What's the difference between WordPress defined function random_int() and PHP built-in function random_int()?

Also, if there is a difference, how does the PHP interpreter understand which of the two functions I'm calling?

What's the difference between WordPress defined function random_int() and PHP built-in function random_int()?

Also, if there is a difference, how does the PHP interpreter understand which of the two functions I'm calling?

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Share Improve this question edited Aug 29, 2018 at 11:21 Fayaz 9,01722 gold badges3333 silver badges5151 bronze badges asked Aug 28, 2018 at 12:22 Juri RudiJuri Rudi 30122 silver badges88 bronze badges

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1 Answer 1

Sorted by: Reset to default 17 +50

WordPress is old. In fact, it is older than PHP7, in which PHP introduced random_int(). WP wanted/needed this functionality before, so another method was implemented.

how does the PHP interpreter understand which of the two functions I'm calling?

Good question. The interpreter doesn't understand this. And hence, if you had PHP7 and would define this function new, you would get an error. This is why. the file with the function definition is only loaded, when random_int() is not available by default.

wp-includes/random_compat/random.php lines 212-214 are

if (!function_exists('random_int')) {
    require_once $RandomCompatDIR.'/random_int.php';
}

• So if your server is PHP7 and PHP's own random_int() is callable, this one is used and the file never included.

• If your server is not PHP7 or PHP's own random_int() is not callable for any reasons, the file is included and another implementation will be given.

This is done, so WordPress can run on different systems. Those with PHP5 and those with PHP7.

How is it different? I can't really speak to it. The files WP uses seem to be from this random_compat repository, which is also linked from the PHP doc (and suggested if you don't have PHP's own implementation available).

One quick difference that I already saw: PHP's random_int() tries to use getrandom(2) on Linux machines, while the compat random_int() only uses /dev/urandom.

When in doubt, I would use the system's versions (PHP) instead of those introduced by software (WP). But that is only my opinion.