Ruby 从长时间运行的进程中捕获并显示标准输出文本

我正在使用Ruby脚本启动一个长时间运行的进程，该进程定期将信息发送到STDOUT。例如：

Open3.popen3("tail  -f ./test_file") do |stdin, stdout, stderr|
  # continually read text that the tail command sends to it's STDOUT and
  # send that text to *this* process's STDOUT
  #
  # Tried the following but it doesn't work
  #
  while !stdout.eof?
    puts stdout.read
  end
end

#!/usr/bin/env ruby

io_obj = IO.popen('tail -f ./test_file')

while !io_obj.eof?
  # read a line of text at a time
  result = io_obj.readline

  puts result
end