学步园

// 初始化环境代码

#include<winsock2.h>
#include<stdio.h>
#pragma comment(lib,"WS2_32")
class CInitSock
{
public:
CInitSock(BYTE minorVer=2,BYTE majorVer=2)
{
WSADATA wsaData;
WORD sockVersion=MAKEWORD(minorVer,majorVer);

if(::WSAStartup(sockVersion,&wsaData)!=0)
{ exit(0); }
}
~CInitSock()
{
::WSACleanup();
}

};

// Server

#include"initsock.h"

#include <stdio.h>
CInitSock initSock; // 初始化Winsock库

int main()
{
// 创建套节字
SOCKET s = ::socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if(s == INVALID_SOCKET)
{
printf("Failed socket() \n");
return 0;
}

// 填充sockaddr_in结构
sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = htons(4567);
sin.sin_addr.S_un.S_addr = INADDR_ANY;

// 绑定这个套节字到一个本地地址
if(::bind(s, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
{
printf("Failed bind() \n");
return 0;
}

printf("监听中...\r\n");
// 接收数据
char buff[1024];
sockaddr_in addr;
int nLen = sizeof(addr);
while(TRUE)
{
int nRecv = ::recvfrom(s, buff, 1024, 0, (sockaddr*)&addr, &nLen);
if(nRecv > 0)
{
buff[nRecv] = '\0';
printf(" 接收到数据（%s）：%s", ::inet_ntoa(addr.sin_addr), buff);
}

char szText[] = "UDP Server ask!\r\n";
::sendto(s, szText, sizeof(szText), 0, (sockaddr*)&addr, sizeof(addr));
}
::closesocket(s);
}

// Client

#include <stdio.h>
#include"initsock.h"
CInitSock initSock; // 初始化Winsock库

int main()
{
// 创建套节字
SOCKET sSocket = ::socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if(sSocket == INVALID_SOCKET)
{
printf("Failed socket() %d \n", ::WSAGetLastError());
return 0;
}

// 也可以在这里调用bind函数绑定一个本地地址
// 否则系统将会自动安排

// 填写远程地址信息
sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(4567);
// 注意，这里要填写服务器程序所在机器的IP地址
// 如果你的计算机没有联网，直接使用127.0.0.1即可
addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");

char szBuffer[1024] = {0};
int nLen = sizeof(addr);
while(TRUE){
// 发送数据
char szText[] = " UCP Client ask! \r\n";
::sendto(sSocket, szText, strlen(szText), 0, (sockaddr*)&addr, sizeof(addr));
::recvfrom(sSocket, szBuffer, sizeof(szBuffer), 0, (sockaddr*)&addr, &nLen);
}

::closesocket(sSocket);
return 0;
}