xref: /freebsd/usr.bin/sed/process.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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 static char sccsid[] = "@(#)process.c	8.6 (Berkeley) 4/20/94";
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, size_t));
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 regex_t *defpreg;
82 size_t maxnsub;
83 regmatch_t *match;
84 
85 #define OUT(s) { fwrite(s, sizeof(u_char), psl, stdout); }
86 
87 void
88 process()
89 {
90 	struct s_command *cp;
91 	SPACE tspace;
92 	size_t len, oldpsl;
93 	char *p;
94 
95 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
96 		pd = 0;
97 top:
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 				appends[appendx].len = strlen(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 = memchr(ps, '\n', psl - 1)) == NULL) {
135 					pd = 1;
136 					goto new;
137 				} else {
138 					psl -= (p + 1) - ps;
139 					memmove(ps, p + 1, psl);
140 					goto top;
141 				}
142 			case 'g':
143 				cspace(&PS, hs, hsl, REPLACE);
144 				break;
145 			case 'G':
146 				cspace(&PS, hs, hsl, 0);
147 				break;
148 			case 'h':
149 				cspace(&HS, ps, psl, REPLACE);
150 				break;
151 			case 'H':
152 				cspace(&HS, ps, psl, 0);
153 				break;
154 			case 'i':
155 				(void)printf("%s", cp->t);
156 				break;
157 			case 'l':
158 				lputs(ps);
159 				break;
160 			case 'n':
161 				if (!nflag && !pd)
162 					OUT(ps)
163 				flush_appends();
164 				if (!mf_fgets(&PS, REPLACE))
165 					exit(0);
166 				pd = 0;
167 				break;
168 			case 'N':
169 				flush_appends();
170 				if (!mf_fgets(&PS, 0)) {
171 					if (!nflag && !pd)
172 						OUT(ps)
173 					exit(0);
174 				}
175 				break;
176 			case 'p':
177 				if (pd)
178 					break;
179 				OUT(ps)
180 				break;
181 			case 'P':
182 				if (pd)
183 					break;
184 				if ((p = memchr(ps, '\n', psl - 1)) != NULL) {
185 					oldpsl = psl;
186 					psl = (p + 1) - ps;
187 				}
188 				OUT(ps)
189 				if (p != NULL)
190 					psl = oldpsl;
191 				break;
192 			case 'q':
193 				if (!nflag && !pd)
194 					OUT(ps)
195 				flush_appends();
196 				exit(0);
197 			case 'r':
198 				if (appendx >= appendnum)
199 					appends = xrealloc(appends,
200 					    sizeof(struct s_appends) *
201 					    (appendnum *= 2));
202 				appends[appendx].type = AP_FILE;
203 				appends[appendx].s = cp->t;
204 				appends[appendx].len = strlen(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 				if (write(cp->u.fd, ps, psl) != psl)
226 					err(FATAL, "%s: %s\n",
227 					    cp->t, strerror(errno));
228 				break;
229 			case 'x':
230 				if (hs == NULL)
231 					cspace(&HS, "\n", 1, REPLACE);
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 			OUT(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, psl) :	\
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, slen;
318 	int lastempty, 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, psl))
331 		return (0);
332 
333   	SS.len = 0;				/* Clean substitute space. */
334   	slen = psl;
335   	n = cp->u.s->n;
336 	lastempty = 1;
337 
338   	switch (n) {
339   	case 0:					/* Global */
340   		do {
341 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
342 				/* Locate start of replaced string. */
343 				re_off = match[0].rm_so;
344 				/* Copy leading retained string. */
345 				cspace(&SS, s, re_off, APPEND);
346 				/* Add in regular expression. */
347 				regsub(&SS, s, cp->u.s->new);
348 			}
349 
350 			/* Move past this match. */
351 			if (match[0].rm_so != match[0].rm_eo) {
352 				s += match[0].rm_eo;
353 				slen -= match[0].rm_eo;
354 				lastempty = 0;
355 			} else {
356 				if (match[0].rm_so == 0)
357 					cspace(&SS, s, match[0].rm_so + 1,
358 					    APPEND);
359 				else
360 					cspace(&SS, s + match[0].rm_so, 1,
361 					    APPEND);
362 				s += match[0].rm_so + 1;
363 				slen -= match[0].rm_so + 1;
364 				lastempty = 1;
365 			}
366 		} while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
367 		/* Copy trailing retained string. */
368 		if (slen > 0)
369 			cspace(&SS, s, slen, APPEND);
370   		break;
371 	default:				/* Nth occurrence */
372 		while (--n) {
373 			s += match[0].rm_eo;
374 			slen -= match[0].rm_eo;
375 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
376 				return (0);
377 		}
378 		/* FALLTHROUGH */
379 	case 1:					/* 1st occurrence */
380 		/* Locate start of replaced string. */
381 		re_off = match[0].rm_so + (s - ps);
382 		/* Copy leading retained string. */
383 		cspace(&SS, ps, re_off, APPEND);
384 		/* Add in regular expression. */
385 		regsub(&SS, s, cp->u.s->new);
386 		/* Copy trailing retained string. */
387 		s += match[0].rm_eo;
388 		slen -= match[0].rm_eo;
389 		cspace(&SS, s, slen, APPEND);
390 		break;
391 	}
392 
393 	/*
394 	 * Swap the substitute space and the pattern space, and make sure
395 	 * that any leftover pointers into stdio memory get lost.
396 	 */
397 	tspace = PS;
398 	PS = SS;
399 	SS = tspace;
400 	SS.space = SS.back;
401 
402 	/* Handle the 'p' flag. */
403 	if (cp->u.s->p)
404 		OUT(ps)
405 
406 	/* Handle the 'w' flag. */
407 	if (cp->u.s->wfile && !pd) {
408 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
409 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
410 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
411 		if (write(cp->u.s->wfd, ps, psl) != psl)
412 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
413 	}
414 	return (1);
415 }
416 
417 /*
418  * Flush append requests.  Always called before reading a line,
419  * therefore it also resets the substitution done (sdone) flag.
420  */
421 static void
422 flush_appends()
423 {
424 	FILE *f;
425 	int count, i;
426 	char buf[8 * 1024];
427 
428 	for (i = 0; i < appendx; i++)
429 		switch (appends[i].type) {
430 		case AP_STRING:
431 			fwrite(appends[i].s, sizeof(char), appends[i].len,
432 			    stdout);
433 			break;
434 		case AP_FILE:
435 			/*
436 			 * Read files probably shouldn't be cached.  Since
437 			 * it's not an error to read a non-existent file,
438 			 * it's possible that another program is interacting
439 			 * with the sed script through the file system.  It
440 			 * would be truly bizarre, but possible.  It's probably
441 			 * not that big a performance win, anyhow.
442 			 */
443 			if ((f = fopen(appends[i].s, "r")) == NULL)
444 				break;
445 			while (count = fread(buf, sizeof(char), sizeof(buf), f))
446 				(void)fwrite(buf, sizeof(char), count, stdout);
447 			(void)fclose(f);
448 			break;
449 		}
450 	if (ferror(stdout))
451 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
452 	appendx = sdone = 0;
453 }
454 
455 static void
456 lputs(s)
457 	register char *s;
458 {
459 	register int count;
460 	register char *escapes, *p;
461 	struct winsize win;
462 	static int termwidth = -1;
463 
464 	if (termwidth == -1)
465 		if (p = getenv("COLUMNS"))
466 			termwidth = atoi(p);
467 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
468 		    win.ws_col > 0)
469 			termwidth = win.ws_col;
470 		else
471 			termwidth = 60;
472 
473 	for (count = 0; *s; ++s) {
474 		if (count >= termwidth) {
475 			(void)printf("\\\n");
476 			count = 0;
477 		}
478 		if (isprint((unsigned char)*s) && *s != '\\') {
479 			(void)putchar(*s);
480 			count++;
481 		} else {
482 			escapes = "\\\a\b\f\n\r\t\v";
483 			(void)putchar('\\');
484 			if (p = strchr(escapes, *s)) {
485 				(void)putchar("\\abfnrtv"[p - escapes]);
486 				count += 2;
487 			} else {
488 				(void)printf("%03o", *(u_char *)s);
489 				count += 4;
490 			}
491 		}
492 	}
493 	(void)putchar('$');
494 	(void)putchar('\n');
495 	if (ferror(stdout))
496 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
497 }
498 
499 static inline int
500 regexec_e(preg, string, eflags, nomatch, slen)
501 	regex_t *preg;
502 	const char *string;
503 	int eflags, nomatch;
504 	size_t slen;
505 {
506 	int eval;
507 
508 	if (preg == NULL) {
509 		if (defpreg == NULL)
510 			err(FATAL, "first RE may not be empty");
511 	} else
512 		defpreg = preg;
513 
514 	/* Set anchors, discounting trailing newline (if any). */
515 	if (slen > 0 && string[slen - 1] == '\n')
516 		slen--;
517 	match[0].rm_so = 0;
518 	match[0].rm_eo = slen;
519 
520 	eval = regexec(defpreg, string,
521 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
522 	switch(eval) {
523 	case 0:
524 		return (1);
525 	case REG_NOMATCH:
526 		return (0);
527 	}
528 	err(FATAL, "RE error: %s", strregerror(eval, defpreg));
529 	/* NOTREACHED */
530 }
531 
532 /*
533  * regsub - perform substitutions after a regexp match
534  * Based on a routine by Henry Spencer
535  */
536 static void
537 regsub(sp, string, src)
538 	SPACE *sp;
539 	char *string, *src;
540 {
541 	register int len, no;
542 	register char c, *dst;
543 
544 #define	NEEDSP(reqlen)							\
545 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
546 		sp->blen += (reqlen) + 1024;				\
547 		sp->space = sp->back = xrealloc(sp->back, sp->blen);	\
548 		dst = sp->space + sp->len;				\
549 	}
550 
551 	dst = sp->space + sp->len;
552 	while ((c = *src++) != '\0') {
553 		if (c == '&')
554 			no = 0;
555 		else if (c == '\\' && isdigit((unsigned char)*src))
556 			no = *src++ - '0';
557 		else
558 			no = -1;
559 		if (no < 0) {		/* Ordinary character. */
560  			if (c == '\\' && (*src == '\\' || *src == '&'))
561  				c = *src++;
562 			NEEDSP(1);
563  			*dst++ = c;
564 			++sp->len;
565  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
566 			len = match[no].rm_eo - match[no].rm_so;
567 			NEEDSP(len);
568 			memmove(dst, string + match[no].rm_so, len);
569 			dst += len;
570 			sp->len += len;
571 		}
572 	}
573 	NEEDSP(1);
574 	*dst = '\0';
575 }
576 
577 /*
578  * aspace --
579  *	Append the source space to the destination space, allocating new
580  *	space as necessary.
581  */
582 void
583 cspace(sp, p, len, spflag)
584 	SPACE *sp;
585 	char *p;
586 	size_t len;
587 	enum e_spflag spflag;
588 {
589 	size_t tlen;
590 
591 	/* Make sure SPACE has enough memory and ramp up quickly. */
592 	tlen = sp->len + len + 1;
593 	if (tlen > sp->blen) {
594 		sp->blen = tlen + 1024;
595 		sp->space = sp->back = xrealloc(sp->back, sp->blen);
596 	}
597 
598 	if (spflag == REPLACE)
599 		sp->len = 0;
600 
601 	memmove(sp->space + sp->len, p, len);
602 
603 	sp->space[sp->len += len] = '\0';
604 }
605 
606 /*
607  * Close all cached opened files and report any errors
608  */
609 void
610 cfclose(cp, end)
611 	register struct s_command *cp, *end;
612 {
613 
614 	for (; cp != end; cp = cp->next)
615 		switch(cp->code) {
616 		case 's':
617 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
618 				err(FATAL,
619 				    "%s: %s", cp->u.s->wfile, strerror(errno));
620 			cp->u.s->wfd = -1;
621 			break;
622 		case 'w':
623 			if (cp->u.fd != -1 && close(cp->u.fd))
624 				err(FATAL, "%s: %s", cp->t, strerror(errno));
625 			cp->u.fd = -1;
626 			break;
627 		case '{':
628 			cfclose(cp->u.c, cp->next);
629 			break;
630 		}
631 }
632