vfscanf.c revision 1.25
1 /* $NetBSD: vfscanf.c,v 1.25 2000/01/21 19:56:07 mycroft Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 6/4/93"; 43 #else 44 __RCSID("$NetBSD: vfscanf.c,v 1.25 2000/01/21 19:56:07 mycroft Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include "namespace.h" 49 50 #include <assert.h> 51 #include <errno.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <ctype.h> 55 #if __STDC__ 56 #include <stdarg.h> 57 #else 58 #include <varargs.h> 59 #endif 60 61 #include "local.h" 62 63 #ifdef FLOATING_POINT 64 #include "floatio.h" 65 #endif 66 67 #define BUF 513 /* Maximum length of numeric string. */ 68 69 /* 70 * Flags used during conversion. 71 */ 72 #define LONG 0x01 /* l: long or double */ 73 #define LONGDBL 0x02 /* L: long double; unimplemented */ 74 #define SHORT 0x04 /* h: short */ 75 #define QUAD 0x08 /* q: quad */ 76 #define SUPPRESS 0x10 /* suppress assignment */ 77 #define POINTER 0x20 /* weird %p pointer (`fake hex') */ 78 #define NOSKIP 0x40 /* do not skip blanks */ 79 80 /* 81 * The following are used in numeric conversions only: 82 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; 83 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. 84 */ 85 #define SIGNOK 0x080 /* +/- is (still) legal */ 86 #define NDIGITS 0x100 /* no digits detected */ 87 88 #define DPTOK 0x200 /* (float) decimal point is still legal */ 89 #define EXPOK 0x400 /* (float) exponent (e+3, etc) still legal */ 90 91 #define PFXOK 0x200 /* 0x prefix is (still) legal */ 92 #define NZDIGITS 0x400 /* no zero digits detected */ 93 94 /* 95 * Conversion types. 96 */ 97 #define CT_CHAR 0 /* %c conversion */ 98 #define CT_CCL 1 /* %[...] conversion */ 99 #define CT_STRING 2 /* %s conversion */ 100 #define CT_INT 3 /* integer, i.e., strtoq or strtouq */ 101 #define CT_FLOAT 4 /* floating, i.e., strtod */ 102 103 #define u_char unsigned char 104 #define u_long unsigned long 105 106 static const u_char *__sccl __P((char *, const u_char *)); 107 108 /* 109 * vfscanf 110 */ 111 int 112 __svfscanf(fp, fmt0, ap) 113 FILE *fp; 114 const char *fmt0; 115 _BSD_VA_LIST_ ap; 116 { 117 const u_char *fmt = (const u_char *)fmt0; 118 int c; /* character from format, or conversion */ 119 size_t width; /* field width, or 0 */ 120 char *p; /* points into all kinds of strings */ 121 int n; /* handy integer */ 122 int flags; /* flags as defined above */ 123 char *p0; /* saves original value of p when necessary */ 124 int nassigned; /* number of fields assigned */ 125 int nread; /* number of characters consumed from fp */ 126 int base; /* base argument to strtoq/strtouq */ 127 u_quad_t (*ccfn) __P((const char *, char **, int)); 128 /* conversion function (strtoq/strtouq) */ 129 char ccltab[256]; /* character class table for %[...] */ 130 char buf[BUF]; /* buffer for numeric conversions */ 131 132 /* `basefix' is used to avoid `if' tests in the integer scanner */ 133 static const short basefix[17] = 134 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 135 136 _DIAGASSERT(fp != NULL); 137 _DIAGASSERT(fmt0 != NULL); 138 139 FLOCKFILE(fp); 140 141 nassigned = 0; 142 nread = 0; 143 base = 0; /* XXX just to keep gcc happy */ 144 ccfn = NULL; /* XXX just to keep gcc happy */ 145 for (;;) { 146 c = *fmt++; 147 if (c == 0) { 148 FUNLOCKFILE(fp); 149 return (nassigned); 150 } 151 if (isspace(c)) { 152 while ((fp->_r > 0 || __srefill(fp) == 0) && 153 isspace(*fp->_p)) 154 nread++, fp->_r--, fp->_p++; 155 continue; 156 } 157 if (c != '%') 158 goto literal; 159 width = 0; 160 flags = 0; 161 /* 162 * switch on the format. continue if done; 163 * break once format type is derived. 164 */ 165 again: c = *fmt++; 166 switch (c) { 167 case '%': 168 literal: 169 if (fp->_r <= 0 && __srefill(fp)) 170 goto input_failure; 171 if (*fp->_p != c) 172 goto match_failure; 173 fp->_r--, fp->_p++; 174 nread++; 175 continue; 176 177 case '*': 178 flags |= SUPPRESS; 179 goto again; 180 case 'L': 181 flags |= LONGDBL; 182 goto again; 183 case 'h': 184 flags |= SHORT; 185 goto again; 186 case 'l': 187 if (*fmt == 'l') { 188 fmt++; 189 flags |= QUAD; 190 } else { 191 flags |= LONG; 192 } 193 goto again; 194 case 'q': 195 flags |= QUAD; 196 goto again; 197 198 case '0': case '1': case '2': case '3': case '4': 199 case '5': case '6': case '7': case '8': case '9': 200 width = width * 10 + c - '0'; 201 goto again; 202 203 /* 204 * Conversions. 205 * Those marked `compat' are for 4.[123]BSD compatibility. 206 * 207 * (According to ANSI, E and X formats are supposed 208 * to the same as e and x. Sorry about that.) 209 */ 210 case 'D': /* compat */ 211 flags |= LONG; 212 /* FALLTHROUGH */ 213 case 'd': 214 c = CT_INT; 215 ccfn = (u_quad_t (*) __P((const char *, char **, int)))strtoq; 216 base = 10; 217 break; 218 219 case 'i': 220 c = CT_INT; 221 ccfn = (u_quad_t (*) __P((const char *, char **, int)))strtoq; 222 base = 0; 223 break; 224 225 case 'O': /* compat */ 226 flags |= LONG; 227 /* FALLTHROUGH */ 228 case 'o': 229 c = CT_INT; 230 ccfn = strtouq; 231 base = 8; 232 break; 233 234 case 'u': 235 c = CT_INT; 236 ccfn = strtouq; 237 base = 10; 238 break; 239 240 case 'X': 241 case 'x': 242 flags |= PFXOK; /* enable 0x prefixing */ 243 c = CT_INT; 244 ccfn = strtouq; 245 base = 16; 246 break; 247 248 #ifdef FLOATING_POINT 249 case 'E': 250 case 'G': 251 case 'e': 252 case 'f': 253 case 'g': 254 c = CT_FLOAT; 255 break; 256 #endif 257 258 case 's': 259 c = CT_STRING; 260 break; 261 262 case '[': 263 fmt = __sccl(ccltab, fmt); 264 flags |= NOSKIP; 265 c = CT_CCL; 266 break; 267 268 case 'c': 269 flags |= NOSKIP; 270 c = CT_CHAR; 271 break; 272 273 case 'p': /* pointer format is like hex */ 274 flags |= POINTER | PFXOK; 275 c = CT_INT; 276 ccfn = strtouq; 277 base = 16; 278 break; 279 280 case 'n': 281 if (flags & SUPPRESS) /* ??? */ 282 continue; 283 if (flags & SHORT) 284 *va_arg(ap, short *) = nread; 285 else if (flags & LONG) 286 *va_arg(ap, long *) = nread; 287 else 288 *va_arg(ap, int *) = nread; 289 continue; 290 291 /* 292 * Disgusting backwards compatibility hacks. XXX 293 */ 294 case '\0': /* compat */ 295 FUNLOCKFILE(fp); 296 return (EOF); 297 298 default: /* compat */ 299 if (isupper(c)) 300 flags |= LONG; 301 c = CT_INT; 302 ccfn = (u_quad_t (*) __P((const char *, char **, int)))strtoq; 303 base = 10; 304 break; 305 } 306 307 /* 308 * We have a conversion that requires input. 309 */ 310 if (fp->_r <= 0 && __srefill(fp)) 311 goto input_failure; 312 313 /* 314 * Consume leading white space, except for formats 315 * that suppress this. 316 */ 317 if ((flags & NOSKIP) == 0) { 318 while (isspace(*fp->_p)) { 319 nread++; 320 if (--fp->_r > 0) 321 fp->_p++; 322 else if (__srefill(fp)) 323 goto input_failure; 324 } 325 /* 326 * Note that there is at least one character in 327 * the buffer, so conversions that do not set NOSKIP 328 * ca no longer result in an input failure. 329 */ 330 } 331 332 /* 333 * Do the conversion. 334 */ 335 switch (c) { 336 337 case CT_CHAR: 338 /* scan arbitrary characters (sets NOSKIP) */ 339 if (width == 0) 340 width = 1; 341 if (flags & SUPPRESS) { 342 size_t sum = 0; 343 for (;;) { 344 if ((n = fp->_r) < width) { 345 sum += n; 346 width -= n; 347 fp->_p += n; 348 if (__srefill(fp)) { 349 if (sum == 0) 350 goto input_failure; 351 break; 352 } 353 } else { 354 sum += width; 355 fp->_r -= width; 356 fp->_p += width; 357 break; 358 } 359 } 360 nread += sum; 361 } else { 362 size_t r = fread((void *)va_arg(ap, char *), 1, 363 width, fp); 364 365 if (r == 0) 366 goto input_failure; 367 nread += r; 368 nassigned++; 369 } 370 break; 371 372 case CT_CCL: 373 /* scan a (nonempty) character class (sets NOSKIP) */ 374 if (width == 0) 375 width = ~0U; /* `infinity' */ 376 /* take only those things in the class */ 377 if (flags & SUPPRESS) { 378 n = 0; 379 while (ccltab[*fp->_p]) { 380 n++, fp->_r--, fp->_p++; 381 if (--width == 0) 382 break; 383 if (fp->_r <= 0 && __srefill(fp)) { 384 if (n == 0) 385 goto input_failure; 386 break; 387 } 388 } 389 if (n == 0) 390 goto match_failure; 391 } else { 392 p0 = p = va_arg(ap, char *); 393 while (ccltab[*fp->_p]) { 394 fp->_r--; 395 *p++ = *fp->_p++; 396 if (--width == 0) 397 break; 398 if (fp->_r <= 0 && __srefill(fp)) { 399 if (p == p0) 400 goto input_failure; 401 break; 402 } 403 } 404 n = p - p0; 405 if (n == 0) 406 goto match_failure; 407 *p = 0; 408 nassigned++; 409 } 410 nread += n; 411 break; 412 413 case CT_STRING: 414 /* like CCL, but zero-length string OK, & no NOSKIP */ 415 if (width == 0) 416 width = ~0U; 417 if (flags & SUPPRESS) { 418 n = 0; 419 while (!isspace(*fp->_p)) { 420 n++, fp->_r--, fp->_p++; 421 if (--width == 0) 422 break; 423 if (fp->_r <= 0 && __srefill(fp)) 424 break; 425 } 426 nread += n; 427 } else { 428 p0 = p = va_arg(ap, char *); 429 while (!isspace(*fp->_p)) { 430 fp->_r--; 431 *p++ = *fp->_p++; 432 if (--width == 0) 433 break; 434 if (fp->_r <= 0 && __srefill(fp)) 435 break; 436 } 437 *p = 0; 438 nread += p - p0; 439 nassigned++; 440 } 441 continue; 442 443 case CT_INT: 444 /* scan an integer as if by strtoq/strtouq */ 445 #ifdef hardway 446 if (width == 0 || width > sizeof(buf) - 1) 447 width = sizeof(buf) - 1; 448 #else 449 /* size_t is unsigned, hence this optimisation */ 450 if (--width > sizeof(buf) - 2) 451 width = sizeof(buf) - 2; 452 width++; 453 #endif 454 flags |= SIGNOK | NDIGITS | NZDIGITS; 455 for (p = buf; width; width--) { 456 c = *fp->_p; 457 /* 458 * Switch on the character; `goto ok' 459 * if we accept it as a part of number. 460 */ 461 switch (c) { 462 463 /* 464 * The digit 0 is always legal, but is 465 * special. For %i conversions, if no 466 * digits (zero or nonzero) have been 467 * scanned (only signs), we will have 468 * base==0. In that case, we should set 469 * it to 8 and enable 0x prefixing. 470 * Also, if we have not scanned zero digits 471 * before this, do not turn off prefixing 472 * (someone else will turn it off if we 473 * have scanned any nonzero digits). 474 */ 475 case '0': 476 if (base == 0) { 477 base = 8; 478 flags |= PFXOK; 479 } 480 if (flags & NZDIGITS) 481 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 482 else 483 flags &= ~(SIGNOK|PFXOK|NDIGITS); 484 goto ok; 485 486 /* 1 through 7 always legal */ 487 case '1': case '2': case '3': 488 case '4': case '5': case '6': case '7': 489 base = basefix[base]; 490 flags &= ~(SIGNOK | PFXOK | NDIGITS); 491 goto ok; 492 493 /* digits 8 and 9 ok iff decimal or hex */ 494 case '8': case '9': 495 base = basefix[base]; 496 if (base <= 8) 497 break; /* not legal here */ 498 flags &= ~(SIGNOK | PFXOK | NDIGITS); 499 goto ok; 500 501 /* letters ok iff hex */ 502 case 'A': case 'B': case 'C': 503 case 'D': case 'E': case 'F': 504 case 'a': case 'b': case 'c': 505 case 'd': case 'e': case 'f': 506 /* no need to fix base here */ 507 if (base <= 10) 508 break; /* not legal here */ 509 flags &= ~(SIGNOK | PFXOK | NDIGITS); 510 goto ok; 511 512 /* sign ok only as first character */ 513 case '+': case '-': 514 if (flags & SIGNOK) { 515 flags &= ~SIGNOK; 516 goto ok; 517 } 518 break; 519 520 /* x ok iff flag still set & 2nd char */ 521 case 'x': case 'X': 522 if (flags & PFXOK && p == buf + 1) { 523 base = 16; /* if %i */ 524 flags &= ~PFXOK; 525 goto ok; 526 } 527 break; 528 } 529 530 /* 531 * If we got here, c is not a legal character 532 * for a number. Stop accumulating digits. 533 */ 534 break; 535 ok: 536 /* 537 * c is legal: store it and look at the next. 538 */ 539 *p++ = c; 540 if (--fp->_r > 0) 541 fp->_p++; 542 else if (__srefill(fp)) 543 break; /* EOF */ 544 } 545 /* 546 * If we had only a sign, it is no good; push 547 * back the sign. If the number ends in `x', 548 * it was [sign] '0' 'x', so push back the x 549 * and treat it as [sign] '0'. 550 */ 551 if (flags & NDIGITS) { 552 if (p > buf) 553 (void) ungetc(*(u_char *)--p, fp); 554 goto match_failure; 555 } 556 c = ((u_char *)p)[-1]; 557 if (c == 'x' || c == 'X') { 558 --p; 559 (void) ungetc(c, fp); 560 } 561 if ((flags & SUPPRESS) == 0) { 562 u_quad_t res; 563 564 *p = 0; 565 res = (*ccfn)(buf, (char **)NULL, base); 566 if (flags & POINTER) 567 *va_arg(ap, void **) = 568 (void *)(long)res; 569 else if (flags & QUAD) 570 *va_arg(ap, quad_t *) = res; 571 else if (flags & LONG) 572 *va_arg(ap, long *) = (long)res; 573 else if (flags & SHORT) 574 *va_arg(ap, short *) = (short)res; 575 else 576 *va_arg(ap, int *) = (int)res; 577 nassigned++; 578 } 579 nread += p - buf; 580 break; 581 582 #ifdef FLOATING_POINT 583 case CT_FLOAT: 584 /* scan a floating point number as if by strtod */ 585 #ifdef hardway 586 if (width == 0 || width > sizeof(buf) - 1) 587 width = sizeof(buf) - 1; 588 #else 589 /* size_t is unsigned, hence this optimisation */ 590 if (--width > sizeof(buf) - 2) 591 width = sizeof(buf) - 2; 592 width++; 593 #endif 594 flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; 595 for (p = buf; width; width--) { 596 c = *fp->_p; 597 /* 598 * This code mimicks the integer conversion 599 * code, but is much simpler. 600 */ 601 switch (c) { 602 603 case '0': case '1': case '2': case '3': 604 case '4': case '5': case '6': case '7': 605 case '8': case '9': 606 flags &= ~(SIGNOK | NDIGITS); 607 goto fok; 608 609 case '+': case '-': 610 if (flags & SIGNOK) { 611 flags &= ~SIGNOK; 612 goto fok; 613 } 614 break; 615 case '.': 616 if (flags & DPTOK) { 617 flags &= ~(SIGNOK | DPTOK); 618 goto fok; 619 } 620 break; 621 case 'e': case 'E': 622 /* no exponent without some digits */ 623 if ((flags&(NDIGITS|EXPOK)) == EXPOK) { 624 flags = 625 (flags & ~(EXPOK|DPTOK)) | 626 SIGNOK | NDIGITS; 627 goto fok; 628 } 629 break; 630 } 631 break; 632 fok: 633 *p++ = c; 634 if (--fp->_r > 0) 635 fp->_p++; 636 else if (__srefill(fp)) 637 break; /* EOF */ 638 } 639 /* 640 * If no digits, might be missing exponent digits 641 * (just give back the exponent) or might be missing 642 * regular digits, but had sign and/or decimal point. 643 */ 644 if (flags & NDIGITS) { 645 if (flags & EXPOK) { 646 /* no digits at all */ 647 while (p > buf) 648 ungetc(*(u_char *)--p, fp); 649 goto match_failure; 650 } 651 /* just a bad exponent (e and maybe sign) */ 652 c = *(u_char *)--p; 653 if (c != 'e' && c != 'E') { 654 (void) ungetc(c, fp);/* sign */ 655 c = *(u_char *)--p; 656 } 657 (void) ungetc(c, fp); 658 } 659 if ((flags & SUPPRESS) == 0) { 660 double res; 661 662 *p = 0; 663 res = strtod(buf, (char **) NULL); 664 if (flags & LONGDBL) 665 *va_arg(ap, long double *) = res; 666 else if (flags & LONG) 667 *va_arg(ap, double *) = res; 668 else 669 *va_arg(ap, float *) = res; 670 nassigned++; 671 } 672 nread += p - buf; 673 break; 674 #endif /* FLOATING_POINT */ 675 } 676 } 677 input_failure: 678 FUNLOCKFILE(fp); 679 return (nassigned ? nassigned : EOF); 680 match_failure: 681 FUNLOCKFILE(fp); 682 return (nassigned); 683 } 684 685 /* 686 * Fill in the given table from the scanset at the given format 687 * (just after `['). Return a pointer to the character past the 688 * closing `]'. The table has a 1 wherever characters should be 689 * considered part of the scanset. 690 */ 691 static const u_char * 692 __sccl(tab, fmt) 693 char *tab; 694 const u_char *fmt; 695 { 696 int c, n, v; 697 698 _DIAGASSERT(tab != NULL); 699 _DIAGASSERT(fmt != NULL); 700 701 /* first `clear' the whole table */ 702 c = *fmt++; /* first char hat => negated scanset */ 703 if (c == '^') { 704 v = 1; /* default => accept */ 705 c = *fmt++; /* get new first char */ 706 } else 707 v = 0; /* default => reject */ 708 /* should probably use memset here */ 709 for (n = 0; n < 256; n++) 710 tab[n] = v; 711 if (c == 0) 712 return (fmt - 1);/* format ended before closing ] */ 713 714 /* 715 * Now set the entries corresponding to the actual scanset 716 * to the opposite of the above. 717 * 718 * The first character may be ']' (or '-') without being special; 719 * the last character may be '-'. 720 */ 721 v = 1 - v; 722 for (;;) { 723 tab[c] = v; /* take character c */ 724 doswitch: 725 n = *fmt++; /* and examine the next */ 726 switch (n) { 727 728 case 0: /* format ended too soon */ 729 return (fmt - 1); 730 731 case '-': 732 /* 733 * A scanset of the form 734 * [01+-] 735 * is defined as `the digit 0, the digit 1, 736 * the character +, the character -', but 737 * the effect of a scanset such as 738 * [a-zA-Z0-9] 739 * is implementation defined. The V7 Unix 740 * scanf treats `a-z' as `the letters a through 741 * z', but treats `a-a' as `the letter a, the 742 * character -, and the letter a'. 743 * 744 * For compatibility, the `-' is not considerd 745 * to define a range if the character following 746 * it is either a close bracket (required by ANSI) 747 * or is not numerically greater than the character 748 * we just stored in the table (c). 749 */ 750 n = *fmt; 751 if (n == ']' || n < c) { 752 c = '-'; 753 break; /* resume the for(;;) */ 754 } 755 fmt++; 756 do { /* fill in the range */ 757 tab[++c] = v; 758 } while (c < n); 759 #if 1 /* XXX another disgusting compatibility hack */ 760 /* 761 * Alas, the V7 Unix scanf also treats formats 762 * such as [a-c-e] as `the letters a through e'. 763 * This too is permitted by the standard.... 764 */ 765 goto doswitch; 766 #else 767 c = *fmt++; 768 if (c == 0) 769 return (fmt - 1); 770 if (c == ']') 771 return (fmt); 772 break; 773 #endif 774 775 case ']': /* end of scanset */ 776 return (fmt); 777 778 default: /* just another character */ 779 c = n; 780 break; 781 } 782 } 783 /* NOTREACHED */ 784 } 785
Indexes created Sun Sep 28 12:09:53 GMT 2025