The wcsstr() function is the wide-character equivalent of
the strstr(3) function. It searches for the first occurrence of the
wide-character string needle (without its terminating null wide
character (L'\0')) as a substring in the wide-character string
haystack.
RETURN VALUE
The wcsstr() function returns a pointer to the first
occurrence of needle in haystack. It returns NULL if
needle does not occur as a substring in haystack.
Note the special case: If needle is the empty
wide-character string, the return value is always haystack
itself.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).