int in_addr_from_string(unsigned family, const char *s, union in_addr_union *ret);
int in_addr_from_string_auto(const char *s, unsigned *family, union in_addr_union *ret);
int in_addr_from_string(unsigned family, const char *s, union in_addr_union *ret);
int in_addr_from_string_auto(const char *s, unsigned *family, union in_addr_union *ret);