redirect.rb

require 'logger'
 
class TmpLog
  def write(message)
    logger.info(message)
  end
 
  private
 
    def logger
      @logger ||= Logger.new("/tmp/log")
    end
end

class Redirect
  def self.to(out, &block)
    back_out = $stdout
    $stdout = out
    yield
  ensure
    $stdout = back_out
  end
end
 
Redirect.to(TmpLog.new) {
  puts "TO /tmp/log"
}
Redirect.to(open('/dev/null', 'w')) {
  puts "TO /dev/null"
}
puts "TO STDOUT"