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Header Function

Return the length of the database file header.

Namespace:  XSharp.RT
Assembly:  XSharp.RT (in XSharp.RT.dll) Version: 2.10
Syntax
 FUNCTION Header() AS LONG
View Source

Return Value

Type: Int32
The number of bytes in the header of the database file.  If no database file is in use, Header() returns a 0.
Remarks
Header() is used with LastRec(), RecSize(), and DiskSpace() to create procedures for backing up files. By default, this function 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 or by calling the overload that accepts a workarea parameter (a workarea number or alias ).
Examples
This example determines the header size of the SALES.DBF:
X#
USE sales NEW
QOut(Header())                        // Result: 258
This example defines a pseudofunction, DBFSize(), that uses Header() with RecSize() and LastRec() to calculate the size of the current database file in bytes:
X#
define DBFSize() ((RecSize() * LastRec()) + Header() + 1)
Later you can use DBFSize() as you would any function:
X#
USE sales NEW
USE customer NEW
QOut(DBFSize())
QOut(Sales->DBFSize())
See Also