substr?

>
The code I'm having issues with is this:
>
$filename = $_FILES['userfile']['name']; // Get the name of the file
(including file extension).
$ext = substr($filename, strpos($filename,'.'),
strlen($filename)-1); // Get the extension from the filename.
>
All I want to do is grab the file extension and verify that it is a .zip or
a .pdf etc. file. This is working for small files (under a few megs) but for
some reason it fails when I get bigger. I have increased the allowed memory
size to 50 MB's I'm testing with a 44 MB file right now.


I'm not an expert on pulling in and reading files, but if all you want is
the last three characters of a file name, couldn't you just do something
like:

$extension = substr($filename, -3);

if ($extension = "pdf" || $extension = "zip") {
echo "The file is a PDF or ZIP.";
} else {
echo "Incorrect file type.";
}

??

maybe you are saying you want it to perform this check while the user is
attempting to upload the file and not after it has been uploaded?