xref: /netbsd-src/lib/libc/stdio/vfscanf.c (revision a536ee5124e62c9a0051a252f7833dc8f50f44c9)
1 /*	$NetBSD: vfscanf.c,v 1.43 2012/03/15 18:22:30 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)vfscanf.c	8.1 (Berkeley) 6/4/93";
39 __FBSDID("$FreeBSD: src/lib/libc/stdio/vfscanf.c,v 1.41 2007/01/09 00:28:07 imp Exp $");
40 #else
41 __RCSID("$NetBSD: vfscanf.c,v 1.43 2012/03/15 18:22:30 christos Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include "namespace.h"
46 #include <assert.h>
47 #include <ctype.h>
48 #include <inttypes.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <stddef.h>
52 #include <stdarg.h>
53 #include <string.h>
54 #include <wchar.h>
55 #include <wctype.h>
56 
57 #include "reentrant.h"
58 #include "local.h"
59 
60 #ifndef NO_FLOATING_POINT
61 #include <locale.h>
62 #endif
63 
64 /*
65  * Provide an external name for vfscanf.  Note, we don't use the normal
66  * namespace.h method; stdio routines explicitly use the internal name
67  * __svfscanf.
68  */
69 #ifdef __weak_alias
70 __weak_alias(vfscanf,__svfscanf)
71 #endif
72 
73 #define	BUF		513	/* Maximum length of numeric string. */
74 
75 /*
76  * Flags used during conversion.
77  */
78 #define	LONG		0x0001	/* l: long or double */
79 #define	LONGDBL		0x0002	/* L: long double */
80 #define	SHORT		0x0004	/* h: short */
81 #define	SUPPRESS	0x0008	/* *: suppress assignment */
82 #define	POINTER		0x0010	/* p: void * (as hex) */
83 #define	NOSKIP		0x0020	/* [ or c: do not skip blanks */
84 #define	LONGLONG	0x0400	/* ll: long long (+ deprecated q: quad) */
85 #define	INTMAXT		0x0800	/* j: intmax_t */
86 #define	PTRDIFFT	0x1000	/* t: ptrdiff_t */
87 #define	SIZET		0x2000	/* z: size_t */
88 #define	SHORTSHORT	0x4000	/* hh: char */
89 #define	UNSIGNED	0x8000	/* %[oupxX] conversions */
90 
91 /*
92  * The following are used in integral conversions only:
93  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS
94  */
95 #define	SIGNOK		0x00040	/* +/- is (still) legal */
96 #define	NDIGITS		0x00080	/* no digits detected */
97 #define	PFXOK		0x00100	/* 0x prefix is (still) legal */
98 #define	NZDIGITS	0x00200	/* no zero digits detected */
99 #define	HAVESIGN	0x10000	/* sign detected */
100 
101 /*
102  * Conversion types.
103  */
104 #define	CT_CHAR		0	/* %c conversion */
105 #define	CT_CCL		1	/* %[...] conversion */
106 #define	CT_STRING	2	/* %s conversion */
107 #define	CT_INT		3	/* %[dioupxX] conversion */
108 #define	CT_FLOAT	4	/* %[efgEFG] conversion */
109 
110 static const u_char *__sccl(char *, const u_char *);
111 #ifndef NO_FLOATING_POINT
112 static size_t parsefloat(FILE *, char *, char *);
113 #endif
114 
115 int __scanfdebug = 0;
116 
117 #define __collate_load_error /*CONSTCOND*/0
118 static int
119 __collate_range_cmp(int c1, int c2)
120 {
121 	static char s1[2], s2[2];
122 
123 	s1[0] = c1;
124 	s2[0] = c2;
125 	return strcoll(s1, s2);
126 }
127 
128 
129 /*
130  * __svfscanf - MT-safe version
131  */
132 int
133 __svfscanf(FILE *fp, char const *fmt0, va_list ap)
134 {
135 	int ret;
136 
137 	FLOCKFILE(fp);
138 	ret = __svfscanf_unlocked(fp, fmt0, ap);
139 	FUNLOCKFILE(fp);
140 	return ret;
141 }
142 
143 #define SCANF_SKIP_SPACE() \
144 do { \
145 	while ((fp->_r > 0 || __srefill(fp) == 0) && isspace(*fp->_p)) \
146 		nread++, fp->_r--, fp->_p++; \
147 } while (/*CONSTCOND*/ 0)
148 
149 /*
150  * __svfscanf_unlocked - non-MT-safe version of __svfscanf
151  */
152 int
153 __svfscanf_unlocked(FILE *fp, const char *fmt0, va_list ap)
154 {
155 	const u_char *fmt = (const u_char *)fmt0;
156 	int c;			/* character from format, or conversion */
157 	size_t width;		/* field width, or 0 */
158 	char *p;		/* points into all kinds of strings */
159 	size_t n;		/* handy size_t */
160 	int flags;		/* flags as defined above */
161 	char *p0;		/* saves original value of p when necessary */
162 	int nassigned;		/* number of fields assigned */
163 	int nconversions;	/* number of conversions */
164 	size_t nread;		/* number of characters consumed from fp */
165 	int base;		/* base argument to conversion function */
166 	char ccltab[256];	/* character class table for %[...] */
167 	char buf[BUF];		/* buffer for numeric and mb conversions */
168 	wchar_t *wcp;		/* handy wide-character pointer */
169 	size_t nconv;		/* length of multibyte sequence converted */
170 	static const mbstate_t initial;
171 	mbstate_t mbs;
172 
173 	/* `basefix' is used to avoid `if' tests in the integer scanner */
174 	static const short basefix[17] =
175 		{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
176 
177 	_DIAGASSERT(fp != NULL);
178 	_DIAGASSERT(fmt0 != NULL);
179 
180 	_SET_ORIENTATION(fp, -1);
181 
182 	nassigned = 0;
183 	nconversions = 0;
184 	nread = 0;
185 	base = 0;
186 	for (;;) {
187 		c = (unsigned char)*fmt++;
188 		if (c == 0)
189 			return nassigned;
190 		if (isspace(c)) {
191 			while ((fp->_r > 0 || __srefill(fp) == 0) &&
192 			    isspace(*fp->_p))
193 				nread++, fp->_r--, fp->_p++;
194 			continue;
195 		}
196 		if (c != '%')
197 			goto literal;
198 		width = 0;
199 		flags = 0;
200 		/*
201 		 * switch on the format.  continue if done;
202 		 * break once format type is derived.
203 		 */
204 again:		c = *fmt++;
205 		switch (c) {
206 		case '%':
207 			SCANF_SKIP_SPACE();
208 literal:
209 			if (fp->_r <= 0 && __srefill(fp))
210 				goto input_failure;
211 			if (*fp->_p != c)
212 				goto match_failure;
213 			fp->_r--, fp->_p++;
214 			nread++;
215 			continue;
216 
217 		case '*':
218 			flags |= SUPPRESS;
219 			goto again;
220 		case 'j':
221 			flags |= INTMAXT;
222 			goto again;
223 		case 'l':
224 			if (flags & LONG) {
225 				flags &= ~LONG;
226 				flags |= LONGLONG;
227 			} else
228 				flags |= LONG;
229 			goto again;
230 		case 'q':
231 			flags |= LONGLONG;	/* not quite */
232 			goto again;
233 		case 't':
234 			flags |= PTRDIFFT;
235 			goto again;
236 		case 'z':
237 			flags |= SIZET;
238 			goto again;
239 		case 'L':
240 			flags |= LONGDBL;
241 			goto again;
242 		case 'h':
243 			if (flags & SHORT) {
244 				flags &= ~SHORT;
245 				flags |= SHORTSHORT;
246 			} else
247 				flags |= SHORT;
248 			goto again;
249 
250 		case '0': case '1': case '2': case '3': case '4':
251 		case '5': case '6': case '7': case '8': case '9':
252 			width = width * 10 + c - '0';
253 			goto again;
254 
255 		/*
256 		 * Conversions.
257 		 */
258 		case 'd':
259 			c = CT_INT;
260 			base = 10;
261 			break;
262 
263 		case 'i':
264 			c = CT_INT;
265 			base = 0;
266 			break;
267 
268 		case 'o':
269 			c = CT_INT;
270 			flags |= UNSIGNED;
271 			base = 8;
272 			break;
273 
274 		case 'u':
275 			c = CT_INT;
276 			flags |= UNSIGNED;
277 			base = 10;
278 			break;
279 
280 		case 'X':
281 		case 'x':
282 			flags |= PFXOK;	/* enable 0x prefixing */
283 			c = CT_INT;
284 			flags |= UNSIGNED;
285 			base = 16;
286 			break;
287 
288 #ifndef NO_FLOATING_POINT
289 		case 'A': case 'E': case 'F': case 'G':
290 		case 'a': case 'e': case 'f': case 'g':
291 			c = CT_FLOAT;
292 			break;
293 #endif
294 
295 		case 'S':
296 			flags |= LONG;
297 			/* FALLTHROUGH */
298 		case 's':
299 			c = CT_STRING;
300 			break;
301 
302 		case '[':
303 			fmt = __sccl(ccltab, fmt);
304 			flags |= NOSKIP;
305 			c = CT_CCL;
306 			break;
307 
308 		case 'C':
309 			flags |= LONG;
310 			/* FALLTHROUGH */
311 		case 'c':
312 			flags |= NOSKIP;
313 			c = CT_CHAR;
314 			break;
315 
316 		case 'p':	/* pointer format is like hex */
317 			flags |= POINTER | PFXOK;
318 			c = CT_INT;		/* assumes sizeof(uintmax_t) */
319 			flags |= UNSIGNED;	/*      >= sizeof(uintptr_t) */
320 			base = 16;
321 			break;
322 
323 		case 'n':
324 			nconversions++;
325 			if (flags & SUPPRESS)	/* ??? */
326 				continue;
327 			if (flags & SHORTSHORT)
328 				*va_arg(ap, char *) = (char)nread;
329 			else if (flags & SHORT)
330 				*va_arg(ap, short *) = (short)nread;
331 			else if (flags & LONG)
332 				*va_arg(ap, long *) = nread;
333 			else if (flags & LONGLONG)
334 				*va_arg(ap, long long *) = nread;
335 			else if (flags & INTMAXT)
336 				*va_arg(ap, intmax_t *) = nread;
337 			else if (flags & SIZET)
338 				*va_arg(ap, size_t *) = nread;
339 			else if (flags & PTRDIFFT)
340 				*va_arg(ap, ptrdiff_t *) = nread;
341 			else
342 				*va_arg(ap, int *) = (int)nread;
343 			continue;
344 
345 		default:
346 			goto match_failure;
347 
348 		/*
349 		 * Disgusting backwards compatibility hack.	XXX
350 		 */
351 		case '\0':	/* compat */
352 			return EOF;
353 		}
354 
355 		/*
356 		 * We have a conversion that requires input.
357 		 */
358 		if (fp->_r <= 0 && __srefill(fp))
359 			goto input_failure;
360 
361 		/*
362 		 * Consume leading white space, except for formats
363 		 * that suppress this.
364 		 */
365 		if ((flags & NOSKIP) == 0) {
366 			while (isspace(*fp->_p)) {
367 				nread++;
368 				if (--fp->_r > 0)
369 					fp->_p++;
370 				else if (__srefill(fp))
371 					goto input_failure;
372 			}
373 			/*
374 			 * Note that there is at least one character in
375 			 * the buffer, so conversions that do not set NOSKIP
376 			 * ca no longer result in an input failure.
377 			 */
378 		}
379 
380 		/*
381 		 * Do the conversion.
382 		 */
383 		switch (c) {
384 
385 		case CT_CHAR:
386 			/* scan arbitrary characters (sets NOSKIP) */
387 			if (width == 0)
388 				width = 1;
389 			if (flags & LONG) {
390 				if ((flags & SUPPRESS) == 0)
391 					wcp = va_arg(ap, wchar_t *);
392 				else
393 					wcp = NULL;
394 				n = 0;
395 				while (width != 0) {
396 					if (n == MB_CUR_MAX) {
397 						fp->_flags |= __SERR;
398 						goto input_failure;
399 					}
400 					buf[n++] = *fp->_p;
401 					fp->_p++;
402 					fp->_r--;
403 					mbs = initial;
404 					nconv = mbrtowc(wcp, buf, n, &mbs);
405 					if (nconv == (size_t)-1) {
406 						fp->_flags |= __SERR;
407 						goto input_failure;
408 					}
409 					if (nconv == 0 && !(flags & SUPPRESS))
410 						*wcp = L'\0';
411 					if (nconv != (size_t)-2) {
412 						nread += n;
413 						width--;
414 						if (!(flags & SUPPRESS))
415 							wcp++;
416 						n = 0;
417 					}
418 					if (fp->_r <= 0 && __srefill(fp)) {
419 						if (n != 0) {
420 							fp->_flags |= __SERR;
421 							goto input_failure;
422 						}
423 						break;
424 					}
425 				}
426 				if (!(flags & SUPPRESS))
427 					nassigned++;
428 			} else if (flags & SUPPRESS) {
429 				size_t sum = 0;
430 				for (;;) {
431 					if ((n = fp->_r) < width) {
432 						sum += n;
433 						width -= n;
434 						fp->_p += n;
435 						if (__srefill(fp)) {
436 							if (sum == 0)
437 							    goto input_failure;
438 							break;
439 						}
440 					} else {
441 						sum += width;
442 						_DIAGASSERT(__type_fit(int,
443 						    fp->_r - width));
444 						fp->_r -= (int)width;
445 						fp->_p += width;
446 						break;
447 					}
448 				}
449 				nread += sum;
450 			} else {
451 				size_t r = fread(va_arg(ap, char *), 1,
452 				    width, fp);
453 
454 				if (r == 0)
455 					goto input_failure;
456 				nread += r;
457 				nassigned++;
458 			}
459 			nconversions++;
460 			break;
461 
462 		case CT_CCL:
463 			/* scan a (nonempty) character class (sets NOSKIP) */
464 			if (width == 0)
465 				width = (size_t)~0;	/* `infinity' */
466 			/* take only those things in the class */
467 			if (flags & LONG) {
468 				wchar_t twc;
469 				int nchars;
470 
471 				if ((flags & SUPPRESS) == 0)
472 					wcp = va_arg(ap, wchar_t *);
473 				else
474 					wcp = &twc;
475 				n = 0;
476 				nchars = 0;
477 				while (width != 0) {
478 					if (n == MB_CUR_MAX) {
479 						fp->_flags |= __SERR;
480 						goto input_failure;
481 					}
482 					buf[n++] = *fp->_p;
483 					fp->_p++;
484 					fp->_r--;
485 					mbs = initial;
486 					nconv = mbrtowc(wcp, buf, n, &mbs);
487 					if (nconv == (size_t)-1) {
488 						fp->_flags |= __SERR;
489 						goto input_failure;
490 					}
491 					if (nconv == 0)
492 						*wcp = L'\0';
493 					if (nconv != (size_t)-2) {
494 						if (wctob(*wcp) != EOF &&
495 						    !ccltab[wctob(*wcp)]) {
496 							while (n != 0) {
497 								n--;
498 								(void)ungetc(buf[n],
499 								    fp);
500 							}
501 							break;
502 						}
503 						nread += n;
504 						width--;
505 						if (!(flags & SUPPRESS))
506 							wcp++;
507 						nchars++;
508 						n = 0;
509 					}
510 					if (fp->_r <= 0 && __srefill(fp)) {
511 						if (n != 0) {
512 							fp->_flags |= __SERR;
513 							goto input_failure;
514 						}
515 						break;
516 					}
517 				}
518 				if (n != 0) {
519 					fp->_flags |= __SERR;
520 					goto input_failure;
521 				}
522 				n = nchars;
523 				if (n == 0)
524 					goto match_failure;
525 				if (!(flags & SUPPRESS)) {
526 					*wcp = L'\0';
527 					nassigned++;
528 				}
529 			} else if (flags & SUPPRESS) {
530 				n = 0;
531 				while (ccltab[*fp->_p]) {
532 					n++, fp->_r--, fp->_p++;
533 					if (--width == 0)
534 						break;
535 					if (fp->_r <= 0 && __srefill(fp)) {
536 						if (n == 0)
537 							goto input_failure;
538 						break;
539 					}
540 				}
541 				if (n == 0)
542 					goto match_failure;
543 			} else {
544 				p0 = p = va_arg(ap, char *);
545 				while (ccltab[*fp->_p]) {
546 					fp->_r--;
547 					*p++ = *fp->_p++;
548 					if (--width == 0)
549 						break;
550 					if (fp->_r <= 0 && __srefill(fp)) {
551 						if (p == p0)
552 							goto input_failure;
553 						break;
554 					}
555 				}
556 				n = p - p0;
557 				if (n == 0)
558 					goto match_failure;
559 				*p = 0;
560 				nassigned++;
561 			}
562 			nread += n;
563 			nconversions++;
564 			break;
565 
566 		case CT_STRING:
567 			/* like CCL, but zero-length string OK, & no NOSKIP */
568 			if (width == 0)
569 				width = (size_t)~0;
570 			if (flags & LONG) {
571 				wchar_t twc;
572 
573 				if ((flags & SUPPRESS) == 0)
574 					wcp = va_arg(ap, wchar_t *);
575 				else
576 					wcp = &twc;
577 				n = 0;
578 				while (!isspace(*fp->_p) && width != 0) {
579 					if (n == MB_CUR_MAX) {
580 						fp->_flags |= __SERR;
581 						goto input_failure;
582 					}
583 					buf[n++] = *fp->_p;
584 					fp->_p++;
585 					fp->_r--;
586 					mbs = initial;
587 					nconv = mbrtowc(wcp, buf, n, &mbs);
588 					if (nconv == (size_t)-1) {
589 						fp->_flags |= __SERR;
590 						goto input_failure;
591 					}
592 					if (nconv == 0)
593 						*wcp = L'\0';
594 					if (nconv != (size_t)-2) {
595 						if (iswspace(*wcp)) {
596 							while (n != 0) {
597 								n--;
598 								(void)ungetc(buf[n],
599 								    fp);
600 							}
601 							break;
602 						}
603 						nread += n;
604 						width--;
605 						if (!(flags & SUPPRESS))
606 							wcp++;
607 						n = 0;
608 					}
609 					if (fp->_r <= 0 && __srefill(fp)) {
610 						if (n != 0) {
611 							fp->_flags |= __SERR;
612 							goto input_failure;
613 						}
614 						break;
615 					}
616 				}
617 				if (!(flags & SUPPRESS)) {
618 					*wcp = L'\0';
619 					nassigned++;
620 				}
621 			} else if (flags & SUPPRESS) {
622 				n = 0;
623 				while (!isspace(*fp->_p)) {
624 					n++, fp->_r--, fp->_p++;
625 					if (--width == 0)
626 						break;
627 					if (fp->_r <= 0 && __srefill(fp))
628 						break;
629 				}
630 				nread += n;
631 			} else {
632 				p0 = p = va_arg(ap, char *);
633 				while (!isspace(*fp->_p)) {
634 					fp->_r--;
635 					*p++ = *fp->_p++;
636 					if (--width == 0)
637 						break;
638 					if (fp->_r <= 0 && __srefill(fp))
639 						break;
640 				}
641 				*p = 0;
642 				nread += p - p0;
643 				nassigned++;
644 			}
645 			nconversions++;
646 			continue;
647 
648 		case CT_INT:
649 			/* scan an integer as if by the conversion function */
650 #ifdef hardway
651 			if (width == 0 || width > sizeof(buf) - 1)
652 				width = sizeof(buf) - 1;
653 #else
654 			/* size_t is unsigned, hence this optimisation */
655 			if (--width > sizeof(buf) - 2)
656 				width = sizeof(buf) - 2;
657 			width++;
658 #endif
659 			flags |= SIGNOK | NDIGITS | NZDIGITS;
660 			for (p = buf; width; width--) {
661 				c = *fp->_p;
662 				/*
663 				 * Switch on the character; `goto ok'
664 				 * if we accept it as a part of number.
665 				 */
666 				switch (c) {
667 
668 				/*
669 				 * The digit 0 is always legal, but is
670 				 * special.  For %i conversions, if no
671 				 * digits (zero or nonzero) have been
672 				 * scanned (only signs), we will have
673 				 * base==0.  In that case, we should set
674 				 * it to 8 and enable 0x prefixing.
675 				 * Also, if we have not scanned zero digits
676 				 * before this, do not turn off prefixing
677 				 * (someone else will turn it off if we
678 				 * have scanned any nonzero digits).
679 				 */
680 				case '0':
681 					if (base == 0) {
682 						base = 8;
683 						flags |= PFXOK;
684 					}
685 					if (flags & NZDIGITS)
686 					    flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
687 					else
688 					    flags &= ~(SIGNOK|PFXOK|NDIGITS);
689 					goto ok;
690 
691 				/* 1 through 7 always legal */
692 				case '1': case '2': case '3':
693 				case '4': case '5': case '6': case '7':
694 					base = basefix[base];
695 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
696 					goto ok;
697 
698 				/* digits 8 and 9 ok iff decimal or hex */
699 				case '8': case '9':
700 					base = basefix[base];
701 					if (base <= 8)
702 						break;	/* not legal here */
703 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
704 					goto ok;
705 
706 				/* letters ok iff hex */
707 				case 'A': case 'B': case 'C':
708 				case 'D': case 'E': case 'F':
709 				case 'a': case 'b': case 'c':
710 				case 'd': case 'e': case 'f':
711 					/* no need to fix base here */
712 					if (base <= 10)
713 						break;	/* not legal here */
714 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
715 					goto ok;
716 
717 				/* sign ok only as first character */
718 				case '+': case '-':
719 					if (flags & SIGNOK) {
720 						flags &= ~SIGNOK;
721 						flags |= HAVESIGN;
722 						goto ok;
723 					}
724 					break;
725 
726 				/*
727 				 * x ok iff flag still set & 2nd char (or
728 				 * 3rd char if we have a sign).
729 				 */
730 				case 'x': case 'X':
731 					if (flags & PFXOK && p ==
732 					    buf + 1 + !!(flags & HAVESIGN)) {
733 						base = 16;	/* if %i */
734 						flags &= ~PFXOK;
735 						goto ok;
736 					}
737 					break;
738 				}
739 
740 				/*
741 				 * If we got here, c is not a legal character
742 				 * for a number.  Stop accumulating digits.
743 				 */
744 				break;
745 		ok:
746 				/*
747 				 * c is legal: store it and look at the next.
748 				 */
749 				*p++ = c;
750 				if (--fp->_r > 0)
751 					fp->_p++;
752 				else if (__srefill(fp))
753 					break;		/* EOF */
754 			}
755 			/*
756 			 * If we had only a sign, it is no good; push
757 			 * back the sign.  If the number ends in `x',
758 			 * it was [sign] '0' 'x', so push back the x
759 			 * and treat it as [sign] '0'.
760 			 */
761 			if (flags & NDIGITS) {
762 				if (p > buf)
763 					(void)ungetc(*(u_char *)--p, fp);
764 				goto match_failure;
765 			}
766 			c = ((u_char *)p)[-1];
767 			if (c == 'x' || c == 'X') {
768 				--p;
769 				(void)ungetc(c, fp);
770 			}
771 			if ((flags & SUPPRESS) == 0) {
772 				uintmax_t res;
773 
774 				*p = 0;
775 				if ((flags & UNSIGNED) == 0)
776 				    res = strtoimax(buf, (char **)NULL, base);
777 				else
778 				    res = strtoumax(buf, (char **)NULL, base);
779 				if (flags & POINTER)
780 					*va_arg(ap, void **) =
781 							(void *)(uintptr_t)res;
782 				else if (flags & SHORTSHORT)
783 					*va_arg(ap, char *) = (char)res;
784 				else if (flags & SHORT)
785 					*va_arg(ap, short *) = (short)res;
786 				else if (flags & LONG)
787 					*va_arg(ap, long *) = (long)res;
788 				else if (flags & LONGLONG)
789 					*va_arg(ap, long long *) = res;
790 				else if (flags & INTMAXT)
791 					*va_arg(ap, intmax_t *) = res;
792 				else if (flags & PTRDIFFT)
793 					*va_arg(ap, ptrdiff_t *) =
794 					    (ptrdiff_t)res;
795 				else if (flags & SIZET)
796 					*va_arg(ap, size_t *) = (size_t)res;
797 				else
798 					*va_arg(ap, int *) = (int)res;
799 				nassigned++;
800 			}
801 			nread += p - buf;
802 			nconversions++;
803 			break;
804 
805 #ifndef NO_FLOATING_POINT
806 		case CT_FLOAT:
807 			/* scan a floating point number as if by strtod */
808 			if (width == 0 || width > sizeof(buf) - 1)
809 				width = sizeof(buf) - 1;
810 			if ((width = parsefloat(fp, buf, buf + width)) == 0)
811 				goto match_failure;
812 			if ((flags & SUPPRESS) == 0) {
813 				if (flags & LONGDBL) {
814 					long double res = strtold(buf, &p);
815 					*va_arg(ap, long double *) = res;
816 				} else if (flags & LONG) {
817 					double res = strtod(buf, &p);
818 					*va_arg(ap, double *) = res;
819 				} else {
820 					float res = strtof(buf, &p);
821 					*va_arg(ap, float *) = res;
822 				}
823 				if (__scanfdebug && (size_t)(p - buf) != width)
824 					abort();
825 				nassigned++;
826 			}
827 			nread += width;
828 			nconversions++;
829 			break;
830 #endif /* !NO_FLOATING_POINT */
831 		}
832 	}
833 input_failure:
834 	return nconversions != 0 ? nassigned : EOF;
835 match_failure:
836 	return nassigned;
837 }
838 
839 /*
840  * Fill in the given table from the scanset at the given format
841  * (just after `[').  Return a pointer to the character past the
842  * closing `]'.  The table has a 1 wherever characters should be
843  * considered part of the scanset.
844  */
845 static const u_char *
846 __sccl(char *tab, const u_char *fmt)
847 {
848 	int c, n, v, i;
849 
850 	_DIAGASSERT(tab != NULL);
851 	_DIAGASSERT(fmt != NULL);
852 	/* first `clear' the whole table */
853 	c = *fmt++;		/* first char hat => negated scanset */
854 	if (c == '^') {
855 		v = 1;		/* default => accept */
856 		c = *fmt++;	/* get new first char */
857 	} else
858 		v = 0;		/* default => reject */
859 
860 	/* XXX: Will not work if sizeof(tab*) > sizeof(char) */
861 	(void)memset(tab, v, 256);
862 
863 	if (c == 0)
864 		return fmt - 1;/* format ended before closing ] */
865 
866 	/*
867 	 * Now set the entries corresponding to the actual scanset
868 	 * to the opposite of the above.
869 	 *
870 	 * The first character may be ']' (or '-') without being special;
871 	 * the last character may be '-'.
872 	 */
873 	v = 1 - v;
874 	for (;;) {
875 		tab[c] = v;		/* take character c */
876 doswitch:
877 		n = *fmt++;		/* and examine the next */
878 		switch (n) {
879 
880 		case 0:			/* format ended too soon */
881 			return fmt - 1;
882 
883 		case '-':
884 			/*
885 			 * A scanset of the form
886 			 *	[01+-]
887 			 * is defined as `the digit 0, the digit 1,
888 			 * the character +, the character -', but
889 			 * the effect of a scanset such as
890 			 *	[a-zA-Z0-9]
891 			 * is implementation defined.  The V7 Unix
892 			 * scanf treats `a-z' as `the letters a through
893 			 * z', but treats `a-a' as `the letter a, the
894 			 * character -, and the letter a'.
895 			 *
896 			 * For compatibility, the `-' is not considerd
897 			 * to define a range if the character following
898 			 * it is either a close bracket (required by ANSI)
899 			 * or is not numerically greater than the character
900 			 * we just stored in the table (c).
901 			 */
902 			n = *fmt;
903 			if (n == ']' || (__collate_load_error ? n < c :
904 			    __collate_range_cmp(n, c) < 0)) {
905 				c = '-';
906 				break;	/* resume the for(;;) */
907 			}
908 			fmt++;
909 			/* fill in the range */
910 			if (__collate_load_error) {
911 				do
912 					tab[++c] = v;
913 				while (c < n);
914 			} else {
915 				for (i = 0; i < 256; i ++)
916 					if (__collate_range_cmp(c, i) < 0 &&
917 					    __collate_range_cmp(i, n) <= 0)
918 						tab[i] = v;
919 			}
920 #if 1	/* XXX another disgusting compatibility hack */
921 			c = n;
922 			/*
923 			 * Alas, the V7 Unix scanf also treats formats
924 			 * such as [a-c-e] as `the letters a through e'.
925 			 * This too is permitted by the standard....
926 			 */
927 			goto doswitch;
928 #else
929 			c = *fmt++;
930 			if (c == 0)
931 				return fmt - 1;
932 			if (c == ']')
933 				return fmt;
934 #endif
935 
936 		case ']':		/* end of scanset */
937 			return fmt;
938 
939 		default:		/* just another character */
940 			c = n;
941 			break;
942 		}
943 	}
944 	/* NOTREACHED */
945 }
946 
947 #ifndef NO_FLOATING_POINT
948 static size_t
949 parsefloat(FILE *fp, char *buf, char *end)
950 {
951 	char *commit, *p;
952 	int infnanpos = 0;
953 	enum {
954 		S_START, S_GOTSIGN, S_INF, S_NAN, S_MAYBEHEX,
955 		S_DIGITS, S_FRAC, S_EXP, S_EXPDIGITS
956 	} state = S_START;
957 	unsigned char c;
958 	char decpt = *localeconv()->decimal_point;
959 	_Bool gotmantdig = 0, ishex = 0;
960 
961 	/*
962 	 * We set commit = p whenever the string we have read so far
963 	 * constitutes a valid representation of a floating point
964 	 * number by itself.  At some point, the parse will complete
965 	 * or fail, and we will ungetc() back to the last commit point.
966 	 * To ensure that the file offset gets updated properly, it is
967 	 * always necessary to read at least one character that doesn't
968 	 * match; thus, we can't short-circuit "infinity" or "nan(...)".
969 	 */
970 	commit = buf - 1;
971 	for (p = buf; p < end; ) {
972 		c = *fp->_p;
973 reswitch:
974 		switch (state) {
975 		case S_START:
976 			state = S_GOTSIGN;
977 			if (c == '-' || c == '+')
978 				break;
979 			else
980 				goto reswitch;
981 		case S_GOTSIGN:
982 			switch (c) {
983 			case '0':
984 				state = S_MAYBEHEX;
985 				commit = p;
986 				break;
987 			case 'I':
988 			case 'i':
989 				state = S_INF;
990 				break;
991 			case 'N':
992 			case 'n':
993 				state = S_NAN;
994 				break;
995 			default:
996 				state = S_DIGITS;
997 				goto reswitch;
998 			}
999 			break;
1000 		case S_INF:
1001 			if (infnanpos > 6 ||
1002 			    (c != "nfinity"[infnanpos] &&
1003 			     c != "NFINITY"[infnanpos]))
1004 				goto parsedone;
1005 			if (infnanpos == 1 || infnanpos == 6)
1006 				commit = p;	/* inf or infinity */
1007 			infnanpos++;
1008 			break;
1009 		case S_NAN:
1010 			switch (infnanpos) {
1011 			case -1:	/* XXX kludge to deal with nan(...) */
1012 				goto parsedone;
1013 			case 0:
1014 				if (c != 'A' && c != 'a')
1015 					goto parsedone;
1016 				break;
1017 			case 1:
1018 				if (c != 'N' && c != 'n')
1019 					goto parsedone;
1020 				else
1021 					commit = p;
1022 				break;
1023 			case 2:
1024 				if (c != '(')
1025 					goto parsedone;
1026 				break;
1027 			default:
1028 				if (c == ')') {
1029 					commit = p;
1030 					infnanpos = -2;
1031 				} else if (!isalnum(c) && c != '_')
1032 					goto parsedone;
1033 				break;
1034 			}
1035 			infnanpos++;
1036 			break;
1037 		case S_MAYBEHEX:
1038 			state = S_DIGITS;
1039 			if (c == 'X' || c == 'x') {
1040 				ishex = 1;
1041 				break;
1042 			} else {	/* we saw a '0', but no 'x' */
1043 				gotmantdig = 1;
1044 				goto reswitch;
1045 			}
1046 		case S_DIGITS:
1047 			if ((ishex && isxdigit(c)) || isdigit(c))
1048 				gotmantdig = 1;
1049 			else {
1050 				state = S_FRAC;
1051 				if (c != decpt)
1052 					goto reswitch;
1053 			}
1054 			if (gotmantdig)
1055 				commit = p;
1056 			break;
1057 		case S_FRAC:
1058 			if (((c == 'E' || c == 'e') && !ishex) ||
1059 			    ((c == 'P' || c == 'p') && ishex)) {
1060 				if (!gotmantdig)
1061 					goto parsedone;
1062 				else
1063 					state = S_EXP;
1064 			} else if ((ishex && isxdigit(c)) || isdigit(c)) {
1065 				commit = p;
1066 				gotmantdig = 1;
1067 			} else
1068 				goto parsedone;
1069 			break;
1070 		case S_EXP:
1071 			state = S_EXPDIGITS;
1072 			if (c == '-' || c == '+')
1073 				break;
1074 			else
1075 				goto reswitch;
1076 		case S_EXPDIGITS:
1077 			if (isdigit(c))
1078 				commit = p;
1079 			else
1080 				goto parsedone;
1081 			break;
1082 		default:
1083 			abort();
1084 		}
1085 		*p++ = c;
1086 		if (--fp->_r > 0)
1087 			fp->_p++;
1088 		else if (__srefill(fp))
1089 			break;	/* EOF */
1090 	}
1091 
1092 parsedone:
1093 	while (commit < --p)
1094 		(void)ungetc(*(u_char *)p, fp);
1095 	*++commit = '\0';
1096 	return commit - buf;
1097 }
1098 #endif
1099