Windows下C++ Socket编程

红太狼 2022-05-28 13:05 214阅读 0赞

Socket编程有三种：流式套接字（SOCK\_STREAM），数据包套接字（SOCK\_DGRAM），原始套接字（SOCK\_RAW）,基于TCP的Socket编程采用流式套接字。下面分别介绍Server和Client端的编程步骤：

Server端：

1.加载套接字，创建套接字（WSAStartup()/socket）

2.绑定套接字到一个IP地址和端口（bind()）;

3.将套接字设置为监听模式等待请求连接（listen()）

4. 请求到来后，接受连接请求，返回一个新的对应于此次连接的套接字(accept());

5. 用返回的套接字和Client进行通信（send()/recv()）

6. 返回，等待另一连接请求

7. 关闭套接字，关闭加载的套接字库（closesocket()/WSAClean()）

客户端编程的步骤：

1：加载套接字库，创建套接字(WSAStartup()/socket())；

2：向服务器发出连接请求(connect())；

3：和服务器端进行通信(send()/recv())；

4：关闭套接字，关闭加载的套接字库(closesocket()/WSACleanup())。

运行：

先运行Server，在运行Client，这就是简单的C/S传输。

Server代码如下：

// Server.cpp : Defines the entry point for the console application.  
    //  
    #include "winsock2.h"  
    #pragma comment(lib, "ws2_32.lib")  
    #include <iostream>  
    using namespace std;  
    int main(int argc, char* argv[])  
    {  
        const int BUF_SIZE = 64;  
        WSADATA         wsd;            //WSADATA Variable  
        SOCKET          sServer;        //Server socket  
        SOCKET          sClient;        //Client socket  
        SOCKADDR_IN     addrServ;;      //Serevr address
        char            buf[BUF_SIZE];  //Receiving data buffer area   
        char            sendBuf[BUF_SIZE];//Return data to client
        int             retVal;         //Return value 
        //Initial socket dynamic lib  
        if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)  
        {  
            cout << "WSAStartup failed!" << endl;  
            return 1;  
        }  
          
        //Create socket 
        sServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);      
        if(INVALID_SOCKET == sServer)  
        {  
            cout << "socket failed!" << endl;  
            WSACleanup();//Release socket resource 
            return  -1;  
        }  
          
        //Set server socket address  
        addrServ.sin_family = AF_INET;  
        addrServ.sin_port = htons(4999);  
        addrServ.sin_addr.s_addr = INADDR_ANY;        
        //bind socket  
        retVal = bind(sServer, (LPSOCKADDR)&addrServ, sizeof(SOCKADDR_IN));  
        if(SOCKET_ERROR == retVal)  
        {     
            cout << "bind failed!" << endl;  
            closesocket(sServer);   
            WSACleanup();          
            return -1;  
        }  
          
        //Starting listening
        retVal = listen(sServer, 1);  
        if(SOCKET_ERROR == retVal)  
        {  
            cout << "listen failed!" << endl;         
            closesocket(sServer);   
            WSACleanup();           
            return -1;  
        }  
          
        //Receiving request from client
        sockaddr_in addrClient;  
        int addrClientlen = sizeof(addrClient);  
        sClient = accept(sServer,(sockaddr FAR*)&addrClient, &addrClientlen);  
        if(INVALID_SOCKET == sClient)  
        {  
            cout << "accept failed!" << endl;         
            closesocket(sServer);  
            WSACleanup();           
            return -1;  
        }  
          
        while(true)  
        {  
            //Receiving client data
            ZeroMemory(buf, BUF_SIZE);  
            retVal = recv(sClient, buf, BUF_SIZE, 0);  
            if (SOCKET_ERROR == retVal)  
            {  
                cout << "recv failed!" << endl;       
                closesocket(sServer);   
                closesocket(sClient);       
                WSACleanup();           
                return -1;  
            }  
            if(buf[0] == '0')  
                break;  
            cout << "The date of sending by client: " << buf <<endl;  
              
            cout << "Sending data to the client: " ;  
            cin >> sendBuf;  
              
            send(sClient, sendBuf, strlen(sendBuf), 0);  
        }  
          
        //退出  
        closesocket(sServer);   
        closesocket(sClient);   
        WSACleanup();           
          
        return 0;  
    }

Client 代码如下：

#include "winsock2.h"  
    #include <iostream>  
    #pragma comment(lib, "ws2_32.lib")  
      
    using namespace std;  
    BOOL RecvLine(SOCKET s, char* buf); //Read the data of a line  
      
    int main(int argc, char* argv[])  
    {  
    	const int BUF_SIZE = 64;  
        WSADATA wsd; //WSADATA Variable  
        SOCKET sHost; //Server socket
        SOCKADDR_IN servAddr; //Server Address  
        char buf[BUF_SIZE]; //Receiving data buffer area 
        char bufRecv[BUF_SIZE];  
        int retVal; //return value  
        //Initial socket dynamic lib
       if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)  
       {  
    	   cout << "WSAStartup failed!" << endl;  
           return -1;  
       }  
       //Create socket  
       sHost = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);  
       if(INVALID_SOCKET == sHost)  
       {  
    	   cout << "socket failed!" << endl;  
           WSACleanup();//Release socket resource  
           return  -1;  
       }  
       //Set server address 
       servAddr.sin_family =AF_INET;  
       servAddr.sin_addr.s_addr = inet_addr("127.0.0.1");  
       servAddr.sin_port = htons((short)4999);  
       int nServAddlen  = sizeof(servAddr);  
      
       //Connect Server 
       retVal=connect(sHost,(LPSOCKADDR)&servAddr, sizeof(servAddr));  
       if(SOCKET_ERROR == retVal)  
       {  
    	   cout << "connect failed!" << endl;  
           closesocket(sHost); //close socket 
           WSACleanup(); //Release socket resource   
           return -1;  
       }  
       while(true)  
       {  
    	   //Sending data to the Server 
           ZeroMemory(buf, BUF_SIZE);  
           cout << " Sending data to the Server:  ";  
           cin >> buf;  
           retVal = send(sHost, buf, strlen(buf), 0);  
           if (SOCKET_ERROR == retVal)  
           {  
    		   cout << "send failed!" << endl;  
               closesocket(sHost);  
               WSACleanup();  
               return -1;  
           }  
           //RecvLine(sHost, bufRecv);  
           ZeroMemory(bufRecv, BUF_SIZE);  
           recv(sHost, bufRecv,BUF_SIZE , 0); // Accepting data from Server,only receiving 5 characters 
           cout << endl <<"Accepting data from Server: "<< bufRecv;  
           cout<<endl;  
       }  
       //Exit  
       closesocket(sHost); 
       WSACleanup(); 
       return 0;  
    }