HTML entities represent characters that either have special meaning in HTML or benefit from explicit encoding. You have three syntax options: Named entity: &name; (e.g., ©) Decimal numeric: &#number; (e.g., ©) Hexadecimal numeric: &#xhexcode; (e.g., ©) With UTF-8 encoding (the only sensible choice in 2026), most special characters can be typed directly. However, certain characters…
Grab a release from kernel.org. Recent stable versions (6.x and later) are recommended for production systems: wget https://www.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.gz tar xf linux-6.12.tar.gz cd linux-6.12/ If wget isn’t available, use curl: curl -O https://www.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.gz Verify the tarball Always verify the kernel’s integrity using checksums and signatures published on kernel.org. This is essential for production systems: wget https://www.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.gz.asc…
Spring Shell is a framework for building command-line interfaces (CLIs) in Java applications. It provides structured command definition, argument parsing, tab completion, and history management—all integrated with the Spring ecosystem. Requirements and Setup Spring Shell 3.2+ requires Java 17+ and Spring Boot 3.2+. If you’re still on older versions, Spring Shell 2.x supports Java 8…
Flash is dead on the web. Adobe ended support on December 31, 2020, and all modern browsers removed plugin support years ago. If you need to view Flash content in 2026, you have two practical options: the Ruffle emulator or running legacy applications in isolated environments. Why Fresh Player Plugin and PPAPI Don’t Work Anymore…
Watching for filesystem changes and triggering actions is essential for development workflows—recompiling after source edits, restarting services when configs update, or running tests during coding. Linux’s inotify subsystem provides kernel-level file monitoring, and inotifywait makes it accessible from the command line. Installation Install inotify-tools on your system: Fedora/RHEL/CentOS: sudo dnf install inotify-tools Debian/Ubuntu: sudo apt…
The traditional fork-exec pattern works, but it’s error-prone. posix_spawn() handles process creation in a single call with several advantages: Atomic operation: Spawn and exec happen atomically, eliminating race conditions between fork and exec No fork quirks: You don’t need conditional logic for parent vs. child code paths — exec happens immediately in the child Direct…
Sending email notifications when commits are pushed to a central Git repository helps teams stay coordinated and maintains audit trails. This is handled through Git hooks—scripts triggered by repository events. How Post-Receive Hooks Work When a client pushes to your Git server, the post-receive hook executes automatically. This hook lives at GIT_DIR/hooks/post-receive in your bare…
VNC provides graphical remote access to Linux servers. For security, tunnel VNC traffic through SSH rather than expose it directly to the network. This guide covers Windows client setup with SSH tunneling. Prerequisites Windows client: SSH client: Native OpenSSH (built into Windows 10/11) or PuTTY VNC viewer: RealVNC Viewer, TigerVNC Viewer, or TightVNC Viewer Linux…
UDP (User Datagram Protocol) defined in RFC 768 provides a lightweight alternative to TCP. Unlike TCP’s stream-oriented approach, UDP delivers discrete packets — each recvfrom() or recvmsg() call returns one complete datagram. The tradeoff is real: you gain speed and lower overhead, but lose automatic reliability guarantees. Your application must handle packet loss, reordering, and…
Every LaTeX document requires a basic framework. Here’s the minimum viable structure: \documentclass{article} \usepackage[utf-8]{inputenc} \title{My Document} \author{Author Name} \date{\today} \begin{document} \maketitle \section{Introduction} Your content here. \end{document} Common document classes: article — reports, papers, short documents report — longer documents with chapters book — book-length documents with front/back matter beamer — slide presentations letter — formal…
Make is a build automation tool that reads configuration files (makefiles) to compile programs and manage project workflows. It’s been a standard in Unix/Linux development for decades and remains essential for managing builds where dependencies matter. Make works by defining targets and their dependencies, then specifying commands to build each target. When you run make,…
When debugging and optimizing C/C++ programs, you need to see how the compiler translates your source code into assembly. A mixed source and assembly listing lets you trace exactly what machine instructions correspond to each line of your source. Using objdump (Recommended Modern Approach) The most straightforward method is to compile with debugging symbols and…
The diff utility generates unified diffs that show changes between file versions. Always use the -u flag to create unified diffs, which are the standard format for patches. For a single file: diff -u original.c new.c > fix.patch For an entire directory tree: diff -rupN original/ new/ > patchfile.patch The flags break down as: -r:…
Xen remains a production hypervisor used by AWS EC2, Citrix Hypervisor, and other cloud providers, though most general-purpose Linux distributions have shifted toward KVM as their default. If you’re working with Xen in production or developing drivers, understanding its source code layout is essential. Top-Level Directory Structure The Xen source repository (hosted on xenbits.xen.org) is…
Xen remains a production-grade hypervisor used in enterprise environments (AWS EC2, Citrix Hypervisor), though KVM has become the default for most Linux distributions. This guide covers building a stable Xen Dom0 on current Fedora releases using modern kernel sources. Hardware Considerations This guide assumes server-class hardware with: Intel or AMD processor with virtualization extensions (VT-x…
This post documents jailbreaking procedures for legacy iOS devices (iPod Touch, early iPhone) using Spirit—an untethered jailbreak tool from the late 2000s. Modern iOS devices (2010 and later) use entirely different security models and jailbreak methods. This information is preserved for historical reference only and has no practical application to current iOS versions. About Spirit…
Xen remains a production hypervisor for enterprise deployments (AWS EC2, Citrix Hypervisor), though KVM has become the default for most Linux distributions. If you’re deploying Xen in 2026, you’ll likely be working with recent stable releases rather than the legacy versions covered in older guides. This guide covers building a modern Xen Dom0 environment on…
MapReduce remains a foundational programming model for processing large-scale distributed datasets, though its role has evolved alongside modern data processing frameworks. Hadoop implementations and other MapReduce systems require objective performance evaluation to guide infrastructure decisions and optimization efforts. PUMA (Princeton University MapReduce Benchmark) is a comprehensive benchmark suite developed by Faraz Ahmad and colleagues to…
Archived Content (2010): This post describes a research project from 2010. The tools and versions mentioned (Hadoop 0.20, MapReduce Streaming) are historically significant but have been largely superseded by modern distributed build systems like Bazel Remote Execution and cloud-native CI/CD pipelines. mrcc – A Distributed C Compiler System on MapReduce Original Project Date: January 2010…