learnyounode

1-helloWorld.js

//Exercise 1

console.log('HELLO WORLD');

10-timeServer.js

//Exercise 10

var net = require('net');
var port = parseInt(process.argv[2]);
 
function thistime(){
  var date = new Date(Date.now());
  var hours = "0" + date.getHours();
  var minutes = "0" + date.getMinutes();
  var year = date.getFullYear();
  var day = "0" + date.getDate();
  var month = "0" + (date.getMonth() + 1);
 
  return year + "-" + month.substr(-2) + "-" + day.substr(-2) + " " + hours.substr(-2) + ':' + minutes.substr(-2) + "\n";
}
 
 
var server = net.createServer( function (socket) {
  socket.write(thistime());
  socket.end();
});
 
server.listen(port);

11-HTTPfileserver.js

//Exercise 11

var http = require('http');
var fs = require('fs');
 
var port = process.argv[2];
var filepath = process.argv[3];
 
var server = http.createServer( function (req,res){
  var src = fs.createReadStream(filepath)
  src.pipe(res);
})
 
server.listen(port);

12-uppercase.js

//Exercise 12

var http = require('http');
var map = require("through2-map");

var server = http.createServer( function callback (req,res) {
   if(req.method == "POST"){
    req.pipe(map(function (chunk){
      return chunk.toString().toUpperCase();
    })).pipe(res);
  }
 
});
 
server.listen(process.argv[2]);

13-jsonAPI.js

//Exercise 13

var http = require('http');
  var url = require('url');
  var portNumber = process.argv[2];
  http.createServer(function (req, res) {
    var urlObject = url.parse(req.url, true),
      pathname = urlObject.pathname,
      startTime = urlObject.query.iso,
      result;

    if (pathname === '/api/unixtime') {
      result = getUnixTimeStamp(startTime);
    } else if (pathname === '/api/parsetime') {
      result = getTimeObj(startTime);
    }

    if (result) {
      res.writeHead(200, {
        'Content-type': 'application/json'
      });
      res.end(JSON.stringify(result));
    } else {
      res.writeHead(404);
      res.end();
    }

  }).listen(portNumber)

  function getUnixTimeStamp(startTime) {
    return {
      unixtime: getTimeStamp(startTime)
    };
  }

  function getTimeStamp(startTime) {
    return Date.parse(startTime);
  }

  function getTimeObj(startTime) {
    var date = new Date(getTimeStamp(startTime));
    return {
      hour: date.getHours(),
      minute: date.getMinutes(),
      second: date.getSeconds()
    };
  }



  /*var http = require('http');
  var url = require('url');

  function parsetime (time) {
    return {
      hour: time.getHours(),
      minute: time.getMinutes(),
      second: time.getSeconds()
    }
  }

  function unixtime (time) {
    return { 
        unixtime : time.getTime()
    }
  }

  var server = http.createServer(function (req, res) {
  var parsedUrl = url.parse(req.url, true);
  var time = new Date(parsedUrl.query.iso);
  var result

    if (/^\/api\/parsetime/.test(req.url)){
      result = parsetime(time);
    }else if (/^\/api\/unixtime/.test(req.url)){
      result = unixtime(time)
    }
    if (result) {
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify(result));
    } else {
      res.writeHead(404);
      res.end();
    }
  })
  server.listen(Number(process.argv[2]));*/

2-babySteps.js

//Exercise 2

var result = 0

    for (var i = 2; i < process.argv.length; i++) {
      result += num(process.argv[i])
    }
    console.log(result);

3-myFirstIO.js

//Exercise 3

var fs = require('fs');

var filePath = process.argv[2];
var output = fs.readFileSync(filePath);
output = output.toString().split('\n');
console.log(output.length - 1);


/*var fs = require('fs');

    var contents = fs.readFileSync(process.argv[2]);
    var lines = contents.toString().split('\n').length - 1;
    console.log(lines);*/

4-asyncIO.js

//Exercise 4
var fs = require('fs');
var file = process.argv[2];

output = fs.readFile(file, function callback(err, data) { 
  if (err) {
        return console.log(err);
      }
console.log(data.toString().split('\n').length - 1);
});

5-filtered.js

//Exercise 5

var fs = require('fs');

var path = require('path');

var ext = process.argv[3];
var dir = process.argv[2];

fs.readdir(dir, function callback(err, list){
    if(err){
        console.log(err);
    }
    for(var i = 0; i < list.length; i++){
        var file = path.extname(list[i]);

        if(file == "."+ext){
            console.log(list[i]);
        }
    }
})



/*
var fs = require('fs')
    var path = require('path')

    var folder = process.argv[2]
    var ext = '.' + process.argv[3]

    fs.readdir(folder, function (err, files) {
      if (err) return console.error(err)
      files.forEach(function (file) {
        if (path.extname(file) === ext) {
          console.log(file)
        }
      })
    })
*/

6-modFirst.js

//Exercise 6-01
var fs = require('fs');
var path = require('path');
module.exports = function (dir, fileString, callback) {
    fs.readdir(dir, function (err, list) {
        if (err){
            return callback(err);
        }
        list = list.filter(function (file) {
            return path.extname(file) === '.' + fileString;
        })
        callback(null, list);
    })
}

6-modSecond.js

//Exercise 6-02
var filterFn = require('./modFirst.js');
var dir = process.argv[2];
var filterStr = process.argv[3];

filterFn(dir, filterStr, function (err, list) {
    if (err){
        return console.error( err);
    }
    list.forEach(function (file) {
        console.log(file);
    })
})

7-HTTPclient.js

//Exercise 7

var http = require('http');
var urlPath = process.argv[2];
http.get(urlPath, function callback(response) {
    response.setEncoding('utf8');
    response.on('data', function(data){
        console.log(data);
    })
});



/*var http = require('http');
var url = process.argv[2].toString();
http.get(url, function (response) {
    response.setEncoding('utf8');
    response.on('data', console.log);
    response.on('error', console.error);
}).on('error', console.error);*/

8-HTTPcollect.js

//Exercise 8

var http = require('http');
var urlPath = process.argv[2];
var allData= "";

http.get(urlPath, function callback (response){
    response.setEncoding("utf8");
    response.on("data", function(data){
        allData = allData + data;
    })
    response.on("end", function(){
        console.log(allData.length);
        console.log(allData);
    })
});


/*var http = require('http');
var bl = require('bl');
http.get(process.argv[2], function (response) {
    response.pipe(bl(function (err, data) {
        if (err){
            return console.error(err);
        }    
        data = data.toString();
        console.log(data.length);
        console.log(data);
    }))
})*/

9-asyncJuggling1.js

//Exercise 9

var http = require('http');
var bl = require('bl');
 
var urls = [];
var completed = 0;
var all = [];
for(var i=2; i < process.argv.length; i++){
	urls.push(process.argv[i]);
}
 
for(i in urls){
  getdata(i);
}
 
function getdata(count){
	http.get(urls[count],function(response){
		response.pipe(bl(function(err, data){
      if(err) {
      	return console.error(err);
      	}	
      data = data.toString();
      all[count] = data;
      completed++;
      if (completed == urls.length) publish();
    }));	
	})
}
 
function publish(){
  if(completed < urls.length) return false;  for(i in all){
    console.log(all[i]);
  }
}