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…
If you’ve pushed a commit with a bad message, you can fix it—but the approach depends on whether others have pulled that commit yet. When Rewriting Is Safe Only amend and force-push if: You’re the only one using the repository You’re absolutely certain no one else has pulled the commit yet Your branch protection rules…
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:…
Flash support ended in December 2020, and Adobe no longer distributes Flash Player. Most browsers dropped Flash entirely. If you’re stuck with legacy .swf files, here’s what actually works. Ruffle: Your Best Option Ruffle is the go-to solution. It’s an open-source Flash emulator written in Rust that handles most SWF files without needing Adobe’s player….
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…
The sort command’s -n flag only handles decimal numbers. When you apply it to hexadecimal values, it falls back to lexicographic (alphabetical) sorting, which produces incorrect results since hex digits don’t follow numeric order alphabetically. Given a file with hex addresses: 400000000 __crt0 400000039 __newr0 400001B14 get_my_task_id 200000020 reg1 20400001000 status Running sort -n will…
GDM (GNOME Display Manager) lets you control which users appear on the login screen. You have two main options: hide the entire user list or exclude specific users while keeping the list visible for others. Disable the user list entirely The most straightforward approach is to disable user listing completely. This forces everyone to type…
The simplest way to see your commit history as a tree structure: git log –graph –oneline This produces a text-based graph showing branch relationships and merges with abbreviated commit hashes: * b5dc8b9 Merge branch ‘main’ into develop |\ | * 7514ef1 revised the README.md | * 6692428 align size to page for both shalloc and…
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…
Bash provides comparison operators for conditionals through the test command (aliased as [), the [[ ]] compound command, and the (( )) arithmetic command. Each has specific use cases and behavior differences worth understanding. String Comparisons String comparisons work with test/[ and [[ ]]: Operator Meaning -n STRING String length is nonzero (true if not…
When debugging a program or understanding what it actually touches on your filesystem, you need to see which files it opens. Two tools do this well: strace traces system calls in real time, while lsof inspects a running process without the overhead. Using strace to capture file operations The simplest approach is to run strace…
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…
IEEE requires a specific format for web citations, and BibTeX handles this cleanly with the @online entry type. Here’s how to get it right. IEEE Web Citation Format IEEE specifies this pattern for online sources: [#] Initial(s). Surname, “Title [Online]. Available: URL. Accessed: Month Day, Year.” A complete example looks like: [1] J. Jones, “Networks…
When you install a JDK on Linux, you need to configure environment variables so your shell uses the correct Java binary and build tools can locate the installation. If you have multiple Java versions installed, proper configuration becomes essential. Why Set Java Environment Variables Setting JAVA_HOME and PATH ensures: Tools and applications can locate the…
MPlayer is largely obsolete, but if you’re maintaining legacy systems, you’ll need to know how to position windows. For new work, use mpv (MPlayer’s maintained fork) instead. Centering with MPlayer Add this to ~/.mplayer/config: geometry=50%:50% This centers the window by setting both X and Y to 50% of screen dimensions. Override at runtime: mplayer -geometry…
MPlayer is effectively unmaintained. If you’re starting fresh, use mpv — the actively maintained fork with better codec support, hardware acceleration, and improved filter performance. That said, if you’re working with existing MPlayer setups, you can still improve playback quality through filters. When to Use Filters vs. When to Switch Before spending time tuning MPlayer,…
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…
To toggle between Simplified Chinese and Traditional Chinese input modes in ibus-libpinyin, press Ctrl+Shift+F. This shortcut has been the standard method since ibus-pinyin 1.3.7 and works across modern versions. Common ibus-libpinyin Shortcuts Beyond script conversion, these shortcuts handle daily input tasks: Shortcut Function Ctrl+Shift+F Toggle Simplified/Traditional Chinese Ctrl+. Toggle full-width/half-width punctuation Ctrl+, Toggle English/Chinese punctuation…