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 Export the contents of a binary large object (BLOB) pointer to a file
     Note:  A BLOB file (.dbv or .fpt) is used for storing memo field
     information as an alternative to the standard .dbt file mechanism
     supported by some RDDs.  It is a more powerful and efficient mechanism
     for storing and retrieving large amounts of data than using .dbt files.
     CA-Clipper supplies the DBFCDX driver, which uses the BLOB file storage
     mechanism by default, and the DBFMEMO driver, which you can use as a
     driver with a named super RDD (see MEMOSETSUPER()).  Refer to the RDD
     Features in the "Replaceable Database Driver Architecture" chapter of
     the Drivers Guide for further information on using this
     driver.BLOB:definitionBLOB:drivers supporting


     BLOBDirectExport(<nPointer>, <cTargetFile>, [<nMode>])
        --> lSuccess


     <nPointer> is a pointer to the BLOB data.  This pointer can be
     obtained using BLOBDIRECTPUT(), BLOBDIRECTEXPORT(), or

     <cTargetFile> is the name of the target file where the BLOB data
     will be written, including an optional drive, directory, and extension.
     See SETDEFAULT() and SETPATH() for file searching and creation rules.
     No default extension is assumed.

     If <cTargetFile> does not exist, it is created.  If it exists, this
     function attempts to open the file in exclusive mode and, if successful,
     the file is written to without warning or error.  If access is denied
     because another process is using the file, for example, NETERR() is set
     to true (.T.).  Concurrency control:and BLOBDIRECTEXPORT()

     <nMode> is a constant defining the copy mode, as shown in the table

     Copy Mode Constants
     Constant                 Description
     BLOB_EXPORT_APPEND       Appends to the file
     BLOB_EXPORT_OVERWRITE    Overwrites the file (this is the default)


     BLOBDIRECTEXPORT() returns true (.T.) if successful; otherwise, it
     returns false (.F.).


     By default, BLOBDIRECTEXPORT() operates on the currently selected work
     area.  It can be made to operate on an unselected work area by
     specifying it within an aliased expression.


     .  This example extracts an array of pointers from the BLOB
        file's root area, then uses one of the pointers to export a picture
        to a file:

           LOCAL cPixFile
           LOCAL nPointer
           LOCAL aBLOBPtrs

           cPixFile := "picture.gif"

           // Customer database with a picture of
           // each customer stored in a field called Pix
           USE Customer NEW VIA "DBFCDX"

           // Assumes that the program previously
           // stored an array of direct BLOB pointers
           // into the root area of the BLOB file.
           // The picture that we want is assumed to
           // be the second array element.
           aBLOBPtrs := BLOBROOTGET()
           nPointer := aBLOBPtrs[2]

           // Export picture pointed to by nPointer to a file
           IF !BLOBDirectExport(nPointer, cPixFile, ;
                 Alert("Export of picture " + cPixFile + ";
              // Code for displaying picture would go here

 Files   Library is CLIPPER.LIB.

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