[md] vbetool is a utility for executing real-mode x86 BIOS calls, commonly used for power management and display mode switching on legacy systems. Rocky Linux 9 doesn’t include it in standard repositories, so you’ll need to build it from source. ## What vbetool Does vbetool communicates with the video BIOS through the Video BIOS Extensions…
RPM Fusion provides packages that Fedora and RHEL can’t ship by default due to patent, licensing, or trademark restrictions. This includes multimedia codecs, proprietary drivers, and other software. Here’s how to enable it on RHEL 9 and Rocky Linux. Enable RPM Fusion Free and Non-Free # Enable EPEL first (required dependency) sudo dnf install epel-release…
Fedora’s default repositories don’t include musl libc, but you have two practical options: install it from a community repository if available, or build from source. Building from source gives you full control and is the most reliable approach across Fedora versions. Option 1: Build from Source (Recommended) Start by installing the build dependencies: sudo dnf…
Converting PPTX presentations to image files on Linux requires a two-step process: first convert to PDF, then rasterize to your target image format. This approach preserves slide layout and fonts better than direct conversion tools. Convert PPTX to PDF Start by converting your PowerPoint file to PDF using LibreOffice: libreoffice –headless –convert-to pdf presentation.pptx The…
MPlayer has been largely superseded by mpv in most Linux distributions, but if you need the classic MPlayer with DVD navigation support, building from source remains the way to get libdvdnav integrated. Most distribution packages omit this feature due to licensing complexity. Prerequisites You’ll need a C compiler, build tools, and development libraries. On Fedora/RHEL-based…
Distributed systems need consensus — a way for multiple nodes to agree on state despite failures and network partitions. Understanding the key algorithms behind consensus is essential for anyone designing reliable systems. Paxos and Its Variants Paxos is the foundational consensus algorithm, proven to tolerate Byzantine failures. It works in three phases: prepare, accept, and…
Deleted photos from your Samsung phone aren’t necessarily gone forever—they remain on disk until overwritten. Here’s how to recover them. Act quickly to preserve data The moment you realize photos are deleted, stop using your phone. Every new photo, message, or app activity risks overwriting deleted data. Turn off WiFi and mobile data to prevent…
When should the authors anonymize themselves in a paper submitted to a conference for review? Several general concepts: Peer review is the evaluation of work by one or more people of similar competence to the producers of the work (peers). — Wikipedia Single-blind describes experiments where information that could introduce bias or otherwise skew the…
Measuring the execution time of a function is useful for profiling and optimization work. OCaml provides straightforward tools for this. Basic approach with Unix.gettimeofday The simplest method uses Unix.gettimeofday(), which returns wall-clock time as a float with microsecond precision: let time f = let t = Unix.gettimeofday () in let res = f () in…
LXTerminal may fail to display Chinese characters correctly if fonts aren’t properly configured. This is typically a font availability or configuration issue rather than a terminal limitation. Check Your Font Setup First, verify that Chinese fonts are installed on your system. Install them if needed: Fedora/RHEL: sudo dnf install fonts-noto-cjk Debian/Ubuntu: sudo apt install fonts-noto-cjk…
Filtering RSS feeds lets you reduce noise and focus on content that actually matters. Whether you want to exclude posts mentioning certain topics or only see items matching specific keywords, there are several practical approaches depending on your setup. Using dedicated feed filtering services Feed43 (https://www.feed43.com/) is one of the most reliable web-based tools for…
Logging connections that hit rate-limit rules helps you identify brute force attempts and troubleshoot legitimate clients that are being blocked. The standard approach is to create a dedicated chain that logs packets before dropping them. Create a logging and drop chain First, create a custom chain to handle logging and dropping: iptables -N LOGNDROP iptables…
Listing active services is essential for system monitoring and troubleshooting. Whether you’re investigating a hung process, checking if a daemon started correctly, or auditing what’s actually running on your system, knowing how to query service status quickly saves time. Basic Command The standard way to list running services across all modern Linux distributions is: systemctl…
iptables remains the standard firewall configuration tool on Linux systems, though many distributions now layer it with ufw or firewalld. Understanding the basics helps you troubleshoot, migrate, or work on systems without those abstractions. Understanding iptables Fundamentals iptables operates on three main chains: INPUT: rules for incoming traffic FORWARD: rules for traffic passing through the…
Making firewall rules persistent across system reboots is essential for any production Linux system. While the original iptables-persistent approach works, modern systems typically use ufw (Uncomplicated Firewall) or firewalld, but understanding the underlying iptables mechanism is still valuable for lower-level control. Using iptables-persistent The iptables-persistent package automatically saves and restores your firewall rules during boot….
Rate-limiting SSH brute-force attempts is essential for any server exposed to the internet. Using iptables with the recent module, you can drop connections from IPs that exceed a threshold in a given time window—for example, blocking IPs that attempt more than 6 connections in 60 seconds. Using iptables The recent module tracks connection attempts by…
ELPA (Emacs Lisp Package Archive) packages receive regular updates. Keeping your packages current ensures you have the latest features and bug fixes. Here’s how to upgrade ELPA packages in Emacs. Interactive Upgrade (Recommended) Use Emacs’s built-in package manager: Open the package list: M-x list-packages Press U to mark all upgradable packages Press x to execute…
Xterm doesn’t send Alt key escape sequences by default, which breaks Alt-based keybindings in Vim, Emacs, shell readline, and other applications. Here’s how to fix it across different terminal setups. Xterm Configuration Add this to your ~/.Xresources file: xterm*metaSendsEscape: true Then load the changes and restart xterm: xrdb -merge ~/.Xresources xterm & This tells xterm…
When managing packages on Ubuntu or Debian systems, knowing what versions are available—and which one will be installed—is essential for dependency management and system stability. The aptitude command provides several ways to inspect package versions. Check all available versions of a package The most straightforward approach is to use the versions subcommand: aptitude versions package-name…
musl libc is a lightweight C library implementation that’s useful for creating statically-linked binaries, containerized applications, and embedded systems. It’s the standard C library in Alpine Linux and increasingly common in production environments. Installation from distribution repositories The simplest approach is installing musl from your distribution’s repositories: sudo apt update sudo apt install musl musl-dev…