ssh.rb

require "open3"

commands = <<-EOS

echo 'foo'
cd /tmp
ls -1

EOS

threads = []

Open3.popen3("ssh -T localhost") do |stdin, stdout, stderr|
  threads << Thread.new do
    while line = stderr.gets
      $stderr.puts(line)
    end
  end
  
  threads << Thread.new do
    while line = stdout.gets
      $stdout.puts(line)
    end
  end

  commands.each_line do |line|
    stdin.puts(line)
  end

  stdin.close

  threads.each {|t| t.join }
end