read/write Node.js

// read file
var fs = require('fs');
var path = require('path');

fs.readFile(path.join(__dirname, '/data/customers.cvs'), {encoding: 'utf-8'}, function(err, data) {
    if (err) throw err;
    console.log(data);
});


// write file
var fs = require('fs');
fs.writeFile('message.txt', 'Hello world', function(err) {
    if (err) throw err;
    console.log('Writing is done');
});