Solution to the problem of ip2long negative numbers in php

This article brings you the solution to the problem of negative ip2long numbers in PHP. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Everyone may know that PHP provides ip2long and long2ip methods to process IP addresses. Let’s talk about some concepts:

1.ip2long — Convert an IPV4 string Internet protocol into a digital format

int ip2long ( string $ip_address )
参数: ip_address 一个标准格式的地址。
返回值: 返回IP地址转换后的数字 或 FALSE 如果 ip_address 是无效的

2.long2ip — Convert a digital format into an IPV4 character String Internet Protocol

string long2ip ( string $ip_address )
参数:ip_address 长整型的正确地址表示。
返回值: 返回互联网地址作为字符串。

Example:

$ip = '10.0.0.1';
$ip_long = ip2long($ip);
echo $ip_long.PHP_EOL;  // 167772161
echo long2ip($ip_long); // 10.0.0.1

When the ip address is relatively large, ip2long will appear negative:

$ip = '192.168.100.1';
$ip_long = ip2long($ip);
echo $ip_long.PHP_EOL;  // -1062706175
echo long2ip($ip_long); // 192.168.100.1

Reason:

IPv4 uses unsigned 32-bit address, so there are at most 2 to the 32nd power minus 1 (4294967295) addresses. Write decimal numbers separated by 4 decimal points.
Remember as A.B.C.D, for example: 192.168.100.100.

Each decimal number in the IPv4 address is an unsigned byte, ranging from 0 to 255. Convert the IPv4 address to an unsigned number.

No more nonsense, solved Method:
Use %u to format it as an unsigned integer when outputting.

$ip = '192.168.100.1';
$ip_long = sprintf('%u',ip2long($ip));
echo $ip_long.PHP_EOL;  // 3232261121
echo long2ip($ip_long); // 192.168.100.1

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