random_int

(PHP 7)

random_int — Generates cryptographically secure pseudo-random integers

Описание

int random_int ( int $min , int $max )

Generates cryptographic random integers that are suitable for use where unbiased results are critical, such as when shuffling a deck of cards for a poker game.

The sources of randomness used for this function are as follows:

• On Windows, » CryptGenRandom() will always be used.
• On Linux, the » getrandom(2) syscall will be used if available.
• On other platforms, /dev/urandom will be used.
• If none of the aforementioned sources are available, then an Exception will be thrown.

Замечание: Although this function was added to PHP in PHP 7.0, a » userland implementation is available for PHP 5.2 to 5.6, inclusive.

Список параметров

min

- The lowest value to be returned, which must be PHP_INT_MIN or higher.

max

- The highest value to be returned, which must be less than or equal to PHP_INT_MAX.

Возвращаемые значения

Returns a cryptographically secure random integer in the range min to max, inclusive.

Ошибки

• If an appropriate source of randomness cannot be found, an Exception will be thrown.
• If invalid parameters are given, a TypeError will be thrown.
• If max is less than min, an Error will be thrown.

Примеры

Пример #1 random_int() example

var_dump(random_int(100, 999));
var_dump(random_int(-1000, 0));

Результатом выполнения данного примера будет что-то подобное:

int(248)
int(-898)

Смотрите также

• random_bytes() - Generates cryptographically secure pseudo-random bytes

This function is based on Andrew Moore's UUID generation function on the uniqid function; it has been updated to use random_int() on PHP 7.0 or later yet continue to function with earlier versions using mt_rand().
function generateUUIDv4()
{
    if(version_compare(PHP_VERSION,'7.0.0', '<') )
    {
        return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
        
        // 32 bits for "time_low"
        mt_rand(0, 0xffff), mt_rand(0, 0xffff),
        
        // 16 bits for "time_mid"
        mt_rand(0, 0xffff),
        
        // 16 bits for "time_hi_and_version",
        // four most significant bits holds version number 4
        mt_rand(0, 0x0fff) | 0x4000,
        
        // 16 bits, 8 bits for "clk_seq_hi_res",
        // 8 bits for "clk_seq_low",
        // two most significant bits holds zero and one for variant DCE1.1
        mt_rand(0, 0x3fff) | 0x8000,
        
        // 48 bits for "node"
        mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
        );
    }
    else
    {
        return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
        
        // 32 bits for "time_low"
        random_int(0, 0xffff), random_int(0, 0xffff),
        
        // 16 bits for "time_mid"
        random_int(0, 0xffff),
        
        // 16 bits for "time_hi_and_version",
        // four most significant bits holds version number 4
        random_int(0, 0x0fff) | 0x4000,
        
        // 16 bits, 8 bits for "clk_seq_hi_res",
        // 8 bits for "clk_seq_low",
        // two most significant bits holds zero and one for variant DCE1.1
        random_int(0, 0x3fff) | 0x8000,
        
        // 48 bits for "node"
        random_int(0, 0xffff), random_int(0, 0xffff), random_int(0, 0xffff)
        );
    }
}

Описание на ru2.php.net
Описание на php.ru