freebsd-dev/tools/test/devrandom/stat.16bit

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#!/usr/bin/perl
#
# Perform primitive binning into 16-bit bins (take 16bits of randomness
# at a time) and see if the distribution is flat. The output should be
# checked by eye - are all the numbers roughly the same?
#
# Redirect the output from this to a file - and go to the movies while
# it runs. This program is a CPU Hog!
#
1999-08-28 01:08:13 +00:00
# $FreeBSD$
#
for ($i = 0; $i < (1024*64); $i++) {
open(BIN, "/dev/urandom") || die "Cannot open /dev/urandom - $!\n";
$len = sysread(BIN, $a, 512);
close(BIN);
if ($len > 0) {
for ($j = 0; $j < $len; $j += 2) {
$k = unpack("S", substr($a, $j, 2));
$bin[$k]++;
}
}
}
for ($i = 0; $i < 1024*64; $i++) {
printf("%.2X ", $bin[$i]);
}
printf "\n";