module Utils::IRB::Shell

def capture_output(with_stderr = false)
  return "missing block" unless block_given?
  require 'tempfile'
  begin
    old_stdout, $stdout = $stdout, Tempfile.new('irb')
    if with_stderr
      old_stderr, $stderr = $stderr, $stdout
    end
    yield
  ensure
    $stdout, temp = old_stdout, $stdout
    with_stderr and $stderr = old_stderr
  end
  temp.rewind
  temp.read
end