Bash demo in browser

A couple of years ago I made a live Bash demo using JavaScript and Q. Those not familiary with Q should get aquainted as the that Javscript library has some awesome functionality for asynchronous promises.

Click here for a fully functional open source demo..

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/q.js/1.0.0/q.js"></script>
<div id="wnd"></div>
<div id="log"></div>

<textarea rows="11" cols="50">
% cat example.c
#include <stdio.h>
int main()
{
  printf("Goodbye Cruel World!\n");
  return 0;
}
% make example.c -o example
% ./example
Goodbye Cruel World!
</textarea>

CSS

body {
  background: black;
}
#wnd {
  background: #232;
  border-radius: .2em;
  white-space: pre-wrap;
  padding: .5em;
  font-family: "Consolas", "Ubuntu Mono", "Monaco", monospace;
  color: white;
}
.prompt {
  color: #99aaee;
}
.cmd {
  color: #9e9e9C;
}

JQuery

var prompt;

function setPrompt(usr, domain)
{
  prompt = usr + '@' + domain + ' %';
}

function addOutput(s) {
  $('<div>').text(s).appendTo(wnd);
  return Q.delay(100);
//  return addPrompt();
}

function addInput(s) {
  var l = $('.prompt:last');
var e = $('<span>').addClass('cmd').appendTo(l);
    
  return addLettersRecursive(e, s);
}

function addPrompt() {
  var l = $('<div>').text(prompt).addClass('prompt').appendTo(wnd);
  return Q.delay(900);
}

function addLettersRecursive(container, s) {
  container.append(s.charAt(0)); // dangerous 😦
  var row_complete = Q.defer();
  Q.delay(100).then(function() {
    if (s.length <= 1) {
      row_complete.resolve();
    }
    addLettersRecursive(container, s.substr(1)).then(function() {
      row_complete.resolve();
    })
  });
  return row_complete.promise;
}

$( document ).ready(function() {
  $('textarea').hide();
  
  setPrompt('inge', 'sparkledb.net');
  
  var lines = $('textarea').val().split('\n');
  
  var promise = new Q();
  
  promise = promise.then(function() 
  {  
    lines.forEach( function(item) {
      if (item[0] == '%')
      {
        promise = promise.then(function() 
        { return addPrompt(); })
        promise = promise.then(function() 
        { return addInput(item.substr(1)); })
      }
      else
      {
        promise = promise.then(function() 
        { return addOutput(item); })
      }
    })
  })
  promise.done();
  
});