GNU Info

(gdbm.info)Fetch

---

Next: Delete Prev: Store Up: Top

---

Enter node , (file) or (file)node

Searching for records in the database.
**************************************

   Looks up a given `key' and returns the information associated with
that key. The pointer in the structure that is  returned is a pointer
to dynamically allocated memory block. To search for some data:

     content = gdbm_fetch(dbf, key);

   The parameters are:

GDBM_FILE dbf
     The pointer returned by `gdbm_open'.

datum key
     The `key' data.

   The datum returned in `content' is a pointer to the data found. If
the dptr is NULL, no data was found. If dptr is not NULL, then it points
to data allocated by malloc. `gdbm' does not automatically free this
data.  The user must free this storage when done using it. This
eliminates the need to copy the result to save it for later use (you
just save the pointer).

   You may also search for a particular key without retrieving it,
using:

     ret = gdbm_exists(dbf, key);

   The parameters are:

GDBM_FILE dbf
     The pointer returned by `gdbm_open'.

datum key
     The `key' data.

   Unlike `gdbm_fetch', this routine does not allocate any memory, and
simply returns true or false, depending on whether the `key' exists, or
not.