vfscanf.c revision 1.4
1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * 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 static char sccsid[] = "@(#)vfscanf.c 5.7 (Berkeley) 12/14/92"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <ctype.h> 44 #if __STDC__ 45 #include <stdarg.h> 46 #else 47 #include <varargs.h> 48 #endif 49 #include "local.h" 50 51 #define FLOATING_POINT 52 53 #include "floatio.h" 54 #define BUF 513 /* Maximum length of numeric string. */ 55 56 /* 57 * Flags used during conversion. 58 */ 59 #define LONG 0x01 /* l: long or double */ 60 #define LONGDBL 0x02 /* L: long double; unimplemented */ 61 #define SHORT 0x04 /* h: short */ 62 #define SUPPRESS 0x08 /* suppress assignment */ 63 #define POINTER 0x10 /* weird %p pointer (`fake hex') */ 64 #define NOSKIP 0x20 /* do not skip blanks */ 65 66 /* 67 * The following are used in numeric conversions only: 68 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; 69 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. 70 */ 71 #define SIGNOK 0x40 /* +/- is (still) legal */ 72 #define NDIGITS 0x80 /* no digits detected */ 73 74 #define DPTOK 0x100 /* (float) decimal point is still legal */ 75 #define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */ 76 77 #define PFXOK 0x100 /* 0x prefix is (still) legal */ 78 #define NZDIGITS 0x200 /* no zero digits detected */ 79 80 /* 81 * Conversion types. 82 */ 83 #define CT_CHAR 0 /* %c conversion */ 84 #define CT_CCL 1 /* %[...] conversion */ 85 #define CT_STRING 2 /* %s conversion */ 86 #define CT_INT 3 /* integer, i.e., strtol or strtoul */ 87 #define CT_FLOAT 4 /* floating, i.e., strtod */ 88 89 #define u_char unsigned char 90 #define u_long unsigned long 91 92 static u_char *__sccl(); 93 94 /* 95 * vfscanf 96 */ 97 __svfscanf(fp, fmt0, ap) 98 register FILE *fp; 99 char const *fmt0; 100 _VA_LIST_ ap; 101 { 102 register u_char *fmt = (u_char *)fmt0; 103 register int c; /* character from format, or conversion */ 104 register size_t width; /* field width, or 0 */ 105 register char *p; /* points into all kinds of strings */ 106 register int n; /* handy integer */ 107 register int flags; /* flags as defined above */ 108 register char *p0; /* saves original value of p when necessary */ 109 int nassigned; /* number of fields assigned */ 110 int nread; /* number of characters consumed from fp */ 111 int base; /* base argument to strtol/strtoul */ 112 u_long (*ccfn)(); /* conversion function (strtol/strtoul) */ 113 char ccltab[256]; /* character class table for %[...] */ 114 char buf[BUF]; /* buffer for numeric conversions */ 115 116 /* `basefix' is used to avoid `if' tests in the integer scanner */ 117 static short basefix[17] = 118 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 119 120 nassigned = 0; 121 nread = 0; 122 base = 0; /* XXX just to keep gcc happy */ 123 ccfn = NULL; /* XXX just to keep gcc happy */ 124 for (;;) { 125 c = *fmt++; 126 if (c == 0) 127 return (nassigned); 128 if (isspace(c)) { 129 for (;;) { 130 if (fp->_r <= 0 && __srefill(fp)) 131 return (nassigned); 132 if (!isspace(*fp->_p)) 133 break; 134 nread++, fp->_r--, fp->_p++; 135 } 136 continue; 137 } 138 if (c != '%') 139 goto literal; 140 width = 0; 141 flags = 0; 142 /* 143 * switch on the format. continue if done; 144 * break once format type is derived. 145 */ 146 again: c = *fmt++; 147 switch (c) { 148 case '%': 149 literal: 150 if (fp->_r <= 0 && __srefill(fp)) 151 goto input_failure; 152 if (*fp->_p != c) 153 goto match_failure; 154 fp->_r--, fp->_p++; 155 nread++; 156 continue; 157 158 case '*': 159 flags |= SUPPRESS; 160 goto again; 161 case 'l': 162 flags |= LONG; 163 goto again; 164 case 'L': 165 flags |= LONGDBL; 166 goto again; 167 case 'h': 168 flags |= SHORT; 169 goto again; 170 171 case '0': case '1': case '2': case '3': case '4': 172 case '5': case '6': case '7': case '8': case '9': 173 width = width * 10 + c - '0'; 174 goto again; 175 176 /* 177 * Conversions. 178 * Those marked `compat' are for 4.[123]BSD compatibility. 179 * 180 * (According to ANSI, E and X formats are supposed 181 * to the same as e and x. Sorry about that.) 182 */ 183 case 'D': /* compat */ 184 flags |= LONG; 185 /* FALLTHROUGH */ 186 case 'd': 187 c = CT_INT; 188 ccfn = (u_long (*)())strtol; 189 base = 10; 190 break; 191 192 case 'i': 193 c = CT_INT; 194 ccfn = (u_long (*)())strtol; 195 base = 0; 196 break; 197 198 case 'O': /* compat */ 199 flags |= LONG; 200 /* FALLTHROUGH */ 201 case 'o': 202 c = CT_INT; 203 ccfn = strtoul; 204 base = 8; 205 break; 206 207 case 'u': 208 c = CT_INT; 209 ccfn = strtoul; 210 base = 10; 211 break; 212 213 case 'X': /* compat XXX */ 214 flags |= LONG; 215 /* FALLTHROUGH */ 216 case 'x': 217 flags |= PFXOK; /* enable 0x prefixing */ 218 c = CT_INT; 219 ccfn = strtoul; 220 base = 16; 221 break; 222 223 #ifdef FLOATING_POINT 224 case 'E': /* compat XXX */ 225 case 'F': /* compat */ 226 flags |= LONG; 227 /* FALLTHROUGH */ 228 case 'e': case 'f': case 'g': 229 c = CT_FLOAT; 230 break; 231 #endif 232 233 case 's': 234 c = CT_STRING; 235 break; 236 237 case '[': 238 fmt = __sccl(ccltab, fmt); 239 flags |= NOSKIP; 240 c = CT_CCL; 241 break; 242 243 case 'c': 244 flags |= NOSKIP; 245 c = CT_CHAR; 246 break; 247 248 case 'p': /* pointer format is like hex */ 249 flags |= POINTER | PFXOK; 250 c = CT_INT; 251 ccfn = strtoul; 252 base = 16; 253 break; 254 255 case 'n': 256 if (flags & SUPPRESS) /* ??? */ 257 continue; 258 if (flags & SHORT) 259 *va_arg(ap, short *) = nread; 260 else if (flags & LONG) 261 *va_arg(ap, long *) = nread; 262 else 263 *va_arg(ap, int *) = nread; 264 continue; 265 266 /* 267 * Disgusting backwards compatibility hacks. XXX 268 */ 269 case '\0': /* compat */ 270 return (EOF); 271 272 default: /* compat */ 273 if (isupper(c)) 274 flags |= LONG; 275 c = CT_INT; 276 ccfn = (u_long (*)())strtol; 277 base = 10; 278 break; 279 } 280 281 /* 282 * We have a conversion that requires input. 283 */ 284 if (fp->_r <= 0 && __srefill(fp)) 285 goto input_failure; 286 287 /* 288 * Consume leading white space, except for formats 289 * that suppress this. 290 */ 291 if ((flags & NOSKIP) == 0) { 292 while (isspace(*fp->_p)) { 293 nread++; 294 if (--fp->_r > 0) 295 fp->_p++; 296 else if (__srefill(fp)) 297 goto input_failure; 298 } 299 /* 300 * Note that there is at least one character in 301 * the buffer, so conversions that do not set NOSKIP 302 * ca no longer result in an input failure. 303 */ 304 } 305 306 /* 307 * Do the conversion. 308 */ 309 switch (c) { 310 311 case CT_CHAR: 312 /* scan arbitrary characters (sets NOSKIP) */ 313 if (width == 0) 314 width = 1; 315 if (flags & SUPPRESS) { 316 size_t sum = 0; 317 for (;;) { 318 if ((n = fp->_r) < width) { 319 sum += n; 320 width -= n; 321 fp->_p += n; 322 if (__srefill(fp)) { 323 if (sum == 0) 324 goto input_failure; 325 break; 326 } 327 } else { 328 sum += width; 329 fp->_r -= width; 330 fp->_p += width; 331 break; 332 } 333 } 334 nread += sum; 335 } else { 336 size_t r = fread((void *)va_arg(ap, char *), 1, 337 width, fp); 338 339 if (r == 0) 340 goto input_failure; 341 nread += r; 342 nassigned++; 343 } 344 break; 345 346 case CT_CCL: 347 /* scan a (nonempty) character class (sets NOSKIP) */ 348 if (width == 0) 349 width = ~0; /* `infinity' */ 350 /* take only those things in the class */ 351 if (flags & SUPPRESS) { 352 n = 0; 353 while (ccltab[*fp->_p]) { 354 n++, fp->_r--, fp->_p++; 355 if (--width == 0) 356 break; 357 if (fp->_r <= 0 && __srefill(fp)) { 358 if (n == 0) 359 goto input_failure; 360 break; 361 } 362 } 363 if (n == 0) 364 goto match_failure; 365 } else { 366 p0 = p = va_arg(ap, char *); 367 while (ccltab[*fp->_p]) { 368 fp->_r--; 369 *p++ = *fp->_p++; 370 if (--width == 0) 371 break; 372 if (fp->_r <= 0 && __srefill(fp)) { 373 if (p == p0) 374 goto input_failure; 375 break; 376 } 377 } 378 n = p - p0; 379 if (n == 0) 380 goto match_failure; 381 *p = 0; 382 nassigned++; 383 } 384 nread += n; 385 break; 386 387 case CT_STRING: 388 /* like CCL, but zero-length string OK, & no NOSKIP */ 389 if (width == 0) 390 width = ~0; 391 if (flags & SUPPRESS) { 392 n = 0; 393 while (!isspace(*fp->_p)) { 394 n++, fp->_r--, fp->_p++; 395 if (--width == 0) 396 break; 397 if (fp->_r <= 0 && __srefill(fp)) 398 break; 399 } 400 nread += n; 401 } else { 402 p0 = p = va_arg(ap, char *); 403 while (!isspace(*fp->_p)) { 404 fp->_r--; 405 *p++ = *fp->_p++; 406 if (--width == 0) 407 break; 408 if (fp->_r <= 0 && __srefill(fp)) 409 break; 410 } 411 *p = 0; 412 nread += p - p0; 413 nassigned++; 414 } 415 continue; 416 417 case CT_INT: 418 /* scan an integer as if by strtol/strtoul */ 419 #ifdef hardway 420 if (width == 0 || width > sizeof(buf) - 1) 421 width = sizeof(buf) - 1; 422 #else 423 /* size_t is unsigned, hence this optimisation */ 424 if (--width > sizeof(buf) - 2) 425 width = sizeof(buf) - 2; 426 width++; 427 #endif 428 flags |= SIGNOK | NDIGITS | NZDIGITS; 429 for (p = buf; width; width--) { 430 c = *fp->_p; 431 /* 432 * Switch on the character; `goto ok' 433 * if we accept it as a part of number. 434 */ 435 switch (c) { 436 437 /* 438 * The digit 0 is always legal, but is 439 * special. For %i conversions, if no 440 * digits (zero or nonzero) have been 441 * scanned (only signs), we will have 442 * base==0. In that case, we should set 443 * it to 8 and enable 0x prefixing. 444 * Also, if we have not scanned zero digits 445 * before this, do not turn off prefixing 446 * (someone else will turn it off if we 447 * have scanned any nonzero digits). 448 */ 449 case '0': 450 if (base == 0) { 451 base = 8; 452 flags |= PFXOK; 453 } 454 if (flags & NZDIGITS) 455 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 456 else 457 flags &= ~(SIGNOK|PFXOK|NDIGITS); 458 goto ok; 459 460 /* 1 through 7 always legal */ 461 case '1': case '2': case '3': 462 case '4': case '5': case '6': case '7': 463 base = basefix[base]; 464 flags &= ~(SIGNOK | PFXOK | NDIGITS); 465 goto ok; 466 467 /* digits 8 and 9 ok iff decimal or hex */ 468 case '8': case '9': 469 base = basefix[base]; 470 if (base <= 8) 471 break; /* not legal here */ 472 flags &= ~(SIGNOK | PFXOK | NDIGITS); 473 goto ok; 474 475 /* letters ok iff hex */ 476 case 'A': case 'B': case 'C': 477 case 'D': case 'E': case 'F': 478 case 'a': case 'b': case 'c': 479 case 'd': case 'e': case 'f': 480 /* no need to fix base here */ 481 if (base <= 10) 482 break; /* not legal here */ 483 flags &= ~(SIGNOK | PFXOK | NDIGITS); 484 goto ok; 485 486 /* sign ok only as first character */ 487 case '+': case '-': 488 if (flags & SIGNOK) { 489 flags &= ~SIGNOK; 490 goto ok; 491 } 492 break; 493 494 /* x ok iff flag still set & 2nd char */ 495 case 'x': case 'X': 496 if (flags & PFXOK && p == buf + 1) { 497 base = 16; /* if %i */ 498 flags &= ~PFXOK; 499 goto ok; 500 } 501 break; 502 } 503 504 /* 505 * If we got here, c is not a legal character 506 * for a number. Stop accumulating digits. 507 */ 508 break; 509 ok: 510 /* 511 * c is legal: store it and look at the next. 512 */ 513 *p++ = c; 514 if (--fp->_r > 0) 515 fp->_p++; 516 else if (__srefill(fp)) 517 break; /* EOF */ 518 } 519 /* 520 * If we had only a sign, it is no good; push 521 * back the sign. If the number ends in `x', 522 * it was [sign] '0' 'x', so push back the x 523 * and treat it as [sign] '0'. 524 */ 525 if (flags & NDIGITS) { 526 if (p > buf) 527 (void) ungetc(*(u_char *)--p, fp); 528 goto match_failure; 529 } 530 c = ((u_char *)p)[-1]; 531 if (c == 'x' || c == 'X') { 532 --p; 533 (void) ungetc(c, fp); 534 } 535 if ((flags & SUPPRESS) == 0) { 536 u_long res; 537 538 *p = 0; 539 res = (*ccfn)(buf, (char **)NULL, base); 540 if (flags & POINTER) 541 *va_arg(ap, void **) = (void *)res; 542 else if (flags & SHORT) 543 *va_arg(ap, short *) = res; 544 else if (flags & LONG) 545 *va_arg(ap, long *) = res; 546 else 547 *va_arg(ap, int *) = res; 548 nassigned++; 549 } 550 nread += p - buf; 551 break; 552 553 #ifdef FLOATING_POINT 554 case CT_FLOAT: 555 /* scan a floating point number as if by strtod */ 556 #ifdef hardway 557 if (width == 0 || width > sizeof(buf) - 1) 558 width = sizeof(buf) - 1; 559 #else 560 /* size_t is unsigned, hence this optimisation */ 561 if (--width > sizeof(buf) - 2) 562 width = sizeof(buf) - 2; 563 width++; 564 #endif 565 flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; 566 for (p = buf; width; width--) { 567 c = *fp->_p; 568 /* 569 * This code mimicks the integer conversion 570 * code, but is much simpler. 571 */ 572 switch (c) { 573 574 case '0': case '1': case '2': case '3': 575 case '4': case '5': case '6': case '7': 576 case '8': case '9': 577 flags &= ~(SIGNOK | NDIGITS); 578 goto fok; 579 580 case '+': case '-': 581 if (flags & SIGNOK) { 582 flags &= ~SIGNOK; 583 goto fok; 584 } 585 break; 586 case '.': 587 if (flags & DPTOK) { 588 flags &= ~(SIGNOK | DPTOK); 589 goto fok; 590 } 591 break; 592 case 'e': case 'E': 593 /* no exponent without some digits */ 594 if ((flags&(NDIGITS|EXPOK)) == EXPOK) { 595 flags = 596 (flags & ~(EXPOK|DPTOK)) | 597 SIGNOK | NDIGITS; 598 goto fok; 599 } 600 break; 601 } 602 break; 603 fok: 604 *p++ = c; 605 if (--fp->_r > 0) 606 fp->_p++; 607 else if (__srefill(fp)) 608 break; /* EOF */ 609 } 610 /* 611 * If no digits, might be missing exponent digits 612 * (just give back the exponent) or might be missing 613 * regular digits, but had sign and/or decimal point. 614 */ 615 if (flags & NDIGITS) { 616 if (flags & EXPOK) { 617 /* no digits at all */ 618 while (p > buf) 619 ungetc(*(u_char *)--p, fp); 620 goto match_failure; 621 } 622 /* just a bad exponent (e and maybe sign) */ 623 c = *(u_char *)--p; 624 if (c != 'e' && c != 'E') { 625 (void) ungetc(c, fp);/* sign */ 626 c = *(u_char *)--p; 627 } 628 (void) ungetc(c, fp); 629 } 630 if ((flags & SUPPRESS) == 0) { 631 double res; 632 633 *p = 0; 634 res = strtod(buf, (char **) NULL); 635 if (flags & LONG) 636 *va_arg(ap, double *) = res; 637 else 638 *va_arg(ap, float *) = res; 639 nassigned++; 640 } 641 nread += p - buf; 642 break; 643 #endif /* FLOATING_POINT */ 644 } 645 } 646 input_failure: 647 return (nassigned ? nassigned : -1); 648 match_failure: 649 return (nassigned); 650 } 651 652 /* 653 * Fill in the given table from the scanset at the given format 654 * (just after `['). Return a pointer to the character past the 655 * closing `]'. The table has a 1 wherever characters should be 656 * considered part of the scanset. 657 */ 658 static u_char * 659 __sccl(tab, fmt) 660 register char *tab; 661 register u_char *fmt; 662 { 663 register int c, n, v; 664 665 /* first `clear' the whole table */ 666 c = *fmt++; /* first char hat => negated scanset */ 667 if (c == '^') { 668 v = 1; /* default => accept */ 669 c = *fmt++; /* get new first char */ 670 } else 671 v = 0; /* default => reject */ 672 /* should probably use memset here */ 673 for (n = 0; n < 256; n++) 674 tab[n] = v; 675 if (c == 0) 676 return (fmt - 1);/* format ended before closing ] */ 677 678 /* 679 * Now set the entries corresponding to the actual scanset 680 * to the opposite of the above. 681 * 682 * The first character may be ']' (or '-') without being special; 683 * the last character may be '-'. 684 */ 685 v = 1 - v; 686 for (;;) { 687 tab[c] = v; /* take character c */ 688 doswitch: 689 n = *fmt++; /* and examine the next */ 690 switch (n) { 691 692 case 0: /* format ended too soon */ 693 return (fmt - 1); 694 695 case '-': 696 /* 697 * A scanset of the form 698 * [01+-] 699 * is defined as `the digit 0, the digit 1, 700 * the character +, the character -', but 701 * the effect of a scanset such as 702 * [a-zA-Z0-9] 703 * is implementation defined. The V7 Unix 704 * scanf treats `a-z' as `the letters a through 705 * z', but treats `a-a' as `the letter a, the 706 * character -, and the letter a'. 707 * 708 * For compatibility, the `-' is not considerd 709 * to define a range if the character following 710 * it is either a close bracket (required by ANSI) 711 * or is not numerically greater than the character 712 * we just stored in the table (c). 713 */ 714 n = *fmt; 715 if (n == ']' || n < c) { 716 c = '-'; 717 break; /* resume the for(;;) */ 718 } 719 fmt++; 720 do { /* fill in the range */ 721 tab[++c] = v; 722 } while (c < n); 723 #if 1 /* XXX another disgusting compatibility hack */ 724 /* 725 * Alas, the V7 Unix scanf also treats formats 726 * such as [a-c-e] as `the letters a through e'. 727 * This too is permitted by the standard.... 728 */ 729 goto doswitch; 730 #else 731 c = *fmt++; 732 if (c == 0) 733 return (fmt - 1); 734 if (c == ']') 735 return (fmt); 736 #endif 737 break; 738 739 case ']': /* end of scanset */ 740 return (fmt); 741 742 default: /* just another character */ 743 c = n; 744 break; 745 } 746 } 747 /* NOTREACHED */ 748 } 749
Indexes created Wed Sep 24 15:09:51 GMT 2025