with_db (bin/rsendmail.rb)

    # File bin/rsendmail.rb, line 92
    def with_db(name)
      require 'gdbm'
      begin
        db = nil
        begin
          db = GDBM::open(File.join("/home/matt/.rfilter/var", name), 0600)
        rescue Errno::EWOULDBLOCK
          # FIXME: only wait so long, then defer
          sleep(2)
          retry
        end
        yield db
      ensure
        db.close unless db.nil?
      end
    end