my $file = 'dfedc.out';
my $ziel = "inactive_ports.txt";

my @inactive_ports;

{
    local $/ = "\n\n";
    open my $fh, '<', $file or die $!;
    while ( my $port_data = <$fh> ) {
        if ( $port_data =~ /Policy name\s*:\s*no policy applied/ ) {
            my ($port) = $port_data =~ /Port\s*:\s*([\w.]+)/;
            push @inactive_ports, $port;
        }
    }
    close $fh;
}

print "Inactive Ports: @inactive_ports\n";

#Zieldatei öffnen und schreiben
open(OUT,">$ziel");
print OUT @inactive_ports;
close(OUT);