Giving your code the once-over, I can imagine that GetInfDataFiles is being called with no parameter, or a parameter that is undef. May I suggest inserting

unless ($path) {die "empty or no parameter passed to GetInfDataFiles!"
+}
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As you say you're a total newbie, I'll point out that unless is one of perl's cooler control structures; it's the complement to if -- it tests for falseness, where if tests for truth. For this type of test using if, you'd need to write

if (! $path) {die "empty or no parameter passed to GetInfDataFiles!"}
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and I think the negation inside the if isn't too much clearer than the unless.
OK, so now that you know the unless will only execute when its fails, whenever your sub dies like this, you'll know that the $code was blank.