C:通过 UDP 发送 float 导致随机符号

Question

我的代码有问题，应该通过 udp 发送 float 。如果我检查我的端口传入，我只会收到随机符号而不是我想要的数字。

printf("Lets send some cool data \n");
int clientSocket;

struct sockaddr_in serverAddress;
socklen_t addressSize;

unsigned char   l_remoteHostAddr_rg4ui8[4]  = {192,168,22,160};
unsigned short  l_remoteHostPort_ui16       = 5000;
int             l_udpSocket_i32;
unsigned int    l_sendState_bl;

// open udp connection
l_udpSocket_i32 = g_halMatlab_initConnection_i32( l_remoteHostAddr_rg4ui8, l_remoteHostPort_ui16 );

halImu_orientationValues l_imuMeasurements_st;
g_halImu_initImuSensors_bl();

/*Create UDP socket*/
clientSocket = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);

serverAddress.sin_family = PF_INET;
serverAddress.sin_port = htons(REMOTE_PORT);
serverAddress.sin_addr.s_addr = inet_addr(REMOTE_ADDR);

memset(serverAddress.sin_zero, '\0', sizeof(serverAddress.sin_zero));

/*Initialize size variable to be used later on*/
addressSize = sizeof(serverAddress);

printf("Start Sending Messages\n");

int i = kbhit();
while(i != 'q')
    {
        sleep(1);
        g_halImu_triggerImuReading_bl();
        g_halImu_triggerBaroReading_bl();
        g_halImu_triggerGyroReading_bl();
        g_halImu_triggerAccReading_bl();

        l_imuMeasurements_st=g_halImu_getImuValues_str();

        l_sendState_bl = g_halMatlab_sendImuState_bl(l_udpSocket_i32, l_imuMeasurements_st);

        printf("Acc X %f \n", l_imuMeasurements_st.acc.x_f64);

        float k = l_imuMeasurements_st.acc.x_f64;

        char imu_x[16];

        sprintf(imu_x,"%f \n",k);
        printf(imu_x,'\n'); //this prints the right number 

        sendto(clientSocket, imu_x, (int)sizeof(imu_x), 0,
               (struct sockaddr *)&serverAddress,addressSize);
        printf("And send again....\n");
    }

如果我知道使用 nc -ul 5000，我会收到包含随机内容的 16 位字符串。

如果有人知道我的问题出在哪里，我会很高兴收到你的来信

祝你有美好的一天!

Answer 1

第一个问题是您发送了两次相同的数据。首先通过一个名为 clientSocket 的套接字，另一个通过另一个名为 l_udpSocket_i32 的套接字。我正在清理代码，以便只编译 clientSocket。

您的第二个问题是您试图打印 imu_x 的所有 16 个数据。您应该只打印书面字符。我添加了一个名为 written 的新变量。运行它，您将看不到任何垃圾。

printf("Lets send some cool data \n");
int clientSocket;

struct sockaddr_in serverAddress;
socklen_t addressSize;
int written;
char imu_x[16];

halImu_orientationValues l_imuMeasurements_st;
g_halImu_initImuSensors_bl();

/*Create UDP socket*/
clientSocket = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);

serverAddress.sin_family = PF_INET;
serverAddress.sin_port = htons(REMOTE_PORT);
serverAddress.sin_addr.s_addr = inet_addr(REMOTE_ADDR);

memset(serverAddress.sin_zero, '\0', sizeof(serverAddress.sin_zero));

/*Initialize size variable to be used later on*/
addressSize = sizeof(serverAddress);

printf("Start Sending Messages\n");

int i = kbhit();
while(i != 'q')
    {
        sleep(1);
        g_halImu_triggerImuReading_bl();
        g_halImu_triggerBaroReading_bl();
        g_halImu_triggerGyroReading_bl();
        g_halImu_triggerAccReading_bl();

        l_imuMeasurements_st=g_halImu_getImuValues_str();

        printf("Acc X %f \n", l_imuMeasurements_st.acc.x_f64);

        float k = l_imuMeasurements_st.acc.x_f64;


        written = sprintf(imu_x,"%f \n",k);
        printf(imu_x,'\n'); //this prints the right number 

        sendto(clientSocket, imu_x, written, 0,
               (struct sockaddr *)&serverAddress,addressSize);
        printf("And send again....\n");
    }