bsddb - mystery wrapped in enigma

Skip Montanaro skip at pobox.com
Mon Oct 1 14:53:22 CEST 2001


    d> I have been scouring the earth for a good tutorial on the bsddb
    d> module. Is there anything (in print or otherwise) lurking about that
    d> might help?

    d> I am trying to extract information from an existing berkeley db file 
    d> (sleepycat).

Assuming the version of the file you want to probe matches the version of
libdb you have installed, and you know what type of file it is (hash, btree
or recno), you should be able to just open it with the proper open function
and then treat it more or less like a dictionary.  To wit:

    % file /etc/mail/aliases.db
    /etc/mail/aliases.db: Berkeley DB (Hash, version 7, native byte-order)
    % python
    Python 2.1.1 (#6, Sep 24 2001, 09:14:11) 
    [GCC 3.0.1] on linux2
    Type "copyright", "credits" or "license" for more information.
    >>> import bsddb
    >>> dir(bsddb)
    ['__doc__', '__file__', '__name__', 'btopen', 'error', 'hashopen', 'rnopen']
    >>> db = bsddb.hashopen("/etc/mail/aliases.db")
    >>> db.keys()
    ['postmaster\x00', 'daemon\x00', 'ingres\x00', 'toor\x00', 'operator\x00', 'decode\x00', 'root\x00', '@\x00', 'mailer-daemon\x00', 'bin\x00', 'games\x00', 'nobody\x00', 'system\x00', 'uucp\x00', 'manager\x00', 'dumper\x00']
    >>> for k in db.keys():
    ...   print k, db[k]
    ... 
    postmaster root
    daemon root
    ingres root
    toor root
    operator root
    decode root
    root skip at pobox.com
    @ @
    mailer-daemon postmaster
    bin root
    games root
    nobody root
    system root
    uucp root
    manager root
    dumper root

Note that the open function (hashopen) must match the type of the file (Hash
in this case).

-- 
Skip Montanaro (skip at pobox.com)
http://www.mojam.com/
http://www.musi-cal.com/




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