ead/write operations to the data base.
<EM>Dbname</EM> is the name of the data base.
Actually, ndbm manager creates two files which have suffixes <TT>".pag"</TT>
and <TT>".dir"</TT>.
<EM>Mode</EM> specifies file-open mode; 0 for read-only access, 1 for write-only,
and 2 for read-write; also #x200 should be <EM>or</EM>ed when you create
the file  at the first time.
<EM>Flag</EM> gives access permission that is changed by chmod.
#o666 or #o664 is good for <EM>flag</EM>.
<B>Dbm-open</B> returns an integer that