...
while(<$fh>){

  chomp;
    (my $ip =
       $_) =~ m/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/; 
  print $ip,$/;
}
...

##</code><code>##

...
while (<$fh>) {
  chomp;
    my $ip="";
    if (m/(?<matched_ip>(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}))/){
      $ip = $+{matched_ip};
    } 
  print $ip,$/;
}
...