How To Determine the Type of Handle Retrieved from OpenPrinter

SUMMARY

OpenPrinter returns a valid handle when a printer name or a server name is passed to it. Sometimes you might need to determine if the returned handle is a handle to a printer, because some Win32 spooler functions only accept printer handles and will fail on server handles. The following code determines if a handle is a printer handle:

   BOOL IsPrinterHandle( HANDLE hPrinter)
   {

       DWORD       cbNeeded;
       DWORD       Error;
       BOOL        bRet = TRUE;

       if( !GetPrinter(hPrinter, 2, (LPBYTE)NULL, 0, &cbNeeded ))
       {
           Error = GetLastError( );
        bRet = FALSE;

           if( Error == ERROR_INSUFFICIENT_BUFFER )
           {

             // Expect this for a valid printer handle.
                   bRet = TRUE;

           }

       }
       return bRet;

   }