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Tristan Louis gives weight to new term that I like a lot: fauxpen. Faux in French means "false" or "fake". So fauxpen means fake open. There has always been a lot of that going around, but since the world of tech inevitably contains more of everything, there's more fauxpen stuff than ever. In his post Tristan issues a fresh warning about some of what he calls "a venus flytrap of technology". His d

As of today, Linux Journal is back, and operating under the ownership of Slashdot Media. As Linux enthusiasts and long-time fans of Linux Journal, we were disappointed to hear about Linux Journal closing its doors last year. It took some time, but fortunately we were able to get a deal done that allows us to keep Linux Journal alive now and indefinitely. It's important that amazing resources like

Linux Journal's very first issue featured an interview between LJ's first Publisher, Robert Young (who went on to co-found Red Hat among other things), and Linus Torvalds (author of the Linux kernel). After 25 years, we thought it'd be interesting to get the two of them together again. You can read that first interview from 1994 here. Interview: Linus Torvalds and Robert Young Robert Young: It is

Today Bloomberg reports GitHub was acquired by Microsoft, the announcement being made as early as Monday. "GitHub preferred selling the company to going public and chose Microsoft partially because it was impressed by Chief Executive Officer Satya Nadella, said one of the people, who asked not to be identified discussing private information." Bloomberg goes on to say, "Terms of the agreement weren

The Red Hat family of operating systems addressed Meltdown and Spectre in its v3.10 kernel quickly, but relied too much upon Intel's flawed microcode and was forced to revert from a complete solution. Oracle implemented alternate approaches more suited to its v4.1 UEK, but both kernels continue to lack full Spectre coverage while they wait for Intel. Conspicuously absent from either Linux branch i

Talk about a Happy New Year. The reason: it turns out we're not dead. In fact, we're more alive than ever, thanks to a rescue by readers—specifically, by the hackers who run Private Internet Access (PIA) VPN, a London Trust Media company. PIA are avid supporters of freenode and the larger FOSS community. They’re also all about Linux and the rest of the modern portfolio of allied concerns: privacy,

[Updated: LJ is back!] Linux Journal Ceases Publication On January 1, 2018 Linux Journal was saved and brought back to life by a company called London Trust Media, the parent company of Private Internet Access. The comeback issue of Linux Journal has a release date of March 15, 2018. The article below, originally published in early December of 2017, is preserved for history. EOF It looks like we’r

Key Considerations for Software Updates for Embedded Linux and IoT The Mirai botnet attack that enslaved poorly secured connected embedded devices is yet another tangible example of the importance of security before bringing your embedded devices online. A new strain of Mirai has caused network outages to about a million Deutsche Telekom customers due to poorly secured routers. Many of these embed

Download the complete ebook now. Clicking this link will start the download. I first heard the term “machine learning” a few years ago, and to be honest, I basically ignored it that time. I knew that it was a powerful technique, and I knew that it was in vogue, but I didn’t know what it really was— what problems it was designed to solve, how it solved them and how it related to the other sorts of

Because you're a reader of Linux Journal, you probably already know that Linux has a rich virtualization ecosystem. KVM is the de facto standard, and VirtualBox is widely used for desktop virtualization. Veterans should remember Xen (it's still in a good shape, by the way), and there is also VMware (which isn't free but runs on Linux as well). Plus, there are many lesser-known hypervisors like the

Packet queues are a core component of any network stack or device. They allow for asynchronous modules to communicate, increase performance and have the side effect of impacting latency. This article aims to explain where IP packets are queued on the transmit path of the Linux network stack, how interesting new latency-reducing features, such as BQL, operate and how to control buffering for reduce

A vDSO (virtual dynamic shared object) is an alternative to the somewhat cycle-expensive system call interface that the GNU/Linux kernel provides. But, before I explain how to cook up your own vDSO, in this brief jaunt down operating system lane, I cover some basics of vDSOs, what they are and why they are useful. The main purpose of this article is to illustrate how to add a custom vDSO to a Linu

If you follow my columns in Linux Journal, you probably are aware that I'm a big fan of the command line. When it comes to getting things done efficiently, most of the time the command line can't be beat. This has led me to integrating services like instant messaging and Twitter into BitlBee so I can use them with my command-line IRC client Irssi (both written up in previous LJ issues). You probab

I've been a sysadmin for a long time, and part of being a sysadmin is doing more than is humanly possible. Sometimes that means writing wicked cool scripts, sometimes it means working late, and sometimes it means learning to say no. Unfortunately, it also sometimes means cutting corners. I confess, I've been "that guy" more than once. A good example is SELinux. On more than a few (hundred!) occasi

December 2013's EOF, titled "Mars Needs Women", visited an interesting fact: that the male/female ratio among Linux Journal readers, and Linux kernel developers, is so lopsided (male high, female low) that graphing it would produce a near-vertical line. I was hoping the piece would invite a Linux hacker on the female side of that graph to step up and move the conversation forward. And sure enough,

This month, Bill and I take on one of the classic holy wars between Linux geeks: /opt vs. /usr/local. If you look at the current Linux Filesystem Hierarchy Standard, you will see that both /opt and /usr/local are represented there. If you read further, you will see that they both seem to have a similar purpose: a place to put software that's not part of the standard system. Even though both direct

Nowadays, high-performance server software (for example, the HTTP accelerator) in most cases runs on multicore machines. Modern hardware could provide 32, 64 or more CPU cores. In such highly concurrent environments, lock contention sometimes hurts overall system performance more than data copying, context switches and so on. Thus, moving the hottest data structures from a locked to a lock-free de

Virtualization is now a staple of the modern enterprise. As more and more shops switch to the virtual paradigm, managing those new virtual resources is a critical part of any deployment. For admins using Microsoft- or VMware-based hypervisors, powerful management tools are available to keep their virtual houses in order. Unfortunately, those products and their accompanying tools come with a hefty

Ditch your laptop and code in the cloud—it's easier than you'd think. On September 19, 2011, I said goodbye to my trusty MacBook Pro and started developing exclusively on an iPad + Linode 512. This is the surprising story of three months spent working in the cloud. Figure 1. iPad on Sofa It all started when I bought my first MacBook a couple years ago; despite a decade using Linux, I never really

One of the fundamental features that makes Linux and other Unices useful is the “pipe”. Pipes allow separate processes to communicate without having been designed explicitly to work together. This allows tools quite narrow in their function to be combined in complex ways. A simple example of using a pipe is the command: ls | grep x When bash examines the command line, it finds the vertical bar cha

An Introduction to GCC Compiler Intrinsics in Vector Processing Speed is essential in multimedia, graphics and signal processing. Sometimes programmers resort to assembly language to get every last bit of speed out of their machines. GCC offers an intermediate between assembly and standard C that can get you more speed and processor features without having to go all the way to assembly language: c

I don't know whether a picture is really worth a thousand words (most pictures seem to be considerably larger these days), but when I give talks about Perl, I often put up a picture showing where some of the ideas in Perl come from. I usually make a joke about Linguistics not really being the opposite of Common Sense, and then proceed to talk a lot about both of them, with some Computer Science th

Most modern operating systems are designed to try to extract optimal performance from underlying hardware resources. This is achieved mainly by virtualization of the two main hardware resources: CPU and memory. Modern operating systems provide a multitasking environment that essentially gives each task its own virtual CPU. The task generally is unaware of the fact that it does not have exclusive u

An Introduction to Application Development with Catalyst and Perl Catalyst is the latest in the evolution of open-source Web development frameworks. Written in modern Perl and inspired by many of the projects that came before it, including Ruby on Rails, Catalyst is elegant, powerful and refined. It's a great choice for creating any Web-based application from the simple to the very complex. Like m

The first time you connect to a newly installed MariaDB or PostgreSQL database, you need to connect as the database superuser because you likely have not set up any other users. To launch a freshly installed MariaDB mysql client, do the following: mysql -u root -p You will be prompted for the password you entered during the package install process. To launch a freshly installed PostgreSQL psql cli

This article should acquaint you with basic Arduino programming and show you how to write programs that interact with objects in the real world. (A mandatory disclaimer: the last time I really studied electronics was way back in high school, so this article focuses more on the programming aspects, rather than the electronic side of things.) Physical Computing Before I start talking about this real

The votes are in, the tallies are counted, the hanging chads have been evaluated, and we have our winners. This year holds a few surprises, a couple dominant players and as much open source as you can handle. We don't encourage gambling here at Linux Journal, but if you had an office pool going for pizza money, it's officially too late to make your wager.

Have you ever wondered how Google, Facebook and other Internet giants process their massive workloads? Billions of requests are served every day by the biggest players on the Internet, resulting in background processing involving datasets in the petabyte scale. Of course they rely on Linux and cloud computing for obtaining the necessary scalability and performance. The flexibility of Linux combine