How To Determine the Version of a Microsoft Excel Workbook (178605)

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Microsoft Excel saves data using structured storage. In particular, it creates a data stream called "Workbook" (previously just "Book") where it saves the contents starting with a BOF (beginning of file) record. This record contains useful attributes of the workbook, as well as the version. The following Microsoft Visual C++ code demonstrates how to open the file, read it, and return the version number based on the BOF.

1. Create a new "Win32 Console Application" in Microsoft Developer Studio.
2. Add a C++ Source File (.cpp) to the project and add the following code to the source file:

   #include <windows.h>
   #include <iostream.h>   // My additions
   
   // BOF record from Microsoft Excel
   typedef struct _xlbof
   {
      char bofMarker; // Should be 0x09
   
      char vers;  // Version indicator for biff2, biff3, and biff4
                  // = 0x00 -> Biff2
                  // = 0x02 -> Biff3
                  // = 0x04 -> Biff4
                  // = 0x08 -> Biff5/Biff7/Biff8
   
      char skip[2]; // Unspecified
   
      short int vers2;  // Version number
                        // 0x0500 -> Biff5/Biff7
                        // 0x0600 -> Biff8
   
      short int dt;     // Substream type (not used in this example)
   
      short int rupBuild;  // Internal build identifier
      short int rupYear;   // Internal Build year
   } XLBOF;
   
   
   
   //* XLVersionFromFile() ******************************************
   //* Returns
   //*        n for BiffN
   //*   i.e. 8 for Biff8 (Microsoft Excel 97, Excel 2000, Excel 2002)
   //*
   //*        Negative if an error occurs
   //****************************************************************
   
   int XLVersionFromFile(char *filename) {
      // Translate filename to Unicode
      WCHAR wcFilename[1024];
      int i = mbstowcs(wcFilename, filename, strlen(filename));
      wcFilename[i] = 0;
   
      IStorage *pStorage;
      HRESULT hr;
      XLBOF xlbof;
   
      // Open the document as an OLE compound document
      hr = ::StgOpenStorage(wcFilename, NULL,
                 STGM_READ | STGM_SHARE_EXCLUSIVE, NULL, 0, &pStorage);
   
      if(!FAILED(hr)) {
         // Open the data-stream where Microsoft Excel stores the data
         IStream *pStream;
         hr = pStorage->OpenStream(L"Workbook", NULL,
                 STGM_READ | STGM_SHARE_EXCLUSIVE, 0, &pStream);
   
         // If "Workbook" does not exist, try "Book"
         if(FAILED(hr)) {
            hr = pStorage->OpenStream(L"Book", NULL,
                 STGM_READ | STGM_SHARE_EXCLUSIVE, 0, &pStream);
         }
         if(!FAILED(hr)) {
            // Read the relevant BOF information
            DWORD dwCount; // bytes read
            pStream->Read(&xlbof, sizeof(XLBOF), &dwCount);
   
            // Let go of the IStream pointer
            pStream->Release();
         }
         else return -2;
   
         // Let go of the IStorage pointer
         pStorage->Release();
       }
       else return -1;
   
       // Determine which version to return
       if(xlbof.vers != 0x08) return (xlbof.vers + 4) / 2;
       else {
          switch(xlbof.vers2) {
            case 0x0500:  // Either Biff5 or Biff7
               // Biff7's rupYear is at least 1994
               if(xlbof.rupYear < 1994) return 5;
   
               // Check for specific builds of Microsoft Excel 5
               switch(xlbof.rupBuild) {
                  case 2412: // XL5a
                  case 3218: // XL5c
                  case 3321: // NT XL5
                     return 5;
                  default:
                     return 7;
               }
   
          case 0x0600:  return 8;
          }
       }
   
       // Version not recognized. Perhaps there is a newer version.
       return -3;
   }
   
   void main()
   {
      int iretVal = 0;
      iretVal = XLVersionFromFile("C:\\Test.xls");
                                  //Adapt the filename to your example
      cout << "The Excel Version is " << iretVal << "\n\n\r";
      return;
   }
   					

3. In the main()function, you may need to modify the path and filename of the Microsoft Excel workbook in the following line of code:

    iretVal = XLVersionFromFile("C:\\Test.xls");