move TCP client/server and UDP client/server example to this directory.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@457 bbd45198-f89e-11dd-88c7-29a3b14d5316

examples/network/udpclient.c

@@ -0,0 +1,42 @@
+#include <rtthread.h>
+#include <lwip/netdb.h>
+#include <lwip/sockets.h>
+
+const char send_data[] = "This is UDP Client from RT-Thread.\n";
+void udpclient(const char* url, int port, int count)
+{
+	int sock;
+	struct hostent *host;
+	struct sockaddr_in server_addr;
+
+	host= (struct hostent *) gethostbyname(url);
+
+	if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+	{
+		rt_kprintf("Socket error\n");
+		return;
+	}
+
+	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));
+
+	while (count)
+	{
+		sendto(sock, send_data, strlen(send_data), 0,
+		   (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
+
+        rt_thread_delay(50);
+
+        count --;
+	}
+
+    /* close socket */
+	lwip_close(sock);
+}
+
+#ifdef RT_USING_FINSH
+#include <finsh.h>
+FINSH_FUNCTION_EXPORT(udpclient, startup udp client);
+#endif