioctl.h>
46 #include <sys/uio.h>
47 
48 #include <ctype.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <limits.h>
52 #include <regex.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 #include "defs.h"
59 #include "extern.h"
60 
61 static SPACE HS, PS, SS;
62 #define	pd		PS.deleted
63 #define	ps		PS.space
64 #define	psl		PS.len
65 #define	hs		HS.space
66 #define	hsl		HS.len
67 
68 static inline int	 applies __P((struct s_command *));
69 static void		 flush_appends __P((void));
70 static void		 lputs __P((char *));
71 static inline int	 regexec_e __P((regex_t *, const char *, int, int, size_t));
72 static void		 regsub __P((SPACE *, char *, char *));
73 static int		 substitute __P((struct s_command *));
74 
75 struct s_appends *appends;	/* Array of pointers to strings to append. */
76 static int appendx;		/* Index into appends array. */
77 int appendnum;			/* Size of appends array. */
78 
79 static int lastaddr;		/* Set by applies if last address of a range. */
80 static int sdone;		/* If any substitutes since last line input. */
81 				/* Iov structure for 'w' commands. */
82 static regex_t *defpreg;
83 size_t maxnsub;
84 regmatch_t *match;
85 
86 #define OUT(s) { fwrite(s, sizeof(u_char), psl, stdout); }
87 
88 void
89 process()
90 {
91 	struct s_command *cp;
92 	SPACE tspace;
93 	size_t len, oldpsl;
94 	char *p;
95 
96 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
97 		pd = 0;
98 top:
99 		cp = prog;
100 redirect:
101 		while (cp != NULL) {
102 			if (!applies(cp)) {
103 				cp = cp->next;
104 				continue;
105 			}
106 			switch (cp->code) {
107 			case '{':
108 				cp = cp->u.c;
109 				goto redirect;
110 			case 'a':
111 				if (appendx >= appendnum)
112 					appends = xrealloc(appends,
113 					    sizeof(struct s_appends) *
114 					    (appendnum *= 2));
115 				appends[appendx].type = AP_STRING;
116 				appends[appendx].s = cp->t;
117 				appends[appendx].len = strlen(cp->t);
118 				appendx++;
119 				break;
120 			case 'b':
121 				cp = cp->u.c;
122 				goto redirect;
123 			case 'c':
124 				pd = 1;
125 				psl = 0;
126 				if (cp->a2 == NULL || lastaddr)
127 					(void)printf("%s", cp->t);
128 				break;
129 			case 'd':
130 				pd = 1;
131 				goto new;
132 			case 'D':
133 				if (pd)
134 					goto new;
135 				if ((p = memchr(ps, '\n', psl - 1)) == NULL) {
136 					pd = 1;
137 					goto new;
138 				} else {
139 					psl -= (p + 1) - ps;
140 					memmove(ps, p + 1, psl);
141 					goto top;
142 				}
143 			case 'g':
144 				cspace(&PS, hs, hsl, REPLACE);
145 				break;
146 			case 'G':
147 				cspace(&PS, hs, hsl, 0);
148 				break;
149 			case 'h':
150 				cspace(&HS, ps, psl, REPLACE);
151 				break;
152 			case 'H':
153 				cspace(&HS, ps, psl, 0);
154 				break;
155 			case 'i':
156 				(void)printf("%s", cp->t);
157 				break;
158 			case 'l':
159 				lputs(ps);
160 				break;
161 			case 'n':
162 				if (!nflag && !pd)
163 					OUT(ps)
164 				flush_appends();
165 				if (!mf_fgets(&PS, REPLACE))
166 					exit(0);
167 				pd = 0;
168 				break;
169 			case 'N':
170 				flush_appends();
171 				if (!mf_fgets(&PS, 0)) {
172 					if (!nflag && !pd)
173 						OUT(ps)
174 					exit(0);
175 				}
176 				break;
177 			case 'p':
178 				if (pd)
179 					break;
180 				OUT(ps)
181 				break;
182 			case 'P':
183 				if (pd)
184 					break;
185 				if ((p = memchr(ps, '\n', psl - 1)) != NULL) {
186 					oldpsl = psl;
187 					psl = (p + 1) - ps;
188 				}
189 				OUT(ps)
190 				if (p != NULL)
191 					psl = oldpsl;
192 				break;
193 			case 'q':
194 				if (!nflag && !pd)
195 					OUT(ps)
196 				flush_appends();
197 				exit(0);
198 			case 'r':
199 				if (appendx >= appendnum)
200 					appends = xrealloc(appends,
201 					    sizeof(struct s_appends) *
202 					    (appendnum *= 2));
203 				appends[appendx].type = AP_FILE;
204 				appends[appendx].s = cp->t;
205 				appends[appendx].len = strlen(cp->t);
206 				appendx++;
207 				break;
208 			case 's':
209 				sdone |= substitute(cp);
210 				break;
211 			case 't':
212 				if (sdone) {
213 					sdone = 0;
214 					cp = cp->u.c;
215 					goto redirect;
216 				}
217 				break;
218 			case 'w':
219 				if (pd)
220 					break;
221 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
222 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
223 				    DEFFILEMODE)) == -1)
224 					err(FATAL, "%s: %s\n",
225 					    cp->t, strerror(errno));
226 				if (write(cp->u.fd, ps, psl) != psl)
227 					err(FATAL, "%s: %s\n",
228 					    cp->t, strerror(errno));
229 				break;
230 			case 'x':
231 				if (hs == NULL)
232 					cspace(&HS, "", 0, REPLACE);
233 				tspace = PS;
234 				PS = HS;
235 				HS = tspace;
236 				break;
237 			case 'y':
238 				if (pd)
239 					break;
240 				for (p = ps, len = psl; --len; ++p)
241 					*p = cp->u.y[*p];
242 				break;
243 			case ':':
244 			case '}':
245 				break;
246 			case '=':
247 				(void)printf("%lu\n", linenum);
248 			}
249 			cp = cp->next;
250 		} /* for all cp */
251 
252 new:		if (!nflag && !pd)
253 			OUT(ps)
254 		flush_appends();
255 	} /* for all lines */
256 }
257 
258 /*
259  * TRUE if the address passed matches the current program state
260  * (lastline, linenumber, ps).
261  */
262 #define	MATCH(a)						\
263 	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
264 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline
265 
266 /*
267  * Return TRUE if the command applies to the current line.  Sets the inrange
268  * flag to process ranges.  Interprets the non-select (``!'') flag.
269  */
270 static inline int
271 applies(cp)
272 	struct s_command *cp;
273 {
274 	int r;
275 
276 	lastaddr = 0;
277 	if (cp->a1 == NULL && cp->a2 == NULL)
278 		r = 1;
279 	else if (cp->a2)
280 		if (cp->inrange) {
281 			if (MATCH(cp->a2)) {
282 				cp->inrange = 0;
283 				lastaddr = 1;
284 			}
285 			r = 1;
286 		} else if (MATCH(cp->a1)) {
287 			/*
288 			 * If the second address is a number less than or
289 			 * equal to the line number first selected, only
290 			 * one line shall be selected.
291 			 *	-- POSIX 1003.2
292 			 */
293 			if (cp->a2->type == AT_LINE &&
294 			    linenum >= cp->a2->u.l)
295 				lastaddr = 1;
296 			else
297 				cp->inrange = 1;
298 			r = 1;
299 		} else
300 			r = 0;
301 	else
302 		r = MATCH(cp->a1);
303 	return (cp->nonsel ? ! r : r);
304 }
305 
306 /*
307  * substitute --
308  *	Do substitutions in the pattern space.  Currently, we build a
309  *	copy of the new pattern space in the substitute space structure
310  *	and then swap them.
311  */
312 static int
313 substitute(cp)
314 	struct s_command *cp;
315 {
316 	SPACE tspace;
317 	regex_t *re;
318 	size_t re_off, slen;
319 	int n, lastempty;
320 	char *s;
321 
322 	s = ps;
323 	re = cp->u.s->re;
324 	if (re == NULL) {
325 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
326 			linenum = cp->u.s->linenum;
327 			err(COMPILE, "\\%d not defined in the RE",
328 			    cp->u.s->maxbref);
329 		}
330 	}
331 	if (!regexec_e(re, s, 0, 0, psl))
332 		return (0);
333 
334 	SS.len = 0;				/* Clean substitute space. */
335 	slen = psl;
336 	n = cp->u.s->n;
337 	lastempty = 1;
338 
339 	switch (n) {
340 	case 0:					/* Global */
341 		do {
342 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
343 				/* Locate start of replaced string. */
344 				re_off = match[0].rm_so;
345 				/* Copy leading retained string. */
346 				cspace(&SS, s, re_off, APPEND);
347 				/* Add in regular expression. */
348 				regsub(&SS, s, cp->u.s->new);
349 			}
350 
351 			/* Move past this match. */
352 			if (match[0].rm_so != match[0].rm_eo) {
353 				s += match[0].rm_eo;
354 				slen -= match[0].rm_eo;
355 				lastempty = 0;
356 			} else {
357 				if (match[0].rm_so == 0)
358 					cspace(&SS, s, match[0].rm_so + 1,
359 					    APPEND);
360 				else
361 					cspace(&SS, s + match[0].rm_so, 1,
362 					    APPEND);
363 				s += match[0].rm_so + 1;
364 				slen -= match[0].rm_so + 1;
365 				lastempty = 1;
366 			}
367 		} while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
368 		/* Copy trailing retained string. */
369 		if (slen > 0)
370 			cspace(&SS, s, slen, APPEND);
371 		break;
372 	default:				/* Nth occurrence */
373 		while (--n) {
374 			s += match[0].rm_eo;
375 			slen -= match[0].rm_eo;
376 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
377 				return (0);
378 		}
379 		/* FALLTHROUGH */
380 	case 1:					/* 1st occurrence */
381 		/* Locate start of replaced string. */
382 		re_off = match[0].rm_so + (s - ps);
383 		/* Copy leading retained string. */
384 		cspace(&SS, ps, re_off, APPEND);
385 		/* Add in regular expression. */
386 		regsub(&SS, s, cp->u.s->new);
387 		/* Copy trailing retained string. */
388 		s += match[0].rm_eo;
389 		slen -= match[0].rm_eo;
390 		cspace(&SS, s, slen, APPEND);
391 		break;
392 	}
393 
394 	/*
395 	 * Swap the substitute space and the pattern space, and make sure
396 	 * that any leftover pointers into stdio memory get lost.
397 	 */
398 	tspace = PS;
399 	PS = SS;
400 	SS = tspace;
401 	SS.space = SS.back;
402 
403 	/* Handle the 'p' flag. */
404 	if (cp->u.s->p)
405 		OUT(ps)
406 
407 	/* Handle the 'w' flag. */
408 	if (cp->u.s->wfile && !pd) {
409 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
410 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
411 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
412 		if (write(cp->u.s->wfd, ps, psl) != psl)
413 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
414 	}
415 	return (1);
416 }
417 
418 /*
419  * Flush append requests.  Always called before reading a line,
420  * therefore it also resets the substitution done (sdone) flag.
421  */
422 static void
423 flush_appends()
424 {
425 	FILE *f;
426 	int count, i;
427 	char buf[8 * 1024];
428 
429 	for (i = 0; i < appendx; i++)
430 		switch (appends[i].type) {
431 		case AP_STRING:
432 			fwrite(appends[i].s, sizeof(char), appends[i].len,
433 			    stdout);
434 			break;
435 		case AP_FILE:
436 			/*
437 			 * Read files probably shouldn't be cached.  Since
438 			 * it's not an error to read a non-existent file,
439 			 * it's possible that another program is interacting
440 			 * with the sed script through the file system.  It
441 			 * would be truly bizarre, but possible.  It's probably
442 			 * not that big a performance win, anyhow.
443 			 */
444 			if ((f = fopen(appends[i].s, "r")) == NULL)
445 				break;
446 			while (count = fread(buf, sizeof(char), sizeof(buf), f))
447 				(void)fwrite(buf, sizeof(char), count, stdout);
448 			(void)fclose(f);
449 			break;
450 		}
451 	if (ferror(stdout))
452 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
453 	appendx = sdone = 0;
454 }
455 
456 static void
457 lputs(s)
458 	register char *s;
459 {
460 	register int count;
461 	register char *escapes, *p;
462 	struct winsize win;
463 	static int termwidth = -1;
464 
465 	if (termwidth == -1)
466 		if (p = getenv("COLUMNS"))
467 			termwidth = atoi(p);
468 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
469 		    win.ws_col > 0)
470 			termwidth = win.ws_col;
471 		else
472 			termwidth = 60;
473 
474 	for (count = 0; *s; ++s) {
475 		if (count >= termwidth) {
476 			(void)printf("\\\n");
477 			count = 0;
478 		}
479 		if (isascii(*s) && isprint(*s) && *s != '\\') {
480 			(void)putchar(*s);
481 			count++;
482 		} else {
483 			escapes = "\\\a\b\f\n\r\t\v";
484 			(void)putchar('\\');
485 			if (p = strchr(escapes, *s)) {
486 				(void)putchar("\\abfnrtv"[p - escapes]);
487 				count += 2;
488 			} else {
489 				(void)printf("%03o", *(u_char *)s);
490 				count += 4;
491 			}
492 		}
493 	}
494 	(void)putchar('$');
495 	(void)putchar('\n');
496 	if (ferror(stdout))
497 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
498 }
499 
500 static inline int
501 regexec_e(preg, string, eflags, nomatch, slen)
502 	regex_t *preg;
503 	const char *string;
504 	int eflags, nomatch;
505 	size_t slen;
506 {
507 	int eval;
508 
509 	if (preg == NULL) {
510 		if (defpreg == NULL)
511 			err(FATAL, "first RE may not be empty");
512 	} else
513 		defpreg = preg;
514 
515 	/* Set anchors, discounting trailing newline (if any). */
516 	if (slen > 0 && string[slen - 1] == '\n')
517 		slen--;
518 	match[0].rm_so = 0;
519 	match[0].rm_eo = slen;
520 
521 	eval = regexec(defpreg, string,
522 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
523 	switch(eval) {
524 	case 0:
525 		return (1);
526 	case REG_NOMATCH:
527 		return (0);
528 	}
529 	err(FATAL, "RE error: %s", strregerror(eval, defpreg));
530 	/* NOTREACHED */
531 }
532 
533 /*
534  * regsub - perform substitutions after a regexp match
535  * Based on a routine by Henry Spencer
536  */
537 static void
538 regsub(sp, string, src)
539 	SPACE *sp;
540 	char *string, *src;
541 {
542 	register int len, no;
543 	register char c, *dst;
544 
545 #define	NEEDSP(reqlen)							\
546 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
547 		sp->blen += (reqlen) + 1024;				\
548 		sp->space = sp->back = xrealloc(sp->back, sp->blen);	\
549 		dst = sp->space + sp->len;				\
550 	}
551 
552 	dst = sp->space + sp->len;
553 	while ((c = *src++) != '\0') {
554 		if (c == '&')
555 			no = 0;
556 		else if (c == '\\' && isdigit(*src))
557 			no = *src++ - '0';
558 		else
559 			no = -1;
560 		if (no < 0) {		/* Ordinary character. */
561  			if (c == '\\' && (*src == '\\' || *src == '&'))
562  				c = *src++;
563 			NEEDSP(1);
564  			*dst++ = c;
565 			++sp->len;
566  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
567 			len = match[no].rm_eo - match[no].rm_so;
568 			NEEDSP(len);
569 			memmove(dst, string + match[no].rm_so, len);
570 			dst += len;
571 			sp->len += len;
572 		}
573 	}
574 	NEEDSP(1);
575 	*dst = '\0';
576 }
577 
578 /*
579  * aspace --
580  *	Append the source space to the destination space, allocating new
581  *	space as necessary.
582  */
583 void
584 cspace(sp, p, len, spflag)
585 	SPACE *sp;
586 	char *p;
587 	size_t len;
588 	enum e_spflag spflag;
589 {
590 	size_t tlen;
591 
592 	/* Make sure SPACE has enough memory and ramp up quickly. */
593 	tlen = sp->len + len + 1;
594 	if (tlen > sp->blen) {
595 		sp->blen = tlen + 1024;
596 		sp->space = sp->back = xrealloc(sp->back, sp->blen);
597 	}
598 
599 	if (spflag == REPLACE)
600 		sp->len = 0;
601 
602 	memmove(sp->space + sp->len, p, len);
603 
604 	sp->space[sp->len += len] = '\0';
605 }
606 
607 /*
608  * Close all cached opened files and report any errors
609  */
610 void
611 cfclose(cp, end)
612 	register struct s_command *cp, *end;
613 {
614 
615 	for (; cp != end; cp = cp->next)
616 		switch(cp->code) {
617 		case 's':
618 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
619 				err(FATAL,
620 				    "%s: %s", cp->u.s->wfile, strerror(errno));
621 			cp->u.s->wfd = -1;
622 			break;
623 		case 'w':
624 			if (cp->u.fd != -1 && close(cp->u.fd))
625 				err(FATAL, "%s: %s", cp->t, strerror(errno));
626 			cp->u.fd = -1;
627 			break;
628 		case '{':
629 			cfclose(cp->u.c, cp->next);
630 			break;
631 		}
632 }
633