Programming

Development Best Practices

Switching Between Simplified and Traditional Chinese in iBus Libpinyin
ByEric Ma Mar 24, 2018Apr 13, 2026

To toggle between Simplified Chinese and Traditional Chinese input modes in ibus-libpinyin, press Ctrl+Shift+F. This shortcut has been the standard method since ibus-pinyin 1.3.7 and works across modern versions. Common ibus-libpinyin Shortcuts Beyond script conversion, these shortcuts handle daily input tasks: Shortcut Function Ctrl+Shift+F Toggle Simplified/Traditional Chinese Ctrl+. Toggle full-width/half-width punctuation Ctrl+, Toggle English/Chinese punctuation…

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Scripting & Utilities

Multi-Hop SSH Connections with ProxyJump and ProxyCommand
ByEric Ma Mar 24, 2018Apr 12, 2026

When you need to reach a server through one or more intermediate hosts, you can establish a direct connection without manually chaining SSH sessions. This is essential for accessing internal servers that aren’t directly reachable from your workstation. The scenario laptop —-> proxy —-> server You want to connect to server.example.com through proxy.example.com as if…

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Design Patterns & Architecture

Understanding Hadoop Configuration Files: Locations and Defaults
ByEric Ma Mar 24, 2018Apr 13, 2026

Hadoop uses three primary configuration files to define YARN, HDFS, and MapReduce behavior: HDFS: hdfs-site.xml YARN: yarn-site.xml MapReduce: mapred-site.xml These files live in $HADOOP_HOME/etc/hadoop/ and override the built-in defaults when present. Finding Official Default Values Apache publishes default configuration documentation for each release. For current versions: Hadoop 3.4.x (Latest) HDFS defaults: https://hadoop.apache.org/docs/r3.4.0/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml YARN defaults: https://hadoop.apache.org/docs/r3.4.0/hadoop-yarn/hadoop-yarn-common/yarn-default.xml…

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Development Best Practices

Understanding YARN: Resource Management and Cluster Fundamentals
ByEric Ma Mar 24, 2018Apr 12, 2026

YARN (Yet Another Resource Negotiator) fundamentally restructured Hadoop 2.0 by decoupling resource management from application logic. If you’re transitioning from Hadoop 1.x or building systems on top of YARN, understanding its architecture is essential for effective cluster administration and application development. Essential Reading The foundational paper Start with “Apache Hadoop YARN: Yet Another Resource Negotiator”…

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Web Development

Converting LaTeX Documents with Figures to HTML
ByEric Ma Mar 24, 2018Apr 12, 2026

Converting LaTeX to HTML while preserving figures is essential when publishing technical documentation online. The right tool depends on your document complexity and output requirements. tex4ht (htlatex) tex4ht is the most reliable option for LaTeX documents with figures, math, and complex formatting. It’s part of the TeX Live distribution and available on all major platforms….

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System Administration & Cloud

Custom Headers and Footers in Apache Directory Listings
ByEric Ma Mar 24, 2018Apr 12, 2026

Custom headers and footers in Apache directory listings let you add branding, instructions, or navigation without modifying the core file listing. This is useful for public file archives, download directories, or any indexed directory you want to customize. Basic Setup with .htaccess Add these directives to .htaccess in the directory where you want custom listings:…

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Linux & Systems Administration

Remapping Modifier Keys on Linux
ByEric Ma Mar 24, 2018Apr 12, 2026

Remapping modifier keys on Linux makes sense if you’re an Emacs power user, prefer ergonomic hand positioning, or simply don’t use the Win key. The standard approach moves frequently-used modifiers closer to your thumbs by trading the underutilized Super/Win key for additional Ctrl or Alt access. A typical remapped layout looks like: |Ctrl|Alt|Ctrl| Space Bar…

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Design Patterns & Architecture

Configuring Hadoop Classpath for MapReduce Compilation
ByEric Ma Mar 24, 2018Apr 13, 2026

When compiling MapReduce jobs against a Hadoop installation, you need to include the correct classpath to resolve Hadoop dependencies. The yarn classpath command handles this automatically. Getting the classpath Run this command to output the full classpath: yarn classpath If yarn isn’t in your $PATH, use the full path: $HADOOP_HOME/bin/yarn classpath Replace $HADOOP_HOME with your…

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Linux & Systems Administration

Memory Leak Detection Tools for C on Linux
ByEric Ma Mar 24, 2018Apr 12, 2026

Memory leak detection is critical for C program reliability. Several tools work at different stages of development—compile time, runtime, and production scenarios. Your choice depends on performance tolerance, integration needs, and how much detail you require. AddressSanitizer (ASan) AddressSanitizer is the first tool to reach for in 2026. It’s compiler-integrated, fast, and catches a broader…

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Linux System Configuration

Alt-Tab Between Windows Only in GNOME
ByEric Ma Mar 24, 2018Apr 13, 2026

GNOME’s default Alt-Tab behavior switches between applications, grouping all windows from the same app together. If you work with multiple windows in a single application—multiple browser tabs, text editors, or terminals—this becomes frustrating. Here’s how to change it to window-based switching. Using the Alternate Tab Extension The simplest approach is enabling GNOME’s built-in Alternate Tab…

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Linux System Configuration

Changing the Default OS in a Windows Dual Boot Setup
ByEric Ma Mar 24, 2018Apr 12, 2026

If you’re running a dual-boot system with Windows, you’ll need to configure which operating system loads by default. The method depends on your Windows version and whether you’re using legacy BIOS or UEFI firmware. Windows 7 and Vista: System Properties Method For Windows 7 systems using the traditional boot manager: Open Control Panel and navigate…

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Development Best Practices

dd on Windows: WSL2, Cygwin, and Native Alternatives
ByEric Ma Mar 24, 2018Apr 12, 2026

dd is a powerful utility for reading and writing raw data to block devices. While it’s a Linux standard, you have several options for using it on Windows systems. WSL2: The Modern Approach For Windows 10 (21H2+) and Windows 11, Windows Subsystem for Linux 2 (WSL2) is the best choice. It provides a full Linux…

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Linux System Configuration

Fix gthumb Hanging When USB Devices Are Connected
ByEric Ma Mar 24, 2018Apr 13, 2026

When gthumb hangs during startup after connecting an iPhone, external drive, or other USB device, the issue typically stems from gthumb attempting to enumerate mounted storage devices during initialization. Certain filesystem states, permissions misconfigurations, or slow I/O can cause the process to block indefinitely. Quick fix: unmount the device The most straightforward solution is to…

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Web Development

Responsive CSS Loading with Media Queries and @import
ByEric Ma Mar 24, 2018Apr 13, 2026

You can use @import with media queries to conditionally load CSS files only for specific viewport sizes. This is useful for loading layout-specific stylesheets, web fonts, or icon libraries only when needed. Basic Syntax The general format is: @import url(‘path/to/file.css’) media-query; The media query parameter controls when the stylesheet loads. Here are practical examples: /*…

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Development Best Practices

Running Emacs in Terminal-Only Mode
ByEric Ma Mar 24, 2018Apr 13, 2026

If you want Emacs to run in the terminal without opening an X window, you have several practical options depending on your setup and workflow. Option 1: Install emacs-nox (Recommended for servers) The cleanest approach is installing the no-X variant of Emacs, which is built without X11 support. This reduces memory overhead and startup time…

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Linux System Configuration

Boot Windows from GRUB2 Command Line
ByEric Ma Mar 24, 2018Apr 13, 2026

If you need to boot Windows from the GRUB2 command line—whether during troubleshooting, recovery, or when your boot configuration is broken—you can do it with a few commands. This guide covers both BIOS and UEFI systems. Quick boot for BIOS systems Assuming Windows is installed on the first partition of the first disk in NTFS…

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Development Best Practices

Installing Fedora on MBR Disks
ByEric Ma Mar 24, 2018Apr 12, 2026

If you’re working with legacy BIOS systems and MBR partition tables, Fedora’s installer can sometimes misdetect your firmware mode and attempt UEFI/GPT setup on hardware that only supports legacy BIOS. This guide covers the proper approach for Fedora 39+ on MBR systems. Prerequisites Before starting, verify your system configuration: Boot the installer in legacy BIOS…

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Linux System Configuration

Find Which RPM Package Provides a Command in Fedora
ByEric Ma Mar 24, 2018Apr 13, 2026

When you need to identify which package installed a command on your Fedora system, you have several reliable methods depending on whether the package is already installed. Quick lookup for installed commands The fastest approach combines which to locate the command with rpm to query the owning package: $ rpm -qf $(which ping) iputils-8.40-4.fc40.x86_64 The…

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Linux & Systems Administration

Debugging Linux Network Drivers: Essential Tools and Techniques
ByEric Ma Mar 24, 2018Apr 12, 2026

When network interfaces fail or behave unexpectedly, you need to inspect driver details, hardware state, and kernel messages. Here’s the practical toolkit for diagnosing network hardware and driver issues. Kernel Messages and Logs Start by checking kernel logs where driver initialization and errors are recorded: dmesg | grep -i network dmesg | grep -i driver…

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Design Patterns

Configure Windows Proxy Settings via Command Line
ByEric Ma Mar 24, 2018Apr 13, 2026

For any current Windows system, netsh winhttp is the standard command-line tool for proxy configuration. WinHTTP handles system-level proxy settings used by Windows Update, built-in applications, and services that don’t rely on browser-specific configuration. Set a proxy with bypass list netsh winhttp set proxy proxy-server=”proxy.example.com:8080″ bypass-list=”localhost;127.0.0.1;*.internal.local” Use semicolons to separate multiple proxy servers or bypass…

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