Merge several lists of the networks

merge.pl

use strict;
use Net::IP;

my @ips = ();
my $result = shift @ARGV;

for(my $i = 0; $i < @ARGV; ++$i) {
    open(my $in, $ARGV[$i]) or warn "Can't open $ARGV[$i]: $!";
    while (!eof($in)) {
    	defined(my $line = readline $in) or die "readline failed for $ARGV[$i]: $!";	
	my $ip = new Net::IP ($line) or die (Net::IP::Error());
	push @ips, $ip;
    }
}

@ips = sort { $a->binip() cmp $b->binip(); } @ips;

open(my $out, ">", $result) or warn "Can't open $result: $!";

for(my $i = 0; $i < @ips; ++$i) {
	my $a = $ips[$i];
	unless(defined($a)) {
		next;
	}
	for(my $j = $i + 1; $j < @ips; ++$j) {
		my $b = $ips[$j];
		unless(defined($b)) {
			next;
		}
		if($a->last_bin() < $b->binip()) {
			last;
		}
		if($a->overlaps($b) != $IP_NO_OVERLAP) {
			undef $ips[$j];	
		}
	}
	
	print $out $a->ip(), "/", $a->prefixlen(), "\n";
}