bionic/libc/stdio/vfscanf.c

   1 /*      $OpenBSD: vfscanf.c,v 1.21 2006/01/13 21:33:28 millert Exp $ */
   2 /*-
   3  * Copyright (c) 1990, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * Chris Torek.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <ctype.h>
  35 #include <inttypes.h>
  36 #include <stdarg.h>
  37 #include <stddef.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include "local.h"
  41
  42 #ifdef FLOATING_POINT
  43 #include "floatio.h"
  44 #endif
  45
  46 #define BUF             513     /* Maximum length of numeric string. */
  47
  48 /*
  49  * Flags used during conversion.
  50  */
  51 #define LONG            0x00001 /* l: long or double */
  52 #define LONGDBL         0x00002 /* L: long double; unimplemented */
  53 #define SHORT           0x00004 /* h: short */
  54 #define SHORTSHORT      0x00008 /* hh: 8 bit integer */
  55 #define LLONG           0x00010 /* ll: long long (+ deprecated q: quad) */
  56 #define POINTER         0x00020 /* p: void * (as hex) */
  57 #define SIZEINT         0x00040 /* z: (signed) size_t */
  58 #define MAXINT          0x00080 /* j: intmax_t */
  59 #define PTRINT          0x00100 /* t: ptrdiff_t */
  60 #define NOSKIP          0x00200 /* [ or c: do not skip blanks */
  61 #define SUPPRESS        0x00400 /* *: suppress assignment */
  62 #define UNSIGNED        0x00800 /* %[oupxX] conversions */
  63
  64 /*
  65  * The following are used in numeric conversions only:
  66  * SIGNOK, HAVESIGN, NDIGITS, DPTOK, and EXPOK are for floating point;
  67  * SIGNOK, HAVESIGN, NDIGITS, PFXOK, and NZDIGITS are for integral.
  68  */
  69 #define SIGNOK          0x01000 /* +/- is (still) legal */
  70 #define HAVESIGN        0x02000 /* sign detected */
  71 #define NDIGITS         0x04000 /* no digits detected */
  72
  73 #define DPTOK           0x08000 /* (float) decimal point is still legal */
  74 #define EXPOK           0x10000 /* (float) exponent (e+3, etc) still legal */
  75
  76 #define PFXOK           0x08000 /* 0x prefix is (still) legal */
  77 #define NZDIGITS        0x10000 /* no zero digits detected */
  78
  79 /*
  80  * Conversion types.
  81  */
  82 #define CT_CHAR         0       /* %c conversion */
  83 #define CT_CCL          1       /* %[...] conversion */
  84 #define CT_STRING       2       /* %s conversion */
  85 #define CT_INT          3       /* integer, i.e., strtoimax or strtoumax */
  86 #define CT_FLOAT        4       /* floating, i.e., strtod */
  87
  88 #define u_char unsigned char
  89 #define u_long unsigned long
  90
  91 static u_char *__sccl(char *, u_char *);
  92
  93 #if !defined(VFSCANF)
  94 #define VFSCANF vfscanf
  95 #endif
  96
  97 /*
  98  * vfscanf
  99  */
 100 int
 101 VFSCANF(FILE *fp, const char *fmt0, __va_list ap)
 102 {
 103         u_char *fmt = (u_char *)fmt0;
 104         int c;          /* character from format, or conversion */
 105         size_t width;   /* field width, or 0 */
 106         char *p;        /* points into all kinds of strings */
 107         int n;          /* handy integer */
 108         int flags;      /* flags as defined above */
 109         char *p0;       /* saves original value of p when necessary */
 110         int nassigned;          /* number of fields assigned */
 111         int nread;              /* number of characters consumed from fp */
 112         int base;               /* base argument to strtoimax/strtouimax */
 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         _SET_ORIENTATION(fp, -1);
 121
 122         nassigned = 0;
 123         nread = 0;
 124         base = 0;               /* XXX just to keep gcc happy */
 125         for (;;) {
 126                 c = *fmt++;
 127                 if (c == 0)
 128                         return (nassigned);
 129                 if (isspace(c)) {
 130                         while ((fp->_r > 0 || __srefill(fp) == 0) &&
 131                             isspace(*fp->_p))
 132                                 nread++, fp->_r--, fp->_p++;
 133                         continue;
 134                 }
 135                 if (c != '%')
 136                         goto literal;
 137                 width = 0;
 138                 flags = 0;
 139                 /*
 140                  * switch on the format.  continue if done;
 141                  * break once format type is derived.
 142                  */
 143 again:          c = *fmt++;
 144                 switch (c) {
 145                 case '%':
 146 literal:
 147                         if (fp->_r <= 0 && __srefill(fp))
 148                                 goto input_failure;
 149                         if (*fp->_p != c)
 150                                 goto match_failure;
 151                         fp->_r--, fp->_p++;
 152                         nread++;
 153                         continue;
 154
 155                 case '*':
 156                         flags |= SUPPRESS;
 157                         goto again;
 158                 case 'j':
 159                         flags |= MAXINT;
 160                         goto again;
 161                 case 'L':
 162                         flags |= LONGDBL;
 163                         goto again;
 164                 case 'h':
 165                         if (*fmt == 'h') {
 166                                 fmt++;
 167                                 flags |= SHORTSHORT;
 168                         } else {
 169                                 flags |= SHORT;
 170                         }
 171                         goto again;
 172                 case 'l':
 173                         if (*fmt == 'l') {
 174                                 fmt++;
 175                                 flags |= LLONG;
 176                         } else {
 177                                 flags |= LONG;
 178                         }
 179                         goto again;
 180                 case 'q':
 181                         flags |= LLONG;         /* deprecated */
 182                         goto again;
 183                 case 't':
 184                         flags |= PTRINT;
 185                         goto again;
 186                 case 'z':
 187                         flags |= SIZEINT;
 188                         goto again;
 189
 190                 case '0': case '1': case '2': case '3': case '4':
 191                 case '5': case '6': case '7': case '8': case '9':
 192                         width = width * 10 + c - '0';
 193                         goto again;
 194
 195                 /*
 196                  * Conversions.
 197                  * Those marked `compat' are for 4.[123]BSD compatibility.
 198                  *
 199                  * (According to ANSI, E and X formats are supposed
 200                  * to the same as e and x.  Sorry about that.)
 201                  */
 202                 case 'D':       /* compat */
 203                         flags |= LONG;
 204                         /* FALLTHROUGH */
 205                 case 'd':
 206                         c = CT_INT;
 207                         base = 10;
 208                         break;
 209
 210                 case 'i':
 211                         c = CT_INT;
 212                         base = 0;
 213                         break;
 214
 215                 case 'O':       /* compat */
 216                         flags |= LONG;
 217                         /* FALLTHROUGH */
 218                 case 'o':
 219                         c = CT_INT;
 220                         flags |= UNSIGNED;
 221                         base = 8;
 222                         break;
 223
 224                 case 'u':
 225                         c = CT_INT;
 226                         flags |= UNSIGNED;
 227                         base = 10;
 228                         break;
 229
 230                 case 'X':
 231                 case 'x':
 232                         flags |= PFXOK; /* enable 0x prefixing */
 233                         c = CT_INT;
 234                         flags |= UNSIGNED;
 235                         base = 16;
 236                         break;
 237
 238 #ifdef FLOATING_POINT
 239                 case 'E':
 240                 case 'G':
 241                 case 'e':
 242                 case 'f':
 243                 case 'g':
 244                         c = CT_FLOAT;
 245                         break;
 246 #endif
 247
 248                 case 's':
 249                         c = CT_STRING;
 250                         break;
 251
 252                 case '[':
 253                         fmt = __sccl(ccltab, fmt);
 254                         flags |= NOSKIP;
 255                         c = CT_CCL;
 256                         break;
 257
 258                 case 'c':
 259                         flags |= NOSKIP;
 260                         c = CT_CHAR;
 261                         break;
 262
 263                 case 'p':       /* pointer format is like hex */
 264                         flags |= POINTER | PFXOK;
 265                         c = CT_INT;
 266                         flags |= UNSIGNED;
 267                         base = 16;
 268                         break;
 269
 270                 case 'n':
 271                         if (flags & SUPPRESS)
 272                                 continue;
 273                         if (flags & SHORTSHORT)
 274                                 *va_arg(ap, __signed char *) = nread;
 275                         else if (flags & SHORT)
 276                                 *va_arg(ap, short *) = nread;
 277                         else if (flags & LONG)
 278                                 *va_arg(ap, long *) = nread;
 279                         else if (flags & SIZEINT)
 280                                 *va_arg(ap, ssize_t *) = nread;
 281                         else if (flags & PTRINT)
 282                                 *va_arg(ap, ptrdiff_t *) = nread;
 283                         else if (flags & LLONG)
 284                                 *va_arg(ap, long long *) = nread;
 285                         else if (flags & MAXINT)
 286                                 *va_arg(ap, intmax_t *) = nread;
 287                         else
 288                                 *va_arg(ap, int *) = nread;
 289                         continue;
 290
 291                 /*
 292                  * Disgusting backwards compatibility hacks.    XXX
 293                  */
 294                 case '\0':      /* compat */
 295                         return (EOF);
 296
 297                 default:        /* compat */
 298                         if (isupper(c))
 299                                 flags |= LONG;
 300                         c = CT_INT;
 301                         base = 10;
 302                         break;
 303                 }
 304
 305                 /*
 306                  * We have a conversion that requires input.
 307                  */
 308                 if (fp->_r <= 0 && __srefill(fp))
 309                         goto input_failure;
 310
 311                 /*
 312                  * Consume leading white space, except for formats
 313                  * that suppress this.
 314                  */
 315                 if ((flags & NOSKIP) == 0) {
 316                         while (isspace(*fp->_p)) {
 317                                 nread++;
 318                                 if (--fp->_r > 0)
 319                                         fp->_p++;
 320                                 else if (__srefill(fp))
 321                                         goto input_failure;
 322                         }
 323                         /*
 324                          * Note that there is at least one character in
 325                          * the buffer, so conversions that do not set NOSKIP
 326                          * ca no longer result in an input failure.
 327                          */
 328                 }
 329
 330                 /*
 331                  * Do the conversion.
 332                  */
 333                 switch (c) {
 334
 335                 case CT_CHAR:
 336                         /* scan arbitrary characters (sets NOSKIP) */
 337                         if (width == 0)
 338                                 width = 1;
 339                         if (flags & SUPPRESS) {
 340                                 size_t sum = 0;
 341                                 for (;;) {
 342                                         if ((n = fp->_r) < (int)width) {
 343                                                 sum += n;
 344                                                 width -= n;
 345                                                 fp->_p += n;
 346                                                 if (__srefill(fp)) {
 347                                                         if (sum == 0)
 348                                                             goto input_failure;
 349                                                         break;
 350                                                 }
 351                                         } else {
 352                                                 sum += width;
 353                                                 fp->_r -= width;
 354                                                 fp->_p += width;
 355                                                 break;
 356                                         }
 357                                 }
 358                                 nread += sum;
 359                         } else {
 360                                 size_t r = fread((void *)va_arg(ap, char *), 1,
 361                                     width, fp);
 362
 363                                 if (r == 0)
 364                                         goto input_failure;
 365                                 nread += r;
 366                                 nassigned++;
 367                         }
 368                         break;
 369
 370                 case CT_CCL:
 371                         /* scan a (nonempty) character class (sets NOSKIP) */
 372                         if (width == 0)
 373                                 width = (size_t)~0;     /* `infinity' */
 374                         /* take only those things in the class */
 375                         if (flags & SUPPRESS) {
 376                                 n = 0;
 377                                 while (ccltab[*fp->_p]) {
 378                                         n++, fp->_r--, fp->_p++;
 379                                         if (--width == 0)
 380                                                 break;
 381                                         if (fp->_r <= 0 && __srefill(fp)) {
 382                                                 if (n == 0)
 383                                                         goto input_failure;
 384                                                 break;
 385                                         }
 386                                 }
 387                                 if (n == 0)
 388                                         goto match_failure;
 389                         } else {
 390                                 p0 = p = va_arg(ap, char *);
 391                                 while (ccltab[*fp->_p]) {
 392                                         fp->_r--;
 393                                         *p++ = *fp->_p++;
 394                                         if (--width == 0)
 395                                                 break;
 396                                         if (fp->_r <= 0 && __srefill(fp)) {
 397                                                 if (p == p0)
 398                                                         goto input_failure;
 399                                                 break;
 400                                         }
 401                                 }
 402                                 n = p - p0;
 403                                 if (n == 0)
 404                                         goto match_failure;
 405                                 *p = '\0';
 406                                 nassigned++;
 407                         }
 408                         nread += n;
 409                         break;
 410
 411                 case CT_STRING:
 412                         /* like CCL, but zero-length string OK, & no NOSKIP */
 413                         if (width == 0)
 414                                 width = (size_t)~0;
 415                         if (flags & SUPPRESS) {
 416                                 n = 0;
 417                                 while (!isspace(*fp->_p)) {
 418                                         n++, fp->_r--, fp->_p++;
 419                                         if (--width == 0)
 420                                                 break;
 421                                         if (fp->_r <= 0 && __srefill(fp))
 422                                                 break;
 423                                 }
 424                                 nread += n;
 425                         } else {
 426                                 p0 = p = va_arg(ap, char *);
 427                                 while (!isspace(*fp->_p)) {
 428                                         fp->_r--;
 429                                         *p++ = *fp->_p++;
 430                                         if (--width == 0)
 431                                                 break;
 432                                         if (fp->_r <= 0 && __srefill(fp))
 433                                                 break;
 434                                 }
 435                                 *p = '\0';
 436                                 nread += p - p0;
 437                                 nassigned++;
 438                         }
 439                         continue;
 440
 441                 case CT_INT:
 442                         /* scan an integer as if by strtoimax/strtoumax */
 443 #ifdef hardway
 444                         if (width == 0 || width > sizeof(buf) - 1)
 445                                 width = sizeof(buf) - 1;
 446 #else
 447                         /* size_t is unsigned, hence this optimisation */
 448                         if (--width > sizeof(buf) - 2)
 449                                 width = sizeof(buf) - 2;
 450                         width++;
 451 #endif
 452                         flags |= SIGNOK | NDIGITS | NZDIGITS;
 453                         for (p = buf; width; width--) {
 454                                 c = *fp->_p;
 455                                 /*
 456                                  * Switch on the character; `goto ok'
 457                                  * if we accept it as a part of number.
 458                                  */
 459                                 switch (c) {
 460
 461                                 /*
 462                                  * The digit 0 is always legal, but is
 463                                  * special.  For %i conversions, if no
 464                                  * digits (zero or nonzero) have been
 465                                  * scanned (only signs), we will have
 466                                  * base==0.  In that case, we should set
 467                                  * it to 8 and enable 0x prefixing.
 468                                  * Also, if we have not scanned zero digits
 469                                  * before this, do not turn off prefixing
 470                                  * (someone else will turn it off if we
 471                                  * have scanned any nonzero digits).
 472                                  */
 473                                 case '0':
 474                                         if (base == 0) {
 475                                                 base = 8;
 476                                                 flags |= PFXOK;
 477                                         }
 478                                         if (flags & NZDIGITS)
 479                                             flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
 480                                         else
 481                                             flags &= ~(SIGNOK|PFXOK|NDIGITS);
 482                                         goto ok;
 483
 484                                 /* 1 through 7 always legal */
 485                                 case '1': case '2': case '3':
 486                                 case '4': case '5': case '6': case '7':
 487                                         base = basefix[base];
 488                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 489                                         goto ok;
 490
 491                                 /* digits 8 and 9 ok iff decimal or hex */
 492                                 case '8': case '9':
 493                                         base = basefix[base];
 494                                         if (base <= 8)
 495                                                 break;  /* not legal here */
 496                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 497                                         goto ok;
 498
 499                                 /* letters ok iff hex */
 500                                 case 'A': case 'B': case 'C':
 501                                 case 'D': case 'E': case 'F':
 502                                 case 'a': case 'b': case 'c':
 503                                 case 'd': case 'e': case 'f':
 504                                         /* no need to fix base here */
 505                                         if (base <= 10)
 506                                                 break;  /* not legal here */
 507                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 508                                         goto ok;
 509
 510                                 /* sign ok only as first character */
 511                                 case '+': case '-':
 512                                         if (flags & SIGNOK) {
 513                                                 flags &= ~SIGNOK;
 514                                                 flags |= HAVESIGN;
 515                                                 goto ok;
 516                                         }
 517                                         break;
 518
 519                                 /*
 520                                  * x ok iff flag still set and 2nd char (or
 521                                  * 3rd char if we have a sign).
 522                                  */
 523                                 case 'x': case 'X':
 524                                         if ((flags & PFXOK) && p ==
 525                                             buf + 1 + !!(flags & HAVESIGN)) {
 526                                                 base = 16;      /* if %i */
 527                                                 flags &= ~PFXOK;
 528                                                 goto ok;
 529                                         }
 530                                         break;
 531                                 }
 532
 533                                 /*
 534                                  * If we got here, c is not a legal character
 535                                  * for a number.  Stop accumulating digits.
 536                                  */
 537                                 break;
 538                 ok:
 539                                 /*
 540                                  * c is legal: store it and look at the next.
 541                                  */
 542                                 *p++ = c;
 543                                 if (--fp->_r > 0)
 544                                         fp->_p++;
 545                                 else if (__srefill(fp))
 546                                         break;          /* EOF */
 547                         }
 548                         /*
 549                          * If we had only a sign, it is no good; push
 550                          * back the sign.  If the number ends in `x',
 551                          * it was [sign] '0' 'x', so push back the x
 552                          * and treat it as [sign] '0'.
 553                          */
 554                         if (flags & NDIGITS) {
 555                                 if (p > buf)
 556                                         (void) ungetc(*(u_char *)--p, fp);
 557                                 goto match_failure;
 558                         }
 559                         c = ((u_char *)p)[-1];
 560                         if (c == 'x' || c == 'X') {
 561                                 --p;
 562                                 (void) ungetc(c, fp);
 563                         }
 564                         if ((flags & SUPPRESS) == 0) {
 565                                 uintmax_t res;
 566
 567                                 *p = '\0';
 568                                 if (flags & UNSIGNED)
 569                                         res = strtoumax(buf, NULL, base);
 570                                 else
 571                                         res = strtoimax(buf, NULL, base);
 572                                 if (flags & POINTER)
 573                                         *va_arg(ap, void **) =
 574                                             (void *)(uintptr_t)res;
 575                                 else if (flags & MAXINT)
 576                                         *va_arg(ap, intmax_t *) = res;
 577                                 else if (flags & LLONG)
 578                                         *va_arg(ap, long long *) = res;
 579                                 else if (flags & SIZEINT)
 580                                         *va_arg(ap, ssize_t *) = res;
 581                                 else if (flags & PTRINT)
 582                                         *va_arg(ap, ptrdiff_t *) = res;
 583                                 else if (flags & LONG)
 584                                         *va_arg(ap, long *) = res;
 585                                 else if (flags & SHORT)
 586                                         *va_arg(ap, short *) = res;
 587                                 else if (flags & SHORTSHORT)
 588                                         *va_arg(ap, __signed char *) = res;
 589                                 else
 590                                         *va_arg(ap, int *) = res;
 591                                 nassigned++;
 592                         }
 593                         nread += p - buf;
 594                         break;
 595
 596 #ifdef FLOATING_POINT
 597                 case CT_FLOAT:
 598                         /* scan a floating point number as if by strtod */
 599 #ifdef hardway
 600                         if (width == 0 || width > sizeof(buf) - 1)
 601                                 width = sizeof(buf) - 1;
 602 #else
 603                         /* size_t is unsigned, hence this optimisation */
 604                         if (--width > sizeof(buf) - 2)
 605                                 width = sizeof(buf) - 2;
 606                         width++;
 607 #endif
 608                         flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
 609                         for (p = buf; width; width--) {
 610                                 c = *fp->_p;
 611                                 /*
 612                                  * This code mimicks the integer conversion
 613                                  * code, but is much simpler.
 614                                  */
 615                                 switch (c) {
 616
 617                                 case '0': case '1': case '2': case '3':
 618                                 case '4': case '5': case '6': case '7':
 619                                 case '8': case '9':
 620                                         flags &= ~(SIGNOK | NDIGITS);
 621                                         goto fok;
 622
 623                                 case '+': case '-':
 624                                         if (flags & SIGNOK) {
 625                                                 flags &= ~SIGNOK;
 626                                                 goto fok;
 627                                         }
 628                                         break;
 629                                 case '.':
 630                                         if (flags & DPTOK) {
 631                                                 flags &= ~(SIGNOK | DPTOK);
 632                                                 goto fok;
 633                                         }
 634                                         break;
 635                                 case 'e': case 'E':
 636                                         /* no exponent without some digits */
 637                                         if ((flags&(NDIGITS|EXPOK)) == EXPOK) {
 638                                                 flags =
 639                                                     (flags & ~(EXPOK|DPTOK)) |
 640                                                     SIGNOK | NDIGITS;
 641                                                 goto fok;
 642                                         }
 643                                         break;
 644                                 }
 645                                 break;
 646                 fok:
 647                                 *p++ = c;
 648                                 if (--fp->_r > 0)
 649                                         fp->_p++;
 650                                 else if (__srefill(fp))
 651                                         break;  /* EOF */
 652                         }
 653                         /*
 654                          * If no digits, might be missing exponent digits
 655                          * (just give back the exponent) or might be missing
 656                          * regular digits, but had sign and/or decimal point.
 657                          */
 658                         if (flags & NDIGITS) {
 659                                 if (flags & EXPOK) {
 660                                         /* no digits at all */
 661                                         while (p > buf)
 662                                                 ungetc(*(u_char *)--p, fp);
 663                                         goto match_failure;
 664                                 }
 665                                 /* just a bad exponent (e and maybe sign) */
 666                                 c = *(u_char *)--p;
 667                                 if (c != 'e' && c != 'E') {
 668                                         (void) ungetc(c, fp);/* sign */
 669                                         c = *(u_char *)--p;
 670                                 }
 671                                 (void) ungetc(c, fp);
 672                         }
 673                         if ((flags & SUPPRESS) == 0) {
 674                                 double res;
 675
 676                                 *p = '\0';
 677                                 res = strtod(buf, (char **) NULL);
 678                                 if (flags & LONGDBL)
 679                                         *va_arg(ap, long double *) = res;
 680                                 else if (flags & LONG)
 681                                         *va_arg(ap, double *) = res;
 682                                 else
 683                                         *va_arg(ap, float *) = res;
 684                                 nassigned++;
 685                         }
 686                         nread += p - buf;
 687                         break;
 688 #endif /* FLOATING_POINT */
 689                 }
 690         }
 691 input_failure:
 692         return (nassigned ? nassigned : -1);
 693 match_failure:
 694         return (nassigned);
 695 }
 696
 697 /*
 698  * Fill in the given table from the scanset at the given format
 699  * (just after `[').  Return a pointer to the character past the
 700  * closing `]'.  The table has a 1 wherever characters should be
 701  * considered part of the scanset.
 702  */
 703 static u_char *
 704 __sccl(char *tab, u_char *fmt)
 705 {
 706         int c, n, v;
 707
 708         /* first `clear' the whole table */
 709         c = *fmt++;             /* first char hat => negated scanset */
 710         if (c == '^') {
 711                 v = 1;          /* default => accept */
 712                 c = *fmt++;     /* get new first char */
 713         } else
 714                 v = 0;          /* default => reject */
 715         /* should probably use memset here */
 716         for (n = 0; n < 256; n++)
 717                 tab[n] = v;
 718         if (c == 0)
 719                 return (fmt - 1);/* format ended before closing ] */
 720
 721         /*
 722          * Now set the entries corresponding to the actual scanset
 723          * to the opposite of the above.
 724          *
 725          * The first character may be ']' (or '-') without being special;
 726          * the last character may be '-'.
 727          */
 728         v = 1 - v;
 729         for (;;) {
 730                 tab[c] = v;             /* take character c */
 731 doswitch:
 732                 n = *fmt++;             /* and examine the next */
 733                 switch (n) {
 734
 735                 case 0:                 /* format ended too soon */
 736                         return (fmt - 1);
 737
 738                 case '-':
 739                         /*
 740                          * A scanset of the form
 741                          *      [01+-]
 742                          * is defined as `the digit 0, the digit 1,
 743                          * the character +, the character -', but
 744                          * the effect of a scanset such as
 745                          *      [a-zA-Z0-9]
 746                          * is implementation defined.  The V7 Unix
 747                          * scanf treats `a-z' as `the letters a through
 748                          * z', but treats `a-a' as `the letter a, the
 749                          * character -, and the letter a'.
 750                          *
 751                          * For compatibility, the `-' is not considerd
 752                          * to define a range if the character following
 753                          * it is either a close bracket (required by ANSI)
 754                          * or is not numerically greater than the character
 755                          * we just stored in the table (c).
 756                          */
 757                         n = *fmt;
 758                         if (n == ']' || n < c) {
 759                                 c = '-';
 760                                 break;  /* resume the for(;;) */
 761                         }
 762                         fmt++;
 763                         do {            /* fill in the range */
 764                                 tab[++c] = v;
 765                         } while (c < n);
 766 #if 1   /* XXX another disgusting compatibility hack */
 767                         /*
 768                          * Alas, the V7 Unix scanf also treats formats
 769                          * such as [a-c-e] as `the letters a through e'.
 770                          * This too is permitted by the standard....
 771                          */
 772                         goto doswitch;
 773 #else
 774                         c = *fmt++;
 775                         if (c == 0)
 776                                 return (fmt - 1);
 777                         if (c == ']')
 778                                 return (fmt);
 779 #endif
 780                         break;
 781
 782                 case ']':               /* end of scanset */
 783                         return (fmt);
 784
 785                 default:                /* just another character */
 786                         c = n;
 787                         break;
 788                 }
 789         }
 790         /* NOTREACHED */
 791 }