wchar_t *wcsnchr(const wchar_t *str,
                 size_t n,
                 wchar_t ch);

wcsnchr searches not more than n wide characters to locate the first occurrence of c in the wide string pointed to by s. The terminating wide null character is considered to be part of the wide string.

wcsnchr returns a pointer to the located wide character, or a null pointer if c does not occur in the string.