What is your question?

Although NDBM_File is part of core, it isn't available on every platform , so you can use AnyDBM_File

C:\>perl -V:.*?dbm.*?
d_dbminitproto='undef';
i_dbm='undef';
i_gdbm='undef';
i_ndbm='undef';
i_rpcsvcdbm='define';
[download]

You can download the source for NDBM_File from http://public.activestate.com/pub/apc/perl-current/ext/NDBM_File/

http://perl5.git.perl.org/perl.git/tree/HEAD:/ext/NDBM_File