wcsspn

   Compares the characters in a wide-character string against a set
   of wide characters. The function returns the length of the first
   substring comprised entirely of characters in the set of wide
   characters.

   Format

     #include  <wchar.h>

     size_t wcsspn  (const wchar_t *wstr1, const wchar_t *wstr2);
 

Additional information available:

Arguments       Description     Return_Value    Example