php remove filename from url if exists

Question

hello I would like to remove all filenames from my url :

http://website.com/folder1/folder2/filename.php

here is what I have tried :

$file_info = pathinfo('http://website.com/folder1/folder2/filename.php');
echo $file_info['dirname'];

outputs http://website.com/folder1/folder2/ wich is what I want , but when I try this :

   $file_info = pathinfo('http://website.com/folder1/folder2/');
    echo $file_info['dirname'];

it outputs http://website.com/folder1/.  
now what I want is if the url contains a filename then it gets removed , and if url has only folders then do nothing .
(I don't want to use .htaccess for this)

Answer 1

Assuming that all filenames have an extension:

$url1 = 'http://website.com/folder1/folder2/filename.php';
$url2 = 'http://website.com/folder1/folder2/';

echo removeFilename($url1) . "\n";
echo removeFilename($url2) . "\n";

function removeFilename($url)
{
    $file_info = pathinfo($url);
    return isset($file_info['extension'])
        ? str_replace($file_info['filename'] . "." . $file_info['extension'], "", $url)
        : $url;
}