Eccube\Service\CsvExportService::fputcsv PHP Method

    public function fputcsv($row)
    {
        if (is_null($this->convertEncodingCallBack)) {
            $this->convertEncodingCallBack = $this->getConvertEncodhingCallback();
        }
        fputcsv($this->fp, array_map($this->convertEncodingCallBack, $row), $this->config['csv_export_separator']);
    }