This is just killing me.   I need to do a bunch of shell commands in parallel.
I want to get the output if there is any.   I have tried Thread.New,
but contrary to the docs, I can't seem to use an instance variable to pass 
data out of the thread.  Globals work.   I want my node object to have access 
to this command output, but in order to execute in parallel I have to use 
threads or fork.   I have tried passing instance and local variables into the 
thread explicitly ala Thread.new(@myvar) or Thread.new(myvar).

def command ( the_command )
    t = Thread.new do
        sin, sout, serr =  Open3.popen3( the_command )
      sout.each_line { |line| puts line }  # prints output to stdout
      @instanceVar = sout.readlines # get output into array
      sout.close
    end # of Thread

	print @instanceVar  # instanceVar is unchanged.

  end # def command