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NTDB(3)                   System Administration tools                  NTDB(3)


NAME

       ntdb - A not-so trivial keyword/data database system


SYNOPSIS

       #include <ntdb.h>


DESCRIPTION

       If you have previously used the tdb library from Samba, much of this
       will seem familiar, but there are some API changes which a compiler
       will warn you about if you simply replace 'tdb' with 'ntdb' in your
       code! The on-disk format for ntdb is incompatible with tdb.

       tdb's API was based on gdbm, and ntdb continues this tradition, with
       enhancements. A differences guide is available in the text file
       lib/ntdb/doc/TDB_porting.txt in the SAMBA source tree.


NTDB API OVERVIEW

       The complete API is documented in the ntdb.h header, which is kept
       up-to-date and recommended reading.

       Normal usage is to call ntdb_open() to create or open an ntdb file.
       ntdb_store() is used to add records, ntdb_fetch() is used to fetch
       them. Traversals are supported via callback (ntdb_traverse()) or
       iteration (ntdb_firstkey() and ntdb_nextkey()). Transactions are
       supported for batching updates or reads atomically, using
       ntdb_transaction_start() and ntdb_transaction_commit().

   Use With Talloc
       ntdb_open() takes an optional linked list of attributes: in particular
       you can specify an alternate allocator (such as talloc):

           #include <talloc.h>
           #include <ntdb.h>

           static void *my_alloc(const void *owner, size_t len, void *priv)
           {
               return talloc_size(owner, len);
           }

           static void *my_expand(void *old, size_t newlen, void *priv)
           {
               return talloc_realloc_size(NULL, old, newlen);
           }

           static void my_free(void *old, void *priv)
           {
               talloc_free(old);
           }

           /* This opens an ntdb file as a talloc object with given parent. */
           struct ntdb_context *ntdb_open_talloc(const void *parent,
                                                 const char *filename)
           {
                struct ntdb_context *ntdb;
                union ntdb_attribute alloc;

                alloc.base.attr = NTDB_ATTRIBUTE_ALLOCATOR;
                alloc.base.next = NULL;
                alloc.alloc.alloc = my_alloc;
                alloc.alloc.expand = my_expand;
                alloc.alloc.free = my_free;

                ntdb = ntdb_open(filename, NTDB_DEFAULT, O_RDWR|O_CREAT, 0600,
                                 &alloc);
                if (ntdb) {
                    talloc_steal(parent, ntdb);
                    talloc_set_name(ntdb, "%s", filename);
                }
                return ntdb;
           }


SEE ALSO

       http://tdb.samba.org/


AUTHOR

       The original tdb software was created by Andrew Tridgell, and is now
       developed by the Samba Team as an Open Source project similar to the
       way the Linux kernel is developed. ntdb was derived from tdb, but
       mostly rewritten by Rusty Russell.

COPYRIGHT/LICENSE
       Copyright (C) Rusty Russell 2013, IBM Corporation

       This program is free software; you can redistribute it and/or modify it
       under the terms of the GNU Lesser General Public License as published
       by the Free Software Foundation; either version 3 of the License, or
       (at your option) any later version.

       This program is distributed in the hope that it will be useful, but
       WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
       General Public License for more details.

       You should have received a copy of the GNU General Public License along
       with this program; if not, see http://www.gnu.org/licenses/.

Samba 4.1                         03/12/2014                           NTDB(3)

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