UDP 服务器与多个客户端通信

服务端与多个客户端进行连接，接收客户端发送来的信息。通信端口5000

服务端：IP设置为196.168.1.100

 　　int sock_fd = socket(PF_INET, SOCK_DGRAM, 0);

    if (sock_fd < 0)
    {
        printf ( "error: Create Socket Failed!" );
        return  -1;
    }

    struct  sockaddr_in sock_addr;
    sock_addr.sin_family = AF_INET;
    sock_addr.sin_port = htons(5000);
    sock_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    memset (sock_addr.sin_zero, 0x00, 8);

    try
    {
        if (bind(sock_fd, ( struct  sockaddr *)&sock_addr, sizeof ( struct  sockaddr)) != 0)   //绑定
        {
            printf ( "error: Bind Socket Failed!" );
            res = -1;
            throw  res;
        }

        char  buf[256];
        int  recvslen;
        struct  sockaddr_in from;
        uint32_t fromlen = sizeof(struct sockaddr);
        while (1)
        {
            if ((recvslen = recvfrom(sock_fd, recvs, 256, 0, ( struct  sockaddr *)&from , &fromlen)) == -1)
            {
                printf ( "error: Receiving Failed!" );
                res = -1;
                throw  res;
            }
            else
            {
                if (recvslen < 256)
                    *(recvs+recvslen) = '\0' ;
                else
                    *(recvs+255) = '\0' ;
　　　　　　　　if (from.sin_addr.s_addr == inet_addr(196.168.1.2)){      //根据from的IP地址来确定是接收的哪个IP发来的信息
                　　 printf ( "Received data:\n[%s] from 196.168.1.2\n" ,recvs);
　　　　　　　　}
            }
        }
    }
    catch (...)
    {
        printf ( "error catched~" );
    }

客户端：以IP 196.168.1.2为例

　int sock_fd = socket(PF_INET, SOCK_DGRAM, 0);

    if (sock_fd < 0)
    {
        printf ( "error: Create Socket Failed!" );
        return  -1;
    }

    struct  sockaddr_in addrTo;
    addrTo .sin_family = AF_INET;
    addrTo .sin_port = htons(5000);
    addrTo .sin_addr.s_addr = htonl("196.168.1.100");  //服务端的地址
    memset (addrTo.sin_zero, 0x00, 8);

    try
    {
        char  buf[256] = "This is from 196.168.1.2";
        int n ;
        struct  sockaddr_in to;
        uint32_t tolen = sizeof(struct sockaddr);
        while (1)
        {
            if ((n= recvfrom(sock_fd, recvs, 5000, 0, ( struct  sockaddr *)&addrTo, &tolen)) == -1)
            {
                printf ( "error: Receiving Failed!" );
                res = -1;
                throw  res;
            }
            else if (n > 0)
            {
　　　　　　　　printf ( "Send data to 196.168.1.100\n" );
            }
        }
    }
    catch (...)
    {
        printf ( "error catched~" );
    }