- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
$pattern = "#/(?<moduleName>[^/]+)/layout/[^/]*\.xml$#i";
$filename = "/var/www/project/vendor/magento/theme-frontend-blank/Magento_Theme/layout/default_head_blocks.xml";
var_dump(preg_match($pattern, $filename, $matches), $matches);
$pattern = "#/([^/]+)/layout/[^/]*\.xml$#i";
var_dump(preg_match($pattern, $filename, $matches), $matches);