reactos/lib/ntdll/stdlib/wtoi64.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            lib/ntdll/stdlib/wtoi64.c
   6  * PURPOSE:         converts a unicode string to 64 bit integer
   7  */
   8
   9 #include <stdlib.h>
  10 #include <ctype.h>
  11
  12 /*
  13  * @implemented
  14  */
  15 __int64
  16 _wtoi64 (const wchar_t *nptr)
  17 {
  18    int c;
  19    __int64 value;
  20    int sign;
  21
  22    while (iswctype((int)*nptr, _SPACE))
  23         ++nptr;
  24
  25    c = (int)*nptr++;
  26    sign = c;
  27    if (c == L'-' || c == L'+')
  28         c = (int)*nptr++;
  29
  30    value = 0;
  31
  32    while (iswctype(c, _DIGIT))
  33      {
  34         value = 10 * value + (c - L'0');
  35         c = (int)*nptr++;
  36      }
  37
  38    if (sign == L'-')
  39        return -value;
  40    else
  41        return value;
  42 }
  43
  44 /* EOF */