lib/libc/stdio/vfscanf.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Chris Torek.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * @(#)vfscanf.c        8.1 (Berkeley) 6/4/93
  37  * $FreeBSD: src/lib/libc/stdio/vfscanf.c,v 1.14.2.2 2002/04/17 14:58:23 ache Exp $
  38  * $DragonFly: src/lib/libc/stdio/vfscanf.c,v 1.3 2004/03/08 07:55:57 hmp Exp $
  39  */
  40
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <ctype.h>
  44 #if __STDC__
  45 #include <stdarg.h>
  46 #else
  47 #include <varargs.h>
  48 #endif
  49 #include <string.h>
  50
  51 #include "collate.h"
  52 #include "local.h"
  53
  54 #define FLOATING_POINT
  55
  56 #ifdef FLOATING_POINT
  57 #include <locale.h>
  58 #include "floatio.h"
  59 #endif
  60
  61 #define BUF             513     /* Maximum length of numeric string. */
  62
  63 /*
  64  * Flags used during conversion.
  65  */
  66 #define LONG            0x01    /* l: long or double */
  67 #define LONGDBL         0x02    /* L: long double */
  68 #define SHORT           0x04    /* h: short */
  69 #define SUPPRESS        0x08    /* suppress assignment */
  70 #define POINTER         0x10    /* weird %p pointer (`fake hex') */
  71 #define NOSKIP          0x20    /* do not skip blanks */
  72 #define QUAD            0x400
  73
  74 /*
  75  * The following are used in numeric conversions only:
  76  * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
  77  * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
  78  */
  79 #define SIGNOK          0x40    /* +/- is (still) legal */
  80 #define NDIGITS         0x80    /* no digits detected */
  81
  82 #define DPTOK           0x100   /* (float) decimal point is still legal */
  83 #define EXPOK           0x200   /* (float) exponent (e+3, etc) still legal */
  84
  85 #define PFXOK           0x100   /* 0x prefix is (still) legal */
  86 #define NZDIGITS        0x200   /* no zero digits detected */
  87 #define HAVESIGN        0x10000 /* sign detected */
  88
  89 /*
  90  * Conversion types.
  91  */
  92 #define CT_CHAR         0       /* %c conversion */
  93 #define CT_CCL          1       /* %[...] conversion */
  94 #define CT_STRING       2       /* %s conversion */
  95 #define CT_INT          3       /* integer, i.e., strtoq or strtouq */
  96 #define CT_FLOAT        4       /* floating, i.e., strtod */
  97
  98 #define u_char unsigned char
  99 #define u_long unsigned long
 100
 101 static u_char *__sccl(char *, u_char *);
 102
 103 /*
 104  * vfscanf
 105  */
 106 int
 107 __svfscanf(FILE *fp, char const *fmt0, va_list ap)
 108 {
 109         u_char *fmt = (u_char *)fmt0;
 110         int c;                  /* character from format, or conversion */
 111         size_t width;           /* field width, or 0 */
 112         char *p;                /* points into all kinds of strings */
 113         int n;                  /* handy integer */
 114         int flags;              /* flags as defined above */
 115         char *p0;               /* saves original value of p when necessary */
 116         int nassigned;          /* number of fields assigned */
 117         int nconversions;       /* number of conversions */
 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 #ifdef FLOATING_POINT
 128         char decimal_point = localeconv()->decimal_point[0];
 129 #endif
 130
 131         nassigned = 0;
 132         nconversions = 0;
 133         nread = 0;
 134         base = 0;               /* XXX just to keep gcc happy */
 135         ccfn = NULL;            /* XXX just to keep gcc happy */
 136         for (;;) {
 137                 c = *fmt++;
 138                 if (c == 0)
 139                         return (nassigned);
 140                 if (isspace(c)) {
 141                         while ((fp->_r > 0 || __srefill(fp) == 0) && isspace(*fp->_p))
 142                                 nread++, fp->_r--, fp->_p++;
 143                         continue;
 144                 }
 145                 if (c != '%')
 146                         goto literal;
 147                 width = 0;
 148                 flags = 0;
 149                 /*
 150                  * switch on the format.  continue if done;
 151                  * break once format type is derived.
 152                  */
 153 again:          c = *fmt++;
 154                 switch (c) {
 155                 case '%':
 156 literal:
 157                         if (fp->_r <= 0 && __srefill(fp))
 158                                 goto input_failure;
 159                         if (*fp->_p != c)
 160                                 goto match_failure;
 161                         fp->_r--, fp->_p++;
 162                         nread++;
 163                         continue;
 164
 165                 case '*':
 166                         flags |= SUPPRESS;
 167                         goto again;
 168                 case 'l':
 169                         flags |= LONG;
 170                         goto again;
 171                 case 'q':
 172                         flags |= QUAD;
 173                         goto again;
 174                 case 'L':
 175                         flags |= LONGDBL;
 176                         goto again;
 177                 case 'h':
 178                         flags |= SHORT;
 179                         goto again;
 180
 181                 case '0': case '1': case '2': case '3': case '4':
 182                 case '5': case '6': case '7': case '8': case '9':
 183                         width = width * 10 + c - '0';
 184                         goto again;
 185
 186                 /*
 187                  * Conversions.
 188                  * Those marked `compat' are for 4.[123]BSD compatibility.
 189                  *
 190                  * (According to ANSI, E and X formats are supposed
 191                  * to the same as e and x.  Sorry about that.)
 192                  */
 193                 case 'D':       /* compat */
 194                         flags |= LONG;
 195                         /* FALLTHROUGH */
 196                 case 'd':
 197                         c = CT_INT;
 198                         ccfn = (u_quad_t (*)())strtoq;
 199                         base = 10;
 200                         break;
 201
 202                 case 'i':
 203                         c = CT_INT;
 204                         ccfn = (u_quad_t (*)())strtoq;
 205                         base = 0;
 206                         break;
 207
 208                 case 'O':       /* compat */
 209                         flags |= LONG;
 210                         /* FALLTHROUGH */
 211                 case 'o':
 212                         c = CT_INT;
 213                         ccfn = strtouq;
 214                         base = 8;
 215                         break;
 216
 217                 case 'u':
 218                         c = CT_INT;
 219                         ccfn = strtouq;
 220                         base = 10;
 221                         break;
 222
 223                 case 'X':       /* compat   XXX */
 224                         flags |= LONG;
 225                         /* FALLTHROUGH */
 226                 case 'x':
 227                         flags |= PFXOK; /* enable 0x prefixing */
 228                         c = CT_INT;
 229                         ccfn = strtouq;
 230                         base = 16;
 231                         break;
 232
 233 #ifdef FLOATING_POINT
 234                 case 'E':       /* compat   XXX */
 235                 case 'F':       /* compat */
 236                         flags |= LONG;
 237                         /* FALLTHROUGH */
 238                 case 'e': case 'f': case 'g':
 239                         c = CT_FLOAT;
 240                         break;
 241 #endif
 242
 243                 case 's':
 244                         c = CT_STRING;
 245                         break;
 246
 247                 case '[':
 248                         fmt = __sccl(ccltab, fmt);
 249                         flags |= NOSKIP;
 250                         c = CT_CCL;
 251                         break;
 252
 253                 case 'c':
 254                         flags |= NOSKIP;
 255                         c = CT_CHAR;
 256                         break;
 257
 258                 case 'p':       /* pointer format is like hex */
 259                         flags |= POINTER | PFXOK;
 260                         c = CT_INT;
 261                         ccfn = strtouq;
 262                         base = 16;
 263                         break;
 264
 265                 case 'n':
 266                         nconversions++;
 267                         if (flags & SUPPRESS)   /* ??? */
 268                                 continue;
 269                         if (flags & SHORT)
 270                                 *va_arg(ap, short *) = nread;
 271                         else if (flags & LONG)
 272                                 *va_arg(ap, long *) = nread;
 273                         else if (flags & QUAD)
 274                                 *va_arg(ap, quad_t *) = nread;
 275                         else
 276                                 *va_arg(ap, int *) = nread;
 277                         continue;
 278
 279                 /*
 280                  * Disgusting backwards compatibility hacks.    XXX
 281                  */
 282                 case '\0':      /* compat */
 283                         return (EOF);
 284
 285                 default:        /* compat */
 286                         if (isupper(c))
 287                                 flags |= LONG;
 288                         c = CT_INT;
 289                         ccfn = (u_quad_t (*)())strtoq;
 290                         base = 10;
 291                         break;
 292                 }
 293
 294                 /*
 295                  * We have a conversion that requires input.
 296                  */
 297                 if (fp->_r <= 0 && __srefill(fp))
 298                         goto input_failure;
 299
 300                 /*
 301                  * Consume leading white space, except for formats
 302                  * that suppress this.
 303                  */
 304                 if ((flags & NOSKIP) == 0) {
 305                         while (isspace(*fp->_p)) {
 306                                 nread++;
 307                                 if (--fp->_r > 0)
 308                                         fp->_p++;
 309                                 else if (__srefill(fp))
 310                                         goto input_failure;
 311                         }
 312                         /*
 313                          * Note that there is at least one character in
 314                          * the buffer, so conversions that do not set NOSKIP
 315                          * ca no longer result in an input failure.
 316                          */
 317                 }
 318
 319                 /*
 320                  * Do the conversion.
 321                  */
 322                 switch (c) {
 323
 324                 case CT_CHAR:
 325                         /* scan arbitrary characters (sets NOSKIP) */
 326                         if (width == 0)
 327                                 width = 1;
 328                         if (flags & SUPPRESS) {
 329                                 size_t sum = 0;
 330                                 for (;;) {
 331                                         if ((n = fp->_r) < width) {
 332                                                 sum += n;
 333                                                 width -= n;
 334                                                 fp->_p += n;
 335                                                 if (__srefill(fp)) {
 336                                                         if (sum == 0)
 337                                                             goto input_failure;
 338                                                         break;
 339                                                 }
 340                                         } else {
 341                                                 sum += width;
 342                                                 fp->_r -= width;
 343                                                 fp->_p += width;
 344                                                 break;
 345                                         }
 346                                 }
 347                                 nread += sum;
 348                         } else {
 349                                 size_t r = fread((void *)va_arg(ap, char *), 1,
 350                                     width, fp);
 351
 352                                 if (r == 0)
 353                                         goto input_failure;
 354                                 nread += r;
 355                                 nassigned++;
 356                         }
 357                         nconversions++;
 358                         break;
 359
 360                 case CT_CCL:
 361                         /* scan a (nonempty) character class (sets NOSKIP) */
 362                         if (width == 0)
 363                                 width = (size_t)~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                         nconversions++;
 400                         break;
 401
 402                 case CT_STRING:
 403                         /* like CCL, but zero-length string OK, & no NOSKIP */
 404                         if (width == 0)
 405                                 width = (size_t)~0;
 406                         if (flags & SUPPRESS) {
 407                                 n = 0;
 408                                 while (!isspace(*fp->_p)) {
 409                                         n++, fp->_r--, fp->_p++;
 410                                         if (--width == 0)
 411                                                 break;
 412                                         if (fp->_r <= 0 && __srefill(fp))
 413                                                 break;
 414                                 }
 415                                 nread += n;
 416                         } else {
 417                                 p0 = p = va_arg(ap, char *);
 418                                 while (!isspace(*fp->_p)) {
 419                                         fp->_r--;
 420                                         *p++ = *fp->_p++;
 421                                         if (--width == 0)
 422                                                 break;
 423                                         if (fp->_r <= 0 && __srefill(fp))
 424                                                 break;
 425                                 }
 426                                 *p = 0;
 427                                 nread += p - p0;
 428                                 nassigned++;
 429                         }
 430                         nconversions++;
 431                         continue;
 432
 433                 case CT_INT:
 434                         /* scan an integer as if by strtoq/strtouq */
 435 #ifdef hardway
 436                         if (width == 0 || width > sizeof(buf) - 1)
 437                                 width = sizeof(buf) - 1;
 438 #else
 439                         /* size_t is unsigned, hence this optimisation */
 440                         if (--width > sizeof(buf) - 2)
 441                                 width = sizeof(buf) - 2;
 442                         width++;
 443 #endif
 444                         flags |= SIGNOK | NDIGITS | NZDIGITS;
 445                         for (p = buf; width; width--) {
 446                                 c = *fp->_p;
 447                                 /*
 448                                  * Switch on the character; `goto ok'
 449                                  * if we accept it as a part of number.
 450                                  */
 451                                 switch (c) {
 452
 453                                 /*
 454                                  * The digit 0 is always legal, but is
 455                                  * special.  For %i conversions, if no
 456                                  * digits (zero or nonzero) have been
 457                                  * scanned (only signs), we will have
 458                                  * base==0.  In that case, we should set
 459                                  * it to 8 and enable 0x prefixing.
 460                                  * Also, if we have not scanned zero digits
 461                                  * before this, do not turn off prefixing
 462                                  * (someone else will turn it off if we
 463                                  * have scanned any nonzero digits).
 464                                  */
 465                                 case '0':
 466                                         if (base == 0) {
 467                                                 base = 8;
 468                                                 flags |= PFXOK;
 469                                         }
 470                                         if (flags & NZDIGITS)
 471                                             flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
 472                                         else
 473                                             flags &= ~(SIGNOK|PFXOK|NDIGITS);
 474                                         goto ok;
 475
 476                                 /* 1 through 7 always legal */
 477                                 case '1': case '2': case '3':
 478                                 case '4': case '5': case '6': case '7':
 479                                         base = basefix[base];
 480                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 481                                         goto ok;
 482
 483                                 /* digits 8 and 9 ok iff decimal or hex */
 484                                 case '8': case '9':
 485                                         base = basefix[base];
 486                                         if (base <= 8)
 487                                                 break;  /* not legal here */
 488                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 489                                         goto ok;
 490
 491                                 /* letters ok iff hex */
 492                                 case 'A': case 'B': case 'C':
 493                                 case 'D': case 'E': case 'F':
 494                                 case 'a': case 'b': case 'c':
 495                                 case 'd': case 'e': case 'f':
 496                                         /* no need to fix base here */
 497                                         if (base <= 10)
 498                                                 break;  /* not legal here */
 499                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 500                                         goto ok;
 501
 502                                 /* sign ok only as first character */
 503                                 case '+': case '-':
 504                                         if (flags & SIGNOK) {
 505                                                 flags &= ~SIGNOK;
 506                                                 flags |= HAVESIGN;
 507                                                 goto ok;
 508                                         }
 509                                         break;
 510
 511                                 /*
 512                                  * x ok iff flag still set & 2nd char (or
 513                                  * 3rd char if we have a sign).
 514                                  */
 515                                 case 'x': case 'X':
 516                                         if (flags & PFXOK && p ==
 517                                             buf + 1 + !!(flags & HAVESIGN)) {
 518                                                 base = 16;      /* if %i */
 519                                                 flags &= ~PFXOK;
 520                                                 goto ok;
 521                                         }
 522                                         break;
 523                                 }
 524
 525                                 /*
 526                                  * If we got here, c is not a legal character
 527                                  * for a number.  Stop accumulating digits.
 528                                  */
 529                                 break;
 530                 ok:
 531                                 /*
 532                                  * c is legal: store it and look at the next.
 533                                  */
 534                                 *p++ = c;
 535                                 if (--fp->_r > 0)
 536                                         fp->_p++;
 537                                 else if (__srefill(fp))
 538                                         break;          /* EOF */
 539                         }
 540                         /*
 541                          * If we had only a sign, it is no good; push
 542                          * back the sign.  If the number ends in `x',
 543                          * it was [sign] '0' 'x', so push back the x
 544                          * and treat it as [sign] '0'.
 545                          */
 546                         if (flags & NDIGITS) {
 547                                 if (p > buf)
 548                                         (void) ungetc(*(u_char *)--p, fp);
 549                                 goto match_failure;
 550                         }
 551                         c = ((u_char *)p)[-1];
 552                         if (c == 'x' || c == 'X') {
 553                                 --p;
 554                                 (void) ungetc(c, fp);
 555                         }
 556                         if ((flags & SUPPRESS) == 0) {
 557                                 u_quad_t res;
 558
 559                                 *p = 0;
 560                                 res = (*ccfn)(buf, (char **)NULL, base);
 561                                 if (flags & POINTER)
 562                                         *va_arg(ap, void **) =
 563                                                 (void *)(u_long)res;
 564                                 else if (flags & SHORT)
 565                                         *va_arg(ap, short *) = res;
 566                                 else if (flags & LONG)
 567                                         *va_arg(ap, long *) = res;
 568                                 else if (flags & QUAD)
 569                                         *va_arg(ap, quad_t *) = res;
 570                                 else
 571                                         *va_arg(ap, int *) = res;
 572                                 nassigned++;
 573                         }
 574                         nread += p - buf;
 575                         nconversions++;
 576                         break;
 577
 578 #ifdef FLOATING_POINT
 579                 case CT_FLOAT:
 580                         /* scan a floating point number as if by strtod */
 581 #ifdef hardway
 582                         if (width == 0 || width > sizeof(buf) - 1)
 583                                 width = sizeof(buf) - 1;
 584 #else
 585                         /* size_t is unsigned, hence this optimisation */
 586                         if (--width > sizeof(buf) - 2)
 587                                 width = sizeof(buf) - 2;
 588                         width++;
 589 #endif
 590                         flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
 591                         for (p = buf; width; width--) {
 592                                 c = *fp->_p;
 593                                 /*
 594                                  * This code mimicks the integer conversion
 595                                  * code, but is much simpler.
 596                                  */
 597                                 switch (c) {
 598
 599                                 case '0': case '1': case '2': case '3':
 600                                 case '4': case '5': case '6': case '7':
 601                                 case '8': case '9':
 602                                         flags &= ~(SIGNOK | NDIGITS);
 603                                         goto fok;
 604
 605                                 case '+': case '-':
 606                                         if (flags & SIGNOK) {
 607                                                 flags &= ~SIGNOK;
 608                                                 goto fok;
 609                                         }
 610                                         break;
 611                                 case 'e': case 'E':
 612                                         /* no exponent without some digits */
 613                                         if ((flags&(NDIGITS|EXPOK)) == EXPOK) {
 614                                                 flags =
 615                                                     (flags & ~(EXPOK|DPTOK)) |
 616                                                     SIGNOK | NDIGITS;
 617                                                 goto fok;
 618                                         }
 619                                         break;
 620                                 default:
 621                                         if ((char)c == decimal_point &&
 622                                             (flags & DPTOK)) {
 623                                                 flags &= ~(SIGNOK | DPTOK);
 624                                                 goto fok;
 625                                         }
 626                                         break;
 627                                 }
 628                                 break;
 629                 fok:
 630                                 *p++ = c;
 631                                 if (--fp->_r > 0)
 632                                         fp->_p++;
 633                                 else if (__srefill(fp))
 634                                         break;  /* EOF */
 635                         }
 636                         /*
 637                          * If no digits, might be missing exponent digits
 638                          * (just give back the exponent) or might be missing
 639                          * regular digits, but had sign and/or decimal point.
 640                          */
 641                         if (flags & NDIGITS) {
 642                                 if (flags & EXPOK) {
 643                                         /* no digits at all */
 644                                         while (p > buf)
 645                                                 ungetc(*(u_char *)--p, fp);
 646                                         goto match_failure;
 647                                 }
 648                                 /* just a bad exponent (e and maybe sign) */
 649                                 c = *(u_char *)--p;
 650                                 if (c != 'e' && c != 'E') {
 651                                         (void) ungetc(c, fp);/* sign */
 652                                         c = *(u_char *)--p;
 653                                 }
 654                                 (void) ungetc(c, fp);
 655                         }
 656                         if ((flags & SUPPRESS) == 0) {
 657                                 double res;
 658
 659                                 *p = 0;
 660                                 /* XXX this loses precision for long doubles. */
 661                                 res = strtod(buf, (char **) NULL);
 662                                 if (flags & LONGDBL)
 663                                         *va_arg(ap, long double *) = res;
 664                                 else if (flags & LONG)
 665                                         *va_arg(ap, double *) = res;
 666                                 else
 667                                         *va_arg(ap, float *) = res;
 668                                 nassigned++;
 669                         }
 670                         nread += p - buf;
 671                         nconversions++;
 672                         break;
 673 #endif /* FLOATING_POINT */
 674                 }
 675         }
 676 input_failure:
 677         return (nconversions != 0 ? nassigned : EOF);
 678 match_failure:
 679         return (nassigned);
 680 }
 681
 682 /*
 683  * Fill in the given table from the scanset at the given format
 684  * (just after `[').  Return a pointer to the character past the
 685  * closing `]'.  The table has a 1 wherever characters should be
 686  * considered part of the scanset.
 687  */
 688 static u_char *
 689 __sccl(tab, fmt)
 690         char *tab;
 691         u_char *fmt;
 692 {
 693         int c, n, v, i;
 694
 695         /* first `clear' the whole table */
 696         c = *fmt++;             /* first char hat => negated scanset */
 697         if (c == '^') {
 698                 v = 1;          /* default => accept */
 699                 c = *fmt++;     /* get new first char */
 700         } else
 701                 v = 0;          /* default => reject */
 702
 703         /* XXX: Will not work if sizeof(tab*) > sizeof(char) */
 704         (void) memset(tab, v, 256);
 705
 706         if (c == 0)
 707                 return (fmt - 1);/* format ended before closing ] */
 708
 709         /*
 710          * Now set the entries corresponding to the actual scanset
 711          * to the opposite of the above.
 712          *
 713          * The first character may be ']' (or '-') without being special;
 714          * the last character may be '-'.
 715          */
 716         v = 1 - v;
 717         for (;;) {
 718                 tab[c] = v;             /* take character c */
 719 doswitch:
 720                 n = *fmt++;             /* and examine the next */
 721                 switch (n) {
 722
 723                 case 0:                 /* format ended too soon */
 724                         return (fmt - 1);
 725
 726                 case '-':
 727                         /*
 728                          * A scanset of the form
 729                          *      [01+-]
 730                          * is defined as `the digit 0, the digit 1,
 731                          * the character +, the character -', but
 732                          * the effect of a scanset such as
 733                          *      [a-zA-Z0-9]
 734                          * is implementation defined.  The V7 Unix
 735                          * scanf treats `a-z' as `the letters a through
 736                          * z', but treats `a-a' as `the letter a, the
 737                          * character -, and the letter a'.
 738                          *
 739                          * For compatibility, the `-' is not considerd
 740                          * to define a range if the character following
 741                          * it is either a close bracket (required by ANSI)
 742                          * or is not numerically greater than the character
 743                          * we just stored in the table (c).
 744                          */
 745                         n = *fmt;
 746                         if (n == ']'
 747                             || (__collate_load_error ? n < c :
 748                                 __collate_range_cmp (n, c) < 0
 749                                )
 750                            ) {
 751                                 c = '-';
 752                                 break;  /* resume the for(;;) */
 753                         }
 754                         fmt++;
 755                         /* fill in the range */
 756                         if (__collate_load_error) {
 757                                 do {
 758                                         tab[++c] = v;
 759                                 } while (c < n);
 760                         } else {
 761                                 for (i = 0; i < 256; i ++)
 762                                         if (   __collate_range_cmp (c, i) < 0
 763                                             && __collate_range_cmp (i, n) <= 0
 764                                            )
 765                                                 tab[i] = v;
 766                         }
 767 #if 1   /* XXX another disgusting compatibility hack */
 768                         c = n;
 769                         /*
 770                          * Alas, the V7 Unix scanf also treats formats
 771                          * such as [a-c-e] as `the letters a through e'.
 772                          * This too is permitted by the standard....
 773                          */
 774                         goto doswitch;
 775 #else
 776                         c = *fmt++;
 777                         if (c == 0)
 778                                 return (fmt - 1);
 779                         if (c == ']')
 780                                 return (fmt);
 781 #endif
 782                         break;
 783
 784                 case ']':               /* end of scanset */
 785                         return (fmt);
 786
 787                 default:                /* just another character */
 788                         c = n;
 789                         break;
 790                 }
 791         }
 792         /* NOTREACHED */
 793 }