what could be the reason my message is received with extra characters?

Question

I'm trying to make a program that sends information (set of characters) to another program (client/sever) with winsock for my school project.

the message I send is received on the other side, but with extra characters at the end. I.E. if I wanted to send "hallo" I receive "hallod3" or some random symbols.

P.S: the message is sent from the Client to the Server

here's my code on the server:

 char recvbuf[DEFAULT_BUFLEN];
    int recvbuflen = DEFAULT_BUFLEN;

  do {

        iResult = recv(ClientSocket, recvbuf, recvbuflen, 0);     
        if (iResult > 0) {
            ShowMessage(recvbuf);
        }

        else if (iResult == 0)
            ShowMessage("Connection closing...\n");
        else  {
            ShowMessage("recv failed with error: %d\n", WSAGetLastError());
            closesocket(ClientSocket);
            WSACleanup();
            ShowMessage("send failed");
        }
     } while (iResult > 0);

and here's the client:

 char sendbuf[DEFAULT_BUFLEN];

  iResult = send( ConnectSocket, sendbuf, (int)strlen(sendbuf), 0 );
    if (iResult == SOCKET_ERROR) {
        ShowMessage("send failed with error: %d\n", WSAGetLastError());
        closesocket(ConnectSocket);
        WSACleanup();
       ShowMessage("send failed");
    }

DEFAULT_BUFLEN is defined (length of the message), ShowMessage() is a function from VCL component (I'm using Borland C++ Builder) that takes a string and displays it.

P.S: I made sure of the string 'sendbuf' in the client and there's no extra character, I even add '\0' in the end of the string.

what could be the problem here ?

Answer 1

It isn't 'received with extra characters'. It's just that you're ignoring iResult when displaying the receive buffer. It's only valid for iResult bytes, not the whole thing.