cgdb is a curses-based frontend to gdb that keeps your source code visible while you debug. Unlike raw gdb, it splits the interface into two panes: source code on top, gdb command prompt below. If you’re already comfortable with Vim keybindings, cgdb feels natural—it uses the same navigation keys and modal editing paradigms you’re used…
GDB is the standard debugger for C/C++ development on Linux. This reference covers essential commands for breakpoints, execution control, inspection, and troubleshooting common debugging scenarios. Starting GDB gdb ./program gdb ./program core.dump # Debug with core file gdb -p <pid> # Attach to running process gdb –args ./program arg1 arg2 # Pass arguments to program…
Serial communication remains essential for embedded systems, microcontroller programming, and legacy hardware integration. The Win32 API provides direct control over COM ports through a straightforward set of functions: CreateFile() to open the port, GetCommState() and SetCommState() to configure parameters, and ReadFile()/WriteFile() for I/O operations. Opening the COM Port Start by opening the port with appropriate…
When debugging and optimizing C/C++ programs, you need to see how the compiler translates your source code into assembly. A mixed source and assembly listing lets you trace exactly what machine instructions correspond to each line of your source. Using objdump (Recommended Modern Approach) The most straightforward method is to compile with debugging symbols and…
Managing proxy settings through the GUI is tedious, especially when you need to switch between multiple proxy servers frequently. Rather than hunting through settings menus each time, command-line tools eliminate friction and enable scripted deployments across your infrastructure. The original SetProxy tool is outdated and incompatible with modern Windows versions. Use netsh or PowerShell instead—both…
Blocking window closure in MFC applications is necessary for critical operations, multi-step dialogs, and workflows that require user confirmation before exit. This requires handling both the close button and the Alt+F4 keyboard shortcut. Removing the Close Button from the System Menu The simplest approach is to remove SC_CLOSE from the system menu in your dialog’s…
OCaml is a practical functional language with strong static typing and pattern matching. If you’re coming from systems programming or looking to add functional paradigms to your toolkit, these resources will accelerate your learning. Primary Learning Resources Real World OCaml by Yaron Minsky, Anil Madhavapeddy, and Jason Hickey remains the standard reference for modern OCaml…
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>…
Converting raster images to EPS format is necessary when working with LaTeX documents or professional publishing workflows that require PostScript compatibility. While online converters exist, command-line tools give you reproducibility, automation, and batch processing capabilities—essential for production work. Why EPS Still Matters EPS (Encapsulated PostScript) embeds images with precise positioning metadata and works reliably with…
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…
Apache’s default 404 error page is generic and often displays hosting provider branding. Customizing it gives you control over the user experience when they land on missing pages. The same applies to other HTTP error responses like 403 Forbidden or 500 Internal Server Error. Apache: Using ErrorDocument Directive The ErrorDocument directive in Apache accepts two…
Moving a domain requires more than DNS changes. If you have existing traffic, backlinks, or search engine indexing pointing to your old domain, a proper 301 redirect ensures users and search engines find your content at the new location while preserving SEO rankings. Why 301 Redirects Matter A 301 (“Moved Permanently”) response tells browsers and…
When managing Xen Dom0 hosts, shutting down guest VMs (DomUs) before powering off the physical server is essential to prevent data loss and filesystem corruption. Modern Xen distributions (including Citrix Hypervisor and AWS infrastructure) still rely on this principle, though the tooling has evolved. Using xl for VM Shutdown Current Xen installations use xl rather…
Running the same command across dozens of servers is a routine task in infrastructure work. Whether you’re checking disk usage, deploying updates, or gathering system metrics, doing this manually wastes time and introduces errors. The straightforward approach: iterate through a list of hosts and execute commands via SSH on each one. Basic Shell Loop Approach…
When managing multiple servers, you need reliable ways to verify which hosts are reachable. While orchestration tools like Kubernetes and Ansible handle monitoring at scale, a lightweight Bash script works well for quick spot checks, operational tasks, or smaller deployments. Basic ICMP Reachability Check The simplest approach uses ping to test ICMP reachability: ping -W…
Emacs provides a built-in tutorial. Access it with: C-h t For structured learning, the GNU Emacs Manual (built-in via C-h i) is the most authoritative resource. The Emacs Wiki also maintains community-driven guides and examples. Emacs configuration Store your configuration in ~/.emacs.d/init.el rather than the legacy ~/.emacs file. This keeps your Emacs directory cleaner and…
Scala runs on the Java Virtual Machine, so you’ll need Java 11 or later installed first. Check your current version: java -version If you don’t have Java installed, install it through your distribution’s package manager or use a tool like SDKMAN. Installing via SDKMAN (Recommended) SDKMAN is the most reliable way to manage Scala and…
The diff utility generates unified diffs that show changes between file versions. Always use the -u flag to create unified diffs, which are the standard format for patches. For a single file: diff -u original.c new.c > fix.patch For an entire directory tree: diff -rupN original/ new/ > patchfile.patch The flags break down as: -r:…
The mupdf package is available in most major Linux distributions. On RHEL/CentOS/Fedora: sudo dnf install mupdf mupdf-tools On Debian/Ubuntu: sudo apt install mupdf On Arch: sudo pacman -S mupdf mupdf is a lightweight, fast PDF and XPS viewer written in C. It’s significantly faster than heavier alternatives like Evince or Okular, making it ideal for…
Fedora switched to systemd for service management years ago, replacing the traditional /etc/inittab file with a target-based system. While systemctl set-default is the standard approach, understanding the manual method gives you insight into how systemd actually manages boot targets. Systemd Targets vs. Legacy Runlevels Systemd uses targets instead of runlevels. The two primary targets you’ll…