script.rb

require 'curses'

p $stdin.tty?
p $stdin.read
Curses.init_screen
Curses.clear
Curses.refresh

begin
  Curses.setpos(6, 3)  # column 6, row 3
  Curses.addstr("Hello")
  Curses.getch  # Wait until user presses some key.
ensure
  Curses.close_screen
end

$ echo "hi" | ruby script.rb
false
"hi\n"

$ ruby script.rb
true
Waits for input
Draws curses screen