List null routed IPs

<?php

$blackhole = array();

$i = 0;

exec('ip route list', $exec);
foreach ($exec as $k => $v) {
$pos = strpos($v, 'blackhole');

// Note our use of ===.  Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.
if ($pos === false) {

} else {

$var = explode("blackhole ", $v);
$blackhole[$var[1]] = $var[1];
$i++;
}
}

echo $i." IP's blocked
";
?>