From: khaines@...
Date: 2006-09-01T02:41:33+09:00
Subject: Re: Spawning daemon processes

On Fri, 1 Sep 2006, Thiago Arrais wrote:

> Is there any idiomatic way of doing that in Ruby that is platform 
> independent?

I'd just use Daniel Berger's win32utils:

http://rubyforge.org/projects/win32utils/

You need win32-process (which needs windows-pr) out of there, and then you 
can easily use create_process on Windows.  Here's one way that I use it to 
provide a method for spawning new processes that works where fork exists 
and on Windows, as well.

module IWATestSupport
   def self.create_process(args)
   # Takes a hash with two keys, :cmd and :dir.
   # :cmd is the command to execute, and :dir is the directory to
   # execute the command from.
     args[:cmd] = [args[:cmd]] unless args[:cmd].is_a?(Array)
     @fork_ok = true unless @fork_ok == false
     pid = nil
     begin
       raise NotImplementedError unless @fork_ok
       unless pid = fork
         Dir.chdir args[:dir]
         exec(*args[:cmd])
       end
     rescue NotImplementedError
       @fork_ok = false
       begin
         require 'rubygems'
       rescue Exception
       end

       begin
         require 'win32/process'
       rescue LoadError
         raise "Please install win32-process.\n'gem install win32-process' or http://rubyforge.org/projects/win32utils"
       end
       cwd = Dir.pwd
       Dir.chdir args[:dir]
       pid = Process.create(:app_name => args[:cmd].join(' '))
       Dir.chdir cwd
     end
     pid
   end
end


IWATestSupport.create_process({:dir => 'TC_CGI_Adaptor',
                                :cmd => [ruby,'-I../../../src','webrick.rb']})


There are a lot of very nice things in Dan's win32utils.


Kirk Haines