def grep(pattern = '.*')
      regexp = Regexp.new(pattern)
      fetch_items_from_filesystem_or_zip
      @items = items.shift(2) + items.select {|i| i.name =~ regexp}
      sort_items_according_to_current_direction
      draw_items
      draw_total_items
      switch_page 0
      move_cursor 0
    end
def grep(pattern = '.*')
      regexp = Regexp.new(pattern)
      fetch_items_from_filesystem_or_zip
      @items = items.shift(2) + items.select {|i| i.name =~ regexp}
      sort_items_according_to_current_direction
      draw_items
      draw_total_items
      switch_page 0
      move_cursor 0
    end
Search files and directories from the current directory, and update the screen.

 * +pattern+ - Search pattern against file names in Ruby Regexp string.

 === Example

 a        : Search files that contains the letter "a" in their file name
 .*\.pdf$ : Search PDF files