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V_PTR()
Return the absolute offset (file pointer) of data stored in a DBV file
-------------------------------------------------------------------------------
Syntax
V_PTR( <cPointer> ) -> nOffset
Arguments
<cPointer> is a six byte pointer-field (FlexFile's version of a
memo-field).
Returns
V_PTR() returns the absolute offset of data pointed to by
<cPointer> in the DBV file associated with <cPointer>.
Description
For those who use Clipper's FOPEN() class of functions and who
would like direct access to the data in a DBV type file, FlexFile
provides V_PTR(). However, it is far safer to use V_RETRIEVE() and
V_POKE().
It must be noted that extreme care should be exercised when
writing data into the DBV file. You should never write data that
begins before V_PTR() or data which extends beyond V_LEN().
+------------------------- WARNING ---------------------------+
| Extreme care must be taken when using FWRITE() on a DBV |
| type file. Overwriting the bounds of a VLF by one byte can |
| corrupt the entire file. |
+-------------------------------------------------------------+
Examples
// Open a DBF file and its related DBV file.
USE dbf_file
V_USE( "dbv_file" )
? V_PTR( vlf ) // Result if the data related to vlf
// is 11,222 bytes from the beginning
// of dbv_file.dbv: 11222
See Also:
V_RETRIEVE()
V_POKE()
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