(PHP 4, PHP 5, PHP 7, PHP 8)
long2ip — 将长整型转化为字符串形式带点的互联网标准格式地址（IPV4）
$proper_address
) : stringlong2ip() 函数通过长整型的表达形式转化生成带点格式的互联网地址（例如：aaa.bbb.ccc.ddd ）。
proper_address合格的地址，长整型的表达形式。
返回字符串的互联网 IP 地址。
| 版本 | 说明 |
|---|---|
| 7.1.0 |
参数 proper_address 的类型从 string 改成 integer。
|
Note:
在 32 位架构中，从 string 转换 integer 整型形式的 ip 地址将有可能导致错误的结果，因为结果数字超出了
PHP_INT_MAX限制。
an Anonymous wrote several years ago that you should cast the parameter to float to make sure that you get the right result on 32-bit machines. That probably never worked.
But the idea is on a good track: to convert a bitstring into an ip, use
$ip = long2ip((int)bindec($bits));
This works on 32- and 64-bit machines.
For a 32bit safe long2ip, which can accept string or signed integer input, try:
function safelong2ip($long) {
$binStr = sprintf("%032s", decbin((float)$long));
if (strlen($binStr) != 32) {
throw new Exception("Invalid IPv4 subnet!");
}
$ipArr = [];
for ($i = 0; $i < 4; ++$i) {
$ipArr[] = bindec(substr($binStr, $i*8, 8));
}
return implode('.', $ipArr);
}
Use these two functions to convert from and to numbers compatible to MySQLs INET_ATON and INET_NTOA
<?php
function convertIpToString($ip)
{
$long = 4294967295 - ($ip - 1);
return long2ip(-$long);
}
function convertIpToLong($ip)
{
return sprintf("%u", ip2long($ip));
}
?>
If you're running a 32 bit machine you can get wrong IPs. To prevent from this just cast to float e.g.
<?php
long2Ip32bit($ip){
return long2ip((float)$ip);
}
?>
Beware when processing values that are invalid, you may get values that are different based on the OS. For instance:
$ip = long2ip(pow(2,32)+1024);
On windows you get 255.255.255.255. On linux it's 0.0.4.0.
So it seems it would be important to make sure the long you're converting is in the correct range.
If the function doesn't exist:
<?
if (!function_exists("long2ip")) {
function long2ip($long) {
// Valid range: 0.0.0.0 -> 255.255.255.255
if ($long < 0 || $long > 4294967295) return false;
$ip = "";
for ($i=3;$i>=0;$i--) {
$ip .= (int)($long / pow(256,$i));
$long -= (int)($long / pow(256,$i))*pow(256,$i);
if ($i>0) $ip .= ".";
}
return $ip;
}
}
?>
when importing ip-ranges to a mysql database using an INT(10) field - NOTE: that you will get problems when using intval() function!
copied from "cleong" : 02-Oct-2001 02:21
intval() handles overflow differently depending on the type of the argument.
<?php
// intval('10000000000') = 2147483647
// intval(1e10) = 1410065408
?>
I wanted to be able to pass an IP address in a URL always as an unsigned int. I then converted it back as shown below:
$ip_addr = "192.168.100.25"; // example IP address that converts to neg #
$s32int = ip2long($ip_addr);
$us32str = sprintf("%u",$s32int); // convert to unsigned string
// display orig IP address, signed 32 bit version, unsigned 32 bit ver,
// finally converted back to IP addr
printf("%s ,%d, %s, %s", $ip_addr, $s32int, $us32str,
long2ip(-(4294967296-$us32str)));
// tested on Linux/Apache PHP 4.1.2