The strings are compared until a null character is encountered,
    the strings differ, or maxchar is reached. If characters differ,
    wcsncmp returns:

    o  An integer less than 0 if the codepoint of the first differing
       character in wstr_1 is less than the codepoint of the
       corresponding character in wstr_2

    o  An integer greater than 0 if the codepoint of the first
       differing character in wstr_1 is greater than the codepoint
       of the corresponding character in wstr_2

    If no differences are found after comparing maxchar characters,
    the function returns 0.

    See also wcscmp.