Unsigned int可以登录php [英] Unsigned int to signed in php

问题描述

看来，在32位操作系统中，ip2long返回带符号的int，而在64位操作系统中，则返回了unsigned int.

It appears, that in 32bit OS ip2long returns signed int, and in 64bit OS unsigned int is returned.

我的应用程序在10台服务器上工作，有些是32位的，有些是64位的，所以我需要它们全部以相同的方式工作.

My application is working on 10 servers, and some are 32bit and some are 64bit, so I need all them to work same way.

在PHP文档中，有一个技巧可以使结果始终为未签名，但是由于我的数据库已经充满了数据，因此我希望对其进行签名.

In PHP documentation there is a trick to make that result always unsigned, but since I got my database already full of data, I want to have it signed.

那么如何在PHP中将未签名的int更改为已签名的int?

So how to change an unsigned int into a signed one in PHP?

推荐答案

PHP不支持将无符号整数作为类型，但是您可以做的只是将 sprintf将/ip2long"rel =" noreferrer> ip2long 转换为无符号整数 string 用%u将该值解释为无符号的:

PHP does not support unsigned integers as a type, but what you can do is simply turn the result of ip2long into an unsigned int string by having sprintf interpret the value as unsigned with %u:

 $ip="128.1.2.3";
 $signed=ip2long($ip);             // -2147417597 in this example
 $unsigned=sprintf("%u", $signed); //  2147549699 in this example

编辑，因为您确实希望甚至在64位系统上也对其进行签名-这是将64位+ ve值转换为等效的32位签名的方法:

Edit, since you really wanted it to be signed even on 64 bit systems - here's how you'd convert the 64 bit +ve value to a 32 bit signed equivalent:

$ip = ip2long($ip);
if (PHP_INT_SIZE == 8)
{
    if ($ip>0x7FFFFFFF)
    {
        $ip-=0x100000000;
    }
}

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