sub populate_hash {
    my %hash;
    # populate hash
    \%hash;
}

##</code><code>##

my %top_level = % { populate_hash() };

##</code><code>##

perl -e 'print "How sweet does a rose smell? "; chomp ($n = <STDIN>); $rose = "smells sweet to degree $n"; *other_name = *rose; print "$other_name\n"'