Random\Randomizer::getBytesFromString

(PHP 8 >= 8.3.0)

Random\Randomizer::getBytesFromString — Get random bytes from a source string

Опис

public Random\Randomizer::getBytesFromString(string $string, int $length): string

Generates a string containing uniformly selected random bytes from the input string with the requested length.

The chance for a byte to be selected is proportional to its share of the input string. If each byte occurs the same amount of times, each byte is equally likely to be selected.

Параметри

string: The string from which the returned bytes are selected.
length: The length of the random string that should be returned in bytes; must be 1 or greater.

Значення, що повертаються

A string containing the requested number of random bytes taken from the input string.

Помилки/виключення

If string is empty, a ValueError will be thrown.
If the value of length is less than 1, a ValueError will be thrown.
Будь-який нащадок класу Throwable, що викидається методом Random\Engine::generate() основного рушія Random\Randomizer::$engine.

Приклади

Приклад #1 Random\Randomizer::getBytesFromString() example

<?php
$randomizer = new \Random\Randomizer();

printf(
    "%s.example.com",
    $randomizer->getBytesFromString('abcdefghijklmnopqrstuvwxyz0123456789', 16)
);
?>

Поданий вище приклад виведе щось схоже на:

3zsw04eiubcf82jd.example.com

Приклад #2 Generate a random code for multi-factor authentication

<?php
// The Secure engine is the default, but we make it explicit, because
// multi-factor codes are security sensitive.
$randomizer = new \Random\Randomizer(new \Random\Engine\Secure());

echo implode('-', str_split($randomizer->getBytesFromString('0123456789', 20), 5));
?>

Поданий вище приклад виведе щось схоже на:

11551-80418-27047-42075

Приклад #3 Select from a string with a non-uniform distribution

<?php
$randomizer = new \Random\Randomizer();

echo $randomizer->getBytesFromString('aaaaabcdef', 20);
?>

Поданий вище приклад виведе щось схоже на:

fddacbeaaeaaacaaaaca

Прогляньте також

Random\Randomizer::getBytes() - Get random bytes

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