get unique lines from files

gistfile1.rb

#!/usr/bin/env ruby

my_files = Dir.chdir(ARGV[0]) { Dir.glob("./*").map{|x| File.expand_path(x) } }

def my_array_steamer(oldarr, newfile)
	lines = (File.readlines(newfile)).map(&:strip)
	oldarr | lines
end

my_arr = Array.new
my_files.each do |x|
	my_arr = my_array_steamer(my_arr,x) 
end

File.open('temp.txt', 'w') {|f| f.puts(my_arr) }