C++学习-Socket入门实验

Server端代码：

#include <winsock2.h>
#include <stdio.h>
#include <iostream>
#pragma comment(lib,"ws2_32.lib")
#include <vector>
#define SIZE_BUFFER 200
int main(){
	WSAData wsadata;
	WSAStartup(MAKEWORD(2,0),&wsadata);
	SOCKET ssocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);//创建一个TCP的Socket，但是没有绑定
	struct sockaddr_in server;
	server.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	server.sin_family = AF_INET;
	server.sin_port = htons(25000);//创建一个端口地址，指定地址和端口号
	 
	if(bind(ssocket,(sockaddr*)&server,sizeof(sockaddr_in)) == SOCKET_ERROR){
		std::cout<<"error bind"<<std::endl;
	}//绑定TCP Socket到指定的端口地址
	if(listen(ssocket, 4) == SOCKET_ERROR){
		std::cout<<"listen error"<<std::endl;
	}

	fd_set read_fdset;//读文件描述符
	std::vector<int> sockets;//读端口的集合，每监听到一个请求，就会新建一个端口，并且存放到该集合中
	
	while(true){
		FD_ZERO(&read_fdset);
		FD_SET(ssocket,&read_fdset);
		int n = select(0,&read_fdset,NULL,NULL,0);
		if(FD_ISSET(ssocket,&read_fdset)){//如果监听端口接收到了读的请求，也就是客户端发起了请求连接
			SOCKET s = accept(ssocket,NULL,0);//创建一个新的端口
			if(n!=SOCKET_ERROR){
				sockets.push_back(s);
				FD_SET(s,&read_fdset);//将当前端口设置到FD_READ中
			}
		}

		for(int i=0;i<sockets.size();i++){//对每一个接收端口查看是否有数据接收
			char buffer[SIZE_BUFFER];
			memset(buffer,0,SIZE_BUFFER);
			int len = 0;
			if((len = recv(sockets[i],buffer,SIZE_BUFFER,0))>0){
				printf("recv size = %d, and msg = %s\n",len,buffer);
			}//len：0代表客户端连接了连接，负值代表连接出错，正值代表接收数据的长度
			else if(len == 0){//客户端断开连接，删除集合
				sockets.erase(sockets.begin()+i);
			}
			
		}
	}
	system("pause");
	WSACleanup();
	return 0;

}

Client端代码：

#include <winsock2.h>
#include <iostream>
#include <stdio.h>
#pragma comment(lib,"ws2_32.lib")
int main(){
	WSADATA wdata;
	WSAStartup(MAKEWORD(2,0),&wdata);
	SOCKADDR_IN addr;
	addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	addr.sin_family = AF_INET;
	addr.sin_port = htons(25000);
	SOCKET cons = socket(AF_INET,SOCK_STREAM,0);
	//bind(cons,(sockaddr*)&addr,0);
	
	SOCKET s = connect(cons,(sockaddr*)&addr,sizeof(SOCKADDR_IN));
	if( s == SOCKET_ERROR ){
		std::cout<< s << std::endl;
	}
	fd_set readset,writeset,exceptset;
	FD_ZERO(&writeset);
	FD_SET(s,&writeset);
	while(true){
		select(0,&readset,&writeset,&exceptset,0);
		if(FD_ISSET(s,&writeset)){
			
			int size = send(cons,"hello",6,0);
			std::cout<<"send msg size = "<<size<<std::endl;
			closesocket(s);
			WSACleanup();
			break;
		}
	}
	system("pause");
	WSACleanup();
	return 0;
}