PHP offered download interrupted after X number of KB everytime

By | December 24, 2017

I have written a code that offers visitors to download a csv file which is of 1.1M in size. If one visits this script, download is interrupted around 30-40K (as shown below in wget output) while if he downloads it via a direct link like it works just fine. I believe this has something to do with php configuration values on the server but i have played almost with all values[relevant and non-relevant] such as

  • post_max_size [upto 90M]
  • max_file_upload [upto 90M]
  • max_execution_time [0 and upto 600]
  • max_input_time [0 and upto 600]
  • memory_limit [upto 1024M]

Following contains my code:


$size = intval(sprintf("%u", filesize($realpath)));

@ini_set('zlib.output_compression', 0);
header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");;
header("Content-Disposition: attachment;filename=events.xls"); 
header("Content-Transfer-Encoding: binary ");
header("Pragma: public");
header('Cache-Control: no-store, no-cache, must-revalidate'); 
header('Cache-Control: pre-check=0, post-check=0, max-age=0');
header ("Pragma: no-cache");
header("Expires: 0");
header("Content-Description: File Transfer");
header("Content-Type: text/csv");
header("Content-Length: ". $size);

// also tried with having a flush(); here
// also tried with file_get_contents();
//also tried with wrapping the file_get_contents() or readfile() call inside ob_start() and ob_flush()+ob_clean()


Here is the wget output

wget ""
--2011-06-26 19:47:55--
Connecting to||:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1139844 (1.1M) [text/csv]
Saving to: `test.php'

 3% [===>                                                                                                                            ] 36,373      --.-K/s   in 11s     

2011-06-26 19:48:11 (3.29 KB/s) - Connection closed at byte 36373. Retrying.

--2011-06-26 19:48:12--  (try: 2)
Connecting to||:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1139844 (1.1M) [text/csv]
Saving to: `test.php'

 3% [===>                                                                                                                            ] 40,469      --.-K/s   in 11s     

2011-06-26 19:48:24 (3.66 KB/s) - Connection closed at byte 40469. Retrying.

If i remove the header() required to offer a download and just echo the contents, then Chrome shows that the test.php was around 1.09M plus some more request, adds upto 1.1M[even in this case wget of test.php shows same behaviour as above], while firefox firebug shows that request was between 140K-300K[still not displaying all contents.


Check and search for: large. Copy-paste the code 🙂

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