xref: /freebsd/lib/libc/stdio/vfscanf.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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 __weak_reference(__vfscanf, vfscanf);
102 
103 /*
104  * __vfscanf - MT-safe version
105  */
106 int
107 __vfscanf(FILE *fp, char const *fmt0, va_list ap)
108 {
109 	int ret;
110 
111 	FLOCKFILE(fp);
112 	ret = __svfscanf(fp, fmt0, ap);
113 	FUNLOCKFILE(fp);
114 	return (ret);
115 }
116 
117 /*
118  * __svfscanf - non-MT-safe version of __vfscanf
119  */
120 int
121 __svfscanf(FILE *fp, const char *fmt0, va_list ap)
122 {
123 	const u_char *fmt = (const u_char *)fmt0;
124 	int c;			/* character from format, or conversion */
125 	size_t width;		/* field width, or 0 */
126 	char *p;		/* points into all kinds of strings */
127 	int n;			/* handy integer */
128 	int flags;		/* flags as defined above */
129 	char *p0;		/* saves original value of p when necessary */
130 	int nassigned;		/* number of fields assigned */
131 	int nconversions;	/* number of conversions */
132 	int nread;		/* number of characters consumed from fp */
133 	int base;		/* base argument to conversion function */
134 	char ccltab[256];	/* character class table for %[...] */
135 	char buf[BUF];		/* buffer for numeric and mb conversions */
136 	wchar_t *wcp;		/* handy wide character pointer */
137 	size_t nconv;		/* length of multibyte sequence converted */
138 	static const mbstate_t initial;
139 	mbstate_t mbs;
140 
141 	/* `basefix' is used to avoid `if' tests in the integer scanner */
142 	static short basefix[17] =
143 		{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
144 
145 	ORIENT(fp, -1);
146 
147 	nassigned = 0;
148 	nconversions = 0;
149 	nread = 0;
150 	for (;;) {
151 		c = *fmt++;
152 		if (c == 0)
153 			return (nassigned);
154 		if (isspace(c)) {
155 			while ((fp->_r > 0 || __srefill(fp) == 0) && isspace(*fp->_p))
156 				nread++, fp->_r--, fp->_p++;
157 			continue;
158 		}
159 		if (c != '%')
160 			goto literal;
161 		width = 0;
162 		flags = 0;
163 		/*
164 		 * switch on the format.  continue if done;
165 		 * break once format type is derived.
166 		 */
167 again:		c = *fmt++;
168 		switch (c) {
169 		case '%':
170 literal:
171 			if (fp->_r <= 0 && __srefill(fp))
172 				goto input_failure;
173 			if (*fp->_p != c)
174 				goto match_failure;
175 			fp->_r--, fp->_p++;
176 			nread++;
177 			continue;
178 
179 		case '*':
180 			flags |= SUPPRESS;
181 			goto again;
182 		case 'j':
183 			flags |= INTMAXT;
184 			goto again;
185 		case 'l':
186 			if (flags & LONG) {
187 				flags &= ~LONG;
188 				flags |= LONGLONG;
189 			} else
190 				flags |= LONG;
191 			goto again;
192 		case 'q':
193 			flags |= LONGLONG;	/* not quite */
194 			goto again;
195 		case 't':
196 			flags |= PTRDIFFT;
197 			goto again;
198 		case 'z':
199 			flags |= SIZET;
200 			goto again;
201 		case 'L':
202 			flags |= LONGDBL;
203 			goto again;
204 		case 'h':
205 			if (flags & SHORT) {
206 				flags &= ~SHORT;
207 				flags |= SHORTSHORT;
208 			} else
209 				flags |= SHORT;
210 			goto again;
211 
212 		case '0': case '1': case '2': case '3': case '4':
213 		case '5': case '6': case '7': case '8': case '9':
214 			width = width * 10 + c - '0';
215 			goto again;
216 
217 		/*
218 		 * Conversions.
219 		 */
220 		case 'd':
221 			c = CT_INT;
222 			base = 10;
223 			break;
224 
225 		case 'i':
226 			c = CT_INT;
227 			base = 0;
228 			break;
229 
230 		case 'o':
231 			c = CT_INT;
232 			flags |= UNSIGNED;
233 			base = 8;
234 			break;
235 
236 		case 'u':
237 			c = CT_INT;
238 			flags |= UNSIGNED;
239 			base = 10;
240 			break;
241 
242 		case 'X':
243 		case 'x':
244 			flags |= PFXOK;	/* enable 0x prefixing */
245 			c = CT_INT;
246 			flags |= UNSIGNED;
247 			base = 16;
248 			break;
249 
250 #ifndef NO_FLOATING_POINT
251 		case 'A': case 'E': case 'F': case 'G':
252 		case 'a': case 'e': case 'f': case 'g':
253 			c = CT_FLOAT;
254 			break;
255 #endif
256 
257 		case 'S':
258 			flags |= LONG;
259 			/* FALLTHROUGH */
260 		case 's':
261 			c = CT_STRING;
262 			break;
263 
264 		case '[':
265 			fmt = __sccl(ccltab, fmt);
266 			flags |= NOSKIP;
267 			c = CT_CCL;
268 			break;
269 
270 		case 'C':
271 			flags |= LONG;
272 			/* FALLTHROUGH */
273 		case 'c':
274 			flags |= NOSKIP;
275 			c = CT_CHAR;
276 			break;
277 
278 		case 'p':	/* pointer format is like hex */
279 			flags |= POINTER | PFXOK;
280 			c = CT_INT;		/* assumes sizeof(uintmax_t) */
281 			flags |= UNSIGNED;	/*      >= sizeof(uintptr_t) */
282 			base = 16;
283 			break;
284 
285 		case 'n':
286 			nconversions++;
287 			if (flags & SUPPRESS)	/* ??? */
288 				continue;
289 			if (flags & SHORTSHORT)
290 				*va_arg(ap, char *) = nread;
291 			else if (flags & SHORT)
292 				*va_arg(ap, short *) = nread;
293 			else if (flags & LONG)
294 				*va_arg(ap, long *) = nread;
295 			else if (flags & LONGLONG)
296 				*va_arg(ap, long long *) = nread;
297 			else if (flags & INTMAXT)
298 				*va_arg(ap, intmax_t *) = nread;
299 			else if (flags & SIZET)
300 				*va_arg(ap, size_t *) = nread;
301 			else if (flags & PTRDIFFT)
302 				*va_arg(ap, ptrdiff_t *) = nread;
303 			else
304 				*va_arg(ap, int *) = nread;
305 			continue;
306 
307 		default:
308 			goto match_failure;
309 
310 		/*
311 		 * Disgusting backwards compatibility hack.	XXX
312 		 */
313 		case '\0':	/* compat */
314 			return (EOF);
315 		}
316 
317 		/*
318 		 * We have a conversion that requires input.
319 		 */
320 		if (fp->_r <= 0 && __srefill(fp))
321 			goto input_failure;
322 
323 		/*
324 		 * Consume leading white space, except for formats
325 		 * that suppress this.
326 		 */
327 		if ((flags & NOSKIP) == 0) {
328 			while (isspace(*fp->_p)) {
329 				nread++;
330 				if (--fp->_r > 0)
331 					fp->_p++;
332 				else if (__srefill(fp))
333 					goto input_failure;
334 			}
335 			/*
336 			 * Note that there is at least one character in
337 			 * the buffer, so conversions that do not set NOSKIP
338 			 * ca no longer result in an input failure.
339 			 */
340 		}
341 
342 		/*
343 		 * Do the conversion.
344 		 */
345 		switch (c) {
346 
347 		case CT_CHAR:
348 			/* scan arbitrary characters (sets NOSKIP) */
349 			if (width == 0)
350 				width = 1;
351 			if (flags & LONG) {
352 				if ((flags & SUPPRESS) == 0)
353 					wcp = va_arg(ap, wchar_t *);
354 				else
355 					wcp = NULL;
356 				n = 0;
357 				while (width != 0) {
358 					if (n == MB_CUR_MAX) {
359 						fp->_flags |= __SERR;
360 						goto input_failure;
361 					}
362 					buf[n++] = *fp->_p;
363 					fp->_p++;
364 					fp->_r--;
365 					mbs = initial;
366 					nconv = mbrtowc(wcp, buf, n, &mbs);
367 					if (nconv == (size_t)-1) {
368 						fp->_flags |= __SERR;
369 						goto input_failure;
370 					}
371 					if (nconv == 0 && !(flags & SUPPRESS))
372 						*wcp = L'\0';
373 					if (nconv != (size_t)-2) {
374 						nread += n;
375 						width--;
376 						if (!(flags & SUPPRESS))
377 							wcp++;
378 						n = 0;
379 					}
380 					if (fp->_r <= 0 && __srefill(fp)) {
381 						if (n != 0) {
382 							fp->_flags |= __SERR;
383 							goto input_failure;
384 						}
385 						break;
386 					}
387 				}
388 				if (!(flags & SUPPRESS))
389 					nassigned++;
390 			} else if (flags & SUPPRESS) {
391 				size_t sum = 0;
392 				for (;;) {
393 					if ((n = fp->_r) < width) {
394 						sum += n;
395 						width -= n;
396 						fp->_p += n;
397 						if (__srefill(fp)) {
398 							if (sum == 0)
399 							    goto input_failure;
400 							break;
401 						}
402 					} else {
403 						sum += width;
404 						fp->_r -= width;
405 						fp->_p += width;
406 						break;
407 					}
408 				}
409 				nread += sum;
410 			} else {
411 				size_t r = __fread((void *)va_arg(ap, char *), 1,
412 				    width, fp);
413 
414 				if (r == 0)
415 					goto input_failure;
416 				nread += r;
417 				nassigned++;
418 			}
419 			nconversions++;
420 			break;
421 
422 		case CT_CCL:
423 			/* scan a (nonempty) character class (sets NOSKIP) */
424 			if (width == 0)
425 				width = (size_t)~0;	/* `infinity' */
426 			/* take only those things in the class */
427 			if (flags & LONG) {
428 				wchar_t twc;
429 				int nchars;
430 
431 				if ((flags & SUPPRESS) == 0)
432 					wcp = va_arg(ap, wchar_t *);
433 				else
434 					wcp = &twc;
435 				n = 0;
436 				nchars = 0;
437 				while (width != 0) {
438 					if (n == MB_CUR_MAX) {
439 						fp->_flags |= __SERR;
440 						goto input_failure;
441 					}
442 					buf[n++] = *fp->_p;
443 					fp->_p++;
444 					fp->_r--;
445 					mbs = initial;
446 					nconv = mbrtowc(wcp, buf, n, &mbs);
447 					if (nconv == (size_t)-1) {
448 						fp->_flags |= __SERR;
449 						goto input_failure;
450 					}
451 					if (nconv == 0)
452 						*wcp = L'\0';
453 					if (nconv != (size_t)-2) {
454 						if (wctob(*wcp) != EOF &&
455 						    !ccltab[wctob(*wcp)]) {
456 							while (n != 0) {
457 								n--;
458 								__ungetc(buf[n],
459 								    fp);
460 							}
461 							break;
462 						}
463 						nread += n;
464 						width--;
465 						if (!(flags & SUPPRESS))
466 							wcp++;
467 						nchars++;
468 						n = 0;
469 					}
470 					if (fp->_r <= 0 && __srefill(fp)) {
471 						if (n != 0) {
472 							fp->_flags |= __SERR;
473 							goto input_failure;
474 						}
475 						break;
476 					}
477 				}
478 				if (n != 0) {
479 					fp->_flags |= __SERR;
480 					goto input_failure;
481 				}
482 				n = nchars;
483 				if (n == 0)
484 					goto match_failure;
485 				if (!(flags & SUPPRESS)) {
486 					*wcp = L'\0';
487 					nassigned++;
488 				}
489 			} else if (flags & SUPPRESS) {
490 				n = 0;
491 				while (ccltab[*fp->_p]) {
492 					n++, fp->_r--, fp->_p++;
493 					if (--width == 0)
494 						break;
495 					if (fp->_r <= 0 && __srefill(fp)) {
496 						if (n == 0)
497 							goto input_failure;
498 						break;
499 					}
500 				}
501 				if (n == 0)
502 					goto match_failure;
503 			} else {
504 				p0 = p = va_arg(ap, char *);
505 				while (ccltab[*fp->_p]) {
506 					fp->_r--;
507 					*p++ = *fp->_p++;
508 					if (--width == 0)
509 						break;
510 					if (fp->_r <= 0 && __srefill(fp)) {
511 						if (p == p0)
512 							goto input_failure;
513 						break;
514 					}
515 				}
516 				n = p - p0;
517 				if (n == 0)
518 					goto match_failure;
519 				*p = 0;
520 				nassigned++;
521 			}
522 			nread += n;
523 			nconversions++;
524 			break;
525 
526 		case CT_STRING:
527 			/* like CCL, but zero-length string OK, & no NOSKIP */
528 			if (width == 0)
529 				width = (size_t)~0;
530 			if (flags & LONG) {
531 				wchar_t twc;
532 
533 				if ((flags & SUPPRESS) == 0)
534 					wcp = va_arg(ap, wchar_t *);
535 				else
536 					wcp = &twc;
537 				n = 0;
538 				while (!isspace(*fp->_p) && width != 0) {
539 					if (n == MB_CUR_MAX) {
540 						fp->_flags |= __SERR;
541 						goto input_failure;
542 					}
543 					buf[n++] = *fp->_p;
544 					fp->_p++;
545 					fp->_r--;
546 					mbs = initial;
547 					nconv = mbrtowc(wcp, buf, n, &mbs);
548 					if (nconv == (size_t)-1) {
549 						fp->_flags |= __SERR;
550 						goto input_failure;
551 					}
552 					if (nconv == 0)
553 						*wcp = L'\0';
554 					if (nconv != (size_t)-2) {
555 						if (iswspace(*wcp)) {
556 							while (n != 0) {
557 								n--;
558 								__ungetc(buf[n],
559 								    fp);
560 							}
561 							break;
562 						}
563 						nread += n;
564 						width--;
565 						if (!(flags & SUPPRESS))
566 							wcp++;
567 						n = 0;
568 					}
569 					if (fp->_r <= 0 && __srefill(fp)) {
570 						if (n != 0) {
571 							fp->_flags |= __SERR;
572 							goto input_failure;
573 						}
574 						break;
575 					}
576 				}
577 				if (!(flags & SUPPRESS)) {
578 					*wcp = L'\0';
579 					nassigned++;
580 				}
581 			} else if (flags & SUPPRESS) {
582 				n = 0;
583 				while (!isspace(*fp->_p)) {
584 					n++, fp->_r--, fp->_p++;
585 					if (--width == 0)
586 						break;
587 					if (fp->_r <= 0 && __srefill(fp))
588 						break;
589 				}
590 				nread += n;
591 			} else {
592 				p0 = p = va_arg(ap, char *);
593 				while (!isspace(*fp->_p)) {
594 					fp->_r--;
595 					*p++ = *fp->_p++;
596 					if (--width == 0)
597 						break;
598 					if (fp->_r <= 0 && __srefill(fp))
599 						break;
600 				}
601 				*p = 0;
602 				nread += p - p0;
603 				nassigned++;
604 			}
605 			nconversions++;
606 			continue;
607 
608 		case CT_INT:
609 			/* scan an integer as if by the conversion function */
610 #ifdef hardway
611 			if (width == 0 || width > sizeof(buf) - 1)
612 				width = sizeof(buf) - 1;
613 #else
614 			/* size_t is unsigned, hence this optimisation */
615 			if (--width > sizeof(buf) - 2)
616 				width = sizeof(buf) - 2;
617 			width++;
618 #endif
619 			flags |= SIGNOK | NDIGITS | NZDIGITS;
620 			for (p = buf; width; width--) {
621 				c = *fp->_p;
622 				/*
623 				 * Switch on the character; `goto ok'
624 				 * if we accept it as a part of number.
625 				 */
626 				switch (c) {
627 
628 				/*
629 				 * The digit 0 is always legal, but is
630 				 * special.  For %i conversions, if no
631 				 * digits (zero or nonzero) have been
632 				 * scanned (only signs), we will have
633 				 * base==0.  In that case, we should set
634 				 * it to 8 and enable 0x prefixing.
635 				 * Also, if we have not scanned zero digits
636 				 * before this, do not turn off prefixing
637 				 * (someone else will turn it off if we
638 				 * have scanned any nonzero digits).
639 				 */
640 				case '0':
641 					if (base == 0) {
642 						base = 8;
643 						flags |= PFXOK;
644 					}
645 					if (flags & NZDIGITS)
646 					    flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
647 					else
648 					    flags &= ~(SIGNOK|PFXOK|NDIGITS);
649 					goto ok;
650 
651 				/* 1 through 7 always legal */
652 				case '1': case '2': case '3':
653 				case '4': case '5': case '6': case '7':
654 					base = basefix[base];
655 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
656 					goto ok;
657 
658 				/* digits 8 and 9 ok iff decimal or hex */
659 				case '8': case '9':
660 					base = basefix[base];
661 					if (base <= 8)
662 						break;	/* not legal here */
663 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
664 					goto ok;
665 
666 				/* letters ok iff hex */
667 				case 'A': case 'B': case 'C':
668 				case 'D': case 'E': case 'F':
669 				case 'a': case 'b': case 'c':
670 				case 'd': case 'e': case 'f':
671 					/* no need to fix base here */
672 					if (base <= 10)
673 						break;	/* not legal here */
674 					flags &= ~(SIGNOK | PFXOK | NDIGITS);
675 					goto ok;
676 
677 				/* sign ok only as first character */
678 				case '+': case '-':
679 					if (flags & SIGNOK) {
680 						flags &= ~SIGNOK;
681 						flags |= HAVESIGN;
682 						goto ok;
683 					}
684 					break;
685 
686 				/*
687 				 * x ok iff flag still set & 2nd char (or
688 				 * 3rd char if we have a sign).
689 				 */
690 				case 'x': case 'X':
691 					if (flags & PFXOK && p ==
692 					    buf + 1 + !!(flags & HAVESIGN)) {
693 						base = 16;	/* if %i */
694 						flags &= ~PFXOK;
695 						goto ok;
696 					}
697 					break;
698 				}
699 
700 				/*
701 				 * If we got here, c is not a legal character
702 				 * for a number.  Stop accumulating digits.
703 				 */
704 				break;
705 		ok:
706 				/*
707 				 * c is legal: store it and look at the next.
708 				 */
709 				*p++ = c;
710 				if (--fp->_r > 0)
711 					fp->_p++;
712 				else if (__srefill(fp))
713 					break;		/* EOF */
714 			}
715 			/*
716 			 * If we had only a sign, it is no good; push
717 			 * back the sign.  If the number ends in `x',
718 			 * it was [sign] '0' 'x', so push back the x
719 			 * and treat it as [sign] '0'.
720 			 */
721 			if (flags & NDIGITS) {
722 				if (p > buf)
723 					(void) __ungetc(*(u_char *)--p, fp);
724 				goto match_failure;
725 			}
726 			c = ((u_char *)p)[-1];
727 			if (c == 'x' || c == 'X') {
728 				--p;
729 				(void) __ungetc(c, fp);
730 			}
731 			if ((flags & SUPPRESS) == 0) {
732 				uintmax_t res;
733 
734 				*p = 0;
735 				if ((flags & UNSIGNED) == 0)
736 				    res = strtoimax(buf, (char **)NULL, base);
737 				else
738 				    res = strtoumax(buf, (char **)NULL, base);
739 				if (flags & POINTER)
740 					*va_arg(ap, void **) =
741 							(void *)(uintptr_t)res;
742 				else if (flags & SHORTSHORT)
743 					*va_arg(ap, char *) = res;
744 				else if (flags & SHORT)
745 					*va_arg(ap, short *) = res;
746 				else if (flags & LONG)
747 					*va_arg(ap, long *) = res;
748 				else if (flags & LONGLONG)
749 					*va_arg(ap, long long *) = res;
750 				else if (flags & INTMAXT)
751 					*va_arg(ap, intmax_t *) = res;
752 				else if (flags & PTRDIFFT)
753 					*va_arg(ap, ptrdiff_t *) = res;
754 				else if (flags & SIZET)
755 					*va_arg(ap, size_t *) = res;
756 				else
757 					*va_arg(ap, int *) = res;
758 				nassigned++;
759 			}
760 			nread += p - buf;
761 			nconversions++;
762 			break;
763 
764 #ifndef NO_FLOATING_POINT
765 		case CT_FLOAT:
766 			/* scan a floating point number as if by strtod */
767 			if (width == 0 || width > sizeof(buf) - 1)
768 				width = sizeof(buf) - 1;
769 			if ((width = parsefloat(fp, buf, buf + width)) == 0)
770 				goto match_failure;
771 			if ((flags & SUPPRESS) == 0) {
772 				if (flags & LONGDBL) {
773 					long double res = strtold(buf, &p);
774 					*va_arg(ap, long double *) = res;
775 				} else if (flags & LONG) {
776 					double res = strtod(buf, &p);
777 					*va_arg(ap, double *) = res;
778 				} else {
779 					float res = strtof(buf, &p);
780 					*va_arg(ap, float *) = res;
781 				}
782 				nassigned++;
783 			}
784 			nread += width;
785 			nconversions++;
786 			break;
787 #endif /* !NO_FLOATING_POINT */
788 		}
789 	}
790 input_failure:
791 	return (nconversions != 0 ? nassigned : EOF);
792 match_failure:
793 	return (nassigned);
794 }
795 
796 /*
797  * Fill in the given table from the scanset at the given format
798  * (just after `[').  Return a pointer to the character past the
799  * closing `]'.  The table has a 1 wherever characters should be
800  * considered part of the scanset.
801  */
802 static const u_char *
803 __sccl(tab, fmt)
804 	char *tab;
805 	const u_char *fmt;
806 {
807 	int c, n, v, i;
808 
809 	/* first `clear' the whole table */
810 	c = *fmt++;		/* first char hat => negated scanset */
811 	if (c == '^') {
812 		v = 1;		/* default => accept */
813 		c = *fmt++;	/* get new first char */
814 	} else
815 		v = 0;		/* default => reject */
816 
817 	/* XXX: Will not work if sizeof(tab*) > sizeof(char) */
818 	(void) memset(tab, v, 256);
819 
820 	if (c == 0)
821 		return (fmt - 1);/* format ended before closing ] */
822 
823 	/*
824 	 * Now set the entries corresponding to the actual scanset
825 	 * to the opposite of the above.
826 	 *
827 	 * The first character may be ']' (or '-') without being special;
828 	 * the last character may be '-'.
829 	 */
830 	v = 1 - v;
831 	for (;;) {
832 		tab[c] = v;		/* take character c */
833 doswitch:
834 		n = *fmt++;		/* and examine the next */
835 		switch (n) {
836 
837 		case 0:			/* format ended too soon */
838 			return (fmt - 1);
839 
840 		case '-':
841 			/*
842 			 * A scanset of the form
843 			 *	[01+-]
844 			 * is defined as `the digit 0, the digit 1,
845 			 * the character +, the character -', but
846 			 * the effect of a scanset such as
847 			 *	[a-zA-Z0-9]
848 			 * is implementation defined.  The V7 Unix
849 			 * scanf treats `a-z' as `the letters a through
850 			 * z', but treats `a-a' as `the letter a, the
851 			 * character -, and the letter a'.
852 			 *
853 			 * For compatibility, the `-' is not considerd
854 			 * to define a range if the character following
855 			 * it is either a close bracket (required by ANSI)
856 			 * or is not numerically greater than the character
857 			 * we just stored in the table (c).
858 			 */
859 			n = *fmt;
860 			if (n == ']'
861 			    || (__collate_load_error ? n < c :
862 				__collate_range_cmp (n, c) < 0
863 			       )
864 			   ) {
865 				c = '-';
866 				break;	/* resume the for(;;) */
867 			}
868 			fmt++;
869 			/* fill in the range */
870 			if (__collate_load_error) {
871 				do {
872 					tab[++c] = v;
873 				} while (c < n);
874 			} else {
875 				for (i = 0; i < 256; i ++)
876 					if (   __collate_range_cmp (c, i) < 0
877 					    && __collate_range_cmp (i, n) <= 0
878 					   )
879 						tab[i] = v;
880 			}
881 #if 1	/* XXX another disgusting compatibility hack */
882 			c = n;
883 			/*
884 			 * Alas, the V7 Unix scanf also treats formats
885 			 * such as [a-c-e] as `the letters a through e'.
886 			 * This too is permitted by the standard....
887 			 */
888 			goto doswitch;
889 #else
890 			c = *fmt++;
891 			if (c == 0)
892 				return (fmt - 1);
893 			if (c == ']')
894 				return (fmt);
895 #endif
896 			break;
897 
898 		case ']':		/* end of scanset */
899 			return (fmt);
900 
901 		default:		/* just another character */
902 			c = n;
903 			break;
904 		}
905 	}
906 	/* NOTREACHED */
907 }
908 
909 #ifndef NO_FLOATING_POINT
910 static int
911 parsefloat(FILE *fp, char *buf, char *end)
912 {
913 	char *commit, *p;
914 	int infnanpos = 0;
915 	enum {
916 		S_START, S_GOTSIGN, S_INF, S_NAN, S_MAYBEHEX,
917 		S_DIGITS, S_FRAC, S_EXP, S_EXPDIGITS
918 	} state = S_START;
919 	unsigned char c;
920 	char decpt = *localeconv()->decimal_point;
921 	_Bool gotmantdig = 0, ishex = 0;
922 
923 	/*
924 	 * We set commit = p whenever the string we have read so far
925 	 * constitutes a valid representation of a floating point
926 	 * number by itself.  At some point, the parse will complete
927 	 * or fail, and we will ungetc() back to the last commit point.
928 	 * To ensure that the file offset gets updated properly, it is
929 	 * always necessary to read at least one character that doesn't
930 	 * match; thus, we can't short-circuit "infinity" or "nan(...)".
931 	 */
932 	commit = buf - 1;
933 	for (p = buf; p < end; ) {
934 		c = *fp->_p;
935 reswitch:
936 		switch (state) {
937 		case S_START:
938 			state = S_GOTSIGN;
939 			if (c == '-' || c == '+')
940 				break;
941 			else
942 				goto reswitch;
943 		case S_GOTSIGN:
944 			switch (c) {
945 			case '0':
946 				state = S_MAYBEHEX;
947 				commit = p;
948 				break;
949 			case 'I':
950 			case 'i':
951 				state = S_INF;
952 				break;
953 			case 'N':
954 			case 'n':
955 				state = S_NAN;
956 				break;
957 			default:
958 				state = S_DIGITS;
959 				goto reswitch;
960 			}
961 			break;
962 		case S_INF:
963 			if (infnanpos > 6 ||
964 			    (c != "nfinity"[infnanpos] &&
965 			     c != "NFINITY"[infnanpos]))
966 				goto parsedone;
967 			if (infnanpos == 1 || infnanpos == 6)
968 				commit = p;	/* inf or infinity */
969 			infnanpos++;
970 			break;
971 		case S_NAN:
972 			switch (infnanpos) {
973 			case -1:	/* XXX kludge to deal with nan(...) */
974 				goto parsedone;
975 			case 0:
976 				if (c != 'A' && c != 'a')
977 					goto parsedone;
978 				break;
979 			case 1:
980 				if (c != 'N' && c != 'n')
981 					goto parsedone;
982 				else
983 					commit = p;
984 				break;
985 			case 2:
986 				if (c != '(')
987 					goto parsedone;
988 				break;
989 			default:
990 				if (c == ')') {
991 					commit = p;
992 					infnanpos = -2;
993 				} else if (!isalnum(c) && c != '_')
994 					goto parsedone;
995 				break;
996 			}
997 			infnanpos++;
998 			break;
999 		case S_MAYBEHEX:
1000 			state = S_DIGITS;
1001 			if (c == 'X' || c == 'x') {
1002 				ishex = 1;
1003 				break;
1004 			} else {	/* we saw a '0', but no 'x' */
1005 				gotmantdig = 1;
1006 				goto reswitch;
1007 			}
1008 		case S_DIGITS:
1009 			if ((ishex && isxdigit(c)) || isdigit(c))
1010 				gotmantdig = 1;
1011 			else {
1012 				state = S_FRAC;
1013 				if (c != decpt)
1014 					goto reswitch;
1015 			}
1016 			if (gotmantdig)
1017 				commit = p;
1018 			break;
1019 		case S_FRAC:
1020 			if (((c == 'E' || c == 'e') && !ishex) ||
1021 			    ((c == 'P' || c == 'p') && ishex)) {
1022 				if (!gotmantdig)
1023 					goto parsedone;
1024 				else
1025 					state = S_EXP;
1026 			} else if ((ishex && isxdigit(c)) || isdigit(c)) {
1027 				commit = p;
1028 				gotmantdig = 1;
1029 			} else
1030 				goto parsedone;
1031 			break;
1032 		case S_EXP:
1033 			state = S_EXPDIGITS;
1034 			if (c == '-' || c == '+')
1035 				break;
1036 			else
1037 				goto reswitch;
1038 		case S_EXPDIGITS:
1039 			if (isdigit(c))
1040 				commit = p;
1041 			else
1042 				goto parsedone;
1043 			break;
1044 		default:
1045 			abort();
1046 		}
1047 		*p++ = c;
1048 		if (--fp->_r > 0)
1049 			fp->_p++;
1050 		else if (__srefill(fp))
1051 			break;	/* EOF */
1052 	}
1053 
1054 parsedone:
1055 	while (commit < --p)
1056 		__ungetc(*(u_char *)p, fp);
1057 	*++commit = '\0';
1058 	return (commit - buf);
1059 }
1060 #endif
1061