Class: Pssh::Pty

Inherits:
Object
  • Object
show all
Defined in:
lib/pssh/pty.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Pty

Returns a new instance of Pty.



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# File 'lib/pssh/pty.rb', line 12

def initialize
  @stream = ''
  set_command
  clear_environment
  Thread.new do
    begin
      @read, @write, @pid = PTY.spawn(@command)
      @write.winsize = $stdout.winsize
      if new?
        system("clear")
        pssh = <<-BANNER
# [ pssh terminal ]
# Type `exit` to terminate this terminal.
BANNER
        $stdout.puts pssh
        Signal.trap(:WINCH) do
          resize!
        end
        system("stty raw -echo")
      end
      @active = true
      while @active do
        begin
          io = [@read]
          io << $stdin if new?
          rs, ws = IO.select(io)
          r = rs[0]
          while (data = r.read_nonblock(2048)) do
            if new? && r == $stdin
              @write.write_nonblock data
            else
              $stdout.write_nonblock data if new?
              data.encode!('UTF-16', 'UTF-8', :invalid => :replace, :replace => '')
              data.encode!('UTF-8', 'UTF-16')
              if data.valid_encoding?
                store data
                Pssh.socket.write data
              end
            end
          end
        rescue Exception => e
          if @active
            if e.is_a?(Errno::EAGAIN)
              retry
            else
              system("stty -raw echo") if new?
              puts 'Terminating Pssh.'
              Kernel.exit!
              @active = false
            end
          end
        end
      end
    end
  end
end

Instance Attribute Details

#attach_cmd ⇒ Object (readonly)

Returns the value of attribute attach_cmd.



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# File 'lib/pssh/pty.rb', line 10

def attach_cmd
  @attach_cmd
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/pssh/pty.rb', line 9

def path
  @path
end

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/pssh/pty.rb', line 7

def pid
  @pid
end

#read ⇒ Object (readonly)

Returns the value of attribute read.



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# File 'lib/pssh/pty.rb', line 4

def read
  @read
end

#stream ⇒ Object (readonly)

attr_reader :write



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# File 'lib/pssh/pty.rb', line 6

def stream
  @stream
end

Instance Method Details

#clear_environment ⇒ Object 



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# File 'lib/pssh/pty.rb', line 69

def clear_environment
  ENV['TMUX'] = nil
  ENV['STY'] = nil
end

#existing? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pssh/pty.rb', line 78

def existing?
  @existing_socket
end

#new? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pssh/pty.rb', line 74

def new?
  !existing?
end

#resize! ⇒ Object

Public: Resizes the PTY session based on all the open windows.

Returns nothing.



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# File 'lib/pssh/pty.rb', line 122

def resize!
  winsizes = Pssh.socket.sessions.values.map { |sess| sess[:winsize] }
  winsizes << $stdout.winsize if new?
  y = winsizes.map { |w| w[0] }.min
  x = winsizes.map { |w| w[1] }.min
  @write.winsize = [ y, x ]
end

#send_display_message(user) ⇒ Object

Public: Sends a message to the tmux or screen display notifying of a new user that has connected.

Returns nothing.



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# File 'lib/pssh/pty.rb', line 134

def send_display_message(user)
  if @existing_socket
    case Pssh.command.to_sym
    when :tmux
      `tmux -S #{@path} display-message "#{user} has connected"`
    when :screen
      `screen -S #{@path} -X wall "#{user} has connected"`
    end
  end
end

#set_command ⇒ Object 



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# File 'lib/pssh/pty.rb', line 82

def set_command
  case Pssh.command.to_sym
  when :tmux
    if ENV['TMUX']
      @path = ENV['TMUX'].split(',').first
      @existing_socket = true
      @command = "tmux -S #{@path} attach"
    else
      @path = "/tmp/#{Pssh.default_socket_path}"
      @command = "tmux -S #{@path} new"
    end
    @attach_cmd = "tmux -S #{@path} attach"
  when :screen
    if ENV['STY']
      @path = ENV['STY']
      @existing_socket = true
      @command = "screen -S #{@path} -X multiuser on && screen -x #{@path}"
    else
      @path = Pssh.default_socket_path
      @command = "screen -S #{@path}"
      puts @command
    end
    @attach_cmd = "screen -x #{@path}"
  else
    @path = nil
    @command = ENV['SHELL'] || (`which zsh` && 'zsh') || (`which sh` && 'sh') || 'bash'
  end
end

#store(data) ⇒ Object

Internal: Store data to the stream so that when a new connection is started we can send all that data and give them the visual.

Returns nothing.



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# File 'lib/pssh/pty.rb', line 149

def store(data)
  @stream << data
  @stream = @stream[-Pssh.cache_length..-1] if @stream.length > Pssh.cache_length
end

#write(data) ⇒ Object

Public: Writes to the open stream if they have access.

Returns nothing.



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# File 'lib/pssh/pty.rb', line 114

def write(data)
  @write.write_nonblock data if Pssh.io_mode['w']
end