From: "Thibaut Barrère" <thibaut.barrere@...>
Date: 2009-03-02T21:13:52+09:00
Subject: Using YAML for inter-process communication - anything built-in ?

Hi,

I'm just wondering - I implemented something (http://github.com/thbar/
petite-lettre/tree/master) I believe probably already exists, can
anyone tell me if it does ?

I'm using YAML to communicate using stdin/stdout between a Ruby MRI
process and a JRuby process (I will soon use it to communicate between
IronRuby and JRuby).

The parent process launches the child using:

PetiteLettre.call("ruby child_program.rb", { :command
=> :start_sale, :isbn => "1234567", :price => 12.4 })

and the child responds with:

PetiteLettre.receive do |message|
  response = {}
  if message[:command] == :start_sale
    # do something here
    raise "Price is too low" if message[:price] < 15.0
    response[:status] = "OK"
    response[:transaction_id] = "1235"
  else
    raise "Unknown command '#{message[:command]}'"
  end
  response
end

If something already exists in Ruby to do that this way, I'd like to
know about it.

Any idea ?

Thibaut
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