19ify.rb

#!/usr/bin/env ruby

ARGV.each do |file|
  data = File.read(file)
  if data
    if data =~ /\A\#\!ruby19/
      exit
    else
      puts "1.9ifying #{file}"
      File.open(file, "w") do |f|
        f.write("#!ruby19\n# encoding: utf-8\n\n")
        f.write(data)
      end
    end
  end
end