nvasilakis

We've received various questions on Ed and during hours about `ECONN...` errors. We've put together a short tips and tricks doc to help you debug these. These errors often come from subtle race-conditions.

### ECONNREFUSED

The message's recipient's HTTP server is not running at all at the time the message was sent. Examine whether you check for the recipient to start, then have the sender send a message. In other words, you are (a) starting the recipient node too late or (b) closing it too early.

### ECONNRESET

The message's recipient shut down during communication. This indicates that you are shutting down the recipient node too early. Typically, this error appears in tests because the done is misused. If done is called too early, you will get a `ECONNRESET`. 

nvasilakis

GNU Screen Cheat Sheet

Basics

Remember: in screen, all screen-related commands are prefixed by ctr-a (which means pressing ctrl and a together, and then pressing the followup character).

The 4 most basic commands (if you're new to screen, learn only these):

• ctrl-a c -> create­ate new window
• ctrl-a ctrl-a -> toggle between latest windows
• ctrl-a " -> show all windows and choose using up/down arrows
• ctrl-a d -> detach window

nvasilakis

{
  "scripts": {
    "build": "tsc && npm run post-build",
    "watch": "tsc-watch --onSuccess 'npm run post-build'",
    "post-build": "rollup build/index.js --o build/bundle.js --f iife && cat src/prelude.js build/bundle.js | (pbcopy && osascript -e 'display notification \"Script copied to clipboard\" with title \"Script Builder\"' || echo 'copied script to clipboard')"
  }
}

nvasilakis

x = "thisIsASecret";
function unsafeMain () {
  var v = require('./0.vuln.js');
  v.f()
}

unsafeMain();

nvasilakis

// http://stackoverflow.com/questions/7505623/colors-in-javascript-console
// https://github.com/adamschwartz/log
// color-console
(function() {
    var exportedLog, ffSupport, formats, getOrderedMatches, hasMatches, isFF,
        isIE, isOpera, isSafari, log, makeArray, operaSupport, safariSupport,
        stringToArgs, _log;

    if (!(window.console && window.console.log)) {
        return;

nvasilakis

function memoize(fun) {
  // memoize a function with arbitrary arguments
  var memo = {}
  var name = fun.name || "anonymous";
  return function memoize_fun() {
    this.name = this.name + "__" + name;
    var args = arguments;
    var sargs = JSON.stringify(args);
    if (memo[sargs]) {
      return memo[sargs];

nvasilakis

FROM ubuntu

RUN apt-get update
RUN apt-get install -y socat

VOLUME /foo

CMD socat UNIX-LISTEN:/foo/bar.sock -

nvasilakis

/*
   A simple new-line delimited JSON protocol with upgrades.

   Receiving Usage:

     protocol = require('./frame-protocol');

     // parsing data
     parser = protocol.Parser();

nvasilakis

/**
 * A mini tutorial on JavaScript Object Inheritance
 *
 * API myPerson = person.create() creates a person object
 * myPerson.id set/get ID
 * myPerson.name set/get name
 * myPerson.age set/get age
 * myPerson.salute() return a salute (incl. name)
 * person.staticSalute() returns a static salute (no name)
 *

nvasilakis

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;