php根据子网掩码和ip计算子网

$ip = ‘192.168.6.1‘;
$mask = ‘255.255.2.0‘;
$sub_net = array();//子网
$ip_explode = explode(‘.‘, $ip);
$mask_explode = explode(‘.‘, $mask);
foreach ($ip_explode as $key => $ip_num) {
    //10进制转2进制
    $a = decbin($ip_num);
    $b = decbin($mask_explode[$key]);
    //补0补够8位
    $a = sprintf("%08d", $a);
    $b = sprintf("%04d", $b);//前补0
    $b = sprintf("%0.4f", $b);//后取多少位
    echo $a."==".$b."\n";

    $c = $a & $b;
    echo $c."\n";
    $d = bindec($c);
    echo $d."\n";
    $sub_net[] = $d;
}
$sub_net = implode(‘.‘, $sub_net);
echo $sub_net;