syncAsync.js

//sync v/s async

//Count # of lines
var fs = require('fs')

var fileName = process.argv[2]

//Async call
fs.readFile(fileName,function (err, data) {
    lst_ = data.toString();
    console.log(lst_.split('\n').length - 1);
});

//Sync call
buffer_ = fs.readFileSync(fileName);
len_ = buffer_.toString().split('\n').length - 1;
console.log(len_)