freebsd-dev/tools/test/devrandom/hammer.urandom

#!/usr/bin/perl

#
# Test program for /dev/urandom
# Read and display random numbers.
# This also reads /dev/zero to make sure there is no brokenness there.
#
# $FreeBSD$
#

open(ZERO, "/dev/zero") || die "Cannot open /dev/zero - $!\n";

for (;;) {
	open(BIN, "/dev/urandom");
	$len = sysread(BIN, $a, 20);
	sysread(ZERO, $b, 20);
	close(BIN);
	if ($len > 0) {
		for ($j = 0; $j < $len; $j += 2) {
			$k = unpack("S", substr($a, $j, 2));
			$z = unpack("S", substr($b, $j, 2));
			$z == 0 || die "/dev/zero is returning non-zero!\n";
			printf("%.4X ", $k);
		}
		printf "\n";
	}
}