rename.rb

#!/usr/bin/env ruby

ARGV[0] = ARGV[0] + "/" if ARGV[0][-1] != "/"
puts ":: Opening " + ARGV[0]

Dir.open( ARGV[0] ).each { |name|
  if name.include? ARGV[1] then
    r_name = name.gsub ARGV[1], ARGV[2]
    puts ":: Replacing " + name + " to " + r_name
    File.rename ARGV[0] + name, ARGV[0] + r_name
  end
}