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Linux & Systems Administration

Configuring Network Interfaces with ifcfg Files on RHEL
ByEric Ma Mar 24, 2018Apr 13, 2026

The /etc/sysconfig/network-scripts/ directory contains network configuration files on RHEL and Fedora systems. While newer systems increasingly use NetworkManager and systemd-networkd, understanding ifcfg files remains essential for legacy systems and certain enterprise environments. Basic Static IP Configuration Here’s a typical ifcfg-eth0 file for a static IP setup: DEVICE=eth0 TYPE=Ethernet BOOTPROTO=none ONBOOT=yes IPADDR=192.168.1.151 NETMASK=255.255.0.0 GATEWAY=192.168.1.10 USERCTL=no The…

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Linux & Systems Administration

Converting PowerPoint Slides to High-DPI TIFF for Print
ByEric Ma Mar 24, 2018Apr 11, 2026

PowerPoint’s export function defaults to 96 DPI, which is suitable for screen display but inadequate for printing posters, documents, or any material requiring high resolution. While PowerPoint includes DPI settings, they’re often unreliable or have limited effect on TIFF output. Here are the practical methods to generate proper high-DPI TIFF files from PowerPoint slides. PowerPoint’s…

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Linux & Systems Administration

Converting PDFs to Text While Preserving Layout on Linux
ByEric Ma Mar 24, 2018Apr 13, 2026

Many PDF-to-text conversions strip away formatting and spatial relationships, making tables unreadable and multi-column layouts collapse into linear text. If you need to preserve the relative positions of text elements—especially tables, columns, and indentation—you have several solid options. pdftotext with layout preservation The simplest approach is pdftotext, which comes with most distributions as part of…

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Linux & Systems Administration

Extracting File Extensions in Python with pathlib and os.path
ByEric Ma Mar 24, 2018Apr 13, 2026

The most reliable way to get a file extension in Python is os.path.splitext(), which splits a filename into the base name and extension. For modern code, pathlib.Path provides a cleaner alternative. Using os.path.splitext() os.path.splitext() returns a tuple of (name, extension): import os name, ext = os.path.splitext(‘file.txt’) print(name) # ‘file’ print(ext) # ‘.txt’ This works with…

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Linux & Systems Administration

Setting Up HP Scanner on Linux with SANE
ByEric Ma Mar 24, 2018Apr 11, 2026

Once your HP printer is working on a Linux system, enabling the scanner requires installing SANE (Scanner Access Now Easy) and HP-specific backends. If wireless connectivity is already established for printing, the scanner should be discoverable on the same network. Install Required Packages On Fedora: sudo dnf install sane-backends sane-backends-devel hplip hplip-common On Ubuntu/Debian: sudo…

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Development Best Practices

Double-Blind Peer Review: How It Works
ByWeiwei Jia Mar 24, 2018Apr 13, 2026

Double-blind peer review is a standard evaluation process used by many academic conferences and journals, particularly in computer science. Understanding how it works is essential before submitting your paper. What is Double-Blind Review? Double-blind review means that reviewers and authors remain anonymous to each other throughout the evaluation process. Neither party knows the identity of…

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Linux & Systems Administration

Editing EPS Files on Linux: Tools and Methods
ByEric Ma Mar 24, 2018Apr 13, 2026

EPS (Encapsulated PostScript) files are vector graphics commonly used in academic papers, technical documentation, and professional publishing. If you need to modify an EPS file, you have several options depending on your workflow and the complexity of edits required. Using Inkscape Inkscape is the most straightforward tool for editing EPS files on Linux. It’s a…

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Linux & Systems Administration

Extract Directory and Filename from File Paths in Bash
ByEric Ma Mar 24, 2018Apr 13, 2026

When you have an absolute path like /foo/bar/baz.txt and need to split it into its components, Bash provides two essential utilities: dirname and basename. Using dirname and basename The dirname command returns the directory portion of a path, while basename returns just the filename: p=”/foo/bar/baz.txt” dirname “$p” # Output: /foo/bar basename “$p” # Output: baz.txt…

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Scripting & Utilities

Open Source Document Scanning Tools for Windows
ByEric Ma Mar 24, 2018Apr 13, 2026

If you need to scan documents on Windows, several solid open-source options exist. Here are the most practical choices. NAPS2 (Not Another PDF Scanner 2) NAPS2 remains the top recommendation for Windows scanning. It’s straightforward, actively maintained, and handles most scanner hardware without headaches. What it does: Scans from WIA and TWAIN-compatible scanners Saves to…

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Programming Languages

Recovering Data from a Failed Hard Drive
ByEric Ma Mar 24, 2018Apr 12, 2026

When a hard drive fails physically, data recovery becomes challenging but sometimes possible. If the drive isn’t recognized by the system or showing signs of mechanical failure, professional recovery services may be necessary—but they’re expensive. Before going that route, you can attempt recovery yourself using open-source tools. When to attempt DIY recovery You can safely…

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Linux & Systems Administration

Merging Multiple PDFs on Linux
ByEric Ma Mar 24, 2018Apr 13, 2026

Merging PDFs on Linux is straightforward with several tools available, each suited to different needs. Whether you need a quick command-line merge or want to reorder pages visually, here’s what works best. pdfunite: The Simplest Approach The fastest way to merge PDFs is with pdfunite from poppler-utils: pdfunite file1.pdf file2.pdf file3.pdf output.pdf Install it if…

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Linux & Systems Administration

Converting PowerPoint Slides to PNG and JPG on Linux
ByEric Ma Mar 24, 2018Apr 13, 2026

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…

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Scripting & Utilities

Excluding Directories by Name Pattern in rsync
ByEric Ma Mar 24, 2018Apr 13, 2026

When backing up with rsync, you often need to skip directories like cache/, node_modules/, or .git/ that appear at multiple levels in your directory tree. Listing every instance individually is impractical, but rsync’s exclude patterns handle this elegantly. Basic exclude syntax The simplest approach uses –exclude with a directory name pattern: rsync -avxP –exclude=cache/ /path/to/src/directory/…

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Linux & Systems Administration

Merge JPG Images into PDF on Linux
ByEric Ma Mar 24, 2018Apr 13, 2026

Converting a series of JPG images into a single PDF is useful for creating documents, presentations, or archiving scanned photos. Linux offers several tools for this task, each with different trade-offs between simplicity, quality preservation, and features. Using img2pdf (Recommended) For most cases, img2pdf is the best choice because it merges images without re-encoding or…

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Linux & Systems Administration

HDFS Snapshots: Architecture and Implementation Details
ByEric Ma Mar 24, 2018Apr 11, 2026

HDFS snapshots provide a way to create read-only point-in-time copies of the filesystem or specific directories without duplicating data. Understanding their design helps you implement efficient backup strategies and recover from accidental deletions in production clusters. How HDFS Snapshots Work Snapshots in HDFS use copy-on-write semantics to avoid duplicating data. When you create a snapshot,…

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Linux & Systems Administration

Installing GitBook on Linux
ByEric Ma Mar 24, 2018Apr 13, 2026

GitBook is a tool for building documentation and ebooks from Markdown content. Here’s how to set it up on a Linux system. Prerequisites You’ll need Node.js installed first. On Ubuntu/Debian: curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash – sudo apt-get install -y nodejs On Fedora/RHEL: sudo dnf install nodejs Verify the installation: node –version npm…

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Linux & Systems Administration

Installing and Configuring a PDF Reader on Linux Mint
ByEric Ma Mar 24, 2018Apr 13, 2026

Adobe Reader (acroread) is rarely the best choice for Linux users anymore. It’s unmaintained, doesn’t receive security updates, and performs poorly compared to modern alternatives. This guide covers better options and how to set up a functional PDF viewer on Linux Mint. Why Not Adobe Reader? Adobe stopped supporting Reader for Linux in 2013. The…

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Linux & Systems Administration

x86-64 Floating-Point Comparisons with SSE and AVX
ByEric Ma Mar 24, 2018Apr 12, 2026

The x86-64 ISA provides ucomiss and ucomisd for comparing SSE floating-point values. These instructions compute S1 – S2 and set the EFLAGS register (ZF, PF, CF) based on the result. Instruction Operands Purpose ucomiss S2, S1 Compare single-precision (32-bit) floats ucomisd S2, S1 Compare double-precision (64-bit) floats In AT&T syntax, the source operand is listed…

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Linux & Systems Administration

Viewing and Converting DVI Files on Linux
ByEric Ma Mar 24, 2018Apr 13, 2026

DVI (Device Independent) files are the output format from TeX and LaTeX compilers. While modern workflows typically generate PDF directly with pdflatex, you’ll still encounter DVI files in legacy documents, archived projects, and specific publishing pipelines that require intermediate processing. Viewing DVI Files Xdvi Xdvi is the most reliable dedicated DVI viewer and remains the…

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Testing & DevOps

Balancing Text Columns on the Last Page in LaTeX
ByEric Ma Mar 24, 2018Apr 13, 2026

When using two-column layouts, the last page often ends with uneven column heights—one column noticeably longer than the other. This looks sloppy in formal documents. Two main packages solve this: balance and flushend. Using the balance package The balance package gives you explicit control over where balancing happens. Add to your preamble: \usepackage{balance} Then insert…

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