in reply to My first attempt to design a module
You might want to take a peek at Moose as an OO framework. It already takes care of many things you'd otherwise might end up reinventing.
Other than that, I'd include the $! variable in your error messages for open and close, since that will contain the actual error message. You might also like autodie since it'll take care of this for you. It's in core since 5.10.1.
Ordinary morality is for ordinary people. -- Aleister Crowley
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