struct hostent *gethostbyaddr(const void *addr,
                                     socklen_t len, int type);

The gethostbyaddr() function returns a structure of type hostent for the given host address addr of length len and type type.  Valid address types are AF_INET and AF_INET6.  The host address argument is  a  pointer  to struct a of  a  type depending on the address type, for example a struct in_addr * (probably obtained via a call to inet_addr(3)) for address type AF_INET.

Les italiques sont de moi. Bon bein pour réimplémenter le bousin, je sens que ça va être fun...