Programming language tutorials, syntax guides, and language-specific features.
GNU Screen is a terminal multiplexer that lets you manage multiple shell sessions within a single window. If you’re new to it, here are the best resources to get up to speed, plus practical tips for getting started. Getting Started with Screen For an introduction to the basics, start with A quick tutorial on screen….
The core problem here is legitimate: if you’re running multiple jobs on the same dataset where the mapper phase produces identical intermediate results, recomputing those results is wasteful. However, skipping the mapper phase entirely breaks MapReduce’s processing model. There are better approaches. Why You Can’t Just Skip the Mapper MapReduce assumes data flows through map…
HDFS doesn’t natively support directory-level replication factor inheritance. Even if you set a specific replication factor on a directory and its files, new files created in that directory will default to the cluster’s global dfs.replication setting (typically 3). This limitation can complicate multi-tier storage strategies where you want temporary or low-priority data on fewer replicas…
MPlayer has been largely superseded by mpv in most Linux distributions, but if you need the classic MPlayer with DVD navigation support, building from source remains the way to get libdvdnav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…
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…
A USB drive that’s mounted as read-only is frustrating — you can read files but can’t write, delete, or modify anything. This usually happens due to filesystem issues, hardware problems, or missing drivers. Check the Current State First, identify how the drive is mounted and what filesystem it uses: lsblk -f Look for your USB…
MPlayer is largely unmaintained as of 2026. For playing 3D movies on standard displays, mpv is the modern replacement and offers better stereo rendering support. Using mpv for 3D Playback The most straightforward approach with mpv is to use the stereo3d filter to convert side-by-side or other 3D formats to anaglyph (color-separated) stereo: mpv –vf=stereo3d=sbsl:arced…
When the Scala compiler emits warnings like deprecation notices, you need to pass compiler flags to see the details. The solution is to configure scalacOptions in your sbt build. Session-Only Configuration During an interactive sbt session, add options temporarily: set scalacOptions += “-deprecation” This applies only to the current session and is lost after reload…
These four languages share functional programming roots but diverge significantly in syntax and design philosophy. Here’s a practical reference for anyone transitioning between them or evaluating which to use. Basic Function Definition OCaml: let add x y = x + y let rec factorial n = if n <= 1 then 1 else n *…
This guide covers setting up PHP with Apache’s httpd on Fedora systems. The setup provides standard PHP support suitable for most development and production environments. Install Apache httpd Start by installing the Apache web server package: sudo dnf install httpd On Fedora 22 and later, dnf is the default package manager (replacing yum). If you’re…
The hex() function converts an integer to a hexadecimal string with a 0x prefix: i = 255 print(hex(i)) # Output: 0xff This works for negative numbers too: print(hex(-42)) # Output: -0x2a String formatting for control For more control over the output, use f-strings or the format() method with format specifiers: i = 255 print(f”Value: {i:x}”)…
HTML character encoding determines how characters are represented in your source code and rendered in browsers. UTF-8 is the standard, but understanding when and how to use character entities remains essential for reserved characters, symbols, and special cases. UTF-8: The Default Standard Modern HTML5 documents should always declare UTF-8 encoding: <!DOCTYPE html> <html lang=”en”> <head>…
Displaying widgets selectively based on page context, user conditions, or post-specific rules is a common requirement in WordPress. Rather than relying on legacy plugins or wrestling with limited built-in options, you can implement this directly in your theme or custom plugin using WordPress hooks and conditional tags. Why Custom Implementation Over Plugins The Widget Logic…
BBCode is a lightweight markup language commonly used in forums and legacy content systems. It’s simpler than HTML and more readable in raw form. While WordPress focuses on its block editor and native HTML support, you can add BBCode parsing if your content or users require it—though in most cases, modern alternatives are better choices….
Google stopped updating the PageRank toolbar in 2016 and fully deprecated the public metric by 2024. If you’re still thinking about PageRank as a ranking factor, you’re optimizing for something that hasn’t mattered in over a decade. The PageRank Story PageRank was Google’s original link-based ranking signal — a score from 0-10 displayed in the…
RGBlite is a lightweight WordPress theme released in 2010 that features a green-red-blue color scheme and minimal design. While functional for its time, the theme is no longer actively maintained and predates modern WordPress standards by over a decade. This guide covers how to install and configure it if you’re working with legacy systems, plus…
The default 13px font size in WordPress’s block editor can strain your eyes, especially on high-resolution displays or during extended editing sessions. Several approaches let you adjust editor typography without touching core files. Using the Site Editor (Easiest) For block themes and WordPress 5.9+, the visual Site Editor is the simplest route: Navigate to Appearance…
The wp_count_posts() function returns a count object for any post type, making it essential for dashboards, theme displays, admin queries, and performance monitoring. Understanding how to use it correctly—and when to optimize—matters for WordPress development. Basic Usage <?php $count_posts = wp_count_posts(); $published = $count_posts->publish; echo $published . ” published posts”; ?> By default, wp_count_posts() counts…