What do you want? a function that is called every time you read or update any field?
The old Clipper had a third party program called DBlog. Every time a dbf in an array list was edited it saved a copy of the record to a second folder\dbf. I believe it is posible but you would need to write it your self.
make a function that would be used in place of update dbf->field to dbf->(function(action,field,value))