Windows环境下，面向连接的套接字编程实例（c++实现）

/* #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include <stdio.h> */ #include <string.h> #include <WinSock2.h> #pragma comment(lib,"ws2_32.lib") #include <iostream> using namespace std; #define PROTOPORT 5188 //extern int erron; char localhost[] = "localhost"; int main(int argc, char* argv[]) { struct hostent* ptrh; struct sockaddr_in servaddr; SOCKET sockfd; //windows采用大写的SOCKET int port; char* host; int n; char buf[1000]; WSADATA wsaData; WSAStartup(MAKEWORD(2, 0), &wsaData); memset((char*)&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; /*检查命令行参数，如果有，就抽取端口号；否则使用内定的默认值*/ if (argc > 2) { port = atoi(argv[2]); } else { port = PROTOPORT; } if (port > 0) { servaddr.sin_port = htons((u_short)port); } else { //fprintf(stderr, "bad port number %s \n", argv[2]); //exit(1); cout << "bad port number %s" << argv[2] << endl; return 1; } /*检查主机参数并指定主机名*/ if (argc > 1) { host = argv[1]; } else { host = localhost; } /*将主机名转换成相应的IP地址并复制到servaddr结构中*/ ptrh = gethostbyname(host); //if ((char*)ptrh == null) if ((char*)ptrh == NULL) { //fprintf(stderr, "invalid host %s \n", host); //exit(1); cout << "invalid host %s" << host << endl; return 1; } memcpy(&servaddr.sin_addr, ptrh->h_addr, ptrh->h_length); /*创建一个套接字*/ sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd == INVALID_SOCKET) { //fprintf(stderr, "socket creation failed\n"); //exit(1); cout << "socket creation failed" << WSAGetLastError() << endl; return 1; } /*请求连接到服务器*/ if (connect(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) == SOCKET_ERROR) { //fprintf(stderr, "connect failed\n"); //exit(1); cout << "connect failed" << WSAGetLastError() << endl; return 1; } /*从套接字反复读数据，并输出到用户屏幕上*/ memset((char*)&buf, 0, sizeof(buf)); n = recv(sockfd, buf, sizeof(buf), 0); while (n > 0) { //write(1, buf, n);//1表示标准输出的文件描述符，这句话的作用是把buf的内容打印到屏幕 cout.write(buf, n); n = recv(sockfd, buf, sizeof(buf), 0); } /*关闭套接字*/ closesocket(sockfd); /*注销winsock*/ WSACleanup(); /*终止客户程序*/ //exit(0); return 0; }