Getnameinfo Function

Input
sockaddr, type of output
Output
hostname or IPv4/v6 address
service name or number
int getnameinfo(sa, salen, host, hlen, port,
        plen, flags)
    const struct sockaddr *sa;
    socklen_t salen;
    char *host;
    size_t hlen;
    char *port;
    size_t plen;
    int flags;