在Ruby中，在osx上，如何在ruby脚本中更改提示符？

require 'highline/import'

prompt = HighLine.new
prompt.say("Welcome to Ruby script!")

name = prompt.ask("Please enter your name: ") do |q|
  q.default = "Guest"
end

prompt.say("Hello, #{name}!")

# 修改提示符
prompt.prompt_text = "> "

age = prompt.ask("Please enter your age: ", Integer)

prompt.say("You are #{age} years old.")

gem install highline