Using -w and strict would *probably* give you an error message something like 'read on closed filehandle'.

You're attempting to populate @fields where you declare it, and before you open the filehandle.

@fields will be empty, which is a problem in your hash slice.

I'm not sure what you intend to do, but I will personally guarantee that -w and strict will catch this error, and that you'll have better luck if there's something in @fields.