diff --git a/examples/network/tcpclient.c b/examples/network/tcpclient.c
index 9927847f74c7b44f9866a7768550f1b3d4407627..f583fb40ff26af0d92c11a6e5f9043dbf581742e 100644
--- a/examples/network/tcpclient.c
+++ b/examples/network/tcpclient.c
@@ -7,87 +7,88 @@
 static const char send_data[] = "This is TCP Client from RT-Thread."; /* 发送用到的数据 */
 void tcpclient(const char* url, int port)
 {
-   char *recv_data;
-   struct hostent *host;
-   int sock, bytes_received;
-   struct sockaddr_in server_addr;
-
-   /* 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 error\n");
-
-       /*释放接收缓冲 */
-       rt_free(recv_data);
-       return;
-   }
-
-   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 */
-           lwip_close(sock);
-
-           /* 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 (strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
-       {
-           /* 如果是首字母是q或Q，关闭这个连接 */
-           lwip_close(sock);
-
-           /* 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("\nRecieved data = %s " , recv_data);
-       }
-
-       /* 发送数据到sock连接 */
-       send(sock,send_data,strlen(send_data), 0);
-   }
-
-   return;
+    char *recv_data;
+    struct hostent *host;
+    int sock, bytes_received;
+    struct sockaddr_in server_addr;
+
+    /* 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");
+        lwip_close(sock);
+
+        /*释放接收缓冲 */
+        rt_free(recv_data);
+        return;
+    }
+
+    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 */
+            lwip_close(sock);
+
+            /* 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 (strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
+        {
+            /* 如果是首字母是q或Q，关闭这个连接 */
+            lwip_close(sock);
+
+            /* 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("\nRecieved data = %s " , recv_data);
+        }
+
+        /* 发送数据到sock连接 */
+        send(sock,send_data,strlen(send_data), 0);
+    }
+
+    return;
 }
 
 #ifdef RT_USING_FINSH