php;">$fp = fopen('php://output', 'a');fputs($fp, 'strings');........fclose($fp)

 /**  * 文章訪問日志  * 下載的日志文件通常很大, 所以先設(shè)置csv相關(guān)的Header頭, 然后打開  * PHP output流, 漸進(jìn)式的往output流中寫入數(shù)據(jù), 寫到一定量后將系統(tǒng)緩沖沖刷到響應(yīng)中  * 避免緩沖溢出  */ public function articleAccessLog($timeStart, $timeEnd) {  set_time_limit(0);  $columns = [   '文章ID', '文章標(biāo)題', ......  ];  $csvFileName = '用戶日志' . $timeStart .'_'. $timeEnd . '.xlsx';  //設(shè)置好告訴瀏覽器要下載excel文件的headers  header('Content-Description: File Transfer');  header('Content-Type: application/vnd.ms-excel');  header('Content-Disposition: attachment; filename="'. $fileName .'"');  header('Expires: 0');  header('Cache-Control: must-revalidate');  header('Pragma: public');  $fp = fopen('php://output', 'a');//打開output流  mb_convert_variables('GBK', 'UTF-8', $columns);  fputcsv($fp, $columns);//將數(shù)據(jù)格式化為CSV格式并寫入到output流中  $accessNum = '1000000'//從數(shù)據(jù)庫獲取總量，假設(shè)是一百萬  $perSize = 1000;//每次查詢的條數(shù)  $pages = ceil($accessNum / $perSize);  $lastId = 0;  for($i = 1; $i <= $pages; $i++) {   $accessLog = $logService->getArticleAccessLog($timeStart, $timeEnd, $lastId, $perSize);   foreach($accessLog as $access) {    $rowData = [     ......//每一行的數(shù)據(jù)    ];    mb_convert_variables('GBK', 'UTF-8', $rowData);    fputcsv($fp, $rowData);    $lastId = $access->id;   }   unset($accessLog);//釋放變量的內(nèi)存   //刷新輸出緩沖到瀏覽器   ob_flush();   flush();//必須同時使用 ob_flush() 和flush() 函數(shù)來刷新輸出緩沖。  }  fclose($fp);  exit(); }