Question

Small script, being used to send one of two .pdf files to the user based on the get string:

if ($fileToSend == "bigone") { 
   $filename = "largefile.pdf";
   $header = "application/pdf";
} else if ($fileToSend == "smallone") { 
   $filename = "smallfile.pdf";
   $header = "application/pdf";
}
if (file_exists('d/' . $filename)){
    header('Content-type: ' . $header);
    header('Content-disposition: attachment; filename=' . $filename);   
    readfile('d/' . $filename);
} else { 
    echo('No good');
}

Both files d/smallfile.pdf and d/largefile.pdf exist. smallfile.pdf is about 5megs. largefile.pdf is about 25megs.

sendFile.php?fileToSend=smallone works.

sendFile.php?fileToSend=bigone doesn’t work; in FF, it says

File not found
Firefox can’t find the file at [url]/sendFile.php?fileToSend=bigone

There are no filename errors.

I’ve tried

• Adding flush(); prior to the readfile; this causes the download file dialogue box to appear, but then serves a 0 byte file
• Adding flush(); prior to the readfile, and adding header(‘Content-Length: ‘ . filesize(‘d/’ . $filename)); – this works successfully, but takes close to 2 minutes to process (ie, once I hit the URL, nothing happens for close to 2 minutes, and then the dialogue box appears with the actual file to download in it correctly).

Any help would be much appreciated.
Jon

Answer 1

Yes your problem is most likely php timing out while feeding you the file, a remedy for this is to feed you chunks so as not to chew memory and set_time_limit(0); so it wont timeout after 60s:

 <?php 
 if(isset($_GET['fileToSend'])){

    switch($_GET['fileToSend']){
        case "bigone":
            if(downloadFile("./d/largefile.pdf")===false){
                //failed, do somthing
            }
            break;

        case "smallone":
            if(downloadFile("./d/smallfile.pdf")===false){
                //failed, do something
            }
            break;

        default:
            echo 'No file selected';
            break;

    }

 }

 function downloadFile($file){
    if (file_exists($file)) {
        if(is_dir($file)){return false;}
        header('Content-Description: File Transfer');
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename="'.basename($file)).'"';
        header('Content-Transfer-Encoding: binary');
        header('Connection: Keep-Alive');
        header('Expires: 0');
        header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
        header('Pragma: public');
        header('Content-Length: ' . filesize($file));

        ob_clean();
        $handle = fopen($file, "rb");
        $chunksize=(filesize($file)/1024);

        set_time_limit(0);
        while (!feof($handle)) {
            echo fgets($handle, $chunksize);
            flush();
        }
        fclose($handle);
        die;
    }else{
        return false;
    }
 }
?>