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Visual C++ - Socket Programming - Sample TCP Client / Server Application





I have come up with a Sample TCP Client / Server application. GUI is designed with MFC dialog based application with multhithreading enabled on the server code.  

 

The complete source code and executable linkes are given at the bottom of this page.

 


Source Code


 

void CSocketTestClientDlg::OnBnClickedOk()

{

  

    SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    if(s == -1)

    {

        AfxMessageBox("Socket Initialiation Error");

    }

    SOCKADDR_IN serveraddr;

    struct hostent *hostentry;

 

   

    bool bSent = false;

    std::string server = "localhost";

    int portno = 1818;

   

    hostentry = gethostbyname(server.c_str());

    char *pipaddr = inet_ntoa (*(struct in_addr *)*hostentry->h_addr_list);

 

     memset(&serveraddr,0, sizeof(serveraddr));

     serveraddr.sin_family = AF_INET;

     serveraddr.sin_port = htons(portno);

     serveraddr.sin_addr.s_addr = inet_addr(pipaddr);

 

    //serv_addr.sa_data = htons(portno);

 

    if (connect(s,(SOCKADDR*)&serveraddr,sizeof(SOCKADDR_IN)) < 0)

    {

         AfxMessageBox("ERROR connecting to the server");

         exit(1);

    }

 

    char sbuf[1024], rbuf[1024];

   

    UpdateData(TRUE);

    sprintf(sbuf,"%s\r\n", (const char*) m_senddata);

    if(send(s, sbuf, strlen(sbuf), 0) == strlen(sbuf))

    {

        recv(s, rbuf, 1024, 0);

        m_recvData = rbuf;

        UpdateData(FALSE);

    }

    ::closesocket(s);

}

 

 

void CSocketTestServerDlg::StartServer()

{

      SOCKADDR_IN serveraddr;

    int portno = 1818;

    memset(&serveraddr,0, sizeof(serveraddr));

    serveraddr.sin_family = AF_INET;

    serveraddr.sin_port = htons(portno);

    serveraddr.sin_addr.s_addr = INADDR_ANY;

 

    m_serversocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    if(m_serversocket == -1)

    {

        AfxMessageBox("Socket Initialiation Error");

    }

 

    if(bind(m_serversocket, (SOCKADDR*)&serveraddr,sizeof(SOCKADDR_IN)) < 0)

    {

         AfxMessageBox("ERROR binding in the server socket");

         exit(1);

    }

 

    if(listen(m_serversocket,0) < 0)

    {

         AfxMessageBox("ERROR listening in the server socket");

         exit(1);

    }

 

    SetTimer(0x01, 100, NULL);

}

 

static void f(void *p)

{

    CSocketTestServerDlg *pDlg = reinterpret_cast<CSocketTestServerDlg*>(p);

    pDlg->ProcessClientRequest();

}

 

void CSocketTestServerDlg::ProcessClientRequest()

{

    SOCKADDR_IN clientaddr;

    struct hostent *hostentry;

    int len = sizeof(clientaddr);

    SOCKET clientsocket = accept(m_serversocket, (sockaddr*)&clientaddr, &len);

   

    if(len == -1)

    {

        AfxMessageBox("Error accpeting the client socket");

    }

    else

    {

        char *p = inet_ntoa(clientaddr.sin_addr);

        int portno = ntohs(clientaddr.sin_port);

        // int inet_pton(int af, const char *restrict src, void *restrict dst);

 

        char rbuf[1024];

        recv(clientsocket, rbuf, 1024, 0);

        for(int i = 1024; i >= 1; i--)

        {

            if(rbuf[i] == '\n' && rbuf[i - 1] == '\r')

            {

                rbuf[i-1] = '\0';

                break;

            }

        }

        CString strRecvData;

       

        strRecvData.Format("%s\r\n%s %d\r\n%s\r\n\r\n", (const char*)CTime::GetCurrentTime().Format("%B %d, %Y %H:%M:%S"), p, portno, rbuf);

        m_recvData += strRecvData;

        m_bRefershData = true;

        strcat(rbuf, "\r\n");

        send(clientsocket, rbuf, 1024, 0);

        closesocket(clientsocket);

    }

}

 

void CSocketTestServerDlg::OnTimer(UINT_PTR nIDEvent)

{

    int idx = nIDEvent;

 

    if(m_bRefershData == true)

    {

        m_bRefershData = false;

        UpdateData(FALSE);

    }

 

    fd_set fds;

    struct timeval timeout;

    int result;

    timeout.tv_sec = 0;

    timeout.tv_usec = 100;

 

    FD_ZERO(&fds);

    FD_SET(m_serversocket, &fds);

 

    int rc = select(sizeof(fds)*8, &fds, NULL, NULL, &timeout);

    if (rc==-1)

    {

      AfxMessageBox("ERROR selecting in the server socket");

      return;

    }

    else if(rc > 0)

    {

        if (FD_ISSET(m_serversocket, &fds))

        {

            m_bRefershData = false;

            HANDLE h = (HANDLE) ::_beginthread(f, 0, (void*) this);

        }

       

    }       

    CDialog::OnTimer(nIDEvent);

}


Click here to download the Visual C++ source code and executable file


Output