1  int WSAStartup(WORD wVersionRequested,LPWSADATA lpWSAData);

 1 #include <WinSock2.h> 2 #include <iostream> 3  4 namespace WinSock { 5  6     void ErrorHandling(char* message) { 7         std::cerr << message << std::endl; 8         exit(1); 9     }10 11     int Server(int port) {12         WSADATA wsaData;13         SOCKET hServSock, hClntSock;14         SOCKADDR_IN servAddr, clntAddr;15         int szClntAddr;16         char message[] = "Hello World!";17         if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) ErrorHandling("WSAStartup() error");18         hServSock = socket(PF_INET, SOCK_STREAM, 0);19         if (hServSock == INVALID_SOCKET) ErrorHandling("socket() error");20         memset(&servAddr, 0, sizeof(servAddr));21         servAddr.sin_family = AF_INET;22         servAddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);23         servAddr.sin_port = htons(port);24         if (bind(hServSock, (SOCKADDR*)&servAddr, sizeof(servAddr)) == SOCKET_ERROR) ErrorHandling("bind() error");25         if (listen(hServSock, 5) == SOCKET_ERROR) ErrorHandling("listen() error");26         szClntAddr = sizeof(clntAddr);27         hClntSock = accept(hServSock, (SOCKADDR*)&clntAddr, &szClntAddr);28         if (hClntSock == INVALID_SOCKET) ErrorHandling("accept() error");29         send(hClntSock, message, sizeof(message), 0);30         closesocket(hClntSock);31         closesocket(hServSock);32         WSACleanup();33         return 0;34     }35 36     int Client(char ip[], int port) {37         WSADATA wsaData;38         SOCKET hSocket;39         SOCKADDR_IN servAddr;40         char message[30];41         int strLen;42         if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) ErrorHandling("WSAStartup() error");43         hSocket = socket(PF_INET, SOCK_STREAM, 0);44         if (hSocket == INVALID_SOCKET) ErrorHandling("socket() error");45         memset(&servAddr, 0, sizeof(servAddr));46         servAddr.sin_family = AF_INET;47         servAddr.sin_addr.S_un.S_addr = inet_addr(ip);48         servAddr.sin_port = htons(port);49         if (connect(hSocket, (SOCKADDR*)&servAddr, sizeof(servAddr)) == SOCKET_ERROR) ErrorHandling("connect() error");50         strLen = recv(hSocket, message, sizeof(message) - 1, 0);51         if (strLen == -1) ErrorHandling("read() error");52         std::cout << "Message from server: " << message << std::endl;53         closesocket(hSocket);54         WSACleanup();55         return 0;56     }57 58 };