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 * %sccs.include.redist.c% 9 */ 10 11 #if defined(LIBC_SCCS) && !defined(lint) 12 static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 06/04/93"; 13 #endif /* LIBC_SCCS and not lint */ 14 15 #include <stdio.h> 16 #include <stdlib.h> 17 #include <ctype.h> 18 #if __STDC__ 19 #include <stdarg.h> 20 #else 21 #include <varargs.h> 22 #endif 23 #include "local.h" 24 25 #define FLOATING_POINT 26 27 #include "floatio.h" 28 #define BUF 513 /* Maximum length of numeric string. */ 29 30 /* 31 * Flags used during conversion. 32 */ 33 #define LONG 0x01 /* l: long or double */ 34 #define LONGDBL 0x02 /* L: long double; unimplemented */ 35 #define SHORT 0x04 /* h: short */ 36 #define SUPPRESS 0x08 /* suppress assignment */ 37 #define POINTER 0x10 /* weird %p pointer (`fake hex') */ 38 #define NOSKIP 0x20 /* do not skip blanks */ 39 40 /* 41 * The following are used in numeric conversions only: 42 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; 43 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. 44 */ 45 #define SIGNOK 0x40 /* +/- is (still) legal */ 46 #define NDIGITS 0x80 /* no digits detected */ 47 48 #define DPTOK 0x100 /* (float) decimal point is still legal */ 49 #define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */ 50 51 #define PFXOK 0x100 /* 0x prefix is (still) legal */ 52 #define NZDIGITS 0x200 /* no zero digits detected */ 53 54 /* 55 * Conversion types. 56 */ 57 #define CT_CHAR 0 /* %c conversion */ 58 #define CT_CCL 1 /* %[...] conversion */ 59 #define CT_STRING 2 /* %s conversion */ 60 #define CT_INT 3 /* integer, i.e., strtol or strtoul */ 61 #define CT_FLOAT 4 /* floating, i.e., strtod */ 62 63 #define u_char unsigned char 64 #define u_long unsigned long 65 66 static u_char *__sccl(); 67 68 /* 69 * vfscanf 70 */ 71 __svfscanf(fp, fmt0, ap) 72 register FILE *fp; 73 char const *fmt0; 74 va_list ap; 75 { 76 register u_char *fmt = (u_char *)fmt0; 77 register int c; /* character from format, or conversion */ 78 register size_t width; /* field width, or 0 */ 79 register char *p; /* points into all kinds of strings */ 80 register int n; /* handy integer */ 81 register int flags; /* flags as defined above */ 82 register char *p0; /* saves original value of p when necessary */ 83 int nassigned; /* number of fields assigned */ 84 int nread; /* number of characters consumed from fp */ 85 int base; /* base argument to strtol/strtoul */ 86 u_long (*ccfn)(); /* conversion function (strtol/strtoul) */ 87 char ccltab[256]; /* character class table for %[...] */ 88 char buf[BUF]; /* buffer for numeric conversions */ 89 90 /* `basefix' is used to avoid `if' tests in the integer scanner */ 91 static short basefix[17] = 92 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 93 94 nassigned = 0; 95 nread = 0; 96 base = 0; /* XXX just to keep gcc happy */ 97 ccfn = NULL; /* XXX just to keep gcc happy */ 98 for (;;) { 99 c = *fmt++; 100 if (c == 0) 101 return (nassigned); 102 if (isspace(c)) { 103 for (;;) { 104 if (fp->_r <= 0 && __srefill(fp)) 105 return (nassigned); 106 if (!isspace(*fp->_p)) 107 break; 108 nread++, fp->_r--, fp->_p++; 109 } 110 continue; 111 } 112 if (c != '%') 113 goto literal; 114 width = 0; 115 flags = 0; 116 /* 117 * switch on the format. continue if done; 118 * break once format type is derived. 119 */ 120 again: c = *fmt++; 121 switch (c) { 122 case '%': 123 literal: 124 if (fp->_r <= 0 && __srefill(fp)) 125 goto input_failure; 126 if (*fp->_p != c) 127 goto match_failure; 128 fp->_r--, fp->_p++; 129 nread++; 130 continue; 131 132 case '*': 133 flags |= SUPPRESS; 134 goto again; 135 case 'l': 136 flags |= LONG; 137 goto again; 138 case 'L': 139 flags |= LONGDBL; 140 goto again; 141 case 'h': 142 flags |= SHORT; 143 goto again; 144 145 case '0': case '1': case '2': case '3': case '4': 146 case '5': case '6': case '7': case '8': case '9': 147 width = width * 10 + c - '0'; 148 goto again; 149 150 /* 151 * Conversions. 152 * Those marked `compat' are for 4.[123]BSD compatibility. 153 * 154 * (According to ANSI, E and X formats are supposed 155 * to the same as e and x. Sorry about that.) 156 */ 157 case 'D': /* compat */ 158 flags |= LONG; 159 /* FALLTHROUGH */ 160 case 'd': 161 c = CT_INT; 162 ccfn = (u_long (*)())strtol; 163 base = 10; 164 break; 165 166 case 'i': 167 c = CT_INT; 168 ccfn = (u_long (*)())strtol; 169 base = 0; 170 break; 171 172 case 'O': /* compat */ 173 flags |= LONG; 174 /* FALLTHROUGH */ 175 case 'o': 176 c = CT_INT; 177 ccfn = strtoul; 178 base = 8; 179 break; 180 181 case 'u': 182 c = CT_INT; 183 ccfn = strtoul; 184 base = 10; 185 break; 186 187 case 'X': /* compat XXX */ 188 flags |= LONG; 189 /* FALLTHROUGH */ 190 case 'x': 191 flags |= PFXOK; /* enable 0x prefixing */ 192 c = CT_INT; 193 ccfn = strtoul; 194 base = 16; 195 break; 196 197 #ifdef FLOATING_POINT 198 case 'E': /* compat XXX */ 199 case 'F': /* compat */ 200 flags |= LONG; 201 /* FALLTHROUGH */ 202 case 'e': case 'f': case 'g': 203 c = CT_FLOAT; 204 break; 205 #endif 206 207 case 's': 208 c = CT_STRING; 209 break; 210 211 case '[': 212 fmt = __sccl(ccltab, fmt); 213 flags |= NOSKIP; 214 c = CT_CCL; 215 break; 216 217 case 'c': 218 flags |= NOSKIP; 219 c = CT_CHAR; 220 break; 221 222 case 'p': /* pointer format is like hex */ 223 flags |= POINTER | PFXOK; 224 c = CT_INT; 225 ccfn = strtoul; 226 base = 16; 227 break; 228 229 case 'n': 230 if (flags & SUPPRESS) /* ??? */ 231 continue; 232 if (flags & SHORT) 233 *va_arg(ap, short *) = nread; 234 else if (flags & LONG) 235 *va_arg(ap, long *) = nread; 236 else 237 *va_arg(ap, int *) = nread; 238 continue; 239 240 /* 241 * Disgusting backwards compatibility hacks. XXX 242 */ 243 case '\0': /* compat */ 244 return (EOF); 245 246 default: /* compat */ 247 if (isupper(c)) 248 flags |= LONG; 249 c = CT_INT; 250 ccfn = (u_long (*)())strtol; 251 base = 10; 252 break; 253 } 254 255 /* 256 * We have a conversion that requires input. 257 */ 258 if (fp->_r <= 0 && __srefill(fp)) 259 goto input_failure; 260 261 /* 262 * Consume leading white space, except for formats 263 * that suppress this. 264 */ 265 if ((flags & NOSKIP) == 0) { 266 while (isspace(*fp->_p)) { 267 nread++; 268 if (--fp->_r > 0) 269 fp->_p++; 270 else if (__srefill(fp)) 271 goto input_failure; 272 } 273 /* 274 * Note that there is at least one character in 275 * the buffer, so conversions that do not set NOSKIP 276 * ca no longer result in an input failure. 277 */ 278 } 279 280 /* 281 * Do the conversion. 282 */ 283 switch (c) { 284 285 case CT_CHAR: 286 /* scan arbitrary characters (sets NOSKIP) */ 287 if (width == 0) 288 width = 1; 289 if (flags & SUPPRESS) { 290 size_t sum = 0; 291 for (;;) { 292 if ((n = fp->_r) < width) { 293 sum += n; 294 width -= n; 295 fp->_p += n; 296 if (__srefill(fp)) { 297 if (sum == 0) 298 goto input_failure; 299 break; 300 } 301 } else { 302 sum += width; 303 fp->_r -= width; 304 fp->_p += width; 305 break; 306 } 307 } 308 nread += sum; 309 } else { 310 size_t r = fread((void *)va_arg(ap, char *), 1, 311 width, fp); 312 313 if (r == 0) 314 goto input_failure; 315 nread += r; 316 nassigned++; 317 } 318 break; 319 320 case CT_CCL: 321 /* scan a (nonempty) character class (sets NOSKIP) */ 322 if (width == 0) 323 width = ~0; /* `infinity' */ 324 /* take only those things in the class */ 325 if (flags & SUPPRESS) { 326 n = 0; 327 while (ccltab[*fp->_p]) { 328 n++, fp->_r--, fp->_p++; 329 if (--width == 0) 330 break; 331 if (fp->_r <= 0 && __srefill(fp)) { 332 if (n == 0) 333 goto input_failure; 334 break; 335 } 336 } 337 if (n == 0) 338 goto match_failure; 339 } else { 340 p0 = p = va_arg(ap, char *); 341 while (ccltab[*fp->_p]) { 342 fp->_r--; 343 *p++ = *fp->_p++; 344 if (--width == 0) 345 break; 346 if (fp->_r <= 0 && __srefill(fp)) { 347 if (p == p0) 348 goto input_failure; 349 break; 350 } 351 } 352 n = p - p0; 353 if (n == 0) 354 goto match_failure; 355 *p = 0; 356 nassigned++; 357 } 358 nread += n; 359 break; 360 361 case CT_STRING: 362 /* like CCL, but zero-length string OK, & no NOSKIP */ 363 if (width == 0) 364 width = ~0; 365 if (flags & SUPPRESS) { 366 n = 0; 367 while (!isspace(*fp->_p)) { 368 n++, fp->_r--, fp->_p++; 369 if (--width == 0) 370 break; 371 if (fp->_r <= 0 && __srefill(fp)) 372 break; 373 } 374 nread += n; 375 } else { 376 p0 = p = va_arg(ap, char *); 377 while (!isspace(*fp->_p)) { 378 fp->_r--; 379 *p++ = *fp->_p++; 380 if (--width == 0) 381 break; 382 if (fp->_r <= 0 && __srefill(fp)) 383 break; 384 } 385 *p = 0; 386 nread += p - p0; 387 nassigned++; 388 } 389 continue; 390 391 case CT_INT: 392 /* scan an integer as if by strtol/strtoul */ 393 #ifdef hardway 394 if (width == 0 || width > sizeof(buf) - 1) 395 width = sizeof(buf) - 1; 396 #else 397 /* size_t is unsigned, hence this optimisation */ 398 if (--width > sizeof(buf) - 2) 399 width = sizeof(buf) - 2; 400 width++; 401 #endif 402 flags |= SIGNOK | NDIGITS | NZDIGITS; 403 for (p = buf; width; width--) { 404 c = *fp->_p; 405 /* 406 * Switch on the character; `goto ok' 407 * if we accept it as a part of number. 408 */ 409 switch (c) { 410 411 /* 412 * The digit 0 is always legal, but is 413 * special. For %i conversions, if no 414 * digits (zero or nonzero) have been 415 * scanned (only signs), we will have 416 * base==0. In that case, we should set 417 * it to 8 and enable 0x prefixing. 418 * Also, if we have not scanned zero digits 419 * before this, do not turn off prefixing 420 * (someone else will turn it off if we 421 * have scanned any nonzero digits). 422 */ 423 case '0': 424 if (base == 0) { 425 base = 8; 426 flags |= PFXOK; 427 } 428 if (flags & NZDIGITS) 429 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 430 else 431 flags &= ~(SIGNOK|PFXOK|NDIGITS); 432 goto ok; 433 434 /* 1 through 7 always legal */ 435 case '1': case '2': case '3': 436 case '4': case '5': case '6': case '7': 437 base = basefix[base]; 438 flags &= ~(SIGNOK | PFXOK | NDIGITS); 439 goto ok; 440 441 /* digits 8 and 9 ok iff decimal or hex */ 442 case '8': case '9': 443 base = basefix[base]; 444 if (base <= 8) 445 break; /* not legal here */ 446 flags &= ~(SIGNOK | PFXOK | NDIGITS); 447 goto ok; 448 449 /* letters ok iff hex */ 450 case 'A': case 'B': case 'C': 451 case 'D': case 'E': case 'F': 452 case 'a': case 'b': case 'c': 453 case 'd': case 'e': case 'f': 454 /* no need to fix base here */ 455 if (base <= 10) 456 break; /* not legal here */ 457 flags &= ~(SIGNOK | PFXOK | NDIGITS); 458 goto ok; 459 460 /* sign ok only as first character */ 461 case '+': case '-': 462 if (flags & SIGNOK) { 463 flags &= ~SIGNOK; 464 goto ok; 465 } 466 break; 467 468 /* x ok iff flag still set & 2nd char */ 469 case 'x': case 'X': 470 if (flags & PFXOK && p == buf + 1) { 471 base = 16; /* if %i */ 472 flags &= ~PFXOK; 473 goto ok; 474 } 475 break; 476 } 477 478 /* 479 * If we got here, c is not a legal character 480 * for a number. Stop accumulating digits. 481 */ 482 break; 483 ok: 484 /* 485 * c is legal: store it and look at the next. 486 */ 487 *p++ = c; 488 if (--fp->_r > 0) 489 fp->_p++; 490 else if (__srefill(fp)) 491 break; /* EOF */ 492 } 493 /* 494 * If we had only a sign, it is no good; push 495 * back the sign. If the number ends in `x', 496 * it was [sign] '0' 'x', so push back the x 497 * and treat it as [sign] '0'. 498 */ 499 if (flags & NDIGITS) { 500 if (p > buf) 501 (void) ungetc(*(u_char *)--p, fp); 502 goto match_failure; 503 } 504 c = ((u_char *)p)[-1]; 505 if (c == 'x' || c == 'X') { 506 --p; 507 (void) ungetc(c, fp); 508 } 509 if ((flags & SUPPRESS) == 0) { 510 u_long res; 511 512 *p = 0; 513 res = (*ccfn)(buf, (char **)NULL, base); 514 if (flags & POINTER) 515 *va_arg(ap, void **) = (void *)res; 516 else if (flags & SHORT) 517 *va_arg(ap, short *) = res; 518 else if (flags & LONG) 519 *va_arg(ap, long *) = res; 520 else 521 *va_arg(ap, int *) = res; 522 nassigned++; 523 } 524 nread += p - buf; 525 break; 526 527 #ifdef FLOATING_POINT 528 case CT_FLOAT: 529 /* scan a floating point number as if by strtod */ 530 #ifdef hardway 531 if (width == 0 || width > sizeof(buf) - 1) 532 width = sizeof(buf) - 1; 533 #else 534 /* size_t is unsigned, hence this optimisation */ 535 if (--width > sizeof(buf) - 2) 536 width = sizeof(buf) - 2; 537 width++; 538 #endif 539 flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; 540 for (p = buf; width; width--) { 541 c = *fp->_p; 542 /* 543 * This code mimicks the integer conversion 544 * code, but is much simpler. 545 */ 546 switch (c) { 547 548 case '0': case '1': case '2': case '3': 549 case '4': case '5': case '6': case '7': 550 case '8': case '9': 551 flags &= ~(SIGNOK | NDIGITS); 552 goto fok; 553 554 case '+': case '-': 555 if (flags & SIGNOK) { 556 flags &= ~SIGNOK; 557 goto fok; 558 } 559 break; 560 case '.': 561 if (flags & DPTOK) { 562 flags &= ~(SIGNOK | DPTOK); 563 goto fok; 564 } 565 break; 566 case 'e': case 'E': 567 /* no exponent without some digits */ 568 if ((flags&(NDIGITS|EXPOK)) == EXPOK) { 569 flags = 570 (flags & ~(EXPOK|DPTOK)) | 571 SIGNOK | NDIGITS; 572 goto fok; 573 } 574 break; 575 } 576 break; 577 fok: 578 *p++ = c; 579 if (--fp->_r > 0) 580 fp->_p++; 581 else if (__srefill(fp)) 582 break; /* EOF */ 583 } 584 /* 585 * If no digits, might be missing exponent digits 586 * (just give back the exponent) or might be missing 587 * regular digits, but had sign and/or decimal point. 588 */ 589 if (flags & NDIGITS) { 590 if (flags & EXPOK) { 591 /* no digits at all */ 592 while (p > buf) 593 ungetc(*(u_char *)--p, fp); 594 goto match_failure; 595 } 596 /* just a bad exponent (e and maybe sign) */ 597 c = *(u_char *)--p; 598 if (c != 'e' && c != 'E') { 599 (void) ungetc(c, fp);/* sign */ 600 c = *(u_char *)--p; 601 } 602 (void) ungetc(c, fp); 603 } 604 if ((flags & SUPPRESS) == 0) { 605 double res; 606 607 *p = 0; 608 res = strtod(buf,(char **) NULL); 609 if (flags & LONG) 610 *va_arg(ap, double *) = res; 611 else 612 *va_arg(ap, float *) = res; 613 nassigned++; 614 } 615 nread += p - buf; 616 break; 617 #endif /* FLOATING_POINT */ 618 } 619 } 620 input_failure: 621 return (nassigned ? nassigned : -1); 622 match_failure: 623 return (nassigned); 624 } 625 626 /* 627 * Fill in the given table from the scanset at the given format 628 * (just after `['). Return a pointer to the character past the 629 * closing `]'. The table has a 1 wherever characters should be 630 * considered part of the scanset. 631 */ 632 static u_char * 633 __sccl(tab, fmt) 634 register char *tab; 635 register u_char *fmt; 636 { 637 register int c, n, v; 638 639 /* first `clear' the whole table */ 640 c = *fmt++; /* first char hat => negated scanset */ 641 if (c == '^') { 642 v = 1; /* default => accept */ 643 c = *fmt++; /* get new first char */ 644 } else 645 v = 0; /* default => reject */ 646 /* should probably use memset here */ 647 for (n = 0; n < 256; n++) 648 tab[n] = v; 649 if (c == 0) 650 return (fmt - 1);/* format ended before closing ] */ 651 652 /* 653 * Now set the entries corresponding to the actual scanset 654 * to the opposite of the above. 655 * 656 * The first character may be ']' (or '-') without being special; 657 * the last character may be '-'. 658 */ 659 v = 1 - v; 660 for (;;) { 661 tab[c] = v; /* take character c */ 662 doswitch: 663 n = *fmt++; /* and examine the next */ 664 switch (n) { 665 666 case 0: /* format ended too soon */ 667 return (fmt - 1); 668 669 case '-': 670 /* 671 * A scanset of the form 672 * [01+-] 673 * is defined as `the digit 0, the digit 1, 674 * the character +, the character -', but 675 * the effect of a scanset such as 676 * [a-zA-Z0-9] 677 * is implementation defined. The V7 Unix 678 * scanf treats `a-z' as `the letters a through 679 * z', but treats `a-a' as `the letter a, the 680 * character -, and the letter a'. 681 * 682 * For compatibility, the `-' is not considerd 683 * to define a range if the character following 684 * it is either a close bracket (required by ANSI) 685 * or is not numerically greater than the character 686 * we just stored in the table (c). 687 */ 688 n = *fmt; 689 if (n == ']' || n < c) { 690 c = '-'; 691 break; /* resume the for(;;) */ 692 } 693 fmt++; 694 do { /* fill in the range */ 695 tab[++c] = v; 696 } while (c < n); 697 #if 1 /* XXX another disgusting compatibility hack */ 698 /* 699 * Alas, the V7 Unix scanf also treats formats 700 * such as [a-c-e] as `the letters a through e'. 701 * This too is permitted by the standard.... 702 */ 703 goto doswitch; 704 #else 705 c = *fmt++; 706 if (c == 0) 707 return (fmt - 1); 708 if (c == ']') 709 return (fmt); 710 #endif 711 break; 712 713 case ']': /* end of scanset */ 714 return (fmt); 715 716 default: /* just another character */ 717 c = n; 718 break; 719 } 720 } 721 /* NOTREACHED */ 722 } 723