<?php
$pattern = '(foo|bar)/*';
$pattern = preg_quote($pattern, '#');
// Asterisks are translated into zero-or-more regular expression wildcards
// to make it convenient to check if the strings starts with the given
// pattern such as "library/*", making any string check convenient.
$pattern = str_replace('\*', '.*', $pattern).'\z';
echo '#^'.$pattern.'#';