wcscasecmp() is the wide-character equivalent of strcasecmp(). It compares the wide-character string s1 and the wide-character string s2, ignoring case differences (towupper, towlower).
The wcscasecmp() function shall return 0 if the wide-character strings s1 and s2 are equal except for case distinctions. It shall return a positive integer if s1 is greater than s2, ignoring case. It shall return a negative integer if s1 is less than s2, ignoring case.