After several applications have processed an NDF and recorded history information, the NDF's history component will contain a series of records, each identified by a date and time, which document its processing history.
You can determine how many such records exist, either with the general history enquiry routine NDF_HINFO, or more directly using the NDF_HNREC routine, thus:
CALL NDF_HNREC( INDF, NREC, STATUS )
The number of records is returned via the INTEGER argument NREC. Note that this value may (or may not) include a history record for the current application, depending on whether any history information has yet been written by it. The value may also be zero if no history information has ever been written.
Information about a particular record may be obtained by calling NDF_HINFO and supplying the record number.29 For example, if history recording has been in operation, you could obtain the name of the application which most recently modified an NDF as follows (the result is returned in the APPN variable):
INCLUDE 'NDF_PAR' CHARACTER * ( NDF__SZAPP ) APPN ... CALL NDF_HNREC( INDF, NREC, STATUS ) CALL NDF_HINFO( INDF, 'APPLICATION', NREC, APPN, STATUS )
Other information about individual records may also be obtained using
NDF_HINFO, such as the text width, the number of text lines written
and, of course, the date and time associated with the record (see
Appendix for full details of the
information items available).