Sorting IP addresses 

• e.g. 192.168.2.77

my @sorted = sort {
    my @a = split /[.]/, $a;
    my @b = split /[.]/, $b;
    $a[0] <=> $b[0] or
    $a[1] <=> $b[1] or
    $a[2] <=> $b[2] or
    $a[3] <=> $b[3]
} @addr;