1 /* $NetBSD: vfscanf.c,v 1.15 1996/03/29 23:29:28 jtc 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 #if defined(LIBC_SCCS) && !defined(lint) 40 #if 0 41 static char sccsid[] = "@(#)vfscanf.c 8.1 (Berkeley) 6/4/93"; 42 #endif 43 static char rcsid[] = "$NetBSD: vfscanf.c,v 1.15 1996/03/29 23:29:28 jtc Exp $"; 44 #endif /* LIBC_SCCS and not lint */ 45 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <ctype.h> 49 #if __STDC__ 50 #include <stdarg.h> 51 #else 52 #include <varargs.h> 53 #endif 54 #include "local.h" 55 56 #ifdef FLOATING_POINT 57 #include "floatio.h" 58 #endif 59 60 #define BUF 513 /* Maximum length of numeric string. */ 61 62 /* 63 * Flags used during conversion. 64 */ 65 #define LONG 0x01 /* l: long or double */ 66 #define LONGDBL 0x02 /* L: long double; unimplemented */ 67 #define SHORT 0x04 /* h: short */ 68 #define QUAD 0x08 /* q: quad */ 69 #define SUPPRESS 0x10 /* suppress assignment */ 70 #define POINTER 0x20 /* weird %p pointer (`fake hex') */ 71 #define NOSKIP 0x40 /* do not skip blanks */ 72 73 /* 74 * The following are used in numeric conversions only: 75 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; 76 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. 77 */ 78 #define SIGNOK 0x080 /* +/- is (still) legal */ 79 #define NDIGITS 0x100 /* no digits detected */ 80 81 #define DPTOK 0x200 /* (float) decimal point is still legal */ 82 #define EXPOK 0x400 /* (float) exponent (e+3, etc) still legal */ 83 84 #define PFXOK 0x200 /* 0x prefix is (still) legal */ 85 #define NZDIGITS 0x400 /* no zero digits detected */ 86 87 /* 88 * Conversion types. 89 */ 90 #define CT_CHAR 0 /* %c conversion */ 91 #define CT_CCL 1 /* %[...] conversion */ 92 #define CT_STRING 2 /* %s conversion */ 93 #define CT_INT 3 /* integer, i.e., strtoq or strtouq */ 94 #define CT_FLOAT 4 /* floating, i.e., strtod */ 95 96 #define u_char unsigned char 97 #define u_long unsigned long 98 99 static u_char *__sccl(); 100 101 /* 102 * vfscanf 103 */ 104 int 105 __svfscanf(fp, fmt0, ap) 106 register FILE *fp; 107 char const *fmt0; 108 _BSD_VA_LIST_ ap; 109 { 110 register u_char *fmt = (u_char *)fmt0; 111 register int c; /* character from format, or conversion */ 112 register size_t width; /* field width, or 0 */ 113 register char *p; /* points into all kinds of strings */ 114 register int n; /* handy integer */ 115 register int flags; /* flags as defined above */ 116 register char *p0; /* saves original value of p when necessary */ 117 int nassigned; /* number of fields assigned */ 118 int nread; /* number of characters consumed from fp */ 119 int base; /* base argument to strtoq/strtouq */ 120 u_quad_t (*ccfn)(); /* conversion function (strtoq/strtouq) */ 121 char ccltab[256]; /* character class table for %[...] */ 122 char buf[BUF]; /* buffer for numeric conversions */ 123 124 /* `basefix' is used to avoid `if' tests in the integer scanner */ 125 static short basefix[17] = 126 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; 127 128 nassigned = 0; 129 nread = 0; 130 base = 0; /* XXX just to keep gcc happy */ 131 ccfn = NULL; /* XXX just to keep gcc happy */ 132 for (;;) { 133 c = *fmt++; 134 if (c == 0) 135 return (nassigned); 136 if (isspace(c)) { 137 for (;;) { 138 if (fp->_r <= 0 && __srefill(fp)) 139 return (nassigned); 140 if (!isspace(*fp->_p)) 141 break; 142 nread++, fp->_r--, fp->_p++; 143 } 144 continue; 145 } 146 if (c != '%') 147 goto literal; 148 width = 0; 149 flags = 0; 150 /* 151 * switch on the format. continue if done; 152 * break once format type is derived. 153 */ 154 again: c = *fmt++; 155 switch (c) { 156 case '%': 157 literal: 158 if (fp->_r <= 0 && __srefill(fp)) 159 goto input_failure; 160 if (*fp->_p != c) 161 goto match_failure; 162 fp->_r--, fp->_p++; 163 nread++; 164 continue; 165 166 case '*': 167 flags |= SUPPRESS; 168 goto again; 169 case 'L': 170 flags |= LONGDBL; 171 goto again; 172 case 'h': 173 flags |= SHORT; 174 goto again; 175 case 'l': 176 if (*fmt == 'l') { 177 fmt++; 178 flags |= QUAD; 179 } else { 180 flags |= LONG; 181 } 182 goto again; 183 case 'q': 184 flags |= QUAD; 185 goto again; 186 187 case '0': case '1': case '2': case '3': case '4': 188 case '5': case '6': case '7': case '8': case '9': 189 width = width * 10 + c - '0'; 190 goto again; 191 192 /* 193 * Conversions. 194 * Those marked `compat' are for 4.[123]BSD compatibility. 195 * 196 * (According to ANSI, E and X formats are supposed 197 * to the same as e and x. Sorry about that.) 198 */ 199 case 'D': /* compat */ 200 flags |= LONG; 201 /* FALLTHROUGH */ 202 case 'd': 203 c = CT_INT; 204 ccfn = (u_quad_t (*)())strtoq; 205 base = 10; 206 break; 207 208 case 'i': 209 c = CT_INT; 210 ccfn = (u_quad_t (*)())strtoq; 211 base = 0; 212 break; 213 214 case 'O': /* compat */ 215 flags |= LONG; 216 /* FALLTHROUGH */ 217 case 'o': 218 c = CT_INT; 219 ccfn = strtouq; 220 base = 8; 221 break; 222 223 case 'u': 224 c = CT_INT; 225 ccfn = strtouq; 226 base = 10; 227 break; 228 229 case 'X': 230 case 'x': 231 flags |= PFXOK; /* enable 0x prefixing */ 232 c = CT_INT; 233 ccfn = strtouq; 234 base = 16; 235 break; 236 237 #ifdef FLOATING_POINT 238 case 'E': 239 case 'G': 240 case 'e': 241 case 'f': 242 case 'g': 243 c = CT_FLOAT; 244 break; 245 #endif 246 247 case 's': 248 c = CT_STRING; 249 break; 250 251 case '[': 252 fmt = __sccl(ccltab, fmt); 253 flags |= NOSKIP; 254 c = CT_CCL; 255 break; 256 257 case 'c': 258 flags |= NOSKIP; 259 c = CT_CHAR; 260 break; 261 262 case 'p': /* pointer format is like hex */ 263 flags |= POINTER | PFXOK; 264 c = CT_INT; 265 ccfn = strtouq; 266 base = 16; 267 break; 268 269 case 'n': 270 if (flags & SUPPRESS) /* ??? */ 271 continue; 272 if (flags & SHORT) 273 *va_arg(ap, short *) = nread; 274 else if (flags & LONG) 275 *va_arg(ap, long *) = nread; 276 else 277 *va_arg(ap, int *) = nread; 278 continue; 279 280 /* 281 * Disgusting backwards compatibility hacks. XXX 282 */ 283 case '\0': /* compat */ 284 return (EOF); 285 286 default: /* compat */ 287 if (isupper(c)) 288 flags |= LONG; 289 c = CT_INT; 290 ccfn = (u_quad_t (*)())strtoq; 291 base = 10; 292 break; 293 } 294 295 /* 296 * We have a conversion that requires input. 297 */ 298 if (fp->_r <= 0 && __srefill(fp)) 299 goto input_failure; 300 301 /* 302 * Consume leading white space, except for formats 303 * that suppress this. 304 */ 305 if ((flags & NOSKIP) == 0) { 306 while (isspace(*fp->_p)) { 307 nread++; 308 if (--fp->_r > 0) 309 fp->_p++; 310 else if (__srefill(fp)) 311 goto input_failure; 312 } 313 /* 314 * Note that there is at least one character in 315 * the buffer, so conversions that do not set NOSKIP 316 * ca no longer result in an input failure. 317 */ 318 } 319 320 /* 321 * Do the conversion. 322 */ 323 switch (c) { 324 325 case CT_CHAR: 326 /* scan arbitrary characters (sets NOSKIP) */ 327 if (width == 0) 328 width = 1; 329 if (flags & SUPPRESS) { 330 size_t sum = 0; 331 for (;;) { 332 if ((n = fp->_r) < width) { 333 sum += n; 334 width -= n; 335 fp->_p += n; 336 if (__srefill(fp)) { 337 if (sum == 0) 338 goto input_failure; 339 break; 340 } 341 } else { 342 sum += width; 343 fp->_r -= width; 344 fp->_p += width; 345 break; 346 } 347 } 348 nread += sum; 349 } else { 350 size_t r = fread((void *)va_arg(ap, char *), 1, 351 width, fp); 352 353 if (r == 0) 354 goto input_failure; 355 nread += r; 356 nassigned++; 357 } 358 break; 359 360 case CT_CCL: 361 /* scan a (nonempty) character class (sets NOSKIP) */ 362 if (width == 0) 363 width = ~0; /* `infinity' */ 364 /* take only those things in the class */ 365 if (flags & SUPPRESS) { 366 n = 0; 367 while (ccltab[*fp->_p]) { 368 n++, fp->_r--, fp->_p++; 369 if (--width == 0) 370 break; 371 if (fp->_r <= 0 && __srefill(fp)) { 372 if (n == 0) 373 goto input_failure; 374 break; 375 } 376 } 377 if (n == 0) 378 goto match_failure; 379 } else { 380 p0 = p = va_arg(ap, char *); 381 while (ccltab[*fp->_p]) { 382 fp->_r--; 383 *p++ = *fp->_p++; 384 if (--width == 0) 385 break; 386 if (fp->_r <= 0 && __srefill(fp)) { 387 if (p == p0) 388 goto input_failure; 389 break; 390 } 391 } 392 n = p - p0; 393 if (n == 0) 394 goto match_failure; 395 *p = 0; 396 nassigned++; 397 } 398 nread += n; 399 break; 400 401 case CT_STRING: 402 /* like CCL, but zero-length string OK, & no NOSKIP */ 403 if (width == 0) 404 width = ~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 continue; 430 431 case CT_INT: 432 /* scan an integer as if by strtoq/strtouq */ 433 #ifdef hardway 434 if (width == 0 || width > sizeof(buf) - 1) 435 width = sizeof(buf) - 1; 436 #else 437 /* size_t is unsigned, hence this optimisation */ 438 if (--width > sizeof(buf) - 2) 439 width = sizeof(buf) - 2; 440 width++; 441 #endif 442 flags |= SIGNOK | NDIGITS | NZDIGITS; 443 for (p = buf; width; width--) { 444 c = *fp->_p; 445 /* 446 * Switch on the character; `goto ok' 447 * if we accept it as a part of number. 448 */ 449 switch (c) { 450 451 /* 452 * The digit 0 is always legal, but is 453 * special. For %i conversions, if no 454 * digits (zero or nonzero) have been 455 * scanned (only signs), we will have 456 * base==0. In that case, we should set 457 * it to 8 and enable 0x prefixing. 458 * Also, if we have not scanned zero digits 459 * before this, do not turn off prefixing 460 * (someone else will turn it off if we 461 * have scanned any nonzero digits). 462 */ 463 case '0': 464 if (base == 0) { 465 base = 8; 466 flags |= PFXOK; 467 } 468 if (flags & NZDIGITS) 469 flags &= ~(SIGNOK|NZDIGITS|NDIGITS); 470 else 471 flags &= ~(SIGNOK|PFXOK|NDIGITS); 472 goto ok; 473 474 /* 1 through 7 always legal */ 475 case '1': case '2': case '3': 476 case '4': case '5': case '6': case '7': 477 base = basefix[base]; 478 flags &= ~(SIGNOK | PFXOK | NDIGITS); 479 goto ok; 480 481 /* digits 8 and 9 ok iff decimal or hex */ 482 case '8': case '9': 483 base = basefix[base]; 484 if (base <= 8) 485 break; /* not legal here */ 486 flags &= ~(SIGNOK | PFXOK | NDIGITS); 487 goto ok; 488 489 /* letters ok iff hex */ 490 case 'A': case 'B': case 'C': 491 case 'D': case 'E': case 'F': 492 case 'a': case 'b': case 'c': 493 case 'd': case 'e': case 'f': 494 /* no need to fix base here */ 495 if (base <= 10) 496 break; /* not legal here */ 497 flags &= ~(SIGNOK | PFXOK | NDIGITS); 498 goto ok; 499 500 /* sign ok only as first character */ 501 case '+': case '-': 502 if (flags & SIGNOK) { 503 flags &= ~SIGNOK; 504 goto ok; 505 } 506 break; 507 508 /* x ok iff flag still set & 2nd char */ 509 case 'x': case 'X': 510 if (flags & PFXOK && p == buf + 1) { 511 base = 16; /* if %i */ 512 flags &= ~PFXOK; 513 goto ok; 514 } 515 break; 516 } 517 518 /* 519 * If we got here, c is not a legal character 520 * for a number. Stop accumulating digits. 521 */ 522 break; 523 ok: 524 /* 525 * c is legal: store it and look at the next. 526 */ 527 *p++ = c; 528 if (--fp->_r > 0) 529 fp->_p++; 530 else if (__srefill(fp)) 531 break; /* EOF */ 532 } 533 /* 534 * If we had only a sign, it is no good; push 535 * back the sign. If the number ends in `x', 536 * it was [sign] '0' 'x', so push back the x 537 * and treat it as [sign] '0'. 538 */ 539 if (flags & NDIGITS) { 540 if (p > buf) 541 (void) ungetc(*(u_char *)--p, fp); 542 goto match_failure; 543 } 544 c = ((u_char *)p)[-1]; 545 if (c == 'x' || c == 'X') { 546 --p; 547 (void) ungetc(c, fp); 548 } 549 if ((flags & SUPPRESS) == 0) { 550 u_quad_t res; 551 552 *p = 0; 553 res = (*ccfn)(buf, (char **)NULL, base); 554 if (flags & POINTER) 555 *va_arg(ap, void **) = 556 (void *)(long)res; 557 else if (flags & QUAD) 558 *va_arg(ap, quad_t *) = res; 559 else if (flags & LONG) 560 *va_arg(ap, long *) = res; 561 else if (flags & SHORT) 562 *va_arg(ap, short *) = res; 563 else 564 *va_arg(ap, int *) = res; 565 nassigned++; 566 } 567 nread += p - buf; 568 break; 569 570 #ifdef FLOATING_POINT 571 case CT_FLOAT: 572 /* scan a floating point number as if by strtod */ 573 #ifdef hardway 574 if (width == 0 || width > sizeof(buf) - 1) 575 width = sizeof(buf) - 1; 576 #else 577 /* size_t is unsigned, hence this optimisation */ 578 if (--width > sizeof(buf) - 2) 579 width = sizeof(buf) - 2; 580 width++; 581 #endif 582 flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; 583 for (p = buf; width; width--) { 584 c = *fp->_p; 585 /* 586 * This code mimicks the integer conversion 587 * code, but is much simpler. 588 */ 589 switch (c) { 590 591 case '0': case '1': case '2': case '3': 592 case '4': case '5': case '6': case '7': 593 case '8': case '9': 594 flags &= ~(SIGNOK | NDIGITS); 595 goto fok; 596 597 case '+': case '-': 598 if (flags & SIGNOK) { 599 flags &= ~SIGNOK; 600 goto fok; 601 } 602 break; 603 case '.': 604 if (flags & DPTOK) { 605 flags &= ~(SIGNOK | DPTOK); 606 goto fok; 607 } 608 break; 609 case 'e': case 'E': 610 /* no exponent without some digits */ 611 if ((flags&(NDIGITS|EXPOK)) == EXPOK) { 612 flags = 613 (flags & ~(EXPOK|DPTOK)) | 614 SIGNOK | NDIGITS; 615 goto fok; 616 } 617 break; 618 } 619 break; 620 fok: 621 *p++ = c; 622 if (--fp->_r > 0) 623 fp->_p++; 624 else if (__srefill(fp)) 625 break; /* EOF */ 626 } 627 /* 628 * If no digits, might be missing exponent digits 629 * (just give back the exponent) or might be missing 630 * regular digits, but had sign and/or decimal point. 631 */ 632 if (flags & NDIGITS) { 633 if (flags & EXPOK) { 634 /* no digits at all */ 635 while (p > buf) 636 ungetc(*(u_char *)--p, fp); 637 goto match_failure; 638 } 639 /* just a bad exponent (e and maybe sign) */ 640 c = *(u_char *)--p; 641 if (c != 'e' && c != 'E') { 642 (void) ungetc(c, fp);/* sign */ 643 c = *(u_char *)--p; 644 } 645 (void) ungetc(c, fp); 646 } 647 if ((flags & SUPPRESS) == 0) { 648 double res; 649 650 *p = 0; 651 res = strtod(buf, (char **) NULL); 652 if (flags & LONGDBL) 653 *va_arg(ap, long double *) = res; 654 else if (flags & LONG) 655 *va_arg(ap, double *) = res; 656 else 657 *va_arg(ap, float *) = res; 658 nassigned++; 659 } 660 nread += p - buf; 661 break; 662 #endif /* FLOATING_POINT */ 663 } 664 } 665 input_failure: 666 return (nassigned ? nassigned : -1); 667 match_failure: 668 return (nassigned); 669 } 670 671 /* 672 * Fill in the given table from the scanset at the given format 673 * (just after `['). Return a pointer to the character past the 674 * closing `]'. The table has a 1 wherever characters should be 675 * considered part of the scanset. 676 */ 677 static u_char * 678 __sccl(tab, fmt) 679 register char *tab; 680 register u_char *fmt; 681 { 682 register int c, n, v; 683 684 /* first `clear' the whole table */ 685 c = *fmt++; /* first char hat => negated scanset */ 686 if (c == '^') { 687 v = 1; /* default => accept */ 688 c = *fmt++; /* get new first char */ 689 } else 690 v = 0; /* default => reject */ 691 /* should probably use memset here */ 692 for (n = 0; n < 256; n++) 693 tab[n] = v; 694 if (c == 0) 695 return (fmt - 1);/* format ended before closing ] */ 696 697 /* 698 * Now set the entries corresponding to the actual scanset 699 * to the opposite of the above. 700 * 701 * The first character may be ']' (or '-') without being special; 702 * the last character may be '-'. 703 */ 704 v = 1 - v; 705 for (;;) { 706 tab[c] = v; /* take character c */ 707 doswitch: 708 n = *fmt++; /* and examine the next */ 709 switch (n) { 710 711 case 0: /* format ended too soon */ 712 return (fmt - 1); 713 714 case '-': 715 /* 716 * A scanset of the form 717 * [01+-] 718 * is defined as `the digit 0, the digit 1, 719 * the character +, the character -', but 720 * the effect of a scanset such as 721 * [a-zA-Z0-9] 722 * is implementation defined. The V7 Unix 723 * scanf treats `a-z' as `the letters a through 724 * z', but treats `a-a' as `the letter a, the 725 * character -, and the letter a'. 726 * 727 * For compatibility, the `-' is not considerd 728 * to define a range if the character following 729 * it is either a close bracket (required by ANSI) 730 * or is not numerically greater than the character 731 * we just stored in the table (c). 732 */ 733 n = *fmt; 734 if (n == ']' || n < c) { 735 c = '-'; 736 break; /* resume the for(;;) */ 737 } 738 fmt++; 739 do { /* fill in the range */ 740 tab[++c] = v; 741 } while (c < n); 742 #if 1 /* XXX another disgusting compatibility hack */ 743 /* 744 * Alas, the V7 Unix scanf also treats formats 745 * such as [a-c-e] as `the letters a through e'. 746 * This too is permitted by the standard.... 747 */ 748 goto doswitch; 749 #else 750 c = *fmt++; 751 if (c == 0) 752 return (fmt - 1); 753 if (c == ']') 754 return (fmt); 755 #endif 756 break; 757 758 case ']': /* end of scanset */ 759 return (fmt); 760 761 default: /* just another character */ 762 c = n; 763 break; 764 } 765 } 766 /* NOTREACHED */ 767 } 768