How do I get the full path to a Perl script that is executing?

Question

I have Perl script and need to determine the full path and filename of the script during execution. I discovered that depending on how you call the script $0 va

Answer 1

$0 is typically the name of your program, so how about this?

use Cwd 'abs_path';
print abs_path($0);

Seems to me that this should work as abs_path knows if you are using a relative or absolute path.

Update For anyone reading this years later, you should read Drew's answer. It's much better than mine.