contrib/sendmail/libsm/vfscanf.c

   1 /*
   2  * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Chris Torek.
   9  *
  10  * By using this file, you agree to the terms and conditions set
  11  * forth in the LICENSE file which can be found at the top level of
  12  * the sendmail distribution.
  13  */
  14
  15 #include <sm/gen.h>
  16 SM_IDSTR(id, "@(#)$Id: vfscanf.c,v 1.51 2001/09/11 04:04:49 gshapiro Exp $")
  17
  18 #include <ctype.h>
  19 #include <stdlib.h>
  20 #include <errno.h>
  21 #include <setjmp.h>
  22 #include <sys/time.h>
  23 #include <sm/varargs.h>
  24 #include <sm/config.h>
  25 #include <sm/io.h>
  26 #include <sm/signal.h>
  27 #include <sm/clock.h>
  28 #include <sm/string.h>
  29 #include "local.h"
  30
  31 #define BUF             513     /* Maximum length of numeric string. */
  32
  33 /* Flags used during conversion. */
  34 #define LONG            0x01    /* l: long or double */
  35 #define SHORT           0x04    /* h: short */
  36 #define QUAD            0x08    /* q: quad (same as ll) */
  37 #define SUPPRESS        0x10    /* suppress assignment */
  38 #define POINTER         0x20    /* weird %p pointer (`fake hex') */
  39 #define NOSKIP          0x40    /* do not skip blanks */
  40
  41 /*
  42 **  The following are used in numeric conversions only:
  43 **  SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
  44 **  SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
  45 */
  46
  47 #define SIGNOK          0x080   /* +/- is (still) legal */
  48 #define NDIGITS         0x100   /* no digits detected */
  49
  50 #define DPTOK           0x200   /* (float) decimal point is still legal */
  51 #define EXPOK           0x400   /* (float) exponent (e+3, etc) still legal */
  52
  53 #define PFXOK           0x200   /* 0x prefix is (still) legal */
  54 #define NZDIGITS        0x400   /* no zero digits detected */
  55
  56 /* Conversion types. */
  57 #define CT_CHAR         0       /* %c conversion */
  58 #define CT_CCL          1       /* %[...] conversion */
  59 #define CT_STRING       2       /* %s conversion */
  60 #define CT_INT          3       /* integer, i.e., strtoll or strtoull */
  61 #define CT_FLOAT        4       /* floating, i.e., strtod */
  62
  63 static unsigned char *sm_sccl __P((char *, unsigned char *));
  64 static jmp_buf ScanTimeOut;
  65
  66 /*
  67 **  SCANALRM -- handler when timeout activated for sm_io_vfscanf()
  68 **
  69 **  Returns flow of control to where setjmp(ScanTimeOut) was set.
  70 **
  71 **      Parameters:
  72 **              sig -- unused
  73 **
  74 **      Returns:
  75 **              does not return
  76 **
  77 **      Side Effects:
  78 **              returns flow of control to setjmp(ScanTimeOut).
  79 **
  80 **      NOTE:   THIS CAN BE CALLED FROM A SIGNAL HANDLER.  DO NOT ADD
  81 **              ANYTHING TO THIS ROUTINE UNLESS YOU KNOW WHAT YOU ARE
  82 **              DOING.
  83 */
  84
  85 /* ARGSUSED0 */
  86 static void
  87 scanalrm(sig)
  88         int sig;
  89 {
  90         longjmp(ScanTimeOut, 1);
  91 }
  92
  93 /*
  94 **  SM_VFSCANF -- convert input into data units
  95 **
  96 **      Parameters:
  97 **              fp -- file pointer for input data
  98 **              timeout -- time intvl allowed to complete (milliseconds)
  99 **              fmt0 -- format for finding data units
 100 **              ap -- vectors for memory location for storing data units
 101 **
 102 **      Results:
 103 **              Success: number of data units assigned
 104 **              Failure: SM_IO_EOF
 105 */
 106
 107 int
 108 sm_vfscanf(fp, timeout, fmt0, ap)
 109         register SM_FILE_T *fp;
 110         int SM_NONVOLATILE timeout;
 111         char const *fmt0;
 112         va_list SM_NONVOLATILE ap;
 113 {
 114         register unsigned char *SM_NONVOLATILE fmt = (unsigned char *) fmt0;
 115         register int c;         /* character from format, or conversion */
 116         register size_t width;  /* field width, or 0 */
 117         register char *p;       /* points into all kinds of strings */
 118         register int n;         /* handy integer */
 119         register int flags;     /* flags as defined above */
 120         register char *p0;      /* saves original value of p when necessary */
 121         int nassigned;          /* number of fields assigned */
 122         int nread;              /* number of characters consumed from fp */
 123         int base;               /* base argument to strtoll/strtoull */
 124         ULONGLONG_T (*ccfn)();  /* conversion function (strtoll/strtoull) */
 125         char ccltab[256];       /* character class table for %[...] */
 126         char buf[BUF];          /* buffer for numeric conversions */
 127         SM_EVENT *evt = NULL;
 128
 129         /* `basefix' is used to avoid `if' tests in the integer scanner */
 130         static short basefix[17] =
 131                 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
 132
 133         if (timeout == SM_TIME_DEFAULT)
 134                 timeout = fp->f_timeout;
 135         if (timeout == SM_TIME_IMMEDIATE)
 136         {
 137                 /*
 138                 **  Filling the buffer will take time and we are wanted to
 139                 **  return immediately. So...
 140                 */
 141
 142                 errno = EAGAIN;
 143                 return SM_IO_EOF;
 144         }
 145
 146         if (timeout != SM_TIME_FOREVER)
 147         {
 148                 if (setjmp(ScanTimeOut) != 0)
 149                 {
 150                         errno = EAGAIN;
 151                         return SM_IO_EOF;
 152                 }
 153
 154                 evt = sm_seteventm(timeout, scanalrm, 0);
 155         }
 156
 157         nassigned = 0;
 158         nread = 0;
 159         base = 0;               /* XXX just to keep gcc happy */
 160         ccfn = NULL;            /* XXX just to keep gcc happy */
 161         for (;;)
 162         {
 163                 c = *fmt++;
 164                 if (c == 0)
 165                 {
 166                         if (evt != NULL)
 167                                 sm_clrevent(evt); /*  undo our timeout */
 168                         return nassigned;
 169                 }
 170                 if (isspace(c))
 171                 {
 172                         while ((fp->f_r > 0 || sm_refill(fp, SM_TIME_FOREVER)
 173                                                 == 0) &&
 174                             isspace(*fp->f_p))
 175                                 nread++, fp->f_r--, fp->f_p++;
 176                         continue;
 177                 }
 178                 if (c != '%')
 179                         goto literal;
 180                 width = 0;
 181                 flags = 0;
 182
 183                 /*
 184                 **  switch on the format.  continue if done;
 185                 **  break once format type is derived.
 186                 */
 187
 188 again:          c = *fmt++;
 189                 switch (c)
 190                 {
 191                   case '%':
 192 literal:
 193                         if (fp->f_r <= 0 && sm_refill(fp, SM_TIME_FOREVER))
 194                                 goto input_failure;
 195                         if (*fp->f_p != c)
 196                                 goto match_failure;
 197                         fp->f_r--, fp->f_p++;
 198                         nread++;
 199                         continue;
 200
 201                   case '*':
 202                         flags |= SUPPRESS;
 203                         goto again;
 204                   case 'h':
 205                         flags |= SHORT;
 206                         goto again;
 207                   case 'l':
 208                         if (*fmt == 'l')
 209                         {
 210                                 fmt++;
 211                                 flags |= QUAD;
 212                         }
 213                         else
 214                         {
 215                                 flags |= LONG;
 216                         }
 217                         goto again;
 218                   case 'q':
 219                         flags |= QUAD;
 220                         goto again;
 221
 222                   case '0': case '1': case '2': case '3': case '4':
 223                   case '5': case '6': case '7': case '8': case '9':
 224                         width = width * 10 + c - '0';
 225                         goto again;
 226
 227                 /*
 228                 **  Conversions.
 229                 **  Those marked `compat' are for 4.[123]BSD compatibility.
 230                 **
 231                 **  (According to ANSI, E and X formats are supposed
 232                 **  to the same as e and x.  Sorry about that.)
 233                 */
 234
 235                   case 'D':     /* compat */
 236                         flags |= LONG;
 237                         /* FALLTHROUGH */
 238                   case 'd':
 239                         c = CT_INT;
 240                         ccfn = (ULONGLONG_T (*)())sm_strtoll;
 241                         base = 10;
 242                         break;
 243
 244                   case 'i':
 245                         c = CT_INT;
 246                         ccfn = (ULONGLONG_T (*)())sm_strtoll;
 247                         base = 0;
 248                         break;
 249
 250                   case 'O':     /* compat */
 251                         flags |= LONG;
 252                         /* FALLTHROUGH */
 253                   case 'o':
 254                         c = CT_INT;
 255                         ccfn = sm_strtoull;
 256                         base = 8;
 257                         break;
 258
 259                   case 'u':
 260                         c = CT_INT;
 261                         ccfn = sm_strtoull;
 262                         base = 10;
 263                         break;
 264
 265                   case 'X':
 266                   case 'x':
 267                         flags |= PFXOK; /* enable 0x prefixing */
 268                         c = CT_INT;
 269                         ccfn = sm_strtoull;
 270                         base = 16;
 271                         break;
 272
 273                   case 'E':
 274                   case 'G':
 275                   case 'e':
 276                   case 'f':
 277                   case 'g':
 278                         c = CT_FLOAT;
 279                         break;
 280
 281                   case 's':
 282                         c = CT_STRING;
 283                         break;
 284
 285                   case '[':
 286                         fmt = sm_sccl(ccltab, fmt);
 287                         flags |= NOSKIP;
 288                         c = CT_CCL;
 289                         break;
 290
 291                   case 'c':
 292                         flags |= NOSKIP;
 293                         c = CT_CHAR;
 294                         break;
 295
 296                   case 'p':     /* pointer format is like hex */
 297                         flags |= POINTER | PFXOK;
 298                         c = CT_INT;
 299                         ccfn = sm_strtoull;
 300                         base = 16;
 301                         break;
 302
 303                   case 'n':
 304                         if (flags & SUPPRESS)   /* ??? */
 305                                 continue;
 306                         if (flags & SHORT)
 307                                 *SM_VA_ARG(ap, short *) = nread;
 308                         else if (flags & LONG)
 309                                 *SM_VA_ARG(ap, long *) = nread;
 310                         else
 311                                 *SM_VA_ARG(ap, int *) = nread;
 312                         continue;
 313
 314                 /* Disgusting backwards compatibility hacks.    XXX */
 315                   case '\0':    /* compat */
 316                         if (evt != NULL)
 317                                 sm_clrevent(evt); /*  undo our timeout */
 318                         return SM_IO_EOF;
 319
 320                   default:      /* compat */
 321                         if (isupper(c))
 322                                 flags |= LONG;
 323                         c = CT_INT;
 324                         ccfn = (ULONGLONG_T (*)()) sm_strtoll;
 325                         base = 10;
 326                         break;
 327                 }
 328
 329                 /* We have a conversion that requires input. */
 330                 if (fp->f_r <= 0 && sm_refill(fp, SM_TIME_FOREVER))
 331                         goto input_failure;
 332
 333                 /*
 334                 **  Consume leading white space, except for formats
 335                 **  that suppress this.
 336                 */
 337
 338                 if ((flags & NOSKIP) == 0)
 339                 {
 340                         while (isspace(*fp->f_p))
 341                         {
 342                                 nread++;
 343                                 if (--fp->f_r > 0)
 344                                         fp->f_p++;
 345                                 else if (sm_refill(fp, SM_TIME_FOREVER))
 346                                         goto input_failure;
 347                         }
 348                         /*
 349                         **  Note that there is at least one character in
 350                         **  the buffer, so conversions that do not set NOSKIP
 351                         **  can no longer result in an input failure.
 352                         */
 353                 }
 354
 355                 /* Do the conversion. */
 356                 switch (c)
 357                 {
 358                   case CT_CHAR:
 359                         /* scan arbitrary characters (sets NOSKIP) */
 360                         if (width == 0)
 361                                 width = 1;
 362                         if (flags & SUPPRESS)
 363                         {
 364                                 size_t sum = 0;
 365                                 for (;;)
 366                                 {
 367                                         if ((size_t) (n = fp->f_r) < width)
 368                                         {
 369                                                 sum += n;
 370                                                 width -= n;
 371                                                 fp->f_p += n;
 372                                                 if (sm_refill(fp,
 373                                                               SM_TIME_FOREVER))
 374                                                 {
 375                                                         if (sum == 0)
 376                                                                 goto input_failure;
 377                                                         break;
 378                                                 }
 379                                         }
 380                                         else
 381                                         {
 382                                                 sum += width;
 383                                                 fp->f_r -= width;
 384                                                 fp->f_p += width;
 385                                                 break;
 386                                         }
 387                                 }
 388                                 nread += sum;
 389                         }
 390                         else
 391                         {
 392                                 size_t r;
 393
 394                                 r = sm_io_read(fp, SM_TIME_FOREVER,
 395                                                 (void *) SM_VA_ARG(ap, char *),
 396                                                 width);
 397                                 if (r == 0)
 398                                         goto input_failure;
 399                                 nread += r;
 400                                 nassigned++;
 401                         }
 402                         break;
 403
 404                   case CT_CCL:
 405                         /* scan a (nonempty) character class (sets NOSKIP) */
 406                         if (width == 0)
 407                                 width = (size_t)~0;     /* `infinity' */
 408
 409                         /* take only those things in the class */
 410                         if (flags & SUPPRESS)
 411                         {
 412                                 n = 0;
 413                                 while (ccltab[*fp->f_p] != '\0')
 414                                 {
 415                                         n++, fp->f_r--, fp->f_p++;
 416                                         if (--width == 0)
 417                                                 break;
 418                                         if (fp->f_r <= 0 &&
 419                                             sm_refill(fp, SM_TIME_FOREVER))
 420                                         {
 421                                                 if (n == 0) /* XXX how? */
 422                                                         goto input_failure;
 423                                                 break;
 424                                         }
 425                                 }
 426                                 if (n == 0)
 427                                         goto match_failure;
 428                         }
 429                         else
 430                         {
 431                                 p0 = p = SM_VA_ARG(ap, char *);
 432                                 while (ccltab[*fp->f_p] != '\0')
 433                                 {
 434                                         fp->f_r--;
 435                                         *p++ = *fp->f_p++;
 436                                         if (--width == 0)
 437                                                 break;
 438                                         if (fp->f_r <= 0 &&
 439                                             sm_refill(fp, SM_TIME_FOREVER))
 440                                         {
 441                                                 if (p == p0)
 442                                                         goto input_failure;
 443                                                 break;
 444                                         }
 445                                 }
 446                                 n = p - p0;
 447                                 if (n == 0)
 448                                         goto match_failure;
 449                                 *p = 0;
 450                                 nassigned++;
 451                         }
 452                         nread += n;
 453                         break;
 454
 455                   case CT_STRING:
 456                         /* like CCL, but zero-length string OK, & no NOSKIP */
 457                         if (width == 0)
 458                                 width = (size_t)~0;
 459                         if (flags & SUPPRESS)
 460                         {
 461                                 n = 0;
 462                                 while (!isspace(*fp->f_p))
 463                                 {
 464                                         n++, fp->f_r--, fp->f_p++;
 465                                         if (--width == 0)
 466                                                 break;
 467                                         if (fp->f_r <= 0 &&
 468                                             sm_refill(fp, SM_TIME_FOREVER))
 469                                                 break;
 470                                 }
 471                                 nread += n;
 472                         }
 473                         else
 474                         {
 475                                 p0 = p = SM_VA_ARG(ap, char *);
 476                                 while (!isspace(*fp->f_p))
 477                                 {
 478                                         fp->f_r--;
 479                                         *p++ = *fp->f_p++;
 480                                         if (--width == 0)
 481                                                 break;
 482                                         if (fp->f_r <= 0 &&
 483                                             sm_refill(fp, SM_TIME_FOREVER))
 484                                                 break;
 485                                 }
 486                                 *p = 0;
 487                                 nread += p - p0;
 488                                 nassigned++;
 489                         }
 490                         continue;
 491
 492                   case CT_INT:
 493                         /* scan an integer as if by strtoll/strtoull */
 494 #if SM_CONF_BROKEN_SIZE_T
 495                         if (width == 0 || width > sizeof(buf) - 1)
 496                                 width = sizeof(buf) - 1;
 497 #else /* SM_CONF_BROKEN_SIZE_T */
 498                         /* size_t is unsigned, hence this optimisation */
 499                         if (--width > sizeof(buf) - 2)
 500                                 width = sizeof(buf) - 2;
 501                         width++;
 502 #endif /* SM_CONF_BROKEN_SIZE_T */
 503                         flags |= SIGNOK | NDIGITS | NZDIGITS;
 504                         for (p = buf; width > 0; width--)
 505                         {
 506                                 c = *fp->f_p;
 507
 508                                 /*
 509                                 **  Switch on the character; `goto ok'
 510                                 **  if we accept it as a part of number.
 511                                 */
 512
 513                                 switch (c)
 514                                 {
 515
 516                                 /*
 517                                 **  The digit 0 is always legal, but is
 518                                 **  special.  For %i conversions, if no
 519                                 **  digits (zero or nonzero) have been
 520                                 **  scanned (only signs), we will have
 521                                 **  base==0.  In that case, we should set
 522                                 **  it to 8 and enable 0x prefixing.
 523                                 **  Also, if we have not scanned zero digits
 524                                 **  before this, do not turn off prefixing
 525                                 **  (someone else will turn it off if we
 526                                 **  have scanned any nonzero digits).
 527                                 */
 528
 529                                   case '0':
 530                                         if (base == 0)
 531                                         {
 532                                                 base = 8;
 533                                                 flags |= PFXOK;
 534                                         }
 535                                         if (flags & NZDIGITS)
 536                                             flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
 537                                         else
 538                                             flags &= ~(SIGNOK|PFXOK|NDIGITS);
 539                                         goto ok;
 540
 541                                 /* 1 through 7 always legal */
 542                                   case '1': case '2': case '3':
 543                                   case '4': case '5': case '6': case '7':
 544                                         base = basefix[base];
 545                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 546                                         goto ok;
 547
 548                                 /* digits 8 and 9 ok iff decimal or hex */
 549                                   case '8': case '9':
 550                                         base = basefix[base];
 551                                         if (base <= 8)
 552                                                 break;  /* not legal here */
 553                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 554                                         goto ok;
 555
 556                                 /* letters ok iff hex */
 557                                   case 'A': case 'B': case 'C':
 558                                   case 'D': case 'E': case 'F':
 559                                   case 'a': case 'b': case 'c':
 560                                   case 'd': case 'e': case 'f':
 561
 562                                         /* no need to fix base here */
 563                                         if (base <= 10)
 564                                                 break;  /* not legal here */
 565                                         flags &= ~(SIGNOK | PFXOK | NDIGITS);
 566                                         goto ok;
 567
 568                                 /* sign ok only as first character */
 569                                   case '+': case '-':
 570                                         if (flags & SIGNOK)
 571                                         {
 572                                                 flags &= ~SIGNOK;
 573                                                 goto ok;
 574                                         }
 575                                         break;
 576
 577                                 /* x ok iff flag still set & 2nd char */
 578                                   case 'x': case 'X':
 579                                         if (flags & PFXOK && p == buf + 1)
 580                                         {
 581                                                 base = 16;      /* if %i */
 582                                                 flags &= ~PFXOK;
 583                                                 goto ok;
 584                                         }
 585                                         break;
 586                                 }
 587
 588                                 /*
 589                                 **  If we got here, c is not a legal character
 590                                 **  for a number.  Stop accumulating digits.
 591                                 */
 592
 593                                 break;
 594                 ok:
 595                                 /* c is legal: store it and look at the next. */
 596                                 *p++ = c;
 597                                 if (--fp->f_r > 0)
 598                                         fp->f_p++;
 599                                 else if (sm_refill(fp, SM_TIME_FOREVER))
 600                                         break;          /* SM_IO_EOF */
 601                         }
 602
 603                         /*
 604                         **  If we had only a sign, it is no good; push
 605                         **  back the sign.  If the number ends in `x',
 606                         **  it was [sign] '0' 'x', so push back the x
 607                         **  and treat it as [sign] '0'.
 608                         */
 609
 610                         if (flags & NDIGITS)
 611                         {
 612                                 if (p > buf)
 613                                         (void) sm_io_ungetc(fp, SM_TIME_DEFAULT,
 614                                                             *(unsigned char *)--p);
 615                                 goto match_failure;
 616                         }
 617                         c = ((unsigned char *)p)[-1];
 618                         if (c == 'x' || c == 'X')
 619                         {
 620                                 --p;
 621                                 (void) sm_io_ungetc(fp, SM_TIME_DEFAULT, c);
 622                         }
 623                         if ((flags & SUPPRESS) == 0)
 624                         {
 625                                 ULONGLONG_T res;
 626
 627                                 *p = 0;
 628                                 res = (*ccfn)(buf, (char **)NULL, base);
 629                                 if (flags & POINTER)
 630                                         *SM_VA_ARG(ap, void **) =
 631                                             (void *)(long) res;
 632                                 else if (flags & QUAD)
 633                                         *SM_VA_ARG(ap, LONGLONG_T *) = res;
 634                                 else if (flags & LONG)
 635                                         *SM_VA_ARG(ap, long *) = res;
 636                                 else if (flags & SHORT)
 637                                         *SM_VA_ARG(ap, short *) = res;
 638                                 else
 639                                         *SM_VA_ARG(ap, int *) = res;
 640                                 nassigned++;
 641                         }
 642                         nread += p - buf;
 643                         break;
 644
 645                   case CT_FLOAT:
 646                         /* scan a floating point number as if by strtod */
 647                         if (width == 0 || width > sizeof(buf) - 1)
 648                                 width = sizeof(buf) - 1;
 649                         flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
 650                         for (p = buf; width; width--)
 651                         {
 652                                 c = *fp->f_p;
 653
 654                                 /*
 655                                 **  This code mimicks the integer conversion
 656                                 **  code, but is much simpler.
 657                                 */
 658
 659                                 switch (c)
 660                                 {
 661
 662                                   case '0': case '1': case '2': case '3':
 663                                   case '4': case '5': case '6': case '7':
 664                                   case '8': case '9':
 665                                         flags &= ~(SIGNOK | NDIGITS);
 666                                         goto fok;
 667
 668                                   case '+': case '-':
 669                                         if (flags & SIGNOK)
 670                                         {
 671                                                 flags &= ~SIGNOK;
 672                                                 goto fok;
 673                                         }
 674                                         break;
 675                                   case '.':
 676                                         if (flags & DPTOK)
 677                                         {
 678                                                 flags &= ~(SIGNOK | DPTOK);
 679                                                 goto fok;
 680                                         }
 681                                         break;
 682                                   case 'e': case 'E':
 683
 684                                         /* no exponent without some digits */
 685                                         if ((flags&(NDIGITS|EXPOK)) == EXPOK)
 686                                         {
 687                                                 flags =
 688                                                     (flags & ~(EXPOK|DPTOK)) |
 689                                                     SIGNOK | NDIGITS;
 690                                                 goto fok;
 691                                         }
 692                                         break;
 693                                 }
 694                                 break;
 695                 fok:
 696                                 *p++ = c;
 697                                 if (--fp->f_r > 0)
 698                                         fp->f_p++;
 699                                 else if (sm_refill(fp, SM_TIME_FOREVER))
 700                                         break;  /* SM_IO_EOF */
 701                         }
 702
 703                         /*
 704                         **  If no digits, might be missing exponent digits
 705                         **  (just give back the exponent) or might be missing
 706                         **  regular digits, but had sign and/or decimal point.
 707                         */
 708
 709                         if (flags & NDIGITS)
 710                         {
 711                                 if (flags & EXPOK)
 712                                 {
 713                                         /* no digits at all */
 714                                         while (p > buf)
 715                                                 (void) sm_io_ungetc(fp,
 716                                                              SM_TIME_DEFAULT,
 717                                                              *(unsigned char *)--p);
 718                                         goto match_failure;
 719                                 }
 720
 721                                 /* just a bad exponent (e and maybe sign) */
 722                                 c = *(unsigned char *) --p;
 723                                 if (c != 'e' && c != 'E')
 724                                 {
 725                                         (void) sm_io_ungetc(fp, SM_TIME_DEFAULT,
 726                                                             c); /* sign */
 727                                         c = *(unsigned char *)--p;
 728                                 }
 729                                 (void) sm_io_ungetc(fp, SM_TIME_DEFAULT, c);
 730                         }
 731                         if ((flags & SUPPRESS) == 0)
 732                         {
 733                                 double res;
 734
 735                                 *p = 0;
 736                                 res = strtod(buf, (char **) NULL);
 737                                 if (flags & LONG)
 738                                         *SM_VA_ARG(ap, double *) = res;
 739                                 else
 740                                         *SM_VA_ARG(ap, float *) = res;
 741                                 nassigned++;
 742                         }
 743                         nread += p - buf;
 744                         break;
 745                 }
 746         }
 747 input_failure:
 748         if (evt != NULL)
 749                 sm_clrevent(evt); /*  undo our timeout */
 750         return nassigned ? nassigned : -1;
 751 match_failure:
 752         if (evt != NULL)
 753                 sm_clrevent(evt); /*  undo our timeout */
 754         return nassigned;
 755 }
 756
 757 /*
 758 **  SM_SCCL -- sequenced character comparison list
 759 **
 760 **  Fill in the given table from the scanset at the given format
 761 **  (just after `[').  Return a pointer to the character past the
 762 **  closing `]'.  The table has a 1 wherever characters should be
 763 **  considered part of the scanset.
 764 **
 765 **      Parameters:
 766 **              tab -- array flagging "active" char's to match (returned)
 767 **              fmt -- character list (within "[]")
 768 **
 769 **      Results:
 770 */
 771
 772 static unsigned char *
 773 sm_sccl(tab, fmt)
 774         register char *tab;
 775         register unsigned char *fmt;
 776 {
 777         register int c, n, v;
 778
 779         /* first `clear' the whole table */
 780         c = *fmt++;             /* first char hat => negated scanset */
 781         if (c == '^')
 782         {
 783                 v = 1;          /* default => accept */
 784                 c = *fmt++;     /* get new first char */
 785         }
 786         else
 787                 v = 0;          /* default => reject */
 788
 789         /* should probably use memset here */
 790         for (n = 0; n < 256; n++)
 791                 tab[n] = v;
 792         if (c == 0)
 793                 return fmt - 1; /* format ended before closing ] */
 794
 795         /*
 796         **  Now set the entries corresponding to the actual scanset
 797         **  to the opposite of the above.
 798         **
 799         **  The first character may be ']' (or '-') without being special;
 800         **  the last character may be '-'.
 801         */
 802
 803         v = 1 - v;
 804         for (;;)
 805         {
 806                 tab[c] = v;             /* take character c */
 807 doswitch:
 808                 n = *fmt++;             /* and examine the next */
 809                 switch (n)
 810                 {
 811
 812                   case 0:                       /* format ended too soon */
 813                         return fmt - 1;
 814
 815                   case '-':
 816                         /*
 817                         **  A scanset of the form
 818                         **      [01+-]
 819                         **  is defined as `the digit 0, the digit 1,
 820                         **  the character +, the character -', but
 821                         **  the effect of a scanset such as
 822                         **      [a-zA-Z0-9]
 823                         **  is implementation defined.  The V7 Unix
 824                         **  scanf treats `a-z' as `the letters a through
 825                         **  z', but treats `a-a' as `the letter a, the
 826                         **  character -, and the letter a'.
 827                         **
 828                         **  For compatibility, the `-' is not considerd
 829                         **  to define a range if the character following
 830                         **  it is either a close bracket (required by ANSI)
 831                         **  or is not numerically greater than the character
 832                         **  we just stored in the table (c).
 833                         */
 834
 835                         n = *fmt;
 836                         if (n == ']' || n < c)
 837                         {
 838                                 c = '-';
 839                                 break;  /* resume the for(;;) */
 840                         }
 841                         fmt++;
 842                         do
 843                         {
 844                                 /* fill in the range */
 845                                 tab[++c] = v;
 846                         } while (c < n);
 847 #if 1   /* XXX another disgusting compatibility hack */
 848
 849                         /*
 850                         **  Alas, the V7 Unix scanf also treats formats
 851                         **  such as [a-c-e] as `the letters a through e'.
 852                         **  This too is permitted by the standard....
 853                         */
 854
 855                         goto doswitch;
 856 #else
 857                         c = *fmt++;
 858                         if (c == 0)
 859                                 return fmt - 1;
 860                         if (c == ']')
 861                                 return fmt;
 862                         break;
 863 #endif
 864
 865                   case ']':             /* end of scanset */
 866                         return fmt;
 867
 868                   default:              /* just another character */
 869                         c = n;
 870                         break;
 871                 }
 872         }
 873         /* NOTREACHED */
 874 }