Windows IPC

/*
==========================================================================

Purpose:

This is a sample code that demonstrates for the following:

* Using a Named Pipe as a server

Notes:

* 

Author:

* Swarajya Pendharkar

Date:

* 6th April 2006

Updates:

* 
                      
==========================================================================
*/

#include "stdafx.h"
#include "windows.h"

#define g_szPipeName "\\\\.\\Pipe\\MyNamedPipe"  //Name given to the pipe
//Pipe name format - \\.\pipe\pipename

#define BUFFER_SIZE 1024 //1k
#define ACK_MESG_RECV "Message received successfully"

int main(int argc, char* argv[])
{
     HANDLE hPipe;
     
     hPipe = CreateNamedPipe( 
          g_szPipeName,             // pipe name 
          PIPE_ACCESS_DUPLEX,       // read/write access 
          PIPE_TYPE_MESSAGE |       // message type pipe 
          PIPE_READMODE_MESSAGE |   // message-read mode 
          PIPE_WAIT,                // blocking mode 
          PIPE_UNLIMITED_INSTANCES, // max. instances  
          BUFFER_SIZE,              // output buffer size 
          BUFFER_SIZE,              // input buffer size 
          NMPWAIT_USE_DEFAULT_WAIT, // client time-out 
          NULL);                    // default security attribute 
     
     if (INVALID_HANDLE_VALUE == hPipe) 
     {
          printf("\nError occurred while creating the pipe: %d", GetLastError()); 
          return 1;  //Error
     }
     else
     {
          printf("\nCreateNamedPipe() was successful.");
     }
     
     printf("\nWaiting for client connection...");
     
     //Wait for the client to connect
     BOOL bClientConnected = ConnectNamedPipe(hPipe, NULL);
     
     if (FALSE == bClientConnected)
     {
          printf("\nError occurred while connecting to the client: %d", GetLastError()); 
          CloseHandle(hPipe);
          return 1;  //Error
     }
     else
     {
          printf("\nConnectNamedPipe() was successful.");
     }
     
     char szBuffer[BUFFER_SIZE];
     DWORD cbBytes;
     
     //We are connected to the client.
     //To communicate with the client we will use ReadFile()/WriteFile() 
     //on the pipe handle - hPipe
     
     //Read client message
     BOOL bResult = ReadFile( 
          hPipe,                // handle to pipe 
          szBuffer,             // buffer to receive data 
          sizeof(szBuffer),     // size of buffer 
          &cbBytes,             // number of bytes read 
          NULL);                // not overlapped I/O 
     
     if ( (!bResult) || (0 == cbBytes)) 
     {
          printf("\nError occurred while reading from the client: %d", GetLastError()); 
          CloseHandle(hPipe);
          return 1;  //Error
     }
     else
     {
          printf("\nReadFile() was successful.");
     }
     
     printf("\nClient sent the following message: %s", szBuffer);
     
     strcpy(szBuffer, ACK_MESG_RECV);
     
     //Reply to client
     bResult = WriteFile( 
          hPipe,                // handle to pipe 
          szBuffer,             // buffer to write from 
          strlen(szBuffer)+1,   // number of bytes to write, include the NULL 
          &cbBytes,             // number of bytes written 
          NULL);                // not overlapped I/O 
     
     if ( (!bResult) || (strlen(szBuffer)+1 != cbBytes))
     {
          printf("\nError occurred while writing to the client: %d", GetLastError()); 
          CloseHandle(hPipe);
          return 1;  //Error
     }
     else
     {
          printf("\nWriteFile() was successful.");
     }
     
     CloseHandle(hPipe);
     return 0; //Success
}