strncasecmp_l
int strncasecmp_l(const char *, const char *, size_t, locale_t);
extern int strncasecmp_l(const char *, const char *, size_t, locale_t);
extern int strncasecmp_l(const char *, const char *, size_t, locale_t);
return (strncasecmp_l(s1, s2, n, uselocale(NULL)));