- var_dump: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$s = '/var/www/vb/frontend/web/img/up/bf9b12de5ea78cecacd3dde69f2a72f8/140/5982aff2432c4e1847306300b0bd7622/19/s.jpg';
var_dump(preg_match_all('/^(.*)\/img\/up\/(.*)\.jpg$/i', $s));