By the way, perldoc is perl's online help and is installed with perl. It's a fantastic reference and easy to use.
At a command prompt type:
perldoc -f stat or any function name for info about the function and what args it expects and what it returns, perldoc perlop to decipher all of those funky operators, perldoc perlsyn perldoc perlref perldoc perlfaq
are all worth looking at as well.