Programming languages and software development
Archiving or copying a 1TB sparse file containing only 32MB of actual data is impractical with naive approaches—you’ll waste time and I/O bandwidth copying zeros. The solution is using SEEK_HOLE and SEEK_DATA flags with lseek(), which allow tools to skip over hole regions entirely. How SEEK_HOLE and SEEK_DATA work The Linux kernel provides two additional…
If you suspect a disk has bad blocks, use the badblocks utility to scan for them. This tool probes a device (usually a disk partition) and reports which blocks are unreliable or unreadable. Basic Usage badblocks /dev/sda1 This scans /dev/sda1 from the first block to the last block on the device. Common Options -s: Show…
MATE is a continuation of GNOME 2, maintained by the MATE Desktop Environment project. It’s included in Fedora’s official repositories and is a supported desktop option. Install MATE Desktop MATE is available as a desktop environment group in Fedora 41’s repositories. Install the base desktop with: sudo dnf install @mate-desktop The @mate-desktop group installs the…
When you mmap() a range larger than your system’s total physical memory plus swap, the kernel normally reserves swap space to back the mapping. If that reservation would exceed available swap, mmap() fails with ENOMEM. The MAP_NORESERVE flag lets you bypass this reservation requirement. Understanding the Default Behavior By default, when you call mmap() with…
NFSv4 significantly simplifies network exposure compared to NFSv3. Where NFSv3 requires managing multiple dynamic ports (mountd, statd, lockd), NFSv4 uses only port 111 (rpcbind) and port 2049 (NFS). This makes firewall configuration and port forwarding straightforward. For production environments, consider implementing Kerberos authentication (krb5, krb5i, or krb5p) instead of relying solely on network-based access control….
When you need to display data on point-of-sale receipts that isn’t available in the standard receipt designer, you’ll need to create a custom field. This involves work in both Dynamics 365 (the backend) and the Retail SDK (the POS application layer). This walkthrough covers adding a custom field—using item barcodes as an example—though the pattern…
This post covers .NET Core 2.1, which released in May 2018. Some of the predicted features below didn’t materialize as described; we’ll clarify what actually landed versus what was speculated. What is .NET Core? .NET Core is Microsoft’s open-source, cross-platform runtime for building applications in C#, F#, and Visual Basic. Unlike the monolithic .NET Framework…
If you’re working on Windows but need to interact with Linux systems, you’ll need reliable remote access tools. SSH is the standard—it’s secure, scriptable, and works everywhere. Here’s what actually matters. SSH Clients Windows Terminal + OpenSSH is the baseline for Windows 11. It’s built-in, integrates native SSH without extra installation, and handles key authentication…
Hibernate Envers is a proven auditing framework that automatically tracks changes to JPA entities without cluttering your domain model with logging code. It stores historical data in separate audit tables and lets you query entity states at any point in time. Why Use Hibernate Envers Envers handles the mechanics of change tracking transparently: Audits all…
ASP.NET Core remains one of the most efficient frameworks for building scalable web applications. This guide walks through deploying an ASP.NET Core MVC application to Azure App Service using Visual Studio — the quickest path from local development to production. Prerequisites You’ll need: An active Azure subscription (free tier accounts work fine for testing) Visual…
Google’s search algorithms have become significantly more sophisticated. What passed for acceptable SEO a decade ago—keyword stuffing, aggressive link manipulation, deceptive tactics—now triggers manual penalties or algorithmic demotions. If you’re managing websites, understanding these mistakes can prevent serious ranking damage. Misusing nofollow Tags Many site owners incorrectly use rel=”nofollow” to hide pages from search results…
SEO is not quick. This is the reality that catches most people off guard. The internet has conditioned us to expect instant results — viral content, overnight success, algorithmic magic that transforms a website in weeks. None of that applies to SEO. Be direct about expectations: a newly published page typically needs 3-6 months to…
Call forwarding redirects incoming calls to another number when you’re unavailable or without coverage. It’s a carrier-level feature managed through iOS Settings, but actual support and behavior depend entirely on your carrier’s implementation. Enable call forwarding Open Settings → Phone Tap Call Forwarding Toggle the switch to On Enter the phone number where calls should…
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…
The HTML5 <canvas> element lets you draw graphics programmatically using JavaScript. Unlike static images or SVG, canvas renders raster (bitmap) graphics directly to a 2D or 3D surface, making it ideal for animations, games, real-time visualizations, and interactive graphics that need frequent updates. This guide covers canvas fundamentals and practical examples for sysadmins and developers…
Xen remains a solid hypervisor choice for specific workloads, though KVM dominates most Linux distributions today. This guide covers installing a paravirtualized DomU on Xen using modern tooling and Rocky Linux 9, which requires specific kernel parameters during installation. Why Paravirtualization Matters Paravirtualized guests communicate directly with the hypervisor rather than emulating hardware, resulting in…
Data visualization transforms raw metrics into actionable insights. When you’re managing infrastructure metrics, application logs, business KPIs, or system performance data, visualization is how you extract signal from noise. The human brain processes visual information faster and more reliably than log files or spreadsheet rows—which is why dashboards have become essential infrastructure in modern operations….
Picking your first programming language matters, but it’s not the career-defining decision some make it out to be. What matters more is that you pick something reasonable and start building. That said, some choices will save you months of frustration. Know What You’re Optimizing For Before evaluating languages, answer these questions honestly: What do you…
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…
Filtering dependent fields based on parent field values is a common requirement in Dynamics 365 CRM. This guide walks through implementing conditional filtering so the salutation dropdown only shows values relevant to the selected gender. Prerequisites Access to a Dynamics 365 environment (2016 or later) with customization rights Basic understanding of option sets and form…