vfscanf.c revision 50476
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 defined(LIBC_SCCS) && !defined(lint) 38#if 0 39static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 6/4/93"; 40#endif 41static const char rcsid[] = 42 "$FreeBSD: head/lib/libc/stdio/vfscanf.c 50476 1999-08-28 00:22:10Z peter $"; 43#endif /* LIBC_SCCS and not lint */ 44 45#include <stdio.h> 46#include <stdlib.h> 47#include <ctype.h> 48#if __STDC__ 49#include <stdarg.h> 50#else 51#include <varargs.h> 52#endif 53#include <string.h> 54 55#include "collate.h" 56#include "local.h" 57 58#define FLOATING_POINT 59 60#include "floatio.h" 61#define BUF 513 /* Maximum length of numeric string. */ 62 63/* 64 * Flags used during conversion. 65 */ 66#define LONG 0x01 /* l: long or double */ 67#define LONGDBL 0x02 /* L: long double */ 68#define SHORT 0x04 /* h: short */ 69#define SUPPRESS 0x08 /* suppress assignment */ 70#define POINTER 0x10 /* weird %p pointer (`fake hex') */ 71#define NOSKIP 0x20 /* do not skip blanks */ 72#define QUAD 0x400 73 74/* 75 * The following are used in numeric conversions only: 76 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; 77 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. 78 */ 79#define SIGNOK 0x40 /* +/- is (still) legal */ 80#define NDIGITS 0x80 /* no digits detected */ 81 82#define DPTOK 0x100 /* (float) decimal point is still legal */ 83#define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */ 84 85#define PFXOK 0x100 /* 0x prefix is (still) legal */ 86#define NZDIGITS 0x200 /* no zero digits detected */ 87 88/* 89 * Conversion types. 90 */ 91#define CT_CHAR 0 /* %c conversion */ 92#define CT_CCL 1 /* %[...] conversion */ 93#define CT_STRING 2 /* %s conversion */ 94#define CT_INT 3 /* integer, i.e., strtoq or strtouq */ 95#define CT_FLOAT 4 /* floating, i.e., strtod */ 96 97#define u_char unsigned char 98#define u_long unsigned long 99 100static u_char *__sccl(char *, u_char *); 101 102/* 103 * vfscanf 104 */ 105int 106__svfscanf(fp, fmt0, ap) 107 register FILE *fp; 108 char const *fmt0; 109 va_list ap; 110{ 111 register u_char *fmt = (u_char *)fmt0; 112 register int c; /* character from format, or conversion */ 113 register size_t width; /* field width, or 0 */ 114 register char *p; /* points into all kinds of strings */ 115 register int n; /* handy integer */ 116 register int flags; /* flags as defined above */ 117 register char *p0; /* saves original value of p when necessary */ 118 int nassigned; /* number of fields assigned */ 119 int nconversions; /* number of conversions */ 120 int nread; /* number of characters consumed from fp */ 121 int base; /* base argument to strtoq/strtouq */ 122 u_quad_t(*ccfn)(); /* conversion function (strtoq/strtouq) */ 123 char ccltab[256]; /* character class table for %[...] */ 124 char buf[BUF]; /* buffer for numeric conversions */ 125 126 /* `basefix' is used to avoid `if' tests in the integer scanner */ 127 static short basefix[17] = 128 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 129 130 nassigned = 0; 131 nconversions = 0; 132 nread = 0; 133 base = 0; /* XXX just to keep gcc happy */ 134 ccfn = NULL; /* XXX just to keep gcc happy */ 135 for (;;) { 136 c = *fmt++; 137 if (c == 0) 138 return (nassigned); 139 if (isspace(c)) { 140 while ((fp->_r > 0 || __srefill(fp) == 0) && isspace(*fp->_p)) 141 nread++, fp->_r--, fp->_p++; 142 continue; 143 } 144 if (c != '%') 145 goto literal; 146 width = 0; 147 flags = 0; 148 /* 149 * switch on the format. continue if done; 150 * break once format type is derived. 151 */ 152again: c = *fmt++; 153 switch (c) { 154 case '%': 155literal: 156 if (fp->_r <= 0 && __srefill(fp)) 157 goto input_failure; 158 if (*fp->_p != c) 159 goto match_failure; 160 fp->_r--, fp->_p++; 161 nread++; 162 continue; 163 164 case '*': 165 flags |= SUPPRESS; 166 goto again; 167 case 'l': 168 flags |= LONG; 169 goto again; 170 case 'q': 171 flags |= QUAD; 172 goto again; 173 case 'L': 174 flags |= LONGDBL; 175 goto again; 176 case 'h': 177 flags |= SHORT; 178 goto again; 179 180 case '0': case '1': case '2': case '3': case '4': 181 case '5': case '6': case '7': case '8': case '9': 182 width = width * 10 + c - '0'; 183 goto again; 184 185 /* 186 * Conversions. 187 * Those marked `compat' are for 4.[123]BSD compatibility. 188 * 189 * (According to ANSI, E and X formats are supposed 190 * to the same as e and x. Sorry about that.) 191 */ 192 case 'D': /* compat */ 193 flags |= LONG; 194 /* FALLTHROUGH */ 195 case 'd': 196 c = CT_INT; 197 ccfn = (u_quad_t (*)())strtoq; 198 base = 10; 199 break; 200 201 case 'i': 202 c = CT_INT; 203 ccfn = (u_quad_t (*)())strtoq; 204 base = 0; 205 break; 206 207 case 'O': /* compat */ 208 flags |= LONG; 209 /* FALLTHROUGH */ 210 case 'o': 211 c = CT_INT; 212 ccfn = strtouq; 213 base = 8; 214 break; 215 216 case 'u': 217 c = CT_INT; 218 ccfn = strtouq; 219 base = 10; 220 break; 221 222 case 'X': /* compat XXX */ 223 flags |= LONG; 224 /* FALLTHROUGH */ 225 case 'x': 226 flags |= PFXOK; /* enable 0x prefixing */ 227 c = CT_INT; 228 ccfn = strtouq; 229 base = 16; 230 break; 231 232#ifdef FLOATING_POINT 233 case 'E': /* compat XXX */ 234 case 'F': /* compat */ 235 flags |= LONG; 236 /* FALLTHROUGH */ 237 case 'e': case 'f': case 'g': 238 c = CT_FLOAT; 239 break; 240#endif 241 242 case 's': 243 c = CT_STRING; 244 break; 245 246 case '[': 247 fmt = __sccl(ccltab, fmt); 248 flags |= NOSKIP; 249 c = CT_CCL; 250 break; 251 252 case 'c': 253 flags |= NOSKIP; 254 c = CT_CHAR; 255 break; 256 257 case 'p': /* pointer format is like hex */ 258 flags |= POINTER | PFXOK; 259 c = CT_INT; 260 ccfn = strtouq; 261 base = 16; 262 break; 263 264 case 'n': 265 nconversions++; 266 if (flags & SUPPRESS) /* ??? */ 267 continue; 268 if (flags & SHORT) 269 *va_arg(ap, short *) = nread; 270 else if (flags & LONG) 271 *va_arg(ap, long *) = nread; 272 else if (flags & QUAD) 273 *va_arg(ap, quad_t *) = nread; 274 else 275 *va_arg(ap, int *) = nread; 276 continue; 277 278 /* 279 * Disgusting backwards compatibility hacks. XXX 280 */ 281 case '\0': /* compat */ 282 return (EOF); 283 284 default: /* compat */ 285 if (isupper(c)) 286 flags |= LONG; 287 c = CT_INT; 288 ccfn = (u_quad_t (*)())strtoq; 289 base = 10; 290 break; 291 } 292 293 /* 294 * We have a conversion that requires input. 295 */ 296 if (fp->_r <= 0 && __srefill(fp)) 297 goto input_failure; 298 299 /* 300 * Consume leading white space, except for formats 301 * that suppress this. 302 */ 303 if ((flags & NOSKIP) == 0) { 304 while (isspace(*fp->_p)) { 305 nread++; 306 if (--fp->_r > 0) 307 fp->_p++; 308 else if (__srefill(fp)) 309 goto input_failure; 310 } 311 /* 312 * Note that there is at least one character in 313 * the buffer, so conversions that do not set NOSKIP 314 * ca no longer result in an input failure. 315 */ 316 } 317 318 /* 319 * Do the conversion. 320 */ 321 switch (c) { 322 323 case CT_CHAR: 324 /* scan arbitrary characters (sets NOSKIP) */ 325 if (width == 0) 326 width = 1; 327 if (flags & SUPPRESS) { 328 size_t sum = 0; 329 for (;;) { 330 if ((n = fp->_r) < width) { 331 sum += n; 332 width -= n; 333 fp->_p += n; 334 if (__srefill(fp)) { 335 if (sum == 0) 336 goto input_failure; 337 break; 338 } 339 } else { 340 sum += width; 341 fp->_r -= width; 342 fp->_p += width; 343 break; 344 } 345 } 346 nread += sum; 347 } else { 348 size_t r = fread((void *)va_arg(ap, char *), 1, 349 width, fp); 350 351 if (r == 0) 352 goto input_failure; 353 nread += r; 354 nassigned++; 355 } 356 nconversions++; 357 break; 358 359 case CT_CCL: 360 /* scan a (nonempty) character class (sets NOSKIP) */ 361 if (width == 0) 362 width = (size_t)~0; /* `infinity' */ 363 /* take only those things in the class */ 364 if (flags & SUPPRESS) { 365 n = 0; 366 while (ccltab[*fp->_p]) { 367 n++, fp->_r--, fp->_p++; 368 if (--width == 0) 369 break; 370 if (fp->_r <= 0 && __srefill(fp)) { 371 if (n == 0) 372 goto input_failure; 373 break; 374 } 375 } 376 if (n == 0) 377 goto match_failure; 378 } else { 379 p0 = p = va_arg(ap, char *); 380 while (ccltab[*fp->_p]) { 381 fp->_r--; 382 *p++ = *fp->_p++; 383 if (--width == 0) 384 break; 385 if (fp->_r <= 0 && __srefill(fp)) { 386 if (p == p0) 387 goto input_failure; 388 break; 389 } 390 } 391 n = p - p0; 392 if (n == 0) 393 goto match_failure; 394 *p = 0; 395 nassigned++; 396 } 397 nread += n; 398 nconversions++; 399 break; 400 401 case CT_STRING: 402 /* like CCL, but zero-length string OK, & no NOSKIP */ 403 if (width == 0) 404 width = (size_t)~0; 405 if (flags & SUPPRESS) { 406 n = 0; 407 while (!isspace(*fp->_p)) { 408 n++, fp->_r--, fp->_p++; 409 if (--width == 0) 410 break; 411 if (fp->_r <= 0 && __srefill(fp)) 412 break; 413 } 414 nread += n; 415 } else { 416 p0 = p = va_arg(ap, char *); 417 while (!isspace(*fp->_p)) { 418 fp->_r--; 419 *p++ = *fp->_p++; 420 if (--width == 0) 421 break; 422 if (fp->_r <= 0 && __srefill(fp)) 423 break; 424 } 425 *p = 0; 426 nread += p - p0; 427 nassigned++; 428 } 429 nconversions++; 430 continue; 431 432 case CT_INT: 433 /* scan an integer as if by strtoq/strtouq */ 434#ifdef hardway 435 if (width == 0 || width > sizeof(buf) - 1) 436 width = sizeof(buf) - 1; 437#else 438 /* size_t is unsigned, hence this optimisation */ 439 if (--width > sizeof(buf) - 2) 440 width = sizeof(buf) - 2; 441 width++; 442#endif 443 flags |= SIGNOK | NDIGITS | NZDIGITS; 444 for (p = buf; width; width--) { 445 c = *fp->_p; 446 /* 447 * Switch on the character; `goto ok' 448 * if we accept it as a part of number. 449 */ 450 switch (c) { 451 452 /* 453 * The digit 0 is always legal, but is 454 * special. For %i conversions, if no 455 * digits (zero or nonzero) have been 456 * scanned (only signs), we will have 457 * base==0. In that case, we should set 458 * it to 8 and enable 0x prefixing. 459 * Also, if we have not scanned zero digits 460 * before this, do not turn off prefixing 461 * (someone else will turn it off if we 462 * have scanned any nonzero digits). 463 */ 464 case '0': 465 if (base == 0) { 466 base = 8; 467 flags |= PFXOK; 468 } 469 if (flags & NZDIGITS) 470 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 471 else 472 flags &= ~(SIGNOK|PFXOK|NDIGITS); 473 goto ok; 474 475 /* 1 through 7 always legal */ 476 case '1': case '2': case '3': 477 case '4': case '5': case '6': case '7': 478 base = basefix[base]; 479 flags &= ~(SIGNOK | PFXOK | NDIGITS); 480 goto ok; 481 482 /* digits 8 and 9 ok iff decimal or hex */ 483 case '8': case '9': 484 base = basefix[base]; 485 if (base <= 8) 486 break; /* not legal here */ 487 flags &= ~(SIGNOK | PFXOK | NDIGITS); 488 goto ok; 489 490 /* letters ok iff hex */ 491 case 'A': case 'B': case 'C': 492 case 'D': case 'E': case 'F': 493 case 'a': case 'b': case 'c': 494 case 'd': case 'e': case 'f': 495 /* no need to fix base here */ 496 if (base <= 10) 497 break; /* not legal here */ 498 flags &= ~(SIGNOK | PFXOK | NDIGITS); 499 goto ok; 500 501 /* sign ok only as first character */ 502 case '+': case '-': 503 if (flags & SIGNOK) { 504 flags &= ~SIGNOK; 505 goto ok; 506 } 507 break; 508 509 /* x ok iff flag still set & 2nd char */ 510 case 'x': case 'X': 511 if (flags & PFXOK && p == buf + 1) { 512 base = 16; /* if %i */ 513 flags &= ~PFXOK; 514 goto ok; 515 } 516 break; 517 } 518 519 /* 520 * If we got here, c is not a legal character 521 * for a number. Stop accumulating digits. 522 */ 523 break; 524 ok: 525 /* 526 * c is legal: store it and look at the next. 527 */ 528 *p++ = c; 529 if (--fp->_r > 0) 530 fp->_p++; 531 else if (__srefill(fp)) 532 break; /* EOF */ 533 } 534 /* 535 * If we had only a sign, it is no good; push 536 * back the sign. If the number ends in `x', 537 * it was [sign] '0' 'x', so push back the x 538 * and treat it as [sign] '0'. 539 */ 540 if (flags & NDIGITS) { 541 if (p > buf) 542 (void) ungetc(*(u_char *)--p, fp); 543 goto match_failure; 544 } 545 c = ((u_char *)p)[-1]; 546 if (c == 'x' || c == 'X') { 547 --p; 548 (void) ungetc(c, fp); 549 } 550 if ((flags & SUPPRESS) == 0) { 551 u_quad_t res; 552 553 *p = 0; 554 res = (*ccfn)(buf, (char **)NULL, base); 555 if (flags & POINTER) 556 *va_arg(ap, void **) = 557 (void *)(u_long)res; 558 else if (flags & SHORT) 559 *va_arg(ap, short *) = res; 560 else if (flags & LONG) 561 *va_arg(ap, long *) = res; 562 else if (flags & QUAD) 563 *va_arg(ap, quad_t *) = res; 564 else 565 *va_arg(ap, int *) = res; 566 nassigned++; 567 } 568 nread += p - buf; 569 nconversions++; 570 break; 571 572#ifdef FLOATING_POINT 573 case CT_FLOAT: 574 /* scan a floating point number as if by strtod */ 575#ifdef hardway 576 if (width == 0 || width > sizeof(buf) - 1) 577 width = sizeof(buf) - 1; 578#else 579 /* size_t is unsigned, hence this optimisation */ 580 if (--width > sizeof(buf) - 2) 581 width = sizeof(buf) - 2; 582 width++; 583#endif 584 flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; 585 for (p = buf; width; width--) { 586 c = *fp->_p; 587 /* 588 * This code mimicks the integer conversion 589 * code, but is much simpler. 590 */ 591 switch (c) { 592 593 case '0': case '1': case '2': case '3': 594 case '4': case '5': case '6': case '7': 595 case '8': case '9': 596 flags &= ~(SIGNOK | NDIGITS); 597 goto fok; 598 599 case '+': case '-': 600 if (flags & SIGNOK) { 601 flags &= ~SIGNOK; 602 goto fok; 603 } 604 break; 605 case '.': 606 if (flags & DPTOK) { 607 flags &= ~(SIGNOK | DPTOK); 608 goto fok; 609 } 610 break; 611 case 'e': case 'E': 612 /* no exponent without some digits */ 613 if ((flags&(NDIGITS|EXPOK)) == EXPOK) { 614 flags = 615 (flags & ~(EXPOK|DPTOK)) | 616 SIGNOK | NDIGITS; 617 goto fok; 618 } 619 break; 620 } 621 break; 622 fok: 623 *p++ = c; 624 if (--fp->_r > 0) 625 fp->_p++; 626 else if (__srefill(fp)) 627 break; /* EOF */ 628 } 629 /* 630 * If no digits, might be missing exponent digits 631 * (just give back the exponent) or might be missing 632 * regular digits, but had sign and/or decimal point. 633 */ 634 if (flags & NDIGITS) { 635 if (flags & EXPOK) { 636 /* no digits at all */ 637 while (p > buf) 638 ungetc(*(u_char *)--p, fp); 639 goto match_failure; 640 } 641 /* just a bad exponent (e and maybe sign) */ 642 c = *(u_char *)--p; 643 if (c != 'e' && c != 'E') { 644 (void) ungetc(c, fp);/* sign */ 645 c = *(u_char *)--p; 646 } 647 (void) ungetc(c, fp); 648 } 649 if ((flags & SUPPRESS) == 0) { 650 double res; 651 652 *p = 0; 653 /* XXX this loses precision for long doubles. */ 654 res = strtod(buf, (char **) NULL); 655 if (flags & LONGDBL) 656 *va_arg(ap, long double *) = res; 657 else if (flags & LONG) 658 *va_arg(ap, double *) = res; 659 else 660 *va_arg(ap, float *) = res; 661 nassigned++; 662 } 663 nread += p - buf; 664 nconversions++; 665 break; 666#endif /* FLOATING_POINT */ 667 } 668 } 669input_failure: 670 return (nconversions != 0 ? nassigned : EOF); 671match_failure: 672 return (nassigned); 673} 674 675/* 676 * Fill in the given table from the scanset at the given format 677 * (just after `['). Return a pointer to the character past the 678 * closing `]'. The table has a 1 wherever characters should be 679 * considered part of the scanset. 680 */ 681static u_char * 682__sccl(tab, fmt) 683 register char *tab; 684 register u_char *fmt; 685{ 686 register int c, n, v, i; 687 688 /* first `clear' the whole table */ 689 c = *fmt++; /* first char hat => negated scanset */ 690 if (c == '^') { 691 v = 1; /* default => accept */ 692 c = *fmt++; /* get new first char */ 693 } else 694 v = 0; /* default => reject */ 695 696 /* XXX: Will not work if sizeof(tab*) > sizeof(char) */ 697 (void) memset(tab, v, 256); 698 699 if (c == 0) 700 return (fmt - 1);/* format ended before closing ] */ 701 702 /* 703 * Now set the entries corresponding to the actual scanset 704 * to the opposite of the above. 705 * 706 * The first character may be ']' (or '-') without being special; 707 * the last character may be '-'. 708 */ 709 v = 1 - v; 710 for (;;) { 711 tab[c] = v; /* take character c */ 712doswitch: 713 n = *fmt++; /* and examine the next */ 714 switch (n) { 715 716 case 0: /* format ended too soon */ 717 return (fmt - 1); 718 719 case '-': 720 /* 721 * A scanset of the form 722 * [01+-] 723 * is defined as `the digit 0, the digit 1, 724 * the character +, the character -', but 725 * the effect of a scanset such as 726 * [a-zA-Z0-9] 727 * is implementation defined. The V7 Unix 728 * scanf treats `a-z' as `the letters a through 729 * z', but treats `a-a' as `the letter a, the 730 * character -, and the letter a'. 731 * 732 * For compatibility, the `-' is not considerd 733 * to define a range if the character following 734 * it is either a close bracket (required by ANSI) 735 * or is not numerically greater than the character 736 * we just stored in the table (c). 737 */ 738 n = *fmt; 739 if (n == ']' 740 || (__collate_load_error ? n < c : 741 __collate_range_cmp (n, c) < 0 742 ) 743 ) { 744 c = '-'; 745 break; /* resume the for(;;) */ 746 } 747 fmt++; 748 /* fill in the range */ 749 if (__collate_load_error) { 750 do { 751 tab[++c] = v; 752 } while (c < n); 753 } else { 754 for (i = 0; i < 256; i ++) 755 if ( __collate_range_cmp (c, i) < 0 756 && __collate_range_cmp (i, n) <= 0 757 ) 758 tab[i] = v; 759 } 760#if 1 /* XXX another disgusting compatibility hack */ 761 c = n; 762 /* 763 * Alas, the V7 Unix scanf also treats formats 764 * such as [a-c-e] as `the letters a through e'. 765 * This too is permitted by the standard.... 766 */ 767 goto doswitch; 768#else 769 c = *fmt++; 770 if (c == 0) 771 return (fmt - 1); 772 if (c == ']') 773 return (fmt); 774#endif 775 break; 776 777 case ']': /* end of scanset */ 778 return (fmt); 779 780 default: /* just another character */ 781 c = n; 782 break; 783 } 784 } 785 /* NOTREACHED */ 786} 787