You get a gold star for soliciting a code reveiw. Getting people to look over one's code is a real help to learning a new language.

You don't have any subs in this script? Okay, it's only 35 lines or so of actual code, but it could still be broken up into more logical chunks. I'd write subs for tempfile creation, appending a file to the tempfile, and printing a file backwards.

I see no "strict" or "warnings" here. You'll want those.