(DataFlex) Transfer a File using Sockets (TLS or non-TLS)

Demonstrates how to two programs, one a socket writer and the other a socket reader, can transfer a file. The connection can be TLS or a regular non-encrypted TCP connection.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Variant vBdToSend
    Handle hoBdToSend
    Boolean iSuccess
    Handle hoSndSock
    Boolean iBUseTls
    Integer iPort
    Integer iMaxWaitMs
    Integer iNumBytes
    Boolean iBBigEndian
    Handle hoListenSock
    Variant vRcvSock
    Handle hoRcvSock
    Integer iNumBytesComing
    Variant vBdReceived
    Handle hoBdReceived
    Integer iMaxWaitMs
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // On the sending side, we'll load the file into a BinData object and send.
    // On the receiving side, we'll read from the socket connection into a BinData, and save to a file.
    // This example assumes the file is not crazy-large, and that the entire contents
    // can fit into memory.  
    // (If the file is too large for memory, there are other ways to send. It just involves streaming or 
    // sending the file chunk-by-chunk..)

    // This section of code is for the sender.
    Get Create (RefClass(cComChilkatBinData)) To hoBdToSend
    If (Not(IsComObjectCreated(hoBdToSend))) Begin
        Send CreateComObject of hoBdToSend
    End
    Get ComLoadFile Of hoBdToSend "somePath/someFile.dat" To iSuccess
    // Assume success for the example...

    Get Create (RefClass(cComChilkatSocket)) To hoSndSock
    If (Not(IsComObjectCreated(hoSndSock))) Begin
        Send CreateComObject of hoSndSock
    End
    Move True To iBUseTls
    Move 5555 To iPort
    Move 5000 To iMaxWaitMs
    Get ComConnect Of hoSndSock "some_domain_or_ip.com" iPort iBUseTls iMaxWaitMs To iSuccess
    // Assume success for the example...

    // Tell the receiver how many bytes are coming.
    Get ComNumBytes Of hoBdToSend To iNumBytes
    Move True To iBBigEndian
    Get ComSendInt32 Of hoSndSock iNumBytes iBBigEndian To iSuccess

    // Send the file data (sends the entire contents of bdToSend).
    Get pvComObject of hoBdToSend to vBdToSend
    Get ComSendBd Of hoSndSock vBdToSend 0 0 To iSuccess

    // Get an acknowledgement.
    Get ComReceiveInt32 Of hoSndSock iBBigEndian To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSndSock To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Did the receiver get the correct number of bytes?
    Get ComReceivedInt Of hoSndSock To iTemp1
    If (iTemp1 <> iNumBytes) Begin
        Showln "The receiver did not acknowledge with the correct number of bytes."
        Procedure_Return
    End

    Showln "File sent!"

    // ------------------------------------------------------------------------------------
    // The code below is for the receiving side (running on some other computer..)

    Get Create (RefClass(cComChilkatSocket)) To hoListenSock
    If (Not(IsComObjectCreated(hoListenSock))) Begin
        Send CreateComObject of hoListenSock
    End

    Get ComBindAndListen Of hoListenSock 5555 25 To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoListenSock To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the next incoming connection
    // Wait a maximum of 20 seconds (20000 millisec)

    Get ComAcceptNextConnection Of hoListenSock 20000 To vRcvSock
    If (IsComObject(vRcvSock)) Begin
        Get Create (RefClass(cComChilkatSocket)) To hoRcvSock
        Set pvComObject Of hoRcvSock To vRcvSock
    End
    Get ComLastMethodSuccess Of hoListenSock To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoListenSock To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The sender will first send the big-endian integer for the number of bytes
    // that are forthcoming..
    Get ComReceiveInt32 Of hoRcvSock iBBigEndian To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRcvSock To sTemp1
        Showln sTemp1
        Send Destroy of hoRcvSock
        Procedure_Return
    End

    Get ComReceivedInt Of hoRcvSock To iNumBytesComing

    // Receive that many bytes..
    Get Create (RefClass(cComChilkatBinData)) To hoBdReceived
    If (Not(IsComObjectCreated(hoBdReceived))) Begin
        Send CreateComObject of hoBdReceived
    End
    Get pvComObject of hoBdReceived to vBdReceived
    Get ComReceiveBdN Of hoRcvSock iNumBytesComing vBdReceived To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRcvSock To sTemp1
        Showln sTemp1
        Send Destroy of hoRcvSock
        Procedure_Return
    End

    // Acknowledge the sender by sending back the number of bytes we received.
    Get ComNumBytes Of hoBdReceived To iTemp1
    Get ComSendInt32 Of hoRcvSock iTemp1 iBBigEndian To iSuccess

    // Close the connection.
    Move 20 To iMaxWaitMs
    Get ComClose Of hoRcvSock iMaxWaitMs To iSuccess
    Send Destroy of hoRcvSock

    // Save the received data to a file.
    Get ComWriteFile Of hoBdReceived "somePath/someFile.dat" To iSuccess
    // Assume success for the example...

    Showln "File received!"


End_Procedure