#!/usr/bin/perl

# noise[.pl] v2001.0622 Chris Pressey
# Fairly realistic line noise simulator.
# Usage: [perl] noise[.pl] [average-long-delay-in-seconds] &

# Copyright (c)2001, Chris Pressey, Cat's Eye Technologies.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
#  1. Redistributions of source code must retain the above copyright
#     notices, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notices, this list of conditions, and the following disclaimer in
#     the documentation and/or other materials provided with the
#     distribution.
#  3. Neither the names of the copyright holders nor the names of their
#     contributors may be used to endorse or promote products derived
#     from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
# COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

### BEGIN noise[.pl] ###

$bk = 30;
if(defined($arg = shift @ARGV))
{
  $bk = 0+$arg;
}

### MAIN ###

$| = 1;
while(1)
{
  $rv = int(rand(1) * ($bk/3) - $bk/3);
  sleep $bk + $rv;
  $cy = int(rand(1) * 8) + 1;
  for($i=1;$i <= $cy; $i++)
  {
    $cc = int(rand(1) * 12) + 1;
    for($j=1; $j <= $cc; $j++)
    {
      print chr(int(rand(1) * 256));
    }
    $sp = int(rand(1) * 3) + 1;
    sleep $sp;
  }
}

### END of noise[.pl] ###