Extracting images embedded in PDF files is straightforward on Linux with several reliable tools. Here are the most practical approaches, from GUI tools to command-line solutions. GUI Tools LibreOffice Draw remains the simplest option if you prefer a graphical interface. Open the PDF file in LibreOffice Draw, right-click on any image, and select “Save Image…
When stop-dfs.sh fails to cleanly terminate DataNode processes, you’re left with orphaned Java processes consuming resources and potentially causing cluster issues. This happens most often after ungraceful cluster shutdowns or when the standard stop script encounters communication problems with specific nodes. Understanding the Problem The typical symptom is stop-dfs.sh reporting that certain nodes have no…
If your iPhone contacts search is returning “No results” after an iOS update, the issue is often a corrupted contacts database or a syncing problem with your contacts source. Here are the most effective fixes. Check Your Contacts Source First, verify where your contacts are actually stored. Go to Settings > Contacts > Default Account…
Firefox on iOS has improved significantly since the early days, but understanding what syncs and what doesn’t remains important for managing bookmarks across devices. Current sync capabilities As of 2026, Firefox sync does support bookmarks across iOS and desktop, but with important limitations. When you enable Firefox sync on your iOS device and link it…
Finding quality free images for your website means balancing availability, licensing, and actual usability. While generic image search works, specialized repositories are faster and legally safer. Google Image Search (with license filtering) Google Images remains useful for locating free content, but the licensing filter is critical. Use the Advanced Search and filter by usage rights…
When a process mmaps and mprotects many memory ranges, you’ll eventually hit the kernel limit and start seeing ENOMEM errors from mprotect() calls. This happens because Linux maintains internal kernel structures for each mapped range, and there’s a hard ceiling on how many the kernel will track per process. The culprit is the vm.max_map_count sysctl…
When you connect an external keyboard to your laptop, accidental key presses from the built-in keyboard can be annoying. Disabling it entirely is straightforward on Linux and can save you from errant inputs while keeping the option to re-enable it when needed. Find Your Keyboard Device Start by listing all input devices to identify your…
Merging SAM files is a common task in bioinformatics workflows, and while samtools merge works directly with BAM files, you need a different approach for SAM files. The most efficient method leverages the SAM format structure: headers start with @, and alignment records don’t. Why not convert to BAM first? Converting SAM to BAM, merging…
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…
RealVNC’s free tier is limited to personal use and restricts advanced features, making it unsuitable for many production or semi-commercial scenarios. If you need a fully-functional open-source alternative, several solid options exist. TightVNC TightVNC remains a reliable choice for Windows VNC hosting. It’s GPL-licensed, fully open-source, and includes both server and client components. Installation: Download…
When submitting images to publishers or print shops, you’ll often need CMYK color space instead of RGB. The conversion is straightforward on Linux using ImageMagick’s convert command. Basic conversion The simplest approach uses the -colorspace option: convert from.tif -colorspace CMYK to.tif This works, but CMYK TIFF files can be quite large. Add compression to keep…
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…
The git diff –word-diff output is clean and readable for tracking changes at the word level instead of line-by-line. If you need that functionality outside a git repository—or just want a standalone tool—wdiff is purpose-built for exactly this. Using wdiff for word-level diffs wdiff compares two files word by word, where a word is defined…
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…
The TP-LINK T2U is a USB WiFi adapter based on the MediaTek MT7650U chipset. While Linux kernel support has improved significantly, you may still need to manually compile drivers on some distributions. This guide covers installation on modern Fedora and RHEL-based systems. Check if your adapter is already supported First, plug in the adapter and…
The free command—along with ps, top, kill, pgrep, and dozens of other system utilities—is maintained as part of the procps-ng project. Source repository The source code is hosted at: https://gitlab.com/procps-ng/procps You can clone it with: git clone https://gitlab.com/procps-ng/procps.git cd procps Most distributions package procps-ng, so you likely already have it installed. You can verify the…
Firefox Sync requires an email address and a password to function. The critical question: if someone gains access to your Firefox account or device, can they read your synced passwords without knowing your master password? The short answer: no. Only you with your password can decrypt your synced data. Mozilla’s servers cannot access your encrypted…
When you open a popup window with window.open(), you’ll often need to detect when the user closes it so you can update your UI, refresh data, or clean up resources. Here are the practical approaches, from polling to event-driven methods. Polling the closed property The simplest method is to periodically check the popup’s closed property:…
When you open a new window with window.open(), you often need to communicate between the parent (opener) window and the child (opened) window. The most straightforward approach is to access the opener window directly through the opener property. Basic Two-Way Communication In the parent window, define a variable: let exchangeVar = ”; From the child…
Serializing objects to JSON is a fundamental task in Node.js for APIs, databases, and file storage. The approach depends on your object complexity and performance requirements. Basic Conversion with JSON.stringify The standard approach uses the built-in JSON.stringify() method: const myObject = { name: ‘John’, age: 30, email: ‘john@example.com’ }; const jsonString = JSON.stringify(myObject, null, 2);…