Rake task to convert gists from one format to another

convert_gists.rb

desc "Convert old gist tags into new format"
task :convert_gists, :dir do |t, args|
  puts ">>> !! Please provide a directory, eg. rake convert_gists[source/_new_posts]" unless args.dir
  if args.dir
    if args.dir == "/"
      dir = ""
    else
      dir = args.dir.sub(/(\/*)(.+)/, "\\2").sub(/\/$/, '');
    end
    Dir.open dir do |d|
      d.each do |file|
        next if file == '.' or file == '..'
        file_location = File.join(dir, file)
        text = File.read(file_location)
        new_text = text.gsub(/\[gist id\=(\"?)(\d*)(\"?)\]/, '{% gist \2 %}') # [gist id=1234567] => {% gist 1234567 %}
        File.open(file_location, "w") { |f| f.puts new_text }
      end
    end
  end
end