Basically, I want formal acknowledgment that I wrote the program, so that I can mention it on my resumé. Also, if I don't copyright the code, someone else could steal my idea, say it was their idea, and sue me for infringing on their
copyright. I have no idea whether there's some other way besides a copyright that I can take formal credit for being the code's author.
I'm hoping that if I become known for writing good code, some company will hire me, and they can worry about the legal side of things for