- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
$pattern = '/(\/.*)?\/img\/.*/i';
$s = [
'/img/up/bf9b12de5ea78cecacd3dde69f2a72f8/665/0c2795fc83d114a5ab9840120a4249e4/4/xxl.jpg',
'/var/www/vb/admin/web/img/up/bf9b12de5ea78cecacd3dde69f2a72f8/665/0c2795fc83d114a5ab9840120a4249e4/4/xxl.jpg',
'/var/www/vb/frontend/web/img/up/bf9b12de5ea78cecacd3dde69f2a72f8/665/0c2795fc83d114a5ab9840120a4249e4/4/xxl.jpg',
];
var_dump([
preg_match($pattern, $s[0]),
preg_match($pattern, $s[1]),
preg_match($pattern, $s[2]),
]);