nic_training/CoreModules.js

Sample demos for training on nodejs

//CoreModules.js
var http = require("http");//http is a core module that allows to handle http requests made by the user...
var fs = require("fs");
/******************Using http***************************
function postErrorPage(res){
	res.writeHead(404,{'Content-type':'text/text'})
	res.write("Oops! Some thing happened. Will come back to U");
	res.end();
}
http.createServer(function(req, res){
	
	if(req.method == 'GET' && req.url =='/'){
		console.log(req);
		res.writeHead(200, {'Content-type':'text/html'});
		fs.createReadStream("./HomePage.html").pipe(res);
	}else{
		postErrorPage(res);
	}
}).listen(1234);
******************Using file system************************/
function readFile() {
	fs.readFile('firstExample.js', 'utf8', function(err, res){
		if(err){
			console.log(err.message);
		}else{
			console.log(res)
		}
	});
}


//readFile is used to read a file asynchronously. It has a callBack function that can be used to read the data after the file is read.

fs.open('MyFile.txt','a+', function(err, fd){
	var buffer = new Buffer("Sample Content to add");
 fs.write(fd, buffer, 0, buffer.length, null, function (err, written) {
 	console.log(written);
 	fs.close(fd, ()=>console.log("Completed"));
 });
});

/*var contents = fs.readFileSync('modules.js', 'utf8');//File reading synchronously...
console.log(contents);
readFile();
*/