- print_r: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$pat = ',(?P<controller>[[:alnum:]]+)/(?P<action>[[:alnum:]]+)/(?P<vvv>[[:alnum:]]+),';
$str = 'controller1/action1/fff';
preg_match_all($pat, $str, $matches);
print_r($matches);