class PtyServer - dev-pty-screen-0.1.0 Documentation

Public Class Methods

new() click to toggle source

# File lib/server/pty_server.rb, line 15
def initialize
  @pty_m, @pty_s         = PTY.open
  @application_interface = ApplicationInterface.new @pty_m
  @screen_server         = ScreenServer.new App.options.screen_port
  @key_server            = KeyServer.new App.options.key_port, key_callback
  @pty_s.winsize         = [ App.options.rows, App.options.columns ]
  @application           = App.options.application
end

Public Instance Methods

key_callback() click to toggle source

# File lib/server/pty_server.rb, line 32
def key_callback
  ->(key){
    print key
    @application_interface << key
  }
end

screen_loop() click to toggle source

# File lib/server/pty_server.rb, line 39
def screen_loop
  Thread.new do
    loop {
      @screen_server.async.write @pty_m.readpartial( READSIZE )
    }
  end
end

start() click to toggle source

# File lib/server/pty_server.rb, line 24
def start
  initialize_pty
  @screen_server.listen
  @key_server.listen
  screen_loop
  spawn_application
end

Private Instance Methods

initialize_pty() click to toggle source

WTH? – Let me ‘splain: There a difference between the mode that PTY starts the terminal in, and the mode that terminal running the server is in.

This means the cursor moves around the screen on the server when you press the arrow keys, but when they are transmitted through the PTY to application, the escape encoding is different, this results in vim just honking at you and not moving the cursor.

By running ‘tput rmkx` from vim we are setting the PTY to cursor mode, and ta-dah, the arrows work again.

We have to go through vim, because there’s no instance of the PTY to talk to (PTY has only class methods) and there’s no running shell on the PTY to send commands to directly, so we have to use vim’s ‘!` to run `tput`.

Reference:

http://homes.mpimf-heidelberg.mpg.de/~rohm/computing/mpimf/notes/terminal.html
http://unix.stackexchange.com/questions/73669/what-are-the-characters-printed-when-altarrow-keys-are-pressed

Also, just for fun, in your terminal, pressing “ctrl+v” followed by any key will print the key codes, instead of running them. Try it with the enter/return key, you’ll see that it’s equal to ‘^m`. Now type a command and instead of hitting `enter`, press “ctrl+m”. Works just the same. That is just too cool.

# File lib/server/pty_server.rb, line 80
def initialize_pty
#   # `printf "\033?1h\033=" > #{@pty_s.path}`
#   @application_interface << ENTER_KEY
#   @application_interface << ":!tput rmkx"
#   @application_interface << ENTER_KEY
end

spawn_application() click to toggle source

# File lib/server/pty_server.rb, line 47
def spawn_application
  spawn(@application, in: @pty_s, out: @pty_s)
end