wcscasecmp - compare two wide-character strings, ignoring case
s1, const wchar_t *s2);
The wcscasecmp function is the wide-character
equivalent of the strcasecmp function. It compares
the wide-character string pointed to by s1 and the
wide-character string pointed to by s2, ignoring case
differences (towupper, towlower).
The wcscasecmp function returns zero if the
wide-character strings at s1 and s2 are equal
except for case distinctions. It returns a positive integer
if s1 is greater than s2, ignoring case. It
returns a negative integer if s1 is smaller than
s2, ignoring case.
This function is a GNU extension.
The behaviour of wcscasecmp depends on the LC_CTYPE
category of the current locale.