- preg_replace: documentation ( source)
<?php
$subject = 'Fooo
<!--NOCACHE_START DEV_PROFILING-->
<div class="box box-bdr pam mtm" id="dev_ProfilingButton">
<div class="h3">Profiling (<?php echo(round((microtime(true) - ALI
<!--NOCACHE_END-->
bar';
$pattern = '/<!--NOCACHE_START\s([A-Za-z_])+-->.*<!--NOCACHE_END-->/sm';
$replace = '$1';
echo preg_replace($pattern, $replace, $subject);