w5500做tcpclient通讯

发布于 2024-09-11 17:19:22 浏览：381 订阅该版

命令行调用与代码调用差异?

如何判断何时才能新建socket?

命令行调用时没有出错，可正常测试：

tcpclient 192.168.1.120 8080

使用代码调用时，出现创建sokect错误提示，调用代码：

int main(void)
{

    // 模拟命令行参数
char *fake_argv[] = { "tcpclient", "192.168.1.120", "8080" };
int fake_argc = sizeof(fake_argv) / sizeof(fake_argv[0]);
// 调用 tcpclient 函数
tcpclient(fake_argc, fake_argv);
while(1){
    rt_thread_mdelay(1000);
}

}

报错代码：

/* 创建一个socket，类型是SOCKET_STREAM，TCP类型 */
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
    /* 创建socket失败 */
    rt_kprintf("Socket error\n");
    /* 释放接收缓冲 */
    rt_free(recv_data);
    return;
}

tcpclient函数代码：

define BUFSZ 1024

static const char send_data[] = “This is TCP Client from RT-Thread.”; / 发送用到的数据 /

static void tcpclient(const int argc, char *argv)
{
char recv_data;
struct hostent host;
int sock, bytes_received;
struct sockaddr_in server_addr;
const char url;
int port, ret;

if (argc < 3)
{
    rt_kprintf("Usage: tcpclient URL PORT\n");
    rt_kprintf("Like: tcpclient 192.168.12.44 5000\n");
    return;
}
url = argv[1];
port = strtoul(argv[2], 0, 10);
/* 通过函数入口参数url获得host地址（如果是域名，会做域名解析） */
host = gethostbyname(url);
/* 分配用于存放接收数据的缓冲 */
recv_data = rt_malloc(BUFSZ);
if (recv_data == RT_NULL)
{
    rt_kprintf("No memory\n");
    return;
}
/* 创建一个socket，类型是SOCKET_STREAM，TCP类型 */
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
    /* 创建socket失败 */
    rt_kprintf("Socket error\n");
    /* 释放接收缓冲 */
    rt_free(recv_data);
    return;
}
/* 初始化预连接的服务端地址 */
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(port);
server_addr.sin_addr = *((struct in_addr *) host->h_addr);
rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));
/* 连接到服务端 */
if (connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1)
{
    /* 连接失败 */
    rt_kprintf("Connect fail!\n");
    closesocket(sock);
    /*释放接收缓冲 */
    rt_free(recv_data);
    return;
}
else
{
    /* 连接成功 */
    rt_kprintf("Connect successful\n");
}
while (1)
{
    /* 从sock连接中接收最大BUFSZ - 1字节数据 */
    bytes_received = recv(sock, recv_data, BUFSZ - 1, 0);
    if (bytes_received < 0)
    {
        /* 接收失败，关闭这个连接 */
        closesocket(sock);
        rt_kprintf("\nreceived error,close the socket.\r\n");
        /* 释放接收缓冲 */
        rt_free(recv_data);
        break;
    }
    else if (bytes_received == 0)
    {
        /* 默认 recv 为阻塞模式，此时收到0认为连接出错，关闭这个连接 */
        closesocket(sock);
        rt_kprintf("\nreceived error,close the socket.\r\n");
        /* 释放接收缓冲 */
        rt_free(recv_data);
        break;
    }
    /* 有接收到数据，把末端清零 */
    recv_data[bytes_received] = '\0';
    if (strncmp(recv_data, "q", 1) == 0 || strncmp(recv_data, "Q", 1) == 0)
    {
        /* 如果是首字母是q或Q，关闭这个连接 */
        closesocket(sock);
        rt_kprintf("\n got a 'q' or 'Q',close the socket.\r\n");
        /* 释放接收缓冲 */
        rt_free(recv_data);
        break;
    }
    else
    {
        /* 在控制终端显示收到的数据 */
        rt_kprintf("\nReceived data = %s ", recv_data);
    }
    /* 发送数据到sock连接 */
    ret = send(sock, (void * )send_data, strlen(send_data), 0);
    if (ret < 0)
    {
        /* 接收失败，关闭这个连接 */
        closesocket(sock);
        rt_kprintf("\nsend error,close the socket.\r\n");
        rt_free(recv_data);
        break;
    }
    else if (ret == 0)
    {
        /* 打印send函数返回值为0的警告信息 */
        rt_kprintf("\n Send warning,send function return 0.\r\n");
    }
}
return;