Ruby Net SSH

require 'rubygems'
require 'net/ssh'
require 'etc'

server ='localhost'

def ssh_exec!(ssh, command)
  stdout_data =""
  stderr_data =""
  exit_code =nil
  exit_signal =nil
  ssh.open_channel do|channel|
    channel.exec(command)do|ch, success|
      unless success
        abort "FAILED: couldn't execute command (ssh.channel.exec)"
      end
      channel.on_data do|ch,data|
        stdout_data+=data
      end

      channel.on_extended_data do|ch,type,data|
        stderr_data+=data
      end

      channel.on_request("exit-status")do|ch,data|
        exit_code = data.read_long
      end

      channel.on_request("exit-signal")do|ch, data|
        exit_signal = data.read_long
      end
    end
  end
  ssh.loop
  [stdout_data, stderr_data, exit_code, exit_signal]
end

Net::SSH.start(server,Etc.getlogin)do|ssh|
  puts ssh_exec!(ssh,"true").inspect
  # => ["", "", 0, nil]

  puts ssh_exec!(ssh,"false").inspect  
  # => ["", "", 1, nil]