Error “Attempted to access an unnamed file past its end.” when data receive over sock

[megharbhamare]

I have an MFC server which is listening on a port all the time. Now my requirement is to send data over the socket(using TCP/IP) to this server from a client written in python 3.6.

The python client sends the bytes, but once I receive data at the server end, the exception is thrown "Attempted to access an unnamed file past its end."

//Server code snippet

void CClientSocket::ReceiveMsg(CMsg* pMsg)
{
    pMsg->Serialize(*m_pArchiveIn);
}

void CMsg::Serialize(CArchive& ar)
{
    if (ar.IsStoring())
    {
        ar << (WORD)bClose;
        ar << m_strText;
    }
    else
    {
        WORD wd;
        ar >> wd;
        bClose = (BOOL)wd;
        ar >> m_strText;
    }
    m_msgList.Serialize(ar);
}

//Client code

'''
    Simple socket client
'''

import socket
import sys

def testme():
    PlayerHost = "127.0.0.1"
    PlayerPort = 501
    try:
        print ("Connecting --- to server" + PlayerHost)
        playerSoc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        playerSoc.connect((PlayerHost,PlayerPort))
    except e:
            print ("Connectiong error")
            print(e)

    try:
        dataSendCommand = '$Command Command 0 100';
        print ('---Before encode Command' + dataSendCommand);
        #print ('After encode command' + dataSendCommand.encode());
        nbytes  = playerSoc.send(dataSendCommand);
        print(nbytes);
        playerSoc.close();

    except e:
        print ("Some issue")


testme()
exit(0)

I am not much aware of how to MFC sockets are working with CArchive and what exactly happens in there. Also, if I send message from C++ client, it works fine. Any help on how to send data from python to MFC C++ server which is compatible so that receive is successful is what I want know. Your help appreciated.

I have the following in MFC C++ which I want to replicate in python but I am not sure on the datatype to be used.

USES_CONVERSION;
       char buf[1024];
       int nBufLen1;

       CString sendBuffer("$MyCommand Hi");
       //int nBufLen1 = sendBuffer.GetLength();
       buf[0] = 0;
       buf[1] = 0;
       WORD len = sendBuffer.GetLength() * 2;
       nBufLen1 = len + 5;  // length of message

       buf[2] = (BYTE)len;
       char *pStr = T2A(sendBuffer);
       strncpy(&buf[3],pStr,len);    // actual string to send

       buf[len + 3] = 0;
       buf[len + 4] = 0;


       if(sock.Send (&buf,nBufLen1) != nBufLen1)
       {
              OutputDebugString(L"Socket Send Failed");
              return FALSE;
       }

Can anyone help me with the datatype ?

Since I am new to python here is what i tried

bufArr2 = ["0" , "0" , "26" , "$MyCommand Hi" , "0" , "0"]
print(bufArr2[3]);
nbytes  = playerSoc.send(bufArr2.encode()); //Error

I received error "descriptor 'encode' requires a 'str' object but received a 'list'"

Not sure on how to send the list as bytes. Also, not sure if there is something else that I can use instead of list.

Megha

[VictorN]

The problem seems to be in the CArchive class.
There are some discussions on different Forums that may help:
http://forums.codeguru.com/showthrea...-error-message
https://social.msdn.microsoft.com/Fo...orum=vcgeneral
http://forums.codeguru.com/showthrea...hive-Exception
https://www.google.de/search?newwind....0.2F1zRDG777o