xref: /netbsd-src/usr.bin/sed/process.c (revision 4b30c543a0b21e3ba94f2c569e9a82b4fdb2075f)
1 /*-
2  * Copyright (c) 1992 Diomidis Spinellis.
3  * Copyright (c) 1992 The Regents of the University of California.
4  * 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 /*static char sccsid[] = "from: @(#)process.c	5.10 (Berkeley) 12/2/92";*/
40 static char rcsid[] = "$Id: process.c,v 1.7 1993/08/14 20:00:00 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));
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 struct iovec iov[2] = { NULL, 0, "\n", 1 };
83 
84 static regex_t *defpreg;
85 size_t maxnsub;
86 regmatch_t *match;
87 
88 void
89 process()
90 {
91 	struct s_command *cp;
92 	SPACE tspace;
93 	size_t len;
94 	int r;
95 	char oldc, *p;
96 
97 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
98 		pd = 0;
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 				appendx++;
118 				break;
119 			case 'b':
120 				cp = cp->u.c;
121 				goto redirect;
122 			case 'c':
123 				pd = 1;
124 				psl = 0;
125 				if (cp->a2 == NULL || lastaddr)
126 					(void)printf("%s", cp->t);
127 				break;
128 			case 'd':
129 				pd = 1;
130 				goto new;
131 			case 'D':
132 				if (pd)
133 					goto new;
134 				if ((p = strchr(ps, '\n')) == NULL)
135 					pd = 1;
136 				else {
137 					psl -= (p - ps) - 1;
138 					memmove(ps, p + 1, psl);
139 				}
140 				goto new;
141 			case 'g':
142 				cspace(&PS, hs, hsl, REPLACE);
143 				break;
144 			case 'G':
145 				cspace(&PS, hs, hsl, APPENDNL);
146 				break;
147 			case 'h':
148 				cspace(&HS, ps, psl, REPLACE);
149 				break;
150 			case 'H':
151 				cspace(&HS, ps, psl, APPENDNL);
152 				break;
153 			case 'i':
154 				(void)printf("%s", cp->t);
155 				break;
156 			case 'l':
157 				lputs(ps);
158 				break;
159 			case 'n':
160 				if (!nflag && !pd)
161 					(void)printf("%s\n", ps);
162 				flush_appends();
163 				r = mf_fgets(&PS, REPLACE);
164 #ifdef HISTORIC_PRACTICE
165 				if (!r)
166 					exit(0);
167 #endif
168 				pd = 0;
169 				break;
170 			case 'N':
171 				flush_appends();
172 				if (!mf_fgets(&PS, APPENDNL)) {
173 					if (!nflag && !pd)
174 						(void)printf("%s\n", ps);
175 					exit(0);
176 				}
177 				break;
178 			case 'p':
179 				if (pd)
180 					break;
181 				(void)printf("%s\n", ps);
182 				break;
183 			case 'P':
184 				if (pd)
185 					break;
186 				if ((p = strchr(ps, '\n')) != NULL) {
187 					oldc = *p;
188 					*p = '\0';
189 				}
190 				(void)printf("%s\n", ps);
191 				if (p != NULL)
192 					*p = oldc;
193 				break;
194 			case 'q':
195 				if (!nflag && !pd)
196 					(void)printf("%s\n", ps);
197 				flush_appends();
198 				exit(0);
199 			case 'r':
200 				if (appendx >= appendnum)
201 					appends = xrealloc(appends,
202 					    sizeof(struct s_appends) *
203 					    (appendnum *= 2));
204 				appends[appendx].type = AP_FILE;
205 				appends[appendx].s = 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 				iov[0].iov_base = ps;
227 				iov[0].iov_len = psl;
228 				if (writev(cp->u.fd, iov, 2) != psl + 1)
229 					err(FATAL, "%s: %s\n",
230 					    cp->t, strerror(errno));
231 				break;
232 			case 'x':
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 			(void)printf("%s\n", 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) :		\
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;
319 	size_t re_eoff;
320 	int n;
321 	char *s;
322 	char *eos;
323 
324 	s = ps;
325 	eos = s + strlen(s);
326 	re = cp->u.s->re;
327 	if (re == NULL) {
328 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
329 			linenum = cp->u.s->linenum;
330 			err(COMPILE, "\\%d not defined in the RE",
331 			    cp->u.s->maxbref);
332 		}
333 	}
334 	if (!regexec_e(re, s, 0, 0))
335 		return (0);
336 
337 	SS.len = 0;				/* Clean substitute space. */
338 	n = cp->u.s->n;
339 	switch (n) {
340 	case 0:					/* Global */
341 		do {
342 			/* Locate start of replaced string. */
343 			re_off = match[0].rm_so;
344 			re_eoff = match[0].rm_eo;
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 			/* Move past this match. */
350 			s += match[0].rm_eo;
351 		} while(*s && re_eoff && regexec_e(re, s, REG_NOTBOL, 0));
352 		if (eos - s > 0 && !re_eoff)
353 			err(FATAL, "infinite substitution loop");
354 		/* Copy trailing retained string. */
355 		cspace(&SS, s, strlen(s), APPEND);
356 		break;
357 	default:				/* Nth occurrence */
358 		while (--n) {
359 			s += match[0].rm_eo;
360 			if (!regexec_e(re, s, REG_NOTBOL, 0))
361 				return (0);
362 		}
363 		/* FALLTHROUGH */
364 	case 1:					/* 1st occurrence */
365 		/* Locate start of replaced string. */
366 		re_off = match[0].rm_so + (s - ps);
367 		/* Copy leading retained string. */
368 		cspace(&SS, ps, re_off, APPEND);
369 		/* Add in regular expression. */
370 		regsub(&SS, s, cp->u.s->new);
371 		/* Copy trailing retained string. */
372 		s += match[0].rm_eo;
373 		cspace(&SS, s, strlen(s), APPEND);
374 		break;
375 	}
376 
377 	/*
378 	 * Swap the substitute space and the pattern space, and make sure
379 	 * that any leftover pointers into stdio memory get lost.
380 	 */
381 	tspace = PS;
382 	PS = SS;
383 	SS = tspace;
384 	SS.space = SS.back;
385 
386 	/* Handle the 'p' flag. */
387 	if (cp->u.s->p)
388 		(void)printf("%s\n", ps);
389 
390 	/* Handle the 'w' flag. */
391 	if (cp->u.s->wfile && !pd) {
392 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
393 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
394 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
395 		iov[0].iov_base = ps;
396 		iov[0].iov_len = psl;
397 		if (writev(cp->u.s->wfd, iov, 2) != psl + 1)
398 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
399 	}
400 	return (1);
401 }
402 
403 /*
404  * Flush append requests.  Always called before reading a line,
405  * therefore it also resets the substitution done (sdone) flag.
406  */
407 static void
408 flush_appends()
409 {
410 	FILE *f;
411 	int count, i;
412 	char buf[8 * 1024];
413 
414 	for (i = 0; i < appendx; i++)
415 		switch (appends[i].type) {
416 		case AP_STRING:
417 			(void)printf("%s", appends[i].s);
418 			break;
419 		case AP_FILE:
420 			/*
421 			 * Read files probably shouldn't be cached.  Since
422 			 * it's not an error to read a non-existent file,
423 			 * it's possible that another program is interacting
424 			 * with the sed script through the file system.  It
425 			 * would be truly bizarre, but possible.  It's probably
426 			 * not that big a performance win, anyhow.
427 			 */
428 			if ((f = fopen(appends[i].s, "r")) == NULL)
429 				break;
430 			while (count = fread(buf, 1, sizeof(buf), f))
431 				(void)fwrite(buf, 1, count, stdout);
432 			(void)fclose(f);
433 			break;
434 		}
435 	if (ferror(stdout))
436 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
437 	appendx = sdone = 0;
438 }
439 
440 static void
441 lputs(s)
442 	register char *s;
443 {
444 	register int count;
445 	register char *escapes, *p;
446 	struct winsize win;
447 	static int termwidth = -1;
448 
449 	if (termwidth == -1)
450 		if (p = getenv("COLUMNS"))
451 			termwidth = atoi(p);
452 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
453 		    win.ws_col > 0)
454 			termwidth = win.ws_col;
455 		else
456 			termwidth = 60;
457 
458 	for (count = 0; *s; ++s) {
459 		if (count >= termwidth) {
460 			(void)printf("\\\n");
461 			count = 0;
462 		}
463 		if (isascii(*s) && isprint(*s) && *s != '\\') {
464 			(void)putchar(*s);
465 			count++;
466 		} else {
467 			escapes = "\\\a\b\f\n\r\t\v";
468 			(void)putchar('\\');
469 			if (p = strchr(escapes, *s)) {
470 				(void)putchar("\\abfnrtv"[p - escapes]);
471 				count += 2;
472 			} else {
473 				(void)printf("%03o", (u_char)*s);
474 				count += 4;
475 			}
476 		}
477 	}
478 	(void)putchar('$');
479 	(void)putchar('\n');
480 	if (ferror(stdout))
481 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
482 }
483 
484 static inline int
485 regexec_e(preg, string, eflags, nomatch)
486 	regex_t *preg;
487 	const char *string;
488 	int eflags, nomatch;
489 {
490 	int eval;
491 
492 	if (preg == NULL) {
493 		if (defpreg == NULL)
494 			err(FATAL, "first RE may not be empty");
495 	} else
496 		defpreg = preg;
497 
498 	eval = regexec(defpreg, string,
499 	    nomatch ? 0 : maxnsub + 1, match, eflags);
500 	switch(eval) {
501 	case 0:
502 		return (1);
503 	case REG_NOMATCH:
504 		return (0);
505 	}
506 	err(FATAL, "RE error: %s", strregerror(eval, defpreg));
507 	/* NOTREACHED */
508 }
509 
510 /*
511  * regsub - perform substitutions after a regexp match
512  * Based on a routine by Henry Spencer
513  */
514 static void
515 regsub(sp, string, src)
516 	SPACE *sp;
517 	char *string, *src;
518 {
519 	register int len, no;
520 	register char c, *dst;
521 
522 #define	NEEDSP(reqlen)							\
523 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
524 		sp->blen += (reqlen) + 1024;				\
525 		sp->space = sp->back = xrealloc(sp->back, sp->blen);	\
526 		dst = sp->space + sp->len;				\
527 	}
528 
529 	dst = sp->space + sp->len;
530 	while ((c = *src++) != '\0') {
531 		if (c == '&')
532 			no = 0;
533 		else if (c == '\\' && isdigit(*src))
534 			no = *src++ - '0';
535 		else
536 			no = -1;
537 		if (no < 0) {		/* Ordinary character. */
538  			if (c == '\\' && (*src == '\\' || *src == '&'))
539  				c = *src++;
540 			NEEDSP(1);
541  			*dst++ = c;
542 			++sp->len;
543  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
544 			len = match[no].rm_eo - match[no].rm_so;
545 			NEEDSP(len);
546 			memmove(dst, string + match[no].rm_so, len);
547 			dst += len;
548 			sp->len += len;
549 		}
550 	}
551 	NEEDSP(1);
552 	*dst = '\0';
553 }
554 
555 /*
556  * aspace --
557  *	Append the source space to the destination space, allocating new
558  *	space as necessary.
559  */
560 void
561 cspace(sp, p, len, spflag)
562 	SPACE *sp;
563 	char *p;
564 	size_t len;
565 	enum e_spflag spflag;
566 {
567 	size_t tlen;
568 
569 	/*
570 	 * Make sure SPACE has enough memory and ramp up quickly.  Appends
571 	 * need two extra bytes, one for the newline, one for a terminating
572 	 * NULL.
573 	 */
574 /*	tlen = sp->len + len + spflag == APPENDNL ? 2 : 1; */
575 	tlen = sp->len + len + (spflag == APPENDNL ? 2 : 1);  /* XXX */
576 	if (tlen > sp->blen) {
577 		sp->blen = tlen + 1024;
578 		sp->space = sp->back = xrealloc(sp->back, sp->blen);
579 	}
580 
581 	if (spflag == APPENDNL)
582 		sp->space[sp->len++] = '\n';
583 	else if (spflag == REPLACE)
584 		sp->len = 0;
585 
586 	memmove(sp->space + sp->len, p, len);
587 	sp->space[sp->len += len] = '\0';
588 }
589 
590 /*
591  * Close all cached opened files and report any errors
592  */
593 void
594 cfclose(cp, end)
595 	register struct s_command *cp, *end;
596 {
597 
598 	for (; cp != end; cp = cp->next)
599 		switch(cp->code) {
600 		case 's':
601 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
602 				err(FATAL,
603 				    "%s: %s", cp->u.s->wfile, strerror(errno));
604 			cp->u.s->wfd = -1;
605 			break;
606 		case 'w':
607 			if (cp->u.fd != -1 && close(cp->u.fd))
608 				err(FATAL, "%s: %s", cp->t, strerror(errno));
609 			cp->u.fd = -1;
610 			break;
611 		case '{':
612 			cfclose(cp->u.c, cp->next);
613 			break;
614 		}
615 }
616