Downloading large files reliably in PHP
download, php
Solution
Chunking files is the fastest / simplest method in PHP, if you can't or don't want to make use of something a bit more professional like cURL, `mod-xsendfile` on Apache or some dedicated script.
$filename = $filePath.$filename;
$chunksize = 5 * (1024 * 1024); //5 MB (= 5 242 880 bytes) per one chunk of file.
if(file_exists($filename))
{
set_time_limit(300);
$size = intval(sprintf("%u", filesize($filename)));
header('Content-Type: application/octet-stream');
header('Content-Transfer-Encoding: binary');
header('Content-Length: '.$size);
header('Content-Disposition: attachment;filename="'.basename($filename).'"');
if($size > $chunksize)
{
$handle = fopen($filename, 'rb');
while (!feof($handle))
{
print(@fread($handle, $chunksize));
ob_flush();
flush();
}
fclose($handle);
}
else readfile($path);
exit;
}
else echo 'File "'.$filename.'" does not exist!';
Ported from richnetapps.com / NeedBee. Tested on 200 MB files, on which `readfile()` died, even with maximum allowed memory limit set to `1G`, that is five times more than downloaded file size.
BTW: I tested this also on files `>2GB`, but PHP only managed to write first `2GB` of file and then broke the connection. File-related functions (fopen, fread, fseek) uses INT, so you ultimately hit the limit of `2GB`. Above mentioned solutions (i.e. `mod-xsendfile`) seems to be the only option in this case.
EDIT: Make yourself 100% that your file is saved in `utf-8`. If you omit that, downloaded files will be corrupted. This is, because this solutions uses `print` to push chunk of a file to a browser.
Problem
I have a php script on a server to send files to recipents: they get a unique link and then they can download large files. Sometimes there is a problem with the transfer and the file is corrupted or never finishes. I am wondering if there is a better way to send large files Code: ``` $f = fopen(DOWNLOAD_DIR.$database[$_REQUEST['fid']]['filePath'], 'r'); while(!feof($f)){ print fgets($f, 1024); } fclose($f); ``` I have seen functions such as ``` http_send_file http_send_data ``` But I am not sure if they will work. What is the best way to solve this problem? Regards erwing