Everything into one big text file

# Will read files and output into one big file with filename headers

def one_big_file (search_root)
    files = Dir[search_root + '/**/*']
    file_types = [".rb"]

    output_text = ""

    # Read File contents
    for i in 0...file_types.length
        file_type = files.select { |f|
            f.end_with?(file_types[i])
        }

        file_type.each { |f|
            file_text = File.read(Dir.pwd + "/" + f)
            output_text += ("=" * 80) + "\n" + f + "\n" + ("=" * 80) + "\n\n" + file_text + "\n\n"
        }
    end

    # Output to File
    output_file = File.open("./one_big_file.txt", "w")
    output_file.puts output_text
    output_file.close
end

search_root = ARGV[0]

if (search_root != nil)
    one_big_file(search_root)
else
    puts "Please have a search root as an argument.\nUse: \"FOLDER_NAME\" - with quotation marks\nDo not use \"./\" to begin path.\ni.e. ruby one_big_file.rb \"Tower Defence Game\""
end