use Modern::Perl;
use File::Slurp qw/read_file/;
use Regexp::Common qw/net/;

sub R_loop2 {
    my ( $file, $loop, %seen ) = 'junk.txt';

    for my $fileName ( read_file $file ) {
        chomp $fileName;

        say 'The packet traversed this path:';
        for my $fileLine ( read_file $fileName ) {
            $fileLine =~ /($RE{net}{IPv4})/ or next;
            $loop++ if ++$seen{$1} > 1;
            say $1;
        }
    }

    if ($loop) {
        say 'Routing Loop Detected';
        return 1;
    }
}