"tail -f" for ruby

tail-and-quit.rb

require 'open3'
def tail_and_quit(filename, regex_to_match)
  cmd = "tail -n0 -f #{filename}"  # bash tail -f command
  Open3.popen2e('bash', '-c', cmd) do |i,oe,t|  # input, output/error, process 
    oe.each do |line|
      puts line
      break if line.match(/#{regex_to_match}/)
    end
    Process.kill('INT', t.pid)  # kill the tail process after matching string
  end
end