How to Automatically Start a Download in PHP?
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09-06-2019 - |
Question
What code do you need to add in PHP to automatically have the browser download a file to the local machine when a link is visited?
I am specifically thinking of functionality similar to that of download sites that prompt the user to save a file to disk once you click on the name of the software?
Solution
Send the following headers before outputting the file:
header("Content-Disposition: attachment; filename=\"" . basename($File) . "\"");
header("Content-Type: application/octet-stream");
header("Content-Length: " . filesize($File));
header("Connection: close");
@grom: Interesting about the 'application/octet-stream' MIME type. I wasn't aware of that, have always just used 'application/force-download' :)
OTHER TIPS
Here is an example of sending back a pdf.
header('Content-type: application/pdf');
header('Content-Disposition: attachment; filename="' . basename($filename) . '"');
header('Content-Transfer-Encoding: binary');
readfile($filename);
@Swish I didn't find application/force-download content type to do anything different (tested in IE and Firefox). Is there a reason for not sending back the actual MIME type?
Also in the PHP manual Hayley Watson posted:
If you wish to force a file to be downloaded and saved, instead of being rendered, remember that there is no such MIME type as "application/force-download". The correct type to use in this situation is "application/octet-stream", and using anything else is merely relying on the fact that clients are supposed to ignore unrecognised MIME types and use "application/octet-stream" instead (reference: Sections 4.1.4 and 4.5.1 of RFC 2046).
Also according IANA there is no registered application/force-download type.
A clean example.
<?php
header('Content-Type: application/download');
header('Content-Disposition: attachment; filename="example.txt"');
header("Content-Length: " . filesize("example.txt"));
$fp = fopen("example.txt", "r");
fpassthru($fp);
fclose($fp);
?>
my code works for txt,doc,docx,pdf,ppt,pptx,jpg,png,zip extensions and I think its better to use the actual MIME types explicitly.
$file_name = "a.txt";
// extracting the extension:
$ext = substr($file_name, strpos($file_name,'.')+1);
header('Content-disposition: attachment; filename='.$file_name);
if(strtolower($ext) == "txt")
{
header('Content-type: text/plain'); // works for txt only
}
else
{
header('Content-type: application/'.$ext); // works for all extensions except txt
}
readfile($decrypted_file_path);