TeeIO: A method for logging to a file and STDOUT at the same time. Or to any two or more IOs. Greatly inspired by James Edward Grey II.

tee_io.rb

class TeeIO
  # TeeIO will write to each of these IOs when it is written to.
  def initialize(*ios)
    @ios = ios
  end

  def write(data)
    @ios.each { |io| io.write(data) }
  end

  def close
    @ios.each { |io| io.close }
  end
end

log_filename = Rails.root.join('log', 'doinstuff.txt')
file = open(log_filename, 'w')

Rails.logger = Logger.new(TeeIO.new($stdout, file))
Rails.logger.info "It works!"

file.close