Ruby - Problems with Expect and Pty

require 'pty'
require 'expect'

$expect_verbose = true
PTY.spawn("ssh [email protected]") do |reader, writer, pid|
  reader.expect(/[email protected]'s password:.*/)
  writer.puts("password")
  reader.expect(/.*/)
  writer.puts("ls -l")
  reader.expect(/.*/)
  answer = reader.gets
  puts "Answer = #{answer}"
end

Answer = .y's password:

require 'rubygems'
require 'net/ssh'

Net::SSH.start('your-server', 'username', :password => "password") do |ssh|
  puts ssh.exec!("ls -la")
end