Derivation: FILE HISTory

FILEHIST specifies whether to allow the file definition of a file referred to by a ddname to be changed during runtime. This option is intended for use with applications called by Fortran that reallocate Fortran's supplied DD names.

Non-CICS default

FILEHIST=((ON),OVR)

CICS® default

FILEHIST is ignored under CICS.

Syntax

                      .-ON--.        .-OVR----.      
>>-FILEHIST--=--(--(--+-OFF-+--)--,--+-NONOVR-+--)-------------><

ON

Causes the history of a file to be used in determining its existence. It checks to see whether:

• The file was ever internally opened (in which case it exists)
• The file was deleted by a CLOSE statement (in which case it does not exist).

OFF

Causes the history of a file to be disregarded in determining its existence.

If you specify FILEHIST(OFF), you should consider:

• If you change file definitions during runtime, the file is treated as if it were being opened for the first time. Before the file definition can be changed, the existing file must be closed.
• If you do not change file definitions during runtime, you must use STATUS='NEW' to re-open an empty file that has been closed with STATUS='KEEP', because the file does not appear to exist to Fortran.

OVR

Specifies that the option can be overridden.

NONOVR

Specifies that the option cannot be overridden.