generate csv background

background_csv.rb

  def check_list
    file = Tempfile.new("scl")
    temp_siwake = ::TempSiwake.find(params[:id])
    output_csv_file_path = "fname.csv"

    pid = Process.fork {
      @rows = load_rows(params[:id])

      CSV.open(file.path, "w+") {|csv|
        @rows.each_with_index {|row, i|
          csv << row.fields_for_check
        }
      }
    }
    Process.waitpid(pid)

    send_csv file, output_csv_file_path, :ignore_iconv_error => true
  end