- preg_replace: documentation ( source)
<?php
$originaldescription = '::cck::3::/cck::
::description::
test1
::/description::';
$description = null;
$regex_part1 = '/^::cck.*\n.*description::\n/';
$regex_part2 = '/\n.*\/description::/';
$description = preg_replace($regex_part1,null,$originaldescription);
$description = preg_replace($regex_part2,null,$description);
echo $description;