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V_POKE()
Write character data into a character type VLF
-------------------------------------------------------------------------------
Syntax
V_POKE( <cPointer>,
<cData>,
[<nOffset>] )
Arguments
<cPointer> is a six byte pointer-field (FlexFile's version of a
memo-field).
<cData> is a character string to be written into the data pointed
to by <cPointer>. If the length of <cData> is greater than
V_LEN(<cPointer>) - <nOffset>, the data will be trucated.
<nOffset> is the offset within the data pointed to by <cPointer>
at which to begin writing <cData>. If not specified, <nOffset>
defaults to 1.
Returns
None.
Description
V_POKE() is used when you want to overwrite some or all of a
character type VLF. V_POKE() is different than V_STUFF() in that
it does not change or return <cPointer>. Instead, V_POKE()
modifies the data directly on the disk at its present location.
V_POKE() is different than V_REPLACE() in that it cannot extend
the length of the data pointed to by <cPointer> nor can it release
any space associated with <cPointer>.
Notes
. V_POKE() is most useful when you know that the new data is the
same length (or a subset) of the old data.
Examples
// Open a DBF and a related DBV file.
USE Main.dbf
V_USE( "Main.dbv" )
// Replace can store any length data.
APPEND BLANK
REPLACE vlf_fld WITH V_REPLACE( "ABCDEFGH", vlf_fld )
// Poke some data into the file.
V_POKE( vlf_fld, "test", 3 )
? V_RETRIEVE( vlf_fld )// Result: ABtestGH
// Try to write past the end of the fields current length.
V_POKE( vlf_fld, "You cannot do much harm", 3 )
? V_RETRIEVE( vlf_fld )// Result: ABYou ca
See Also:
V_REPLACE()
V_STUFF()
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