xref: /freebsd/usr.bin/sed/process.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
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;
93 	char oldc, *p;
94 
95 	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
96 		pd = 0;
97 		cp = prog;
98 redirect:
99 		while (cp != NULL) {
100 			if (!applies(cp)) {
101 				cp = cp->next;
102 				continue;
103 			}
104 			switch (cp->code) {
105 			case '{':
106 				cp = cp->u.c;
107 				goto redirect;
108 			case 'a':
109 				if (appendx >= appendnum)
110 					appends = xrealloc(appends,
111 					    sizeof(struct s_appends) *
112 					    (appendnum *= 2));
113 				appends[appendx].type = AP_STRING;
114 				appends[appendx].s = cp->t;
115 				appends[appendx].len = strlen(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 = memchr(ps, '\n', psl)) == 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, 0);
145 				break;
146 			case 'h':
147 				cspace(&HS, ps, psl, REPLACE);
148 				break;
149 			case 'H':
150 				cspace(&HS, ps, psl, 0);
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 					OUT(ps)
161 				flush_appends();
162 				if (!mf_fgets(&PS, REPLACE))
163 					exit(0);
164 				pd = 0;
165 				break;
166 			case 'N':
167 				flush_appends();
168 				if (!mf_fgets(&PS, 0)) {
169 					if (!nflag && !pd)
170 						OUT(ps)
171 					exit(0);
172 				}
173 				break;
174 			case 'p':
175 				if (pd)
176 					break;
177 				OUT(ps)
178 				break;
179 			case 'P':
180 				if (pd)
181 					break;
182 				if ((p = memchr(ps, '\n', psl)) != NULL) {
183 					oldc = *++p;
184 					*p = '\0';
185 				}
186 				OUT(ps)
187 				if (p != NULL)
188 					*p = oldc;
189 				break;
190 			case 'q':
191 				if (!nflag && !pd)
192 					OUT(ps)
193 				flush_appends();
194 				exit(0);
195 			case 'r':
196 				if (appendx >= appendnum)
197 					appends = xrealloc(appends,
198 					    sizeof(struct s_appends) *
199 					    (appendnum *= 2));
200 				appends[appendx].type = AP_FILE;
201 				appends[appendx].s = cp->t;
202 				appends[appendx].len = strlen(cp->t);
203 				appendx++;
204 				break;
205 			case 's':
206 				sdone |= substitute(cp);
207 				break;
208 			case 't':
209 				if (sdone) {
210 					sdone = 0;
211 					cp = cp->u.c;
212 					goto redirect;
213 				}
214 				break;
215 			case 'w':
216 				if (pd)
217 					break;
218 				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
219 				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
220 				    DEFFILEMODE)) == -1)
221 					err(FATAL, "%s: %s\n",
222 					    cp->t, strerror(errno));
223 				if (write(cp->u.fd, ps, psl) != psl)
224 					err(FATAL, "%s: %s\n",
225 					    cp->t, strerror(errno));
226 				break;
227 			case 'x':
228 				if (hs == NULL)
229 					cspace(&HS, "", 0, REPLACE);
230 				tspace = PS;
231 				PS = HS;
232 				HS = tspace;
233 				break;
234 			case 'y':
235 				if (pd)
236 					break;
237 				for (p = ps, len = psl; --len; ++p)
238 					*p = cp->u.y[*p];
239 				break;
240 			case ':':
241 			case '}':
242 				break;
243 			case '=':
244 				(void)printf("%lu\n", linenum);
245 			}
246 			cp = cp->next;
247 		} /* for all cp */
248 
249 new:		if (!nflag && !pd)
250 			OUT(ps)
251 		flush_appends();
252 	} /* for all lines */
253 }
254 
255 /*
256  * TRUE if the address passed matches the current program state
257  * (lastline, linenumber, ps).
258  */
259 #define	MATCH(a)						\
260 	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :	\
261 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline
262 
263 /*
264  * Return TRUE if the command applies to the current line.  Sets the inrange
265  * flag to process ranges.  Interprets the non-select (``!'') flag.
266  */
267 static inline int
268 applies(cp)
269 	struct s_command *cp;
270 {
271 	int r;
272 
273 	lastaddr = 0;
274 	if (cp->a1 == NULL && cp->a2 == NULL)
275 		r = 1;
276 	else if (cp->a2)
277 		if (cp->inrange) {
278 			if (MATCH(cp->a2)) {
279 				cp->inrange = 0;
280 				lastaddr = 1;
281 			}
282 			r = 1;
283 		} else if (MATCH(cp->a1)) {
284 			/*
285 			 * If the second address is a number less than or
286 			 * equal to the line number first selected, only
287 			 * one line shall be selected.
288 			 *	-- POSIX 1003.2
289 			 */
290 			if (cp->a2->type == AT_LINE &&
291 			    linenum >= cp->a2->u.l)
292 				lastaddr = 1;
293 			else
294 				cp->inrange = 1;
295 			r = 1;
296 		} else
297 			r = 0;
298 	else
299 		r = MATCH(cp->a1);
300 	return (cp->nonsel ? ! r : r);
301 }
302 
303 /*
304  * substitute --
305  *	Do substitutions in the pattern space.  Currently, we build a
306  *	copy of the new pattern space in the substitute space structure
307  *	and then swap them.
308  */
309 static int
310 substitute(cp)
311 	struct s_command *cp;
312 {
313 	SPACE tspace;
314 	regex_t *re;
315 	size_t re_off, slen;
316 	int lastempty, n;
317 	char *s;
318 
319 	s = ps;
320 	re = cp->u.s->re;
321 	if (re == NULL) {
322 		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
323 			linenum = cp->u.s->linenum;
324 			err(COMPILE, "\\%d not defined in the RE",
325 			    cp->u.s->maxbref);
326 		}
327 	}
328 	if (!regexec_e(re, s, 0, 0, psl))
329 		return (0);
330 
331   	SS.len = 0;				/* Clean substitute space. */
332   	slen = psl;
333   	n = cp->u.s->n;
334 	lastempty = 1;
335 
336   	switch (n) {
337   	case 0:					/* Global */
338   		do {
339 			if (lastempty || match[0].rm_so != match[0].rm_eo) {
340 				/* Locate start of replaced string. */
341 				re_off = match[0].rm_so;
342 				/* Copy leading retained string. */
343 				cspace(&SS, s, re_off, APPEND);
344 				/* Add in regular expression. */
345 				regsub(&SS, s, cp->u.s->new);
346 			}
347 
348   			/* Move past this match. */
349 			if (match[0].rm_so != match[0].rm_eo) {
350 				s += match[0].rm_eo;
351 				slen -= match[0].rm_eo;
352 				lastempty = 0;
353 			} else {
354 				if (match[0].rm_so == 0)
355 					cspace(&SS,
356 					    s, match[0].rm_so + 1, APPEND);
357 				else
358 					cspace(&SS,
359 					    s + match[0].rm_so, 1, APPEND);
360 				s += match[0].rm_so + 1;
361 				slen -= match[0].rm_so + 1;
362 				lastempty = 1;
363 			}
364 		} while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
365 		/* Copy trailing retained string. */
366 		if (slen > 0)
367 			cspace(&SS, s, slen, APPEND);
368   		break;
369 	default:				/* Nth occurrence */
370 		while (--n) {
371 			s += match[0].rm_eo;
372 			slen -= match[0].rm_eo;
373 			if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
374 				return (0);
375 		}
376 		/* FALLTHROUGH */
377 	case 1:					/* 1st occurrence */
378 		/* Locate start of replaced string. */
379 		re_off = match[0].rm_so + (s - ps);
380 		/* Copy leading retained string. */
381 		cspace(&SS, ps, re_off, APPEND);
382 		/* Add in regular expression. */
383 		regsub(&SS, s, cp->u.s->new);
384 		/* Copy trailing retained string. */
385 		s += match[0].rm_eo;
386 		slen -= match[0].rm_eo;
387 		cspace(&SS, s, slen, APPEND);
388 		break;
389 	}
390 
391 	/*
392 	 * Swap the substitute space and the pattern space, and make sure
393 	 * that any leftover pointers into stdio memory get lost.
394 	 */
395 	tspace = PS;
396 	PS = SS;
397 	SS = tspace;
398 	SS.space = SS.back;
399 
400 	/* Handle the 'p' flag. */
401 	if (cp->u.s->p)
402 		OUT(ps)
403 
404 	/* Handle the 'w' flag. */
405 	if (cp->u.s->wfile && !pd) {
406 		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
407 		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
408 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
409 		if (write(cp->u.s->wfd, ps, psl) != psl)
410 			err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
411 	}
412 	return (1);
413 }
414 
415 /*
416  * Flush append requests.  Always called before reading a line,
417  * therefore it also resets the substitution done (sdone) flag.
418  */
419 static void
420 flush_appends()
421 {
422 	FILE *f;
423 	int count, i;
424 	char buf[8 * 1024];
425 
426 	for (i = 0; i < appendx; i++)
427 		switch (appends[i].type) {
428 		case AP_STRING:
429 			fwrite(appends[i].s, sizeof(char), appends[i].len,
430 			    stdout);
431 			break;
432 		case AP_FILE:
433 			/*
434 			 * Read files probably shouldn't be cached.  Since
435 			 * it's not an error to read a non-existent file,
436 			 * it's possible that another program is interacting
437 			 * with the sed script through the file system.  It
438 			 * would be truly bizarre, but possible.  It's probably
439 			 * not that big a performance win, anyhow.
440 			 */
441 			if ((f = fopen(appends[i].s, "r")) == NULL)
442 				break;
443 			while (count = fread(buf, sizeof(char), sizeof(buf), f))
444 				(void)fwrite(buf, sizeof(char), count, stdout);
445 			(void)fclose(f);
446 			break;
447 		}
448 	if (ferror(stdout))
449 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
450 	appendx = sdone = 0;
451 }
452 
453 static void
454 lputs(s)
455 	register char *s;
456 {
457 	register int count;
458 	register char *escapes, *p;
459 	struct winsize win;
460 	static int termwidth = -1;
461 
462 	if (termwidth == -1)
463 		if (p = getenv("COLUMNS"))
464 			termwidth = atoi(p);
465 		else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
466 		    win.ws_col > 0)
467 			termwidth = win.ws_col;
468 		else
469 			termwidth = 60;
470 
471 	for (count = 0; *s; ++s) {
472 		if (count >= termwidth) {
473 			(void)printf("\\\n");
474 			count = 0;
475 		}
476 		if (isascii(*s) && isprint(*s) && *s != '\\') {
477 			(void)putchar(*s);
478 			count++;
479 		} else {
480 			escapes = "\\\a\b\f\n\r\t\v";
481 			(void)putchar('\\');
482 			if (p = strchr(escapes, *s)) {
483 				(void)putchar("\\abfnrtv"[p - escapes]);
484 				count += 2;
485 			} else {
486 				(void)printf("%03o", *(u_char *)s);
487 				count += 4;
488 			}
489 		}
490 	}
491 	(void)putchar('$');
492 	(void)putchar('\n');
493 	if (ferror(stdout))
494 		err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
495 }
496 
497 static inline int
498 regexec_e(preg, string, eflags, nomatch, slen)
499 	regex_t *preg;
500 	const char *string;
501 	int eflags, nomatch;
502 	size_t slen;
503 {
504 	int eval;
505 
506 	if (preg == NULL) {
507 		if (defpreg == NULL)
508 			err(FATAL, "first RE may not be empty");
509 	} else
510 		defpreg = preg;
511 
512 	/* Set anchors, discounting trailing newline (if any). */
513 	if (slen > 0 && string[slen - 1] == '\n')
514 		slen--;
515 	match[0].rm_so = 0;
516 	match[0].rm_eo = slen;
517 
518 	eval = regexec(defpreg, string,
519 	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
520 	switch(eval) {
521 	case 0:
522 		return (1);
523 	case REG_NOMATCH:
524 		return (0);
525 	}
526 	err(FATAL, "RE error: %s", strregerror(eval, defpreg));
527 	/* NOTREACHED */
528 }
529 
530 /*
531  * regsub - perform substitutions after a regexp match
532  * Based on a routine by Henry Spencer
533  */
534 static void
535 regsub(sp, string, src)
536 	SPACE *sp;
537 	char *string, *src;
538 {
539 	register int len, no;
540 	register char c, *dst;
541 
542 #define	NEEDSP(reqlen)							\
543 	if (sp->len >= sp->blen - (reqlen) - 1) {			\
544 		sp->blen += (reqlen) + 1024;				\
545 		sp->space = sp->back = xrealloc(sp->back, sp->blen);	\
546 		dst = sp->space + sp->len;				\
547 	}
548 
549 	dst = sp->space + sp->len;
550 	while ((c = *src++) != '\0') {
551 		if (c == '&')
552 			no = 0;
553 		else if (c == '\\' && isdigit(*src))
554 			no = *src++ - '0';
555 		else
556 			no = -1;
557 		if (no < 0) {		/* Ordinary character. */
558  			if (c == '\\' && (*src == '\\' || *src == '&'))
559  				c = *src++;
560 			NEEDSP(1);
561  			*dst++ = c;
562 			++sp->len;
563  		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
564 			len = match[no].rm_eo - match[no].rm_so;
565 			NEEDSP(len);
566 			memmove(dst, string + match[no].rm_so, len);
567 			dst += len;
568 			sp->len += len;
569 		}
570 	}
571 	NEEDSP(1);
572 	*dst = '\0';
573 }
574 
575 /*
576  * aspace --
577  *	Append the source space to the destination space, allocating new
578  *	space as necessary.
579  */
580 void
581 cspace(sp, p, len, spflag)
582 	SPACE *sp;
583 	char *p;
584 	size_t len;
585 	enum e_spflag spflag;
586 {
587 	size_t tlen;
588 
589 	/* Make sure SPACE has enough memory and ramp up quickly. */
590 	tlen = sp->len + len + 1;
591 	if (tlen > sp->blen) {
592 		sp->blen = tlen + 1024;
593 		sp->space = sp->back = xrealloc(sp->back, sp->blen);
594 	}
595 
596 	if (spflag == REPLACE)
597 		sp->len = 0;
598 
599 	memmove(sp->space + sp->len, p, len);
600 
601 	sp->space[sp->len += len] = '\0';
602 }
603 
604 /*
605  * Close all cached opened files and report any errors
606  */
607 void
608 cfclose(cp, end)
609 	register struct s_command *cp, *end;
610 {
611 
612 	for (; cp != end; cp = cp->next)
613 		switch(cp->code) {
614 		case 's':
615 			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
616 				err(FATAL,
617 				    "%s: %s", cp->u.s->wfile, strerror(errno));
618 			cp->u.s->wfd = -1;
619 			break;
620 		case 'w':
621 			if (cp->u.fd != -1 && close(cp->u.fd))
622 				err(FATAL, "%s: %s", cp->t, strerror(errno));
623 			cp->u.fd = -1;
624 			break;
625 		case '{':
626 			cfclose(cp->u.c, cp->next);
627 			break;
628 		}
629 }
630