simple example of using pipe, fork, and exec

command.rb

class Command
  attr_accessor :pull, :push

  def initialize(name, *args)
    @name, @args, @pull, @push = name, args, *IO.pipe
  end

  def exec
    fork do
      pull.close
      $stdout.reopen(push)
      Kernel.exec @name, *@args
    end
    push.close
    pull.read.split("\n")
  end
end

touch = Command.new("touch", "tmp/foobar")
ls = Command.new("ls", "-ahl", "tmp")

touch.exec
ls.exec.grep /ba/
#=> ["-rw-------  1 u40141 40141    0 2013-04-22 23:43 foobar"]