summaryrefslogtreecommitdiff
path: root/usr.bin/sed/process.c
blob: cc31fcb57a34a69cf897baf44ee6610dd40a43d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
/*	$OpenBSD: process.c,v 1.34 2018/11/14 10:59:33 martijn Exp $	*/

/*-
 * Copyright (c) 1992 Diomidis Spinellis.
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Diomidis Spinellis of Imperial College, University of London.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/uio.h>

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "defs.h"
#include "extern.h"

static SPACE HS, PS, SS;
#define	pd		PS.deleted
#define	ps		PS.space
#define	psl		PS.len
#define	psanl		PS.append_newline
#define	hs		HS.space
#define	hsl		HS.len

static inline int	 applies(struct s_command *);
static void		 flush_appends(void);
static void		 lputs(char *);
static inline int	 regexec_e(regex_t *, const char *, int, int, size_t,
			     size_t);
static void		 regsub(SPACE *, char *, char *);
static int		 substitute(struct s_command *);

struct s_appends *appends;	/* Array of pointers to strings to append. */
static size_t appendx;		/* Index into appends array. */
size_t appendnum;		/* Size of appends array. */

static int lastaddr;		/* Set by applies if last address of a range. */
static int sdone;		/* If any substitutes since last line input. */
				/* Iov structure for 'w' commands. */
static regex_t *defpreg;
size_t maxnsub;
regmatch_t *match;

#define OUT() do {\
	fwrite(ps, 1, psl, outfile);\
	if (psanl) fputc('\n', outfile);\
} while (0)

void
process(void)
{
	struct s_command *cp;
	SPACE tspace;
	size_t len, oldpsl;
	char *p;

	for (linenum = 0; mf_fgets(&PS, REPLACE);) {
		pd = 0;
top:
		cp = prog;
redirect:
		while (cp != NULL) {
			if (!applies(cp)) {
				cp = cp->next;
				continue;
			}
			switch (cp->code) {
			case '{':
				cp = cp->u.c;
				goto redirect;
			case 'a':
				if (appendx >= appendnum) {
					appends = xreallocarray(appends,
					    appendnum,
					    2 * sizeof(struct s_appends));
					appendnum *= 2;
				}
				appends[appendx].type = AP_STRING;
				appends[appendx].s = cp->t;
				appends[appendx].len = strlen(cp->t);
				appendx++;
				break;
			case 'b':
				cp = cp->u.c;
				goto redirect;
			case 'c':
				pd = 1;
				psl = 0;
				if (cp->a2 == NULL || lastaddr || lastline())
					(void)fprintf(outfile, "%s", cp->t);
				break;
			case 'd':
				pd = 1;
				goto new;
			case 'D':
				if (pd)
					goto new;
				if (psl == 0 ||
				    (p = memchr(ps, '\n', psl)) == NULL) {
					pd = 1;
					goto new;
				} else {
					psl -= (p + 1) - ps;
					memmove(ps, p + 1, psl);
					goto top;
				}
			case 'g':
				cspace(&PS, hs, hsl, REPLACE);
				break;
			case 'G':
				cspace(&PS, "\n", 1, 0);
				cspace(&PS, hs, hsl, 0);
				break;
			case 'h':
				cspace(&HS, ps, psl, REPLACE);
				break;
			case 'H':
				cspace(&HS, "\n", 1, 0);
				cspace(&HS, ps, psl, 0);
				break;
			case 'i':
				(void)fprintf(outfile, "%s", cp->t);
				break;
			case 'l':
				lputs(ps);
				break;
			case 'n':
				if (!nflag && !pd)
					OUT();
				flush_appends();
				if (!mf_fgets(&PS, REPLACE))
					exit(0);
				pd = 0;
				break;
			case 'N':
				flush_appends();
				cspace(&PS, "\n", 1, 0);
				if (!mf_fgets(&PS, 0))
					exit(0);
				break;
			case 'p':
				if (pd)
					break;
				OUT();
				break;
			case 'P':
				if (pd)
					break;
				if ((p = memchr(ps, '\n', psl)) != NULL) {
					oldpsl = psl;
					psl = p - ps;
					psanl = 1;
					OUT();
					psl = oldpsl;
				} else {
					OUT();
				}
				break;
			case 'q':
				if (!nflag && !pd)
					OUT();
				flush_appends();
				finish_file();
				exit(0);
			case 'r':
				if (appendx >= appendnum) {
					appends = xreallocarray(appends,
					    appendnum,
					    2 * sizeof(struct s_appends));
					appendnum *= 2;
				}
				appends[appendx].type = AP_FILE;
				appends[appendx].s = cp->t;
				appends[appendx].len = strlen(cp->t);
				appendx++;
				break;
			case 's':
				sdone |= substitute(cp);
				break;
			case 't':
				if (sdone) {
					sdone = 0;
					cp = cp->u.c;
					goto redirect;
				}
				break;
			case 'w':
				if (pd)
					break;
				if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
				    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
				    DEFFILEMODE)) == -1)
					error(FATAL, "%s: %s",
					    cp->t, strerror(errno));
				if ((size_t)write(cp->u.fd, ps, psl) != psl ||
				    write(cp->u.fd, "\n", 1) != 1)
					error(FATAL, "%s: %s",
					    cp->t, strerror(errno));
				break;
			case 'x':
				if (hs == NULL)
					cspace(&HS, "", 0, REPLACE);
				tspace = PS;
				PS = HS;
				psanl = tspace.append_newline;
				HS = tspace;
				break;
			case 'y':
				if (pd || psl == 0)
					break;
				for (p = ps, len = psl; len--; ++p)
					*p = cp->u.y[(unsigned char)*p];
				break;
			case ':':
			case '}':
				break;
			case '=':
				(void)fprintf(outfile, "%lu\n", linenum);
			}
			cp = cp->next;
		} /* for all cp */

new:		if (!nflag && !pd)
			OUT();
		flush_appends();
	} /* for all lines */
}

/*
 * TRUE if the address passed matches the current program state
 * (lastline, linenumber, ps).
 */
#define	MATCH(a)						\
	(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, 0, psl) :	\
	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline()

/*
 * Return TRUE if the command applies to the current line.  Sets the inrange
 * flag to process ranges.  Interprets the non-select (``!'') flag.
 */
static inline int
applies(struct s_command *cp)
{
	int r;

	lastaddr = 0;
	if (cp->a1 == NULL && cp->a2 == NULL)
		r = 1;
	else if (cp->a2)
		if (cp->inrange) {
			if (MATCH(cp->a2)) {
				cp->inrange = 0;
				lastaddr = 1;
			}
			r = 1;
		} else if (MATCH(cp->a1)) {
			/*
			 * If the second address is a number less than or
			 * equal to the line number first selected, only
			 * one line shall be selected.
			 *	-- POSIX 1003.2
			 */
			if (cp->a2->type == AT_LINE &&
			    linenum >= cp->a2->u.l)
				lastaddr = 1;
			else
				cp->inrange = 1;
			r = 1;
		} else
			r = 0;
	else
		r = MATCH(cp->a1);
	return (cp->nonsel ? !r : r);
}

/*
 * Reset all inrange markers.
 */
void
resetstate(void)
{
	struct s_command *cp;

	free(HS.back);
	memset(&HS, 0, sizeof(HS));

	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
		if (cp->a2)
			cp->inrange = 0;
}

/*
 * substitute --
 *	Do substitutions in the pattern space.  Currently, we build a
 *	copy of the new pattern space in the substitute space structure
 *	and then swap them.
 */
static int
substitute(struct s_command *cp)
{
	SPACE tspace;
	regex_t *re;
	regoff_t slen;
	int n, lastempty;
	regoff_t le = 0;
	char *s;

	s = ps;
	re = cp->u.s->re;
	if (re == NULL) {
		if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
			linenum = cp->u.s->linenum;
			error(COMPILE, "\\%d not defined in the RE",
			    cp->u.s->maxbref);
		}
	}
	if (!regexec_e(re, ps, 0, 0, 0, psl))
		return (0);

	SS.len = 0;				/* Clean substitute space. */
	slen = psl;
	n = cp->u.s->n;
	lastempty = 1;

	do {
		/* Copy the leading retained string. */
		if (n <= 1 && (match[0].rm_so > le))
			cspace(&SS, s, match[0].rm_so - le, APPEND);

		/* Skip zero-length matches right after other matches. */
		if (lastempty || (match[0].rm_so - le) ||
		    match[0].rm_so != match[0].rm_eo) {
			if (n <= 1) {
				/* Want this match: append replacement. */
				regsub(&SS, ps, cp->u.s->new);
				if (n == 1)
					n = -1;
			} else {
				/* Want a later match: append original. */
				if (match[0].rm_eo - le)
					cspace(&SS, s, match[0].rm_eo - le,
					    APPEND);
				n--;
			}
		}

		/* Move past this match. */
		s = ps + match[0].rm_eo;
		slen = psl - match[0].rm_eo;
		le = match[0].rm_eo;

		/*
		 * After a zero-length match, advance one byte,
		 * and at the end of the line, terminate.
		 */
		if (match[0].rm_so == match[0].rm_eo) {
			if (*s == '\0' || *s == '\n')
				slen = -1;
			else
				slen--;
			if (*s != '\0') {
				cspace(&SS, s++, 1, APPEND);
				le++;
			}
			lastempty = 1;
		} else
			lastempty = 0;

	} while (n >= 0 && slen >= 0 &&
	    regexec_e(re, ps, REG_NOTBOL, 0, le, psl));

	/* Did not find the requested number of matches. */
	if (n > 0)
		return (0);

	/* Copy the trailing retained string. */
	if (slen > 0)
		cspace(&SS, s, slen, APPEND);

	/*
	 * Swap the substitute space and the pattern space, and make sure
	 * that any leftover pointers into stdio memory get lost.
	 */
	tspace = PS;
	PS = SS;
	psanl = tspace.append_newline;
	SS = tspace;
	SS.space = SS.back;

	/* Handle the 'p' flag. */
	if (cp->u.s->p)
		OUT();

	/* Handle the 'w' flag. */
	if (cp->u.s->wfile && !pd) {
		if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
		    O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
			error(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno));
		if ((size_t)write(cp->u.s->wfd, ps, psl) != psl ||
		    write(cp->u.s->wfd, "\n", 1) != 1)
			error(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno));
	}
	return (1);
}

/*
 * Flush append requests.  Always called before reading a line,
 * therefore it also resets the substitution done (sdone) flag.
 */
static void
flush_appends(void)
{
	FILE *f;
	size_t count, idx;
	char buf[8 * 1024];

	for (idx = 0; idx < appendx; idx++)
		switch (appends[idx].type) {
		case AP_STRING:
			fwrite(appends[idx].s, sizeof(char), appends[idx].len,
			    outfile);
			break;
		case AP_FILE:
			/*
			 * Read files probably shouldn't be cached.  Since
			 * it's not an error to read a non-existent file,
			 * it's possible that another program is interacting
			 * with the sed script through the file system.  It
			 * would be truly bizarre, but possible.  It's probably
			 * not that big a performance win, anyhow.
			 */
			if ((f = fopen(appends[idx].s, "r")) == NULL)
				break;
			while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
				(void)fwrite(buf, sizeof(char), count, outfile);
			(void)fclose(f);
			break;
		}
	if (ferror(outfile))
		error(FATAL, "%s: %s", outfname, strerror(errno ? errno : EIO));
	appendx = sdone = 0;
}

static void
lputs(char *s)
{
	int count;
	extern int termwidth;
	const char *escapes;
	char *p;

	for (count = 0; *s; ++s) {
		if (count >= termwidth) {
			(void)fprintf(outfile, "\\\n");
			count = 0;
		}
		if (isascii((unsigned char)*s) && isprint((unsigned char)*s)
		    && *s != '\\') {
			(void)fputc(*s, outfile);
			count++;
		} else if (*s == '\n') {
			(void)fputc('$', outfile);
			(void)fputc('\n', outfile);
			count = 0;
		} else {
			escapes = "\\\a\b\f\r\t\v";
			(void)fputc('\\', outfile);
			if ((p = strchr(escapes, *s))) {
				(void)fputc("\\abfrtv"[p - escapes], outfile);
				count += 2;
			} else {
				(void)fprintf(outfile, "%03o", *(u_char *)s);
				count += 4;
			}
		}
	}
	(void)fputc('$', outfile);
	(void)fputc('\n', outfile);
	if (ferror(outfile))
		error(FATAL, "%s: %s", outfname, strerror(errno ? errno : EIO));
}

static inline int
regexec_e(regex_t *preg, const char *string, int eflags,
    int nomatch, size_t start, size_t stop)
{
	int eval;

	if (preg == NULL) {
		if (defpreg == NULL)
			error(FATAL, "first RE may not be empty");
	} else
		defpreg = preg;

	/* Set anchors */
	match[0].rm_so = start;
	match[0].rm_eo = stop;

	eval = regexec(defpreg, string,
	    nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
	switch (eval) {
	case 0:
		return (1);
	case REG_NOMATCH:
		return (0);
	}
	error(FATAL, "RE error: %s", strregerror(eval, defpreg));
}

/*
 * regsub - perform substitutions after a regexp match
 * Based on a routine by Henry Spencer
 */
static void
regsub(SPACE *sp, char *string, char *src)
{
	int len, no;
	char c, *dst;

#define	NEEDSP(reqlen)							\
	if (sp->len + (reqlen) + 1 >= sp->blen) {			\
		size_t newlen = sp->blen + (reqlen) + 1024;		\
		sp->space = sp->back = xrealloc(sp->back, newlen);	\
		sp->blen = newlen;					\
		dst = sp->space + sp->len;				\
	}

	dst = sp->space + sp->len;
	while ((c = *src++) != '\0') {
		if (c == '&')
			no = 0;
		else if (c == '\\' && isdigit((unsigned char)*src))
			no = *src++ - '0';
		else
			no = -1;
		if (no < 0) {		/* Ordinary character. */
			if (c == '\\' && (*src == '\\' || *src == '&'))
				c = *src++;
			NEEDSP(1);
			*dst++ = c;
			++sp->len;
		} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
			len = match[no].rm_eo - match[no].rm_so;
			NEEDSP(len);
			memmove(dst, string + match[no].rm_so, len);
			dst += len;
			sp->len += len;
		}
	}
	NEEDSP(1);
	*dst = '\0';
}

/*
 * aspace --
 *	Append the source space to the destination space, allocating new
 *	space as necessary.
 */
void
cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
{
	size_t tlen;

	/* Make sure SPACE has enough memory and ramp up quickly. */
	tlen = sp->len + len + 1;
	if (tlen > sp->blen) {
		size_t newlen = tlen + 1024;
		sp->space = sp->back = xrealloc(sp->back, newlen);
		sp->blen = newlen;
	}

	if (spflag == REPLACE)
		sp->len = 0;

	memmove(sp->space + sp->len, p, len);

	sp->space[sp->len += len] = '\0';
}

/*
 * Close all cached opened files and report any errors
 */
void
cfclose(struct s_command *cp, struct s_command *end)
{

	for (; cp != end; cp = cp->next)
		switch (cp->code) {
		case 's':
			if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
				error(FATAL,
				    "%s: %s", cp->u.s->wfile, strerror(errno));
			cp->u.s->wfd = -1;
			break;
		case 'w':
			if (cp->u.fd != -1 && close(cp->u.fd))
				error(FATAL, "%s: %s", cp->t, strerror(errno));
			cp->u.fd = -1;
			break;
		case '{':
			cfclose(cp->u.c, cp->next);
			break;
		}
}