用php中的header下載大檔案的方法

 先加入@ob_end_flush();釋放記憶體，
 在把輸出方式改為一行行讀取並輸出:
 while (!feof($handle)) {
  $string= fgets($handle, 4096);
  echo $string;
 }
就可以
例子:
 

1. $handle = fopen($csv_data_dir.$csvname_new,"r"); // 開啟檔案
2.  //$string=fread($handle, filesize($csv_data_dir.$csvname_new));
3.  $string='';
4.  header("Pragma:   public");
5.  header("Expires:   0");
6.  header("Cache-Control:   must-revalidate,   post-check=0,   pre-check=0");
7.  header("Content-Type:   application/octet-stream");
8.  header("Content-Disposition:   attachment;   filename=$csvname_new");
9.  header("Content-Transfer-Encoding:   binary");
10.  header("Content-Length:   ".filesize($csv_data_dir.$csvname_new));
11.  @ob_end_flush();
12.  while (!feof($handle)) {
13.   $string= fgets($handle, 4096);
14.   echo $string;
15.  }
16.  fclose($handle);
17.  exit;