#!/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);
}

##</code><code>##

#       The array of anonymous arrays now looks like this:
#
#       $VAR1 = [
#                       'aaa',
#                       'bbb',
#                       'ccc'
#               ];
#       $VAR2 = [
#                       'ddd',
#                       'eee',
#                       'fff'
#               ];
#       $VAR3 = [
#                       'ggg',
#                       'hhh',
#                       'iii'
#               ];
#       $VAR4 = [
#                       'jjj',
#                       'kkk',
#                       'lll'
#               ];

##</code><code>##

#  Print out the whole AoA contents
foreach my $arrayref (@strings) {
        print "$_\n" foreach @$arrayref;
}

print "----\n\n";

#  Or just the contents of one group
foreach my $item (@{$strings[0]}) {
        print "$item\n";
}

__DATA__
aaa bbb ccc-ddd eee fff-ggg hhh iii-jjj kkk lll-

__OUTPUT__
aaa
bbb
ccc
ddd
eee
fff
ggg
hhh
iii
jjj
kkk
lll
----

aaa
bbb
ccc