Michael E. Chancey Jr.

Interapplication Communication with Named Pipes

// December 13th, 2009 // Useful Code

Ever make two separate applications but need them to be able to send information back and forth. Say an Instant Messenger and a Business app which need direct integration between one another. Named pipes is a pretty simple solution to achieve this. .NET 3.5 has made this much simpler by including Named Pipes in its release, this used to be real nasty when trying to achieve this in any other language then C++.

//Application

---

using System;
using System.IO;
using System.IO.Pipes;

class Program
{
    /// <summary>
    /// MAIN APPLICATION THREAD
    /// </summary>
    /// <param name="args">NOTHING IS ACCEPTED HERE</param>
    static void Main(string[] args)
    {
        //HOLDS THE SECLECTION A USER MAKES AS TO WHAT THEY WANT TO RUN
        string tmpSelection = string.Empty;

        //ASK THE USER WHAT THEY WANT TO DO
        Console.Write("Please Enter A Selection 1(Server) or 2(Client): ");
        tmpSelection = Console.ReadLine();

        //CLEAR THE SCREEN AND BEGIN RUNNING THE USERS SELECTION
        Console.Clear();
        if (tmpSelection == "1")
        {
            //START A PIPE SERVER
            pipeServer();
        }
        else if (tmpSelection == "2")
        {
            //START A PIPE CLIENT
            pipeClient();
        }
        else
        {
            //LET THE USER KNOW THEY HAVE MADE AN INVALID SELECTION
            Console.WriteLine("Invalid selection made.  This app will now close.");
            Console.ReadLine();
        }
    }

    /// <summary>
    /// RUNS A PIPE CLIENT FOR SENDING MESSAGES
    /// </summary>
    private static void pipeClient()
    {
        //LET THE USER KNOW WHAT IS GOING ON
        Console.WriteLine("Starting Client!");

        //LOOP FOREVER FOR TESTING PURPOSES
        while (true)
        {
            //CREATE A CONNECTION TO A NAMED PIPE ON THE LOCAL MACHINE NAMED testPipe
            using (NamedPipeClientStream tmpPipe = new NamedPipeClientStream(".", "testPipe", PipeDirection.Out))
            {
                string tmpSendMessage;

                //GET SOME TEXT TO SEND THROUGH THE PIPE
                Console.Write("Enter Some Text To Send: ");
                tmpSendMessage = Console.ReadLine();

                //SEND THE MESSAGE THROUGH THE PIPE
                tmpPipe.Connect();
                using (TextWriter tmpWriter = new StreamWriter(tmpPipe))
                {
                    tmpWriter.WriteLine(tmpSendMessage);
                }
            }
        }
    }

    /// <summary>
    /// RUNS A PIPE SERVER FOR ACCEPTING MESSAGES
    /// </summary>
    private static void pipeServer()
    {
        //LET THE USER KNOW WHAT IS GOING ON
        Console.WriteLine("Starting Server!");

        //LOOP FOREVER FOR TESTING PURPOSES
        while (true)
        {
            //CREATE A NAMED PIPE ON THE LOCAL MACHINE NAMED testPipe
            using (NamedPipeServerStream tmpPipe = new NamedPipeServerStream("testPipe", PipeDirection.In))
            {
                //READ THE DATA ON THE PIPE
                tmpPipe.WaitForConnection();
                using (TextReader tmpReader = new StreamReader(tmpPipe))
                {
                    Console.WriteLine(tmpReader.ReadLine());
                }
            }
        }
    }
}