pathinfo() provides various information like dirname, basename, extension, and full filename. You can get intended result by pathinfo( $filename)['dirname']
Followings are the example to get file path:
<?php
$path_parts = pathinfo('/www/htdocs/inc/lib.inc.php');
echo $path_parts['dirname'], "\n";
echo $path_parts['basename'], "\n";
echo $path_parts['extension'], "\n";
echo $path_parts['filename'], "\n"; // since PHP 5.2.0
?>
Below is the result as an example for above:
/www/htdocs/inc lib.inc.php php lib.inc