To replace text containing newline characters in Emacs, you need to insert actual newline characters in the replacement string rather than literal \n sequences. Using C-q C-j for interactive replacement The standard approach uses quoted-insert to insert special characters literally: C-q invokes quoted-insert C-j inserts a literal newline (LF, ASCII 10) Open the find and…
UDP packet loss on Linux commonly stems from undersized kernel buffers. When packets arrive faster than the application can process them, the kernel drops excess datagrams silently. Unlike TCP, UDP offers no retransmission, so these losses are permanent. Proper buffer tuning is essential for DNS servers, NTP, monitoring systems, video streaming, and any high-throughput UDP…
The HTML5 <video> element is the standard for embedding video content without plugins. It’s supported across all modern browsers and provides native playback controls, accessibility features, and performance benefits. Basic Video Embedding The simplest approach uses the <video> element with a <source> tag: <video controls> <source src=”path/to/file.mp4″ type=”video/mp4″> Your browser does not support the video…
The fclose theme is a lightweight Question2Answer theme distributed as a set of PHP and CSS files. It provides a clean base layout that you can extend with custom styling and icon sets. Getting the Theme Files You need two core files to run fclose: qa-theme.php — The theme class that extends qa_html_theme_base and controls…
When processing text files or command output, non-printable ASCII characters corrupt formatting, break parsing, or create unexpected behavior. You need the right tool for your specific case — whether you’re stripping control characters, handling UTF-8, or cleaning up embedded escape sequences. Understanding Printable ASCII The standard printable ASCII range includes: Tab (hex 09) Line Feed…
If you need millisecond precision timestamps from the command line, there are several approaches depending on your use case and system requirements. Using date with %3N The simplest and most reliable method on modern GNU coreutils (8.32+) is: date +%s%3N This outputs seconds since epoch followed by exactly three digits of nanosecond precision (milliseconds). Example…
To determine file size in C, use stat() to populate a struct stat and read the st_size field. Here’s the correct approach: #include <sys/stat.h> #include <stdio.h> off_t file_length(const char *path) { struct stat st; if (stat(path, &st) == -1) { perror(“stat”); return -1; } return st.st_size; } Why off_t and not long Using off_t as…
Eclipse CDT has evolved to handle CMake projects effectively. The key is understanding which approach fits your workflow — native CMake integration (recommended for 2023+ versions) or generating build files. Native CMake Integration (Recommended) Eclipse CDT 2023 and later include robust native CMake support. This is the simplest approach for new projects or when you…
When a process receives a signal from kill or pkill, it needs a signal handler to intercept and respond to it. Without one, most signals terminate the process immediately. This guide covers setting up robust signal handlers for production daemons. Understanding Signals The kill command sends signals to processes. By default, it sends SIGTERM (signal…
Git branching is fundamental to modern development workflows. A branch is a lightweight pointer to a commit that lets you work on multiple features, fixes, or experiments in parallel without affecting the main codebase. Understanding branching well is essential for team collaboration and maintaining a clean project history. Creating and Switching Branches Create a new…
The primary keyboard shortcut for formatting code in Eclipse is Ctrl + Shift + F. This reformats your entire active file according to your configured code style settings without requiring any text selection. When you press Ctrl + Shift + F, Eclipse adjusts indentation, spacing, line breaks, and bracket placement across the file. To format…
The most straightforward approach is whitespace-mode, which provides built-in visual feedback for lines exceeding a specified column width. Add this to your Emacs configuration: (require ‘whitespace) (setq whitespace-style ‘(face empty tabs lines-tail trailing)) (setq whitespace-line-column 80) (global-whitespace-mode t) The lines-tail style highlights only the portion of the line exceeding whitespace-line-column, which is less visually intrusive…
X11 forwarding lets you run Chrome on a remote host and display it on your local machine. It’s quick to set up for occasional use, but for regular work or modern Linux systems, you’ll want to know when to use alternatives. Basic X11 Forwarding The simplest approach uses SSH’s X11 forwarding: ssh -X username@remote_host google-chrome…
Viewing file contents in hexadecimal is essential for debugging binaries, inspecting file headers, analyzing corrupted data, and understanding file formats. Linux provides several tools for this, each with different strengths. xxd xxd is the most commonly used hex viewer. By default, it displays hex on the left and ASCII representation on the right: xxd file.txt…
Emacs handles line ending conversions through its buffer coding system. Whether you’re converting CRLF (DOS/Windows) to LF (Unix) or the reverse, the process is straightforward. DOS to Unix (CRLF to LF) Open the file in Emacs and run: M-x set-buffer-file-coding-system RET undecided-unix Or use the keyboard shortcut: C-x RET f undecided-unix Then save the file:…
The simplest approach is to select text and run untabify: M-x untabify This replaces all tabs in the selected region with spaces, preserving column alignment. If no region is active, Emacs prompts you to define one. Convert the Entire Buffer Select all content, then run untabify: C-x h M-x untabify C-x h selects the whole…
To see the current file path immediately, use the Elisp evaluation prompt: M-: buffer-file-name This displays the full path in the echo area. Alternatively, press M-x, type eval-expression, and enter buffer-file-name. In Elisp code Reference buffer-file-name directly in your configuration or custom commands: (message “Editing: %s” buffer-file-name) This prints to the echo area and logs…
Chrome aggressively caches HTTP redirects—especially 301 (permanent) and 308 redirects—as a performance optimization. The cache persists across browser sessions, which causes real problems when you’ve updated redirect rules and need to test them immediately. Understanding Chrome’s Redirect Cache Behavior Chrome stores redirect information at the browser level, separate from typical page caches. This means: 301…
You can fetch a webpage as if you’re requesting from a mobile device by setting curl’s User-Agent header to match a mobile browser. Remote servers use the User-Agent header to decide whether to serve mobile or desktop versions of pages. Basic syntax Use the -A (or –user-agent) flag to specify a mobile User-Agent string: curl…
The built-in etags command doesn’t recursively traverse directories by default, but generating TAGS files across your entire project is straightforward with the right tools and setup. Using ctags (Recommended) The simplest approach is ctags with the -e flag, which generates Emacs-compatible TAGS files: ctags -e -R . The -R flag enables recursive traversal. This works…