Send a 4-byte Length Prefix over a Socket

See more Socket/SSL/TLS Examples

Demonstrates Socket.SendCount, which sends a four-byte length prefix in network byte order. This is typically used to tell the peer how many bytes follow.

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoSocket
    Boolean iBTls
    Integer iMaxWaitMs
    Integer iMessageLength
    String sTemp1

    Move False To iSuccess

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

    //  Connect to the server using TLS.
    Move True To iBTls
    Move 5000 To iMaxWaitMs
    Get ComConnect Of hoSocket "example.com" 5000 iBTls iMaxWaitMs To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Send a four-byte length prefix in network byte order.  A common framing pattern is to send the
    //  number of bytes in a message before the message itself, so the peer knows exactly how many bytes
    //  to read.
    Move 512 To iMessageLength
    Get ComSendCount Of hoSocket iMessageLength To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Length prefix sent."


End_Procedure