List Certain Types of Files in a Directory

gistfile1.php

<?php
$folder = opendir('.'); // Use '.' only if the PHP file is in the same folder as your files, otherwise use a relative or absolute path.
$file_types = array('jpg', 'jpeg', 'gif', 'png');
$file_list = array();
while ($file = readdir ($folder)) {
    $parts = explode('.', $file);
    $ext = array_pop($parts);
    if(in_array($ext, $file_types)) {
        array_push($file_list, $file);
    }
}
closedir($folder);

print_r($file_list);
?>