xref: /freebsd/lib/libc/stdio/vfscanf.c (revision 2b743a9e9ddc6736208dc8ca1ce06ce64ad20a19)
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  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)vfscanf.c	8.1 (Berkeley) 6/4/93";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include "namespace.h"
40 #include <ctype.h>
41 #include <inttypes.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <stddef.h>
45 #include <stdarg.h>
46 #include <string.h>
47 #include <wchar.h>
48 #include <wctype.h>
49 #include "un-namespace.h"
50 
51 #include "collate.h"
52 #include "libc_private.h"
53 #include "local.h"
54 
55 #ifndef NO_FLOATING_POINT
56 #include <locale.h>
57 #endif
58 
59 #define	BUF		513	/* Maximum length of numeric string. */
60 
61 /*
62  * Flags used during conversion.
63  */
64 #define	LONG		0x01	/* l: long or double */
65 #define	LONGDBL		0x02	/* L: long double */
66 #define	SHORT		0x04	/* h: short */
67 #define	SUPPRESS	0x08	/* *: suppress assignment */
68 #define	POINTER		0x10	/* p: void * (as hex) */
69 #define	NOSKIP		0x20	/* [ or c: do not skip blanks */
70 #define	LONGLONG	0x400	/* ll: long long (+ deprecated q: quad) */
71 #define	INTMAXT		0x800	/* j: intmax_t */
72 #define	PTRDIFFT	0x1000	/* t: ptrdiff_t */
73 #define	SIZET		0x2000	/* z: size_t */
74 #define	SHORTSHORT	0x4000	/* hh: char */
75 #define	UNSIGNED	0x8000	/* %[oupxX] conversions */
76 
77 /*
78  * The following are used in integral conversions only:
79  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS
80  */
81 #define	SIGNOK		0x40	/* +/- is (still) legal */
82 #define	NDIGITS		0x80	/* no digits detected */
83 #define	PFXOK		0x100	/* 0x prefix is (still) legal */
84 #define	NZDIGITS	0x200	/* no zero digits detected */
85 #define	HAVESIGN	0x10000	/* sign detected */
86 
87 /*
88  * Conversion types.
89  */
90 #define	CT_CHAR		0	/* %c conversion */
91 #define	CT_CCL		1	/* %[...] conversion */
92 #define	CT_STRING	2	/* %s conversion */
93 #define	CT_INT		3	/* %[dioupxX] conversion */
94 #define	CT_FLOAT	4	/* %[efgEFG] conversion */
95 
96 static const u_char *__sccl(char *, const u_char *);
97 #ifndef NO_FLOATING_POINT
98 static int parsefloat(FILE *, char *, char *);
99 #endif
100 
101 int __scanfdebug = 0;
102 
103 __weak_reference(__vfscanf, vfscanf);
104 
105 /*
106  * __vfscanf - MT-safe version
107  */
108 int
109 __vfscanf(FILE *fp, char const *fmt0, va_list ap)
110 {
111 	int ret;
112 
113 	FLOCKFILE(fp);
114 	ret = __svfscanf(fp, fmt0, ap);
115 	FUNLOCKFILE(fp);
116 	return (ret);
117 }
118 
119 /*
120  * __svfscanf - non-MT-safe version of __vfscanf
121  */
122 int
123 __svfscanf(FILE *fp, const char *fmt0, va_list ap)
124 {
125 	const u_char *fmt = (const u_char *)fmt0;
126 	int c;			/* character from format, or conversion */
127 	size_t width;		/* field width, or 0 */
128 	char *p;		/* points into all kinds of strings */
129 	int n;			/* handy integer */
130 	int flags;		/* flags as defined above */
131 	char *p0;		/* saves original value of p when necessary */
132 	int nassigned;		/* number of fields assigned */
133 	int nconversions;	/* number of conversions */
134 	int nread;		/* number of characters consumed from fp */
135 	int base;		/* base argument to conversion function */
136 	char ccltab[256];	/* character class table for %[...] */
137 	char buf[BUF];		/* buffer for numeric and mb conversions */
138 	wchar_t *wcp;		/* handy wide character pointer */
139 	size_t nconv;		/* length of multibyte sequence converted */
140 	static const mbstate_t initial;
141 	mbstate_t mbs;
142 
143 	/* `basefix' is used to avoid `if' tests in the integer scanner */
144 	static short basefix[17] =
145 		{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
146 
147 	ORIENT(fp, -1);
148 
149 	nassigned = 0;
150 	nconversions = 0;
151 	nread = 0;
152 	for (;;) {
153 		c = *fmt++;
154 		if (c == 0)
155 			return (nassigned);
156 		if (isspace(c)) {
157 			while ((fp->_r > 0 || __srefill(fp) == 0) && isspace(*fp->_p))
158 				nread++, fp->_r--, fp->_p++;
159 			continue;
160 		}
161 		if (c != '%')
162 			goto literal;
163 		width = 0;
164 		flags = 0;
165 		/*
166 		 * switch on the format.  continue if done;
167 		 * break once format type is derived.
168 		 */
169 again:		c = *fmt++;
170 		switch (c) {
171 		case '%':
172 literal:
173 			if (fp->_r <= 0 && __srefill(fp))
174 				goto input_failure;
175 			if (*fp->_p != c)
176 				goto match_failure;
177 			fp->_r--, fp->_p++;
178 			nread++;
179 			continue;
180 
181 		case '*':
182 			flags |= SUPPRESS;
183 			goto again;
184 		case 'j':
185 			flags |= INTMAXT;
186 			goto again;
187 		case 'l':
188 			if (flags & LONG) {
189 				flags &= ~LONG;
190 				flags |= LONGLONG;
191 			} else
192 				flags |= LONG;
193 			goto again;
194 		case 'q':
195 			flags |= LONGLONG;	/* not quite */
196 			goto again;
197 		case 't':
198 			flags |= PTRDIFFT;
199 			goto again;
200 		case 'z':
201 			flags |= SIZET;
202 			goto again;
203 		case 'L':
204 			flags |= LONGDBL;
205 			goto again;
206 		case 'h':
207 			if (flags & SHORT) {
208 				flags &= ~SHORT;
209 				flags |= SHORTSHORT;
210 			} else
211 				flags |= SHORT;
212 			goto again;
213 
214 		case '0': case '1': case '2': case '3': case '4':
215 		case '5': case '6': case '7': case '8': case '9':
216 			width = width * 10 + c - '0';
217 			goto again;
218 
219 		/*
220 		 * Conversions.
221 		 */
222 		case 'd':
223 			c = CT_INT;
224 			base = 10;
225 			break;
226 
227 		case 'i':
228 			c = CT_INT;
229 			base = 0;
230 			break;
231 
232 		case 'o':
233 			c = CT_INT;
234 			flags |= UNSIGNED;
235 			base = 8;
236 			break;
237 
238 		case 'u':
239 			c = CT_INT;
240 			flags |= UNSIGNED;
241 			base = 10;
242 			break;
243 
244 		case 'X':
245 		case 'x':
246 			flags |= PFXOK;	/* enable 0x prefixing */
247 			c = CT_INT;
248 			flags |= UNSIGNED;
249 			base = 16;
250 			break;
251 
252 #ifndef NO_FLOATING_POINT
253 		case 'A': case 'E': case 'F': case 'G':
254 		case 'a': case 'e': case 'f': case 'g':
255 			c = CT_FLOAT;
256 			break;
257 #endif
258 
259 		case 'S':
260 			flags |= LONG;
261 			/* FALLTHROUGH */
262 		case 's':
263 			c = CT_STRING;
264 			break;
265 
266 		case '[':
267 			fmt = __sccl(ccltab, fmt);
268 			flags |= NOSKIP;
269 			c = CT_CCL;
270 			break;
271 
272 		case 'C':
273 			flags |= LONG;
274 			/* FALLTHROUGH */
275 		case 'c':
276 			flags |= NOSKIP;
277 			c = CT_CHAR;
278 			break;
279 
280 		case 'p':	/* pointer format is like hex */
281 			flags |= POINTER | PFXOK;
282 			c = CT_INT;		/* assumes sizeof(uintmax_t) */
283 			flags |= UNSIGNED;	/*      >= sizeof(uintptr_t) */
284 			base = 16;
285 			break;
286 
287 		case 'n':
288 			nconversions++;
289 			if (flags & SUPPRESS)	/* ??? */
290 				continue;
291 			if (flags & SHORTSHORT)
292 				*va_arg(ap, char *) = nread;
293 			else if (flags & SHORT)
294 				*va_arg(ap, short *) = nread;
295 			else if (flags & LONG)
296 				*va_arg(ap, long *) = nread;
297 			else if (flags & LONGLONG)
298 				*va_arg(ap, long long *) = nread;
299 			else if (flags & INTMAXT)
300 				*va_arg(ap, intmax_t *) = nread;
301 			else if (flags & SIZET)
302 				*va_arg(ap, size_t *) = nread;
303 			else if (flags & PTRDIFFT)
304 				*va_arg(ap, ptrdiff_t *) = nread;
305 			else
306 				*va_arg(ap, int *) = nread;
307 			continue;
308 
309 		default:
310 			goto match_failure;
311 
312 		/*
313 		 * Disgusting backwards compatibility hack.	XXX
314 		 */
315 		case '\0':	/* compat */
316 			return (EOF);
317 		}
318 
319 		/*
320 		 * We have a conversion that requires input.
321 		 */
322 		if (fp->_r <= 0 && __srefill(fp))
323 			goto input_failure;
324 
325 		/*
326 		 * Consume leading white space, except for formats
327 		 * that suppress this.
328 		 */
329 		if ((flags & NOSKIP) == 0) {
330 			while (isspace(*fp->_p)) {
331 				nread++;
332 				if (--fp->_r > 0)
333 					fp->_p++;
334 				else if (__srefill(fp))
335 					goto input_failure;
336 			}
337 			/*
338 			 * Note that there is at least one character in
339 			 * the buffer, so conversions that do not set NOSKIP
340 			 * ca no longer result in an input failure.
341 			 */
342 		}
343 
344 		/*
345 		 * Do the conversion.
346 		 */
347 		switch (c) {
348 
349 		case CT_CHAR:
350 			/* scan arbitrary characters (sets NOSKIP) */
351 			if (width == 0)
352 				width = 1;
353 			if (flags & LONG) {
354 				if ((flags & SUPPRESS) == 0)
355 					wcp = va_arg(ap, wchar_t *);
356 				else
357 					wcp = NULL;
358 				n = 0;
359 				while (width != 0) {
360 					if (n == MB_CUR_MAX) {
361 						fp->_flags |= __SERR;
362 						goto input_failure;
363 					}
364 					buf[n++] = *fp->_p;
365 					fp->_p++;
366 					fp->_r--;
367 					mbs = initial;
368 					nconv = mbrtowc(wcp, buf, n, &mbs);
369 					if (nconv == (size_t)-1) {
370 						fp->_flags |= __SERR;
371 						goto input_failure;
372 					}
373 					if (nconv == 0 && !(flags & SUPPRESS))
374 						*wcp = L'\0';
375 					if (nconv != (size_t)-2) {
376 						nread += n;
377 						width--;
378 						if (!(flags & SUPPRESS))
379 							wcp++;
380 						n = 0;
381 					}
382 					if (fp->_r <= 0 && __srefill(fp)) {
383 						if (n != 0) {
384 							fp->_flags |= __SERR;
385 							goto input_failure;
386 						}
387 						break;
388 					}
389 				}
390 				if (!(flags & SUPPRESS))
391 					nassigned++;
392 			} else if (flags & SUPPRESS) {
393 				size_t sum = 0;
394 				for (;;) {
395 					if ((n = fp->_r) < width) {
396 						sum += n;
397 						width -= n;
398 						fp->_p += n;
399 						if (__srefill(fp)) {
400 							if (sum == 0)
401 							    goto input_failure;
402 							break;
403 						}
404 					} else {
405 						sum += width;
406 						fp->_r -= width;
407 						fp->_p += width;
408 						break;
409 					}
410 				}
411 				nread += sum;
412 			} else {
413 				size_t r = __fread((void *)va_arg(ap, char *), 1,
414 				    width, fp);
415 
416 				if (r == 0)
417 					goto input_failure;
418 				nread += r;
419 				nassigned++;
420 			}
421 			nconversions++;
422 			break;
423 
424 		case CT_CCL:
425 			/* scan a (nonempty) character class (sets NOSKIP) */
426 			if (width == 0)
427 				width = (size_t)~0;	/* `infinity' */
428 			/* take only those things in the class */
429 			if (flags & LONG) {
430 				wchar_t twc;
431 				int nchars;
432 
433 				if ((flags & SUPPRESS) == 0)
434 					wcp = va_arg(ap, wchar_t *);
435 				else
436 					wcp = &twc;
437 				n = 0;
438 				nchars = 0;
439 				while (width != 0) {
440 					if (n == MB_CUR_MAX) {
441 						fp->_flags |= __SERR;
442 						goto input_failure;
443 					}
444 					buf[n++] = *fp->_p;
445 					fp->_p++;
446 					fp->_r--;
447 					mbs = initial;
448 					nconv = mbrtowc(wcp, buf, n, &mbs);
449 					if (nconv == (size_t)-1) {
450 						fp->_flags |= __SERR;
451 						goto input_failure;
452 					}
453 					if (nconv == 0)
454 						*wcp = L'\0';
455 					if (nconv != (size_t)-2) {
456 						if (wctob(*wcp) != EOF &&
457 						    !ccltab[wctob(*wcp)]) {
458 							while (n != 0) {
459 								n--;
460 								__ungetc(buf[n],
461 								    fp);
462 							}
463 							break;
464 						}
465 						nread += n;
466 						width--;
467 						if (!(flags & SUPPRESS))
468 							wcp++;
469 						nchars++;
470 						n = 0;
471 					}
472 					if (fp->_r <= 0 && __srefill(fp)) {
473 						if (n != 0) {
474 							fp->_flags |= __SERR;
475 							goto input_failure;
476 						}
477 						break;
478 					}
479 				}
480 				if (n != 0) {
481 					fp->_flags |= __SERR;
482 					goto input_failure;
483 				}
484 				n = nchars;
485 				if (n == 0)
486 					goto match_failure;
487 				if (!(flags & SUPPRESS)) {
488 					*wcp = L'\0';
489 					nassigned++;
490 				}
491 			} else if (flags & SUPPRESS) {
492 				n = 0;
493 				while (ccltab[*fp->_p]) {
494 					n++, fp->_r--, fp->_p++;
495 					if (--width == 0)
496 						break;
497 					if (fp->_r <= 0 && __srefill(fp)) {
498 						if (n == 0)
499 							goto input_failure;
500 						break;
501 					}
502 				}
503 				if (n == 0)
504 					goto match_failure;
505 			} else {
506 				p0 = p = va_arg(ap, char *);
507 				while (ccltab[*fp->_p]) {
508 					fp->_r--;
509 					*p++ = *fp->_p++;
510 					if (--width == 0)
511 						break;
512 					if (fp->_r <= 0 && __srefill(fp)) {
513 						if (p == p0)
514 							goto input_failure;
515 						break;
516 					}
517 				}
518 				n = p - p0;
519 				if (n == 0)
520 					goto match_failure;
521 				*p = 0;
522 				nassigned++;
523 			}
524 			nread += n;
525 			nconversions++;
526 			break;
527 
528 		case CT_STRING:
529 			/* like CCL, but zero-length string OK, & no NOSKIP */
530 			if (width == 0)
531 				width = (size_t)~0;
532 			if (flags & LONG) {
533 				wchar_t twc;
534 
535 				if ((flags & SUPPRESS) == 0)
536 					wcp = va_arg(ap, wchar_t *);
537 				else
538 					wcp = &twc;
539 				n = 0;
540 				while (!isspace(*fp->_p) && width != 0) {
541 					if (n == MB_CUR_MAX) {
542 						fp->_flags |= __SERR;
543 						goto input_failure;
544 					}
545 					buf[n++] = *fp->_p;
546 					fp->_p++;
547 					fp->_r--;
548 					mbs = initial;
549 					nconv = mbrtowc(wcp, buf, n, &mbs);
550 					if (nconv == (size_t)-1) {
551 						fp->_flags |= __SERR;
552 						goto input_failure;
553 					}
554 					if (nconv == 0)
555 						*wcp = L'\0';
556 					if (nconv != (size_t)-2) {
557 						if (iswspace(*wcp)) {
558 							while (n != 0) {
559 								n--;
560 								__ungetc(buf[n],
561 								    fp);
562 							}
563 							break;
564 						}
565 						nread += n;
566 						width--;
567 						if (!(flags & SUPPRESS))
568 							wcp++;
569 						n = 0;
570 					}
571 					if (fp->_r <= 0 && __srefill(fp)) {
572 						if (n != 0) {
573 							fp->_flags |= __SERR;
574 							goto input_failure;
575 						}
576 						break;
577 					}
578 				}
579 				if (!(flags & SUPPRESS)) {
580 					*wcp = L'\0';
581 					nassigned++;
582 				}
583 			} else if (flags & SUPPRESS) {
584 				n = 0;
585 				while (!isspace(*fp->_p)) {
586 					n++, fp->_r--, fp->_p++;
587 					if (--width == 0)
588 						break;
589 					if (fp->_r <= 0 && __srefill(fp))
590 						break;
591 				}
592 				nread += n;
593 			} else {
594 				p0 = p = va_arg(ap, char *);
595 				while (!isspace(*fp->_p)) {
596 					fp->_r--;
597 					*p++ = *fp->_p++;
598 					if (--width == 0)
599 						break;
600 					if (fp->_r <= 0 && __srefill(fp))
601 						break;
602 				}
603 				*p = 0;
604 				nread += p - p0;
605 				nassigned++;
606 			}
607 			nconversions++;
608 			continue;
609 
610 		case CT_INT:
611 			/* scan an integer as if by the conversion function */
612 #ifdef hardway
613 			if (width == 0 || width > sizeof(buf) - 1)
614 				width = sizeof(buf) - 1;
615 #else
616 			/* size_t is unsigned, hence this optimisation */
617 			if (--width > sizeof(buf) - 2)
618 				width = sizeof(buf) - 2;
619 			width++;
620 #endif
621 			flags |= SIGNOK | NDIGITS | NZDIGITS;
622 			for (p = buf; width; width--) {
623 				c = *fp->_p;
624 				/*
625 				 * Switch on the character; `goto ok'
626 				 * if we accept it as a part of number.
627 				 */
628 				switch (c) {
629 
630 				/*
631 				 * The digit 0 is always legal, but is
632 				 * special.  For %i conversions, if no
633 				 * digits (zero or nonzero) have been
634 				 * scanned (only signs), we will have
635 				 * base==0.  In that case, we should set
636 				 * it to 8 and enable 0x prefixing.
637 				 * Also, if we have not scanned zero digits
638 				 * before this, do not turn off prefixing
639 				 * (someone else will turn it off if we
640 				 * have scanned any nonzero digits).
641 				 */
642 				case '0':
643 					if (base == 0) {
644 						base = 8;
645 						flags |= PFXOK;
646 					}
647 					if (flags & NZDIGITS)
648 					    flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
649 					else
650 					    flags &= ~(SIGNOK|PFXOK|NDIGITS);
651 					goto ok;
652 
653 				/* 1 through 7 always legal */
654 				case '1': case '2': case '3':
655 				case '4': case '5': case '6': case '7':
656 					base = basefix[base];
657 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
658 					goto ok;
659 
660 				/* digits 8 and 9 ok iff decimal or hex */
661 				case '8': case '9':
662 					base = basefix[base];
663 					if (base <= 8)
664 						break;	/* not legal here */
665 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
666 					goto ok;
667 
668 				/* letters ok iff hex */
669 				case 'A': case 'B': case 'C':
670 				case 'D': case 'E': case 'F':
671 				case 'a': case 'b': case 'c':
672 				case 'd': case 'e': case 'f':
673 					/* no need to fix base here */
674 					if (base <= 10)
675 						break;	/* not legal here */
676 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
677 					goto ok;
678 
679 				/* sign ok only as first character */
680 				case '+': case '-':
681 					if (flags & SIGNOK) {
682 						flags &= ~SIGNOK;
683 						flags |= HAVESIGN;
684 						goto ok;
685 					}
686 					break;
687 
688 				/*
689 				 * x ok iff flag still set & 2nd char (or
690 				 * 3rd char if we have a sign).
691 				 */
692 				case 'x': case 'X':
693 					if (flags & PFXOK && p ==
694 					    buf + 1 + !!(flags & HAVESIGN)) {
695 						base = 16;	/* if %i */
696 						flags &= ~PFXOK;
697 						goto ok;
698 					}
699 					break;
700 				}
701 
702 				/*
703 				 * If we got here, c is not a legal character
704 				 * for a number.  Stop accumulating digits.
705 				 */
706 				break;
707 		ok:
708 				/*
709 				 * c is legal: store it and look at the next.
710 				 */
711 				*p++ = c;
712 				if (--fp->_r > 0)
713 					fp->_p++;
714 				else if (__srefill(fp))
715 					break;		/* EOF */
716 			}
717 			/*
718 			 * If we had only a sign, it is no good; push
719 			 * back the sign.  If the number ends in `x',
720 			 * it was [sign] '0' 'x', so push back the x
721 			 * and treat it as [sign] '0'.
722 			 */
723 			if (flags & NDIGITS) {
724 				if (p > buf)
725 					(void) __ungetc(*(u_char *)--p, fp);
726 				goto match_failure;
727 			}
728 			c = ((u_char *)p)[-1];
729 			if (c == 'x' || c == 'X') {
730 				--p;
731 				(void) __ungetc(c, fp);
732 			}
733 			if ((flags & SUPPRESS) == 0) {
734 				uintmax_t res;
735 
736 				*p = 0;
737 				if ((flags & UNSIGNED) == 0)
738 				    res = strtoimax(buf, (char **)NULL, base);
739 				else
740 				    res = strtoumax(buf, (char **)NULL, base);
741 				if (flags & POINTER)
742 					*va_arg(ap, void **) =
743 							(void *)(uintptr_t)res;
744 				else if (flags & SHORTSHORT)
745 					*va_arg(ap, char *) = res;
746 				else if (flags & SHORT)
747 					*va_arg(ap, short *) = res;
748 				else if (flags & LONG)
749 					*va_arg(ap, long *) = res;
750 				else if (flags & LONGLONG)
751 					*va_arg(ap, long long *) = res;
752 				else if (flags & INTMAXT)
753 					*va_arg(ap, intmax_t *) = res;
754 				else if (flags & PTRDIFFT)
755 					*va_arg(ap, ptrdiff_t *) = res;
756 				else if (flags & SIZET)
757 					*va_arg(ap, size_t *) = res;
758 				else
759 					*va_arg(ap, int *) = res;
760 				nassigned++;
761 			}
762 			nread += p - buf;
763 			nconversions++;
764 			break;
765 
766 #ifndef NO_FLOATING_POINT
767 		case CT_FLOAT:
768 			/* scan a floating point number as if by strtod */
769 			if (width == 0 || width > sizeof(buf) - 1)
770 				width = sizeof(buf) - 1;
771 			if ((width = parsefloat(fp, buf, buf + width)) == 0)
772 				goto match_failure;
773 			if ((flags & SUPPRESS) == 0) {
774 				if (flags & LONGDBL) {
775 					long double res = strtold(buf, &p);
776 					*va_arg(ap, long double *) = res;
777 				} else if (flags & LONG) {
778 					double res = strtod(buf, &p);
779 					*va_arg(ap, double *) = res;
780 				} else {
781 					float res = strtof(buf, &p);
782 					*va_arg(ap, float *) = res;
783 				}
784 				if (__scanfdebug && p - buf != width)
785 					abort();
786 				nassigned++;
787 			}
788 			nread += width;
789 			nconversions++;
790 			break;
791 #endif /* !NO_FLOATING_POINT */
792 		}
793 	}
794 input_failure:
795 	return (nconversions != 0 ? nassigned : EOF);
796 match_failure:
797 	return (nassigned);
798 }
799 
800 /*
801  * Fill in the given table from the scanset at the given format
802  * (just after `[').  Return a pointer to the character past the
803  * closing `]'.  The table has a 1 wherever characters should be
804  * considered part of the scanset.
805  */
806 static const u_char *
807 __sccl(tab, fmt)
808 	char *tab;
809 	const u_char *fmt;
810 {
811 	int c, n, v, i;
812 
813 	/* first `clear' the whole table */
814 	c = *fmt++;		/* first char hat => negated scanset */
815 	if (c == '^') {
816 		v = 1;		/* default => accept */
817 		c = *fmt++;	/* get new first char */
818 	} else
819 		v = 0;		/* default => reject */
820 
821 	/* XXX: Will not work if sizeof(tab*) > sizeof(char) */
822 	(void) memset(tab, v, 256);
823 
824 	if (c == 0)
825 		return (fmt - 1);/* format ended before closing ] */
826 
827 	/*
828 	 * Now set the entries corresponding to the actual scanset
829 	 * to the opposite of the above.
830 	 *
831 	 * The first character may be ']' (or '-') without being special;
832 	 * the last character may be '-'.
833 	 */
834 	v = 1 - v;
835 	for (;;) {
836 		tab[c] = v;		/* take character c */
837 doswitch:
838 		n = *fmt++;		/* and examine the next */
839 		switch (n) {
840 
841 		case 0:			/* format ended too soon */
842 			return (fmt - 1);
843 
844 		case '-':
845 			/*
846 			 * A scanset of the form
847 			 *	[01+-]
848 			 * is defined as `the digit 0, the digit 1,
849 			 * the character +, the character -', but
850 			 * the effect of a scanset such as
851 			 *	[a-zA-Z0-9]
852 			 * is implementation defined.  The V7 Unix
853 			 * scanf treats `a-z' as `the letters a through
854 			 * z', but treats `a-a' as `the letter a, the
855 			 * character -, and the letter a'.
856 			 *
857 			 * For compatibility, the `-' is not considerd
858 			 * to define a range if the character following
859 			 * it is either a close bracket (required by ANSI)
860 			 * or is not numerically greater than the character
861 			 * we just stored in the table (c).
862 			 */
863 			n = *fmt;
864 			if (n == ']'
865 			    || (__collate_load_error ? n < c :
866 				__collate_range_cmp (n, c) < 0
867 			       )
868 			   ) {
869 				c = '-';
870 				break;	/* resume the for(;;) */
871 			}
872 			fmt++;
873 			/* fill in the range */
874 			if (__collate_load_error) {
875 				do {
876 					tab[++c] = v;
877 				} while (c < n);
878 			} else {
879 				for (i = 0; i < 256; i ++)
880 					if (   __collate_range_cmp (c, i) < 0
881 					    && __collate_range_cmp (i, n) <= 0
882 					   )
883 						tab[i] = v;
884 			}
885 #if 1	/* XXX another disgusting compatibility hack */
886 			c = n;
887 			/*
888 			 * Alas, the V7 Unix scanf also treats formats
889 			 * such as [a-c-e] as `the letters a through e'.
890 			 * This too is permitted by the standard....
891 			 */
892 			goto doswitch;
893 #else
894 			c = *fmt++;
895 			if (c == 0)
896 				return (fmt - 1);
897 			if (c == ']')
898 				return (fmt);
899 #endif
900 			break;
901 
902 		case ']':		/* end of scanset */
903 			return (fmt);
904 
905 		default:		/* just another character */
906 			c = n;
907 			break;
908 		}
909 	}
910 	/* NOTREACHED */
911 }
912 
913 #ifndef NO_FLOATING_POINT
914 static int
915 parsefloat(FILE *fp, char *buf, char *end)
916 {
917 	char *commit, *p;
918 	int infnanpos = 0;
919 	enum {
920 		S_START, S_GOTSIGN, S_INF, S_NAN, S_MAYBEHEX,
921 		S_DIGITS, S_FRAC, S_EXP, S_EXPDIGITS
922 	} state = S_START;
923 	unsigned char c;
924 	char decpt = *localeconv()->decimal_point;
925 	_Bool gotmantdig = 0, ishex = 0;
926 
927 	/*
928 	 * We set commit = p whenever the string we have read so far
929 	 * constitutes a valid representation of a floating point
930 	 * number by itself.  At some point, the parse will complete
931 	 * or fail, and we will ungetc() back to the last commit point.
932 	 * To ensure that the file offset gets updated properly, it is
933 	 * always necessary to read at least one character that doesn't
934 	 * match; thus, we can't short-circuit "infinity" or "nan(...)".
935 	 */
936 	commit = buf - 1;
937 	for (p = buf; p < end; ) {
938 		c = *fp->_p;
939 reswitch:
940 		switch (state) {
941 		case S_START:
942 			state = S_GOTSIGN;
943 			if (c == '-' || c == '+')
944 				break;
945 			else
946 				goto reswitch;
947 		case S_GOTSIGN:
948 			switch (c) {
949 			case '0':
950 				state = S_MAYBEHEX;
951 				commit = p;
952 				break;
953 			case 'I':
954 			case 'i':
955 				state = S_INF;
956 				break;
957 			case 'N':
958 			case 'n':
959 				state = S_NAN;
960 				break;
961 			default:
962 				state = S_DIGITS;
963 				goto reswitch;
964 			}
965 			break;
966 		case S_INF:
967 			if (infnanpos > 6 ||
968 			    (c != "nfinity"[infnanpos] &&
969 			     c != "NFINITY"[infnanpos]))
970 				goto parsedone;
971 			if (infnanpos == 1 || infnanpos == 6)
972 				commit = p;	/* inf or infinity */
973 			infnanpos++;
974 			break;
975 		case S_NAN:
976 			switch (infnanpos) {
977 			case -1:	/* XXX kludge to deal with nan(...) */
978 				goto parsedone;
979 			case 0:
980 				if (c != 'A' && c != 'a')
981 					goto parsedone;
982 				break;
983 			case 1:
984 				if (c != 'N' && c != 'n')
985 					goto parsedone;
986 				else
987 					commit = p;
988 				break;
989 			case 2:
990 				if (c != '(')
991 					goto parsedone;
992 				break;
993 			default:
994 				if (c == ')') {
995 					commit = p;
996 					infnanpos = -2;
997 				} else if (!isalnum(c) && c != '_')
998 					goto parsedone;
999 				break;
1000 			}
1001 			infnanpos++;
1002 			break;
1003 		case S_MAYBEHEX:
1004 			state = S_DIGITS;
1005 			if (c == 'X' || c == 'x') {
1006 				ishex = 1;
1007 				break;
1008 			} else {	/* we saw a '0', but no 'x' */
1009 				gotmantdig = 1;
1010 				goto reswitch;
1011 			}
1012 		case S_DIGITS:
1013 			if ((ishex && isxdigit(c)) || isdigit(c))
1014 				gotmantdig = 1;
1015 			else {
1016 				state = S_FRAC;
1017 				if (c != decpt)
1018 					goto reswitch;
1019 			}
1020 			if (gotmantdig)
1021 				commit = p;
1022 			break;
1023 		case S_FRAC:
1024 			if (((c == 'E' || c == 'e') && !ishex) ||
1025 			    ((c == 'P' || c == 'p') && ishex)) {
1026 				if (!gotmantdig)
1027 					goto parsedone;
1028 				else
1029 					state = S_EXP;
1030 			} else if ((ishex && isxdigit(c)) || isdigit(c)) {
1031 				commit = p;
1032 				gotmantdig = 1;
1033 			} else
1034 				goto parsedone;
1035 			break;
1036 		case S_EXP:
1037 			state = S_EXPDIGITS;
1038 			if (c == '-' || c == '+')
1039 				break;
1040 			else
1041 				goto reswitch;
1042 		case S_EXPDIGITS:
1043 			if (isdigit(c))
1044 				commit = p;
1045 			else
1046 				goto parsedone;
1047 			break;
1048 		default:
1049 			abort();
1050 		}
1051 		*p++ = c;
1052 		if (--fp->_r > 0)
1053 			fp->_p++;
1054 		else if (__srefill(fp))
1055 			break;	/* EOF */
1056 	}
1057 
1058 parsedone:
1059 	while (commit < --p)
1060 		__ungetc(*(u_char *)p, fp);
1061 	*++commit = '\0';
1062 	return (commit - buf);
1063 }
1064 #endif
1065