traverse.rb

#! /usr/bin/ruby -w
# encoding: utf-8
#
def get_info(path)
  Info.new(path)
end

class Info
  def initialize(path)
    @path = path
    @stat = File::Stat.new(path)
  end
  attr_reader :path, :stat

  def <=>(op)
    self.stat <=> op.stat
  end

  def directory?
    @stat.directory?
  end
end

def get_useful_contents(path)
  Dir.entries(path).reject {|e| ['.', '..'].include?(e)}
end

def travarse(path, &order)
  names = get_useful_contents(path)
  contents = names.map { |e| path + '/' + e }.map { |e| get_info(e) }
  contents = contents.sort(&order).map do |e|
    if (e.directory? && e.path != path)
      e = travarse(e.path, &order)
    else
      e = [e]
    end
  end
  contents.flatten
end

dir = ARGV.shift
fail if dir.nil?

travarse(dir) {|a, b| a <=>b}.each do |e|
  p e.path
end