问iOS模拟器中的Basic套接字编程

EN

    int status;
    struct addrinfo hints;
    struct addrinfo *servinfo;
    char ipstr[INET6_ADDRSTRLEN];

    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags = AI_PASSIVE;

    if ((status = getaddrinfo("www.yahoo.com", 
                              "80", 
                              &hints, 
                              &servinfo)) != 0) {
        fprintf(stderr, "getaddrinfo error: %s\n", gai_strerror(status));
        exit(1);
    }

    for(struct addrinfo *p = servinfo; p != NULL; p = p->ai_next) {
        void *addr;
        char *ipver;

        if (p->ai_family == AF_INET) {
            struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;
            addr = &(ipv4->sin_addr);
            ipver = "IPv4";
        } else {
            struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)p->ai_addr;
            addr = &(ipv6->sin6_addr);
            ipver = "IPv6";
        }

        inet_ntop(p->ai_family, addr, ipstr, sizeof(ipstr));
        printf("  %s: %s\n", ipver, ipstr);

        int socketfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
        if (socketfd)
            printf("errno: %d\n", errno);
    }

    freeaddrinfo(servinfo);

  IPv4: 72.30.38.140
  errno: 2
  IPv4: 72.30.2.43
  errno: 2