Linux MagazineJuly 2020的目錄

Dear Reader, Walmart purchased Jet.com in 2016 with the usual fanfare that comes from a $3.3 billion corporate purchase. Jet.com was an up-and-coming online company, only a year old, that was trying to get an edge on the retail market by offering an innovative discount system and improving the distribution chain. These billion-dollar assimilations happen all the time in the high-tech industry. The most common scenario is a big high-tech company like Facebook or Amazon buying a startup, but another scenario that is also churning out there in the IT space is the phenomenon of old-school brick-and-mortar companies buying online startups in order to gain a foothold on the future and inject some high-tech juju into their doddering corporate culture. The Jet.com purchase was widely seen as Walmart’s effort to…

Right on schedule, Canonical has released the latest version of the Ubuntu. Ubuntu 20.04 “Focal Fossa” includes plenty of new features that should excite any and all Linux and Ubuntu fans. This latest iteration is an Long Term Support (LTS) release, which means it will be supported until 2025. Focal Fossa is built upon the Linux 5.4 kernel (which is also an LTS release). One of the most anticipated features included with 20.04 is the WireGuard VPN service, which is built in at the kernel level and is significantly easier to set up than a traditional VPN. WireGuard is also more secure than other solutions, partially because it is implemented within the kernel and is limited to using only new and more secure cryptographic protocols. Another big addition to Ubuntu…

LAMP (Linux, Apache, MySQL, PHP/Perl/Python) servers are common service stacks for hosting applications such as Open-Cart. In this example, I am using MariaDB, a drop-in replacement for MySQL. Assuming a Devuan environment, the following command will install the necessary components for a LAMP server: Since you will be hosting a store, TLS encryption is required to ensure secure communication between the server and the customers. The following commands will enable TLS: If Apache does not create a certificate automatically in your distribution, you will have to create it manually [4]. Self-signed certificates are not suitable for production, but they are fine for testing. If you intend to move this server to production, you will need to purchase a certificate from a certificate authority and install it [5]. Alternatively, you can…

Inspired by an earlier article in Linux Pro Magazine [1], I had been thinking for some time about the idea of using a computer to measure the moisture of three potted plants in my office and watering them automatically when needed. When I came across an inexpensive kit with sensors and pumps, the time had come to tackle the subject. The first idea for watering the three flower pots was to use a pump with a valve system to regulate which pot was watered. However, online research did not reveal any low-cost systems, so the project ended up back in the drawer. A later search took me to an irrigation kit by the Chinese company WayinTop that contains four individual pumps, four humidity sensors, a relay module, and a matching…

The prejudice that guitarists can’t read music is as persistent as the assumption that bassists don’t have a girlfriend. And there is some evidence to support the former – at least when you think about campfire songsters and shopping mall bards. But even these string instrumentalists can’t manage without at least some notation and music theory. They add standardized chord names to their lyrics and can then read and accompany known songs without any problems. To do this, you simply enter the chord abbreviations in every second line above the word where the fingering changes (Listing 1). Now imagine that you’re making the move from handwritten notation to a word processor. This can work quite well as long as you use a monospace font. The problem is that with proportional…

Sparkling gems and new releases from the world of Free and Open Source Software Vector editor Inkscape 1.0 There can’t be many Linux users who don’t know about Inkscape or who haven’t at least used it to knock out a birthday card, ad-hoc poster, or logo. It’s one of the hallmarks of open source software and a genuine competitor to expensive, often subscriptionbased, products like Adobe Illustrator. But what’s most remarkable about Inkscape is that, despite its vintage (the project is two decades old, forking from Sodipodi in 2004), it has never taken that final step to credibility – a 1.0 release. For the entire duration of the project, while it implemented vector-based drawing, transformations, calligraphy, pencil tools, bitmap tracing, Boolean operations, antialiased output, hardware acceleration, and countless other features,…

Order online: https://bit.ly/Linux-Newsstand What’s New in Systemd Systemd is a mystery that keeps on giving. Now a new feature of the leading Linux init system will change the way you think about user home directories. This month we take a closer look at systemd-homed. On the DVD: Knoppix 8.6.1 and OpenMandriva Lx Plasma 4.1 Edge Computing The Edge is a popular buzz word in high-tech news, but what does it mean really? We introduce you to an exciting new technology that could be changing the way we think about the cloud. On the DVD: Manjaro 19.02 Gnome Edition and SystemRescueCd 6.1 Stream to Your TV The line between computers and television blurred long ago, but the new tools and new ideas keep coming. This month we highlight some innovative apps…

If you’re a Linux admin, chances are you either program yourself or you work with programmers who help to make your job easier. With that in mind, Git is probably on the forefront of your work environment. To that end, you’ll be happy to know the latest release of the open source version control system includes some exciting new features. Standing on top of that feature list is that Git protocol version 2 has now become the default for Git. This is important because the original protocol wasn’t nearly efficient enough for large projects. With version 1, the Git server would list all branches, tags, and other repository references before a client could send anything. If a repository was large, megabytes of information had to be sent, even if only…

A network diagram [2] is the visual representation of all the elements that compose a network and how the elements are connected. In project management, a network diagram describes all of a project’s activities, their dependencies, and the corresponding workflow, from beginning to end. Other information includes costs, risks, and responsibilities for each task. When done properly, network diagrams make it easier to make good decisions – and also to document why a decision is good. Historically, there have been two main methods, often mixed together, for using network diagrams in project management: the arrow diagramming method (ADM) and the precedence diagramming method (PDM). ADM shows events as nodes and activities as arrows. In PDM, activities are boxes that contain several parameters, and the arrows that connect the boxes represent…

So many formats! Users pass around word-processing documents, spreadsheets, videos, digital photos, PDFs, and a myriad of other objects, each with a specialized format tailored to the purpose. With all the sophisticated formats in circulation today, it is worthwhile to pause and consider the power of the simple text file. An HTML file is a text file. Text files are light and easy to store and send. The humble text file is also universally understood by different operating systems – and a great many different human languages. What else can you do with a text file? This month we look at ChordPro, a text format for displaying song chords and lyrics. Just as the Internet makes it easy to listen to songs, it also makes it very easy to play…

Linux Usage Is on the Rise The COVID-19 pandemic has had some severe effects on the economy and consumer spending habits. Businesses have shuttered, unsure if they’ll survive the months-long closure. And although it’s hard to find a silver lining in all the market data, one positive outcome is that the Linux operating system has witnessed a large surge in usage. Before you get too excited, it’s not as though Linux all of a sudden surged past either Windows or macOS. In fact, Linux desktop usage is still in the single digits. However, in comparison, Linux actually bested both Windows and macOS for growth in April. The numbers paint an interesting picture, one that points directly to Ubuntu. During the month of April, Ubuntu gained 1.61 percent (from 0.27 percent…

Linux Magazine www.linux-magazine.com ADMIN HPC http://www.admin-magazine.com/HPC/ Tips and Tricks for Containers • Jeff Layton Various aspects of containers make them more useful to you. Pymp – OpenMP-like Python Programming • Jeff Layton Ever since Python was created, users have been looking for ways to achieve multiprocessing with threads, which the Python global interpreter lock (GIL) prevents. ADMIN Online http://www.admin-magazine.com/ Serverless run times with custom Bash AWS Lambda layers • Chris Binnie A piece of old-meets-new functionality lets you run Bash scripts in an AWS Lambda layer. Cloud-native application bundles for easy container deployment • Martin Loschwitz Cloud-native application bundles are an easy option for distributing applications in a microservice architecture. Use PowerShell to manage Exchange Online • Thomas Joos Exchange Online in Office 365 can be managed just like its local counterpart with…

Author The Linux kernel mailing list comprises the core of Linux development activities. Traffic volumes are immense, often reaching 10,000 messages in a week, and keeping up to date with the entire scope of development is a virtually impossible task for one person. One of the few brave souls to take on this task is Zack Brown. Adapting to COVID-19 The ongoing COVID-19 pandemic does not seem to have slowed Linux kernel development, although in-person gatherings are being abandoned in favor of online alternatives. For example, Josef Bacik announced in late April that the Linux Storage, Filesystem, and Memory Management Summit would be canceled this year. He added, “Next year the summit will be held in Palm Springs, on May 12-14, 2021 at the Riviera Palm Springs. A new CFP…

The TechLead [1], Patrick Shyu, is a YouTube celebrity whose videos I like to watch. The former Google employee, who has also completed a gig at Facebook, talks about his experiences as a software engineer in Silicon Valley in numerous episodes on his channel (Figure 1). His trademark is to hold a cup of coffee in his hand and sip it pleasurably every now and then while he repeatedly emphasizes that he’s the “tech lead.” That’s how Google refers to lead engineers who set the direction for the other engineers on the team. The first-line managers there traditionally stay out of technical matters and focus primarily on staffing and motivating their reports. One episode on the TechLead channel is about typical questions asked at interviews at Google, of which the…

Debian was one of the first distributions to have a modern package system. Over the decades, a whole ecosystem of related commands has grown up around it, including front ends like apt-get and, more recently, apt for the basic package manager dpkg, and then utilities ranging from apt-file for searching files inside packages to apt-cache for searching packages. In fact, a search on “apt” in the Stable repository for Debian 10 returns 54 hits, while a search on “deb” returns 68. One of the lesser-known but handier members of this ecosystem is debfoster [1], whose main purpose is to weed out unnecessary packages. However, like apt, debfoster actually combines several other functions, displaying information on currently installed packages, and serving as a replacement for apt-get. You can start to use…

Linux on Laptops It was recently announced that Fedora was going to be supported on Lenovo laptops [1]. Some GNU/Linux people complained that it was Fedora. Some people complained that Lenovos were “expensive.” Some people complained that there might be “bloat-ware.” Some people just complained. No wonder some manufacturers and store owners hate free software people! I have more than a few deep scars from 50 years in the computer industry. I am about to teach you several lessons. Don’t bother arguing with me … I am right … you will lose. First lesson: Computer stores do not sell computers. Just as grocery stores do not sell groceries. They sell shelf space. The faster the items fly off the shelf, the more profit the stores make. Yes, they have low-priced…

No other operating system offers such a multitude of desktop environments as Linux. However, many of these user interfaces are very similar: MATE, Xfce, LXDE, and Trinity are based on similar ideas; their differences relate more to appearance and (under the hood) resource requirements. Resource-friendly work environments, on the other hand, often deviate so greatly from modern approaches that they require a longer period of acclimatization. In addition, they often appear visually antiquated. Enter theShell [1]. If you are thinking it is just a lean desktop, you may be surprised that it does many things differently. Based on the Qt toolkit, theShell works with the KDE KWin window manager by default. You can find theShell’s source code [2] on GitHub, which means that you can compile it on any distribution.…

If you are looking to keep track of your finances, improve your financial planning, and discover potential savings, it’s essential to accurately track your assets and expenses. KMy-Money [1], a KDE financial management program, is designed to make this process easier. While it is primarily aimed at individuals tracking their personal finances, it may also be useful for some smaller commercial enterprises and associations. As of this writing, the latest version of KMy-Money is 5.0.7. It runs not just on KDE Plasma, but also on Gnome (e.g., on Ubuntu). The program sources are available for download from the KDE website. The commands from Listing 1 allow you to install KMyMoney below/opt/in a terminal window. This relies on CMake [2], which most popular distributions preinstall, but you may need to install…

For other events near you, check our extensive events calendar online at http://linux-magazine.com/events. If you know of another Linux event you would like us to add to our calendar, please send a message with all the details to events@linux-magazine.com. NOTICE Be sure to check the event website before booking any travel, as many events are being canceled or converted to virtual events due to the effects of COVID-19. Xen Developer & Design Summit Date: July 6–9, 2020 Location: Virtual Event Website:https://events.linuxfoundation.org/xen-summit/ The Xen Project Developer and Design Summit brings together the Xen Project’s community of developers and power users for their annual developer conference. Share ideas, the latest developments, and have fun meeting the community that defines the Xen Project. Attend presentations with live Q&A, Design Sessions, and much more!…

We are always looking for good articles on Linux and the tools of the Linux environment. Although we will consider any topic, the following themes are of special interest: • System administration• Useful tips and tools• Security, both news and techniques• Product reviews, especially from real-world experience• Community news and projects If you have an idea, send a proposal with an outline, an estimate of the length, a description of your background, and contact information to edit@ linux-magazine.com. The technical level of the article should be consistent with what you normally read in Linux Magazine. Remember that Linux Magazine is read in many countries, and your article may be translated into one of our sister publications. Therefore, it is best to avoid using slang and idioms that might not be…

Preview Newsletter The Linux Magazine Preview is a monthly email newsletter that gives you a sneak peek at the next issue, including links to articles posted online. Sign up at: https://bit.ly/Linux-Update Approximate UK / Europe JUl 04 USA / Canada Jul 31 Australia Aug 31 On Sale Date…