vfscanf.c revision 1.16
1 /* $NetBSD: vfscanf.c,v 1.16 1997/07/13 20:15:35 christos 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 1.16 1997/07/13 20:15:35 christos Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include "namespace.h" 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <ctype.h> 52 #if __STDC__ 53 #include <stdarg.h> 54 #else 55 #include <varargs.h> 56 #endif 57 #include "local.h" 58 59 #ifdef FLOATING_POINT 60 #include "floatio.h" 61 #endif 62 63 #define BUF 513 /* Maximum length of numeric string. */ 64 65 /* 66 * Flags used during conversion. 67 */ 68 #define LONG 0x01 /* l: long or double */ 69 #define LONGDBL 0x02 /* L: long double; unimplemented */ 70 #define SHORT 0x04 /* h: short */ 71 #define QUAD 0x08 /* q: quad */ 72 #define SUPPRESS 0x10 /* suppress assignment */ 73 #define POINTER 0x20 /* weird %p pointer (`fake hex') */ 74 #define NOSKIP 0x40 /* do not skip blanks */ 75 76 /* 77 * The following are used in numeric conversions only: 78 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; 79 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. 80 */ 81 #define SIGNOK 0x080 /* +/- is (still) legal */ 82 #define NDIGITS 0x100 /* no digits detected */ 83 84 #define DPTOK 0x200 /* (float) decimal point is still legal */ 85 #define EXPOK 0x400 /* (float) exponent (e+3, etc) still legal */ 86 87 #define PFXOK 0x200 /* 0x prefix is (still) legal */ 88 #define NZDIGITS 0x400 /* no zero digits detected */ 89 90 /* 91 * Conversion types. 92 */ 93 #define CT_CHAR 0 /* %c conversion */ 94 #define CT_CCL 1 /* %[...] conversion */ 95 #define CT_STRING 2 /* %s conversion */ 96 #define CT_INT 3 /* integer, i.e., strtoq or strtouq */ 97 #define CT_FLOAT 4 /* floating, i.e., strtod */ 98 99 #define u_char unsigned char 100 #define u_long unsigned long 101 102 static u_char *__sccl __P((char *, u_char *)); 103 104 /* 105 * vfscanf 106 */ 107 int 108 __svfscanf(fp, fmt0, ap) 109 register FILE *fp; 110 char const *fmt0; 111 _BSD_VA_LIST_ ap; 112 { 113 register u_char *fmt = (u_char *)fmt0; 114 register int c; /* character from format, or conversion */ 115 register size_t width; /* field width, or 0 */ 116 register char *p; /* points into all kinds of strings */ 117 register int n; /* handy integer */ 118 register int flags; /* flags as defined above */ 119 register char *p0; /* saves original value of p when necessary */ 120 int nassigned; /* number of fields assigned */ 121 int nread; /* number of characters consumed from fp */ 122 int base; /* base argument to strtoq/strtouq */ 123 u_quad_t (*ccfn) __P((const char *, char **, int)); 124 /* conversion function (strtoq/strtouq) */ 125 char ccltab[256]; /* character class table for %[...] */ 126 char buf[BUF]; /* buffer for numeric conversions */ 127 128 /* `basefix' is used to avoid `if' tests in the integer scanner */ 129 static short basefix[17] = 130 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 131 132 nassigned = 0; 133 nread = 0; 134 base = 0; /* XXX just to keep gcc happy */ 135 ccfn = NULL; /* XXX just to keep gcc happy */ 136 for (;;) { 137 c = *fmt++; 138 if (c == 0) 139 return (nassigned); 140 if (isspace(c)) { 141 for (;;) { 142 if (fp->_r <= 0 && __srefill(fp)) 143 return (nassigned); 144 if (!isspace(*fp->_p)) 145 break; 146 nread++, fp->_r--, fp->_p++; 147 } 148 continue; 149 } 150 if (c != '%') 151 goto literal; 152 width = 0; 153 flags = 0; 154 /* 155 * switch on the format. continue if done; 156 * break once format type is derived. 157 */ 158 again: c = *fmt++; 159 switch (c) { 160 case '%': 161 literal: 162 if (fp->_r <= 0 && __srefill(fp)) 163 goto input_failure; 164 if (*fp->_p != c) 165 goto match_failure; 166 fp->_r--, fp->_p++; 167 nread++; 168 continue; 169 170 case '*': 171 flags |= SUPPRESS; 172 goto again; 173 case 'L': 174 flags |= LONGDBL; 175 goto again; 176 case 'h': 177 flags |= SHORT; 178 goto again; 179 case 'l': 180 if (*fmt == 'l') { 181 fmt++; 182 flags |= QUAD; 183 } else { 184 flags |= LONG; 185 } 186 goto again; 187 case 'q': 188 flags |= QUAD; 189 goto again; 190 191 case '0': case '1': case '2': case '3': case '4': 192 case '5': case '6': case '7': case '8': case '9': 193 width = width * 10 + c - '0'; 194 goto again; 195 196 /* 197 * Conversions. 198 * Those marked `compat' are for 4.[123]BSD compatibility. 199 * 200 * (According to ANSI, E and X formats are supposed 201 * to the same as e and x. Sorry about that.) 202 */ 203 case 'D': /* compat */ 204 flags |= LONG; 205 /* FALLTHROUGH */ 206 case 'd': 207 c = CT_INT; 208 ccfn = (u_quad_t (*) __P((const char *, char **, int)))strtoq; 209 base = 10; 210 break; 211 212 case 'i': 213 c = CT_INT; 214 ccfn = (u_quad_t (*) __P((const char *, char **, int)))strtoq; 215 base = 0; 216 break; 217 218 case 'O': /* compat */ 219 flags |= LONG; 220 /* FALLTHROUGH */ 221 case 'o': 222 c = CT_INT; 223 ccfn = strtouq; 224 base = 8; 225 break; 226 227 case 'u': 228 c = CT_INT; 229 ccfn = strtouq; 230 base = 10; 231 break; 232 233 case 'X': 234 case 'x': 235 flags |= PFXOK; /* enable 0x prefixing */ 236 c = CT_INT; 237 ccfn = strtouq; 238 base = 16; 239 break; 240 241 #ifdef FLOATING_POINT 242 case 'E': 243 case 'G': 244 case 'e': 245 case 'f': 246 case 'g': 247 c = CT_FLOAT; 248 break; 249 #endif 250 251 case 's': 252 c = CT_STRING; 253 break; 254 255 case '[': 256 fmt = __sccl(ccltab, fmt); 257 flags |= NOSKIP; 258 c = CT_CCL; 259 break; 260 261 case 'c': 262 flags |= NOSKIP; 263 c = CT_CHAR; 264 break; 265 266 case 'p': /* pointer format is like hex */ 267 flags |= POINTER | PFXOK; 268 c = CT_INT; 269 ccfn = strtouq; 270 base = 16; 271 break; 272 273 case 'n': 274 if (flags & SUPPRESS) /* ??? */ 275 continue; 276 if (flags & SHORT) 277 *va_arg(ap, short *) = nread; 278 else if (flags & LONG) 279 *va_arg(ap, long *) = nread; 280 else 281 *va_arg(ap, int *) = nread; 282 continue; 283 284 /* 285 * Disgusting backwards compatibility hacks. XXX 286 */ 287 case '\0': /* compat */ 288 return (EOF); 289 290 default: /* compat */ 291 if (isupper(c)) 292 flags |= LONG; 293 c = CT_INT; 294 ccfn = (u_quad_t (*) __P((const char *, char **, int)))strtoq; 295 base = 10; 296 break; 297 } 298 299 /* 300 * We have a conversion that requires input. 301 */ 302 if (fp->_r <= 0 && __srefill(fp)) 303 goto input_failure; 304 305 /* 306 * Consume leading white space, except for formats 307 * that suppress this. 308 */ 309 if ((flags & NOSKIP) == 0) { 310 while (isspace(*fp->_p)) { 311 nread++; 312 if (--fp->_r > 0) 313 fp->_p++; 314 else if (__srefill(fp)) 315 goto input_failure; 316 } 317 /* 318 * Note that there is at least one character in 319 * the buffer, so conversions that do not set NOSKIP 320 * ca no longer result in an input failure. 321 */ 322 } 323 324 /* 325 * Do the conversion. 326 */ 327 switch (c) { 328 329 case CT_CHAR: 330 /* scan arbitrary characters (sets NOSKIP) */ 331 if (width == 0) 332 width = 1; 333 if (flags & SUPPRESS) { 334 size_t sum = 0; 335 for (;;) { 336 if ((n = fp->_r) < width) { 337 sum += n; 338 width -= n; 339 fp->_p += n; 340 if (__srefill(fp)) { 341 if (sum == 0) 342 goto input_failure; 343 break; 344 } 345 } else { 346 sum += width; 347 fp->_r -= width; 348 fp->_p += width; 349 break; 350 } 351 } 352 nread += sum; 353 } else { 354 size_t r = fread((void *)va_arg(ap, char *), 1, 355 width, fp); 356 357 if (r == 0) 358 goto input_failure; 359 nread += r; 360 nassigned++; 361 } 362 break; 363 364 case CT_CCL: 365 /* scan a (nonempty) character class (sets NOSKIP) */ 366 if (width == 0) 367 width = ~0; /* `infinity' */ 368 /* take only those things in the class */ 369 if (flags & SUPPRESS) { 370 n = 0; 371 while (ccltab[*fp->_p]) { 372 n++, fp->_r--, fp->_p++; 373 if (--width == 0) 374 break; 375 if (fp->_r <= 0 && __srefill(fp)) { 376 if (n == 0) 377 goto input_failure; 378 break; 379 } 380 } 381 if (n == 0) 382 goto match_failure; 383 } else { 384 p0 = p = va_arg(ap, char *); 385 while (ccltab[*fp->_p]) { 386 fp->_r--; 387 *p++ = *fp->_p++; 388 if (--width == 0) 389 break; 390 if (fp->_r <= 0 && __srefill(fp)) { 391 if (p == p0) 392 goto input_failure; 393 break; 394 } 395 } 396 n = p - p0; 397 if (n == 0) 398 goto match_failure; 399 *p = 0; 400 nassigned++; 401 } 402 nread += n; 403 break; 404 405 case CT_STRING: 406 /* like CCL, but zero-length string OK, & no NOSKIP */ 407 if (width == 0) 408 width = ~0; 409 if (flags & SUPPRESS) { 410 n = 0; 411 while (!isspace(*fp->_p)) { 412 n++, fp->_r--, fp->_p++; 413 if (--width == 0) 414 break; 415 if (fp->_r <= 0 && __srefill(fp)) 416 break; 417 } 418 nread += n; 419 } else { 420 p0 = p = va_arg(ap, char *); 421 while (!isspace(*fp->_p)) { 422 fp->_r--; 423 *p++ = *fp->_p++; 424 if (--width == 0) 425 break; 426 if (fp->_r <= 0 && __srefill(fp)) 427 break; 428 } 429 *p = 0; 430 nread += p - p0; 431 nassigned++; 432 } 433 continue; 434 435 case CT_INT: 436 /* scan an integer as if by strtoq/strtouq */ 437 #ifdef hardway 438 if (width == 0 || width > sizeof(buf) - 1) 439 width = sizeof(buf) - 1; 440 #else 441 /* size_t is unsigned, hence this optimisation */ 442 if (--width > sizeof(buf) - 2) 443 width = sizeof(buf) - 2; 444 width++; 445 #endif 446 flags |= SIGNOK | NDIGITS | NZDIGITS; 447 for (p = buf; width; width--) { 448 c = *fp->_p; 449 /* 450 * Switch on the character; `goto ok' 451 * if we accept it as a part of number. 452 */ 453 switch (c) { 454 455 /* 456 * The digit 0 is always legal, but is 457 * special. For %i conversions, if no 458 * digits (zero or nonzero) have been 459 * scanned (only signs), we will have 460 * base==0. In that case, we should set 461 * it to 8 and enable 0x prefixing. 462 * Also, if we have not scanned zero digits 463 * before this, do not turn off prefixing 464 * (someone else will turn it off if we 465 * have scanned any nonzero digits). 466 */ 467 case '0': 468 if (base == 0) { 469 base = 8; 470 flags |= PFXOK; 471 } 472 if (flags & NZDIGITS) 473 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 474 else 475 flags &= ~(SIGNOK|PFXOK|NDIGITS); 476 goto ok; 477 478 /* 1 through 7 always legal */ 479 case '1': case '2': case '3': 480 case '4': case '5': case '6': case '7': 481 base = basefix[base]; 482 flags &= ~(SIGNOK | PFXOK | NDIGITS); 483 goto ok; 484 485 /* digits 8 and 9 ok iff decimal or hex */ 486 case '8': case '9': 487 base = basefix[base]; 488 if (base <= 8) 489 break; /* not legal here */ 490 flags &= ~(SIGNOK | PFXOK | NDIGITS); 491 goto ok; 492 493 /* letters ok iff hex */ 494 case 'A': case 'B': case 'C': 495 case 'D': case 'E': case 'F': 496 case 'a': case 'b': case 'c': 497 case 'd': case 'e': case 'f': 498 /* no need to fix base here */ 499 if (base <= 10) 500 break; /* not legal here */ 501 flags &= ~(SIGNOK | PFXOK | NDIGITS); 502 goto ok; 503 504 /* sign ok only as first character */ 505 case '+': case '-': 506 if (flags & SIGNOK) { 507 flags &= ~SIGNOK; 508 goto ok; 509 } 510 break; 511 512 /* x ok iff flag still set & 2nd char */ 513 case 'x': case 'X': 514 if (flags & PFXOK && p == buf + 1) { 515 base = 16; /* if %i */ 516 flags &= ~PFXOK; 517 goto ok; 518 } 519 break; 520 } 521 522 /* 523 * If we got here, c is not a legal character 524 * for a number. Stop accumulating digits. 525 */ 526 break; 527 ok: 528 /* 529 * c is legal: store it and look at the next. 530 */ 531 *p++ = c; 532 if (--fp->_r > 0) 533 fp->_p++; 534 else if (__srefill(fp)) 535 break; /* EOF */ 536 } 537 /* 538 * If we had only a sign, it is no good; push 539 * back the sign. If the number ends in `x', 540 * it was [sign] '0' 'x', so push back the x 541 * and treat it as [sign] '0'. 542 */ 543 if (flags & NDIGITS) { 544 if (p > buf) 545 (void) ungetc(*(u_char *)--p, fp); 546 goto match_failure; 547 } 548 c = ((u_char *)p)[-1]; 549 if (c == 'x' || c == 'X') { 550 --p; 551 (void) ungetc(c, fp); 552 } 553 if ((flags & SUPPRESS) == 0) { 554 u_quad_t res; 555 556 *p = 0; 557 res = (*ccfn)(buf, (char **)NULL, base); 558 if (flags & POINTER) 559 *va_arg(ap, void **) = 560 (void *)(long)res; 561 else if (flags & QUAD) 562 *va_arg(ap, quad_t *) = res; 563 else if (flags & LONG) 564 *va_arg(ap, long *) = res; 565 else if (flags & SHORT) 566 *va_arg(ap, short *) = res; 567 else 568 *va_arg(ap, int *) = res; 569 nassigned++; 570 } 571 nread += p - buf; 572 break; 573 574 #ifdef FLOATING_POINT 575 case CT_FLOAT: 576 /* scan a floating point number as if by strtod */ 577 #ifdef hardway 578 if (width == 0 || width > sizeof(buf) - 1) 579 width = sizeof(buf) - 1; 580 #else 581 /* size_t is unsigned, hence this optimisation */ 582 if (--width > sizeof(buf) - 2) 583 width = sizeof(buf) - 2; 584 width++; 585 #endif 586 flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; 587 for (p = buf; width; width--) { 588 c = *fp->_p; 589 /* 590 * This code mimicks the integer conversion 591 * code, but is much simpler. 592 */ 593 switch (c) { 594 595 case '0': case '1': case '2': case '3': 596 case '4': case '5': case '6': case '7': 597 case '8': case '9': 598 flags &= ~(SIGNOK | NDIGITS); 599 goto fok; 600 601 case '+': case '-': 602 if (flags & SIGNOK) { 603 flags &= ~SIGNOK; 604 goto fok; 605 } 606 break; 607 case '.': 608 if (flags & DPTOK) { 609 flags &= ~(SIGNOK | DPTOK); 610 goto fok; 611 } 612 break; 613 case 'e': case 'E': 614 /* no exponent without some digits */ 615 if ((flags&(NDIGITS|EXPOK)) == EXPOK) { 616 flags = 617 (flags & ~(EXPOK|DPTOK)) | 618 SIGNOK | NDIGITS; 619 goto fok; 620 } 621 break; 622 } 623 break; 624 fok: 625 *p++ = c; 626 if (--fp->_r > 0) 627 fp->_p++; 628 else if (__srefill(fp)) 629 break; /* EOF */ 630 } 631 /* 632 * If no digits, might be missing exponent digits 633 * (just give back the exponent) or might be missing 634 * regular digits, but had sign and/or decimal point. 635 */ 636 if (flags & NDIGITS) { 637 if (flags & EXPOK) { 638 /* no digits at all */ 639 while (p > buf) 640 ungetc(*(u_char *)--p, fp); 641 goto match_failure; 642 } 643 /* just a bad exponent (e and maybe sign) */ 644 c = *(u_char *)--p; 645 if (c != 'e' && c != 'E') { 646 (void) ungetc(c, fp);/* sign */ 647 c = *(u_char *)--p; 648 } 649 (void) ungetc(c, fp); 650 } 651 if ((flags & SUPPRESS) == 0) { 652 double res; 653 654 *p = 0; 655 res = strtod(buf, (char **) NULL); 656 if (flags & LONGDBL) 657 *va_arg(ap, long double *) = res; 658 else if (flags & LONG) 659 *va_arg(ap, double *) = res; 660 else 661 *va_arg(ap, float *) = res; 662 nassigned++; 663 } 664 nread += p - buf; 665 break; 666 #endif /* FLOATING_POINT */ 667 } 668 } 669 input_failure: 670 return (nassigned ? nassigned : -1); 671 match_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 */ 681 static u_char * 682 __sccl(tab, fmt) 683 register char *tab; 684 register u_char *fmt; 685 { 686 register int c, n, v; 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 /* should probably use memset here */ 696 for (n = 0; n < 256; n++) 697 tab[n] = v; 698 if (c == 0) 699 return (fmt - 1);/* format ended before closing ] */ 700 701 /* 702 * Now set the entries corresponding to the actual scanset 703 * to the opposite of the above. 704 * 705 * The first character may be ']' (or '-') without being special; 706 * the last character may be '-'. 707 */ 708 v = 1 - v; 709 for (;;) { 710 tab[c] = v; /* take character c */ 711 doswitch: 712 n = *fmt++; /* and examine the next */ 713 switch (n) { 714 715 case 0: /* format ended too soon */ 716 return (fmt - 1); 717 718 case '-': 719 /* 720 * A scanset of the form 721 * [01+-] 722 * is defined as `the digit 0, the digit 1, 723 * the character +, the character -', but 724 * the effect of a scanset such as 725 * [a-zA-Z0-9] 726 * is implementation defined. The V7 Unix 727 * scanf treats `a-z' as `the letters a through 728 * z', but treats `a-a' as `the letter a, the 729 * character -, and the letter a'. 730 * 731 * For compatibility, the `-' is not considerd 732 * to define a range if the character following 733 * it is either a close bracket (required by ANSI) 734 * or is not numerically greater than the character 735 * we just stored in the table (c). 736 */ 737 n = *fmt; 738 if (n == ']' || n < c) { 739 c = '-'; 740 break; /* resume the for(;;) */ 741 } 742 fmt++; 743 do { /* fill in the range */ 744 tab[++c] = v; 745 } while (c < n); 746 #if 1 /* XXX another disgusting compatibility hack */ 747 /* 748 * Alas, the V7 Unix scanf also treats formats 749 * such as [a-c-e] as `the letters a through e'. 750 * This too is permitted by the standard.... 751 */ 752 goto doswitch; 753 #else 754 c = *fmt++; 755 if (c == 0) 756 return (fmt - 1); 757 if (c == ']') 758 return (fmt); 759 #endif 760 break; 761 762 case ']': /* end of scanset */ 763 return (fmt); 764 765 default: /* just another character */ 766 c = n; 767 break; 768 } 769 } 770 /* NOTREACHED */ 771 } 772
Indexes created Wed Sep 24 02:09:48 GMT 2025