reactos/lib/sdk/crt/stdlib/wcstoul.c

   1 /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
   2 #include <precomp.h>
   3
   4 /*
   5  * Convert a unicode string to an unsigned long integer.
   6  *
   7  * Ignores `locale' stuff.  Assumes that the upper and lower case
   8  * alphabets and digits are each contiguous.
   9  *
  10  * @implemented
  11  */
  12 unsigned long
  13 wcstoul(const wchar_t *nptr, wchar_t **endptr, int base)
  14 {
  15   const wchar_t *s = nptr;
  16   unsigned long acc;
  17   int c;
  18   unsigned long cutoff;
  19   int neg = 0, any, cutlim;
  20
  21   /*
  22    * See strtol for comments as to the logic used.
  23    */
  24   do {
  25     c = *s++;
  26   } while (iswspace(c));
  27   if (c == L'-')
  28   {
  29     neg = 1;
  30     c = *s++;
  31   }
  32   else if (c == L'+')
  33     c = *s++;
  34   if ((base == 0 || base == 16) &&
  35       c == L'0' && (*s == L'x' || *s == L'X'))
  36   {
  37     c = s[1];
  38     s += 2;
  39     base = 16;
  40   }
  41   if (base == 0)
  42     base = c == L'0' ? 8 : 10;
  43   cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
  44   cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
  45   for (acc = 0, any = 0;; c = *s++)
  46   {
  47     if (iswdigit(c))
  48       c -= L'0';
  49     else if (iswalpha(c))
  50       c -= iswupper(c) ? L'A' - 10 : L'a' - 10;
  51     else
  52       break;
  53     if (c >= base)
  54       break;
  55     if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
  56       any = -1;
  57     else {
  58       any = 1;
  59       acc *= base;
  60       acc += c;
  61     }
  62   }
  63   if (any < 0)
  64   {
  65     acc = ULONG_MAX;
  66     __set_errno(ERANGE);
  67   }
  68   else if (neg)
  69     acc = -acc;
  70   if (endptr != 0)
  71     *endptr = any ? (wchar_t *)s - 1 : (wchar_t *)nptr;
  72   return acc;
  73 }
  74
  75 #if 0
  76 unsigned long wcstoul(const wchar_t *cp,wchar_t **endp,int base)
  77 {
  78         unsigned long result = 0,value;
  79
  80         if (!base) {
  81                 base = 10;
  82                 if (*cp == L'0') {
  83                         base = 8;
  84                         cp++;
  85                         if ((*cp == L'x') && iswxdigit(cp[1])) {
  86                                 cp++;
  87                                 base = 16;
  88                         }
  89                 }
  90         }
  91         while (iswxdigit(*cp) && (value = iswdigit(*cp) ? *cp-L'0' : (iswlower(*cp)
  92             ? towupper(*cp) : *cp)-L'A'+10) < base) {
  93                 result = result*base + value;
  94                 cp++;
  95         }
  96         if (endp)
  97                 *endp = (wchar_t *)cp;
  98         return result;
  99 }
 100 #endif