diff --git a/examples/network/tcpclient.c b/examples/network/tcpclient.c
index 529c612b9a..c7a53c609f 100644
--- a/examples/network/tcpclient.c
+++ b/examples/network/tcpclient.c
@@ -1,16 +1,17 @@
 #include <rtthread.h>
-#include <lwip/netdb.h> /* 为了解析主机名，需要包含netdb.h头文件 */
+
+#include <lwip/netdb.h>   /* 为了解析主机名，需要包含netdb.h头文件 */
 #include <lwip/sockets.h> /* 使用BSD socket，需要包含sockets.h头文件 */
 
-#define BUFSZ	1024
+#define BUFSZ   1024
 
 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)
 {
+    int ret;
     char *recv_data;
     struct hostent *host;
     int sock, bytes_received;
-	int ret;
     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） */
@@ -61,15 +62,18 @@ void tcpclient(const char* url, int port)
         {
             /* 接收失败，关闭这个连接 */
             lwip_close(sock);
-            rt_kprintf("\nreceived error,close the socket.\r\n");	
+            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)
-		{
-			/* 打印recv函数返回值为0的警告信息 */
-            rt_kprintf("\nReceived warning,recv function return 0.\r\n");						
-		}
+        }
+        else if (bytes_received == 0)
+        {
+            /* 打印recv函数返回值为0的警告信息 */
+            rt_kprintf("\nReceived warning,recv function return 0.\r\n");
+            continue;
+        }
 
         /* 有接收到数据，把末端清零 */
         recv_data[bytes_received] = '\0';
@@ -78,7 +82,8 @@ void tcpclient(const char* url, int port)
         {
             /* 如果是首字母是q或Q，关闭这个连接 */
             lwip_close(sock);
-            rt_kprintf("\n got a 'q' or 'Q',close the socket.\r\n");	
+            rt_kprintf("\n got a 'q' or 'Q',close the socket.\r\n");
+
             /* 释放接收缓冲 */
             rt_free(recv_data);
             break;
@@ -91,17 +96,20 @@ void tcpclient(const char* url, int port)
 
         /* 发送数据到sock连接 */
         ret = send(sock,send_data,strlen(send_data), 0);
-		if (ret < 0)
+        if (ret < 0)
         {
             /* 接收失败，关闭这个连接 */
             lwip_close(sock);
-            rt_kprintf("\nsend error,close the socket.\r\n");		
+            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");						
-		}		
+        }
+        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;
diff --git a/examples/network/tcpsendpacket.c b/examples/network/tcpsendpacket.c
index ec23a15d23..e7c514806e 100644
--- a/examples/network/tcpsendpacket.c
+++ b/examples/network/tcpsendpacket.c
@@ -1,62 +1,67 @@
 #include <rtthread.h>
-#include <lwip/netdb.h> /* Ϊ�˽�������������Ҫ����netdb.hͷ�ļ� */
+#include <lwip/netdb.h>   /* Ϊ�˽�������������Ҫ����netdb.hͷ�ļ� */
 #include <lwip/sockets.h> /* ʹ��BSD socket����Ҫ����sockets.hͷ�ļ� */
 
 void tcp_senddata(const char* url, int port, int length)
 {
-	struct hostent *host;
-	int sock, err, result, timeout, index;
-	struct sockaddr_in server_addr;
-	rt_uint8_t *buffer_ptr;
+    struct hostent *host;
+    int sock, err, result, timeout, index;
+    struct sockaddr_in server_addr;
+    rt_uint8_t *buffer_ptr;
 
-	/* ͨ��������ڲ���url���host��ַ��������������������������� */
-	host = gethostbyname(url);
-	/* ����һ��socket��������SOCKET_STREAM��TCP���� */
-	if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
-	{
-		/* ����socketʧ�� */
-		rt_kprintf("Socket error\n");
-		return;
-	}
+    /* ͨ��������ڲ���url���host��ַ��������������������������� */
+    host = gethostbyname(url);
+    /* ����һ��socket��������SOCKET_STREAM��TCP���� */
+    if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
+    {
+        /* ����socketʧ�� */
+        rt_kprintf("Socket error\n");
+        return;
+    }
 
-	/* �����ڴ� */
-	buffer_ptr = rt_malloc(length);
-	/* ���췢������ */
-	for (index = 0; index < length; index ++)
-		buffer_ptr[index] = index & 0xff;
+    /* �����ڴ� */
+    buffer_ptr = rt_malloc(length);
+    /* ���췢������ */
+    for (index = 0; index < length; index ++)
+        buffer_ptr[index] = index & 0xff;
 
-	timeout = 100;
-	/* ���÷��ͳ�ʱʱ��100ms */
-	lwip_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout));
-	/* ��ʼ��Ԥ���ӵķ���˵�ַ */
-	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));
+    timeout = 100;
+    /* ���÷��ͳ�ʱʱ��100ms */
+    lwip_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout));
+    /* ��ʼ��Ԥ���ӵķ���˵�ַ */
+    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));
 
-	/* ���ӵ������ */
-	err = connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
-	rt_kprintf("TCP thread connect error code: %d\n", err);
+    /* ���ӵ������ */
+    err = connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
+    rt_kprintf("TCP thread connect error code: %d\n", err);
 
-	while(1)
-	{
-		/* �������ݵ�sock���� */
-		result = send(sock, buffer_ptr, length, MSG_DONTWAIT);
-		if(result == -1) //���ݷ��ʹ�����
-		{
-			rt_kprintf("TCP thread send error: %d\n", result);
-			lwip_close(sock);	//�ر����ӣ����´�������
-			rt_thread_delay(10);
-			if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
-				rt_kprintf("TCP Socket error:%d\n",sock);
-			err = connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
-			rt_kprintf("TCP thread connect error code: %d\n", err);
-		}else if (result == 0)
-		{
-			/* ��ӡsend��������ֵΪ0�ľ�����Ϣ */
-            rt_kprintf("\n Send warning,send function return 0.\r\n");						
-		}	
-	}
+    while(1)
+    {
+        /* �������ݵ�sock���� */
+        result = send(sock, buffer_ptr, length, MSG_DONTWAIT);
+        if(result < 0) //���ݷ��ʹ�����
+        {
+            rt_kprintf("TCP thread send error: %d\n", result);
+            lwip_close(sock);
+
+            /* �ر����ӣ����´������� */
+            rt_thread_delay(10);
+
+            if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
+                rt_kprintf("TCP Socket error:%d\n",sock);
+
+            err = connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
+            rt_kprintf("TCP thread connect error code: %d\n", err);
+        }
+        else if (result == 0)
+        {
+            /* ��ӡsend��������ֵΪ0�ľ�����Ϣ */
+            rt_kprintf("\n Send warning,send function return 0.\r\n");
+        }
+    }
 }
 
 #ifdef RT_USING_FINSH
diff --git a/examples/network/tcpserver.c b/examples/network/tcpserver.c
index e68d9e53f0..c08949ea83 100644
--- a/examples/network/tcpserver.c
+++ b/examples/network/tcpserver.c
@@ -74,18 +74,19 @@ void tcpserv(void* parameter)
        {
            /* 发送数据到connected socket */
            ret = send(connected, send_data, strlen(send_data), 0);
-		   if (ret < 0)
-		   {
-				/* 接收失败，关闭这个连接 */
-				lwip_close(sock);
-				rt_kprintf("\nsend error,close the socket.\r\n");		
-				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");						
-		   }		
-		   
+           if (ret < 0)
+           {
+                /* 发送失败，关闭这个连接 */
+                lwip_close(connected);
+                rt_kprintf("\nsend error,close the socket.\r\n");
+                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");
+           }
+
            /* 从connected socket中接收数据，接收buffer是1024大小，但并不一定能够收到1024大小的数据 */
            bytes_received = recv(connected,recv_data, 1024, 0);
            if (bytes_received < 0)
@@ -93,11 +94,13 @@ void tcpserv(void* parameter)
                /* 接收失败，关闭这个connected socket */
                lwip_close(connected);
                break;
-           }else if (bytes_received == 0)
-		   {
-			   /* 打印recv函数返回值为0的警告信息 */
-			   rt_kprintf("\nReceived warning,recv function return 0.\r\n");						
-		   }
+           }
+           else if (bytes_received == 0)
+           {
+               /* 打印recv函数返回值为0的警告信息 */
+               rt_kprintf("\nReceived warning,recv function return 0.\r\n");
+               continue;
+           }
 
            /* 有接收到数据，把末端清零 */
            recv_data[bytes_received] = '\0';