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Programming Leftovers and HowTos

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  • Color Maps and Conditional Formatting

    When visualizing the data, mapping of values to colors is one of essential steps. There is an extensive discussion in the literature about the proper selection of colors (see e.g. the publications mentioned here), and there are multiple publicly available collections of color maps that are designed to deliver best results in scientific visualization applications. For the coming release 2.9 we added some of the well-known collections to LabPlot.

  • Pete Zaitcev: Swift in 2021

    A developer meet-up for OpenStack, known as PTG, occurred a week ago. I attended the Swift track, where somewhat to my surprise we had two new contributors show up.

    I got into a habit of telling people that I did not want Swift to end like AFS: develop great software and dead, with nobody using it. Today I looked it up, and what do you know: OpenAFS made a release in June 2020 (and apparently they also screwed up and had to post an emergency release in October).

  • Discover Bottlenecks on QNX

    QNX is commonly the operating system of choice, when it comes to developing on embedded systems. However, the performance limits are exceeded quickly, especially if you’re working on low-end hardware. As a result, you’ll likely need to perform an investigation to find the bottlenecks that contribute to reaching these limits, in order to configure your application to fit the requirements of your system.

    There are many reasons why an application might be slow. Any number of bottlenecks could be causing the delays. In our experience, file reads and writes have been relevant factors, due to bandwidth limitations.

  • Network, learn and get inspired together - DEV/DES DAYS 2021

    The last year has been a roller coaster! As everything continues to be virtual, we wanted to create something special to bring people together and escape the reality.


  • Rustup 1.24.0 release incident report for 2021-04-27

    On 2021-04-27 at 15:09 UTC we released a new version of Rustup (1.24.0). At 15:23 UTC we received a report that we had introduced a regression in the part of the code which is responsible for proxying the rustfmt and cargo-fmt portions of Rust toolchains. At 15:27 UTC we had confirmed and identified the cause of the problem, and while we worked on a fix, we reverted the released Rustup to version 1.23.1 - an action completed by 15:56 UTC.

    This means that for approximately 47 minutes, CI jobs which used the code formatting features of Rust toolchains may have had spurious failures, and users who upgraded will have had to revert to 1.23.1. The revert process is designed to be as easy as upgrading was, meaning that users should not have had lingering issues.

  • Automatic load balancing for PMD threads in Open vSwitch with DPDK - Red Hat Developer

    This article is about the poll mode driver (PMD) automatic load balance feature in Open vSwitch with a Data Plane Development Kit data path (OVS-DPDK). The feature has existed for a while but we’ve recently added new user parameters in Open vSwitch 2.15. Now is a good time to take a look at this feature in OVS-DPDK.

    When you are finished reading this article, you will understand the problem the PMD auto load balance feature addresses and the user parameters required to operate it. Then, you can try it out for yourself.

  • Enhance application security by rotating 3scale access tokens

    In Red Hat 3scale API Management, access tokens allow authentication against the 3scale APIs. An access token can provide read and write access to the Billing, Account Management, and Analytics APIs. Therefore, ensuring you are handling access tokens carefully is paramount.

    This article explains how to enhance security by making access tokens ephemeral. By the end of the article, you will be able to set up 3scale to perform access token rotation. An external webhook listener service performs the actual token revocation. The rotation takes place automatically after a specific event triggers a webhook.

  • KDE Activities: How To
  • Everything You Need to Know About IP Addresses on Ubuntu

    Don’t know how to find your system's IP address in Ubuntu? No problem. In this guide, we’ve covered everything related to IP addresses in Ubuntu for you. Apart from learning about IP addresses, we'll also discuss how to find your system IP address along with a guide on setting a static IP address in Ubuntu.

More in Tux Machines

Kernel: Graphics and Linux M1 Support

  • AMD + Valve Focusing On P-State / CPPC Driver With Schedutil For Better Linux Efficiency - Phoronix

    As reported at the start of August, AMD and Valve have been working on Linux CPU performance/frequency scaling improvements with the Steam Deck being one of the leading motivators. As speculated at that time, their work would likely revolve around use of ACPI CPPC found with Zen 2 CPUs and newer. Published last week was that AMD P-State driver for Linux systems indeed now leveraging CPPC information. AMD formally presented this new driver yesterday at XDC2021.

  • DRM Driver Posted For AI Processing Unit - Initially Focused On Mediatek SoCs - Phoronix

    BayLibre developer Alexandre Bailon has posted a "request for comments" of a new open-source Direct Rendering Manager (DRM) driver for AI Processing Unit (APU) functionality. Initially the driver is catering to Mediatek SoCs with an AI co-processor but this DRM "APU" driver could be adapted to other hardware too. Alexandre Bailon sums up this DRM AI Processing Unit driver as "a DRM driver that implements communication between the CPU and an APU. This uses VirtIO buffer to exchange messages. For the data, we allocate a GEM object and map it using IOMMU to make it available to the APU. The driver is relatively generic, and should work with any SoC implementing hardware accelerator for AI if they use support remoteproc and VirtIO."

  • Apple M1 USB Type-C Linux Support Code Sent Out For Testing - Phoronix

    he latest patches sent out for review/testing on the long mission for enabling Apple M1 support on Linux is the USB Type-C connectivity. Sven Peter has sent out the initial USB Type-C enablement work for the Apple ACE1/2 chips used by Apple M1 systems. In turn this Apple design is based on the TI TPS6598x IP but various differences. The Linux kernel support is being added onto the existing TIPD driver.

Proprietary Security Issues

Audiocasts/Videos: GNU World Order, Sioyek, LUTs

today's howtos

  • How to Install VirtualBox on Debian 11 (Bullseye)

    As we all know that VirtualBox is a free virtualization tool which allows us to install and run multiple virtual machines of different distributions at the same time. VirtualBox is generally used at desktop level where geeks used to create test environment inside the virtual machines. Recently Debian 11 (bullseye) is released with latest updates and improved features. In this post, we will cover how to install VirtualBox and its extension pack on Debian 11 system.

  • How To Install Opera Browser on Debian 11 - idroot

    In this tutorial, we will show you how to install Opera Browser on Debian 11. For those of you who didn’t know, Opera is one of the most popular cross-platform web browsers in the world. Opera offers many useful features such as free VPN, AdBlocker, integrated messengers, and private mode help you browse securely and smoothly. Share files instantly between your desktop and mobile browsers and experience web 3.0 with a free crypto wallet. This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you through the step-by-step installation of Opera Web Browser on a Debian 11 (Bullseye).

  • Get your Own URL Shortening Service With YOURLS and Raspberry PI

    Online URL shortening are services able to transform a long, hard to manage url into a shorter one, usually composed by a domain ana a short casual string (the most famous being Bitly, Adfly and Shortest). With YOURLS and Raspberry PI you can create your own, private shortening service In this tutorial, I’m going to show you how to install and configure YOURLS with a Raspberry PI computer board and publish it. Please note that this can’t be performed with a Raspberry PI Pico as it is a microncotroller and not a Linux computer. YOURLS stands for Your Own URL Shortener. It is an open source software, running on a LAMP server and using a small set of PHP scripts that allow you to run your own URL shortening service.

  • How to play Orcs Must Die! 2 on linux

    Create your own, self hosted url shortener service with YOURLS and Raspberry PI. Step-by-step guide to have it working in a very few time

  • Configure External RAID on Ubuntu/Centos/RedHat - Unixcop

    RAID: Stands For Redundant Array Of Independent Disks (Hardware Raid) or Redundant Array Of Inexpensive Disks (Software Raid) and that is technology that keeps data redundant to avoid data loss if any disk falls or is corrupted .

  • Don’t like Visual Studio Code? Try these 5 Alternatives Apps - [Ed: Some of the 'alternatives' are also Microsoft and also proprietary software. Rather awful list...]

    When it comes to programming, we are going to need a plain text editor that allows us to easily modify files or take notes. One of the most complete and professional tools is Visual Studio Code. Although this Microsoft program is not indicated for users with little experience, so, if it is our case, surely we want to know what the best alternatives are. Anyone can download Virtual Studio Code, since it is completely free, but without a doubt, it has been designed to be used by programmers. In this field we find many other good options for professional work, especially if we are interested in knowing anything about a program developed by Microsoft.

  • How to Access BBSes in Linux Using Telnet

    In the '80s and early '90s, the most popular way to get online in the US was through Bulletin Board Systems or BBSes. While they're nowhere near as numerous as they were during their mid-90s heyday, there are still hobbyists operating these systems scattered around the world. And you can access them from Linux, without a dial-up modem.

  • How to solve the undefined variable/index/offset PHP error - Anto ./ Online

    This guide will you how to solve the notice undefined variable, index, or offset error that you are experiencing in PHP. This error is easy to spot in the warning and error message logs. Consequently, you will typically see a descriptive error message like this...