(PHP 8 >= 8.3.0)
Random\Randomizer::getBytesFromString — Get random bytes from a source string
public Random\Randomizer::getBytesFromString(string $string, int $length): string
Generates a string containing uniformly selected random bytes from the input string with the requested length.
The chance for a byte to be selected is proportional to its share of the input string. If each byte occurs the same amount of times, each byte is equally likely to be selected.
A string containing the requested number of random bytes taken from the input string.
string is empty, a ValueError will be thrown. length is less than 1, a ValueError will be thrown. Random\Randomizer::$engine. Example #1 Random\Randomizer::getBytesFromString() example
<?php
$randomizer = new \Random\Randomizer();
printf(
"%s.example.com",
$randomizer->getBytesFromString('abcdefghijklmnopqrstuvwxyz0123456789', 16)
);
?> The above example will output something similar to:
3zsw04eiubcf82jd.example.com
Example #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));
?> The above example will output something similar to:
11551-80418-27047-42075
Example #3 Select from a string with a non-uniform distribution
<?php
$randomizer = new \Random\Randomizer();
echo $randomizer->getBytesFromString('aaaaabcdef', 20);
?> The above example will output something similar to:
fddacbeaaeaaacaaaaca
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https://www.php.net/manual/en/random-randomizer.getbytesfromstring.php