USED()
 Determine whether a database file is in USE
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 Syntax

     USED() --> lDbfOpen

 Returns

     USED() returns true (.T.) if there is a database file in USE; otherwise,
     it returns false (.F.).


 Description

     USED() is a database function that determines whether there is a
     database file in USE in a particular work area.  By default, USED()
     operates on the currently selected work area.  It will operate on an
     unselected work area if you specify it as part of an aliased expression.

 Examples

     .  This example determines whether a database file is in USE in
        the current work area:

        USE Customer NEW
        ? USED()               // Result: .T.
        CLOSE
        ? USED()               // Result: .F.

 Files   Library is CLIPPER.LIB.