Finds duplicate files and moves them to Trash.

duplicate_files.rb

#!/usr/bin/ruby

require 'digest'
require 'set'
require 'pathname'
require 'fileutils'

uniques   = Set.new
user      = `whoami`.sub("\n","")
trash     = Pathname.new("/Users/#{user}/.Trash/")
errors    = []

path = ARGV[0]
unless path
  puts "USAGE: ruby #{__FILE__} PATH"
  exit 1
end

directory = Pathname.new(path)
if !directory.directory?
  puts "ERROR: #{path} is not a directory"
  exit 1
end

Dir.foreach(directory) do |file|
  filename = Pathname.new(directory + file)
  next if filename.directory?

  md5 = Digest::MD5.file(filename).to_s
  FileUtils.mv(filename, trash) if uniques.include?(md5)
  uniques << md5
end

puts errors
exit 0