xref: /freebsd/lib/libc/stdio/vfwscanf.c (revision 224af215a6fe8d5e5e2c91cc97c48bdd67c991c7)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Chris Torek.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 #if 0
39 #if defined(LIBC_SCCS) && !defined(lint)
40 static char sccsid[] = "@(#)vfscanf.c	8.1 (Berkeley) 6/4/93";
41 #endif /* LIBC_SCCS and not lint */
42 __FBSDID("FreeBSD: src/lib/libc/stdio/vfscanf.c,v 1.24 2002/08/13 09:30:41 tjr Exp ");
43 #endif
44 __FBSDID("$FreeBSD$");
45 
46 #include "namespace.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 #include "un-namespace.h"
57 
58 #include "libc_private.h"
59 #include "local.h"
60 
61 #define FLOATING_POINT
62 
63 #ifdef FLOATING_POINT
64 #include <locale.h>
65 #include "floatio.h"
66 #endif
67 
68 #define	BUF		513	/* Maximum length of numeric string. */
69 
70 /*
71  * Flags used during conversion.
72  */
73 #define	LONG		0x01	/* l: long or double */
74 #define	LONGDBL		0x02	/* L: long double */
75 #define	SHORT		0x04	/* h: short */
76 #define	SUPPRESS	0x08	/* *: suppress assignment */
77 #define	POINTER		0x10	/* p: void * (as hex) */
78 #define	NOSKIP		0x20	/* [ or c: do not skip blanks */
79 #define	LONGLONG	0x400	/* ll: long long (+ deprecated q: quad) */
80 #define	INTMAXT		0x800	/* j: intmax_t */
81 #define	PTRDIFFT	0x1000	/* t: ptrdiff_t */
82 #define	SIZET		0x2000	/* z: size_t */
83 #define	SHORTSHORT	0x4000	/* hh: char */
84 #define	UNSIGNED	0x8000	/* %[oupxX] conversions */
85 
86 /*
87  * The following are used in numeric conversions only:
88  * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
89  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
90  */
91 #define	SIGNOK		0x40	/* +/- is (still) legal */
92 #define	NDIGITS		0x80	/* no digits detected */
93 
94 #define	DPTOK		0x100	/* (float) decimal point is still legal */
95 #define	EXPOK		0x200	/* (float) exponent (e+3, etc) still legal */
96 
97 #define	PFXOK		0x100	/* 0x prefix is (still) legal */
98 #define	NZDIGITS	0x200	/* no zero digits detected */
99 
100 /*
101  * Conversion types.
102  */
103 #define	CT_CHAR		0	/* %c conversion */
104 #define	CT_CCL		1	/* %[...] conversion */
105 #define	CT_STRING	2	/* %s conversion */
106 #define	CT_INT		3	/* %[dioupxX] conversion */
107 #define	CT_FLOAT	4	/* %[efgEFG] conversion */
108 
109 #define	INCCL(_c)	\
110 	(cclcompl ? (wmemchr(ccls, (_c), ccle - ccls) == NULL) : \
111 	(wmemchr(ccls, (_c), ccle - ccls) != NULL))
112 
113 /*
114  * MT-safe version.
115  */
116 int
117 vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap)
118 {
119 	int ret;
120 
121 	FLOCKFILE(fp);
122 	ORIENT(fp, 1);
123 	ret = __vfwscanf(fp, fmt, ap);
124 	FUNLOCKFILE(fp);
125 	return (ret);
126 }
127 
128 /*
129  * Non-MT-safe version.
130  */
131 int
132 __vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap)
133 {
134 	wint_t c;		/* character from format, or conversion */
135 	size_t width;		/* field width, or 0 */
136 	wchar_t *p;		/* points into all kinds of strings */
137 	int n;			/* handy integer */
138 	int flags;		/* flags as defined above */
139 	wchar_t *p0;		/* saves original value of p when necessary */
140 	int nassigned;		/* number of fields assigned */
141 	int nconversions;	/* number of conversions */
142 	int nread;		/* number of characters consumed from fp */
143 	int base;		/* base argument to conversion function */
144 	wchar_t buf[BUF];	/* buffer for numeric conversions */
145 	const wchar_t *ccls;	/* character class start */
146 	const wchar_t *ccle;	/* character class end */
147 	int cclcompl;		/* ccl is complemented? */
148 	wint_t wi;		/* handy wint_t */
149 	char *mbp;		/* multibyte string pointer for %c %s %[ */
150 	size_t nconv;		/* number of bytes in mb. conversion */
151 	mbstate_t mbs;		/* multibyte state */
152 
153 	/* `basefix' is used to avoid `if' tests in the integer scanner */
154 	static short basefix[17] =
155 		{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
156 #ifdef FLOATING_POINT
157 	char decimal_point = localeconv()->decimal_point[0];
158 #endif
159 
160 	nassigned = 0;
161 	nconversions = 0;
162 	nread = 0;
163 	ccls = ccle = NULL;
164 	for (;;) {
165 		c = *fmt++;
166 		if (c == 0)
167 			return (nassigned);
168 		if (iswspace(c)) {
169 			while ((c = __fgetwc(fp)) != WEOF &&
170 			    iswspace(c))
171 				;
172 			if (c != WEOF)
173 				__ungetwc(c, fp);
174 			continue;
175 		}
176 		if (c != '%')
177 			goto literal;
178 		width = 0;
179 		flags = 0;
180 		/*
181 		 * switch on the format.  continue if done;
182 		 * break once format type is derived.
183 		 */
184 again:		c = *fmt++;
185 		switch (c) {
186 		case '%':
187 literal:
188 			if ((wi = __fgetwc(fp)) == WEOF)
189 				goto input_failure;
190 			if (wi != c) {
191 				__ungetwc(wi, fp);
192 				goto input_failure;
193 			}
194 			nread++;
195 			continue;
196 
197 		case '*':
198 			flags |= SUPPRESS;
199 			goto again;
200 		case 'j':
201 			flags |= INTMAXT;
202 			goto again;
203 		case 'l':
204 			if (flags & LONG) {
205 				flags &= ~LONG;
206 				flags |= LONGLONG;
207 			} else
208 				flags |= LONG;
209 			goto again;
210 		case 'q':
211 			flags |= LONGLONG;	/* not quite */
212 			goto again;
213 		case 't':
214 			flags |= PTRDIFFT;
215 			goto again;
216 		case 'z':
217 			flags |= SIZET;
218 			goto again;
219 		case 'L':
220 			flags |= LONGDBL;
221 			goto again;
222 		case 'h':
223 			if (flags & SHORT) {
224 				flags &= ~SHORT;
225 				flags |= SHORTSHORT;
226 			} else
227 				flags |= SHORT;
228 			goto again;
229 
230 		case '0': case '1': case '2': case '3': case '4':
231 		case '5': case '6': case '7': case '8': case '9':
232 			width = width * 10 + c - '0';
233 			goto again;
234 
235 		/*
236 		 * Conversions.
237 		 */
238 		case 'd':
239 			c = CT_INT;
240 			base = 10;
241 			break;
242 
243 		case 'i':
244 			c = CT_INT;
245 			base = 0;
246 			break;
247 
248 		case 'o':
249 			c = CT_INT;
250 			flags |= UNSIGNED;
251 			base = 8;
252 			break;
253 
254 		case 'u':
255 			c = CT_INT;
256 			flags |= UNSIGNED;
257 			base = 10;
258 			break;
259 
260 		case 'X':
261 		case 'x':
262 			flags |= PFXOK;	/* enable 0x prefixing */
263 			c = CT_INT;
264 			flags |= UNSIGNED;
265 			base = 16;
266 			break;
267 
268 #ifdef FLOATING_POINT
269 		case 'E': case 'F': case 'G':
270 		case 'e': case 'f': case 'g':
271 			c = CT_FLOAT;
272 			break;
273 #endif
274 
275 		case 'S':
276 			flags |= LONG;
277 			/* FALLTHROUGH */
278 		case 's':
279 			c = CT_STRING;
280 			break;
281 
282 		case '[':
283 			ccls = fmt;
284 			if (*fmt == '^') {
285 				cclcompl = 1;
286 				fmt++;
287 			} else
288 				cclcompl = 0;
289 			if (*fmt == ']')
290 				fmt++;
291 			while (*fmt != '\0' && *fmt != ']')
292 				fmt++;
293 			ccle = fmt;
294 			fmt++;
295 			flags |= NOSKIP;
296 			c = CT_CCL;
297 			break;
298 
299 		case 'C':
300 			flags |= LONG;
301 			/* FALLTHROUGH */
302 		case 'c':
303 			flags |= NOSKIP;
304 			c = CT_CHAR;
305 			break;
306 
307 		case 'p':	/* pointer format is like hex */
308 			flags |= POINTER | PFXOK;
309 			c = CT_INT;		/* assumes sizeof(uintmax_t) */
310 			flags |= UNSIGNED;	/*      >= sizeof(uintptr_t) */
311 			base = 16;
312 			break;
313 
314 		case 'n':
315 			nconversions++;
316 			if (flags & SUPPRESS)	/* ??? */
317 				continue;
318 			if (flags & SHORTSHORT)
319 				*va_arg(ap, char *) = nread;
320 			else if (flags & SHORT)
321 				*va_arg(ap, short *) = nread;
322 			else if (flags & LONG)
323 				*va_arg(ap, long *) = nread;
324 			else if (flags & LONGLONG)
325 				*va_arg(ap, long long *) = nread;
326 			else if (flags & INTMAXT)
327 				*va_arg(ap, intmax_t *) = nread;
328 			else if (flags & SIZET)
329 				*va_arg(ap, size_t *) = nread;
330 			else if (flags & PTRDIFFT)
331 				*va_arg(ap, ptrdiff_t *) = nread;
332 			else
333 				*va_arg(ap, int *) = nread;
334 			continue;
335 
336 		default:
337 			goto match_failure;
338 
339 		/*
340 		 * Disgusting backwards compatibility hack.	XXX
341 		 */
342 		case '\0':	/* compat */
343 			return (EOF);
344 		}
345 
346 		/*
347 		 * Consume leading white space, except for formats
348 		 * that suppress this.
349 		 */
350 		if ((flags & NOSKIP) == 0) {
351 			while ((wi = __fgetwc(fp)) != WEOF && iswspace(wi))
352 				nread++;
353 			if (wi == WEOF)
354 				goto input_failure;
355 			__ungetwc(wi, fp);
356 		}
357 
358 		/*
359 		 * Do the conversion.
360 		 */
361 		switch (c) {
362 
363 		case CT_CHAR:
364 			/* scan arbitrary characters (sets NOSKIP) */
365 			if (width == 0)
366 				width = 1;
367 			if (flags & SUPPRESS) {
368 				while (width-- != 0 &&
369 				    (wi = __fgetwc(fp)) != WEOF)
370 					nread++;
371 			} else if (flags & LONG) {
372 				p = va_arg(ap, wchar_t *);
373 				n = 0;
374 				while (width-- != 0 &&
375 				    (wi = __fgetwc(fp)) != WEOF) {
376 					*p++ = (wchar_t)wi;
377 					n++;
378 				}
379 				if (n == 0)
380 					goto input_failure;
381 				nread += n;
382 				nassigned++;
383 			} else {
384 				mbp = va_arg(ap, char *);
385 				n = 0;
386 				memset(&mbs, 0, sizeof(mbs));
387 				while (width-- != 0 &&
388 				    (wi = __fgetwc(fp)) != WEOF) {
389 					nconv = wcrtomb(mbp, wi, &mbs);
390 					if (nconv == (size_t)-1)
391 						goto input_failure;
392 					mbp += nconv;
393 					n++;
394 				}
395 				if (n == 0)
396 					goto input_failure;
397 				nread += n;
398 				nassigned++;
399 			}
400 			nconversions++;
401 			break;
402 
403 		case CT_CCL:
404 			/* scan a (nonempty) character class (sets NOSKIP) */
405 			if (width == 0)
406 				width = (size_t)~0;	/* `infinity' */
407 			/* take only those things in the class */
408 			if (flags & SUPPRESS) {
409 				n = 0;
410 				while ((wi = __fgetwc(fp)) != WEOF &&
411 				    width-- != 0 && INCCL(wi))
412 					n++;
413 				if (wi != WEOF)
414 					__ungetwc(wi, fp);
415 				if (n == 0)
416 					goto match_failure;
417 			} else if (flags & LONG) {
418 				p0 = p = va_arg(ap, wchar_t *);
419 				while ((wi = __fgetwc(fp)) != WEOF &&
420 				    width-- != 0 && INCCL(wi))
421 					*p++ = (wchar_t)wi;
422 				if (wi != WEOF)
423 					__ungetwc(wi, fp);
424 				n = p - p0;
425 				if (n == 0)
426 					goto match_failure;
427 				*p = 0;
428 				nassigned++;
429 			} else {
430 				mbp = va_arg(ap, char *);
431 				n = 0;
432 				memset(&mbs, 0, sizeof(mbs));
433 				while ((wi = __fgetwc(fp)) != WEOF &&
434 				    width-- != 0 && INCCL(wi)) {
435 					nconv = wcrtomb(mbp, wi, &mbs);
436 					if (nconv == (size_t)-1)
437 						goto input_failure;
438 					mbp += nconv;
439 					n++;
440 				}
441 				if (wi != WEOF)
442 					__ungetwc(wi, fp);
443 				*mbp = 0;
444 				nassigned++;
445 			}
446 			nread += n;
447 			nconversions++;
448 			break;
449 
450 		case CT_STRING:
451 			/* like CCL, but zero-length string OK, & no NOSKIP */
452 			if (width == 0)
453 				width = (size_t)~0;
454 			if (flags & SUPPRESS) {
455 				while ((wi = __fgetwc(fp)) != WEOF &&
456 				    width-- != 0 &&
457 				    !iswspace(wi))
458 					nread++;
459 				if (wi != WEOF)
460 					__ungetwc(wi, fp);
461 			} else if (flags & LONG) {
462 				p0 = p = va_arg(ap, wchar_t *);
463 				while ((wi = __fgetwc(fp)) != WEOF &&
464 				    width-- != 0 &&
465 				    !iswspace(wi)) {
466 					*p++ = (wchar_t)wi;
467 					nread++;
468 				}
469 				if (wi != WEOF)
470 					__ungetwc(wi, fp);
471 				*p = '\0';
472 				nassigned++;
473 			} else {
474 				mbp = va_arg(ap, char *);
475 				memset(&mbs, 0, sizeof(mbs));
476 				while ((wi = __fgetwc(fp)) != WEOF &&
477 				    width-- != 0 &&
478 				    !iswspace(wi)) {
479 					nconv = wcrtomb(mbp, wi, &mbs);
480 					if (nconv == (size_t)-1)
481 						goto input_failure;
482 					mbp += nconv;
483 					nread++;
484 				}
485 				if (wi != WEOF)
486 					__ungetwc(wi, fp);
487 				*mbp = 0;
488 				nassigned++;
489 			}
490 			nconversions++;
491 			continue;
492 
493 		case CT_INT:
494 			/* scan an integer as if by the conversion function */
495 #ifdef hardway
496 			if (width == 0 || width > sizeof(buf) - 1)
497 				width = sizeof(buf) - 1;
498 #else
499 			/* size_t is unsigned, hence this optimisation */
500 			if (--width > sizeof(buf) - 2)
501 				width = sizeof(buf) - 2;
502 			width++;
503 #endif
504 			flags |= SIGNOK | NDIGITS | NZDIGITS;
505 			for (p = buf; width; width--) {
506 				c = __fgetwc(fp);
507 				/*
508 				 * Switch on the character; `goto ok'
509 				 * if we accept it as a part of number.
510 				 */
511 				switch (c) {
512 
513 				/*
514 				 * The digit 0 is always legal, but is
515 				 * special.  For %i conversions, if no
516 				 * digits (zero or nonzero) have been
517 				 * scanned (only signs), we will have
518 				 * base==0.  In that case, we should set
519 				 * it to 8 and enable 0x prefixing.
520 				 * Also, if we have not scanned zero digits
521 				 * before this, do not turn off prefixing
522 				 * (someone else will turn it off if we
523 				 * have scanned any nonzero digits).
524 				 */
525 				case '0':
526 					if (base == 0) {
527 						base = 8;
528 						flags |= PFXOK;
529 					}
530 					if (flags & NZDIGITS)
531 					    flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
532 					else
533 					    flags &= ~(SIGNOK|PFXOK|NDIGITS);
534 					goto ok;
535 
536 				/* 1 through 7 always legal */
537 				case '1': case '2': case '3':
538 				case '4': case '5': case '6': case '7':
539 					base = basefix[base];
540 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
541 					goto ok;
542 
543 				/* digits 8 and 9 ok iff decimal or hex */
544 				case '8': case '9':
545 					base = basefix[base];
546 					if (base <= 8)
547 						break;	/* not legal here */
548 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
549 					goto ok;
550 
551 				/* letters ok iff hex */
552 				case 'A': case 'B': case 'C':
553 				case 'D': case 'E': case 'F':
554 				case 'a': case 'b': case 'c':
555 				case 'd': case 'e': case 'f':
556 					/* no need to fix base here */
557 					if (base <= 10)
558 						break;	/* not legal here */
559 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
560 					goto ok;
561 
562 				/* sign ok only as first character */
563 				case '+': case '-':
564 					if (flags & SIGNOK) {
565 						flags &= ~SIGNOK;
566 						goto ok;
567 					}
568 					break;
569 
570 				/* x ok iff flag still set & 2nd char */
571 				case 'x': case 'X':
572 					if (flags & PFXOK && p == buf + 1) {
573 						base = 16;	/* if %i */
574 						flags &= ~PFXOK;
575 						goto ok;
576 					}
577 					break;
578 				}
579 
580 				/*
581 				 * If we got here, c is not a legal character
582 				 * for a number.  Stop accumulating digits.
583 				 */
584 				if (c != WEOF)
585 					__ungetwc(c, fp);
586 				break;
587 		ok:
588 				/*
589 				 * c is legal: store it and look at the next.
590 				 */
591 				*p++ = (wchar_t)c;
592 			}
593 			/*
594 			 * If we had only a sign, it is no good; push
595 			 * back the sign.  If the number ends in `x',
596 			 * it was [sign] '0' 'x', so push back the x
597 			 * and treat it as [sign] '0'.
598 			 */
599 			if (flags & NDIGITS) {
600 				if (p > buf)
601 					__ungetwc(*--p, fp);
602 				goto match_failure;
603 			}
604 			c = p[-1];
605 			if (c == 'x' || c == 'X') {
606 				--p;
607 				__ungetwc(c, fp);
608 			}
609 			if ((flags & SUPPRESS) == 0) {
610 				uintmax_t res;
611 
612 				*p = 0;
613 				if ((flags & UNSIGNED) == 0)
614 				    res = wcstoimax(buf, NULL, base);
615 				else
616 				    res = wcstoumax(buf, NULL, base);
617 				if (flags & POINTER)
618 					*va_arg(ap, void **) =
619 							(void *)(uintptr_t)res;
620 				else if (flags & SHORTSHORT)
621 					*va_arg(ap, char *) = res;
622 				else if (flags & SHORT)
623 					*va_arg(ap, short *) = res;
624 				else if (flags & LONG)
625 					*va_arg(ap, long *) = res;
626 				else if (flags & LONGLONG)
627 					*va_arg(ap, long long *) = res;
628 				else if (flags & INTMAXT)
629 					*va_arg(ap, intmax_t *) = res;
630 				else if (flags & PTRDIFFT)
631 					*va_arg(ap, ptrdiff_t *) = res;
632 				else if (flags & SIZET)
633 					*va_arg(ap, size_t *) = res;
634 				else
635 					*va_arg(ap, int *) = res;
636 				nassigned++;
637 			}
638 			nread += p - buf;
639 			nconversions++;
640 			break;
641 
642 #ifdef FLOATING_POINT
643 		case CT_FLOAT:
644 			/* scan a floating point number as if by strtod */
645 #ifdef hardway
646 			if (width == 0 || width > sizeof(buf) - 1)
647 				width = sizeof(buf) - 1;
648 #else
649 			/* size_t is unsigned, hence this optimisation */
650 			if (--width > sizeof(buf) - 2)
651 				width = sizeof(buf) - 2;
652 			width++;
653 #endif
654 			flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
655 			for (p = buf; width; width--) {
656 				c = __fgetwc(fp);
657 				/*
658 				 * This code mimicks the integer conversion
659 				 * code, but is much simpler.
660 				 */
661 				switch (c) {
662 
663 				case '0': case '1': case '2': case '3':
664 				case '4': case '5': case '6': case '7':
665 				case '8': case '9':
666 					flags &= ~(SIGNOK | NDIGITS);
667 					goto fok;
668 
669 				case '+': case '-':
670 					if (flags & SIGNOK) {
671 						flags &= ~SIGNOK;
672 						goto fok;
673 					}
674 					break;
675 				case 'e': case 'E':
676 					/* no exponent without some digits */
677 					if ((flags&(NDIGITS|EXPOK)) == EXPOK) {
678 						flags =
679 						    (flags & ~(EXPOK|DPTOK)) |
680 						    SIGNOK | NDIGITS;
681 						goto fok;
682 					}
683 					break;
684 				default:
685 					if (c == (wchar_t)decimal_point &&
686 					    (flags & DPTOK)) {
687 						flags &= ~(SIGNOK | DPTOK);
688 						goto fok;
689 					}
690 					break;
691 				}
692 				if (c != WEOF)
693 					__ungetwc(c, fp);
694 				break;
695 		fok:
696 				*p++ = c;
697 			}
698 			/*
699 			 * If no digits, might be missing exponent digits
700 			 * (just give back the exponent) or might be missing
701 			 * regular digits, but had sign and/or decimal point.
702 			 */
703 			if (flags & NDIGITS) {
704 				if (flags & EXPOK) {
705 					/* no digits at all */
706 					while (p > buf)
707 						__ungetwc(*--p, fp);
708 					goto match_failure;
709 				}
710 				/* just a bad exponent (e and maybe sign) */
711 				c = *--p;
712 				if (c != 'e' && c != 'E') {
713 					__ungetwc(c, fp);/* sign */
714 					c = *--p;
715 				}
716 				__ungetwc(c, fp);
717 			}
718 			if ((flags & SUPPRESS) == 0) {
719 				double res;
720 
721 				*p = 0;
722 				/* XXX this loses precision for long doubles. */
723 				res = wcstod(buf, NULL);
724 				if (flags & LONGDBL)
725 					*va_arg(ap, long double *) = res;
726 				else if (flags & LONG)
727 					*va_arg(ap, double *) = res;
728 				else
729 					*va_arg(ap, float *) = res;
730 				nassigned++;
731 			}
732 			nread += p - buf;
733 			nconversions++;
734 			break;
735 #endif /* FLOATING_POINT */
736 		}
737 	}
738 input_failure:
739 	return (nconversions != 0 ? nassigned : EOF);
740 match_failure:
741 	return (nassigned);
742 }
743