Erlang for Beginners. Data Types, Variables, Lists and Tuples

Written by HaruAtari

Dear %username% , It’s the first article of the series. For many of you it may seem terribly trite as I’ll review the very basis of the subject. But this tutorial is going to be really useful for Erlang beginners. I’ll also dwell on some interesting things that aren’t obvious. In...

Premature Optimization is Evil

Written by Kukuruku Hub

There were no signs of trouble until we noticed a mix of 200 and 500 HTTP statuses in Kukuruku's web server logs. We were a bit confused when we started to look into it. The weird thing was that the server responded with either 200 ( OK ) or 500 ( Internal Server Error ) statuses even to requests...

Boost Concepts

Written by Vadim Androsov

I was always scared to use C++ templates due to the absence of standard mechanisms for setting parameter limits. In other words, when a developer writes the following function: template bool someFunc(T t) { if (t.someCheck()) { t.someAction(0); }...

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Writing a File System in Linux Kernel

Written by kmu1990
Who This Article is for There are no complex or difficult concepts in this article, all required is a basic knowledge of the command line, the C language, Makefile and a general understanding about file systems. In this article I am going to describe the components necessary for development inside the Linux kernel, then we’ll write the simplest loadable kernel module and, finally, write a framework for the future file system. It’s a module that will register quite a useful (for now) file system in the kernel. The ones familiar with development inside Linux kernel may not find anything interesting here. Introduction A file system is one of the central OS subsystems. File systems continue to develop as operating systems evolve. Currently we have an entire heterogenetic zoo of file systems, from the old “classic” UFS , to the new exotic NILFS (though this idea isn’t new at all,
*nix
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Brain Overclock or Internal Virtualization of Consciousness

Written by leon_3
Do you remember this movie? What is it doing here? Why the hell is such post on Kukuruku? I guess, because I think that the main component of IT is human, or rather our brain. I’ll tell you about another possibility of using your brain a bit more effectively. Everything described here has been tried out by me. It’s important to note that I’ll highlight if I haven’t tried something. I didn’t use any drugs or devices. Popular methods have only been used. And yes, it’s devastatingly realistic. Having tried it once, you'll never resist spreading the word. To avoid unnecessary cries in comments, I’m asking all staunch defenders of any religion or faith, and all the esoteric representatives to down-vote me and stop reading further. You’ll find no philosophy and great universal mysteries in this article. The rest of you are welcome — I’ll try to tell you about

J Can be Readable

Written by AraneusAdoro
You must be kidding me! It’s like programming using regular expressions… You’ll never make me do that again! I’m looking at the code and feel like an idiot. Isn’t it really an esoteric language like brain fuck? Does anyone really use it? And such programs can be read afterwards? quicksort=: (($:@(<#[), (=#[), $:@(>#[)) ({~ ?@#)) ^: (1<#) Perl is a trifle against it. About J language J — is a Korean of programming languages (may look confusing). It’s an explosion in reserved characters factory. Plenty of brackets, periods, slashes and it even works. It must be magic or something. Wanting to be short or just having been carried away some people writing on J forget even simple rules of any code writing. These rules aren’t new but they acquire a critical meaning as applied to APL similar languages. As when reading ((]i.~[:{.[){([:{:[),]`([:<[$:[:>])@.([:32&=[:3!:0[:>]))«2 0 construction even a trained brain is at

Running and Software Development

Written by Michael Dubakov
What can running and software development have in common? Nothing special at fist glance. A sweaty and slender runner totally differs from a flabby, bent by scoliosis programmer. Stadiums don’t applaud to developers and no one gives them the country flag for the lap of honor round the office after some release. Nevertheless, running and development do have many things in common. I have read a very difficult book — Surfaces and Essences . Douglas Hofstadter had a blast and I didn’t want to read the book after the first 50 pages. I literally forced myself to read few dozens of pages per week until I read till the third book – then I loved it. This book is about the way people think. They think in terms of analogies. Using millions of examples, Hofstadter and Sander quite clearly bring out the way analogies work and the things you can

Using Go to Execute Commands on Hundreds of Servers with SSH

Written by youROCK
In this article we’re going to write a simple program on Go (100 lines), which will execute commands via SSH protocol on hundreds of servers, and will do it quite efficiently. It will be implemented with the help of go.crypto/ssh , which is SSH protocol implementation by authors of Go. More “advanced” version of the program written in this article is available on github: GoSSHa (Go SSH agent). Introduction The company I work for has more than one server and in order to keep the work efficient libpssh library on the basis of libssh2 has been written. This library was written on C with libevent use many years ago, and it still copes with its tasks. One thing is that it’s quite complicate to maintain it. Go language from Google is getting more popular, as well as within our company. So I decided to rewrite libpssh with Go and fix
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JavaScript optimization challenge

Written by Няша Няшная
Hi, we're hosting the JS optimization challenge right now, with cash prizes and all. Link to full rules. The challenge: make JS strftime function very fast, and beat the performance of GNU libc's strftime . The slower code that can be used as a base for optimizations is here: github.com/mvasilkov/strftime You're free to use that source as the base of your solution. To make things interesting, we're not providing the reference benchmark. The benchmark will run on V8 (Node.js) engine. Send your solutions to [email protected] (as attachments, GitHub gists or whatever). Last date for submission is June 22, 2014. Winners will be announced on June 29.

Mocking with ScalaMock

Written by Kukuruku Hub

This article may be considered as a continuation of Introduction to Writing Tests with ScalaTest . In this post I would like to talk about ScalaMock. Mocking is a technique by which you can test code without requiring all of its dependencies in place. Java offers several frameworks for...

Scala
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Introduction to Writing Tests with ScalaTest

Written by Kukuruku Hub
To be able to quickly start visualizing some of the tests that can be written with ScalaTest, we can take advantage of the test-patterns-scala template from the Typesafe Activator . It consists of a number of examples that essentially target the ScalaTest framework. The easiest way to get the code is to download the template bundle for test-patterns-scala. An archive contains a bootstrap script that can simplify our life's by starting Activator automatically. Setting up the test-patterns-scala activator project only requires you to go to the directory where you installed the Typesafe Activator and then, either start the GUI through the > activator ui command, or type > activator new to create a new project and select the appropriate template when prompted. Download the bundle Extract the downloaded zip file `cd` to test-patterns-scala directory from your console Run ./activator ui You can also generate the project by running: ./activator new
Scala
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Mobile Typography

Written by Kukuruku Hub
As a designer you are probably keenly aware that more often than not, your dream font is not available on every device and every browser. Whether this knowledge is founded in the experience of designing and developing a site yourself, or from a horrifying experience such as your developer showing you the implementation of your design and feeling the special tug on your soul as part of you dies when viewing your original font choice rendered down into an abomination that makes comic-sans look vaguely desirable. Previously you may have even decided to give up the fight of using the perfect font for the entire site and opted to use it only on special portions of the design as an image. This, you tell yourself, will help you sleep at night and fix all the problems in the world as they can see the effort you have put into product

Browser Extension to Extract the Text from Images

Written by alizar
Naptha — is a very useful Chrome extension. It automatically recognizes text of all the images that are downloaded by the browser. With the help of this extension you can edit images text, select, copy and translate it. This extension is indispensable for copying the text from the document scans, photographs, posters, diagrams, charts, screenshots and even memes. The idea to create this extension was born on the basis of xkcd meme. It showed the websites, which didn’t allow selecting the text at their web-pages. Ironically, xkcd website can also be referred to “violators” as it doesn’t allow selecting the text inside the memes. Naptha extension fixes this drawback. Developers say that the Stroke Width Transform algorithm, which is used in the extension, can recognize a text even of incoherent flourishes. This peculiarity can be considered as a bug or a feature. By the way, Naptha works for any

Lytro Company Announced a Plenoptic Camera of the Second Generation

Written by ilya42
Lytro Company, founded by Ren Ng from Stanford University, is commercializing plenoptic photography. It’s a photo of the light field when matrix with the help of micro lens system fixes not a 2D image but full information of the scene light field — you can focus such images right after the shooting, and photos taken by this camera allow you to get a stereo image. The first Lytro camera looked more like a cute toy and shots quality was not that high. After rendering it into a 2D image its resolution was just a few mega pixels. The second generation camera, named Lytro Illym , looks much more like a real camera in both appearance and features. The size of the sensor has been increased from 1/3" to 1", images resolution is 40 Megaray (it’s the measurement for plenoptic cameras) compared to 11 in the first Lytro. 2D images

iOS holds you phone number hostage

Written by alizar

Benjamin Stein, technical manager at Mobile Commons, talks about the “ worst bug” that he has ever encountered. It happened once Ben changed his iPhone for an Android. Soon, he noticed that he is not receiving most of the messages from his contacts – other iPhone users. As it turned out,...

iOS
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IT digest for the last week

Written by alexzfort

Web Development nodegh.io — GitHub command line tools Best PHP IDE in 2014 How to use NoFollow tag Scrolling animations: examples, tutorials and jQuery plugins Slush — the streaming scaffolding system as a replacement for Yeoman WTF, HTML and CSS? Mobile Angular UI —...

Web fonts instruction for novice

Written by Kukuruku Hub

Choosing a font? Here is a simple scheme from Julian Hansen. The image is clickable. Just answer «yes» or «no». Fonts are pretty much standard, but I'm sure it can be quite useful for anyone.

USB Killer

Written by Dark Purple
It was a usual gloomy winter morning. My colleagues and I were drinking our morning coffee, sharing the news and there were no signs of trouble. But then a friend told about… (a quote from a chat in Skype): I read an article about how a dude in the subway fished out a USB flash drive from the outer pocket of some guy’s bag. The USB drive had “128” written on it. He came home, inserted it into his laptop and burnt half of it down. He wrote “129” on the USB drive and now has it in the outer pocket of his bag… A Picture to Attract Attention: Since I work in the company engaged in the development and manufacture of electronics, my colleagues and I are began to discuss options for creating a USB flash drive, that «would burn half a laptop down.» We had plenty of
DIY
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Secrets of the Conditional (ternary) Operator

Written by Alex Kulikov
Every self-respecting C/C++ programmer knows what the ternary operator is, and most everyone used it at least once in their programs. But do you know all the secrets of the ternary operator? What potential dangers are associated with its use and what features, seemingly not related to its direct purpose, it has? This article gives you the opportunity to test your knowledge and maybe learn something new. Let's start with a small test. Test Will the following code compile? Explain why. 1. int i; int j; (false ? i: j) = 45; 2. int i; int j; (true ? i: j) = 45; 3. short i; int j; (true ? i: j) = 45; 4. return true ? 0 : 1; 5. true ? return 0 : return 1; 6. What will be the output of the following piece of code? Why? std::cout << (false ? 9 : '9')
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