File: s_regex.c

package info (click to toggle)
super 3.30.0-3+squeeze2
  • links: PTS
  • area: main
  • in suites: squeeze
  • size: 1,088 kB
  • ctags: 755
  • sloc: ansic: 10,089; sh: 288; makefile: 201
file content (875 lines) | stat: -rw-r--r-- 19,083 bytes parent folder | download | duplicates (7)
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
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
static const char rcsid[] = "$Id: s_regex.c,v 1.10 2004/04/30 17:00:58 will Exp $";
/*
 * regex - Regular expression pattern matching
 *         and replacement
 *
 *
 * By:  Ozan S. Yigit (oz)
 *      Dept. of Computer Science
 *      York University
 *
 *
 * These routines are the PUBLIC DOMAIN equivalents 
 * of regex routines as found in 4.nBSD UN*X, with minor
 * extensions.
 *
 * These routines are derived from various implementations
 * found in software tools books, and Conroy's grep. They
 * are NOT derived from licensed/restricted software.
 * For more interesting/academic/complicated implementations,
 * see Henry Spencer's regexp routines, or GNU Emacs pattern
 * matching module.
 *
 * ** NAMES CHANGED TO BE PREFIXED WITH s_, TO AVOID CONFLICTS **
 * ** -Will Deich, Feb 1997 **
 *
 * Routines:
 *      s_re_comp:      compile a regular expression into
 *                      a DFA.
 *
 *			char *s_re_comp(s)
 *			char *s;
 *
 *      s_re_exec:      execute the DFA to match a pattern.
 *
 *			int s_re_exec(s)
 *			char *s;
 *
 *	s_re_modw	change s_re_exec's understanding of what
 *			a "word" looks like (for \< and \>)
 *			by adding into the hidden word-character 
 *			table.
 *
 *			void s_re_modw(s)
 *			char *s;
 *
 *      s_re_subs:	substitute the matched portions in
 *              	a new string.
 *
 *			int s_re_subs(src, dst)
 *			char *src;
 *			char *dst;
 *
 *	s_re_fail:	failure routine for s_re_exec.
 *
 *			void s_re_fail(msg, op)
 *			char *msg;
 *			char op;
 *  
 * Regular Expressions:
 *
 *      [1]     char    matches itself, unless it is a special
 *                      character (metachar): . \ [ ] * + ^ $
 *
 *      [2]     .       matches any character.
 *
 *      [3]     \       matches the character following it, except
 *			when followed by a left or right round bracket,
 *			a digit 1 to 9 or a left or right angle bracket. 
 *			(see [7], [8] and [9])
 *			It is used as an escape character for all 
 *			other meta-characters, and itself. When used
 *			in a set ([4]), it is treated as an ordinary
 *			character.
 *
 *      [4]     [set]   matches one of the characters in the set.
 *                      If the first character in the set is "^",
 *                      it matches a character NOT in the set. A
 *                      shorthand S-E is used to specify a set of
 *                      characters S upto E, inclusive. The special
 *                      characters "]" and "-" have no special
 *                      meaning if they appear as the first chars
 *                      in the set.
 *                      examples:        match:
 *
 *                              [a-z]    any lowercase alpha
 *
 *                              [^]-]    any char except ] and -
 *
 *                              [^A-Z]   any char except uppercase
 *                                       alpha
 *
 *                              [a-zA-Z] any alpha
 *
 *      [5]     *       any regular expression form [1] to [4], followed by
 *                      closure char (*) matches zero or more matches of
 *                      that form.
 *
 *      [6]     +       same as [5], except it matches one or more.
 *
 *      [7]             a regular expression in the form [1] to [10], enclosed
 *                      as \(form\) matches what form matches. The enclosure
 *                      creates a set of tags, used for [8] and for
 *                      pattern substution. The tagged forms are numbered
 *			starting from 1.
 *
 *      [8]             a \ followed by a digit 1 to 9 matches whatever a
 *                      previously tagged regular expression ([7]) matched.
 *
 *	[9]	\<	a regular expression starting with a \< construct
 *		\>	and/or ending with a \> construct, restricts the
 *			pattern matching to the beginning of a word, and/or
 *			the end of a word. A word is defined to be a character
 *			string beginning and/or ending with the characters
 *			A-Z a-z 0-9 and _. It must also be preceded and/or
 *			followed by any character outside those mentioned.
 *
 *      [10]            a composite regular expression xy where x and y
 *                      are in the form [1] to [10] matches the longest
 *                      match of x followed by a match for y.
 *
 *      [11]	^	a regular expression starting with a ^ character
 *		$	and/or ending with a $ character, restricts the
 *                      pattern matching to the beginning of the line,
 *                      or the end of line. [anchors] Elsewhere in the
 *			pattern, ^ and $ are treated as ordinary characters.
 *
 *
 * Acknowledgements:
 *
 *	HCR's Hugh Redelmeier has been most helpful in various
 *	stages of development. He convinced me to include BOW
 *	and EOW constructs, originally invented by Rob Pike at
 *	the University of Toronto.
 *
 * References:
 *              Software tools			Kernighan & Plauger
 *              Software tools in Pascal        Kernighan & Plauger
 *              Grep [rsx-11 C dist]            David Conroy
 *		ed - text editor		Un*x Programmer's Manual
 *		Advanced editing on Un*x	B. W. Kernighan
 *		RegExp routines			Henry Spencer
 *
 * Notes:
 *
 *	This implementation uses a bit-set representation for character
 *	classes for speed and compactness. Each character is represented 
 *	by one bit in a 128-bit block. Thus, CCL or NCL always takes a 
 *	constant 16 bytes in the internal dfa, and s_re_exec does a single
 *	bit comparison to locate the character in the set.
 *
 * Examples:
 *
 *	pattern:	foo*.*
 *	compile:	CHR f CHR o CLO CHR o END CLO ANY END END
 *	matches:	fo foo fooo foobar fobar foxx ...
 *
 *	pattern:	fo[ob]a[rz]	
 *	compile:	CHR f CHR o CCL 2 o b CHR a CCL bitset END
 *	matches:	fobar fooar fobaz fooaz
 *
 *	pattern:	foo\\+
 *	compile:	CHR f CHR o CHR o CHR \ CLO CHR \ END END
 *	matches:	foo\ foo\\ foo\\\  ...
 *
 *	pattern:	\(foo\)[1-3]\1	(same as foo[1-3]foo)
 *	compile:	BOT 1 CHR f CHR o CHR o EOT 1 CCL bitset REF 1 END
 *	matches:	foo1foo foo2foo foo3foo
 *
 *	pattern:	\(fo.*\)-\1
 *	compile:	BOT 1 CHR f CHR o CLO ANY END EOT 1 CHR - REF 1 END
 *	matches:	foo-foo fo-fo fob-fob foobar-foobar ...
 * 
 */

#define MAXDFA  1024
#define MAXTAG  10

#define OKP     1
#define NOP     0

#define CHR     1
#define ANY     2
#define CCL     3
#define NCL     4
#define BOL     5
#define EOL     6
#define BOT     7
#define EOT     8
#define BOW	9
#define EOW	10
#define REF     11
#define CLO     12

#define END     0

/*
 * The following defines are not meant
 * to be changeable. They are for readibility
 * only.
 *
 */
#define MAXCHR	128
#define CHRBIT	8
#define BITBLK	MAXCHR/CHRBIT
#define BLKIND	0170
#define BITIND	07

#define ASCIIB	0177

typedef unsigned char CHAR;

static int  tagstk[MAXTAG];             /* subpat tag stack..*/
static CHAR dfa[MAXDFA];		/* automaton..       */
static int  sta = NOP;               	/* status of lastpat */

static CHAR bittab[BITBLK];		/* bit table for CCL */

static void
chset(c)
register CHAR c;
{
    bittab[((int) ((c)&BLKIND))>>3] |= 1<<((c)& (unsigned) BITIND);
}

#define badpat(x)	return(*dfa = END, x)
#define store(x)	*mp++ = x
 
char *     
s_re_comp(pat)
char *pat;
{
	register char *p;               /* pattern pointer   */
	register CHAR *mp=dfa;          /* dfa pointer       */
	register CHAR *lp;              /* saved pointer..   */
	register CHAR *sp=dfa;          /* another one..     */

	register int tagi = 0;          /* tag stack index   */
	register int tagc = 1;          /* actual tag count  */

	register int n;
	int c1, c2;
		
	if (!pat || !*pat) {
		if (sta)
			return(0);
		else
			badpat("No previous regular expression");
	}		
	sta = NOP;

	for (p = pat; *p; p++) {
		lp = mp;
		switch(*p) {

		case '.':               /* match any char..  */
			store(ANY);
			break;

		case '^':               /* match beginning.. */
			if (p == pat)
				store(BOL);
			else {
				store(CHR);
				store(*p);
			}
			break;

		case '$':               /* match endofline.. */
			if (!*(p+1))
				store(EOL);
			else {
				store(CHR);
				store(*p);
			}
			break;

		case '[':               /* match char class..*/

			if (*++p == '^') {
				store(NCL);
				p++;
			}
			else
				store(CCL);

			if (*p == '-')		/* real dash */
				chset(*p++);
			if (*p == ']')		/* real brac */
				chset(*p++);
			while (*p && *p != ']') {
				if (*p == '-' && *(p+1) && *(p+1) != ']') {
					p++;
					c1 = *(p-2) + 1;
					c2 = *p++;
					while (c1 <= c2)
						chset(c1++);
				}
#ifdef EXTEND
				else if (*p == '\\' && *(p+1)) {
					p++;
					chset(*p++);
				}
#endif
				else
					chset(*p++);
			}
			if (!*p)
				badpat("Missing ]");

			for (n = 0; n < BITBLK; bittab[n++] = (char) 0)
				store(bittab[n]);
	
			break;

		case '*':               /* match 0 or more.. */
		case '+':               /* match 1 or more.. */
			if (p == pat)
				badpat("Empty closure");
			lp = sp;                /* previous opcode */
			if (*lp == CLO)         /* equivalence..   */
				break;
			switch(*lp) {

			case BOL:
			case BOT:
			case EOT:
			case BOW:
			case EOW:
			case REF:
				badpat("Illegal closure");
			default:
				break;
			}

			if (*p == '+')
				for (sp = mp; lp < sp; lp++)
					store(*lp);

			store(END);
			store(END);
			sp = mp;
			while (--mp > lp)
				*mp = mp[-1];
			store(CLO);
			mp = sp;
			break;

		case '\\':              /* tags, backrefs .. */
			switch(*++p) {

			case '(':
				if (tagc < MAXTAG) {
					tagstk[++tagi] = tagc;
					store(BOT);
					store(tagc++);
				}
				else
					badpat("Too many \\(\\) pairs");
				break;
			case ')':
				if (*sp == BOT)
					badpat("Null pattern inside \\(\\)");
				if (tagi > 0) {
					store(EOT);
					store(tagstk[tagi--]);
				}
				else
					badpat("Unmatched \\)");
				break;
			case '<':
				store(BOW);
				break;
			case '>':
				if (*sp == BOW)
					badpat("Null pattern inside \\<\\>");
				store(EOW);
				break;
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9':
				n = *p-'0';
				if (tagi > 0 && tagstk[tagi] == n)
					badpat("Cyclical reference");
				if (tagc > n) {
					store(REF);
					store(n);
				}
				else
					badpat("Undetermined reference");
				break;
#ifdef EXTEND
			case 'b':
				store(CHR);
				store('\b');
				break;
			case 'n':
				store(CHR);
				store('\n');
				break;
			case 'f':
				store(CHR);
				store('\f');
				break;
			case 'r':
				store(CHR);
				store('\r');
				break;
			case 't':
				store(CHR);
				store('\t');
				break;
#endif
			default:
				store(CHR);
				store(*p);
			}
			break;

		default :               /* an ordinary char  */
			store(CHR);
			store(*p);
			break;
		}
		sp = lp;
	}
	if (tagi > 0)
		badpat("Unmatched \\(");
	store(END);
	sta = OKP;
	return(0);
}


static char *bol;
static char *bopat[MAXTAG];
static char *eopat[MAXTAG];
static char *pmatch();

/*
 * s_re_exec:
 * 	execute dfa to find a match.
 *
 *	special cases: (dfa[0])	
 *		BOL
 *			Match only once, starting from the
 *			beginning.
 *		CHR
 *			First locate the character without
 *			calling pmatch, and if found, call
 *			pmatch for the remaining string.
 *		END
 *			s_re_comp failed, poor luser did not
 *			check for it. Fail fast.
 *
 *	If a match is found, bopat[0] and eopat[0] are set
 *	to the beginning and the end of the matched fragment,
 *	respectively.
 *
 */

int
s_re_exec(lp)
register char *lp;
{
	register char c;
	register char *ep = 0;
	register CHAR *ap = dfa;

	bol = lp;

	bopat[0] = 0;
	bopat[1] = 0;
	bopat[2] = 0;
	bopat[3] = 0;
	bopat[4] = 0;
	bopat[5] = 0;
	bopat[6] = 0;
	bopat[7] = 0;
	bopat[8] = 0;
	bopat[9] = 0;

	switch(*ap) {

	case BOL:			/* anchored: match from BOL only */
		ep = pmatch(lp,ap);
		break;
	case CHR:			/* ordinary char: locate it fast */
		c = *(ap+1);
		while (*lp && *lp != c)
			lp++;
		if (!*lp)		/* if EOS, fail, else fall thru. */
			return(0);
	default:			/* regular matching all the way. */
		while (*lp) {
			if ((ep = pmatch(lp,ap)))
				break;
			lp++;
		}
		break;
	case END:			/* munged automaton. fail always */
		return(0);
	}
	if (!ep)
		return(0);

	bopat[0] = lp;
	eopat[0] = ep;
	return(1);
}

/* 
 * pmatch: 
 *	internal routine for the hard part
 *
 * 	This code is mostly snarfed from an early
 * 	grep written by David Conroy. The backref and
 * 	tag stuff, and various other mods are by oZ.
 *
 *	special cases: (dfa[n], dfa[n+1])
 *		CLO ANY
 *			We KNOW ".*" will match ANYTHING
 *			upto the end of line. Thus, go to
 *			the end of line straight, without
 *			calling pmatch recursively. As in
 *			the other closure cases, the remaining
 *			pattern must be matched by moving
 *			backwards on the string recursively,
 *			to find a match for xy (x is ".*" and 
 *			y is the remaining pattern) where
 *			the match satisfies the LONGEST match
 *			for x followed by a match for y.
 *		CLO CHR
 *			We can again scan the string forward
 *			for the single char without recursion, 
 *			and at the point of failure, we execute 
 *			the remaining dfa recursively, as
 *			described above.
 *
 *	At the end of a successful match, bopat[n] and eopat[n]
 *	are set to the beginning and end of subpatterns matched
 *	by tagged expressions (n = 1 to 9).	
 *
 */

extern void s_re_fail();

/*
 * character classification table for word boundary
 * operators BOW and EOW. the reason for not using 
 * ctype macros is that we can let the user add into 
 * our own table. see s_re_modw. This table is not in
 * the bitset form, since we may wish to extend it
 * in the future for other character classifications. 
 *
 *	TRUE for 0-9 A-Z a-z _
 */
static char chrtyp[MAXCHR] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 
	1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 
	0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
	1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
	1, 1, 1, 0, 0, 0, 0, 0
	};

#define inascii(x)	(0177&(x))
#define iswordc(x) 	chrtyp[inascii(x)]
#define isinset(x,y) 	((x)[((y)&BLKIND)>>3] & (1<<((y)&BITIND)))

/*
 * skip values for CLO XXX to skip past the closure
 *
 */

#define ANYSKIP	2 	/* CLO ANY END ...	   */
#define CHRSKIP	3	/* CLO CHR chr END ...	   */
#define CCLSKIP 18	/* CLO CCL 16bytes END ... */

static char *
pmatch(lp, ap)
register char *lp;
register CHAR *ap;
{
	register char *e;		/* extra pointer for CLO */
	register char *bp;		/* beginning of subpat.. */
	register char *ep;		/* ending of subpat..	 */
	register int op, c, n;
	char *are;			/* to save the line ptr. */

	while ((op = *ap++) != END)
		switch(op) {

		case CHR:
			if ((unsigned char) *lp++ != *ap++)
				return(0);
			break;
		case ANY:
			if (!*lp++)
				return(0);
			break;
		case CCL:
			c = *lp++;
			if (!isinset(ap,c))
				return(0);
			ap += BITBLK;
			break;
		case NCL:
			c = *lp++;
			if (isinset(ap,c))
				return(0);
			ap += BITBLK;
			break;
		case BOL:
			if (lp != bol)
				return(0);
			break;
		case EOL:
			if (*lp)
				return(0);
			break;
		case BOT:
			bopat[*ap++] = lp;
			break;
		case EOT:
			eopat[*ap++] = lp;
			break;
 		case BOW:
			if (!(lp!=bol && iswordc(lp[-1])) && iswordc(*lp))
				break;
			return(0);
		case EOW:
			if ((lp!=bol && iswordc(lp[-1])) && !iswordc(*lp))
				break;
			return(0);
		case REF:
			n = *ap++;
			bp = bopat[n];
			ep = eopat[n];
			while (bp < ep)
				if (*bp++ != *lp++)
					return(0);
			break;
		case CLO:
			are = lp;
			switch(*ap) {

			case ANY:
				while (*lp)
					lp++;
				n = ANYSKIP;
				break;
			case CHR:
				c = *(ap+1);
				while (*lp && c == *lp)
					lp++;
				n = CHRSKIP;
				break;
			case CCL:
			case NCL:
				while (*lp && (e = pmatch(lp, ap)))
					lp = e;
				n = CCLSKIP;
				break;
			default:
				s_re_fail("closure: bad dfa.", *ap);
				return(0);
			}

			ap += n;

			while (lp >= are) {
				if ((e = pmatch(lp, ap)))
					return(e);
				--lp;
			}
			return(0);
		default:
			s_re_fail("s_re_exec: bad dfa.", op);
			return(0);
		}
	return(lp);
}

/*
 * s_re_modw:
 *	add new characters into the word table to
 *	change the s_re_exec's understanding of what
 *	a word should look like. Note that we only
 *	accept additions into the word definition.
 *
 *	If the string parameter is 0 or null string,
 *	the table is reset back to the default, which
 *	contains A-Z a-z 0-9 _. [We use the compact
 *	bitset representation for the default table]
 *
 */

static unsigned char deftab[16] = {	
	0, 0, 0, 0, 0, 0, 0377, 003, 0376, 0377, 0377, 0207,  
	0376, 0377, 0377, 007 
}; 

void
s_re_modw(s)
register char *s;
{
	register int i;

	if (!s || !*s) {
		for (i = 0; i < MAXCHR; i++)
			if (!isinset(deftab,i))
				iswordc(i) = 0;
	}
	else
		while(*s)
			iswordc(*s++) = 1;
}

/*
 * s_re_subs:
 *	substitute the matched portions of the src in
 *	dst.
 *
 *	&	substitute the entire matched pattern.
 *
 *	\digit	substitute a subpattern, with the given
 *		tag number. Tags are numbered from 1 to
 *		9. If the particular tagged subpattern
 *		does not exist, null is substituted.
 *
 */
int
s_re_subs(src, dst)
register char *src;
register char *dst;
{
	register char c;
	register int  pin;
	register char *bp;
	register char *ep;

	if (!*src || !bopat[0])
		return(0);

	while ((c = *src++)) {
		switch(c) {

		case '&':
			pin = 0;
			break;

		case '\\':
			c = *src++;
			if (c >= '0' && c <= '9') {
				pin = c - '0';
				break;
			}
			
		default:
			*dst++ = c;
			continue;
		}

		if ((bp = bopat[pin]) && (ep = eopat[pin])) {
			while (*bp && bp < ep)
				*dst++ = *bp++;
			if (bp < ep)
				return(0);
		}
	}
	*dst = (char) 0;
	return(1);
}
			
#ifdef DEBUG
/*
 * symbolic - produce a symbolic dump of the
 *            dfa
 */
symbolic(s) 
char *s;
{
	printf("pattern: %s\n", s);
	printf("dfacode:\n");
	dfadump(dfa);
}

static	
dfadump(ap)
CHAR *ap;
{
	register int n;

	while (*ap != END)
		switch(*ap++) {
		case CLO:
			printf("CLOSURE");
			dfadump(ap);
			switch(*ap) {
			case CHR:
				n = CHRSKIP;
				break;
			case ANY:
				n = ANYSKIP;
				break;
			case CCL:
			case NCL:
				n = CCLSKIP;
				break;
			}
			ap += n;
			break;
		case CHR:
			printf("\tCHR %c\n",*ap++);
			break;
		case ANY:
			printf("\tANY .\n");
			break;
		case BOL:
			printf("\tBOL -\n");
			break;
		case EOL:
			printf("\tEOL -\n");
			break;
		case BOT:
			printf("BOT: %d\n",*ap++);
			break;
		case EOT:
			printf("EOT: %d\n",*ap++);
			break;
		case BOW:
			printf("BOW\n");
			break;
		case EOW:
			printf("EOW\n");
			break;
		case REF:
			printf("REF: %d\n",*ap++);
			break;
		case CCL:
			printf("\tCCL [");
			for (n = 0; n < MAXCHR; n++)
				if (isinset(ap,(CHAR)n))
					printf("%c",n);
			printf("]\n");
			ap += BITBLK;
			break;
		case NCL:
			printf("\tNCL [");
			for (n = 0; n < MAXCHR; n++)
				if (isinset(ap,(CHAR)n))
					printf("%c",n);
			printf("]\n");
			ap += BITBLK;
			break;
		default:
			printf("bad dfa. opcode %o\n", ap[-1]);
			exit(1);
			break;
		}
}
#endif