IPアドレスからホスト名を得る
struct HOSTENT* FAR gethostbyaddr(
const char* addr,
int len,
int type
);
addr
- A pointer to an address in network byte order.
len
- The length of the address, which must be 4 for PF_INET addresses.
type
- The type of the address, which must be PF_INET.