HOWTO: Determine the Version of a Microsoft Excel Workbook

• Microsoft Visual C++, 32-bit Editions, versions 5.0, 6.0
• Microsoft Excel 97 for Windows
• Microsoft Excel for Windows 95, versions 7.0, 7.0a
• Microsoft Excel for Windows, versions 5.0, 5.0a, 5.0c

SUMMARY

This article demonstrates how to determine the version of a Microsoft Excel Workbook (.xls).

MORE INFORMATION

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)
//*
//*        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"); 

REFERENCES

Microsoft Visual C++ Help, version 5.0; search on "structured storage"

Microsoft Developers Network (MSDN); search on "structured storage", "Microsoft Excel file format", "BOF", "beginning of file"

Microsoft Excel 97 Developer's Kit (ISBN: 1-57231-498-2); search on "Microsoft Excel file format", "BOF", "beginning of file"

Additional query words: excel97 excel8 xl5en32

Keywords : kbole kbExcel kbVC500 kbVC600 kbSDKExcel kbExcel97 kbDSupport
Version : WINDOWS:5.0,5.0a,5.0c,7.0,7.0a; winnt:5.0,6.0
Platform : WINDOWS winnt
Issue type : kbhowto