/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/

##</code><code>##

my $ip;
if ($line =~ /(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/ &&
    $1 <= 255 && $2 <= 255 && $3 <= 255 && $4 <= 255) {
   $ip = "$1.$2.$3.$4";
}

##</code><code>##

my ($ip, $subnet);
if ($line =~ /(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/ &&
    $1 <= 255 && $2 <= 255 && $3 <= 255 && $4 <= 255) {
   $ip = "$1.$2.$3.$4";
   $subnet = 1 if $1 == 255;
}