How can I detect the operating system in Perl?

Question

I have Perl on Mac, Windows and Ubuntu. How can I tell from within the script which one is which? Thanks in advance.

Edit: I was asked what I am doi

Answer 1

The variable $^O (that's a capital 'O', not a zero) holds the name of the operating system.

Depending on what you want, it may or may not give the answer you want - on my system it gives 'linux' without saying which distro. I'm not so sure about what it says on Windows or MacOS.