thread_loop.rb

require 'redis'
require 'open3'
class Finder
  def redis
    Redis.new
  end

  def listen_for_terminate(id)
    Thread.new do
      loop do
        puts 'checking'
        if redis.get("terminate:#{id}")
          puts "KILL!!!!"
          redis.del("terminate:#{id}")
          Process.kill('INT', Process.pid)
        end
        sleep 0.5
      end
    end
  end

  def perform
    Open3.popen3('find ~') do |stdin, stdout, stderr, wait_thr|
      puts stdout.read
    end
  end
end

Finder.new.tap do |train|
  train.listen_for_terminate(1)
  train.perform
end