tdb(3) [centos man page]

TDB(3)                                                       Linux Programmer's Manual                                                      TDB(3)

NAME

       tdb - trivial database

SYNOPSIS

       A database similar to gdbm which allows multiple simultaneous writers.

DESCRIPTION

       This is a simple database API. It was inspired by the realisation that in Samba we have several ad-hoc bits of code that essentially imple-
       ment small databases for sharing structures between parts of Samba. As I was about to add another I realised that a generic database module
       was called for to replace all the ad-hoc bits.

       I based the interface on gdbm. I couldn't use gdbm as we need to be able to have multiple writers to the databases at one time.

AUTHORS

       Software: Andrew Tridgell <tridge@linuxcare.com> and Luke Kenneth Casson Leighton Man page: Ben Woodard <ben@valinux.com>

SEE ALSO

       gdbm(3),  tdb_open(3),  tdb_close(3),  tdb_delete(3),  tdb_error(3),  tdb_exists(3),  tdb_fetch(3), tdb_firstkey(3), tdb_store(3), tdb_tra-
       verse(3), tdb_lockall(3), tdb_lockkeys(3), tdb_chainlock(3)

Samba                                                              Aug 16, 2000                                                             TDB(3)

TDB_FIRSTKEY(3) 					     Linux Programmer's Manual						   TDB_FIRSTKEY(3)

NAME

       tdb_firstkey - return the key of the first record in a tdb database tdb_nextkey - return the key of next record in the tdb database

SYNOPSIS

       #include <tdb.h>

       TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb);
       TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA prev_key);

DESCRIPTION

       tdb_firstkey  fetches  the key of the first entry in the tdb database.  tdb_nextkey fetches the key of the entry immediately after prev_key
       in the database.

       The TDB_DATA structure returned by both these functions is defined as:

	      typedef struct {
		   char *dptr;
		   size_t dsize;
	      } TDB_DATA;

       The order in which this traverses the database is its own internal hash order. Do not expect the keys to  be  in  any  recognizably  sorted
       order.

       These  functions are reliable even if other writers are accessing the database (or you are replacing or deleting elements as you traverse),
       except in the case of nested tdb_firstkey or tdb_nextkey calls.	For example, the following outer traversal may fail to	traverse  all  the
       elements, or may even traverse elements twice if other processes are manipulating the database:

		   TDB_DATA i, j;

		   for (i = tdb_firstkey(tdb); i.dptr; i = tdb_nextkey(tdb, i)) {
			for (j = tdb_firstkey(tdb); j.dptr; j = tdb_nextkey(tdb, j)) {
			...
			}
		   }

       If such behaviour is desired, use tdb_traverse instead.

RETURN VALUE

       If  the	call  succeeds, then a TDB_DATA structure is returned with the dptr structure filled in. If the call fails or you have reached the
       end of the database then dptr will be set to NULL.

       NOTE: The caller is responsible for freeing the data pointed to by dptr

AUTHORS

       Software: Andrew Tridgell <tridge@linuxcare.com> and Luke Kenneth Casson Leighton Man page: Ben Woodard <ben@valinux.com>

SEE ALSO

       gdbm(3), tdb(3)

Samba								   Aug 16, 2000 						   TDB_FIRSTKEY(3)