From: Jim Freeze <jim@...>
Date: 2005-11-08T02:06:26+09:00
Subject: Re: Daemons written in ruby...

A while back there was some discussion about daemons.
As I recall, there was a list of 5 things that one needed
to do to have a 'correct' daemon, but I never saw it in
Ruby code.

Below is what I have used, and it has worked for my needs,
but it may have problems in some environments because I
am missing 4 of the 5 requirements.

I would love to see this standardized and put in the stdlib,
or made into a gem.

  def start_daemon(do_print = false)
    if (child_pid = fork)
      STDERR.puts "PID #{child_pid}" if do_print
      exit
    end
    Process.setsid
  end

 def run
    # daemonize the process
    start_daemon
 end


On 11/7/05, Steve [RubyTalk] <steve_rubytalk@shic.co.uk> wrote:
> I've written a simple daemon as a ruby script... it writes all
> interesting output to a log file and is intended to be a long-running
> process as opposed to a program which executes only while a user is
> logged in.
>
> In C I'd have closed stdin, stdout and stderr; dissociate my process
> from its parent then called fork in order to return 0 indicate
> successfully starting the daemon.
>
> What is the best way to achieve this in Ruby?  I can achieve the end
> result I want using nohup, but I'm sure there must be a neater way.
>
--
Jim Freeze