gistfile1.rb

require 'find'
require 'pathname'

class SharedFile
  attr_reader :file_name
  attr_reader :file_size
  
  def initialize(path, file_size)
    #@path = path
    @file_name = Pathname.new(path).basename
    @file_size = file_size
  end
  
  def ==(other)
    self.file_name == other.file_name && self.file_size == other.file_size
  end
  
  def eql?(other)
    self == other
  end

  def hash
    [file_name, file_size].hash
  end
 
end  

files = []
Find.find(".") do |path|
  files << SharedFile.new(path,File.size(path)) #if path =~ /.*\.pdf$/
end

results = files.group_by{|file| file}.map{|k,v| [k,v.count] }

# puts results[1].inspect

results.each do |result|
  puts "#{result[0].file_name}, #{result[0].file_size}, #{result[1]}" if result[1] > 1
end