The next set of functions involves changing records in an RMSfile. Until now,
the functions were only retrieving data from RMSfiles, but RMS also has functions
to add, change and delete records. Their names are dinsert(C-3), dupdate(C-3),
and ddelete(C-3) respectively. Dupdate and ddelete operate
only if there is a current record. This means that the call that precedes the
dupdate or ddelete must have accessed a record. The functions
that do this are: all the find functions, dinsert, dupdate, dreadc,
dread, and dwrite. Notice that ddelete is not included
in this list. Ddelete makes the current record inactive and no longer
accessible.