vfwscanf.c revision 149313
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#if 0 38#if defined(LIBC_SCCS) && !defined(lint) 39static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 6/4/93"; 40#endif /* LIBC_SCCS and not lint */ 41#endif 42#include <sys/cdefs.h> 43__FBSDID("$FreeBSD: head/lib/libc/stdio/vfwscanf.c 149313 2005-08-20 07:59:13Z stefanf $"); 44 45#include "namespace.h" 46#include <ctype.h> 47#include <inttypes.h> 48#include <limits.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#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 102static int parsefloat(FILE *, wchar_t *, wchar_t *); 103 104extern int __scanfdebug; 105 106#define INCCL(_c) \ 107 (cclcompl ? (wmemchr(ccls, (_c), ccle - ccls) == NULL) : \ 108 (wmemchr(ccls, (_c), ccle - ccls) != NULL)) 109 110/* 111 * MT-safe version. 112 */ 113int 114vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap) 115{ 116 int ret; 117 118 FLOCKFILE(fp); 119 ORIENT(fp, 1); 120 ret = __vfwscanf(fp, fmt, ap); 121 FUNLOCKFILE(fp); 122 return (ret); 123} 124 125/* 126 * Non-MT-safe version. 127 */ 128int 129__vfwscanf(FILE * __restrict fp, const wchar_t * __restrict fmt, va_list ap) 130{ 131 wint_t c; /* character from format, or conversion */ 132 size_t width; /* field width, or 0 */ 133 wchar_t *p; /* points into all kinds of strings */ 134 int n; /* handy integer */ 135 int flags; /* flags as defined above */ 136 wchar_t *p0; /* saves original value of p when necessary */ 137 int nassigned; /* number of fields assigned */ 138 int nconversions; /* number of conversions */ 139 int nread; /* number of characters consumed from fp */ 140 int base; /* base argument to conversion function */ 141 wchar_t buf[BUF]; /* buffer for numeric conversions */ 142 const wchar_t *ccls; /* character class start */ 143 const wchar_t *ccle; /* character class end */ 144 int cclcompl; /* ccl is complemented? */ 145 wint_t wi; /* handy wint_t */ 146 char *mbp; /* multibyte string pointer for %c %s %[ */ 147 size_t nconv; /* number of bytes in mb. conversion */ 148 char mbbuf[MB_LEN_MAX]; /* temporary mb. character buffer */ 149 static const mbstate_t initial; 150 mbstate_t mbs; 151 152 /* `basefix' is used to avoid `if' tests in the integer scanner */ 153 static short basefix[17] = 154 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 155 156 nassigned = 0; 157 nconversions = 0; 158 nread = 0; 159 ccls = ccle = NULL; 160 for (;;) { 161 c = *fmt++; 162 if (c == 0) 163 return (nassigned); 164 if (iswspace(c)) { 165 while ((c = __fgetwc(fp)) != WEOF && 166 iswspace(c)) 167 ; 168 if (c != WEOF) 169 __ungetwc(c, fp); 170 continue; 171 } 172 if (c != '%') 173 goto literal; 174 width = 0; 175 flags = 0; 176 /* 177 * switch on the format. continue if done; 178 * break once format type is derived. 179 */ 180again: c = *fmt++; 181 switch (c) { 182 case '%': 183literal: 184 if ((wi = __fgetwc(fp)) == WEOF) 185 goto input_failure; 186 if (wi != c) { 187 __ungetwc(wi, fp); 188 goto input_failure; 189 } 190 nread++; 191 continue; 192 193 case '*': 194 flags |= SUPPRESS; 195 goto again; 196 case 'j': 197 flags |= INTMAXT; 198 goto again; 199 case 'l': 200 if (flags & LONG) { 201 flags &= ~LONG; 202 flags |= LONGLONG; 203 } else 204 flags |= LONG; 205 goto again; 206 case 'q': 207 flags |= LONGLONG; /* not quite */ 208 goto again; 209 case 't': 210 flags |= PTRDIFFT; 211 goto again; 212 case 'z': 213 flags |= SIZET; 214 goto again; 215 case 'L': 216 flags |= LONGDBL; 217 goto again; 218 case 'h': 219 if (flags & SHORT) { 220 flags &= ~SHORT; 221 flags |= SHORTSHORT; 222 } else 223 flags |= SHORT; 224 goto again; 225 226 case '0': case '1': case '2': case '3': case '4': 227 case '5': case '6': case '7': case '8': case '9': 228 width = width * 10 + c - '0'; 229 goto again; 230 231 /* 232 * Conversions. 233 */ 234 case 'd': 235 c = CT_INT; 236 base = 10; 237 break; 238 239 case 'i': 240 c = CT_INT; 241 base = 0; 242 break; 243 244 case 'o': 245 c = CT_INT; 246 flags |= UNSIGNED; 247 base = 8; 248 break; 249 250 case 'u': 251 c = CT_INT; 252 flags |= UNSIGNED; 253 base = 10; 254 break; 255 256 case 'X': 257 case 'x': 258 flags |= PFXOK; /* enable 0x prefixing */ 259 c = CT_INT; 260 flags |= UNSIGNED; 261 base = 16; 262 break; 263 264#ifndef NO_FLOATING_POINT 265 case 'A': case 'E': case 'F': case 'G': 266 case 'a': case 'e': case 'f': case 'g': 267 c = CT_FLOAT; 268 break; 269#endif 270 271 case 'S': 272 flags |= LONG; 273 /* FALLTHROUGH */ 274 case 's': 275 c = CT_STRING; 276 break; 277 278 case '[': 279 ccls = fmt; 280 if (*fmt == '^') { 281 cclcompl = 1; 282 fmt++; 283 } else 284 cclcompl = 0; 285 if (*fmt == ']') 286 fmt++; 287 while (*fmt != '\0' && *fmt != ']') 288 fmt++; 289 ccle = fmt; 290 fmt++; 291 flags |= NOSKIP; 292 c = CT_CCL; 293 break; 294 295 case 'C': 296 flags |= LONG; 297 /* FALLTHROUGH */ 298 case 'c': 299 flags |= NOSKIP; 300 c = CT_CHAR; 301 break; 302 303 case 'p': /* pointer format is like hex */ 304 flags |= POINTER | PFXOK; 305 c = CT_INT; /* assumes sizeof(uintmax_t) */ 306 flags |= UNSIGNED; /* >= sizeof(uintptr_t) */ 307 base = 16; 308 break; 309 310 case 'n': 311 nconversions++; 312 if (flags & SUPPRESS) /* ??? */ 313 continue; 314 if (flags & SHORTSHORT) 315 *va_arg(ap, char *) = nread; 316 else if (flags & SHORT) 317 *va_arg(ap, short *) = nread; 318 else if (flags & LONG) 319 *va_arg(ap, long *) = nread; 320 else if (flags & LONGLONG) 321 *va_arg(ap, long long *) = nread; 322 else if (flags & INTMAXT) 323 *va_arg(ap, intmax_t *) = nread; 324 else if (flags & SIZET) 325 *va_arg(ap, size_t *) = nread; 326 else if (flags & PTRDIFFT) 327 *va_arg(ap, ptrdiff_t *) = nread; 328 else 329 *va_arg(ap, int *) = nread; 330 continue; 331 332 default: 333 goto match_failure; 334 335 /* 336 * Disgusting backwards compatibility hack. XXX 337 */ 338 case '\0': /* compat */ 339 return (EOF); 340 } 341 342 /* 343 * Consume leading white space, except for formats 344 * that suppress this. 345 */ 346 if ((flags & NOSKIP) == 0) { 347 while ((wi = __fgetwc(fp)) != WEOF && iswspace(wi)) 348 nread++; 349 if (wi == WEOF) 350 goto input_failure; 351 __ungetwc(wi, fp); 352 } 353 354 /* 355 * Do the conversion. 356 */ 357 switch (c) { 358 359 case CT_CHAR: 360 /* scan arbitrary characters (sets NOSKIP) */ 361 if (width == 0) 362 width = 1; 363 if (flags & LONG) { 364 if (!(flags & SUPPRESS)) 365 p = va_arg(ap, wchar_t *); 366 n = 0; 367 while (width-- != 0 && 368 (wi = __fgetwc(fp)) != WEOF) { 369 if (!(flags & SUPPRESS)) 370 *p++ = (wchar_t)wi; 371 n++; 372 } 373 if (n == 0) 374 goto input_failure; 375 nread += n; 376 if (!(flags & SUPPRESS)) 377 nassigned++; 378 } else { 379 if (!(flags & SUPPRESS)) 380 mbp = va_arg(ap, char *); 381 n = 0; 382 mbs = initial; 383 while (width != 0 && 384 (wi = __fgetwc(fp)) != WEOF) { 385 if (width >= MB_CUR_MAX && 386 !(flags & SUPPRESS)) { 387 nconv = wcrtomb(mbp, wi, &mbs); 388 if (nconv == (size_t)-1) 389 goto input_failure; 390 } else { 391 nconv = wcrtomb(mbbuf, wi, 392 &mbs); 393 if (nconv == (size_t)-1) 394 goto input_failure; 395 if (nconv > width) { 396 __ungetwc(wi, fp); 397 break; 398 } 399 if (!(flags & SUPPRESS)) 400 memcpy(mbp, mbbuf, 401 nconv); 402 } 403 if (!(flags & SUPPRESS)) 404 mbp += nconv; 405 width -= nconv; 406 n++; 407 } 408 if (n == 0) 409 goto input_failure; 410 nread += n; 411 if (!(flags & SUPPRESS)) 412 nassigned++; 413 } 414 nconversions++; 415 break; 416 417 case CT_CCL: 418 /* scan a (nonempty) character class (sets NOSKIP) */ 419 if (width == 0) 420 width = (size_t)~0; /* `infinity' */ 421 /* take only those things in the class */ 422 if ((flags & SUPPRESS) && (flags & LONG)) { 423 n = 0; 424 while ((wi = __fgetwc(fp)) != WEOF && 425 width-- != 0 && INCCL(wi)) 426 n++; 427 if (wi != WEOF) 428 __ungetwc(wi, fp); 429 if (n == 0) 430 goto match_failure; 431 } else if (flags & LONG) { 432 p0 = p = va_arg(ap, wchar_t *); 433 while ((wi = __fgetwc(fp)) != WEOF && 434 width-- != 0 && INCCL(wi)) 435 *p++ = (wchar_t)wi; 436 if (wi != WEOF) 437 __ungetwc(wi, fp); 438 n = p - p0; 439 if (n == 0) 440 goto match_failure; 441 *p = 0; 442 nassigned++; 443 } else { 444 if (!(flags & SUPPRESS)) 445 mbp = va_arg(ap, char *); 446 n = 0; 447 mbs = initial; 448 while ((wi = __fgetwc(fp)) != WEOF && 449 width != 0 && INCCL(wi)) { 450 if (width >= MB_CUR_MAX && 451 !(flags & SUPPRESS)) { 452 nconv = wcrtomb(mbp, wi, &mbs); 453 if (nconv == (size_t)-1) 454 goto input_failure; 455 } else { 456 nconv = wcrtomb(mbbuf, wi, 457 &mbs); 458 if (nconv == (size_t)-1) 459 goto input_failure; 460 if (nconv > width) 461 break; 462 if (!(flags & SUPPRESS)) 463 memcpy(mbp, mbbuf, 464 nconv); 465 } 466 if (!(flags & SUPPRESS)) 467 mbp += nconv; 468 width -= nconv; 469 n++; 470 } 471 if (wi != WEOF) 472 __ungetwc(wi, fp); 473 if (!(flags & SUPPRESS)) { 474 *mbp = 0; 475 nassigned++; 476 } 477 } 478 nread += n; 479 nconversions++; 480 break; 481 482 case CT_STRING: 483 /* like CCL, but zero-length string OK, & no NOSKIP */ 484 if (width == 0) 485 width = (size_t)~0; 486 if ((flags & SUPPRESS) && (flags & LONG)) { 487 while ((wi = __fgetwc(fp)) != WEOF && 488 width-- != 0 && 489 !iswspace(wi)) 490 nread++; 491 if (wi != WEOF) 492 __ungetwc(wi, fp); 493 } else if (flags & LONG) { 494 p0 = p = va_arg(ap, wchar_t *); 495 while ((wi = __fgetwc(fp)) != WEOF && 496 width-- != 0 && 497 !iswspace(wi)) { 498 *p++ = (wchar_t)wi; 499 nread++; 500 } 501 if (wi != WEOF) 502 __ungetwc(wi, fp); 503 *p = '\0'; 504 nassigned++; 505 } else { 506 if (!(flags & SUPPRESS)) 507 mbp = va_arg(ap, char *); 508 mbs = initial; 509 while ((wi = __fgetwc(fp)) != WEOF && 510 width != 0 && 511 !iswspace(wi)) { 512 if (width >= MB_CUR_MAX && 513 !(flags & SUPPRESS)) { 514 nconv = wcrtomb(mbp, wi, &mbs); 515 if (nconv == (size_t)-1) 516 goto input_failure; 517 } else { 518 nconv = wcrtomb(mbbuf, wi, 519 &mbs); 520 if (nconv == (size_t)-1) 521 goto input_failure; 522 if (nconv > width) 523 break; 524 if (!(flags & SUPPRESS)) 525 memcpy(mbp, mbbuf, 526 nconv); 527 } 528 if (!(flags & SUPPRESS)) 529 mbp += nconv; 530 width -= nconv; 531 nread++; 532 } 533 if (wi != WEOF) 534 __ungetwc(wi, fp); 535 if (!(flags & SUPPRESS)) { 536 *mbp = 0; 537 nassigned++; 538 } 539 } 540 nconversions++; 541 continue; 542 543 case CT_INT: 544 /* scan an integer as if by the conversion function */ 545 if (width == 0 || width > sizeof(buf) / 546 sizeof(*buf) - 1) 547 width = sizeof(buf) / sizeof(*buf) - 1; 548 flags |= SIGNOK | NDIGITS | NZDIGITS; 549 for (p = buf; width; width--) { 550 c = __fgetwc(fp); 551 /* 552 * Switch on the character; `goto ok' 553 * if we accept it as a part of number. 554 */ 555 switch (c) { 556 557 /* 558 * The digit 0 is always legal, but is 559 * special. For %i conversions, if no 560 * digits (zero or nonzero) have been 561 * scanned (only signs), we will have 562 * base==0. In that case, we should set 563 * it to 8 and enable 0x prefixing. 564 * Also, if we have not scanned zero digits 565 * before this, do not turn off prefixing 566 * (someone else will turn it off if we 567 * have scanned any nonzero digits). 568 */ 569 case '0': 570 if (base == 0) { 571 base = 8; 572 flags |= PFXOK; 573 } 574 if (flags & NZDIGITS) 575 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 576 else 577 flags &= ~(SIGNOK|PFXOK|NDIGITS); 578 goto ok; 579 580 /* 1 through 7 always legal */ 581 case '1': case '2': case '3': 582 case '4': case '5': case '6': case '7': 583 base = basefix[base]; 584 flags &= ~(SIGNOK | PFXOK | NDIGITS); 585 goto ok; 586 587 /* digits 8 and 9 ok iff decimal or hex */ 588 case '8': case '9': 589 base = basefix[base]; 590 if (base <= 8) 591 break; /* not legal here */ 592 flags &= ~(SIGNOK | PFXOK | NDIGITS); 593 goto ok; 594 595 /* letters ok iff hex */ 596 case 'A': case 'B': case 'C': 597 case 'D': case 'E': case 'F': 598 case 'a': case 'b': case 'c': 599 case 'd': case 'e': case 'f': 600 /* no need to fix base here */ 601 if (base <= 10) 602 break; /* not legal here */ 603 flags &= ~(SIGNOK | PFXOK | NDIGITS); 604 goto ok; 605 606 /* sign ok only as first character */ 607 case '+': case '-': 608 if (flags & SIGNOK) { 609 flags &= ~SIGNOK; 610 flags |= HAVESIGN; 611 goto ok; 612 } 613 break; 614 615 /* 616 * x ok iff flag still set & 2nd char (or 617 * 3rd char if we have a sign). 618 */ 619 case 'x': case 'X': 620 if (flags & PFXOK && p == 621 buf + 1 + !!(flags & HAVESIGN)) { 622 base = 16; /* if %i */ 623 flags &= ~PFXOK; 624 goto ok; 625 } 626 break; 627 } 628 629 /* 630 * If we got here, c is not a legal character 631 * for a number. Stop accumulating digits. 632 */ 633 if (c != WEOF) 634 __ungetwc(c, fp); 635 break; 636 ok: 637 /* 638 * c is legal: store it and look at the next. 639 */ 640 *p++ = (wchar_t)c; 641 } 642 /* 643 * If we had only a sign, it is no good; push 644 * back the sign. If the number ends in `x', 645 * it was [sign] '0' 'x', so push back the x 646 * and treat it as [sign] '0'. 647 */ 648 if (flags & NDIGITS) { 649 if (p > buf) 650 __ungetwc(*--p, fp); 651 goto match_failure; 652 } 653 c = p[-1]; 654 if (c == 'x' || c == 'X') { 655 --p; 656 __ungetwc(c, fp); 657 } 658 if ((flags & SUPPRESS) == 0) { 659 uintmax_t res; 660 661 *p = 0; 662 if ((flags & UNSIGNED) == 0) 663 res = wcstoimax(buf, NULL, base); 664 else 665 res = wcstoumax(buf, NULL, base); 666 if (flags & POINTER) 667 *va_arg(ap, void **) = 668 (void *)(uintptr_t)res; 669 else if (flags & SHORTSHORT) 670 *va_arg(ap, char *) = res; 671 else if (flags & SHORT) 672 *va_arg(ap, short *) = res; 673 else if (flags & LONG) 674 *va_arg(ap, long *) = res; 675 else if (flags & LONGLONG) 676 *va_arg(ap, long long *) = res; 677 else if (flags & INTMAXT) 678 *va_arg(ap, intmax_t *) = res; 679 else if (flags & PTRDIFFT) 680 *va_arg(ap, ptrdiff_t *) = res; 681 else if (flags & SIZET) 682 *va_arg(ap, size_t *) = res; 683 else 684 *va_arg(ap, int *) = res; 685 nassigned++; 686 } 687 nread += p - buf; 688 nconversions++; 689 break; 690 691#ifndef NO_FLOATING_POINT 692 case CT_FLOAT: 693 /* scan a floating point number as if by strtod */ 694 if (width == 0 || width > sizeof(buf) / 695 sizeof(*buf) - 1) 696 width = sizeof(buf) / sizeof(*buf) - 1; 697 if ((width = parsefloat(fp, buf, buf + width)) == 0) 698 goto match_failure; 699 if ((flags & SUPPRESS) == 0) { 700 if (flags & LONGDBL) { 701 long double res = wcstold(buf, &p); 702 *va_arg(ap, long double *) = res; 703 } else if (flags & LONG) { 704 double res = wcstod(buf, &p); 705 *va_arg(ap, double *) = res; 706 } else { 707 float res = wcstof(buf, &p); 708 *va_arg(ap, float *) = res; 709 } 710 if (__scanfdebug && p - buf != width) 711 abort(); 712 nassigned++; 713 } 714 nread += width; 715 nconversions++; 716 break; 717#endif /* !NO_FLOATING_POINT */ 718 } 719 } 720input_failure: 721 return (nconversions != 0 ? nassigned : EOF); 722match_failure: 723 return (nassigned); 724} 725 726#ifndef NO_FLOATING_POINT 727static int 728parsefloat(FILE *fp, wchar_t *buf, wchar_t *end) 729{ 730 wchar_t *commit, *p; 731 int infnanpos = 0; 732 enum { 733 S_START, S_GOTSIGN, S_INF, S_NAN, S_MAYBEHEX, 734 S_DIGITS, S_FRAC, S_EXP, S_EXPDIGITS 735 } state = S_START; 736 wchar_t c; 737 wchar_t decpt = (wchar_t)(unsigned char)*localeconv()->decimal_point; 738 _Bool gotmantdig = 0, ishex = 0; 739 740 /* 741 * We set commit = p whenever the string we have read so far 742 * constitutes a valid representation of a floating point 743 * number by itself. At some point, the parse will complete 744 * or fail, and we will ungetc() back to the last commit point. 745 * To ensure that the file offset gets updated properly, it is 746 * always necessary to read at least one character that doesn't 747 * match; thus, we can't short-circuit "infinity" or "nan(...)". 748 */ 749 commit = buf - 1; 750 c = WEOF; 751 for (p = buf; p < end; ) { 752 if ((c = __fgetwc(fp)) == WEOF) 753 break; 754reswitch: 755 switch (state) { 756 case S_START: 757 state = S_GOTSIGN; 758 if (c == '-' || c == '+') 759 break; 760 else 761 goto reswitch; 762 case S_GOTSIGN: 763 switch (c) { 764 case '0': 765 state = S_MAYBEHEX; 766 commit = p; 767 break; 768 case 'I': 769 case 'i': 770 state = S_INF; 771 break; 772 case 'N': 773 case 'n': 774 state = S_NAN; 775 break; 776 default: 777 state = S_DIGITS; 778 goto reswitch; 779 } 780 break; 781 case S_INF: 782 if (infnanpos > 6 || 783 (c != "nfinity"[infnanpos] && 784 c != "NFINITY"[infnanpos])) 785 goto parsedone; 786 if (infnanpos == 1 || infnanpos == 6) 787 commit = p; /* inf or infinity */ 788 infnanpos++; 789 break; 790 case S_NAN: 791 switch (infnanpos) { 792 case -1: /* XXX kludge to deal with nan(...) */ 793 goto parsedone; 794 case 0: 795 if (c != 'A' && c != 'a') 796 goto parsedone; 797 break; 798 case 1: 799 if (c != 'N' && c != 'n') 800 goto parsedone; 801 else 802 commit = p; 803 break; 804 case 2: 805 if (c != '(') 806 goto parsedone; 807 break; 808 default: 809 if (c == ')') { 810 commit = p; 811 infnanpos = -2; 812 } else if (!iswalnum(c) && c != '_') 813 goto parsedone; 814 break; 815 } 816 infnanpos++; 817 break; 818 case S_MAYBEHEX: 819 state = S_DIGITS; 820 if (c == 'X' || c == 'x') { 821 ishex = 1; 822 break; 823 } else { /* we saw a '0', but no 'x' */ 824 gotmantdig = 1; 825 goto reswitch; 826 } 827 case S_DIGITS: 828 if ((ishex && iswxdigit(c)) || iswdigit(c)) 829 gotmantdig = 1; 830 else { 831 state = S_FRAC; 832 if (c != decpt) 833 goto reswitch; 834 } 835 if (gotmantdig) 836 commit = p; 837 break; 838 case S_FRAC: 839 if (((c == 'E' || c == 'e') && !ishex) || 840 ((c == 'P' || c == 'p') && ishex)) { 841 if (!gotmantdig) 842 goto parsedone; 843 else 844 state = S_EXP; 845 } else if ((ishex && iswxdigit(c)) || iswdigit(c)) { 846 commit = p; 847 gotmantdig = 1; 848 } else 849 goto parsedone; 850 break; 851 case S_EXP: 852 state = S_EXPDIGITS; 853 if (c == '-' || c == '+') 854 break; 855 else 856 goto reswitch; 857 case S_EXPDIGITS: 858 if (iswdigit(c)) 859 commit = p; 860 else 861 goto parsedone; 862 break; 863 default: 864 abort(); 865 } 866 *p++ = c; 867 c = WEOF; 868 } 869 870parsedone: 871 if (c != WEOF) 872 __ungetwc(c, fp); 873 while (commit < --p) 874 __ungetwc(*p, fp); 875 *++commit = '\0'; 876 return (commit - buf); 877} 878#endif 879