c++ - 创建套接字 C++

Question

我是新来的，我正在尝试测试我自己的套接字程序。

如何创建套接字？这是我正在尝试做的事情:

int main(int argc, char *argv[]) {
    int socket_addr;
    struct sockaddr_in server;
    char message[100], server_message[100];

    // Creates the socket
    socket_addr = socket(AF_INET, SOCK_STREAM, 0);
    if (socket_addr == -1) {
        cout << "Could not create the socket!";
    } else {
    //...
    }
}

编辑:这两个链接对理解套接字有很大帮助。请看他们:

1) http://beej.us/guide/bgnet/
2) https://msdn.microsoft.com/en-us/library/windows/desktop/ms742213(v=vs.85).aspx

Answer 1

既然你说你在 Windows 上，我假设你显示的代码是完整的代码，它不工作的原因是因为还没有调用 WSAStartup，这个函数初始化网络库，应在任何网络操作(如创建套接字)之前调用:

//your includes here..

#pragma comment(lib, "ws2_32.lib") // link with the network library

int main(int argc, char *argv[]) {
    int socket_addr;
    struct sockaddr_in server;
    char message[100], server_message[100];

    int wsaRes = 0;
    WSADATA wsaData = {0};
    wsaRes = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if(wsaRes != 0)
    {
      std::cerr << "WSAStartup failed!";
      return -1; 
    }
    // Creates the socket
    socket_addr = socket(AF_INET, SOCK_STREAM, 0);
    if (socket_addr == INVALID_SOCKET) {
        cout << "Could not create the socket!";
    } else {
    //...
    }
}