- preg_last_error: documentation ( source)
- get_defined_constants: documentation ( source)
- array_flip: documentation ( source)
- preg_replace: documentation ( source)
<?php
$basename = "a\xFFnything";
print("Before: ".$basename.PHP_EOL);
$basename = preg_replace('/[\x00-\x1F]/u', '_', $basename);
print("After: ".array_flip(get_defined_constants(true)['pcre'])[preg_last_error()]);