xref: /freebsd/lib/libc/stdio/vfscanf.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Copyright (c) 2011 The FreeBSD Foundation
6  * All rights reserved.
7  * Portions of this software were developed by David Chisnall
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * This code is derived from software contributed to Berkeley by
11  * Chris Torek.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. 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 #if defined(LIBC_SCCS) && !defined(lint)
39 static char sccsid[] = "@(#)vfscanf.c	8.1 (Berkeley) 6/4/93";
40 #endif /* LIBC_SCCS and not lint */
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include "namespace.h"
45 #include <ctype.h>
46 #include <inttypes.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <stddef.h>
50 #include <stdarg.h>
51 #include <string.h>
52 #include <wchar.h>
53 #include <wctype.h>
54 #include "un-namespace.h"
55 
56 #include "collate.h"
57 #include "libc_private.h"
58 #include "local.h"
59 #include "xlocale_private.h"
60 
61 #ifndef NO_FLOATING_POINT
62 #include <locale.h>
63 #endif
64 
65 #define	BUF		513	/* Maximum length of numeric string. */
66 
67 /*
68  * Flags used during conversion.
69  */
70 #define	LONG		0x01	/* l: long or double */
71 #define	LONGDBL		0x02	/* L: long double */
72 #define	SHORT		0x04	/* h: short */
73 #define	SUPPRESS	0x08	/* *: suppress assignment */
74 #define	POINTER		0x10	/* p: void * (as hex) */
75 #define	NOSKIP		0x20	/* [ or c: do not skip blanks */
76 #define	LONGLONG	0x400	/* ll: long long (+ deprecated q: quad) */
77 #define	INTMAXT		0x800	/* j: intmax_t */
78 #define	PTRDIFFT	0x1000	/* t: ptrdiff_t */
79 #define	SIZET		0x2000	/* z: size_t */
80 #define	SHORTSHORT	0x4000	/* hh: char */
81 #define	UNSIGNED	0x8000	/* %[oupxX] conversions */
82 
83 /*
84  * The following are used in integral conversions only:
85  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS
86  */
87 #define	SIGNOK		0x40	/* +/- is (still) legal */
88 #define	NDIGITS		0x80	/* no digits detected */
89 #define	PFXOK		0x100	/* 0x prefix is (still) legal */
90 #define	NZDIGITS	0x200	/* no zero digits detected */
91 #define	HAVESIGN	0x10000	/* sign detected */
92 
93 /*
94  * Conversion types.
95  */
96 #define	CT_CHAR		0	/* %c conversion */
97 #define	CT_CCL		1	/* %[...] conversion */
98 #define	CT_STRING	2	/* %s conversion */
99 #define	CT_INT		3	/* %[dioupxX] conversion */
100 #define	CT_FLOAT	4	/* %[efgEFG] conversion */
101 
102 static const u_char *__sccl(char *, const u_char *);
103 #ifndef NO_FLOATING_POINT
104 static int parsefloat(FILE *, char *, char *, locale_t);
105 #endif
106 
107 __weak_reference(__vfscanf, vfscanf);
108 
109 /*
110  * Conversion functions are passed a pointer to this object instead of
111  * a real parameter to indicate that the assignment-suppression (*)
112  * flag was specified.  We could use a NULL pointer to indicate this,
113  * but that would mask bugs in applications that call scanf() with a
114  * NULL pointer.
115  */
116 static const int suppress;
117 #define	SUPPRESS_PTR	((void *)&suppress)
118 
119 static const mbstate_t initial_mbs;
120 
121 /*
122  * The following conversion functions return the number of characters consumed,
123  * or -1 on input failure.  Character class conversion returns 0 on match
124  * failure.
125  */
126 
127 static __inline int
128 convert_char(FILE *fp, char * p, int width)
129 {
130 	int n;
131 
132 	if (p == SUPPRESS_PTR) {
133 		size_t sum = 0;
134 		for (;;) {
135 			if ((n = fp->_r) < width) {
136 				sum += n;
137 				width -= n;
138 				fp->_p += n;
139 				if (__srefill(fp)) {
140 					if (sum == 0)
141 						return (-1);
142 					break;
143 				}
144 			} else {
145 				sum += width;
146 				fp->_r -= width;
147 				fp->_p += width;
148 				break;
149 			}
150 		}
151 		return (sum);
152 	} else {
153 		size_t r = __fread(p, 1, width, fp);
154 
155 		if (r == 0)
156 			return (-1);
157 		return (r);
158 	}
159 }
160 
161 static __inline int
162 convert_wchar(FILE *fp, wchar_t *wcp, int width, locale_t locale)
163 {
164 	mbstate_t mbs;
165 	int n, nread;
166 	wint_t wi;
167 
168 	mbs = initial_mbs;
169 	n = 0;
170 	while (width-- != 0 &&
171 	    (wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF) {
172 		if (wcp != SUPPRESS_PTR)
173 			*wcp++ = (wchar_t)wi;
174 		n += nread;
175 	}
176 	if (n == 0)
177 		return (-1);
178 	return (n);
179 }
180 
181 static __inline int
182 convert_ccl(FILE *fp, char * p, int width, const char *ccltab)
183 {
184 	char *p0;
185 	int n;
186 
187 	if (p == SUPPRESS_PTR) {
188 		n = 0;
189 		while (ccltab[*fp->_p]) {
190 			n++, fp->_r--, fp->_p++;
191 			if (--width == 0)
192 				break;
193 			if (fp->_r <= 0 && __srefill(fp)) {
194 				if (n == 0)
195 					return (-1);
196 				break;
197 			}
198 		}
199 	} else {
200 		p0 = p;
201 		while (ccltab[*fp->_p]) {
202 			fp->_r--;
203 			*p++ = *fp->_p++;
204 			if (--width == 0)
205 				break;
206 			if (fp->_r <= 0 && __srefill(fp)) {
207 				if (p == p0)
208 					return (-1);
209 				break;
210 			}
211 		}
212 		n = p - p0;
213 		if (n == 0)
214 			return (0);
215 		*p = 0;
216 	}
217 	return (n);
218 }
219 
220 static __inline int
221 convert_wccl(FILE *fp, wchar_t *wcp, int width, const char *ccltab,
222     locale_t locale)
223 {
224 	mbstate_t mbs;
225 	wint_t wi;
226 	int n, nread;
227 
228 	mbs = initial_mbs;
229 	n = 0;
230 	if (wcp == SUPPRESS_PTR) {
231 		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
232 		    width-- != 0 && ccltab[wctob(wi)])
233 			n += nread;
234 		if (wi != WEOF)
235 			__ungetwc(wi, fp, __get_locale());
236 	} else {
237 		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
238 		    width-- != 0 && ccltab[wctob(wi)]) {
239 			*wcp++ = (wchar_t)wi;
240 			n += nread;
241 		}
242 		if (wi != WEOF)
243 			__ungetwc(wi, fp, __get_locale());
244 		if (n == 0)
245 			return (0);
246 		*wcp = 0;
247 	}
248 	return (n);
249 }
250 
251 static __inline int
252 convert_string(FILE *fp, char * p, int width)
253 {
254 	char *p0;
255 	int n;
256 
257 	if (p == SUPPRESS_PTR) {
258 		n = 0;
259 		while (!isspace(*fp->_p)) {
260 			n++, fp->_r--, fp->_p++;
261 			if (--width == 0)
262 				break;
263 			if (fp->_r <= 0 && __srefill(fp))
264 				break;
265 		}
266 	} else {
267 		p0 = p;
268 		while (!isspace(*fp->_p)) {
269 			fp->_r--;
270 			*p++ = *fp->_p++;
271 			if (--width == 0)
272 				break;
273 			if (fp->_r <= 0 && __srefill(fp))
274 				break;
275 		}
276 		*p = 0;
277 		n = p - p0;
278 	}
279 	return (n);
280 }
281 
282 static __inline int
283 convert_wstring(FILE *fp, wchar_t *wcp, int width, locale_t locale)
284 {
285 	mbstate_t mbs;
286 	wint_t wi;
287 	int n, nread;
288 
289 	mbs = initial_mbs;
290 	n = 0;
291 	if (wcp == SUPPRESS_PTR) {
292 		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
293 		    width-- != 0 && !iswspace(wi))
294 			n += nread;
295 		if (wi != WEOF)
296 			__ungetwc(wi, fp, __get_locale());
297 	} else {
298 		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
299 		    width-- != 0 && !iswspace(wi)) {
300 			*wcp++ = (wchar_t)wi;
301 			n += nread;
302 		}
303 		if (wi != WEOF)
304 			__ungetwc(wi, fp, __get_locale());
305 		*wcp = '\0';
306 	}
307 	return (n);
308 }
309 
310 /*
311  * Read an integer, storing it in buf.  The only relevant bit in the
312  * flags argument is PFXOK.
313  *
314  * Return 0 on a match failure, and the number of characters read
315  * otherwise.
316  */
317 static __inline int
318 parseint(FILE *fp, char * __restrict buf, int width, int base, int flags)
319 {
320 	/* `basefix' is used to avoid `if' tests */
321 	static const short basefix[17] =
322 		{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
323 	char *p;
324 	int c;
325 
326 	flags |= SIGNOK | NDIGITS | NZDIGITS;
327 	for (p = buf; width; width--) {
328 		c = *fp->_p;
329 		/*
330 		 * Switch on the character; `goto ok' if we accept it
331 		 * as a part of number.
332 		 */
333 		switch (c) {
334 
335 		/*
336 		 * The digit 0 is always legal, but is special.  For
337 		 * %i conversions, if no digits (zero or nonzero) have
338 		 * been scanned (only signs), we will have base==0.
339 		 * In that case, we should set it to 8 and enable 0x
340 		 * prefixing.  Also, if we have not scanned zero
341 		 * digits before this, do not turn off prefixing
342 		 * (someone else will turn it off if we have scanned
343 		 * any nonzero digits).
344 		 */
345 		case '0':
346 			if (base == 0) {
347 				base = 8;
348 				flags |= PFXOK;
349 			}
350 			if (flags & NZDIGITS)
351 				flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
352 			else
353 				flags &= ~(SIGNOK|PFXOK|NDIGITS);
354 			goto ok;
355 
356 		/* 1 through 7 always legal */
357 		case '1': case '2': case '3':
358 		case '4': case '5': case '6': case '7':
359 			base = basefix[base];
360 			flags &= ~(SIGNOK | PFXOK | NDIGITS);
361 			goto ok;
362 
363 		/* digits 8 and 9 ok iff decimal or hex */
364 		case '8': case '9':
365 			base = basefix[base];
366 			if (base <= 8)
367 				break;	/* not legal here */
368 			flags &= ~(SIGNOK | PFXOK | NDIGITS);
369 			goto ok;
370 
371 		/* letters ok iff hex */
372 		case 'A': case 'B': case 'C':
373 		case 'D': case 'E': case 'F':
374 		case 'a': case 'b': case 'c':
375 		case 'd': case 'e': case 'f':
376 			/* no need to fix base here */
377 			if (base <= 10)
378 				break;	/* not legal here */
379 			flags &= ~(SIGNOK | PFXOK | NDIGITS);
380 			goto ok;
381 
382 		/* sign ok only as first character */
383 		case '+': case '-':
384 			if (flags & SIGNOK) {
385 				flags &= ~SIGNOK;
386 				flags |= HAVESIGN;
387 				goto ok;
388 			}
389 			break;
390 
391 		/*
392 		 * x ok iff flag still set & 2nd char (or 3rd char if
393 		 * we have a sign).
394 		 */
395 		case 'x': case 'X':
396 			if (flags & PFXOK && p ==
397 			    buf + 1 + !!(flags & HAVESIGN)) {
398 				base = 16;	/* if %i */
399 				flags &= ~PFXOK;
400 				goto ok;
401 			}
402 			break;
403 		}
404 
405 		/*
406 		 * If we got here, c is not a legal character for a
407 		 * number.  Stop accumulating digits.
408 		 */
409 		break;
410 	ok:
411 		/*
412 		 * c is legal: store it and look at the next.
413 		 */
414 		*p++ = c;
415 		if (--fp->_r > 0)
416 			fp->_p++;
417 		else if (__srefill(fp))
418 			break;		/* EOF */
419 	}
420 	/*
421 	 * If we had only a sign, it is no good; push back the sign.
422 	 * If the number ends in `x', it was [sign] '0' 'x', so push
423 	 * back the x and treat it as [sign] '0'.
424 	 */
425 	if (flags & NDIGITS) {
426 		if (p > buf)
427 			(void) __ungetc(*(u_char *)--p, fp);
428 		return (0);
429 	}
430 	c = ((u_char *)p)[-1];
431 	if (c == 'x' || c == 'X') {
432 		--p;
433 		(void) __ungetc(c, fp);
434 	}
435 	return (p - buf);
436 }
437 
438 /*
439  * __vfscanf - MT-safe version
440  */
441 int
442 __vfscanf(FILE *fp, char const *fmt0, va_list ap)
443 {
444 	int ret;
445 
446 	FLOCKFILE(fp);
447 	ret = __svfscanf(fp, __get_locale(), fmt0, ap);
448 	FUNLOCKFILE(fp);
449 	return (ret);
450 }
451 int
452 vfscanf_l(FILE *fp, locale_t locale, char const *fmt0, va_list ap)
453 {
454 	int ret;
455 	FIX_LOCALE(locale);
456 
457 	FLOCKFILE(fp);
458 	ret = __svfscanf(fp, locale, fmt0, ap);
459 	FUNLOCKFILE(fp);
460 	return (ret);
461 }
462 
463 /*
464  * __svfscanf - non-MT-safe version of __vfscanf
465  */
466 int
467 __svfscanf(FILE *fp, locale_t locale, const char *fmt0, va_list ap)
468 {
469 #define	GETARG(type)	((flags & SUPPRESS) ? SUPPRESS_PTR : va_arg(ap, type))
470 	const u_char *fmt = (const u_char *)fmt0;
471 	int c;			/* character from format, or conversion */
472 	size_t width;		/* field width, or 0 */
473 	int flags;		/* flags as defined above */
474 	int nassigned;		/* number of fields assigned */
475 	int nconversions;	/* number of conversions */
476 	int nr;			/* characters read by the current conversion */
477 	int nread;		/* number of characters consumed from fp */
478 	int base;		/* base argument to conversion function */
479 	char ccltab[256];	/* character class table for %[...] */
480 	char buf[BUF];		/* buffer for numeric conversions */
481 
482 	ORIENT(fp, -1);
483 
484 	nassigned = 0;
485 	nconversions = 0;
486 	nread = 0;
487 	for (;;) {
488 		c = *fmt++;
489 		if (c == 0)
490 			return (nassigned);
491 		if (isspace(c)) {
492 			while ((fp->_r > 0 || __srefill(fp) == 0) && isspace(*fp->_p))
493 				nread++, fp->_r--, fp->_p++;
494 			continue;
495 		}
496 		if (c != '%')
497 			goto literal;
498 		width = 0;
499 		flags = 0;
500 		/*
501 		 * switch on the format.  continue if done;
502 		 * break once format type is derived.
503 		 */
504 again:		c = *fmt++;
505 		switch (c) {
506 		case '%':
507 literal:
508 			if (fp->_r <= 0 && __srefill(fp))
509 				goto input_failure;
510 			if (*fp->_p != c)
511 				goto match_failure;
512 			fp->_r--, fp->_p++;
513 			nread++;
514 			continue;
515 
516 		case '*':
517 			flags |= SUPPRESS;
518 			goto again;
519 		case 'j':
520 			flags |= INTMAXT;
521 			goto again;
522 		case 'l':
523 			if (flags & LONG) {
524 				flags &= ~LONG;
525 				flags |= LONGLONG;
526 			} else
527 				flags |= LONG;
528 			goto again;
529 		case 'q':
530 			flags |= LONGLONG;	/* not quite */
531 			goto again;
532 		case 't':
533 			flags |= PTRDIFFT;
534 			goto again;
535 		case 'z':
536 			flags |= SIZET;
537 			goto again;
538 		case 'L':
539 			flags |= LONGDBL;
540 			goto again;
541 		case 'h':
542 			if (flags & SHORT) {
543 				flags &= ~SHORT;
544 				flags |= SHORTSHORT;
545 			} else
546 				flags |= SHORT;
547 			goto again;
548 
549 		case '0': case '1': case '2': case '3': case '4':
550 		case '5': case '6': case '7': case '8': case '9':
551 			width = width * 10 + c - '0';
552 			goto again;
553 
554 		/*
555 		 * Conversions.
556 		 */
557 		case 'd':
558 			c = CT_INT;
559 			base = 10;
560 			break;
561 
562 		case 'i':
563 			c = CT_INT;
564 			base = 0;
565 			break;
566 
567 		case 'o':
568 			c = CT_INT;
569 			flags |= UNSIGNED;
570 			base = 8;
571 			break;
572 
573 		case 'u':
574 			c = CT_INT;
575 			flags |= UNSIGNED;
576 			base = 10;
577 			break;
578 
579 		case 'X':
580 		case 'x':
581 			flags |= PFXOK;	/* enable 0x prefixing */
582 			c = CT_INT;
583 			flags |= UNSIGNED;
584 			base = 16;
585 			break;
586 
587 #ifndef NO_FLOATING_POINT
588 		case 'A': case 'E': case 'F': case 'G':
589 		case 'a': case 'e': case 'f': case 'g':
590 			c = CT_FLOAT;
591 			break;
592 #endif
593 
594 		case 'S':
595 			flags |= LONG;
596 			/* FALLTHROUGH */
597 		case 's':
598 			c = CT_STRING;
599 			break;
600 
601 		case '[':
602 			fmt = __sccl(ccltab, fmt);
603 			flags |= NOSKIP;
604 			c = CT_CCL;
605 			break;
606 
607 		case 'C':
608 			flags |= LONG;
609 			/* FALLTHROUGH */
610 		case 'c':
611 			flags |= NOSKIP;
612 			c = CT_CHAR;
613 			break;
614 
615 		case 'p':	/* pointer format is like hex */
616 			flags |= POINTER | PFXOK;
617 			c = CT_INT;		/* assumes sizeof(uintmax_t) */
618 			flags |= UNSIGNED;	/*      >= sizeof(uintptr_t) */
619 			base = 16;
620 			break;
621 
622 		case 'n':
623 			if (flags & SUPPRESS)	/* ??? */
624 				continue;
625 			if (flags & SHORTSHORT)
626 				*va_arg(ap, char *) = nread;
627 			else if (flags & SHORT)
628 				*va_arg(ap, short *) = nread;
629 			else if (flags & LONG)
630 				*va_arg(ap, long *) = nread;
631 			else if (flags & LONGLONG)
632 				*va_arg(ap, long long *) = nread;
633 			else if (flags & INTMAXT)
634 				*va_arg(ap, intmax_t *) = nread;
635 			else if (flags & SIZET)
636 				*va_arg(ap, size_t *) = nread;
637 			else if (flags & PTRDIFFT)
638 				*va_arg(ap, ptrdiff_t *) = nread;
639 			else
640 				*va_arg(ap, int *) = nread;
641 			continue;
642 
643 		default:
644 			goto match_failure;
645 
646 		/*
647 		 * Disgusting backwards compatibility hack.	XXX
648 		 */
649 		case '\0':	/* compat */
650 			return (EOF);
651 		}
652 
653 		/*
654 		 * We have a conversion that requires input.
655 		 */
656 		if (fp->_r <= 0 && __srefill(fp))
657 			goto input_failure;
658 
659 		/*
660 		 * Consume leading white space, except for formats
661 		 * that suppress this.
662 		 */
663 		if ((flags & NOSKIP) == 0) {
664 			while (isspace(*fp->_p)) {
665 				nread++;
666 				if (--fp->_r > 0)
667 					fp->_p++;
668 				else if (__srefill(fp))
669 					goto input_failure;
670 			}
671 			/*
672 			 * Note that there is at least one character in
673 			 * the buffer, so conversions that do not set NOSKIP
674 			 * ca no longer result in an input failure.
675 			 */
676 		}
677 
678 		/*
679 		 * Do the conversion.
680 		 */
681 		switch (c) {
682 
683 		case CT_CHAR:
684 			/* scan arbitrary characters (sets NOSKIP) */
685 			if (width == 0)
686 				width = 1;
687 			if (flags & LONG) {
688 				nr = convert_wchar(fp, GETARG(wchar_t *),
689 				    width, locale);
690 			} else {
691 				nr = convert_char(fp, GETARG(char *), width);
692 			}
693 			if (nr < 0)
694 				goto input_failure;
695 			break;
696 
697 		case CT_CCL:
698 			/* scan a (nonempty) character class (sets NOSKIP) */
699 			if (width == 0)
700 				width = (size_t)~0;	/* `infinity' */
701 			if (flags & LONG) {
702 				nr = convert_wccl(fp, GETARG(wchar_t *), width,
703 				    ccltab, locale);
704 			} else {
705 				nr = convert_ccl(fp, GETARG(char *), width,
706 				    ccltab);
707 			}
708 			if (nr <= 0) {
709 				if (nr < 0)
710 					goto input_failure;
711 				else /* nr == 0 */
712 					goto match_failure;
713 			}
714 			break;
715 
716 		case CT_STRING:
717 			/* like CCL, but zero-length string OK, & no NOSKIP */
718 			if (width == 0)
719 				width = (size_t)~0;
720 			if (flags & LONG) {
721 				nr = convert_wstring(fp, GETARG(wchar_t *),
722 				    width, locale);
723 			} else {
724 				nr = convert_string(fp, GETARG(char *), width);
725 			}
726 			if (nr < 0)
727 				goto input_failure;
728 			break;
729 
730 		case CT_INT:
731 			/* scan an integer as if by the conversion function */
732 #ifdef hardway
733 			if (width == 0 || width > sizeof(buf) - 1)
734 				width = sizeof(buf) - 1;
735 #else
736 			/* size_t is unsigned, hence this optimisation */
737 			if (--width > sizeof(buf) - 2)
738 				width = sizeof(buf) - 2;
739 			width++;
740 #endif
741 			nr = parseint(fp, buf, width, base, flags);
742 			if (nr == 0)
743 				goto match_failure;
744 			if ((flags & SUPPRESS) == 0) {
745 				uintmax_t res;
746 
747 				buf[nr] = '\0';
748 				if ((flags & UNSIGNED) == 0)
749 				    res = strtoimax_l(buf, (char **)NULL, base, locale);
750 				else
751 				    res = strtoumax_l(buf, (char **)NULL, base, locale);
752 				if (flags & POINTER)
753 					*va_arg(ap, void **) =
754 							(void *)(uintptr_t)res;
755 				else if (flags & SHORTSHORT)
756 					*va_arg(ap, char *) = res;
757 				else if (flags & SHORT)
758 					*va_arg(ap, short *) = res;
759 				else if (flags & LONG)
760 					*va_arg(ap, long *) = res;
761 				else if (flags & LONGLONG)
762 					*va_arg(ap, long long *) = res;
763 				else if (flags & INTMAXT)
764 					*va_arg(ap, intmax_t *) = res;
765 				else if (flags & PTRDIFFT)
766 					*va_arg(ap, ptrdiff_t *) = res;
767 				else if (flags & SIZET)
768 					*va_arg(ap, size_t *) = res;
769 				else
770 					*va_arg(ap, int *) = res;
771 			}
772 			break;
773 
774 #ifndef NO_FLOATING_POINT
775 		case CT_FLOAT:
776 			/* scan a floating point number as if by strtod */
777 			if (width == 0 || width > sizeof(buf) - 1)
778 				width = sizeof(buf) - 1;
779 			nr = parsefloat(fp, buf, buf + width, locale);
780 			if (nr == 0)
781 				goto match_failure;
782 			if ((flags & SUPPRESS) == 0) {
783 				if (flags & LONGDBL) {
784 					long double res = strtold_l(buf, NULL,
785 					    locale);
786 					*va_arg(ap, long double *) = res;
787 				} else if (flags & LONG) {
788 					double res = strtod_l(buf, NULL,
789 					    locale);
790 					*va_arg(ap, double *) = res;
791 				} else {
792 					float res = strtof_l(buf, NULL, locale);
793 					*va_arg(ap, float *) = res;
794 				}
795 			}
796 			break;
797 #endif /* !NO_FLOATING_POINT */
798 		}
799 		if (!(flags & SUPPRESS))
800 			nassigned++;
801 		nread += nr;
802 		nconversions++;
803 	}
804 input_failure:
805 	return (nconversions != 0 ? nassigned : EOF);
806 match_failure:
807 	return (nassigned);
808 }
809 
810 /*
811  * Fill in the given table from the scanset at the given format
812  * (just after `[').  Return a pointer to the character past the
813  * closing `]'.  The table has a 1 wherever characters should be
814  * considered part of the scanset.
815  */
816 static const u_char *
817 __sccl(char *tab, const u_char *fmt)
818 {
819 	int c, n, v, i;
820 	struct xlocale_collate *table =
821 		(struct xlocale_collate*)__get_locale()->components[XLC_COLLATE];
822 
823 	/* first `clear' the whole table */
824 	c = *fmt++;		/* first char hat => negated scanset */
825 	if (c == '^') {
826 		v = 1;		/* default => accept */
827 		c = *fmt++;	/* get new first char */
828 	} else
829 		v = 0;		/* default => reject */
830 
831 	/* XXX: Will not work if sizeof(tab*) > sizeof(char) */
832 	(void) memset(tab, v, 256);
833 
834 	if (c == 0)
835 		return (fmt - 1);/* format ended before closing ] */
836 
837 	/*
838 	 * Now set the entries corresponding to the actual scanset
839 	 * to the opposite of the above.
840 	 *
841 	 * The first character may be ']' (or '-') without being special;
842 	 * the last character may be '-'.
843 	 */
844 	v = 1 - v;
845 	for (;;) {
846 		tab[c] = v;		/* take character c */
847 doswitch:
848 		n = *fmt++;		/* and examine the next */
849 		switch (n) {
850 
851 		case 0:			/* format ended too soon */
852 			return (fmt - 1);
853 
854 		case '-':
855 			/*
856 			 * A scanset of the form
857 			 *	[01+-]
858 			 * is defined as `the digit 0, the digit 1,
859 			 * the character +, the character -', but
860 			 * the effect of a scanset such as
861 			 *	[a-zA-Z0-9]
862 			 * is implementation defined.  The V7 Unix
863 			 * scanf treats `a-z' as `the letters a through
864 			 * z', but treats `a-a' as `the letter a, the
865 			 * character -, and the letter a'.
866 			 *
867 			 * For compatibility, the `-' is not considered
868 			 * to define a range if the character following
869 			 * it is either a close bracket (required by ANSI)
870 			 * or is not numerically greater than the character
871 			 * we just stored in the table (c).
872 			 */
873 			n = *fmt;
874 			if (n == ']'
875 			    || (table->__collate_load_error ? n < c :
876 				__collate_range_cmp(n, c) < 0
877 			       )
878 			   ) {
879 				c = '-';
880 				break;	/* resume the for(;;) */
881 			}
882 			fmt++;
883 			/* fill in the range */
884 			if (table->__collate_load_error) {
885 				do {
886 					tab[++c] = v;
887 				} while (c < n);
888 			} else {
889 				for (i = 0; i < 256; i ++)
890 					if (__collate_range_cmp(c, i) <= 0 &&
891 					    __collate_range_cmp(i, n) <= 0
892 					   )
893 						tab[i] = v;
894 			}
895 #if 1	/* XXX another disgusting compatibility hack */
896 			c = n;
897 			/*
898 			 * Alas, the V7 Unix scanf also treats formats
899 			 * such as [a-c-e] as `the letters a through e'.
900 			 * This too is permitted by the standard....
901 			 */
902 			goto doswitch;
903 #else
904 			c = *fmt++;
905 			if (c == 0)
906 				return (fmt - 1);
907 			if (c == ']')
908 				return (fmt);
909 #endif
910 			break;
911 
912 		case ']':		/* end of scanset */
913 			return (fmt);
914 
915 		default:		/* just another character */
916 			c = n;
917 			break;
918 		}
919 	}
920 	/* NOTREACHED */
921 }
922 
923 #ifndef NO_FLOATING_POINT
924 static int
925 parsefloat(FILE *fp, char *buf, char *end, locale_t locale)
926 {
927 	char *commit, *p;
928 	int infnanpos = 0, decptpos = 0;
929 	enum {
930 		S_START, S_GOTSIGN, S_INF, S_NAN, S_DONE, S_MAYBEHEX,
931 		S_DIGITS, S_DECPT, S_FRAC, S_EXP, S_EXPDIGITS
932 	} state = S_START;
933 	unsigned char c;
934 	const char *decpt = localeconv_l(locale)->decimal_point;
935 	_Bool gotmantdig = 0, ishex = 0;
936 
937 	/*
938 	 * We set commit = p whenever the string we have read so far
939 	 * constitutes a valid representation of a floating point
940 	 * number by itself.  At some point, the parse will complete
941 	 * or fail, and we will ungetc() back to the last commit point.
942 	 * To ensure that the file offset gets updated properly, it is
943 	 * always necessary to read at least one character that doesn't
944 	 * match; thus, we can't short-circuit "infinity" or "nan(...)".
945 	 */
946 	commit = buf - 1;
947 	for (p = buf; p < end; ) {
948 		c = *fp->_p;
949 reswitch:
950 		switch (state) {
951 		case S_START:
952 			state = S_GOTSIGN;
953 			if (c == '-' || c == '+')
954 				break;
955 			else
956 				goto reswitch;
957 		case S_GOTSIGN:
958 			switch (c) {
959 			case '0':
960 				state = S_MAYBEHEX;
961 				commit = p;
962 				break;
963 			case 'I':
964 			case 'i':
965 				state = S_INF;
966 				break;
967 			case 'N':
968 			case 'n':
969 				state = S_NAN;
970 				break;
971 			default:
972 				state = S_DIGITS;
973 				goto reswitch;
974 			}
975 			break;
976 		case S_INF:
977 			if (infnanpos > 6 ||
978 			    (c != "nfinity"[infnanpos] &&
979 			     c != "NFINITY"[infnanpos]))
980 				goto parsedone;
981 			if (infnanpos == 1 || infnanpos == 6)
982 				commit = p;	/* inf or infinity */
983 			infnanpos++;
984 			break;
985 		case S_NAN:
986 			switch (infnanpos) {
987 			case 0:
988 				if (c != 'A' && c != 'a')
989 					goto parsedone;
990 				break;
991 			case 1:
992 				if (c != 'N' && c != 'n')
993 					goto parsedone;
994 				else
995 					commit = p;
996 				break;
997 			case 2:
998 				if (c != '(')
999 					goto parsedone;
1000 				break;
1001 			default:
1002 				if (c == ')') {
1003 					commit = p;
1004 					state = S_DONE;
1005 				} else if (!isalnum(c) && c != '_')
1006 					goto parsedone;
1007 				break;
1008 			}
1009 			infnanpos++;
1010 			break;
1011 		case S_DONE:
1012 			goto parsedone;
1013 		case S_MAYBEHEX:
1014 			state = S_DIGITS;
1015 			if (c == 'X' || c == 'x') {
1016 				ishex = 1;
1017 				break;
1018 			} else {	/* we saw a '0', but no 'x' */
1019 				gotmantdig = 1;
1020 				goto reswitch;
1021 			}
1022 		case S_DIGITS:
1023 			if ((ishex && isxdigit(c)) || isdigit(c)) {
1024 				gotmantdig = 1;
1025 				commit = p;
1026 				break;
1027 			} else {
1028 				state = S_DECPT;
1029 				goto reswitch;
1030 			}
1031 		case S_DECPT:
1032 			if (c == decpt[decptpos]) {
1033 				if (decpt[++decptpos] == '\0') {
1034 					/* We read the complete decpt seq. */
1035 					state = S_FRAC;
1036 					if (gotmantdig)
1037 						commit = p;
1038 				}
1039 				break;
1040 			} else if (!decptpos) {
1041 				/* We didn't read any decpt characters. */
1042 				state = S_FRAC;
1043 				goto reswitch;
1044 			} else {
1045 				/*
1046 				 * We read part of a multibyte decimal point,
1047 				 * but the rest is invalid, so bail.
1048 				 */
1049 				goto parsedone;
1050 			}
1051 		case S_FRAC:
1052 			if (((c == 'E' || c == 'e') && !ishex) ||
1053 			    ((c == 'P' || c == 'p') && ishex)) {
1054 				if (!gotmantdig)
1055 					goto parsedone;
1056 				else
1057 					state = S_EXP;
1058 			} else if ((ishex && isxdigit(c)) || isdigit(c)) {
1059 				commit = p;
1060 				gotmantdig = 1;
1061 			} else
1062 				goto parsedone;
1063 			break;
1064 		case S_EXP:
1065 			state = S_EXPDIGITS;
1066 			if (c == '-' || c == '+')
1067 				break;
1068 			else
1069 				goto reswitch;
1070 		case S_EXPDIGITS:
1071 			if (isdigit(c))
1072 				commit = p;
1073 			else
1074 				goto parsedone;
1075 			break;
1076 		default:
1077 			abort();
1078 		}
1079 		*p++ = c;
1080 		if (--fp->_r > 0)
1081 			fp->_p++;
1082 		else if (__srefill(fp))
1083 			break;	/* EOF */
1084 	}
1085 
1086 parsedone:
1087 	while (commit < --p)
1088 		__ungetc(*(u_char *)p, fp);
1089 	*++commit = '\0';
1090 	return (commit - buf);
1091 }
1092 #endif
1093