Temp files

[laPistola]

Hello

 

PHP 5.3

 

Im looking for a solution to a problem. A site im building stores documents. You can then upload a newer version of that document that overrides the old document. But if you viewed the first document when trying to view the new document it loads the old one up unless you clear your internet files inbetween.

 

Is there a way to make the site not download the file to the clients computer or a way to delete the clients local temp version before downloading and opening the new document?

[premiso]

Using the header function, you can tell the browser not to cache it, for some information on that: http://lab.artlung.com/anti-cache/

 

The code to do it in PHP:

 

<?php
Header('Cache-Control: no-cache');
Header('Pragma: no-cache');
?>

 

Not sure why the above site posted that with short_open tags assumed to be on, I would use the version I just pasted here over that as an fyi.

[laPistola]

Now I have done just this but its not working, but i bet that is my code which is at fault as I didn't think my method would work as it basically loaded a new page without the header info.

 

My first way was:

<?php
// stop cashing
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
?>
<a href="file.doc" target="_blank">Click here</a>

 

and my second was in it basic form

<?php
// stop cashing
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
header("Location: file.doc");
?>

[premiso]

The issue is going to lie within the file.doc. Instead of doing a location redirect, why not just use headers and readfile to deliver the file from the php page? That way the headers work, the file is delivered without being cached and it is a win / win.

 

The other option, if you are using apache with mod_header is to set the .doc extension to not be cached, which would also prevent it from being cached.

[laPistola]

Thank you, Thank you and Thank you 

 

The mod_header wouldn't be ideal as the file could be one of about 30 different formats. Ill use the readfile() method, looking at the php manual its the perfect solution.

 

Did I thank you 

 

[laPistola]

it works perfect now.

 

If it helps anyone this is my code

$file = urldecode($_GET['file']);
if(file_exists($file)) {
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header("Cache-Control: no-cache");
header("Pragma: no-cache");
ob_clean();
flush();
readfile($file);
header("Location: ".urldecode($_GET['return']));
} else {
header("Location: ".urldecode($_GET['return'])."&status=fileErr");
}