- ob_get_clean: documentation ( source)
- var_dump: documentation ( source)
- ob_start: documentation ( source)
- preg_match_all: documentation ( source)
- phpinfo: documentation ( source)
- array_unique: documentation ( source)
<?php
if (PHP_VERSION >= "5.5") {
ob_start();
phpinfo();
$phpinfo = ob_get_clean();
preg_match_all('/5\.5\.[\d\w.]+/i', $phpinfo, $matches);
var_dump(array_unique($matches[0]));
}