Shell commands

/* Status and element functions. */
var e = function(tag,index){ return demotab.getElementsByTagName(tag)[index||0]; };
var status = function(msg) {
  if (!msg) return e('p').style.display = 'none';
  e('p').style.display = '';
  e('p').innerHTML = msg;
};
 
/* Setup demo */
var setup = function() {
  e('form').onsubmit = function(event) {
    try {
      if (!trephine || !trephine.loaded) throw "Error: trephine not loaded.";
      if (!trephine.hasPermission()) throw "Error: elevated permissions have not been granted.";
      var cmds = parse(e('input').value);
      for (var i=0; i<cmds.length; i++) cmds[i] = cmds[i].replace('\\', '\\\\').replace("\n",'\\n').replace('"', '\\"');
      var result = trephine.exec( 'js', 'java.lang.Runtime.getRuntime().exec(["' + cmds.join('", "') + '"])' );
      var boxtype = result.success ? 'success' : 'error';
      e('div').innerHTML = '<p class="' + boxtype + 'box" style="float:none">' + (result.result || result.error) + '</p>';
    } catch(err) {
      e('div').innerHTML = '<p class="errorbox" style="float:none">' + err + '</p>';
    }
    return false;
  };
};
 
/* Load trephine */
status('<span class="spinner"></span> Loading trephine...');
trephine.load({
  debug: true, // Enables debug logging to the Java Console
  engines: ['js'], // Initialize the JavaScript engine as soon as possible
  onload: function() { // Immediately prompt for permissions
    status('<span class="spinner"></span> Asking for elevated permissions...');
    trephine.askPermission( function(response) {
      if (!response) { // Short-circuit if permission request was denied
        return demotab.innerHTML = '<div class="error">Sorry, you must grant trephine privileges to enjoy this demo.</div>';
      }
      setup();
      status('Permission request granted.');
      setTimeout( function(){ status(); }, 2000 );
    } );
  }
});
 
/* Command line argument parser */
var parse = function(s) {
  var re = function(s,o) { return new RegExp(s,o) };
  var args = [], ws = re('\\s'), quote = re('[\'"]'), escape = '\\\\';
  var machine = {
    'search': function(ch) { // Looking for a value
      if (ch.match(ws)) return;
      if (ch.match(escape)) return this.state = 'leadescape';
      var d = ch.match(quote);
      this.delimiter = d ? d[0] : ws;
      this.buffer = [d ? '' : ch];
      this.state = 'value';
    },
    'leadescape': function(ch) { // Excape character encountered outside a value
      this.buffer = [ch.match(ws) ? ch : '\\' + ch];
      this.delimiter = ws;
      this.state = 'value';
    },
    'value': function(ch) { // Inside a value
      if (ch.match(escape)) return this.state = 'escape';
      if (!ch.match(this.delimiter)) return this.buffer.push(ch);
      args.push(this.buffer.join(''));
      this.buffer = [];
      this.state = 'search';
    },
    'escape': function(ch) { // Escape character
      var m = ch.match(this.delimiter);
      this.buffer.push( m ? m[0] : '\\' + ch);
      this.state = 'value';
    }
  };
  for (var i=0; i<s.length; i++) machine[machine.state || 'search'](s.substr(i,1));
  if (machine.buffer && machine.buffer.length) args.push(machine.buffer.join(''));
  return args;
};