class Sass::Exec::Generic

def process_result

so they can run their respective programs.
This is meant to be overridden by subclasses

to appropriate IO streams.
(and `@options[:sourcemap]` if one has been specified)
In particular, sets `@options[:input]` and `@options[:output]`
Processes the options set by the command-line arguments. 
def process_result
  input, output = @options[:input], @options[:output]
  args = @args.dup
  input ||=
    begin
      filename = args.shift
      @options[:filename] = filename
      open_file(filename) || $stdin
    end
  @options[:output_filename] = args.shift
  output ||= @options[:output_filename] || $stdout
  if @options[:sourcemap] && @options[:output_filename]
    @options[:sourcemap_filename] = Util.sourcemap_name(@options[:output_filename])
  end
  @options[:input], @options[:output] = input, output
end