Go to the previous, next section.

Inserting and replacing records in the database.

The function gdbm_store inserts or replaces records in the database.

ret = gdbm_store(dbf, key, content, flag);

The parameters are:

The pointer returned by gdbm_open.
datum key
The key data.
datum content
The data to be associated with the key.
int flag
Defines the action to take when the key is already in the database. The value GDBM_REPLACE (defined in gdbm.h) asks that the old data be replaced by the new content. The value GDBM_INSERT asks that an error be returned and no action taken if the key already exists.

The values returned in ret are:

The item was not stored in the database because the caller was not an official writer or either key or content have a NULL dptr field. Both key and content must have the dptr field be a non-NULL value. Since a NULL dptr field is used by other functions to indicate an error, a NULL field cannot be valid data.
The item was not stored because the argument flag was GDBM_INSERT and the key was already in the database.
No error. content is keyed by key. The file on disk is updated to reflect the structure of the new database before returning from this function.

If you store data for a key that is already in the data base, gdbm replaces the old data with the new data if called with GDBM_REPLACE. You do not get two data items for the same key and you do not get an error from gdbm_store.

The size in gdbm is not restricted like dbm or ndbm. Your data can be as large as you want.

Go to the previous, next section.