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tscan.c

/*
 * Copyright (c) 2001-2002 The Trustees of Indiana University.  
 *                         All rights reserved.
 * Copyright (c) 1998-2001 University of Notre Dame. 
 *                         All rights reserved.
 * Copyright (c) 1994-1998 The Ohio State University.  
 *                         All rights reserved.
 * 
 * $HEADER$
 *
 *    Very confusing software.  See offeeecial copyrights below.
 *    Modified for LAM by JRV
 *
 * 
 *    We are just putting our stamp on this for housekeeping reasons.
 *
 *    Function    - tstdio internal routines for input formatting
 */

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the University of
 *    California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "lam_config.h"

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)vfscanf.c     5.7 (Berkeley) 12/14/92";
#endif /* LIBC_SCCS and not lint */

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

#include <portable.h>
#include <tstdio.h>

#define FLOATING_POINT

#define     BUF         513   /* Maximum length of numeric string. */

/*
 * JRV: Added these includes, defines and declarations.
 */
extern double           strtod();
extern long       strtol();
#define hardway
#if !__STDC__
#define const
#endif

/*
 * Flags used during conversion.
 */
#define     LONG        0x01  /* l: long or double */
#define     LONGDBL           0x02  /* L: long double; unimplemented */
#define     SHORT       0x04  /* h: short */
#define     SUPPRESS    0x08  /* suppress assignment */
#define     POINTER           0x10  /* weird %p pointer (`fake hex') */
#define     NOSKIP            0x20  /* do not skip blanks */

/*
 * The following are used in numeric conversions only:
 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
 */
#define     SIGNOK            0x40  /* +/- is (still) legal */
#define     NDIGITS           0x80  /* no digits detected */

#define     DPTOK       0x100 /* (float) decimal point is still legal */
#define     EXPOK       0x200 /* (float) exponent (e+3, etc) still legal */

#define     PFXOK       0x100 /* 0x prefix is (still) legal */
#define     NZDIGITS    0x200 /* no zero digits detected */

/*
 * Conversion types.
 */
#define     CT_CHAR           0     /* %c conversion */
#define     CT_CCL            1     /* %[...] conversion */
#define     CT_STRING   2     /* %s conversion */
#define     CT_INT            3     /* integer, i.e., strtol */
#define     CT_FLOAT    4     /* floating, i.e., strtod */

#define u_char unsigned char
#define u_long unsigned long

static u_char *__sccl();

/*
 * vfscanf
 */
int
lam_svfscanf(fp, fmt0, ap)
      register TFILE *fp;
      char const *fmt0;
      va_list ap;
{
      register u_char *fmt = (u_char *)fmt0;
      register int c;         /* character from format, or conversion */
      register size_t width;  /* field width, or 0 */
      register char *p; /* points into all kinds of strings */
      register int n;         /* handy integer */
      register int flags;     /* flags as defined above */
      register char *p0;      /* saves original value of p when necessary */
      int nassigned;          /* number of fields assigned */
      int nread;        /* number of characters consumed from fp */
      int base;         /* base argument to strtol */
      long (*ccfn)();         /* conversion function (strtol) */
      char ccltab[256]; /* character class table for %[...] */
      char buf[BUF];          /* buffer for numeric conversions */
      SIGNED char cin;  /* JRV: character to use for getc */
      int   i;          /* JRV: my favorite loop index */

      /* `basefix' is used to avoid `if' tests in the integer scanner */
      static short basefix[17] =
            { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };

      nassigned = 0;
      nread = 0;
      base = 0;         /* XXX just to keep gcc happy */
      ccfn = NULL;            /* XXX just to keep gcc happy */


/*
 * JRV:  Added priming read.
 */
      cin = tfgetc(fp);

      for (;;) {
            c = *fmt++;
            if (c == 0) {
/* JRV: added next line... */
                  tungetc(cin, fp);
                  return (nassigned);
            }
            if (isspace(c)) {
                  for (;;) {

/* JRV: replaced this junk    if (fp->_r <= 0 && __srefill(fp))
 * with the lines immed.            return (nassigned);
 * following                  if (!isspace(*fp->_p))
 *                            break;
 *                      nread++, fp->_r--, fp->_p++;
 */

/*
 * JRV: Begin replacement
 */
                        if (cin == EOF) {
                              return(nassigned);
                        }
                        if ( !isspace(cin) ) {
                              break;
                        }
                        nread++;
                        cin = tfgetc(fp);
/*
 * JRV: End replacement
 */
                  }
                  continue;
            }
            if (c != '%')
                  goto literal;
            width = 0;
            flags = 0;
            /*
             * switch on the format.  continue if done;
             * break once format type is derived.
             */
again:            c = *fmt++;
            switch (c) {
            case '%':
literal:
/* JRV                  if (fp->_r <= 0 && __srefill(fp))
 *                      goto input_failure;
 *                if (*fp->_p != c)
 *                      goto match_failure;
 *                fp->_r--, fp->_p++;
 *                nread++;
 *                continue;
 */

/*
 * JRV: Begin replacement
 */
                  if (cin == EOF) {
                        goto input_failure;
                  }
                  if (cin != c) {
                        goto match_failure;
                  }
                  cin = tfgetc(fp);
                  nread++;
                  continue;
/*
 * JRV: End replacement
 */
            case '*':
                  flags |= SUPPRESS;
                  goto again;
            case 'l':
                  flags |= LONG;
                  goto again;
            case 'L':
                  flags |= LONGDBL;
                  goto again;
            case 'h':
                  flags |= SHORT;
                  goto again;

            case '0': case '1': case '2': case '3': case '4':
            case '5': case '6': case '7': case '8': case '9':
                  width = width * 10 + c - '0';
                  goto again;

            /*
             * Conversions.
             * Those marked `compat' are for 4.[123]BSD compatibility.
             *
             * (According to ANSI, E and X formats are supposed
             * to the same as e and x.  Sorry about that.)
             */
            case 'D':   /* compat */
                  flags |= LONG;
                  /* FALLTHROUGH */
            case 'd':
                  c = CT_INT;
                  ccfn = strtol;
                  base = 10;
                  break;

            case 'i':
                  c = CT_INT;
                  ccfn = strtol;
                  base = 0;
                  break;

            case 'O':   /* compat */
                  flags |= LONG;
                  /* FALLTHROUGH */
            case 'o':
                  c = CT_INT;
                  ccfn = strtol;
                  base = 8;
                  break;

            case 'u':
                  c = CT_INT;
                  ccfn = strtol;
                  base = 10;
                  break;

            case 'X':   /* compat   XXX */
                  flags |= LONG;
                  /* FALLTHROUGH */
            case 'x':
                  flags |= PFXOK;   /* enable 0x prefixing */
                  c = CT_INT;
                  ccfn = strtol;
                  base = 16;
                  break;

#ifdef FLOATING_POINT
            case 'E':   /* compat   XXX */
            case 'F':   /* compat */
                  flags |= LONG;
                  /* FALLTHROUGH */
            case 'e': case 'f': case 'g':
                  c = CT_FLOAT;
                  break;
#endif

            case 's':
                  c = CT_STRING;
                  break;

            case '[':
                  fmt = __sccl(ccltab, fmt);
                  flags |= NOSKIP;
                  c = CT_CCL;
                  break;

            case 'c':
                  flags |= NOSKIP;
                  c = CT_CHAR;
                  break;

            case 'p':   /* pointer format is like hex */
                  flags |= POINTER | PFXOK;
                  c = CT_INT;
                  ccfn = strtol;
                  base = 16;
                  break;

            case 'n':
                  if (flags & SUPPRESS)   /* ??? */
                        continue;
                  if (flags & SHORT)
                        *va_arg(ap, short *) = nread;
                  else if (flags & LONG)
                        *va_arg(ap, long *) = nread;
                  else
                        *va_arg(ap, int *) = nread;
                  continue;

            /*
             * Disgusting backwards compatibility hacks.    XXX
             */
            case '\0':  /* compat */
                  return (EOF);

            default:    /* compat */
                  if (isupper(c))
                        flags |= LONG;
                  c = CT_INT;
                  ccfn = strtol;
                  base = 10;
                  break;
            }

            /*
             * We have a conversion that requires input.
             */
/* JRV
 *
 *          if (fp->_r <= 0 && __srefill(fp))
 *                goto input_failure;
 */

/*
 * JRV: Begin replacement
 */
            if (cin == EOF) {
                  goto input_failure;
            }
/*
 * JRV: End replacement
 */
            /*
             * Consume leading white space, except for formats
             * that suppress this.
             */
            if ((flags & NOSKIP) == 0) {
/* JRV
 *                while (isspace(*fp->_p)) {
 *                      nread++;
 *                      if (--fp->_r > 0)
 *                            fp->_p++;
 *                      else if (__srefill(fp))
 *                            goto input_failure;
 *                }
 */               /*
                   * Note that there is at least one character in
                   * the buffer, so conversions that do not set NOSKIP
                   * ca no longer result in an input failure.
                   */
/*
 * JRV: Begin replacement
 */
                  while (isspace(cin)) {
                        nread++;
                        cin = tfgetc(fp);
                        if (cin == EOF) {
                              goto input_failure;
                        }
                  }
/*
 * JRV: End replacement
 */
            }

            /*
             * Do the conversion.
             */
            switch (c) {

            case CT_CHAR:
                  /* scan arbitrary characters (sets NOSKIP) */
                  if (width == 0)
                        width = 1;
                  if (flags & SUPPRESS) {
/* JRV                        size_t sum = 0;
 *                      for (;;) {
 *                            if ((n = fp->_r) < width) {
 *                                  sum += n;
 *                                  width -= n;
 *                                  fp->_p += n;
 *                                  if (__srefill(fp)) {
 *                                        if (sum == 0)
 *                                            goto input_failure;
 *                                        break;
 *                                  }
 *                            } else {
 *                                  sum += width;
 *                                  fp->_r -= width;
 *                                  fp->_p += width;
 *                                  break;
 *                            }
 *                      }
 *                      nread += sum;
 */

/*
 * JRV: Begin replacement
 */
                        for(i=0; i<width; i++) {
                              if ((cin = tfgetc(fp)) == EOF) {
                                    goto input_failure;
                              }
                        }
                        nread += width;
/*
 * JRV: End replacement
 */
                  } else {
                        size_t r = tfread((void *)va_arg(ap, char *), 1,
                            width, fp);

                        if (r == 0)
                              goto input_failure;
                        nread += r;
                        nassigned++;
                  }
                  break;

            case CT_CCL:
                  /* scan a (nonempty) character class (sets NOSKIP) */
                  if (width == 0)
                        width = ~0; /* `infinity' */
                  /* take only those things in the class */
                  if (flags & SUPPRESS) {
                        n = 0;

/* JRV                        while (ccltab[*fp->_p]) {
 *                            n++, fp->_r--, fp->_p++;
 *                            if (--width == 0)
 *                                  break;
 *                            if (fp->_r <= 0 && __srefill(fp)) {
 *                                  if (n == 0)
 *                                        goto input_failure;
 *                                  break;
 *                            }
 *                      }
 */

/*
 * JRV: Begin replacement
 */
                        while (ccltab[cin]) {

                              n++;
                              cin = tfgetc(fp);

                              if (--width == 0) {
                                    break;
                              }

                              if (cin == EOF) {
                                    if (n == 0) {
                                          goto input_failure;
                                    }
                                    break;
                              }
                        }
/*
 * JRV: End replacement
 */

                        if (n == 0)
                              goto match_failure;
                  } else {
                        p0 = p = va_arg(ap, char *);

/* JRV                        while (ccltab[*fp->_p]) {
 *                            fp->_r--;
 *                            *p++ = *fp->_p++;
 *                            if (--width == 0)
 *                                  break;
 *                            if (fp->_r <= 0 && __srefill(fp)) {
 *                                  if (p == p0)
 *                                        goto input_failure;
 *                                  break;
 *                            }
 *                      }
 */

/*
 * JRV: Begin replacement
 */

                        while (ccltab[cin]) {
                              *p++ = tfgetc(fp);
                              if (--width == 0) {
                                    break;
                              }
                              if (((SIGNED char) *p) == EOF) {
                                    if (p == p0) {
                                          goto input_failure;
                                    }
                                    break;
                              }
                        }
/*
 * JRV: End replacement
 */
                        n = p - p0;
                        if (n == 0)
                              goto match_failure;
                        *p = 0;
                        nassigned++;
                  }
                  nread += n;
                  break;

            case CT_STRING:
                  /* like CCL, but zero-length string OK, & no NOSKIP */
                  if (width == 0)
                        width = ~0;
                  if (flags & SUPPRESS) {
                        n = 0;

/* JRV                        while (!isspace(*fp->_p)) {
 *                            n++, fp->_r--, fp->_p++;
 *                            if (--width == 0)
 *                                  break;
 *                            if (fp->_r <= 0 && __srefill(fp))
 *                                  break;
 *                      }
 */

/*
 * JRV: Begin replacement
 */

                        while (!isspace(cin)) {
                              n++;
                              cin = tfgetc(fp);
                              if (--width == 0) {
                                    break;
                              }
                              if (cin == EOF) {
                                    break;
                              }
                        }
/*
 * JRV: End replacement
 */

                        nread += n;
                  } else {

                        p0 = p = va_arg(ap, char *);

/* JRV                        while (!isspace(*fp->_p)) {
 *                            fp->_r--;
 *                            *p++ = *fp->_p++;
 *                            if (--width == 0)
 *                                  break;
 *                            if (fp->_r <= 0 && __srefill(fp))
 *                                  break;
 *                      }
 */

/*
 * JRV: Begin replacement
 */
                        while(!isspace(cin)) {
                              *p++ = cin;
                              cin = tfgetc(fp);
                              if (--width == 0) {
                                    break;
                              }
                              if (cin == EOF) {
                                    break;
                              }
                        }
/*
 * JRV: End replacement
 */
                        *p = 0;
                        nread += p - p0;
                        nassigned++;
                  }
                  continue;

            case CT_INT:
                  /* scan an integer as if by strtol */
#ifdef hardway
                  if (width == 0 || width > sizeof(buf) - 1)
                        width = sizeof(buf) - 1;
#else
                  /* size_t is unsigned, hence this optimisation */
                  if (--width > sizeof(buf) - 2)
                        width = sizeof(buf) - 2;
                  width++;
#endif
                  flags |= SIGNOK | NDIGITS | NZDIGITS;
                  for (p = buf; width; width--) {

/* JRV                        c = *fp->_p;
 */

/*
 * JRV: Begin replacement
 */
                        c = cin;
/*
 * JRV: End replacement
 */


                        /*
                         * Switch on the character; `goto ok'
                         * if we accept it as a part of number.
                         */
                        switch (c) {

                        /*
                         * The digit 0 is always legal, but is
                         * special.  For %i conversions, if no
                         * digits (zero or nonzero) have been
                         * scanned (only signs), we will have
                         * base==0.  In that case, we should set
                         * it to 8 and enable 0x prefixing.
                         * Also, if we have not scanned zero digits
                         * before this, do not turn off prefixing
                         * (someone else will turn it off if we
                         * have scanned any nonzero digits).
                         */
                        case '0':
                              if (base == 0) {
                                    base = 8;
                                    flags |= PFXOK;
                              }
                              if (flags & NZDIGITS)
                                  flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
                              else
                                  flags &= ~(SIGNOK|PFXOK|NDIGITS);
                              goto ok;

                        /* 1 through 7 always legal */
                        case '1': case '2': case '3':
                        case '4': case '5': case '6': case '7':
                              base = basefix[base];
                              flags &= ~(SIGNOK | PFXOK | NDIGITS);
                              goto ok;

                        /* digits 8 and 9 ok iff decimal or hex */
                        case '8': case '9':
                              base = basefix[base];
                              if (base <= 8)
                                    break;      /* not legal here */
                              flags &= ~(SIGNOK | PFXOK | NDIGITS);
                              goto ok;

                        /* letters ok iff hex */
                        case 'A': case 'B': case 'C':
                        case 'D': case 'E': case 'F':
                        case 'a': case 'b': case 'c':
                        case 'd': case 'e': case 'f':
                              /* no need to fix base here */
                              if (base <= 10)
                                    break;      /* not legal here */
                              flags &= ~(SIGNOK | PFXOK | NDIGITS);
                              goto ok;

                        /* sign ok only as first character */
                        case '+': case '-':
                              if (flags & SIGNOK) {
                                    flags &= ~SIGNOK;
                                    goto ok;
                              }
                              break;

                        /* x ok iff flag still set & 2nd char */
                        case 'x': case 'X':
                              if (flags & PFXOK && p == buf + 1) {
                                    base = 16;  /* if %i */
                                    flags &= ~PFXOK;
                                    goto ok;
                              }
                              break;
                        }

                        /*
                         * If we got here, c is not a legal character
                         * for a number.  Stop accumulating digits.
                         */
                        break;
            ok:
                        /*
                         * c is legal: store it and look at the next.
                         */
                        *p++ = c;

/* JRV                        if (--fp->_r > 0)
 *                            fp->_p++;
 *                      else if (__srefill(fp))
 *                            break;            
 */                                       /* EOF */


/*
 * JRV: Begin replacement
 */
                        cin = tfgetc(fp);
                        if (cin == EOF) {
                              break;
                        }
/*
 * JRV: End replacement
 */

                  }
                  /*
                   * If we had only a sign, it is no good; push
                   * back the sign.  If the number ends in `x',
                   * it was [sign] '0' 'x', so push back the x
                   * and treat it as [sign] '0'.
                   */
                  if (flags & NDIGITS) {
                        if (p > buf)
                              (void) tungetc(*(u_char *)--p, fp);
                        goto match_failure;
                  }
                  c = ((u_char *)p)[-1];
                  if (c == 'x' || c == 'X') {
                        --p;
                        (void) tungetc(c, fp);
                  }
                  if ((flags & SUPPRESS) == 0) {
                        u_long res;

                        *p = 0;
                        res = (*ccfn)(buf, (char **)NULL, base);
                        if (flags & POINTER)
                              *va_arg(ap, void **) = (void *)res;
                        else if (flags & SHORT)
                              *va_arg(ap, short *) = res;
                        else if (flags & LONG)
                              *va_arg(ap, long *) = res;
                        else
                              *va_arg(ap, int *) = res;
                        nassigned++;
                  }
                  nread += p - buf;
                  break;

#ifdef FLOATING_POINT
            case CT_FLOAT:
                  /* scan a floating point number as if by strtod */
#ifdef hardway
                  if (width == 0 || width > sizeof(buf) - 1)
                        width = sizeof(buf) - 1;
#else
                  /* size_t is unsigned, hence this optimisation */
                  if (--width > sizeof(buf) - 2)
                        width = sizeof(buf) - 2;
                  width++;
#endif
                  flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
                  for (p = buf; width; width--) {

/* JRV                        c = *fp->_p;
 */

/*
 * JRV: Begin replacement
 */
                        c = cin;
/*
 * JRV: End replacement
 */

                        /*
                         * This code mimicks the integer conversion
                         * code, but is much simpler.
                         */
                        switch (c) {

                        case '0': case '1': case '2': case '3':
                        case '4': case '5': case '6': case '7':
                        case '8': case '9':
                              flags &= ~(SIGNOK | NDIGITS);
                              goto fok;

                        case '+': case '-':
                              if (flags & SIGNOK) {
                                    flags &= ~SIGNOK;
                                    goto fok;
                              }
                              break;
                        case '.':
                              if (flags & DPTOK) {
                                    flags &= ~(SIGNOK | DPTOK);
                                    goto fok;
                              }
                              break;
                        case 'e': case 'E':
                              /* no exponent without some digits */
                              if ((flags&(NDIGITS|EXPOK)) == EXPOK) {
                                    flags =
                                        (flags & ~(EXPOK|DPTOK)) |
                                        SIGNOK | NDIGITS;
                                    goto fok;
                              }
                              break;
                        }
                        break;
            fok:
                        *p++ = c;

/* JRV                        if (--fp->_r > 0)
 *                            fp->_p++;
 *                      else if (__srefill(fp))
 *                            break;
 */                                 /* EOF */

/*
 * JRV: End replacement
 */
                        cin = tfgetc(fp);
                        if (cin == EOF) {
                              break;
                        }
/*
 * JRV: End replacement
 */

                  }
                  /*
                   * If no digits, might be missing exponent digits
                   * (just give back the exponent) or might be missing
                   * regular digits, but had sign and/or decimal point.
                   */
                  if (flags & NDIGITS) {
                        if (flags & EXPOK) {
                              /* no digits at all */
                              while (p > buf)
                                    tungetc(*(u_char *)--p, fp);
                              goto match_failure;
                        }
                        /* just a bad exponent (e and maybe sign) */
                        c = *(u_char *)--p;
                        if (c != 'e' && c != 'E') {
                              (void) tungetc(c, fp);/* sign */
                              c = *(u_char *)--p;
                        }
                        (void) tungetc(c, fp);
                  }
                  if ((flags & SUPPRESS) == 0) {
                        double res;

                        *p = 0;
                        res = strtod(buf,(char **) NULL);
                        if (flags & LONG)
                              *va_arg(ap, double *) = res;
                        else
                              *va_arg(ap, float *) = res;
                        nassigned++;
                  }
                  nread += p - buf;
                  break;
#endif /* FLOATING_POINT */
            }
      }
input_failure:
      return (nassigned ? nassigned : -1);
match_failure:
      return (nassigned);
}

/*
 * Fill in the given table from the scanset at the given format
 * (just after `[').  Return a pointer to the character past the
 * closing `]'.  The table has a 1 wherever characters should be
 * considered part of the scanset.
 */
static u_char *
__sccl(tab, fmt)
      register char *tab;
      register u_char *fmt;
{
      register int c, n, v;

      /* first `clear' the whole table */
      c = *fmt++;       /* first char hat => negated scanset */
      if (c == '^') {
            v = 1;            /* default => accept */
            c = *fmt++; /* get new first char */
      } else
            v = 0;            /* default => reject */
      /* should probably use memset here */
      for (n = 0; n < 256; n++)
            tab[n] = v;
      if (c == 0)
            return (fmt - 1);/* format ended before closing ] */

      /*
       * Now set the entries corresponding to the actual scanset
       * to the opposite of the above.
       *
       * The first character may be ']' (or '-') without being special;
       * the last character may be '-'.
       */
      v = 1 - v;
      for (;;) {
            tab[c] = v;       /* take character c */
doswitch:
            n = *fmt++;       /* and examine the next */
            switch (n) {

            case 0:                 /* format ended too soon */
                  return (fmt - 1);

            case '-':
                  /*
                   * A scanset of the form
                   *    [01+-]
                   * is defined as `the digit 0, the digit 1,
                   * the character +, the character -', but
                   * the effect of a scanset such as
                   *    [a-zA-Z0-9]
                   * is implementation defined.  The V7 Unix
                   * scanf treats `a-z' as `the letters a through
                   * z', but treats `a-a' as `the letter a, the
                   * character -, and the letter a'.
                   *
                   * For compatibility, the `-' is not considerd
                   * to define a range if the character following
                   * it is either a close bracket (required by ANSI)
                   * or is not numerically greater than the character
                   * we just stored in the table (c).
                   */
                  n = *fmt;
                  if (n == ']' || n < c) {
                        c = '-';
                        break;      /* resume the for(;;) */
                  }
                  fmt++;
                  do {        /* fill in the range */
                        tab[++c] = v;
                  } while (c < n);
#if 1 /* XXX another disgusting compatibility hack */
                  /*
                   * Alas, the V7 Unix scanf also treats formats
                   * such as [a-c-e] as `the letters a through e'.
                   * This too is permitted by the standard....
                   */
                  goto doswitch;
#else
                  c = *fmt++;
                  if (c == 0)
                        return (fmt - 1);
                  if (c == ']')
                        return (fmt);
                  break;
#endif

            case ']':         /* end of scanset */
                  return (fmt);

            default:          /* just another character */
                  c = n;
                  break;
            }
      }
      /* NOTREACHED */
}

#if 0
vscanf(fmt, ap)
      const char *fmt;
      _VA_LIST_ ap;
{

      return (lam_svfscanf(tstdin, fmt, ap));
}

static int
eofread(cookie, buf, len)
      void *cookie;
      char *buf;
      int len;
{

      return (0);
}

vsscanf(str, fmt, ap)
      const char *str;
      const char *fmt;
      _VA_LIST_ ap;
{
      int ret;
      TFILE f;

      f._flags = __SRD;
      f._bf._base = f._p = (unsigned char *)str;
      f._bf._size = f._r = strlen(str);
      f._read = eofread;
      f._ub._base = NULL;
      f._lb._base = NULL;
      return (lam_svfscanf(&f, fmt, ap));
}
#endif

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