可重现的随机数系列 [英] reproducible random number series

问题描述

如何在PHP中获得一系列可重现的伪随机数?

在旧版本的PHP中，我可以使用 RNG ，但由于PHP更改了rand和mt_rand的工作方式而不再起作用.

也请在PHP.net页面上查看此注释:

请记住，Suhosin修补程序默认情况下安装在 许多PHP安装(例如Debian和DirectAdmin)完全禁用 出于加密安全原因，使用srand和mt_srand函数.到 从一个 Suhosin加固的服务器，您将需要包括自己的伪随机 生成器代码.

该评论的

链接: http://www.php.net/manual/zh-CN/function.srand.php#102636

有没有解决方案?我没有时间也没有经验来创建自己的伪随机生成器代码.

我的目标是拥有一个代码

<?php
   //( pseudo random code here...)
   $the_seed = 123; // 123 is just a number for demo purposes, NOT a static number
                    //...i hope you get the idea. It's just a hardcoded seed,
                    // it could be a seed based on a user-id, a date etc...
                    // we need the same output for a given seed.
   //( pseudo random code here...)

   // ...and finally
   echo $the_random_number;
 ?>

因此，每次我访问此页面时，我应该获得相同的号码.

解决方案

Mersenne Twist是一种不错的快速PRNG，这是它的一个公共领域PHP实现:

http://kingfisher.nfshost.com/sw/twister/

仅在PHP 5.3.0及更高版本上有效.

How can i get a series of reproducible pseudorandom numbers in PHP?

In older versions of PHP i could do that just by using the same seed in the RNG, but it does not work anymore since PHP has changed the way rand and mt_rand works.

Please also see this comment in PHP.net page:

Keep in mind that the Suhosin patch which is installed by default on many PHP-installs such as Debian and DirectAdmin completely disables the srand and mt_srand functions for encryption security reasons. To generate reproducible random numbers from a fixed seed on a Suhosin-hardened server you will need to include your own pseudorandom generator code.

link of that comment: http://www.php.net/manual/en/function.srand.php#102636

Is there any solution ready? I do not have the time nor the experience to create my own pseudo-random generator code.

My goal is to have a code

<?php
   //( pseudo random code here...)
   $the_seed = 123; // 123 is just a number for demo purposes, NOT a static number
                    //...i hope you get the idea. It's just a hardcoded seed,
                    // it could be a seed based on a user-id, a date etc...
                    // we need the same output for a given seed.
   //( pseudo random code here...)

   // ...and finally
   echo $the_random_number;
 ?>

so everytime i visit this page i should get the same number.

解决方案

The Mersenne Twist is a nice fast PRNG and here's a public domain PHP implementation for it:

http://kingfisher.nfshost.com/sw/twister/

That only works on PHP 5.3.0 and above.

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