socket网络编程

一个简单的socket网络编程例子： 服务器代码： #include <winsock2.h> #include <iostream> #include <stdio.h> #include <windows.h> #pragma comment(lib,"ws2_32.lib") //这句话的意思是加载ws2_32.lib这个静态库 #define NETWORK_EVENT WM_USER+100 //如果你用mfc做开发，你可以点击菜单project-〉setting-〉link-〉object/library中添加这个静态库。 //如果你用c语言，你需要通过#pragma comment（命令来连接静态库 int main(int argc, char* argv[]){ HANDLE hThread = NULL; //判断是否输入了端口号 if(argc!=3){ printf("Usage: %sPortNumber\n",argv[1]); exit(-1); } //把端口号转化成整数 short port; if((port = atoi(argv[2]))==0){ printf("端口号有误！"); exit(-1); } WSADATA wsa; //初始化套接字DLL if(WSAStartup(MAKEWORD(2,2),&wsa)!=0){ //高字节指定了次版本号，低字节指定了主版本号，两个字节加到一起，就是你想要的Winsock库的版本号了 printf("套接字初始化失败!"); exit(-1); } //创建套接字 SOCKET serverSocket; if((serverSocket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==INVALID_SOCKET){ printf("创建套接字失败！"); exit(-1); } struct sockaddr_in serverAddress; memset(&serverAddress,0,sizeof(sockaddr_in)); serverAddress.sin_family=AF_INET; serverAddress.sin_addr.S_un.S_addr = htonl(INADDR_ANY); serverAddress.sin_port = htons(port); //绑定 if(bind(serverSocket,(sockaddr*)&serverAddress,sizeof(serverAddress))==SOCKET_ERROR){ printf("套接字绑定到端口失败！端口: %d\n",port); exit(-1); } //进入侦听状态 if(listen(serverSocket,SOMAXCONN)==SOCKET_ERROR){ printf("侦听失败！"); exit(-1); } printf("Server %d is listening......\n",port); SOCKET clientSocket[5],maxSocket;//用来和客户端通信的套接字 struct sockaddr_in clientAddress;//用来和客户端通信的套接字地址 memset(&clientAddress,0,sizeof(clientAddress)); int addrlen = sizeof(clientAddress); fd_set fd_read; int i=0; int j; char buf[4096]; char buff[4096]="exit"; while(1) { FD_ZERO(&fd_read); maxSocket=serverSocket; FD_SET(serverSocket,&fd_read); //FD_SET(clientSocket[i-1],&fd_read); for(j=0;j<i;j++) { FD_SET(clientSocket[j],&fd_read); if(maxSocket<clientSocket[j]) maxSocket=clientSocket[j]; printf("clientSocket[%d]=%d\n",j,clientSocket[j]); } //printf(">"); //gets(buff); if(select(maxSocket+1,&fd_read,NULL,NULL,NULL)>0) { if(FD_ISSET(serverSocket,&fd_read)) { if(buff=="") { if((clientSocket[i++]=accept(serverSocket,(sockaddr*)&clientAddress,&addrlen))==INVALID_SOCKET) { printf("接受客户端连接失败！"); exit(-1); } else { for(j=0;j<i;j++) { send(clientSocket[j],buff,strlen(buff),0); } printf("Accept connection from %s\n",inet_ntoa(clientAddress.sin_addr)); } } if(i>5) { printf("超过最大客户端数"); exit(-1); } } else { int bytes; for(int k=0;k<i;k++) { if(FD_ISSET(clientSocket[k],&fd_read)) { bytes=recv(clientSocket[k],buf,sizeof(buf),0); if(bytes==-1) { //listen(serverSocket,SOMAXCONN); for (int l=k;l<i;l++) clientSocket[l]=clientSocket[l+1]; i--; } /*if(bytes==0) { //printf("fdsdf"); listen(serverSocket,SOMAXCONN); for (int l=k;l<i;l++) clientSocket[l]=clientSocket[l++]; i--; }*/ else if(bytes>0) { buf[bytes]='\0'; printf("Message from %s: %s\n",inet_ntoa(clientAddress.sin_addr),buf); if(send(clientSocket[k],buf,bytes,0)==SOCKET_ERROR) { printf("发送数据失败！"); exit(-1); } } } } } } } //清理套接字占用的资源 WSACleanup(); return 0; } 客户端代码： #include <winsock2.h> #include <stdio.h> #include <windows.h> #pragma comment(lib,"ws2_32.lib") int main(int argc, char* argv[]){ //判断是否输入了IP地址和端口号 if(argc!=4){ printf("Usage: %s IPAddress PortNumber\n",argv[1]); exit(-1); } //把字符串的IP地址转化为u_long unsigned long ip; if((ip=inet_addr(argv[2]))==INADDR_NONE){ printf("不合法的IP地址：%s",argv[1]); exit(-1); } //把端口号转化成整数 short port; if((port = atoi(argv[3]))==0){ printf("端口号有误！"); exit(-1); } printf("Connecting to %s:%d......\n",inet_ntoa(*(in_addr*)&ip),port); WSADATA wsa; //初始化套接字DLL if(WSAStartup(MAKEWORD(2,2),&wsa)!=0){ printf("套接字初始化失败!"); exit(-1); } //创建套接字 SOCKET sock,serverSocket; if((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==INVALID_SOCKET){ printf("创建套接字失败！"); exit(-1); } struct sockaddr_in serverAddress; memset(&serverAddress,0,sizeof(sockaddr_in)); serverAddress.sin_family=AF_INET; serverAddress.sin_addr.S_un.S_addr = ip; serverAddress.sin_port = htons(port); //建立和服务器的连接 if(connect(sock,(sockaddr*)&serverAddress,sizeof(serverAddress))==SOCKET_ERROR) { printf("建立连接失败！"); exit(-1); } char buf[4096]; while(1){ printf(">"); //从控制台读取一行数据 gets(buf); if(send(sock,buf,strlen(buf),0)==SOCKET_ERROR){ printf("发送c数据失败！"); exit(-1); } int bytes; if((bytes=recv(sock,buf,sizeof(buf),0))==SOCKET_ERROR) { printf("接收c数据失败!\n"); exit(-1); } else { buf[bytes]='\0'; printf("Message from %s: %s\n",inet_ntoa(serverAddress.sin_addr),buf); } } //清理套接字占用的资源 WSACleanup(); return 0; }