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 V_FILE2VLF()
 Copy a DOS file into a VLF
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 Syntax

    V_FILE2VLF(  <cFileName>,
                 <cOldPointer> )  ->     cNewPointer

 Arguments

    <cFileName> is the name of a disk file optionally including the
    path and drive designators.

    <cOldPointer> is a required six byte pointer-field or variable in
    which you have previously stored a pointer to variable length
    data. Passing six spaces causes FlexFile to assume that there is
    no old data to be released before the new <exp> data is saved.

 Returns

    V_FILE2VLF() returns a pointer which should be stored in the
    pointer- field with which the copied file is to be associated.

    V_FILE2VLF() returns (.F.) on error.  This causes the error system
    to be invoked with a "Data Type Mismatch".  Use V_ERROR() to fetch
    the specific error value (see Appendix B for a table of error
    descriptions).

    A typical error from this function is "File not found".  It is,
    therefore, the responsibility of the programmer to test for this
    condition before executing V_FILE2VLF().


 Description

    V_FILE2VLF() provides a mechanism for copying a DOS disk file into
    a VLF.  This is particularly handy in converting an application
    which has used Clipper's MEMOWRITE() function.

    V_FILE2VLF() is also handy for copying graphics images from disk
    files into a DBV file. When used in conjunction with V_VLF2FILE()
    a system can be implemented to handle graphics images which is
    compatible with the file based graphics systems such as DGE,
    SilverPaint, Flipper and the like.

    +-------------------------- WARNING --------------------------+ 
    | V_FILE2VLF() deletes the data associated with <cOldPointer> | 
    | before returning <cNewPointer>.  Attempting to use          | 
    | <cOldPointer> after this function deletes the data that it  | 
    | points to can corrupt the DBV file.                         | 
    +-------------------------------------------------------------+ 

 Notes

  . No additional memory is required to copy a file into a VLF. It
    is, therefore, possible to import a file larger than 65K
    (Clipper's variable size limit).

  . V_TYPE() will return "C" (character) for any VLF that has been
    created by V_FILE2VLF(). This implies that V_RETRIEVE() will
    return a character string.

 Examples

    // Open a DBF file and its related DBV file
    // The dbf_file has a 12 byte field called "exe_name"
    // and the usual 6 byte field called "vlf"
    USE dbf_file
    ZAP
    INDEX ON exe_name TO dbf_file
    V_USE( "dbv_file" )

    // This may seem silly, but lets store the Clipper compiler
    // in the DBV file.
    APPEND BLANK
    REPLACE exe_name WITH "CLIPPER.EXE"

    // This will copy the Clipper.exe into a VLF.
    REPLACE vlf WITH V_FILE2VLF( exe_name, vlf )

    // Later when we want to execute Clipper (you better have
    // lots of memory).
    SEEK "CLIPPER.EXE"
    ? V_VLF2FILE( "TEMP.EXE",  vlf )
    ? V_ERROR()

    RUN temp