sub get_traceroute() {
	my $hostname = $_[0];

	my $buf = '';
	if( open my $pipe, "traceroute -I -n $hostname |" ) {
		my $start = [gettimeofday];
		while(1) {
			my $vin = '';
			vec($vin, fileno($pipe), 1 ) = 1;
			if( select($vin,undef,undef,1) ) {
				sysread $pipe, $buf, 2048, length $buf
					or last;
			}
			last if tv_interval($start, [gettimeofday]) >= 2;
		}
		close $pipe;
	}
	return $buf;
}