use strict;
...
sub ip_sorter {
##</code><code>##

    my @a_parts = split /\./, $a;
    my @b_parts = split /\./, $b;

    my $result;
    map { return $result if $result = ($a_parts[$_] <=> $b_parts[$_]) } (0 .. $#a_parts);

##</code><code>##

...
   map { return $^C if ($a_parts[$_] <=> $b_parts[$_]) };
...