REPL for nodeJS as function of app

repl.js

var readline = require('readline');
var trustedEval = eval;
var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

rl.prompt(true);
rl.on('line', function (cmd) {
    if (((cmd || '').replace(/\s*/g, '')) === '') {
        rl.prompt();
        return;
    }
    if (cmd.toUpperCase() == 'EXIT') {
        rl.close();
    } else {
        try {
            console.log(trustedEval('(' + cmd + ')'));
        } catch (error) {
            console.log(error.toString());
        }
        rl.prompt();
    }
});