Put the fun back in computing. With this weekend's reading, we encourage you to build yourself an internet radio station, create your own Audible or even live-stream your pets on YouTube. Sky's the limit with Linux. Enjoy!

Building Your Own Audible

by Shawn Powers

I have audiobooks from a variety of sources, which I've purchased in a variety of ways. I have some graphic audio books in MP3 format, a bunch of Audible books in their DRM'd format and ripped CDs varying from m4b (Apple format for books) to MP3 and even some OGG. That diversity makes choosing a listening platform difficult. Here I take a quick look at some options for streaming audio books.

Linux Gets Loud

by Joshua Curry

Linux is ready for prime time when it comes to music production. New offerings from Linux audio developers are pushing creative and technical boundaries. And, with the maturity of the Linux desktop and growth of standards-based hardware setups, making music with Linux has never been easier.

Using gphoto2 to Automate Taking Pictures

by Shawn Powers

With my obsession—er, I mean hobby—regarding BirdCam, I've explored a great number of camera options. Whether that means trying to get Raspberry Pi cameras to focus for a macro shot of a feeder or adjusting depth of field to blur out the neighbor's shed, I've fiddled with just about every webcam setting there is. Unfortunately, when it comes to lens options, nothing beats a DSLR for quality. Thankfully, there's an app for that.

Creating an Internet Radio Station with Icecast and Liquidsoap

by Bill Dengler

Ever wanted to stream prerecorded music or a live event, such as a lecture or concert for an internet audience? With Icecast and Liquidsoap, you can set up a full-featured, flexible internet radio station using free software and open standards.

Live Stream Your Pets with Linux and YouTube!

by Shawn Powers

Anyone who reads Linux Journal knows about my fascination with birdwatching. I've created my own weatherproof video cameras with a Raspberry Pi. I've posted instructions on how to create your own automatically updating camera image page with JavaScript. Heck, I even learned CSS so I could make a mobile-friendly version of BirdCam that filled the screen in landscape mode.

Nativ Vita

by James Gray

The /boot partition sometimes needs a bit of attention. If you enable automatic updates, it will fill up with old kernels that you'll probably never need. It also will stop you from running aptitude to install or remove anything. If you find yourself in this situation, you can use dpkg to get around it. dpkg is the higher-level package manager in Debian-based distributions, and it's very useful when aptitude has broken.

To see the status of your partitions run: df -h:

Filesystem      Size  Used Avail Use% Mounted on
udev            3.0G   12K  3.0G   1% /dev
tmpfs           597M  528K  597M   1% /run
/dev/dm-0        97G   14G   78G  15% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
none            5.0M     0  5.0M   0% /run/lock
none            3.0G     0  3.0G   0% /run/shm
none            100M     0  100M   0% /run/user
/dev/sda1       228M  219M     0 100% /boot

If you look in the directory /boot you will see it full of old kernels and images. it is not advisable to just delete them as you can break your system. Run the following command, this will tell you what kernel you are currently on: uname -r:

3.13.0-137-generic

Lets find out what kernels are installed and which ones can be purged from your system. To do this, run the following:

dpkg --list "linux-image*" | grep -v $(uname) | grep ii

This will use dpkg to list all linux kernel images excluding the one you are using, that is installed.

The output might still be quite big, let's refine it by piping the results in to awk. The awk command below is an instruction to print the second column from the output.

dpkg --list "linux-image*" | grep -v $(uname -r) |
 ↪grep ii | awk '{ print $2 }'

This gives us a list to work with. We can stick this in a script or run it from the command line to purge them all.

CAUTION: make sure that the kernel you are using is not in the list. We should have eliminated that when we specified grep -v $(uname -r). The -v part tell grep exclude anything that contains the output of uname -r.

If you are happy and have sudo privileges, go ahead:

sudo dpkg --purge $(dpkg --list "linux-image*" | grep -v
 ↪$(uname -r) | grep ii | awk '{ print $2 }')

To finish off run sudo update-grub2 - This will ensure grub is updated with the available kernels - otherwise you may be heading for trouble. Then fix aptitude by running: sudo apt-get -f install followed by sudo apt-get autoremove to clear the images out of aptitude.

Look at your partition you will see it has free space.

Could the world's idle computers make the $200 billion cloud computing industry obsolete?

In the final years of the Obama administration, it seemed that the world was witnessing the emergence of an odd alliance between the largest establishment tech companies and the traditionally anti-establishment community of independent techies. The highest profile case involved Apple and other major corporations siding with civil rights organizations to advocate against weakening device encryption on behalf of law enforcement, and it it led to a hope that these companies were finally seeing the profit potential in having secure, satisfied customers. That hope has now evaporated in the face of continuous betrayals of user trust, and rather than take it lying down, tech users are looking into alternative solutions that put them in control.

The recently passed federal Clarifying Lawful Overseas Use of Data Act, or the CLOUD Act, makes it perfectly clear why this shift away from self-interested stakeholders is so necessary. The new law was motivated by a legal demand for Microsoft to hand user data to US law enforcement, even though that data was stored outside US borders and, thus, in a different legal jurisdiction. At first, it seemed that Microsoft was planning to stand up for privacy and national sovereignty by opposing the demand in court—but, predictably, the corporation rolled over just as soon as it deemed that its own interests were protected.

The goal of the CLOUD Act is for the US to be able to compel any company that does business in the country to provide information to US law enforcement, even if that information is not actually stored within the US. If it's successful, a company's willingness to fight will become essentially irrelevant. It makes all cloud computing and cloud storage companies suspect, simply by virtue of being cloud computing companies.

Groups like the Electronic Frontier Foundation and the American Civil Liberties Union believe it also could allow US law enforcement to seize information in foreign jurisdictions because those regions have more lenient privacy laws than the US itself. The reverse, in which foreign law enforcement agencies operating under more stringent rules than the US, could gain access to protected information stored in the country, is also a major concern.

On this week's "Cooking with Linux (without a Net)" show, Marcel learns, in as much as he can learn anything, that you can try to do too many things at once—especially when those things really don't all want to happen at the same time. Before I continue, let me point out that this is a recording of a live show that takes place every Tuesday at 12 noon, Eastern time. We cover lots of different ways to virtualize including VirtualBox, command-line kvm, the dangers of not getting permission, AQemu, GNOME boxes, virt-manager, Xen and lots more. We also give ArcoLinux another shot and in that process, bite off a desktop environment that Marcel knows nothing about, i3.

On this week's "Cooking with Linux (without a Net)" show, Marcel learns, in as much as he can learn anything, that you can try to do too many things at once—especially when those things really don't all want to happen at the same time. Before I continue, let me point out that this is a recording of a live show that takes place every Tuesday at 12 noon, Eastern time. We cover lots of different ways to virtualize including VirtualBox, command-line kvm, the dangers of not getting permission, AQemu, GNOME boxes, virt-manager, Xen and lots more. We also give ArcoLinux another shot and in that process, bite off a desktop environment that Marcel knows nothing about, i3.

This year was a big one for companies like Canonical and Slack. It also was a big year for technologies that Canonical created to enable third-party application support—specifically, the snap package.

I'm sure most, if not all, of you have heard about this package manager. In fact, it's been around since at least 2014, but it initially was developed around Canonical's Ubuntu phone operating system. Now, although the phone operating system has since been canceled, snaps continue to dominate the operating system, in both the server and desktop space.

What Is a Snap?

A "snap" application package is a self-contained piece of software, and although it originally was designed to be hosted on Ubuntu, the package will work across a range of other Linux distributions. This isn't your traditional APT or YUM manager hosting DEB and RPM (or other) package formats.

Again, the appeal to snap packages is that they are self-contained (that is, containerized). They are designed to auto-update and are safe to run. A snap package is bundled with its dependencies, which is what allows it to run on all other major Linux distribution without any modification. It also doesn't have any dependency to any package manager or application store. But, don't misunderstand this—a package manager or application store still can host one or more snap packages; however, the snap package is not dependent to that manager.

Snapcraft is the official tool for software developers to package their software programs in a Snap format.

Sitting Down with Canonical and Slack

Earlier this year on January 18th, Canonical announced the first iteration of Slack as a snap. But, why was this announcement so important? I recently had the pleasure of sitting down with Evan Dandrea of Canonical and Felix Riesberg of Slack. They gave me the answers I was looking for.

Evan's team at Canonical builds the platform to make everyone's life easier—that is, Snapcraft. And Felix's team leverages that very same platform to bring wonderful applications, such as Slack, to your Linux desktop.

First, for those not familiar with Slack, it's an enterprise software platform that allows teams and businesses (of all sizes) to communicate effectively. It's organized, easily accessible, and more important, it allows for better and more efficient communication than email. Slack isn't limited to just professional use; it also can be adopted for more personal uses.

The Interview

Petros Koutoupis: Why snap?

This year was a big one for companies like Canonical and Slack. It also was a big year for technologies that Canonical created to enable third-party application support—specifically, the snap package.

I'm sure most, if not all, of you have heard about this package manager. In fact, it's been around since at least 2014, but it initially was developed around Canonical's Ubuntu phone operating system. Now, although the phone operating system has since been canceled, snaps continue to dominate the operating system, in both the server and desktop space.

What Is a Snap?

A "snap" application package is a self-contained piece of software, and although it originally was designed to be hosted on Ubuntu, the package will work across a range of other Linux distributions. This isn't your traditional APT or YUM manager hosting DEB and RPM (or other) package formats.

Again, the appeal to snap packages is that they are self-contained (that is, containerized). They are designed to auto-update and are safe to run. A snap package is bundled with its dependencies, which is what allows it to run on all other major Linux distribution without any modification. It also doesn't have any dependency to any package manager or application store. But, don't misunderstand this—a package manager or application store still can host one or more snap packages; however, the snap package is not dependent to that manager.

Snapcraft is the official tool for software developers to package their software programs in a Snap format.

Sitting Down with Canonical and Slack

Earlier this year on January 18th, Canonical announced the first iteration of Slack as a snap. But, why was this announcement so important? I recently had the pleasure of sitting down with Evan Dandrea of Canonical and Felix Riesberg of Slack. They gave me the answers I was looking for.

Evan's team at Canonical builds the platform to make everyone's life easier—that is, Snapcraft. And Felix's team leverages that very same platform to bring wonderful applications, such as Slack, to your Linux desktop.

First, for those not familiar with Slack, it's an enterprise software platform that allows teams and businesses (of all sizes) to communicate effectively. It's organized, easily accessible, and more important, it allows for better and more efficient communication than email. Slack isn't limited to just professional use; it also can be adopted for more personal uses.

The Interview

Petros Koutoupis: Why snap?

I heard that Microsoft would be buying GitHub just a couple days before it happened when Carlie Fairchild at Linux Journal told me about it. I replied to the news with a solid, “Get! Out!” Needless to say, I had my doubts. As someone who remembers all too well the “Embrace, extend and extinguish" days of Microsoft, the news of this latest embrace did, however briefly, bring back those old memories. When I was asked what I thought, I answered that the optics were bad.A lot of years have passed since, back in 2001, Steve Ballmer declared Linux to be a cancer. These days, Microsoft loves Linux. It says so right on its website. Two years ago, Steve Ballmer also proclaimed his love for Linux. In 2018, Microsoft has its own distribution that it uses in its Azure cloud. Microsoft includes several different flavors of Linux in its app store (the Windows Subsystem for Linux), all of which can be installed on Windows 10. Microsoft develops for Linux. Heck, Microsoft even contributes to the Linux kernel.

The reason I felt the optics were bad is that Microsoft has spent the last few years going out of its way to paint itself as a friend to Linux and open source. This, I thought, can only be seen as a bad move. Well, it’s been three weeks, more or less, since the the acquisition became official, to the tune of $7.5 billion US. What happened?

For starters, Jim Zemlin, the Executive Director of the Linux Foundation, praised the Microsoft acquisition of GifHub, suggesting that it could be a good thing for everyone. Former open-source star and the new CEO of GitHub, Nat Friedman, did an AMA on Reddit to reassure developers of open-source software that they had nothing to fear from the new landlords.

Linus Torvalds, the creator of the Linux kernel and git itself, didn’t comment directly, but he has been critical of GitHub in the past, so perhaps it doesn’t change anything for him. Besides, the kernel is primarily housed on a private git server, and GitHub is just a public mirror for the code.

That didn’t stop some number of open-source developers from swearing off GitHub and looking for other places to host their projects. GitLab, a minor competitor to GitHub, seemed poised to be the natural beneficiary of this move. In a Twitter post dated June 3rd, it cited that its GitHub to GitLab conversion rate was running at ten times normal.

I heard that Microsoft would be buying GitHub just a couple days before it happened when Carlie Fairchild at Linux Journal told me about it. I replied to the news with a solid, “Get! Out!” Needless to say, I had my doubts. As someone who remembers all too well the “Embrace, extend and extinguish" days of Microsoft, the news of this latest embrace did, however briefly, bring back those old memories. When I was asked what I thought, I answered that the optics were bad.A lot of years have passed since, back in 2001, Steve Ballmer declared Linux to be a cancer. These days, Microsoft loves Linux. It says so right on its website. Two years ago, Steve Ballmer also proclaimed his love for Linux. In 2018, Microsoft has its own distribution that it uses in its Azure cloud. Microsoft includes several different flavors of Linux in its app store (the Windows Subsystem for Linux), all of which can be installed on Windows 10. Microsoft develops for Linux. Heck, Microsoft even contributes to the Linux kernel.

The reason I felt the optics were bad is that Microsoft has spent the last few years going out of its way to paint itself as a friend to Linux and open source. This, I thought, can only be seen as a bad move. Well, it’s been three weeks, more or less, since the the acquisition became official, to the tune of $7.5 billion US. What happened?

For starters, Jim Zemlin, the Executive Director of the Linux Foundation, praised the Microsoft acquisition of GifHub, suggesting that it could be a good thing for everyone. Former open-source star and the new CEO of GitHub, Nat Friedman, did an AMA on Reddit to reassure developers of open-source software that they had nothing to fear from the new landlords.

Linus Torvalds, the creator of the Linux kernel and git itself, didn’t comment directly, but he has been critical of GitHub in the past, so perhaps it doesn’t change anything for him. Besides, the kernel is primarily housed on a private git server, and GitHub is just a public mirror for the code.

That didn’t stop some number of open-source developers from swearing off GitHub and looking for other places to host their projects. GitLab, a minor competitor to GitHub, seemed poised to be the natural beneficiary of this move. In a Twitter post dated June 3rd, it cited that its GitHub to GitLab conversion rate was running at ten times normal.

Apple, Google and Amazon are taking voice control to the next level. But can voice control be a DIY project? Turns out, it can. And, it isn't as hard as you might think.

Siri, Alexa and Google Home can all translate voice commands into basic activities, especially if those activities involve nothing more than sharing digital files like music and movies. Integration with home automation is also possible, though perhaps not as simply as users might desire—at least, not yet.

Still, the idea of converting voice commands into actions is intriguing to the maker world. The offerings from the big three seem like magic in a box, but we all know it's just software and hardware. No magic here. If that's the case, one might ask how anyone could build magic boxes?

It turns out that, using only one online API and a number of freely available libraries, the process is not as complex as it might seem. This article covers the Jarvis project, a Java application for capturing audio, translating to text, extracting and executing commands and vocally responding to the user. It also explores the programming issues related to integrating these components for programmed results. That means there is no machine learning or neural networks involved. The end goal is to have a selection of key words cause a specific method to be called to perform an action.

APIs and Messaging

Jarvis started life several years ago as an experiment to see if voice control was possible in a DIY project. The first step was to determine what open-source support already existed. A couple weeks of research uncovered a number of possible projects in a variety of languages. This research is documented in a text document included in the docs/notes.txt file in the source repository. The final choice of a programming language was based on the selection of both a speech-to-text API and a natural language processor library.

Since Jarvis was experimental (it has since graduated to a tool in the IronMan project), it started with a requirement that it be as easy as possible to get working. Audio acquisition in Java is very straightforward and a bit simpler to use than in C or other languages. More important, once audio is collected, an API for converting it to text would be needed. The easiest API found for this was Google's Cloud Speech REST API. Since both audio collection and REST interfaces are fairly easy to handle in Java, it seemed that would be the likely choice of programming language for the project.

Linux Journal's FOSS Project Spotlights provide an opportunity for free and open-source project team members to show Linux Journal readers what makes their project compelling. Join us this weekend as we explore some of the latest FOSS projects in the works.

FOSS Project Spotlight: Mender.io, an Open-Source Over-the-Air Software Update Manager for IoT Devices

by Ralph Nguyen

Mender is an open-source (Apache 2.0) project to address over-the-air (OTA) software update management for Linux-based IoT devices.

FOSS Project Spotlight: Nitrux, a Linux Distribution with a Focus on AppImages and Atomic Upgrades

by Nitrux Latinoamericana S.C.

Nitrux is a Linux distribution with a focus on portable, application formats like AppImages. Nitrux uses KDE Plasma 5 and KDE Applications, and it also uses our in-house software suite Nomad Desktop.

FOSS Project Spotlight: Tutanota, the First Encrypted Email Service with an App on F-Droid

by Matthias Pfau

Seven years ago, Tutanota was being built, an encrypted email service with a strong focus on security, privacy and open source. Long before the Snowden revelations, the Tutanota team felt there was a need for easy-to-use encryption that would allow everyone to communicate online without being snooped upon.

FOSS Project Spotlight: LinuxBoot

by David Hendricks

Linux as firmware.

The more things change, the more they stay the same. That may sound cliché, but it's still as true for the firmware that boots your operating system as it was in 2001 when Linux Journal first published Eric Biederman's "About LinuxBIOS". LinuxBoot is the latest incarnation of an idea that has persisted for around two decades now: use Linux as your bootstrap.

FOSS Project Spotlight: CloudMapper, an AWS Visualization Tool

by Scott Piper

Duo Security has released CloudMapper, an open-source tool for visualizing Amazon Web Services (AWS) cloud environments.

I've been covering chemistry software in my last few articles, so this time, I decided to move to physics and introduce a package called JaxoDraw. In physics, there's a powerful technique for visualizing particle interactions at the quantum level. This technique uses something called Feynman diagrams, invented by physicist Richard Feynman. These diagrams help visualize what happens when one or more particles have some kind of interaction. I say one or more because a single particle could spontaneously kick out other particle/anti-particle pairs and then swallow them back up again. Needless to say, quantum physics is weird.

When first developed, theoretical physics was mostly done either with pen and paper or on a chalkboard. Not much thought was given as to how you could render these drawings within a document being written on a computer. JaxoDraw is meant to help fill in that gap in document layout and provide the ability to render these drawings correctly and give output you can use in your own documents.

JaxoDraw is written in Java, so it should run under almost any operating system. Unfortunately, it isn't likely to be in the package repository for most distributions, so you'll need to download it from the project's website. But, because it's packaged as a jar file, it's relatively easy to run.

Download the binary package, unpack it on your machine, and then you'll want to open a terminal and change directory to the location where you unpacked JaxoDraw. You can start it simply by typing the following:

java -jar jaxodraw-2.1.0.jar

This opens a blank workspace where you can start your diagram. On the left-hand side of the window, you'll see a palette of all of the available drawing elements that you can use to generate your diagram.

Figure 1. When you first open JaxoDraw, you see a blank workspace where you can start diagramming your quantum particle interaction.

To see what's involved, let's draw an electron interacting with a photon. This happens when energy is absorbed or emitted by an electron. Since you're looking at an interaction, you'll want to start by selecting the vertex button from the palette and then draw one in the window. Coming into this vertex will be a fermion line for the electron and a photon line for the incoming electromagnetic energy. The interaction happens at the vertex, with a second fermion line coming out the other end. You can continue adding more elements, including loops or bezier lines, and you also have the choice of other particle types, such as scalar particles, ghost particles or gluons.