写一段lwip demo程序
时间: 2023-10-06 18:11:09 浏览: 39
下面是一个简单的lwip demo程序,用于实现TCP连接:
```c
#include "lwip/opt.h"
#include "lwip/sys.h"
#include "lwip/api.h"
#define SERVER_IP "192.168.1.100"
#define SERVER_PORT 8080
static void tcp_client_thread(void *arg)
{
err_t err;
struct netconn *conn;
struct netbuf *buf;
char *send_data = "hello world!";
char recv_data[100];
conn = netconn_new(NETCONN_TCP);
if (conn == NULL) {
printf("create tcp connection failed\r\n");
return;
}
err = netconn_connect(conn, IPADDR_ANY, SERVER_PORT);
if (err != ERR_OK) {
printf("connect to server failed\r\n");
netconn_delete(conn);
return;
}
err = netconn_write(conn, send_data, strlen(send_data), NETCONN_NOCOPY);
if (err != ERR_OK) {
printf("send data to server failed\r\n");
netconn_delete(conn);
return;
}
err = netconn_recv(conn, &buf);
if (err != ERR_OK) {
printf("recv data from server failed\r\n");
netconn_delete(conn);
return;
}
netbuf_copy(buf, recv_data, netbuf_len(buf));
printf("recv data from server: %s\r\n", recv_data);
netbuf_delete(buf);
netconn_delete(conn);
}
int main(void)
{
sys_init();
tcp_client_thread(NULL);
return 0;
}
```
该程序通过创建一个`netconn`对象实现TCP连接,并发送一条消息到指定的IP地址和端口号,并且接收来自服务器的响应。注意,这里使用了硬编码的IP地址和端口号,实际应用中需要根据需要进行修改。