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The TTY subsystem is central to the design of Linux, and UNIX in general. Unfortunately, its importance is often overlooked, and it is difficult to find good introductory articles about it. I believe that a basic understanding of TTYs in Linux is essential for the developer and the advanced user. Beware, though: What you are about to see is not particularly elegant. In fact, the TTY subsystem ” while quite functional from a user’s point of view ” is a twisty little mess of special cases. To understand how this came to be, we have to go back in time. ...

Random number generation is subtle. Random number generators contain deterministic algorithms designed to produce output that simulates non-deterministic behavior. It’s amazing that there are algorithms that do this well enough for many applications. But unless used carefully, random number generators can misbehave in mysterious ways. » John D. Cook | codeproject.com

Bajo la intensa mirada del telescopio espacial Kepler, van apareciendo ante nosotros más y más planetas similares al nuestro. Todavía no hemos encontrado uno exactamente igual que la Tierra, pero son tantos los descubiertos que parece que la galaxia debe estar llena de planetas habitables. Estos descubrimientos nos traen de nuevo una vieja paradoja. Tal como el físico Enrico Fermi, preguntó en 1950, si hay muchas sitios adecuados para la vida ahí fuera y las formas de vida extraterrestre pueden ser comunes, ¿dónde se han metido? Después de más de medio siglo de búsqueda de inteligencia extraterrestre, hasta el momento nos quedamos con las manos vacías. ...

There was a recent question about a PHP security checklist on a forum I frequent, and I’ve decided to write my own comprehensive checklist to fill the void. There’s something for everyone but the security expert. In fact, you might find an issue that you never thought about. Securing PHP web applications would be a better title for this article. » sk89q.com

We have been working hard the last several months to stop Restricted Boot, a major threat to user freedom, free software ideals, and free software adoption. Under the guise of security, a computer afflicted with Restricted Boot refuses to boot any operating systems other than the ones the computer distributor has approved in advance. Restricted Boot takes control of the computer away from the user and puts it in the hands of someone else. ...

We believe that a free and open Internet can bring about a better world. To keep the Internet free and open, we call on communities, industries and countries to recognize these principles. We believe that they will help to bring about more creativity, more innovation and more open societies. We are joining an international movement to defend our freedoms because we believe that they are worth fighting for. Let’s discuss these principles ” agree or disagree with them, debate them, translate them, make them your own and broaden the discussion with your community ” as only the Internet can make possible. ...

In every decent programmer’s toolbox lies a strange weapon called a Radix Sort. Where does it come from ? Who invented it ? I don’t know. As far as I can remember it was there, fast, easy, effective. Really effective. So unbelievably useful I’ve never really understood why people would want to use something else. The reasons ? Most of the time, they tell me about floats, negative values, and why their new quick-sort code rocks. ...

A lot of programmers that make some of the coolest and most useful software today, such as many of the stuff we see on the Internet or use daily, don’t have a theoretical computer science background. They’re still pretty awesome and creative programmers and we thank them for what they build. However, theoretical computer science has its uses and applications and can turn out to be quite practical. In this article, targeted at programmers who know their art but who don’t have any theoretical computer science background, I will present one of the most pragmatic tools of computer science: Big O notation and algorithm complexity analysis. As someone who has worked both in a computer science academic setting and in building production-level software in the industry, this is the tool I have found to be one of the truly useful ones in practice, so I hope after reading this article you can apply it in your own code to make it better. After reading this post, you should be able to understand all the common terms computer scientists use such as ”big O”, ”asymptotic behavior” and ”worst-case analysis”. ...

SKIP THE LICENSE Reading software licenses sucks, so we’ve summarized all of the popular ones for you in a neat at-a-glance format. Just begin typing the name of your license on the frontpage and select from the auto-completing drop-down menu. TL;DR - We summarize software licenses. LET THEM TAKE IT EASY Do you have people using your software? We all hate reading software licenses. Let them take it easy and link them to your license on here. We provide embed and linking options for every license on the site. Next time include a link alongside your license. TL;DR - Link a summary in place of a license. ...

Primeros pasos con Ubuntu 12.04 es una guía para principiantes del sistema operativo Ubuntu. Se encuentra disponible bajo una licencia de código abierto y su descarga, lectura, modificación y distribución son libres. El manual le ayudará a familiarizarse con tareas cotidianas como navegar por Internet, escuchar música, escanear documentos y mucho más. Al centrarse en instrucciones fáciles de seguir, es adecuado para todos los niveles de experiencia. » ubuntu-manual.org