Алексей

$text = 'Пользователь {user_240} сделал {action_32}!';

preg_match('/{user_(?P<user>\d+)}.*{action_(?P<action>\d+)}/', $text, $matches);

echo 'User is: ', $matches['user'], ', action: ', $matches['action'];

$urls = array('xxx.xx/yyy/page/2/?zzz=zzz', 'xxx.xx/yyy/yyy/yyy/page/21');
 
foreach ($urls as $url) {
 
    $parts = parse_url($url);
    var_dump($parts);
    $parts['path2'] = preg_replace('~/page/\d+/?$~', '', $parts['path']);
    var_dump($parts);
}

ini_set('display_errors', true);
ini_set('display_startup_errors', true);
ini_set('error_reporting', -1);