Posts in 2013

 

The Birth of Standard Error

Earlier today Stephen Johnson, in a mailing list run by the The Unix Heritage Society, described the birth of the standard error concept: the idea that a program's error output is sent on a channel different from that of its normal output. Over the past forty years, all major operating systems and language libraries have embraced this concept.

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The Frictionless Development Environment Scorecard

The environment we work in as developers can make a tremendous difference on our productivity and well-being. I’ve often seen myself get trapped in an unproductive setup through a combination of inertia, sloth, and entropy. Sometimes I put-off investing in new, better tools, at other times I avoid the work required to automate a time-consuming process, and, also, as time goes by, changes in my environment blunt the edge of my setup. I thus occasionally enter into a state where my productivity suffers death by a thousand cuts. I’ve also seen the same situation when working with colleagues: cases where to achieve a simple task they waste considerable time and energy jumping through multiple hoops.

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A Better Air Gap

Bruce Schneier recently published ten rules for setting up an air-gapped computer; a computer that even the NSA can't hack, because it's not connected to the internet. His rules are practical and make sense, but, given the number of vulnerabilities regularly found in modern operating systems, I think that they need strengthening.

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Differential Debugging

If estimating the time needed for implementing some software is difficult, coming up with a figure for the time required to debug it is nigh on impossible. Bugs can lurk in the most obscure corners of the system, or even in the crevices of third-party libraries and components. Ask some developers for a time estimate, and don’t be surprised if an experienced one snaps back, “I’ve found the bug when I’ve found the bug.” Thankfully, there are some tools that allow methodical debugging, thereby giving you a sense of progress and a visible target. A method I’ve come to appreciate over the past few months is differential debugging. Under it, you compare a known good system with the buggy one, working toward the problem source.

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Portability: Goodies vs. the hair shirt

“I don’t know what the language of the year 2000 will look like, but I know it will be called Fortran”

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Impact Factor of Computer Science Journals 2012

The Thomson Reuters Web of Knowledge has published the 2012 Journal Citation Reports. Following similar studies I performed in the past six years (2007, '08, '09, '10, '11, '12) here is my analysis of the current status and trends for the impact factor of computer science journals.

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How to Create Your Own Git Server

Although I'm a happy (also paying) user of GitHub's offerings, there are times when I prefer to host a private repository on a server I control. Setting up your own Git server can be useful if you're isolated from the public internet, if you're subject to inflexible regulations, or if you simply want features different from those offered by GitHub (and other similar providers). Setting up a Git server on a Unix (Linux, Mac OS X, *BSD, Solaris, AIX) machine isn't difficult, but there are many details to observe. Here is a complete guide.

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How to make a MacBook Kensington Lock Adapter

Apple, in its infinite wisdom, has not included a Kensington lock slot in the current model of the MacBook Pro computer. Given the computer's price, desirability, and the fact that three people I know have had theirs stolen, I decided to build an improvised adapter that would allow me attach a Kensington lock to the computer. I realize, that the security offered by such a contraption is what my colleague Vassilis Prevelakis calls an "advisory lock", for Kensington locks can be easily picked or pried away. However, I think it might deter a casual thief who would snatch the laptop you've left unattended for a couple of minutes.

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Systems Software

Systems software is the low-level infrastructure that applications run on: the operating systems, language runtimes, libraries, databases, application servers, and many other components that churn our bits 24/7. It’s the mother of all code. In contrast to application software, which is constructed to meet specific use cases and business objectives, systems software should be able to serve correctly any reasonable workload. Consequently, it must be extremely reliable and efficient. When it works like that, it’s a mighty tool that lets applications concentrate on meeting their users’ needs. When it doesn’t, the failures are often spectacular. Let’s see how we go about creating such software.

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How to Fix the Sony MDR-W08L Headphones

I love the Sony MDR-W08L headphones, because they are featherlight and the only ones that don't fall from my ears when I run. Sadly, there's no effective strain relief at the point where the cable leaves their body. As a result the cable can become internally severed, and the sound becomes intermittent. Here's how to fix this problem.

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Software Tools Research: SPLASH Panel Discussion

Written by Dennis Mancl and Steven Fraser

At the recent SPLASH (Systems, Programming, Languages and Applications: Software for Humanity) conference, one of us (Steven Fraser) organized an international group of experts to discuss challenges in software tools research.1 The panelists included Kendra Cooper (University of Texas, Dallas), Jim “Cope” Coplien (Gertrud & Cope), Junilu Lacar (Cisco Systems), Ruth Lennon (Letterkenny Institute of Technology), Diomidis Spinellis (Athens University of Economics and Business), and Giancarlo Succi (Free University of Bolzano-Bozen).

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Systems Code

If I program in many high and low-level languages, but donít write systems code, I am a quiche programmer or a code monkey. And if my code runs without errors, and I know the complexity of all algorithms; and if my servers have hundreds of cores and gigabytes of RAM, but donít write systems code, I am nothing. And if I run the hippest kernel, and install the neatest apps, but donít write systems code, it profiteth me nothing.

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The Importance of Being Declarative

A declarative programming style focuses on what you want your program to do rather than how to perform the task. Through diverse programming techniques, libraries, and specialized languages, you end up with code that sidesteps nitty-gritty implementation details, dealing instead with a task’s big picture.

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