# File lib/compass/commands/sprite.rb, line 40
      def perform
        relative_uri = options[:uri].gsub(/^#{Compass.configuration.images_dir}\//, '')
        sprites = Compass::SpriteImporter.new(:uri => relative_uri, :options => Compass.sass_engine_options)
        options[:output_file] ||= File.join(Compass.configuration.sass_path, "sprites", "_#{sprites.name}.#{Compass.configuration.preferred_syntax}")
        options[:skip_overrides] ||= false
        contents = sprites.content_for_images(options[:skip_overrides])
        if options[:output_file][-4..-1] != "scss"
          contents = Sass::Engine.new(contents, Compass.sass_engine_options.merge(:syntax => :scss)).to_tree.to_sass
        end
        directory File.dirname(options[:output_file])
        write_file options[:output_file], contents
      end