gistfile1.rb

#!/usr/bin/env ruby
%w[rubygems sinatra jsmin cssmin].each{|l| require l}

configure :development do
  set :js_proc, proc {|f| "\n/* '#{f}' */\n" + File.read(f)}
  set :css_proc, proc {|f| "\n/* '#{f}' */\n" +File.read(f)}
end
configure :production do
  set :js_proc,
      proc{|f|"/* '#{File.basename(f)}' */\n" + JSMin.minify(File.read(f))}
  set :css_proc,
      proc{|f| "/* '#{File.basename(f)}' */\n"+ CSSMin.minify(File.read(f))}
end

def bundle(name, *files)
  # All the needed variables
  format = name.sub!(/.*\.(.*)$/, $1)
  file   = options.public + '/' + options.bundle

  # Now, we read each file and concatenate it in an array
  bundle = files.map { |f| options.public + "/#{f}.#{format}"} \
                .map { |f| options.send("#{format}_proc",f)  }.join("\n")

  # If it does not exist
  FileUtils.mkdir_p(File.dirname(file)
  File.open(file, 'a+').write(bundle)
end