Commadn gist

function resolved(arg) {
  console.log('New arg is: ' + arg);
}

function otherCommand(command, argParse, resolve) {
  this.errFlag  = false;
  this.command  = command;
  this.argParse = argParse;
  this.resolve  = resolve;
}

otherCommand.prototype.error = function(arg) {
  console.log('There was an error: ' + arg);
}

otherCommand.prototype.run = function(arg) {
  var input = arg.toString().trim();
      param = parseInt(input, 10);

  param = this.argParse(param);

  if(!this.errFlag) {
    this.resolve(param);
  } else {
    this.errFlag = false;
    this.error(param);
  }
};

var myOtherCommand = new otherCommand('open', function(arg) {
    if(arg !== 0) {
      this.errFlag = true;
      return arg;
    } else {
      arg++;
      return arg;
    }
  }, resolved);


process.stdout.write('Please provide input: ');
process.stdin.on('data', function(data) {
  myOtherCommand.run(data);
});