First, don't manually copy code from perlmonks, use the download link below the code. That prevents typos.

Second, don't assume any code posted at perlmonks will solve your problem. Some people post untested or intentionally bad code, some of them to make you learn, some just don't know better, and some are simply assholes. tybalt89 has a long history of posting completely undocumented, completely unexplained code, often needlessly complex or obfuscated, often working only accidently.

Third, perlmonks is not a code writing service. We are here to help you learn perl, not to write code for you. (And this is part of the motivation for people posting bad code.)

Alexander