Berkeley DB

DB→set_append_recno

						#include <db.h>
						int
						DB→set_append_recno(DB *,
						int (*db_append_recno_fcn)(DB *dbp, DBT *data, db_recno_t recno));
					

Description

When using the DB_APPEND option of the DB→put method, it may be useful to modify the stored data based on the generated key. If a callback function is specified using the DB→set_append_recno function, it will be called after the record number has been selected, but before the data has been stored. The callback function must return 0 on success and errno or a value outside of the Berkeley DB error name space on failure.

The called function must take three arguments: a reference to the enclosing database handle, the data DBT to be stored, and the selected record number. The called function may then ...