[RESOLVED] HELP needed with file upload

[RossBryan]

Can anybody help with this little problem i have. Im pretty new to PHP im trying to develop a file upload site, and have bumped into a problem when trying to apply, I think the end() function; not quite sure for certain. The script isnt complete but in essence at this stage im trying to varify if the file extension the user has choosen is one of the allowed extensions.

Heres the script followed by the error message displayed:

<?php require ("design/top.php"); 

if (!(isset($_SESSION['user'])&& $_SESSION['user']!=''))
{
    header("Location: loginC2S.php");    
}

?>
    
<title>boxeD:IN - Upload</title>
<div id= 'left'> <br />
    
        
<?php
        
if (isset ($_FILES['userfile']))
{
    $errors = array(); //list of errors
    $allowed_ext = array('jpg','jpeg','gif','png','mp3');
            
    $file_name = $_FILES['userfile']['name']; 
    $file_ext = strtolower (end(explode ('.', $file_name)));        
    $file_size = $_FILES ['userfile']['size'];    
    $file_tmp = $_FILES ['userfile']['tmp_name'];    
            
    if (in_array($file_ext, $allowed_ext) ===false)    
    {
        $errors[] = "Extension not allowed!!!";
    }

}
        
        
?>
        
<form action ='upload.php' method ='POST' enctype ='multipart/form-data'> 
    <table>
        <tr>
            <td>Select file to upload:</td>
        </tr>
        <tr>
            <td><input type='file' name='userfile'/></td>
        </tr>
        <tr>
            <td><input type='submit' value='Upload'/></td>
        </tr>
    </table>        
</form>

</div>
    
<?php require ("design/bottom.php"); ?>

Error Message:

Strict Standards: Only variables should be passed by reference in C:\xampp\htdocs\Care2Share\upload.php on line 22

The error message is refering to:

$file_ext = strtolower (end(explode ('.', $file_name))); 

Any help would be much appreciated. Thanks

[badben]

I personally would get the file extension using php's native function like this:

$file_info = pathinfo($file_name);
$file_ext = $file_info['extension'];

[RossBryan]

Thanks ended up resolving the problem using pathinfo as advised:

$file_ext = pathinfo($file_name, PATHINFO_EXTENSION); 

The following also worked great:

$array = explode ('.', $file_name); 
$file_ext = strtolower (end($array));