xref: /netbsd-src/usr.bin/sed/process.c (revision 811e6386f8c5e4a3521c7003da29ec8673e344fa)
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[] = "@(#)process.c	5.10 (Berkeley) 12/2/92";
40 #endif /* not lint */
41 
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #include <sys/ioctl.h>
45 #include <sys/uio.h>
46 
47 #include <ctype.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <limits.h>
51 #include <regex.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include "defs.h"
58 #include "extern.h"
59 
60 static SPACE HS, PS, SS;
61 #define	pd		PS.deleted
62 #define	ps		PS.space
63 #define	psl		PS.len
64 #define	hs		HS.space
65 #define	hsl		HS.len
66 
67 static inline int	 applies __P((struct s_command *));
68 static void		 flush_appends __P((void));
69 static void		 lputs __P((char *));
70 static inline int	 regexec_e __P((regex_t *, const char *, int, int));
71 static void		 regsub __P((SPACE *, char *, char *));
72 static int		 substitute __P((struct s_command *));
73 
74 struct s_appends *appends;	/* Array of pointers to strings to append. */
75 static int appendx;		/* Index into appends array. */
76 int appendnum;			/* Size of appends array. */
77 
78 static int lastaddr;		/* Set by applies if last address of a range. */
79 static int sdone;		/* If any substitutes since last line input. */
80 				/* Iov structure for 'w' commands. */
81 static struct iovec iov[2] = { NULL, 0, "\n", 1 };
82 
83 static regex_t *defpreg;
84 size_t maxnsub;
85 regmatch_t *match;
86 
87 void
88 process()
89 {
90 	struct s_command *cp;
91 	SPACE tspace;
92 	size_t len;
93 	int r;
94 	char oldc, *p;
95 
96 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
97 		pd = 0;
98 		cp = prog;
99 redirect:
100 		while (cp != NULL) {
101 			if (!applies(cp)) {
102 				cp = cp->next;
103 				continue;
104 			}
105 			switch (cp->code) {
106 			case '{':
107 				cp = cp->u.c;
108 				goto redirect;
109 			case 'a':
110 				if (appendx >= appendnum)
111 					appends = xrealloc(appends,
112 					    sizeof(struct s_appends) *
113 					    (appendnum *= 2));
114 				appends[appendx].type = AP_STRING;
115 				appends[appendx].s = cp->t;
116 				appendx++;
117 				break;
118 			case 'b':
119 				cp = cp->u.c;
120 				goto redirect;
121 			case 'c':
122 				pd = 1;
123 				psl = 0;
124 				if (cp->a2 == NULL || lastaddr)
125 					(void)printf("%s", cp->t);
126 				break;
127 			case 'd':
128 				pd = 1;
129 				goto new;
130 			case 'D':
131 				if (pd)
132 					goto new;
133 				if ((p = strchr(ps, '\n')) == NULL)
134 					pd = 1;
135 				else {
136 					psl -= (p - ps) - 1;
137 					memmove(ps, p + 1, psl);
138 				}
139 				goto new;
140 			case 'g':
141 				cspace(&PS, hs, hsl, REPLACE);
142 				break;
143 			case 'G':
144 				cspace(&PS, hs, hsl, APPENDNL);
145 				break;
146 			case 'h':
147 				cspace(&HS, ps, psl, REPLACE);
148 				break;
149 			case 'H':
150 				cspace(&HS, ps, psl, APPENDNL);
151 				break;
152 			case 'i':
153 				(void)printf("%s", cp->t);
154 				break;
155 			case 'l':
156 				lputs(ps);
157 				break;
158 			case 'n':
159 				if (!nflag && !pd)
160 					(void)printf("%s\n", ps);
161 				flush_appends();
162 				r = mf_fgets(&PS, REPLACE);
163 #ifdef HISTORIC_PRACTICE
164 				if (!r)
165 					exit(0);
166 #endif
167 				pd = 0;
168 				break;
169 			case 'N':
170 				flush_appends();
171 				if (!mf_fgets(&PS, APPENDNL)) {
172 					if (!nflag && !pd)
173 						(void)printf("%s\n", ps);
174 					exit(0);
175 				}
176 				break;
177 			case 'p':
178 				if (pd)
179 					break;
180 				(void)printf("%s\n", ps);
181 				break;
182 			case 'P':
183 				if (pd)
184 					break;
185 				if ((p = strchr(ps, '\n')) != NULL) {
186 					oldc = *p;
187 					*p = '\0';
188 				}
189 				(void)printf("%s\n", ps);
190 				if (p != NULL)
191 					*p = oldc;
192 				break;
193 			case 'q':
194 				if (!nflag && !pd)
195 					(void)printf("%s\n", 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 				appendx++;
206 				break;
207 			case 's':
208 				sdone |= substitute(cp);
209 				break;
210 			case 't':
211 				if (sdone) {
212 					sdone = 0;
213 					cp = cp->u.c;
214 					goto redirect;
215 				}
216 				break;
217 			case 'w':
218 				if (pd)
219 					break;
220 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
221 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
222 				    DEFFILEMODE)) == -1)
223 					err(FATAL, "%s: %s\n",
224 					    cp->t, strerror(errno));
225 				iov[0].iov_base = ps;
226 				iov[0].iov_len = psl;
227 				if (writev(cp->u.fd, iov, 2) != psl + 1)
228 					err(FATAL, "%s: %s\n",
229 					    cp->t, strerror(errno));
230 				break;
231 			case 'x':
232 				tspace = PS;
233 				PS = HS;
234 				HS = tspace;
235 				break;
236 			case 'y':
237 				if (pd)
238 					break;
239 				for (p = ps, len = psl; len--; ++p)
240 					*p = cp->u.y[*p];
241 				break;
242 			case ':':
243 			case '}':
244 				break;
245 			case '=':
246 				(void)printf("%lu\n", linenum);
247 			}
248 			cp = cp->next;
249 		} /* for all cp */
250 
251 new:		if (!nflag && !pd)
252 			(void)printf("%s\n", ps);
253 		flush_appends();
254 	} /* for all lines */
255 }
256 
257 /*
258  * TRUE if the address passed matches the current program state
259  * (lastline, linenumber, ps).
260  */
261 #define	MATCH(a)							\
262 	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1) :		\
263 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline
264 
265 /*
266  * Return TRUE if the command applies to the current line.  Sets the inrange
267  * flag to process ranges.  Interprets the non-select (``!'') flag.
268  */
269 static inline int
270 applies(cp)
271 	struct s_command *cp;
272 {
273 	int r;
274 
275 	lastaddr = 0;
276 	if (cp->a1 == NULL && cp->a2 == NULL)
277 		r = 1;
278 	else if (cp->a2)
279 		if (cp->inrange) {
280 			if (MATCH(cp->a2)) {
281 				cp->inrange = 0;
282 				lastaddr = 1;
283 			}
284 			r = 1;
285 		} else if (MATCH(cp->a1)) {
286 			/*
287 			 * If the second address is a number less than or
288 			 * equal to the line number first selected, only
289 			 * one line shall be selected.
290 			 *	-- POSIX 1003.2
291 			 */
292 			if (cp->a2->type == AT_LINE &&
293 			    linenum >= cp->a2->u.l)
294 				lastaddr = 1;
295 			else
296 				cp->inrange = 1;
297 			r = 1;
298 		} else
299 			r = 0;
300 	else
301 		r = MATCH(cp->a1);
302 	return (cp->nonsel ? ! r : r);
303 }
304 
305 /*
306  * substitute --
307  *	Do substitutions in the pattern space.  Currently, we build a
308  *	copy of the new pattern space in the substitute space structure
309  *	and then swap them.
310  */
311 static int
312 substitute(cp)
313 	struct s_command *cp;
314 {
315 	SPACE tspace;
316 	regex_t *re;
317 	size_t re_off;
318 	int n;
319 	char *s;
320 
321 	s = ps;
322 	re = cp->u.s->re;
323 	if (re == NULL) {
324 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
325 			linenum = cp->u.s->linenum;
326 			err(COMPILE, "\\%d not defined in the RE",
327 			    cp->u.s->maxbref);
328 		}
329 	}
330 	if (!regexec_e(re, s, 0, 0))
331 		return (0);
332 
333 	SS.len = 0;				/* Clean substitute space. */
334 	n = cp->u.s->n;
335 	switch (n) {
336 	case 0:					/* Global */
337 		do {
338 			/* Locate start of replaced string. */
339 			re_off = match[0].rm_so;
340 			/* Copy leading retained string. */
341 			cspace(&SS, s, re_off, APPEND);
342 			/* Add in regular expression. */
343 			regsub(&SS, s, cp->u.s->new);
344 			/* Move past this match. */
345 			s += match[0].rm_eo;
346 		} while(regexec_e(re, s, REG_NOTBOL, 0));
347 		/* Copy trailing retained string. */
348 		cspace(&SS, s, strlen(s), APPEND);
349 		break;
350 	default:				/* Nth occurrence */
351 		while (--n) {
352 			s += match[0].rm_eo;
353 			if (!regexec_e(re, s, REG_NOTBOL, 0))
354 				return (0);
355 		}
356 		/* FALLTHROUGH */
357 	case 1:					/* 1st occurrence */
358 		/* Locate start of replaced string. */
359 		re_off = match[0].rm_so + (s - ps);
360 		/* Copy leading retained string. */
361 		cspace(&SS, ps, re_off, APPEND);
362 		/* Add in regular expression. */
363 		regsub(&SS, s, cp->u.s->new);
364 		/* Copy trailing retained string. */
365 		s += match[0].rm_eo;
366 		cspace(&SS, s, strlen(s), APPEND);
367 		break;
368 	}
369 
370 	/*
371 	 * Swap the substitute space and the pattern space, and make sure
372 	 * that any leftover pointers into stdio memory get lost.
373 	 */
374 	tspace = PS;
375 	PS = SS;
376 	SS = tspace;
377 	SS.space = SS.back;
378 
379 	/* Handle the 'p' flag. */
380 	if (cp->u.s->p)
381 		(void)printf("%s\n", ps);
382 
383 	/* Handle the 'w' flag. */
384 	if (cp->u.s->wfile && !pd) {
385 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
386 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
387 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
388 		iov[0].iov_base = ps;
389 		iov[0].iov_len = psl;
390 		if (writev(cp->u.s->wfd, iov, 2) != psl + 1)
391 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
392 	}
393 	return (1);
394 }
395 
396 /*
397  * Flush append requests.  Always called before reading a line,
398  * therefore it also resets the substitution done (sdone) flag.
399  */
400 static void
401 flush_appends()
402 {
403 	FILE *f;
404 	int count, i;
405 	char buf[8 * 1024];
406 
407 	for (i = 0; i < appendx; i++)
408 		switch (appends[i].type) {
409 		case AP_STRING:
410 			(void)printf("%s", appends[i].s);
411 			break;
412 		case AP_FILE:
413 			/*
414 			 * Read files probably shouldn't be cached.  Since
415 			 * it's not an error to read a non-existent file,
416 			 * it's possible that another program is interacting
417 			 * with the sed script through the file system.  It
418 			 * would be truly bizarre, but possible.  It's probably
419 			 * not that big a performance win, anyhow.
420 			 */
421 			if ((f = fopen(appends[i].s, "r")) == NULL)
422 				break;
423 			while (count = fread(buf, 1, sizeof(buf), f))
424 				(void)fwrite(buf, 1, count, stdout);
425 			(void)fclose(f);
426 			break;
427 		}
428 	if (ferror(stdout))
429 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
430 	appendx = sdone = 0;
431 }
432 
433 static void
434 lputs(s)
435 	register char *s;
436 {
437 	register int count;
438 	register char *escapes, *p;
439 	struct winsize win;
440 	static int termwidth = -1;
441 
442 	if (termwidth == -1)
443 		if (p = getenv("COLUMNS"))
444 			termwidth = atoi(p);
445 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
446 		    win.ws_col > 0)
447 			termwidth = win.ws_col;
448 		else
449 			termwidth = 60;
450 
451 	for (count = 0; *s; ++s) {
452 		if (count >= termwidth) {
453 			(void)printf("\\\n");
454 			count = 0;
455 		}
456 		if (isascii(*s) && isprint(*s) && *s != '\\') {
457 			(void)putchar(*s);
458 			count++;
459 		} else {
460 			escapes = "\\\a\b\f\n\r\t\v";
461 			(void)putchar('\\');
462 			if (p = strchr(escapes, *s)) {
463 				(void)putchar("\\abfnrtv"[p - escapes]);
464 				count += 2;
465 			} else {
466 				(void)printf("%03o", (u_char)*s);
467 				count += 4;
468 			}
469 		}
470 	}
471 	(void)putchar('$');
472 	(void)putchar('\n');
473 	if (ferror(stdout))
474 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
475 }
476 
477 static inline int
478 regexec_e(preg, string, eflags, nomatch)
479 	regex_t *preg;
480 	const char *string;
481 	int eflags, nomatch;
482 {
483 	int eval;
484 
485 	if (preg == NULL) {
486 		if (defpreg == NULL)
487 			err(FATAL, "first RE may not be empty");
488 	} else
489 		defpreg = preg;
490 
491 	eval = regexec(defpreg, string,
492 	    nomatch ? 0 : maxnsub + 1, match, eflags);
493 	switch(eval) {
494 	case 0:
495 		return (1);
496 	case REG_NOMATCH:
497 		return (0);
498 	}
499 	err(FATAL, "RE error: %s", strregerror(eval, defpreg));
500 	/* NOTREACHED */
501 }
502 
503 /*
504  * regsub - perform substitutions after a regexp match
505  * Based on a routine by Henry Spencer
506  */
507 static void
508 regsub(sp, string, src)
509 	SPACE *sp;
510 	char *string, *src;
511 {
512 	register int len, no;
513 	register char c, *dst;
514 
515 #define	NEEDSP(reqlen)							\
516 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
517 		sp->blen += (reqlen) + 1024;				\
518 		sp->space = sp->back = xrealloc(sp->back, sp->blen);	\
519 		dst = sp->space + sp->len;				\
520 	}
521 
522 	dst = sp->space + sp->len;
523 	while ((c = *src++) != '\0') {
524 		if (c == '&')
525 			no = 0;
526 		else if (c == '\\' && isdigit(*src))
527 			no = *src++ - '0';
528 		else
529 			no = -1;
530 		if (no < 0) {		/* Ordinary character. */
531  			if (c == '\\' && (*src == '\\' || *src == '&'))
532  				c = *src++;
533 			NEEDSP(1);
534  			*dst++ = c;
535 			++sp->len;
536  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
537 			len = match[no].rm_eo - match[no].rm_so;
538 			NEEDSP(len);
539 			memmove(dst, string + match[no].rm_so, len);
540 			dst += len;
541 			sp->len += len;
542 		}
543 	}
544 	NEEDSP(1);
545 	*dst = '\0';
546 }
547 
548 /*
549  * aspace --
550  *	Append the source space to the destination space, allocating new
551  *	space as necessary.
552  */
553 void
554 cspace(sp, p, len, spflag)
555 	SPACE *sp;
556 	char *p;
557 	size_t len;
558 	enum e_spflag spflag;
559 {
560 	size_t tlen;
561 
562 	/*
563 	 * Make sure SPACE has enough memory and ramp up quickly.  Appends
564 	 * need two extra bytes, one for the newline, one for a terminating
565 	 * NULL.
566 	 */
567 	tlen = sp->len + len + spflag == APPENDNL ? 2 : 1;
568 	if (tlen > sp->blen) {
569 		sp->blen = tlen + 1024;
570 		sp->space = sp->back = xrealloc(sp->back, sp->blen);
571 	}
572 
573 	if (spflag == APPENDNL)
574 		sp->space[sp->len++] = '\n';
575 	else if (spflag == REPLACE)
576 		sp->len = 0;
577 
578 	memmove(sp->space + sp->len, p, len);
579 	sp->space[sp->len += len] = '\0';
580 }
581 
582 /*
583  * Close all cached opened files and report any errors
584  */
585 void
586 cfclose(cp, end)
587 	register struct s_command *cp, *end;
588 {
589 
590 	for (; cp != end; cp = cp->next)
591 		switch(cp->code) {
592 		case 's':
593 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
594 				err(FATAL,
595 				    "%s: %s", cp->u.s->wfile, strerror(errno));
596 			cp->u.s->wfd = -1;
597 			break;
598 		case 'w':
599 			if (cp->u.fd != -1 && close(cp->u.fd))
600 				err(FATAL, "%s: %s", cp->t, strerror(errno));
601 			cp->u.fd = -1;
602 			break;
603 		case '{':
604 			cfclose(cp->u.c, cp->next);
605 			break;
606 		}
607 }
608