3.10 An Exercise

only for RuBoard

The chapter is "officially" over (wink, wink). The following two listings are only an exercise. Example 3-16 contains a remote debugging console. This console window can run on any computer on your network (or it can run on your only computer if you are processor-challenged). It just sits there, waiting for messages from the RemoteDebug class, which is shown in Example 3-17. To run the remote debug console, compile Example 3-16 and type the following code on the command line:

 C:\>listener 1969 

This line causes the remote console to wait for messages on port 1969.

Example 3-16 can be compiled from the command line as follows :

 vbc /t:exe /r:system.dll listener.vb 

Example 3-17 contains the listing for the RemoteDebug class, which sends messages to the remote debug console. It also contains a small test class so you can compile the class to an executable and test it. Once the remote debug console is started, you have to open up a second console window to run the executable containing the RemoteDebug class ( assuming you are testing and listening on the same machine).

Example 3-17, however, wires the remote debug class into the Log example from Example 3-9 earlier in the chapter. It can be compiled the same way as Example 3-16.

Example 3-16. Remote debug console

 'references: system.dll     Imports System Imports System.Net Imports System.Net.Sockets Imports System.Text     Public Class Listener   Implements IDisposable       Private port As Integer   Private myListener As TcpListener   Private mySocket As Socket   Private disposed As Boolean       Public Sub New(ByVal port As Integer)     Me.port = port     myListener = New TcpListener(port)   End Sub       Public Sub Listen( )         Dim buffer(1024) As Byte         Dim bytes As Integer     Dim ASCII As Encoding = Encoding.ASCII         'Start the listener     myListener.Start( )         'Wait for a connection     mySocket = myListener.AcceptSocket( )         myListener.Stop( )         'Read incoming bytes and convert to an ASCII     'string     bytes = mySocket.Receive(buffer, buffer.Length, 0)         Do While (bytes > 0)       Dim msg As String       msg = ASCII.GetString(buffer, 0, bytes)       Console.WriteLine(msg)       bytes = mySocket.Receive(buffer, buffer.Length, 0)     Loop         mySocket.Close( )       End Sub       Protected Overridable Sub DoDispose( )     mySocket.Close( )     MyListener.Stop( )     GC.SuppressFinalize(Me)   End Sub       Public Sub Dispose( ) Implements IDisposable.Dispose     Dispose(True)     GC.SuppressFinalize(Me)   End Sub       Protected Sub CheckDispose( )     If (disposed) Then       Throw New ObjectDisposedException( _           "RemoteDebug has been disposed.")     End If   End Sub       Protected Sub Dispose(ByVal disposing As Boolean)     If Not disposed Then       disposed = True       If (disposing) Then         DoDispose( )       End If     End If   End Sub       Public Sub Close( )     Dispose( )   End Sub       Protected Overrides Sub Finalize( )     Close( )   End Sub     End Class     Public Class Application       Public Shared Sub Main(ByVal args( ) As String)     If args.Length > 1 Then       Dim port As Integer = Convert.ToInt32(args(1))       Console.WriteLine("Listening on port {0}", port.ToString( ))       Dim myListener As New Listener(port)       While (True)         myListener.Listen( )       End While     Else       Console.WriteLine("USAGE: listen <port number>")     End If   End Sub     End Class 

Example 3-17. RemoteDebug class

 'references: system.dll     Imports System Imports System.Net Imports System.Net.Sockets Imports System.Text     Public Class RemoteDebug   Implements IDisposable       Private remoteServer As IPAddress   Private endPoint As IPEndPoint   Private sock As Socket   Private ASCII As Encoding   Private disposed As Boolean       Public Sub New(ByVal server As String, ByVal port As Integer)     ASCII = Encoding.ASCII     remoteServer = Dns.Resolve(server).AddressList(0)     EndPoint = New IPEndPoint(remoteServer, port)     'Create the Socket for sending data over TCP     sock = New Socket(AddressFamily.InterNetwork, _                       SocketType.Stream, _                       ProtocolType.Tcp)     sock.Connect(EndPoint)   End Sub       Public Sub Write(ByVal msg As String)     CheckDispose( )     If sock.Connected Then       Dim buffer( ) As Byte = ASCII.GetBytes(msg)       sock.Send(buffer, buffer.Length, 0)     End If   End Sub       Public Sub Dispose( ) Implements IDisposable.Dispose     Dispose(True)     GC.SuppressFinalize(Me)   End Sub       Protected Overridable Sub DoDispose( )     sock.Shutdown(SocketShutdown.Send)     sock.Close( )     GC.SuppressFinalize(Me)   End Sub       Protected Sub CheckDispose( )     If (disposed) Then       Throw New ObjectDisposedException( _           "RemoteDebug has been disposed.")     End If   End Sub       Protected Sub Dispose(ByVal disposing As Boolean)     If Not disposed Then       disposed = True       If (disposing) Then         DoDispose( )       End If     End If   End Sub       Public Sub Close( )     Dispose( )   End Sub       Protected Overrides Sub Finalize( )     Close( )   End Sub     End Class     Public Class Test       Public Shared Sub Main( )     Dim dbg As New RemoteDebug("localhost", 1969)     dbg.Write("This is a test")     dbg.Close( )   End Sub     End Class 

only for RuBoard