vt.js

vt.js: A reusable VT Emulator written in NodeJS.

vt.js can be useful for:

• Writing a terminal emulator
• Writing a terminal multiplexer

vt.js was largely inspired by existing VT emulation projects including:

• Google's hterm: http://goo.gl/3i5AJ
• @chjj's tty.js: http://github.com/chjj/tty.js/
• Suckless' st: http://st.suckless.org/

Example Usage

var pty = require('pty.js');

var pty = require('pty.js').spawn('bash', [], {
  name: 'xterm-color',
  cols: 80,
  rows: 30,
  cwd: process.env.HOME,
  env: process.env
});

var term = require('vt.js').term({ 
  pty: pty,
  cols: 80,
  rows: 30
});

term.on('refresh', function(dirty, slice, cursor) {
  /* ... */
});
term.on('alternate', function(is_alt) {
  /* ... */
});
term.on('title', function(title) {
  /* ... */
});
term.on('resize', function(cols, rows) {
  /* ... */
});

/* var buffer = term.buffer(); */
/* var title = term.title();   */
/* var mode = term.mode();     */
/* var cusror = term.cursor(); */

/* term.resize(120, 40);       */

Architecture

vt.js is composed of two main software component:

• vt: which is the core part of the VT emulation. It receives the stream of data coming directy form the pty and translates VT10x character sequences into events that it emits. The list of events emitted can be found in the file lib/vt.js.

• term: term interprets the events received by vt (without knowledge of VT10x character sequences) and interprets them to maintain the state of the current buffer, scrollback buffer and cursor. It itself emits simple events on refresh, alternate (mode), title change, and resize. It can easily be used for rendering of the screen in any given UI system.

Todo

• Extend test suite
• Handle all vttest corner cases
• Optimize refresh semantics

License

Copyright (c) 2013, Stanislas Polu. All rights reserved. MIT License. (see LICENSE file)