You're hinting that it's not in POSIX, and this is true. There are many standards and cross-platform interfaces defined outside of POSIX. Some explicit and top

You're hinting that it's not in POSIX, and this is true. There are many standards and cross-platform interfaces defined outside of POSIX. Some explicit and top-down, some organically evolved. The spec for /dev/*random is here, as was published in the mid-90s: http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/drivers/char/random.c?id=HEAD#n98 http://git.kernel.org/cgit/linux/kernel/git/stable/linux-sta...