Windows下C语言的Socket编程例子（TCP和UDP）

转载：http://www.cnblogs.com/churi/archive/2013/02/27/2935427.html

一、TCP

服务器端

#include "stdafx.h"
#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib,"ws2_32.lib")

int main(int argc, char* argv[])
{
    //初始化WSA
    WORD sockVersion = MAKEWORD(2,2);
    WSADATA wsaData;
    if(WSAStartup(sockVersion, &wsaData)!=0)
    {
        return 0;
    }

    //创建套接字
    SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if(slisten == INVALID_SOCKET)
    {
        printf("socket error !");
        return 0;
    }

    //绑定IP和端口
    sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(8888);
    sin.sin_addr.S_un.S_addr = INADDR_ANY; 
    if(bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
    {
        printf("bind error !");
    }

    //开始监听
    if(listen(slisten, 5) == SOCKET_ERROR)
    {
        printf("listen error !");
        return 0;
    }

    //循环接收数据
    SOCKET sClient;
    sockaddr_in remoteAddr;
    int nAddrlen = sizeof(remoteAddr);
    char revData[255]; 
    while (true)
    {
        printf("等待连接...\n");
        sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
        if(sClient == INVALID_SOCKET)
        {
            printf("accept error !");
            continue;
        }
        printf("接受到一个连接：%s \r\n", inet_ntoa(remoteAddr.sin_addr));
        
        //接收数据
        int ret = recv(sClient, revData, 255, 0);        
        if(ret > 0)
        {
            revData[ret] = 0x00;
            printf(revData);
        }

        //发送数据
        char * sendData = "你好，TCP客户端！\n";
        send(sClient, sendData, strlen(sendData), 0);
        closesocket(sClient);
    }
    
    closesocket(slisten);
    WSACleanup();
    return 0;
}

客户端

#include "stdafx.h"
#include <WINSOCK2.H>
#include <STDIO.H>

#pragma  comment(lib,"ws2_32.lib")


int main(int argc, char* argv[])
{
    WORD sockVersion = MAKEWORD(2,2);
    WSADATA data; 
    if(WSAStartup(sockVersion, &data) != 0)
    {
        return 0;
    }

    SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if(sclient == INVALID_SOCKET)
    {
        printf("invalid socket !");
        return 0;
    }

    sockaddr_in serAddr;
    serAddr.sin_family = AF_INET;
    serAddr.sin_port = htons(8888);
    serAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); 
    if (connect(sclient, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
    {
        printf("connect error !");
        closesocket(sclient);
        return 0;
    }
    char * sendData = "你好，TCP服务端，我是客户端!\n";
    send(sclient, sendData, strlen(sendData), 0);

    char recData[255];
    int ret = recv(sclient, recData, 255, 0);
    if(ret > 0)
    {
        recData[ret] = 0x00;
        printf(recData);
    }
    closesocket(sclient);
    WSACleanup();
    return 0;
}

二、UDP

服务器端

#include "stdafx.h"
#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib") 

int main(int argc, char* argv[])
{
    WSADATA wsaData;
    WORD sockVersion = MAKEWORD(2,2);
    if(WSAStartup(sockVersion, &wsaData) != 0)
    {
        return 0;
    }

    SOCKET serSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); 
    if(serSocket == INVALID_SOCKET)
    {
        printf("socket error !");
        return 0;
    }

    sockaddr_in serAddr;
    serAddr.sin_family = AF_INET;
    serAddr.sin_port = htons(8888);
    serAddr.sin_addr.S_un.S_addr = INADDR_ANY;
    if(bind(serSocket, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
    {
        printf("bind error !");
        closesocket(serSocket);
        return 0;
    }
    
    sockaddr_in remoteAddr;
    int nAddrLen = sizeof(remoteAddr); 
    while (true)
    {
        char recvData[255];  
        int ret = recvfrom(serSocket, recvData, 255, 0, (sockaddr *)&remoteAddr, &nAddrLen);
        if (ret > 0)
        {
            recvData[ret] = 0x00;
            printf("接受到一个连接：%s \r\n", inet_ntoa(remoteAddr.sin_addr));
            printf(recvData);            
        }

        char * sendData = "一个来自服务端的UDP数据包\n";
        sendto(serSocket, sendData, strlen(sendData), 0, (sockaddr *)&remoteAddr, nAddrLen);    

    }
    closesocket(serSocket); 
    WSACleanup();
    return 0;
}

客户端

#include "stdafx.h"
#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib") 

int main(int argc, char* argv[])
{
    WORD socketVersion = MAKEWORD(2,2);
    WSADATA wsaData; 
    if(WSAStartup(socketVersion, &wsaData) != 0)
    {
        return 0;
    }
    SOCKET sclient = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    
    sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(8888);
    sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    int len = sizeof(sin);
    
    char * sendData = "来自客户端的数据包.\n";
    sendto(sclient, sendData, strlen(sendData), 0, (sockaddr *)&sin, len);

    char recvData[255];     
    int ret = recvfrom(sclient, recvData, 255, 0, (sockaddr *)&sin, &len);
    if(ret > 0)
    {
        recvData[ret] = 0x00;
        printf(recvData);
    }

    closesocket(sclient);
    WSACleanup();
    return 0;
}