Converts a wide string into an unsigned long (or unsigned long long) integer value
#include <wchar.h> unsigned long int wcstoul ( const wchar_t * restrict wcs , wchar_t ** restrict endptr , int base ); unsigned long long int wcstoull ( const wchar_t * restrict wcs , wchar_t ** restrict endptr , int base ); (C99)
The wcstoul( ) function attempts to interpret the wide string addressed by its first pointer argument, wcs, as an integer numeric value, and returns the result with the type unsigned long. wcstoull( ) is similar, but returns unsigned long long. These functions are the wide-string equivalents of strtoul( ) and strtoull( ), and they work in the same way, except that they operate on strings of wchar_t rather than char. See the description for strtol( ) in this chapter.
If the resulting value is outside the range of the function's type, then the return value is ULONG_MAX, depending on the sign (or ULLONG_MAX, for wcstoull( )), and the errno variable is set to the value of ERANGE ("range error").
See the example for the analogous function wcstol( ) in this chapter.
wcstol( ), wcstod( ), wcstof( ), and wcstold( ); strtol( ) and strtoul( )