# File log4r/outputter/datefileoutputter.rb, line 47
    def initialize(_name, hash={})
      @DatePattern = (hash[:date_pattern] or hash['date_pattern'] or
                      DEFAULT_DATE_FMT)
      @DateStamp = Time.now.strftime( @DatePattern);
      _dirname = (hash[:dirname] or hash['dirname'])
      # hash[:dirname] masks hash[:filename]
      if _dirname
        if not FileTest.directory?( _dirname)
          raise StandardError, "'#{_dirname}' must be a valid directory", caller
        end
        @filebase = File.basename( $0, '.rb') + ".log"
      else
        @filebase = File.basename((hash[:filename] or hash['filename'] or ""))
      end
      hash['filename'] = File.join(_dirname,
                    @filebase.sub(/(\.\w*)$/, "_#{@DateStamp}" + '\1'))
      super(_name, hash)
    end