reactos/lib/msvcrt/stdlib/wcstoul.c

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