How to Debug One of the painful parts of teaching a lab-based embedded systems course is that over and over I have to watch a team with a relatively simple bug in their code, but who is trying to fix it by repeatedly making random changes. Generally they start with code that’s pretty close to working and break it worse and worse. By the end of the lab they’re frustrated, aren’t any closer to finding the bug, and have made a complete mess of their code, forcing them to go back to the previous day or week’s version. A typical Computer Science curriculum fails to teach debugging in any serious way. First we’ll want to define some terms: The high-level reason debugging is hard is that it’s an inverse problem: it attempts to infer the cause for observed effects. Of course, a very bad bug will involve several of these factors at the same time. The following steps constitute a fairly complete approach to debugging. 1. It makes no sense to even start debugging unless we’re pretty sure: 2. 3. 4. 5. 6. 7. 8.
64 Things Every Geek Should Know - laptoplogic.com The term ‘geek’, once used to label a circus freak, has morphed in meaning over the years. What was once an unusual profession transferred into a word indicating social awkwardness. As time has gone on, the word has yet again morphed to indicate a new type of individual: someone who is obsessive over one (or more) particular subjects, whether it be science, photography, electronics, computers, media, or any other field. A geek is one who isn’t satisfied knowing only the surface facts, but instead has a visceral desire to learn everything possible about a particular subject. A techie geek is usually one who knows a little about everything, and is thus the person family and friends turn to whenever they have a question. 1. USB – Universal Serial Bus GPU – Graphics Processing Unit CPU – Central Processing Unit SATA – Serial ATA HTML – Hyper-text Markup Language HTTP – Hypertext Transfer Protocol FTP – File Transfer Protocol P2P – Person to Person data sharing 2. 3. Here’s what one looks like: 4.
Ruby on Rails Guides 7 Unique Ways To Practice Your Coding Skills I am 24 years old and just started learning coding. I want to be a programmer. Am I too late in the game? One of the upvoted answers to this on Quora.com came from graphic artist Michel Poisson. I’m 63, and eight months ago I decided to teach myself Blender 3D. The 40 years between the respondent and the doubter is the chink in our thought process that says it’s a young man’s game. If you have picked up a programming language to learn, let’s start the class with some innovative websites. Dash – Learn With Projects Learn: HTML, CSS, JavaScript Dash is similar to Codecademy with its immersive project-based approach, and the tutorials walk you through five projects of increasing difficulty. Dash is designed for incremental learning – you cannot go to the next skill unless you unlock the previous one. The Code Player – Learn From Screencasts Learn: HTML5, CSS3, JavaScript. Learning with screencasts from coders is another interesting take on how to build something with code. Learn: Python
Netflix Open Sources “Resilience Engineering” Code Library Hystrix: it’s the genus name for “Old World” porcupines, and it’s also the latest release from Netflix. But you won’t see it in their catalog of movie and TV titles, and you can’t add it to your queue, because it’s not content–it’s how Netflix makes sure its content is highly available. Now, Netflix has made Hystrix open source, for anyone using Amazon Web Services (AWS) to implement in their own cloud applications. Read on for details on this “resilience engineering” code library. Mention Netflix, and most people will think of the company’s DVD-rental-by-mail service or its growing library of “Watch Instantly” streaming video titles. This week, Netflix added Hystrix to its bag of open-source tricks. The Hystrix home page on GitHub defines the problem: [R]unning an application that depends on 30 services that each have 99.99% uptime we get: 99.9930 = 99.7% uptime 0.3% of 1 billion requests = 3,000,000 failures 2+ hours downtime/month even if all dependencies have excellent uptime.
Топики / Избранное / Хабрацентр им. marchevsky Недавно я прочитал о том, что Гэйб Ньюэлл всерьёз настроен на то, чтобы перенести хорошие и качественные игры в Linux. Как он считает, это именно то, чего не хватает, и что на данный момент ограничивает развитие платформы. Безусловно, он прав. Тем не менее, лично для меня есть и другая область, которая мне даже намного важнее, чем игры — это музыка. На картинке — рабочее место Niels Ott, на компьютере запущен Ardour. Моя жена тоже музыкант, и когда она увидела, какие секвенсоры и синтезаторы есть в Linux — она даже не стала пытаться в них разобраться, просто вернувшись к своим Cubase и Reason. Я же, пользуясь Linux уже около 10 лет, не могу так просто отказаться от того, чтобы хотя бы пробовать имеющиеся программы.
Code School - Try Git Using Git To use Git on the command line, you will need to download, install, and configure Git on your computer. You can also install GitHub CLI to use GitHub from the command line. For more information, see "About GitHub CLI." If you want to work with Git locally, but do not want to use the command line, you can instead download and install the GitHub Desktop client. If you do not need to work with files locally, GitHub lets you complete many Git-related actions directly in the browser, including: Setting up Git Download and install the latest version of Git.Note: If you are using a Chrome OS device, additional set up is required:Install a terminal emulator such as Termux from the Google Play Store on your Chrome OS device.From the terminal emulator that you installed, install Git. Authenticating with GitHub from Git When you connect to a GitHub repository from Git, you will need to authenticate with GitHub using either HTTPS or SSH. Connecting over HTTPS (recommended) Connecting over SSH
IoC container solves a problem you might not have but it’s a nice problem to have | Krzysztof Koźmic on software On frameworks and libraries A logging framework helps you log what's happening in your application. A UI framework helps you render and animate UIs to the user. All of these tasks and concepts are pretty easy to understand. Also the code of your application changes in order to use those frameworks and libraries. What about IoC container? So what about inversion of control containers? I got one of the IoC containers, put it in my application, and then all hell broke loose. Let's ignore the details for now and concentrate on the wider sentiment. So? The sentiment is one of confusion, scepticism and frustration. Truth is, those aren't necessarily the right questions to ask. I have seen applications where introducing a container immediately, would only worsen things. What sort of architecture are we talking about? Container has certain requirements in order to work smoothly. That's a lot of assumptions, isn't it? It's the inversion! The i-word
Введение PowerShell и администрирование будущего Долгое время визитной карточкой Windows служил графический интерфейс, а желающим поработать в консоли приходилось довольствоваться весьма урезанным функционально cmd.exe. Появление PowerShell с гибким языком сценариев изменило ситуацию к лучшему. Используя его возможности, можно легко выполнить практически любую задачу, возникающую перед администратором. Зачем админу PowerShell? Если настройку при помощи графических утилит можно назвать наглядной, то консоль вырывается вперед, когда говорят об автоматизации задач и обработке большого количества данных. Ранее админу, чтобы упростить себе работу, необходимо было использовать командные BAT-файлы, VBScript, JavaScript, Windows Script Host, Perl и прочие инструменты, позволяющие управлять системной информацией. Сейчас PowerShell встроен в Win2k8/R2/Se7en и доступен как опциональный компонент для WinXPSP2/2k3/Vista. Начинаем исследование PS> Get-Process | Sort CPU -Descending | Select -First 10 Все просто! PS> Get-PSDrive PS> cd HKLM: PS HKLM>
VARK: A REVIEW OF THOSE WHO ARE MULTIMODAL Recently my views about those who are multimodal have been extended. Here is my current thinking. Multimodal preferences dominate the database for all populations and it is clearly the most used set of preferences when making decisions about learning. Usually one third of respondents are in the four-part VARK set and another large group are in the groups who have three or two preferred modalities. This dominance can seem disappointing as some people feel that their special characteristics have been lumped into a largely undistinguished category and inappropriately recognized. It also means that teachers, trainers and coaches may be at odds as to how they might help people those people. Context Specific Approach Those who have a multimodal approach to learning and decision-making are now seen in two groups with an indistinct boundary or transition between them. Whole-Sense Approach Some, may criticize them for taking a long time to make a decision. Sequencing
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