Nodeschool.io - learnyounode

1-hello-world.js

console.log("HELLO WORLD");

10-file-server.js

const http = require('http')
const fs = require('fs')

const filename = process.argv[3]

const server = http.createServer(function (req, res) {
  res.writeHead(200, { 'content-type': 'text/plain' })

  fs.createReadStream(filename).pipe(res);
})

server.listen(Number(process.argv[2]))

11-http-upper.js

const http = require('http');
const map = require('through2-map');

const uc = map((chunk) => {
  return chunk.toString().toUpperCase();
});

const server = http.createServer((req, res) => {
  if (req.method !== 'POST') {
    return res.end('send me a POST\n')
  }

  req.pipe(uc).pipe(res);
});

server.listen(process.argv[2]);

12-http-json.js

const http = require('http')
const url = require('url')

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

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

const server = http.createServer((req, res) => {
  const parsedUrl = url.parse(req.url, true)
  const time = new Date(parsedUrl.query.iso)
  let 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-baby-steps.js

let sum = 0;

for(let i = 2; i < process.argv.length; i++){
  sum = sum + Number(process.argv[i]);
}

console.log(sum);

3-my-first-io.js

const fs  = require('fs');

const str = fs.readFileSync(process.argv[2]).toString();

console.log(str.split('\n').length - 1);

4-my-first-io-async.js

const fs = require('fs');

const file = process.argv[2];

fs.readFile(file, (err, contents) => {
  // fs.readFile(file, 'utf8', callback) can also be used
  if (err) {
    return console.log(err)
  }

  const lines = contents.toString().split('\n').length - 1
  console.log(lines);
});

5-filtered.js

const fs = require('fs')
const path = require('path')

const folder = process.argv[2]
const ext = `.${process.argv[3]}`

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

6-http-client.js

const http = require('http')
const url = process.argv[2]

http.get(url, (response) => {
  response.setEncoding('utf8')
  response.on('data', console.log)
  response.on('error', console.error)
}).on('error', console.error)

7-http-collections.js

const http = require('http')
const bl = require('bl')

const bufferList = bl((err, data) => {
  if (err) {
    return console.error(err)
  }
  data = data.toString()
  console.log(data.length)
  console.log(data)
})

http.get(process.argv[2], (response) => {
  response.pipe(bufferList)
})

8-juggling-async.js

const http = require('http')
const bl = require('bl')
let results = []
let count = 0

function printResults () {
  for (let i = 0; i < 3; i++) {
    console.log(results[i])
  }
}


function httpGet(index) {
  http.get(process.argv[2 + index], (response) => {
    response.pipe(bl((err, data) => {
      if (err) {
        return console.error(err)
      }

      results[index] = data.toString()
      count++

      if (count === 3) {
        printResults()
      }
    }))
  })
}

for (var i = 0; i < 3; i++) {
  httpGet(i)
}

9-http-server-time.js

const net = require('net')

function zeroFill (i) {
  return (
    i < 10 ? '0' : ''
  ) + i
}

function now () {
  const d = new Date()
  return d.getFullYear() + '-' +
    zeroFill(d.getMonth() + 1) + '-' +
    zeroFill(d.getDate()) + ' ' +
    zeroFill(d.getHours()) + ':' +
    zeroFill(d.getMinutes())
}

const server = net.createServer(function (socket) {
  socket.end(now() + '\n')
})

server.listen(Number(process.argv[2]))