如前所述，所有IPv4地址都可以使用 ip2long（）转换为数字，然后使用 long2ip（）转换回数字。我不确定您是否已经注意到，最关键的一点是顺序IP与顺序号相对应，因此您可以操纵这些数字！

As you've already noted, all IPv4 addresses can be converted to numbers using ip2long(), and converted back using long2ip(). The critical extra bit I'm not sure you've noticed is that sequential IPs correspond with sequential numbers, so you can manipulate these numbers!

给出CIDR前缀（例如， $ prefix = 30 ），则可以使用位移运算符：

Given a CIDR prefix (e.g, $prefix = 30 for your range), you can calculate the number of IPs in that range using a bit shift operator:

$ip_count = 1 << (32 - $prefix);

然后使用以下方法遍历该范围内的所有IP：

And then loop through all the IPs in that range using:

$start = ip2long($start_ip);
for ($i = 0; $i < $ip_count; $i++) {
    $ip = long2ip($start + $i);
    // do stuff with $ip...
}