#!/usr/bin/perl -w

use strict;
use POSIX;

open R, '/dev/urandom' or die $!;

system 'cat >/dev/null &';

sub randbytes ($) {
    my ($count) = @_;
    my $s;
    my $r = read R, $s, $count;
    die $! unless $r==$count;
    return $s;
}

sub randbyteval () {
    my $b = randbytes 1;
    my ($r) = unpack 'C', $b;
    return $r;
}

sub randvalue ($$) {
    my ($min,$maxplus1) = @_;
    my $b = randbyteval;
    return floor(($b/256.0) * ($maxplus1-$min)) + $min;
}

for (;;) {
    my $lenbits = randvalue 0,14;
    my $len= (randbyteval << 8) | randbyteval;
    $len &= (1 << $lenbits)-1;
    my $data = randbytes $len;
    if (randbyteval >= 0x80) {
	$data =~ s{[\xc0\xdb]}{
            $& eq "\xc0" ? "\xcb\xdc" :
            $& eq "\xdb" ? "\xcb\xdd" :
            die
        }ge;
    }
    print "\xc0";
    print $data;
    STDOUT->flush;
}