how to run following mailslots program in VC++

Question

//writing to mailslot

#include <windows.h>
#include <stdio.h>

LPTSTR SlotName = TEXT("\\\\.\\mailslot\\sample_mailslot");

BOOL WriteSlot(HANDLE hSlot, LPTSTR lpszMessage)
{
   BOOL fResult; 
   DWORD cbWritten; 

   fResult = WriteFile(hSlot, 
     lpszMessage, 
     (DWORD) (lstrlen(lpszMessage)+1)*sizeof(TCHAR),  
     &cbWritten, 
     (LPOVERLAPPED) NULL); 

   if (!fResult) 
   { 
      printf("WriteFile failed with %d.\n", GetLastError()); 
      return FALSE; 
   } 

   printf("Slot written to successfully.\n"); 

   return TRUE;
}

int main()
{ 
   HANDLE hFile; 

   hFile = CreateFile(SlotName, 
     GENERIC_WRITE, 
     FILE_SHARE_READ,
     (LPSECURITY_ATTRIBUTES) NULL, 
     OPEN_EXISTING, 
     FILE_ATTRIBUTE_NORMAL, 
     (HANDLE) NULL); 

   if (hFile == INVALID_HANDLE_VALUE) 
   { 
      printf("CreateFile failed with %d.\n", GetLastError()); 
      return FALSE; 
   } 

   WriteSlot(hFile, TEXT("Message one for mailslot."));
   WriteSlot(hFile, TEXT("Message two for mailslot."));

   Sleep(5000);

   WriteSlot(hFile, TEXT("Message three for mailslot."));

   CloseHandle(hFile); 

   return TRUE;
}

 //reading from mailslot

#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <strsafe.h>

HANDLE hSlot;
LPTSTR SlotName = TEXT("\\\\.\\mailslot\\sample_mailslot");

BOOL ReadSlot() 
{ 
    DWORD cbMessage, cMessage, cbRead; 
    BOOL fResult; 
    LPTSTR lpszBuffer; 
    TCHAR achID[80]; 
    DWORD cAllMessages; 
    HANDLE hEvent;
    OVERLAPPED ov;

    cbMessage = cMessage = cbRead = 0; 

    hEvent = CreateEvent(NULL, FALSE, FALSE, TEXT("ExampleSlot"));
    if( NULL == hEvent )
        return FALSE;
    ov.Offset = 0;
    ov.OffsetHigh = 0;
    ov.hEvent = hEvent;

    fResult = GetMailslotInfo( hSlot, // mailslot handle 
        (LPDWORD) NULL,               // no maximum message size 
        &cbMessage,                   // size of next message 
        &cMessage,                    // number of messages 
        (LPDWORD) NULL);              // no read time-out 

    if (!fResult) 
    { 
        printf("GetMailslotInfo failed with %d.\n", GetLastError()); 
        return FALSE; 
    } 

    if (cbMessage == MAILSLOT_NO_MESSAGE) 
    { 
        printf("Waiting for a message...\n"); 
        return TRUE; 
    } 

    cAllMessages = cMessage; 

    while (cMessage != 0)  // retrieve all messages
    { 
        // Create a message-number string. 

        StringCchPrintf((LPTSTR) achID, 
            80,
            TEXT("\nMessage #%d of %d\n"), 
            cAllMessages - cMessage + 1, 
            cAllMessages); 

        // Allocate memory for the message. 

        lpszBuffer = (LPTSTR) GlobalAlloc(GPTR, 
            lstrlen((LPTSTR) achID)*sizeof(TCHAR) + cbMessage); 
        if( NULL == lpszBuffer )
            return FALSE;
        lpszBuffer[0] = '\0'; 

        fResult = ReadFile(hSlot, 
            lpszBuffer, 
            cbMessage, 
            &cbRead, 
            &ov); 

        if (!fResult) 
        { 
            printf("ReadFile failed with %d.\n", GetLastError()); 
            GlobalFree((HGLOBAL) lpszBuffer); 
            return FALSE; 
        } 

        // Concatenate the message and the message-number string. 

        StringCbCat(lpszBuffer, 
                    lstrlen((LPTSTR) achID)*sizeof(TCHAR)+cbMessage, 
                    (LPTSTR) achID); 

        // Display the message. 

        _tprintf(TEXT("Contents of the mailslot: %s\n"), lpszBuffer); 

        GlobalFree((HGLOBAL) lpszBuffer); 

        fResult = GetMailslotInfo(hSlot,  // mailslot handle 
            (LPDWORD) NULL,               // no maximum message size 
            &cbMessage,                   // size of next message 
            &cMessage,                    // number of messages 
            (LPDWORD) NULL);              // no read time-out 

        if (!fResult) 
        { 
            printf("GetMailslotInfo failed (%d)\n", GetLastError());
            return FALSE; 
        } 
    } 
    CloseHandle(hEvent);
    return TRUE; 
}

BOOL WINAPI MakeSlot(LPTSTR lpszSlotName) 
{ 
    hSlot = CreateMailslot(lpszSlotName, 
        0,                             // no maximum message size 
        MAILSLOT_WAIT_FOREVER,         // no time-out for operations 
        (LPSECURITY_ATTRIBUTES) NULL); // default security

    if (hSlot == INVALID_HANDLE_VALUE) 
    { 
        printf("CreateMailslot failed with %d\n", GetLastError());
        return FALSE; 
    } 
    return TRUE; 
}

void main()
{
   MakeSlot(SlotName);

   while(TRUE)
   {
      ReadSlot();
      Sleep(3000);
   }
}

Answer 1

Go through the Visual Studio C++ Guided Tour on MSDN or watch this introductory video explaining how to create a basic Win32 application in C++. They should be enough of a starting point. From there on just browse the MSDN library to advance your knowledge or search for issues you encounter.