Restore a deleted or removed file in Git and undo a staged deletion without committing, using the index and git checkout -- correctly.

LoadError occurs when a Ruby gem is required outside Gemfile or .gemspec; adding its install path to $: allows temporary loading for debugging.

Resolve Git merge conflicts locally in RubyMine with a visual three-pane tool for comparing versions and choosing changes.

Use an iPhone’s cellular data connection on Ubuntu over USB by installing iPhone tethering packages and enabling Personal Hotspot.

iOS blocks dragging an iframe inside a scrollable container from moving the parent scroll area. -webkit-overflow-scrolling: touch restores touch scrolling and momentum.

Missing image requests in development can hit Rails controllers and slow pages with many broken references. A route can return an instant empty 404 for absent JPG, PNG, and GIF files.

Convert PNG, JPEG or GIF files into base64 data URIs for use in HTML, CSS, or as plain text.

Send raw HTTP or HTTPS requests from the command line when curl is unavailable or unsuitable, using nc, telnet, or openssl s_client.

Enable Sentry reporting in development to verify setup changes, using Raven and temporary test messages while avoiding committed debugging noise.

identify -verbose prints detailed image metadata from the Linux command line, useful for inspecting EXIF data and diagnosing corrupted tags.

iOS Safari can enlarge text in landscape mode and disrupt precise CSS layouts. -webkit-text-size-adjust: 100% disables the font scaling.

Open vim in read-only mode to avoid accidental edits and mistaken writes when viewing files, especially among similar filenames.

Generate barcodes and QR codes in Ruby with Barby, including PNG, data URLs, and crisp SVG output for printing and scaling.

Automating rebasing workflows reduces manual history editing when a fix must be folded into an earlier commit already in history.

Internet Explorer support depends on the Windows version, and older IE releases stop receiving security fixes once a newer supported version is available.

Default Rails generators create different combinations of models, controllers, migrations, routes, views, and tests, helping choose the right generator from the command line.

Positioning elements in JavaScript depends on window-relative and document-relative coordinates; mixing them causes misplaced layouts and incorrect measurements.

SASS mixin for fluid calc() sizing between two breakpoints, letting padding, margin, or height scale proportionally instead of stepping.

Unordered crontabs are hard to scan; sorting scheduled rows by time makes recurring jobs easier to read, including @reboot entries.

Commercial Ruby distributions for enterprises and smaller teams add secure builds, technical support, updates, and IP indemnification for business applications.

postMessage enables cross-origin data exchange, but careless use can create client-side security vulnerabilities and make origin handling error-prone.