Random long long generator C++ [closed]

Answer 1

Under linux you can read from /dev/random or /dev/urandom

They both provide cryptographic entropy.

Difference between them being: /dev/random blocks if entropy is exhausted, therefore it could be slower than /dev/urandom but is "stronger"

So, using streams it will look like this

long long n;
std::ifstream rstream ("/dev/random");
rstream >> n;