[SOLVED] Cannot download multiple files

[T-Bird]

I have files that need to be downloaded only if the user has the correct password, thus I'm using the standard readfile() based download method as seen in example 1 of php.net's readfile manual.

 

if (file_exists($file)) {
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename='.basename($file));
    header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Pragma: public');
    header('Content-Length: ' . filesize($file));
    ob_clean();
    flush();
    readfile($file);
    exit;
}

 

The files I'm trying to transfer are on average 80MB zip files stored on the same box that is running the scripts.

 

I have two problems which I think are related... but may not be.

 

a) The user submits the password and it takes approximately a minute for the save dialogue box to appear.  PHP logs a timeout error, but the file downloads fine.

 

b) With files less than 60MB I can download several files at a time no sweat.  With files over 60MB in size I can only download one file at a time.  Anyone who tries to download the file while a transfer is in progress gets an empty placeholder file.

 

I tried switching to a chunked transfer method.  I got a code out of the comments on the php.net site that seemed promising and tried it.

 

function readfile_chunked($filename,$retbytes=true) {
   $chunksize = 1*(1024*1024); // how many bytes per chunk
   $buffer = '';
   $cnt =0;
   // $handle = fopen($filename, 'rb');
   $handle = fopen($filename, 'rb');
   if ($handle === false) {
       return false;
   }
   while (!feof($handle)) {
       $buffer = fread($handle, $chunksize);
       echo $buffer;
       ob_flush();
       flush();
       if ($retbytes) {
           $cnt += strlen($buffer);
       }
   }
       $status = fclose($handle);
   if ($retbytes && $status) {
       return $cnt; // return num. bytes delivered like readfile() does.
   }
   return $status;

} 

 

This solved problem-a as data immediately started to transfer to the browser.  I didn't get to test if it solved problem-b because after aprox 25-30 seconds php again (understandably) logged the timeout error and the transfer died.

 

Any clue why php is refusing to allow multiple downloads on code a?  Is there a way I can adjust PHP's timeout for only ONE page so that I can use code B without having all my pages use an ugly 1hour timeout?

 

Any other suggestions?

[MadTechie]

void set_time_limit  ( int $seconds  )

seconds

The maximum execution time, in seconds. If set to zero, no time limit is imposed.

 

so just add

set_time_limit(0);

to code B

[T-Bird]

Awesome.  Worked great.  I feel a little dense though.