这里我们给出了linux下C++的socket代码如下：

　　#include <iostream>

　　#include <stdio.h>

　　#include <sys/socket.h>

　　#include <unistd.h>

　　#include <sys/types.h>

　　#include <netinet/in.h>

　　#include <stdlib.h>

　　#include <time.h>

　　#include <string.h>

　　#include <stdlib.h>

　　using namespace std;

　　int main (int argc, char *argv[])

　　{

　　cout << "Hello world!" << endl;

　　int localSocket,remoteSocket;

　　struct sockaddr_in  localAddr,remoteAddr;

　　localSocket = socket(AF_INET, SOCK_DGRAM, 0);

　　bzero(&localAddr, sizeof(localAddr));

　　localAddr.sin_family = AF_INET;

　　localAddr.sin_port = htons(53);

　　localAddr.sin_addr.s_addr = INADDR_ANY;

　　cout << "socket returned : " << localSocket << endl;

　　int result = bind(localSocket, (struct sockaddr *)&localAddr, sizeof(localAddr));

　　cout << "bind returned : " << result << endl;

　　while(1)

　　{

　　char buffer[1024];

　　socklen_t remoteAddrLength = sizeof(remoteAddr);

result = recvfrom(localSocket, &buffer, sizeof(buffer), 0, (struct sockaddr *)&remoteAddr, &remoteAddrLength);

　　cout << "received UDP data." << endl;

　　//构建一个char[]缓冲区，包含要发送的数据，在这里可以自己定义要发送的数据。

　　char sendBuff[512];

　　memset(sendBuff, 0, sizeof(sendBuff));

　　sendto(localSocket, &sendBuff, sizeof(sendBuff),0, (struct sockaddr *)&remoteAddr ,remoteAddrLength);

　　}