The C programming language is the concrete foundation of the UNIX operating system, but although it's powerful, it's also rigid and useless for simple tasks. Perl is a great alternative and the de facto language of the World Wide Web, and it has a fabulous developer community. I'd recommend that if you want to become a UNIX genius, learn C first, but if you want to be a power user and have the ability to create top-notch CGI (Web) solutions, Perl is the way to go.
Kudos to inventor Larry Wall and his large team of codevelopers.