#!/usr/bin/perl
use strict;
use warnings;

my @strings;

while (<DATA>) {
        #  Split up input stream using dashes
        my @smallarray = split '-';     #  @smallarray now has 'aaa bbb ccc', etc.

        #  Iterate through @smallarray items and split them up using spaces
        #  Create an array of anonymous array references
        #  The references are the array resulting from split, using []
        push(@strings, [split /\s/]) foreach (@smallarray);
}