How random is PHP's shuffle function?

Question

Does anyone know what\'s the randomness of PHP\'s shuffle() function? Does it depend on the operating system? Does it use PHP\'s own seeder?

Is it poss

Answer 1

Update for PHP 7.1

Since the rng_fixes rfc was implemented for PHP 7.1, the implementation of shuffle now utilizes the Mersenne Twister PRNG (i.e. it uses mt_rand and is affected by calling mt_srand).

The legacy system PRNG (rand) is no longer available; the functions rand and srand are in fact aliased to their mt_ equivalents.