May I suggest that you call Storable::store() in your:

# some code here
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processing on a regular basis? The problem with calling store() at random points is that the data structure you want to save may be in an inconsistent state. Storable::store is very efficient and so it is not a problem to call it frequently whenever you have made a consistent set of modifications to your data, perhaps, for example, at the end of your while loop. This would eliminate the need to catch the Ctrl-C in your code and so make your script simpler and more reliable.