seriyPS

No, there is no shell. Only main() function can be evaluated. You may be interested in http://tryerlang.org/, but it is much more restricted.

I don't understand about which window you are talking about. May you make a screenshot?

Don't worry - it's on read-only chroot and inside restricted linux sandbox. You may try to read /etc/passwd http://tryerl.seriyps.ru/#id=30f6 or even list running OS processes http://tryerl.seriyps.ru/#id=12f2