stdio/vfscanf.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1990, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * This code is derived from software contributed to Berkeley by
  27  * Chris Torek.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <ctype.h>
  62 #if __STDC__
  63 #include <stdarg.h>
  64 #else
  65 #include <varargs.h>
  66 #endif
  67 #include "local.h"
  68
  69 #define FLOATING_POINT
  70
  71 #include "floatio.h"
  72 #define BUF             513     /* Maximum length of numeric string. */
  73
  74 /*
  75  * Flags used during conversion.
  76  */
  77 #define LONG            0x01    /* l: long or double */
  78 #define LONGDBL         0x02    /* L: long double; unimplemented */
  79 #define SHORT           0x04    /* h: short */
  80 #define SUPPRESS        0x08    /* suppress assignment */
  81 #define POINTER         0x10    /* weird %p pointer (`fake hex') */
  82 #define NOSKIP          0x20    /* do not skip blanks */
  83 #define QUAD            0x400
  84
  85 /*
  86  * The following are used in numeric conversions only:
  87  * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
  88  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
  89  */
  90 #define SIGNOK          0x40    /* +/- is (still) legal */
  91 #define NDIGITS         0x80    /* no digits detected */
  92
  93 #define DPTOK           0x100   /* (float) decimal point is still legal */
  94 #define EXPOK           0x200   /* (float) exponent (e+3, etc) still legal */
  95
  96 #define PFXOK           0x100   /* 0x prefix is (still) legal */
  97 #define NZDIGITS        0x200   /* no zero digits detected */
  98
  99 /*
 100  * Conversion types.
 101  */
 102 #define CT_CHAR         0       /* %c conversion */
 103 #define CT_CCL          1       /* %[...] conversion */
 104 #define CT_STRING       2       /* %s conversion */
 105 #define CT_INT          3       /* integer, i.e., strtoq or strtouq */
 106 #define CT_FLOAT        4       /* floating, i.e., strtod */
 107
 108 #define u_char unsigned char
 109 #define u_long unsigned long
 110
 111 static u_char *__sccl(char *, u_char *);
 112
 113 /*
 114  * vfscanf
 115  */
 116 int
 117 __svfscanf(fp, fmt0, ap)
 118         register FILE *fp;
 119         char const *fmt0;
 120         va_list ap;
 121 {
 122         register u_char *fmt = (u_char *)fmt0;
 123         register int c;         /* character from format, or conversion */
 124         register size_t width;  /* field width, or 0 */
 125         register char *p;       /* points into all kinds of strings */
 126         register int n;         /* handy integer */
 127         register int flags;     /* flags as defined above */
 128         register char *p0;      /* saves original value of p when necessary */
 129         int nassigned;          /* number of fields assigned */
 130         int nread;              /* number of characters consumed from fp */
 131         int base;               /* base argument to strtoq/strtouq */
 132         u_quad_t (*ccfn)();     /* conversion function (strtoq/strtouq) */
 133         char ccltab[256];       /* character class table for %[...] */
 134         char buf[BUF];          /* buffer for numeric conversions */
 135
 136         /* `basefix' is used to avoid `if' tests in the integer scanner */
 137         static short basefix[17] =
 138                 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
 139
 140         nassigned = 0;
 141         nread = 0;
 142         base = 0;               /* XXX just to keep gcc happy */
 143         ccfn = NULL;            /* XXX just to keep gcc happy */
 144         for (;;) {
 145                 c = *fmt++;
 146                 if (c == 0)
 147                         return (nassigned);
 148                 if (isspace(c)) {
 149                         for (;;) {
 150                                 if (fp->_r <= 0 && __srefill(fp))
 151                                         return (nassigned);
 152                                 if (!isspace(*fp->_p))
 153                                         break;
 154                                 nread++, fp->_r--, fp->_p++;
 155                         }
 156                         continue;
 157                 }
 158                 if (c != '%')
 159                         goto literal;
 160                 width = 0;
 161                 flags = 0;
 162                 /*
 163                  * switch on the format.  continue if done;
 164                  * break once format type is derived.
 165                  */
 166 again:          c = *fmt++;
 167                 switch (c) {
 168                 case '%':
 169 literal:
 170                         if (fp->_r <= 0 && __srefill(fp))
 171                                 goto input_failure;
 172                         if (*fp->_p != c)
 173                                 goto match_failure;
 174                         fp->_r--, fp->_p++;
 175                         nread++;
 176                         continue;
 177
 178                 case '*':
 179                         flags |= SUPPRESS;
 180                         goto again;
 181                 case 'l':
 182                         if( flags & LONG )
 183                                 flags |=  QUAD;
 184                         else
 185                                 flags |= LONG;
 186                         goto again;
 187                 case 'q':
 188                         flags |= QUAD;
 189                         goto again;
 190                 case 'z':
 191                         if( sizeof(size_t) == sizeof(long) )
 192                                 flags |= LONG;
 193                         if( sizeof(size_t) == sizeof(quad_t) )
 194                                 flags |= QUAD;
 195                         goto again;
 196                 case 'L':
 197                         flags |= LONGDBL;
 198                         goto again;
 199                 case 'h':
 200                         flags |= SHORT;
 201                         goto again;
 202
 203                 case '0': case '1': case '2': case '3': case '4':
 204                 case '5': case '6': case '7': case '8': case '9':
 205                         width = width * 10 + c - '0';
 206                         goto again;
 207
 208                 /*
 209                  * Conversions.
 210                  * Those marked `compat' are for 4.[123]BSD compatibility.
 211                  *
 212                  * (According to ANSI, E and X formats are supposed
 213                  * to the same as e and x.  Sorry about that.)
 214                  */
 215                 case 'D':       /* compat */
 216                         flags |= LONG;
 217                         /* FALLTHROUGH */
 218                 case 'd':
 219                         c = CT_INT;
 220                         ccfn = (u_quad_t (*)())strtoq;
 221                         base = 10;
 222                         break;
 223
 224                 case 'i':
 225                         c = CT_INT;
 226                         ccfn = (u_quad_t (*)())strtoq;
 227                         base = 0;
 228                         break;
 229
 230                 case 'O':       /* compat */
 231                         flags |= LONG;
 232                         /* FALLTHROUGH */
 233                 case 'o':
 234                         c = CT_INT;
 235                         ccfn = strtouq;
 236                         base = 8;
 237                         break;
 238
 239                 case 'u':
 240                         c = CT_INT;
 241                         ccfn = strtouq;
 242                         base = 10;
 243                         break;
 244
 245                 case 'X':       /* compat   XXX */
 246                         flags |= LONG;
 247                         /* FALLTHROUGH */
 248                 case 'x':
 249                         flags |= PFXOK; /* enable 0x prefixing */
 250                         c = CT_INT;
 251                         ccfn = strtouq;
 252                         base = 16;
 253                         break;
 254
 255 #ifdef FLOATING_POINT
 256                 case 'E':       /* compat   XXX */
 257                 case 'F':       /* compat */
 258                         flags |= LONG;
 259                         /* FALLTHROUGH */
 260                 case 'e': case 'f': case 'g':
 261                         c = CT_FLOAT;
 262                         break;
 263 #endif
 264
 265                 case 's':
 266                         c = CT_STRING;
 267                         break;
 268
 269                 case '[':
 270                         fmt = __sccl(ccltab, fmt);
 271                         flags |= NOSKIP;
 272                         c = CT_CCL;
 273                         break;
 274
 275                 case 'c':
 276                         flags |= NOSKIP;
 277                         c = CT_CHAR;
 278                         break;
 279
 280                 case 'p':       /* pointer format is like hex */
 281                         flags |= POINTER | PFXOK;
 282                         c = CT_INT;
 283                         ccfn = strtouq;
 284                         base = 16;
 285                         break;
 286
 287                 case 'n':
 288                         if (flags & SUPPRESS)   /* ??? */
 289                                 continue;
 290                         if (flags & SHORT)
 291                                 *va_arg(ap, short *) = nread;
 292                         else if (flags & LONG)
 293                                 *va_arg(ap, long *) = nread;
 294                         else if (flags & QUAD)
 295                                 *va_arg(ap, quad_t *) = nread;
 296                         else
 297                                 *va_arg(ap, int *) = nread;
 298                         continue;
 299
 300                 /*
 301                  * Disgusting backwards compatibility hacks.    XXX
 302                  */
 303                 case '\0':      /* compat */
 304                         return (EOF);
 305
 306                 default:        /* compat */
 307                         if (isupper(c))
 308                                 flags |= LONG;
 309                         c = CT_INT;
 310                         ccfn = (u_quad_t (*)())strtoq;
 311                         base = 10;
 312                         break;
 313                 }
 314
 315                 /*
 316                  * We have a conversion that requires input.
 317                  */
 318                 if (fp->_r <= 0 && __srefill(fp))
 319                         goto input_failure;
 320
 321                 /*
 322                  * Consume leading white space, except for formats
 323                  * that suppress this.
 324                  */
 325                 if ((flags & NOSKIP) == 0) {
 326                         while (isspace(*fp->_p)) {
 327                                 nread++;
 328                                 if (--fp->_r > 0)
 329                                         fp->_p++;
 330                                 else if (__srefill(fp))
 331                                         goto input_failure;
 332                         }
 333                         /*
 334                          * Note that there is at least one character in
 335                          * the buffer, so conversions that do not set NOSKIP
 336                          * ca no longer result in an input failure.
 337                          */
 338                 }
 339
 340                 /*
 341                  * Do the conversion.
 342                  */
 343                 switch (c) {
 344
 345                 case CT_CHAR:
 346                         /* scan arbitrary characters (sets NOSKIP) */
 347                         if (width == 0)
 348                                 width = 1;
 349                         if (flags & SUPPRESS) {
 350                                 size_t sum = 0;
 351                                 for (;;) {
 352                                         if ((n = fp->_r) < width) {
 353                                                 sum += n;
 354                                                 width -= n;
 355                                                 fp->_p += n;
 356                                                 if (__srefill(fp)) {
 357                                                         if (sum == 0)
 358                                                             goto input_failure;
 359                                                         break;
 360                                                 }
 361                                         } else {
 362                                                 sum += width;
 363                                                 fp->_r -= width;
 364                                                 fp->_p += width;
 365                                                 break;
 366                                         }
 367                                 }
 368                                 nread += sum;
 369                         } else {
 370                                 size_t r = fread((void *)va_arg(ap, char *), 1,
 371                                     width, fp);
 372
 373                                 if (r == 0)
 374                                         goto input_failure;
 375                                 nread += r;
 376                                 nassigned++;
 377                         }
 378                         break;
 379
 380                 case CT_CCL:
 381                         /* scan a (nonempty) character class (sets NOSKIP) */
 382                         if (width == 0)
 383                                 width = ~0;     /* `infinity' */
 384                         /* take only those things in the class */
 385                         if (flags & SUPPRESS) {
 386                                 n = 0;
 387                                 while (ccltab[*fp->_p]) {
 388                                         n++, fp->_r--, fp->_p++;
 389                                         if (--width == 0)
 390                                                 break;
 391                                         if (fp->_r <= 0 && __srefill(fp)) {
 392                                                 if (n == 0)
 393                                                         goto input_failure;
 394                                                 break;
 395                                         }
 396                                 }
 397                                 if (n == 0)
 398                                         goto match_failure;
 399                         } else {
 400                                 p0 = p = va_arg(ap, char *);
 401                                 while (ccltab[*fp->_p]) {
 402                                         fp->_r--;
 403                                         *p++ = *fp->_p++;
 404                                         if (--width == 0)
 405                                                 break;
 406                                         if (fp->_r <= 0 && __srefill(fp)) {
 407                                                 if (p == p0)
 408                                                         goto input_failure;
 409                                                 break;
 410                                         }
 411                                 }
 412                                 n = p - p0;
 413                                 if (n == 0)
 414                                         goto match_failure;
 415                                 *p = 0;
 416                                 nassigned++;
 417                         }
 418                         nread += n;
 419                         break;
 420
 421                 case CT_STRING:
 422                         /* like CCL, but zero-length string OK, & no NOSKIP */
 423                         if (width == 0)
 424                                 width = ~0;
 425                         if (flags & SUPPRESS) {
 426                                 n = 0;
 427                                 while (!isspace(*fp->_p)) {
 428                                         n++, fp->_r--, fp->_p++;
 429                                         if (--width == 0)
 430                                                 break;
 431                                         if (fp->_r <= 0 && __srefill(fp))
 432                                                 break;
 433                                 }
 434                                 nread += n;
 435                         } else {
 436                                 p0 = p = va_arg(ap, char *);
 437                                 while (!isspace(*fp->_p)) {
 438                                         fp->_r--;
 439                                         *p++ = *fp->_p++;
 440                                         if (--width == 0)
 441                                                 break;
 442                                         if (fp->_r <= 0 && __srefill(fp))
 443                                                 break;
 444                                 }
 445                                 *p = 0;
 446                                 nread += p - p0;
 447                                 nassigned++;
 448                         }
 449                         continue;
 450
 451                 case CT_INT:
 452                         /* scan an integer as if by strtoq/strtouq */
 453 #ifdef hardway
 454                         if (width == 0 || width > sizeof(buf) - 1)
 455                                 width = sizeof(buf) - 1;
 456 #else
 457                         /* size_t is unsigned, hence this optimisation */
 458                         if (--width > sizeof(buf) - 2)
 459                                 width = sizeof(buf) - 2;
 460                         width++;
 461 #endif
 462                         flags |= SIGNOK | NDIGITS | NZDIGITS;
 463                         for (p = buf; width; width--) {
 464                                 c = *fp->_p;
 465                                 /*
 466                                  * Switch on the character; `goto ok'
 467                                  * if we accept it as a part of number.
 468                                  */
 469                                 switch (c) {
 470
 471                                 /*
 472                                  * The digit 0 is always legal, but is
 473                                  * special.  For %i conversions, if no
 474                                  * digits (zero or nonzero) have been
 475                                  * scanned (only signs), we will have
 476                                  * base==0.  In that case, we should set
 477                                  * it to 8 and enable 0x prefixing.
 478                                  * Also, if we have not scanned zero digits
 479                                  * before this, do not turn off prefixing
 480                                  * (someone else will turn it off if we
 481                                  * have scanned any nonzero digits).
 482                                  */
 483                                 case '0':
 484                                         if (base == 0) {
 485                                                 base = 8;
 486                                                 flags |= PFXOK;
 487                                         }
 488                                         if (flags & NZDIGITS)
 489                                             flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
 490                                         else
 491                                             flags &= ~(SIGNOK|PFXOK|NDIGITS);
 492                                         goto ok;
 493
 494                                 /* 1 through 7 always legal */
 495                                 case '1': case '2': case '3':
 496                                 case '4': case '5': case '6': case '7':
 497                                         base = basefix[base];
 498                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 499                                         goto ok;
 500
 501                                 /* digits 8 and 9 ok iff decimal or hex */
 502                                 case '8': case '9':
 503                                         base = basefix[base];
 504                                         if (base <= 8)
 505                                                 break;  /* not legal here */
 506                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 507                                         goto ok;
 508
 509                                 /* letters ok iff hex */
 510                                 case 'A': case 'B': case 'C':
 511                                 case 'D': case 'E': case 'F':
 512                                 case 'a': case 'b': case 'c':
 513                                 case 'd': case 'e': case 'f':
 514                                         /* no need to fix base here */
 515                                         if (base <= 10)
 516                                                 break;  /* not legal here */
 517                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 518                                         goto ok;
 519
 520                                 /* sign ok only as first character */
 521                                 case '+': case '-':
 522                                         if (flags & SIGNOK) {
 523                                                 flags &= ~SIGNOK;
 524                                                 goto ok;
 525                                         }
 526                                         break;
 527
 528                                 /* x ok iff flag still set & 2nd char */
 529                                 case 'x': case 'X':
 530                                         if (flags & PFXOK && p == buf + 1) {
 531                                                 base = 16;      /* if %i */
 532                                                 flags &= ~PFXOK;
 533                                                 goto ok;
 534                                         }
 535                                         break;
 536                                 }
 537
 538                                 /*
 539                                  * If we got here, c is not a legal character
 540                                  * for a number.  Stop accumulating digits.
 541                                  */
 542                                 break;
 543                 ok:
 544                                 /*
 545                                  * c is legal: store it and look at the next.
 546                                  */
 547                                 *p++ = c;
 548                                 if (--fp->_r > 0)
 549                                         fp->_p++;
 550                                 else if (__srefill(fp))
 551                                         break;          /* EOF */
 552                         }
 553                         /*
 554                          * If we had only a sign, it is no good; push
 555                          * back the sign.  If the number ends in `x',
 556                          * it was [sign] '0' 'x', so push back the x
 557                          * and treat it as [sign] '0'.
 558                          */
 559                         if (flags & NDIGITS) {
 560                                 if (p > buf)
 561                                         (void) ungetc(*(u_char *)--p, fp);
 562                                 goto match_failure;
 563                         }
 564                         c = ((u_char *)p)[-1];
 565                         if (c == 'x' || c == 'X') {
 566                                 --p;
 567                                 (void) ungetc(c, fp);
 568                         }
 569                         if ((flags & SUPPRESS) == 0) {
 570                                 u_quad_t res;
 571
 572                                 *p = 0;
 573                                 res = (*ccfn)(buf, (char **)NULL, base);
 574                                 if (flags & POINTER)
 575                                         *va_arg(ap, void **) = (void *)res;
 576                                 else if (flags & SHORT)
 577                                         *va_arg(ap, short *) = res;
 578                                 else if (flags & QUAD)
 579                                         *va_arg(ap, quad_t *) = res;
 580                                 else if (flags & LONG)
 581                                         *va_arg(ap, long *) = res;
 582                                 else
 583                                         *va_arg(ap, int *) = res;
 584                                 nassigned++;
 585                         }
 586                         nread += p - buf;
 587                         break;
 588
 589 #ifdef FLOATING_POINT
 590                 case CT_FLOAT:
 591                         /* scan a floating point number as if by strtod */
 592 #ifdef hardway
 593                         if (width == 0 || width > sizeof(buf) - 1)
 594                                 width = sizeof(buf) - 1;
 595 #else
 596                         /* size_t is unsigned, hence this optimisation */
 597                         if (--width > sizeof(buf) - 2)
 598                                 width = sizeof(buf) - 2;
 599                         width++;
 600 #endif
 601                         flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
 602                         for (p = buf; width; width--) {
 603                                 c = *fp->_p;
 604                                 /*
 605                                  * This code mimicks the integer conversion
 606                                  * code, but is much simpler.
 607                                  */
 608                                 switch (c) {
 609
 610                                 case '0': case '1': case '2': case '3':
 611                                 case '4': case '5': case '6': case '7':
 612                                 case '8': case '9':
 613                                         flags &= ~(SIGNOK | NDIGITS);
 614                                         goto fok;
 615
 616                                 case '+': case '-':
 617                                         if (flags & SIGNOK) {
 618                                                 flags &= ~SIGNOK;
 619                                                 goto fok;
 620                                         }
 621                                         break;
 622                                 case '.':
 623                                         if (flags & DPTOK) {
 624                                                 flags &= ~(SIGNOK | DPTOK);
 625                                                 goto fok;
 626                                         }
 627                                         break;
 628                                 case 'e': case 'E':
 629                                         /* no exponent without some digits */
 630                                         if ((flags&(NDIGITS|EXPOK)) == EXPOK) {
 631                                                 flags =
 632                                                     (flags & ~(EXPOK|DPTOK)) |
 633                                                     SIGNOK | NDIGITS;
 634                                                 goto fok;
 635                                         }
 636                                         break;
 637                                 }
 638                                 break;
 639                 fok:
 640                                 *p++ = c;
 641                                 if (--fp->_r > 0)
 642                                         fp->_p++;
 643                                 else if (__srefill(fp))
 644                                         break;  /* EOF */
 645                         }
 646                         /*
 647                          * If no digits, might be missing exponent digits
 648                          * (just give back the exponent) or might be missing
 649                          * regular digits, but had sign and/or decimal point.
 650                          */
 651                         if (flags & NDIGITS) {
 652                                 if (flags & EXPOK) {
 653                                         /* no digits at all */
 654                                         while (p > buf)
 655                                                 ungetc(*(u_char *)--p, fp);
 656                                         goto match_failure;
 657                                 }
 658                                 /* just a bad exponent (e and maybe sign) */
 659                                 c = *(u_char *)--p;
 660                                 if (c != 'e' && c != 'E') {
 661                                         (void) ungetc(c, fp);/* sign */
 662                                         c = *(u_char *)--p;
 663                                 }
 664                                 (void) ungetc(c, fp);
 665                         }
 666                         if ((flags & SUPPRESS) == 0) {
 667                                 long double res;
 668
 669                                 *p = 0;
 670                                 res = strtod(buf,(char **) NULL);
 671                                 if (flags & LONGDBL)
 672                                         *va_arg(ap, long double *) = res;
 673                                 else if (flags & LONG)
 674                                         *va_arg(ap, double *) = res;
 675                                 else
 676                                         *va_arg(ap, float *) = res;
 677                                 nassigned++;
 678                         }
 679                         nread += p - buf;
 680                         break;
 681 #endif /* FLOATING_POINT */
 682                 }
 683         }
 684 input_failure:
 685         return (nassigned ? nassigned : -1);
 686 match_failure:
 687         return (nassigned);
 688 }
 689
 690 /*
 691  * Fill in the given table from the scanset at the given format
 692  * (just after `[').  Return a pointer to the character past the
 693  * closing `]'.  The table has a 1 wherever characters should be
 694  * considered part of the scanset.
 695  */
 696 static u_char *
 697 __sccl(tab, fmt)
 698         register char *tab;
 699         register u_char *fmt;
 700 {
 701         register int c, n, v;
 702
 703         /* first `clear' the whole table */
 704         c = *fmt++;             /* first char hat => negated scanset */
 705         if (c == '^') {
 706                 v = 1;          /* default => accept */
 707                 c = *fmt++;     /* get new first char */
 708         } else
 709                 v = 0;          /* default => reject */
 710         /* should probably use memset here */
 711         for (n = 0; n < 256; n++)
 712                 tab[n] = v;
 713         if (c == 0)
 714                 return (fmt - 1);/* format ended before closing ] */
 715
 716         /*
 717          * Now set the entries corresponding to the actual scanset
 718          * to the opposite of the above.
 719          *
 720          * The first character may be ']' (or '-') without being special;
 721          * the last character may be '-'.
 722          */
 723         v = 1 - v;
 724         for (;;) {
 725                 tab[c] = v;             /* take character c */
 726 doswitch:
 727                 n = *fmt++;             /* and examine the next */
 728                 switch (n) {
 729
 730                 case 0:                 /* format ended too soon */
 731                         return (fmt - 1);
 732
 733                 case '-':
 734                         /*
 735                          * A scanset of the form
 736                          *      [01+-]
 737                          * is defined as `the digit 0, the digit 1,
 738                          * the character +, the character -', but
 739                          * the effect of a scanset such as
 740                          *      [a-zA-Z0-9]
 741                          * is implementation defined.  The V7 Unix
 742                          * scanf treats `a-z' as `the letters a through
 743                          * z', but treats `a-a' as `the letter a, the
 744                          * character -, and the letter a'.
 745                          *
 746                          * For compatibility, the `-' is not considerd
 747                          * to define a range if the character following
 748                          * it is either a close bracket (required by ANSI)
 749                          * or is not numerically greater than the character
 750                          * we just stored in the table (c).
 751                          */
 752                         n = *fmt;
 753                         if (n == ']' || n < c) {
 754                                 c = '-';
 755                                 break;  /* resume the for(;;) */
 756                         }
 757                         fmt++;
 758                         do {            /* fill in the range */
 759                                 tab[++c] = v;
 760                         } while (c < n);
 761 #if 1   /* XXX another disgusting compatibility hack */
 762                         /*
 763                          * Alas, the V7 Unix scanf also treats formats
 764                          * such as [a-c-e] as `the letters a through e'.
 765                          * This too is permitted by the standard....
 766                          */
 767                         goto doswitch;
 768 #else
 769                         c = *fmt++;
 770                         if (c == 0)
 771                                 return (fmt - 1);
 772                         if (c == ']')
 773                                 return (fmt);
 774 #endif
 775                         break;
 776
 777                 case ']':               /* end of scanset */
 778                         return (fmt);
 779
 780                 default:                /* just another character */
 781                         c = n;
 782                         break;
 783                 }
 784         }
 785         /* NOTREACHED */
 786 }