int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
    int nRetCode = 0;

    // initialize MFC and print and error on failure
    if (!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))
    {
        // TODO: change error code to suit your needs
        _tprintf(_T("Fatal Error: MFC initialization failed\n"));
        nRetCode = 1;
    }
    else
    {
        // TODO: code your application's behavior here.

        // Khoi tao Thu vien
        if (AfxSocketInit() == FALSE)
        {
            cout << "Khong the khoi tao Socket Libraray";
            return FALSE;
        }

        // Tao socket dau tien
        CSocket ClientSocket;
        ClientSocket.Create();


        string strIpAdr = "127.0.0.1";
        CString cstrIpAdr(strIpAdr.c_str());

        // Ket noi den Server
        if (ClientSocket.Connect(cstrIpAdr, 21) != 0)
        {
            cout << "connected to " + strIpAdr + "." << endl;
            char buffer[4096];         // Chuỗi để lưu dữ nhận từ sever, hoặc client.
            string code = "";
            string strUser = "doanmmt";
            string strPass = "123";
            string strRequest = "";
            int flag = 0;

            do
            {
                // Nhan thong diep tu Server
                memset(buffer, 0, 4096);
                ClientSocket.Receive(buffer, 4096);

                int i = 0;
                code = "";
                for (i = 0; i < 3; i++)
                {
                    code += buffer[i];
                }

                // Nếu là mã yêu cầu là nhập User.
                if (code == "220")
                {
                    char user[4096];

                    cout << buffer;
                    cout << "User (" + strIpAdr + ":(none)): ";
                    memset(user, 0, 4096);
                    fgets(user, 4096, stdin);

                    memset(buffer, 0, 4096);
                    buffer[0] = 'u';
                    buffer[1] = 's';
                    buffer[2] = 'e';
                    buffer[3] = 'r';
                    buffer[4] = ' ';

                    int i = 0;
                    for (i = 0; i < strlen(user); i++)
                    {
                        buffer[5 + i] = user[i];
                    }

                    ClientSocket.Send(buffer, strlen(buffer) + 1, 0);

                }
                else if (code == "331")
                {
                    char pass[4096];

                    cout << buffer;
                    cout << "Password: ";
                    memset(pass, 0, 4096);
                    fgets(pass, 4096, stdin);

                    memset(buffer, 0, 4096);
                    buffer[0] = 'p';
                    buffer[1] = 'a';
                    buffer[2] = 's';
                    buffer[3] = 's';
                    buffer[4] = ' ';

                    int i = 0;
                    for (i = 0; i < strlen(pass); i++)
                    {
                        buffer[5 + i] = pass[i];
                    }

                    ClientSocket.Send(buffer, strlen(buffer) + 1, 0);

                }
                else if (code == "230")
                {
                    cout << buffer;
                    flag = 1;
                }
                else if (code == "200")
                {
                    cout << buffer;

                    if (strRequest == "dir")
                    {
                        memset(buffer, 0, 4096);
                        fgets(buffer, 4096, stdin);

                        ClientSocket.Send(buffer, strlen(buffer) + 1, 0);
                    }

                }
                else if (code == "150")
                {
                    cout << buffer;
                }


                if (flag == 1)
                {
                    cout << "ftp> ";
                    cin >> strRequest;;
                    cin.ignore();

                    if (strRequest == "dir")
                    {
                        CSocket ClientSocket1;
                        ClientSocket1.Create();
                        UINT clientPort = 0;

                        if (!ClientSocket1.Connect(cstrIpAdr, 21))
                        {
                            cout << "Khong the tao data channel\n";
                            return -1;
                        }
                        else
                        {
                            cout << "Tao socket thu 2 thanh cong\n";
                            if (!ClientSocket1.GetPeerName(cstrIpAdr, clientPort))
                            {
                                cout << "Khong the xac dinh port\n";
                                return -1;
                            }
                            char buffer[4096];
                            memset(buffer, 0, 4096);
                            sprintf(buffer, "PORT %d,%d,%d,%d,%d,%d\n", 127, 0, 0, 1, clientPort / 256, clientPort % 256);
                            ClientSocket.Send(buffer, strlen(buffer));
                            cout << "Gui port thanh cong\n";
                        }

                        /*if (ClientSocket1.Connect(cstrIpAdr, 20) != 0)
                        {
                            char port[4096];

                            memset(port, 0, 4096);
                            fgets(port, 4096, stdin);

                            ClientSocket.Send(port, strlen(port) + 1, 0);
                        }
                        else
                        {
                            cout << "Khong the ket noi den Server !!!" << endl;
                        }*/
                    }

                }
            } while (1);
        }
        else
        {
            cout << "Khong the ket noi den Server !!!" << endl;
        }

        // Dong ket noi
        ClientSocket.Close();
    }

    return nRetCode;
}