ruby随机在控制台显示字符串

require 'curses'
module Curses
def self.program
main_scr=init_screen
noecho
cbreak
curs_set(0)
main_scr.keypad=true
yield main_scr
end
end
Curses.program do |scr|
max_x=scr.maxx
max_y=scr.maxy
100.times do
scr.setpos(rand(max_y),rand(max_x))
scr.addstr("hi")
end
scr.getch
end