@barrkel made a small mistake, confusing rand() and random(). rand() is the earliest C random number generator. Its low-order bits (back in the day) went thro

@barrkel made a small mistake, confusing rand() and random(). rand() is the earliest C random number generator. Its low-order bits (back in the day) went through a predictable sequence, so rand() & 0x1 was a bad source of random bits. I don't think that rand() was specified so fully as to make this behavior required, but typical implementations exhibited it, so you could not use rand() for any serious work. random() came after, does not use a LCG, and thus fixed this problem, so you would not see it if your code calls random(), whose man page says: The difference [between random() and rand()] is that rand() produces a much less random sequence -- in fact, the low dozen bits generated by rand go through a cyclic pattern. All of the bits generated by random() are usable. For example, `random()&01' will produce a random binary value. Typically, because of this screwup, people use a third-party generator, like the "Mersenne twister".