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newlib-cygwin/newlib/libc/stdio/vfscanf.c

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/*
FUNCTION
<<vscanf>>, <<vfscanf>>, <<vsscanf>>---format argument list
INDEX
vscanf
INDEX
vfscanf
INDEX
vsscanf
ANSI_SYNOPSIS
#include <stdio.h>
#include <stdarg.h>
int vscanf(const char *<[fmt]>, va_list <[list]>);
int vfscanf(FILE *<[fp]>, const char *<[fmt]>, va_list <[list]>);
int vsscanf(const char *<[str]>, const char *<[fmt]>, va_list <[list]>);
int _vscanf_r(void *<[reent]>, const char *<[fmt]>,
va_list <[list]>);
int _vfscanf_r(void *<[reent]>, FILE *<[fp]>, const char *<[fmt]>,
va_list <[list]>);
int _vsscanf_r(void *<[reent]>, const char *<[str]>, const char *<[fmt]>,
va_list <[list]>);
TRAD_SYNOPSIS
#include <stdio.h>
#include <varargs.h>
int vscanf( <[fmt]>, <[ist]>)
char *<[fmt]>;
va_list <[list]>;
int vfscanf( <[fp]>, <[fmt]>, <[list]>)
FILE *<[fp]>;
char *<[fmt]>;
va_list <[list]>;
int vsscanf( <[str]>, <[fmt]>, <[list]>)
char *<[str]>;
char *<[fmt]>;
va_list <[list]>;
int _vscanf_r( <[reent]>, <[fmt]>, <[ist]>)
char *<[reent]>;
char *<[fmt]>;
va_list <[list]>;
int _vfscanf_r( <[reent]>, <[fp]>, <[fmt]>, <[list]>)
char *<[reent]>;
FILE *<[fp]>;
char *<[fmt]>;
va_list <[list]>;
int _vsscanf_r( <[reent]>, <[str]>, <[fmt]>, <[list]>)
char *<[reent]>;
char *<[str]>;
char *<[fmt]>;
va_list <[list]>;
DESCRIPTION
<<vscanf>>, <<vfscanf>>, and <<vsscanf>> are (respectively) variants
of <<scanf>>, <<fscanf>>, and <<sscanf>>. They differ only in
allowing their caller to pass the variable argument list as a
<<va_list>> object (initialized by <<va_start>>) rather than
directly accepting a variable number of arguments.
RETURNS
The return values are consistent with the corresponding functions:
<<vscanf>> returns the number of input fields successfully scanned,
converted, and stored; the return value does not include scanned
fields which were not stored.
If <<vscanf>> attempts to read at end-of-file, the return value
is <<EOF>>.
If no fields were stored, the return value is <<0>>.
The routines <<_vscanf_r>>, <<_vfscanf_f>>, and <<_vsscanf_r>> are
reentrant versions which take an additional first parameter which points to the
reentrancy structure.
PORTABILITY
These are GNU extensions.
Supporting OS subroutines required:
*/
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include <_ansi.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <wchar.h>
#include <string.h>
#ifdef _HAVE_STDC
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include "local.h"
#ifndef NO_FLOATING_POINT
#define FLOATING_POINT
#endif
#ifdef FLOATING_POINT
#include <float.h>
/* Currently a test is made to see if long double processing is warranted.
This could be changed in the future should the _ldtoa_r code be
preferred over _dtoa_r. */
#define _NO_LONGDBL
#if defined WANT_IO_LONG_DBL && (LDBL_MANT_DIG > DBL_MANT_DIG)
#undef _NO_LONGDBL
extern _LONG_DOUBLE _strtold _PARAMS((char *s, char **sptr));
#endif
#define _NO_LONGLONG
#if defined WANT_PRINTF_LONG_LONG && defined __GNUC__
# undef _NO_LONGLONG
#endif
#include "floatio.h"
#define BUF (MAXEXP+MAXFRACT+3) /* 3 = sign + decimal point + NUL */
/* An upper bound for how long a long prints in decimal. 4 / 13 approximates
log (2). Add one char for roundoff compensation and one for the sign. */
#define MAX_LONG_LEN ((CHAR_BIT * sizeof (long) - 1) * 4 / 13 + 2)
#else
#define BUF 40
#endif
/*
* Flags used during conversion.
*/
#define LONG 0x01 /* l: long or double */
#define LONGDBL 0x02 /* L: long double or long long */
#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 or strtoul */
#define CT_FLOAT 4 /* floating, i.e., strtod */
#if 0
#define u_char unsigned char
#endif
#define u_char char
#define u_long unsigned long
#ifndef _NO_LONGLONG
typedef unsigned long long u_long_long;
#endif
/*static*/ u_char *__sccl ();
/*
* vfscanf
*/
#define BufferEmpty (fp->_r <= 0 && __srefill(fp))
#ifndef _REENT_ONLY
int
_DEFUN (vfscanf, (fp, fmt, ap),
register FILE *fp _AND
_CONST char *fmt _AND
va_list ap)
{
CHECK_INIT(fp);
return __svfscanf_r (fp->_data, fp, fmt, ap);
}
int
__svfscanf (fp, fmt0, ap)
register FILE *fp;
char _CONST *fmt0;
va_list ap;
{
return __svfscanf_r (_REENT, fp, fmt0, ap);
}
#endif /* !_REENT_ONLY */
int
_DEFUN (_vfscanf_r, (data, fp, fmt, ap),
struct _reent *data _AND
register FILE *fp _AND
_CONST char *fmt _AND
va_list ap)
{
return __svfscanf_r (data, fp, fmt, ap);
}
int
__svfscanf_r (rptr, fp, fmt0, ap)
struct _reent *rptr;
register FILE *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 = 0; /* base argument to strtol/strtoul */
int nbytes = 1; /* number of bytes read from fmt string */
wchar_t wc; /* wchar to use to read format string */
u_long (*ccfn) () = 0; /* conversion function (strtol/strtoul) */
char ccltab[256]; /* character class table for %[...] */
char buf[BUF]; /* buffer for numeric conversions */
char *lptr; /* literal pointer */
#ifdef MB_CAPABLE
mbstate_t state; /* value to keep track of multibyte state */
#endif
short *sp;
int *ip;
float *flp;
_LONG_DOUBLE *ldp;
double *dp;
long *lp;
#ifndef _NO_LONGLONG
long long *llp;
#else
u_long _uquad;
#endif
/* `basefix' is used to avoid `if' tests in the integer scanner */
static _CONST short basefix[17] =
{10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
nassigned = 0;
nread = 0;
for (;;)
{
#ifndef MB_CAPABLE
wc = *fmt;
#else
memset (&state, '\0', sizeof (state));
nbytes = _mbtowc_r (rptr, &wc, fmt, MB_CUR_MAX, &state);
#endif
fmt += nbytes;
if (wc == 0)
return nassigned;
if (nbytes == 1 && isspace (wc))
{
for (;;)
{
if (BufferEmpty || !isspace (*fp->_p))
break;
nread++, fp->_r--, fp->_p++;
}
continue;
}
if (wc != '%')
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:
lptr = fmt - nbytes;
for (n = 0; n < nbytes; ++n)
{
if (BufferEmpty)
goto input_failure;
if (*fp->_p != *lptr)
goto match_failure;
fp->_r--, fp->_p++;
nread++;
++lptr;
}
continue;
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 = (u_long (*)())_strtol_r;
base = 10;
break;
case 'i':
c = CT_INT;
ccfn = (u_long (*)())_strtol_r;
base = 0;
break;
case 'O': /* compat */
flags |= LONG;
/* FALLTHROUGH */
case 'o':
c = CT_INT;
ccfn = _strtoul_r;
base = 8;
break;
case 'u':
c = CT_INT;
ccfn = _strtoul_r;
base = 10;
break;
case 'X': /* compat XXX */
case 'x':
flags |= PFXOK; /* enable 0x prefixing */
c = CT_INT;
ccfn = _strtoul_r;
base = 16;
break;
#ifdef FLOATING_POINT
case 'E': /* compat XXX */
case 'G': /* compat XXX */
/* ANSI says that E,G and X behave the same way as e,g,x */
/* 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 = _strtoul_r;
base = 16;
break;
case 'n':
if (flags & SUPPRESS) /* ??? */
continue;
if (flags & SHORT)
{
sp = va_arg (ap, short *);
*sp = nread;
}
else if (flags & LONG)
{
lp = va_arg (ap, long *);
*lp = nread;
}
#ifndef _NO_LONGLONG
else if (flags & LONGDBL)
{
llp = va_arg (ap, long long*);
*llp = nread;
}
#endif
else
{
ip = va_arg (ap, int *);
*ip = nread;
}
continue;
/*
* Disgusting backwards compatibility hacks. XXX
*/
case '\0': /* compat */
return EOF;
default: /* compat */
if (isupper (c))
flags |= LONG;
c = CT_INT;
ccfn = (u_long (*)())_strtol_r;
base = 10;
break;
}
/*
* We have a conversion that requires input.
*/
if (BufferEmpty)
goto input_failure;
/*
* Consume leading white space, except for formats that
* suppress this.
*/
if ((flags & NOSKIP) == 0)
{
while (isspace (*fp->_p))
{
nread++;
if (--fp->_r > 0)
fp->_p++;
else
#ifndef CYGNUS_NEC
if (__srefill (fp))
#endif
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.
*/
}
/*
* Do the conversion.
*/
switch (c)
{
case CT_CHAR:
/* scan arbitrary characters (sets NOSKIP) */
if (width == 0)
width = 1;
if (flags & SUPPRESS)
{
size_t sum = 0;
for (;;)
{
if ((n = fp->_r) < (int)width)
{
sum += n;
width -= n;
fp->_p += n;
#ifndef CYGNUS_NEC
if (__srefill (fp))
{
#endif
if (sum == 0)
goto input_failure;
break;
#ifndef CYGNUS_NEC
}
#endif
}
else
{
sum += width;
fp->_r -= width;
fp->_p += width;
break;
}
}
nread += sum;
}
else
{
#ifdef CYGNUS_NEC
/* Kludge city for the moment */
char *dest = va_arg (ap, char *);
int n = width;
if (fp->_r == 0)
goto input_failure;
while (n && fp->_r)
{
*dest++ = *(fp->_p++);
n--;
fp->_r--;
nread++;
}
#else
size_t r = fread ((_PTR) va_arg (ap, char *), 1, width, fp);
if (r == 0)
goto input_failure;
nread += r;
#endif
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;
while (ccltab[*fp->_p])
{
n++, fp->_r--, fp->_p++;
if (--width == 0)
break;
if (BufferEmpty)
{
if (n == 0)
goto input_failure;
break;
}
}
if (n == 0)
goto match_failure;
}
else
{
p0 = p = va_arg (ap, char *);
while (ccltab[*fp->_p])
{
fp->_r--;
*p++ = *fp->_p++;
if (--width == 0)
break;
if (BufferEmpty)
{
if (p == p0)
goto input_failure;
break;
}
}
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;
while (!isspace (*fp->_p))
{
n++, fp->_r--, fp->_p++;
if (--width == 0)
break;
if (BufferEmpty)
break;
}
nread += n;
}
else
{
p0 = p = va_arg (ap, char *);
while (!isspace (*fp->_p))
{
fp->_r--;
*p++ = *fp->_p++;
if (--width == 0)
break;
if (BufferEmpty)
break;
}
*p = 0;
nread += p - p0;
nassigned++;
}
continue;
case CT_INT:
/* scan an integer as if by strtol/strtoul */
#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--)
{
c = *fp->_p;
/*
* 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;
if (--fp->_r > 0)
fp->_p++;
else
#ifndef CYGNUS_NEC
if (__srefill (fp))
#endif
break; /* EOF */
}
/*
* 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)
_CAST_VOID ungetc (*(u_char *)-- p, fp);
goto match_failure;
}
c = ((u_char *) p)[-1];
if (c == 'x' || c == 'X')
{
--p;
/*(void)*/ ungetc (c, fp);
}
if ((flags & SUPPRESS) == 0)
{
u_long res;
*p = 0;
res = (*ccfn) (rptr, buf, (char **) NULL, base);
if (flags & POINTER)
*(va_arg (ap, _PTR *)) = (_PTR) (unsigned _POINTER_INT) res;
else if (flags & SHORT)
{
sp = va_arg (ap, short *);
*sp = res;
}
else if (flags & LONG)
{
lp = va_arg (ap, long *);
*lp = res;
}
#ifndef _NO_LONGLONG
else if (flags & LONGDBL)
{
u_long_long resll;
if (ccfn == _strtoul_r)
resll = _strtoull_r (rptr, buf, (char **) NULL, base);
else
resll = _strtoll_r (rptr, buf, (char **) NULL, base);
llp = va_arg (ap, long long*);
*llp = resll;
}
#endif
else
{
ip = va_arg (ap, int *);
*ip = res;
}
nassigned++;
}
nread += p - buf;
break;
#ifdef FLOATING_POINT
case CT_FLOAT:
{
/* scan a floating point number as if by strtod */
/* This code used to assume that the number of digits is reasonable.
However, ANSI / ISO C makes no such stipulation; we have to get
exact results even when there is an unreasonable amount of
leading zeroes. */
long leading_zeroes = 0;
long zeroes, exp_adjust;
char *exp_start = NULL;
#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;
zeroes = 0;
exp_adjust = 0;
for (p = buf; width; )
{
c = *fp->_p;
/*
* This code mimicks the integer conversion
* code, but is much simpler.
*/
switch (c)
{
case '0':
if (flags & NDIGITS)
{
flags &= ~SIGNOK;
zeroes++;
goto fskip;
}
/* Fall through. */
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);
leading_zeroes = zeroes;
goto fok;
}
break;
case 'e':
case 'E':
/* no exponent without some digits */
if ((flags & (NDIGITS | EXPOK)) == EXPOK
|| ((flags & EXPOK) && zeroes))
{
if (! (flags & DPTOK))
{
exp_adjust = zeroes - leading_zeroes;
exp_start = p;
}
flags =
(flags & ~(EXPOK | DPTOK)) |
SIGNOK | NDIGITS;
zeroes = 0;
goto fok;
}
break;
}
break;
fok:
*p++ = c;
width--;
fskip:
++nread;
if (--fp->_r > 0)
fp->_p++;
else
#ifndef CYGNUS_NEC
if (__srefill (fp))
#endif
break; /* EOF */
}
if (zeroes)
flags &= ~NDIGITS;
/*
* 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)
{
ungetc (*(u_char *)-- p, fp);
--nread;
}
goto match_failure;
}
/* just a bad exponent (e and maybe sign) */
c = *(u_char *)-- p;
--nread;
if (c != 'e' && c != 'E')
{
_CAST_VOID ungetc (c, fp); /* sign */
c = *(u_char *)-- p;
--nread;
}
_CAST_VOID ungetc (c, fp);
}
if ((flags & SUPPRESS) == 0)
{
#ifdef _NO_LONGDBL
double res;
#else /* !_NO_LONG_DBL */
long double res;
#endif /* !_NO_LONG_DBL */
long new_exp = 0;
*p = 0;
if ((flags & (DPTOK | EXPOK)) == EXPOK)
{
exp_adjust = zeroes - leading_zeroes;
new_exp = -exp_adjust;
exp_start = p;
}
else if (exp_adjust)
new_exp = _strtol_r (rptr, (exp_start + 1), NULL, 10) - exp_adjust;
if (exp_adjust)
{
/* If there might not be enough space for the new exponent,
truncate some trailing digits to make room. */
if (exp_start >= buf + sizeof (buf) - MAX_LONG_LEN)
exp_start = buf + sizeof (buf) - MAX_LONG_LEN - 1;
sprintf (exp_start, "e%ld", new_exp);
}
#ifdef _NO_LONGDBL
res = _strtod_r (rptr, buf, NULL);
#else /* !_NO_LONGDBL */
res = _strtold (buf, NULL);
#endif /* !_NO_LONGDBL */
if (flags & LONG)
{
dp = va_arg (ap, double *);
*dp = res;
}
else if (flags & LONGDBL)
{
ldp = va_arg (ap, _LONG_DOUBLE *);
*ldp = res;
}
else
{
flp = va_arg (ap, float *);
*flp = res;
}
nassigned++;
}
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;
#endif
break;
case ']': /* end of scanset */
return fmt;
default: /* just another character */
c = n;
break;
}
}
/* NOTREACHED */
}
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