This dirty dirty preamble allows you to drop a ruby script into a cronfile...it will kill the previous incarnation...so lame it is awesome

daemonesque_preamble.rb

# kill the process if it is running
PIDFILE = "/var/run/stream_load.pid"

def read_pidfile
  begin
    File.open(PIDFILE,"r") { |file| return file.gets.to_i }
  rescue
    puts "pidfile not found or invalid"
  end if File.exists?(PIDFILE)
  puts "no pidfile readable"
  nil
end

def verify_pid pid
  puts pid
  %x"ps p #{pid}".each_line do |line|
    puts line
    if(line =~ /#{Regexp.escape(__FILE__)}/)
      puts "pid is valid"
      return true
    end
  end
  puts "pid is INvalid or process isn't running"
  return false
end

pid = read_pidfile
unless pid.nil?
  if verify_pid(pid)
    puts "killing pid"
    Process.kill "KILL", pid
  else
    puts "pid no longer valid"
  end
else
  puts "pid not found"
end

File.open(PIDFILE,"w") do|file|
  puts "writing pid"
  file.print Process.pid
end

# now start doing important things....
while true 
  echo "awesome"
end