請參考如下作法：

function getDirFilePathAry($directory, &$filePathAry)
{
	$mydir = dir($directory);
	while($file = $mydir->read())
	{
		if($file != "." && $file != ".." &&
			strpos($file, '.php') !== false)
		{
			if((is_dir("$directory/$file")))
			{
				getDirFilePathAry("$directory/$file", $filePathAry);
			}else{
				$filePathAry[] = $directory/$file;
			}
		}
	}
	$mydir->close();
}

function findUrlFileAry($filePathAry, $url)
{
    $fileAry = array();
	foreach($filePathAry as $file)
	{
		$fileStrAry = file($file, FILE_IGNORE_NEW_LINES);
		foreach($fileStrAry as $str)
		{
			if(strpos($str, $url) !== false))
			{
				$fileAry[] = $file;
				break;
			}
		}
	}
	return $fileAry;
}


$filePathAry = array();
$directory = $_SERVER['DOCUMENT_ROOT']."/";
// 取得所有檔案
getDirFilePathAry($directory, $filePathAry);
$url = 'www.test.com';
// 取得有url的所有檔案
$fileAry = findUrlFileAry($filePathAry, $url);

echo '<pre>';
    var_dump($fileAry);
echo '</pre>';