- var_dump: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$text = 'My Name ## is #P_NAM3# and \r\n I am #P_AG2# years old';
//$r = '#([^#]+)#';
//$r = '#[(?<name>\S+)\]#';
$r = '#(.*?)#';
//$r = '#\w*#';
preg_match_all('/'.$r.'/m', $text, $m);
var_dump($m);