http://api.rubyonrails.org/classes/ActionController/Base.html render :text => "error", :status => 500 render :text => "error", :status => :internal_server_error statusをシンボルで指定する場合は、lib/action_controller/status_code.rbを参照。 http://www.google.com/codesearch/p?hl=ja#m8Vht-lU3vE/vendor/rails/actionpack/lib/action_controller/status_codes.rb&q=file:status_codes.rb