SAMPLE: GetVers.exe Specifies Component FileVersion and #Version

   <OBJECT ID="BoomButton" WIDTH=225 HEIGHT=35
   CLASSID="CLSID:56F1BF40-B2D0-11d0-A6D6-00AA00A70FC2"
   CODEBASE="http://example.microsoft.com/AControl.cab#Version=1,0,0,1">
   ...</OBJECT>
				

   Check the Registry for CLSID
   If CLSID of OBJECT is NOT found in the registry
      Download OBJECT
   Else If no #Version specified in CODEBASE tag
      Use OBJECT installed on system
   Else
      Check InprocServer32 key for location of installed component
      If File version of installed component < CODEBASE #Version Tag
         Download OBJECT
				

   [mfc42.dll]
   FileVersion=4,2,0,6256
   hook=mfc42installer
				

   Search for mfc42.dll in the system (first looking at the same directory
   as the previous version of the control being installed; if not found,
   the file is searched for via the standard search path for DLLs)
   If mfc42.dll is not found,
      install mfc42.dll
   Else
    Compare the file version of the DLL with the FileVersion keyword
    specified in the .inf file
				

   void reportError()
   {
       LPVOID lpMsgBuf;

       FormatMessage(
           FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
           NULL,
           GetLastError(),
           MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
           (LPTSTR) &lpMsgBuf,
           0,
           NULL );

       cout << (char*)lpMsgBuf << "\n";

       // Free the buffer.
       LocalFree( lpMsgBuf );
   }

   void main( int argc, char *argv[ ], char *envp[ ] )
   {
       cout << "\n";

       if(2 != argc)
       {
           cout << "Syntax: GetVer <File Name>\n";
           return;
       }

       DWORD dwArg;
       DWORD dwInfoSize = GetFileVersionInfoSize(argv[1], &dwArg;);

       if(0 == dwInfoSize)
       {
           cout << "No version info available\n";
           reportError();
           return;
       }

       BYTE* lpBuff = new BYTE[dwInfoSize];

       if(!lpBuff)
       {
           cout << "Out of Memory\n";
           return;
       }

       if(0 == GetFileVersionInfo(argv[1], 0, dwInfoSize, lpBuff))
       {
           cout << "Error retrieving version info\n";
           reportError();
           return;
       }

       VS_FIXEDFILEINFO *vInfo;

       UINT uInfoSize;

       if(0 == VerQueryValue(lpBuff, TEXT("\\"),
               (LPVOID*)&vInfo,
               &uInfoSize))
       {
           cout << "Version information not available\n";
           delete lpBuff;
           return;
       }

       if(0 == uInfoSize)
       {
           cout << "Version information not available\n";
           delete lpBuff;
           return;
       }

       cout << argv[1]
           << " Version: "
           << HIWORD(vInfo->dwFileVersionMS) << ","
           << LOWORD(vInfo->dwFileVersionMS) << ","
           << HIWORD(vInfo->dwFileVersionLS) << ","
           << LOWORD(vInfo->dwFileVersionLS) << "\n";

       delete lpBuff;
   }