(PHP 4 >= 4.0.4, PHP 5)
gmp_random — Random number
Generate a random number. The number will be between zero and the number of bits per limb multiplied by limiter . If limiter is negative, negative numbers are generated.
A limb is an internal GMP mechanism. The number of bits in a limb is not static, and can vary from system to system. Generally, the number of bits in a limb is either 16 or 32, but this is not guaranteed.
The limiter. Defaults to 20.
It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.
A random GMP number.
Example #1 gmp_random() example
<?php
$rand1 = gmp_random(1); // random number from 0 to 1 * bits per limb
$rand2 = gmp_random(2); // random number from 0 to 2 * bits per limb
echo gmp_strval($rand1) . "\n";
echo gmp_strval($rand2) . "\n";
?>
上例将输出：
1915834968 8642564075890328087