From: ara.t.howard@...
Date: 2005-12-03T06:04:20+09:00
Subject: Re: Problem with method that starts process, yields pid then yields return code

On Fri, 2 Dec 2005, x1 wrote:

> I'm trying to create a method that will kick off a new process, return it's
> pid.. while allowing the return code to also be captured for later
> examination..  [on windows platform]

should work, but untested on windows:

   harp:~ > cat a.rb

   require "thread"
   class Exec
     %w( cmd queue pipe pid thread exitstatus ).each{|a| attr_accessor a}
     def initialize cmd
       self.cmd = cmd
       self.queue = ::Queue::new
       self.thread =
         ::Thread::new(queue) do |q|
           pipe = ::IO::popen cmd
           q.push pipe
           q.push pipe.pid
           begin
             loop{ stdout = pipe.gets or break }
             pipe.close
             q.push $?.exitstatus
           rescue => e
             q.push e
           end
         end
       self.pipe = queue.pop
       self.pid = queue.pop
       self.exitstatus = nil
     end
     def wait
       self.exitstatus = self.queue.pop
     end
     def self::[](*a, &b) new *a, &b end
   end

   require "yaml"

   y "start" => Time::now
   sleep = Exec[ " ruby -e' sleep 2 and exit 42 ' " ]
   y "cmd" => sleep.cmd
   y "pid" => sleep.pid
   y "exitstatus" => sleep.wait
   y "finish" => Time::now

   harp:~ > ruby a.rb
   ---
   start: 2005-12-02 14:03:29.920649 -07:00
   ---
   cmd: " ruby -e' sleep 2 and exit 42 ' "
   ---
   pid: 19947
   ---
   exitstatus: 42
   ---
   finish: 2005-12-02 14:03:31.930995 -07:00


kind regards.

-a
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