Close files that are logically closed but physically open
The CLEAR FCACHE command physically closes any files that are logically closed but physically open due to the use of SET FCACHE ON. SET FCACHE ON speeds up program execution by leaving files physically open, thereby eliminating the involvement of the operating system when re-opening a file.
Normally this command should not be needed as files should be removed from the open file cache when an open request conflicts with the file's current status, for example, shared versus exclusive or update versus read-only.
// Program to tidy up on exit of application clear fcache