Vim’s indentation system provides multiple approaches for formatting C/C++ code, from built-in operators to external formatters. The native tools work reliably for most tasks, while external formatters enforce stricter style rules when needed. The Indentation Operator and Text Objects The = operator re-indents text. It requires a motion or text object to specify what to…
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…
The C language itself provides no built-in mechanisms for input/output, memory management, string manipulation, or process control. These essential capabilities come from the C standard library — a collection of functions, macros, and data types that you link with your programs at compile time. The GNU C Library (glibc) is the standard C library used…
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…
fclose() closes a file stream and disassociates it from its underlying file descriptor. It’s part of the C standard library, defined in <stdio.h>. #include <stdio.h> int fclose(FILE *stream); When called, fclose() flushes buffered output, closes the file descriptor, and deallocates the FILE structure. The function works with both input and output streams. After fclose() returns,…
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…
Converting strings to integers is a fundamental operation in C++, but the method you choose affects both code clarity and performance. Here are the four main approaches, ranked by use case. std::stoi() — The Default Choice std::stoi() is the standard C++11 method for most situations. It’s exception-based, handles whitespace automatically, and works with custom number…
Connecting to MySQL from JSP requires the mysql-connector-j JDBC driver and proper connection handling. The old mysql-connector-java artifact is deprecated—switch to mysql-connector-j, which supports MySQL 8.0+ with modern SSL/TLS, authentication plugins, and performance improvements. Dependency Management Add mysql-connector-j via Maven or Gradle. Maven is standard for modern Java projects: <dependency> <groupId>com.mysql</groupId> <artifactId>mysql-connector-j</artifactId> <version>8.4.0</version> </dependency> For…
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…
Self-hosting WordPress gives you control over your domain, design, content, and monetization—something you don’t get with WordPress.com or other hosted solutions. The reality: it’s feasible on a tight budget, but free hosting isn’t the answer. Why Self-Host? Hosted solutions lock you in. You can’t control your domain, customize templates deeply, manage backups reliably, or implement…
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…
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…
Insert the installation media and create a mount point: sudo mkdir -p /media/dvd sudo mount /dev/sr0 /media/dvd For a DVD image file instead of physical media: sudo mount -o loop /path/to/image.iso /media/dvd Verify the mount and check that packages exist: ls /media/dvd/Packages/ | head On systems with automatic mounting (systemd-based), the DVD may already be…
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…
Qt and GTK applications often use different cursor themes, which creates visual inconsistency across your desktop. This mismatch is common in mixed-DE environments where Qt applications (like VLC, KeePass, or Telegram) inherit the wrong cursor style from system defaults. How Qt finds cursor themes Qt applications read cursor configuration from ~/.icons/default/index.theme. This file specifies which…