Search files recursively for a given extension in PHP

rec_search_file.php

<?php 
function search_recursively_for_extension($directory, &$array, $extension=".dat") {
	//global $debug;
	if (substr($directory, -1) === "/" || substr($directory, -1) === "\\") {
		$directory = substr($directory, strlen($directory)-1);
	}
	$nodes = scandir($directory);
	//$debug .= ("Reading Directory: ".$directory."\n").(($nodes === false || $nodes === NULL)?("false, ".(file_exists($directory)?"it does exist":"it doesn't even exist")."\n"):(var_export($nodes, true)."\n"));
	if (is_array($nodes)) {
		foreach ($nodes as $node) {
			if ($node === "." || $node === "..") continue;
			$node = $directory.DIRECTORY_SEPARATOR.$node;
			if (is_dir($node)) {
				search_recursively_for_extension($node, $array, $extension);
			} else if (substr($node, -strlen($extension)) === $extension) {
				$array[] = $node;
			}
		}
	}
}
/*
* // Usage:
* $arr = [];
* search_recursively_for_extension(__DIR__, $arr, ".php");
* foreach ($arr as $fileName)
*   echo $fileName."<br>\n";
*/