Learning with Ditig

Discover Information Technology - Information and Guidance (Ditig) is an educational platform with tutorials, guides, and resources to help you learn and understand tools and technologies.

Cheat sheet

Terminal

256 colors cheat sheet

List of 256 colors for Xterm prompt (console). Contains displayed color, Xterm Name, Xterm Number (ANSI color code), HEX, RGB and HSL color codes.

Android Debug Bridge

adb cheat sheet

Cheat sheet for Android Debug Bridge (adb) commands, covering device management, file operations, logging, shell access, app management, backup, restore, and more.

Linux Package Manager

APT cheat sheet

APT command cheat sheet for Debian/Ubuntu Linux. Learn to install, remove, update, and manage packages with apt, apt-cache, and repository tools. APT command reference.

Keyboard Bindings

Ardour cheat sheet

A concise Ardour cheat sheet that lists default keyboard shortcuts and keybindings for the editor, mixer, MIDI, transport, and other windows, organized by context.

Text Processing

AWK cheat sheet

AWK cheat sheet with essential commands, syntax, variables, and examples for text processing and data extraction. Quick reference guide for using AWK.

Package Manager

Bundler cheat sheet

Cheat sheet for Bundler, the Ruby gems package manager. Learn how to install gems, manage dependencies, lock versions, and update your Ruby application's libraries.

C* Music Player

cmus cheat sheet

Comprehensive cheat sheet for using cmus, the console-based music player. Essential commands for navigation, playback, filtering, volume control, and playlist management.

Linux

Linux Package Manager

APT cheat sheet

APT command cheat sheet for Debian/Ubuntu Linux. Learn to install, remove, update, and manage packages with apt, apt-cache, and repository tools. APT command reference.

Package Management

Flatpak cheat sheet

Flatpak cheat sheet. Comprehensive Flatpak command reference grouped by task. Covers installation, updates, permissions, runtime options, repositories, and troubleshooting.

Linux Installation Guide

ThinkPad X13 Arch Linux install

Beginner friendly guide on how to install Arch Linux on a Lenovo ThinkPad X13 Gen 5 (Intel). Full process from obtaining Arch Linux to a finished installation.

Jekyll Installation Guide

Install Jekyll on Arch Linux

Jekyll on Arch Linux - Beginner friendly guide on how to install Jekyll - the static site generator - on Arch Linux using the Bash shell, RubyGems and Bundler.

Linux System Administration

How to kill a frozen Linux terminal

Learn how to terminate unresponsive Linux terminals using signals. Discover Linux signal types, how to send them, and their effects on processes.

Linux Scripting

Rename files based on pattern

Learn how to rename files in bulk on Linux using simple shell commands with Bash's parameter expansion. Includes examples and detailed command breakdowns.

Terminal Multiplexer

How to resize a tmux window

Learn how to resize and maximize a tmux window using resize-window and manual resizing options for full control over your tmux session.

Scripting

Text Processing

AWK cheat sheet

AWK cheat sheet with essential commands, syntax, variables, and examples for text processing and data extraction. Quick reference guide for using AWK.

Bash Script

Digitally frame photos with PhotoFramer

Learn how to use PhotoFramer, a Bash script that adds EXIF information, location, and camera settings as a frame to your photos without modifying originals.

Searching

GNU find cheat sheet

GNU find command cheat sheet: Search files by name, type, size, time, permissions, and more. Includes examples for deletion, batch actions, and output formatting.

Shell Scripting

How to add comments in Bash scripts

Learn how to add single-line, multi-line, and inline comments in Bash scripts, including the role of the shebang (#!) and how it is not considered a comment.

Sending HTTP POST Requests

How to make POST requests using cURL

Learn how to create HTTP POST requests with cURL using flags like --data, --form, and --request. Includes examples for JSON, XML, CSV, stdin, and multipart uploads.

Extracting HTTP Status Codes

Output HTTP status code only using cURL

Learn how to make cURL output only the numerical HTTP status code using two command-line methods, with detailed explanations of all options and dependencies.

Linux Scripting

Rename files based on pattern

Learn how to rename files in bulk on Linux using simple shell commands with Bash's parameter expansion. Includes examples and detailed command breakdowns.

Tools

Web Design

Bidirectional PX - REM converter

With our free online tool, you can easily convert pixels (px) to REM and vice versa in real time. Useful for responsive web design, CSS styling, and resizing. Fast, accurate, and free.

Text Formatting

Text case converter

Free online text case converter that transforms text between uppercase, lowercase, title case, sentence case and more. Useful for everyone who needs proper text formatting.

CSS Selectors

CSS specificity calculator

CSS specificity calculator that shows how browsers prioritize styles. Enter any selector to see its specificity score for ID, class, and type selectors.

Data Conversion

CSV to JSON converter

Online CSV to JSON converter. Convert CSV data to clean JSON in your browser with options for array, hash, or minified output. No data upload required - works entirely in your browser.

Text Sanitation

Duplicate line removal tool

Tool to remove duplicate lines from text with optional sorting. Quickly clean and organize your text by removing duplicates and sorting alphabetically, by ASCII value, or in reverse order.

Character Encoding

HTML entity encoder and decoder

Easily encode and decode HTML entities with this online tool. Supports named entities from the W3C HTML5 spec plus 106 special characters, including arrows and currency symbols.

Text Analysis

Realt-time text counter

A free online tool to analyze your text in real-time. Count words, characters, sentences, and lines. Find the longest word, track sentence length, and estimate reading time.

Email

Email Syntax

Characters allowed in email addresses

Learn which characters are allowed in email addresses, covering both the local (addressee) and domain parts, how email syntax is structured, and what the relevant technical standards say.

Email Administration

Mailbox.org custom email domain

How to add a custom domain to mailbox.org for sending and receiving emails. Incl. SPF, DMARC and DKIM to an existing mailbox.org email account. Simple step-by-step instruction.

HTML Email Links

Add a subject to email mailto link

Learn how to add subject, CC, BCC, and body fields to an email mailto link, format additional parameters, and encode special characters properly according to RFC 3986.

Email Metadata

Introduction to email headers

Learn what email headers are, how to view raw headers, and understand key fields like DomainKeys Identified Mail (DKIM) and Sender Policy Framework (SPF) for email security.

Email Security

Understanding DKIM

Learn how DomainKeys Identified Mail (DKIM) enhances email security by allowing senders to sign messages cryptographically, ensuring email integrity and authenticity.

Email Security

Understanding DMARC

Domain-based Message Authentication, Reporting & Conformance (DMARC) enhances email security and helps domain owners control how unauthenticated messages are handled.

Email Security

Understanding SPF

Learn how Sender Policy Framework (SPF) works, its mechanisms, and how to configure it for secure email authentication to help prevent email spoofing, spam, and phishing attacks.

Cmus

C* Music Player

cmus cheat sheet

Comprehensive cheat sheet for using cmus, the console-based music player. Essential commands for navigation, playback, filtering, volume control, and playlist management.

C* Music Player

How to filter music in cmus permanently

Learn how to use permanent filters in cmus using metadata like genre, title, and duration to refine your playlist permanently with fset and factivate to manage your library efficiently.

C* Music Player

How to filter music in cmus temporarily

Learn how to apply temporary filters (:filter) in cmus using metadata like genre, title, and duration to refine your playlist and how to remove filters quickly.

C* Music Player

How to create a playlist in cmus

Learn how to create, save, and manage playlists in cmus music player. This step-by-step guide covers adding songs to playlists, saving playlists, and reloading them for future use.

C* Music Player

How to install cmus

Learn how to install C* Music Player (cmus) on Linux, macOS, Windows, and BSD systems. Step-by-step instructions for package managers and compiling from source.

C* Music Player

How to stream music with cmus

Learn how to stream music with cmus, a lightweight terminal-based player. Add M3U or PLS playlist links from services like Shoutcast or Icecast for seamless streaming.

C* Music Player

How to refresh the cmus music library

Learn how to update the Cmus music library manually using commands or automate the process with a config file or custom shell script with key binding.

Vim

Vim Text Editor

Comment/uncomment multiple lines in Vim

Learn how to comment and uncomment multiple lines in Vim using visual blocks and line ranges. Examples for multiline commenting/uncommenting with and without visual selection.

Vim Text Editor

Delete to end of line in Vim

Learn how to delete from the current cursor position to the end of the line in Vim with a simple command. Improve your text editing in Vim today!

Vim Text Editor

Delete lines by pattern in Vim

Learn how to delete all lines matching specific patterns, covering multiple patterns, ranges, case-(in)sensitivity, and other advanced techniques with examples.

Vim Text Editor

Edit multiple files at once in Vim

How to edit multiple files in the buffer of the Vim text editor at once. Search and replace command examples to change and save multiple files at the same time.

Improve Focus When Editing in Vim

Vim: Highlight current line and column

Learn how to highlight the current line and column in Vim permanently or temporarily, how to customize colors, and how to prevent color scheme overwrites.

Vim Text Editor

Vim: Delete all blank lines

This guide explains how to make Vim delete all blank / empty lines or lines containing only whitespace (tabs or spaces) for efficient text cleanup. Also applies to Gvim and Neovim.

Vim Text Editor

How to highlight the current line in Vim

Learn how to highlight the current line in Vim by using settings like 'cursorline' and customizing its color through your color scheme or highlight groups.

Web development

Web Design

When to use Flexbox, when to use Grid

Learn when to use CSS Flexbox vs. Grid, with examples for each. Understand their technical differences and how to combine them for modern, responsive web design.

Web Design

:nth-child cheat sheet

The nth-child cheat sheet explains how the CSS :nth-child() pseudo-class targets elements based on their order within a parent, supporting patterns, formulas, and specificity.

Web Design

CSS selectors cheat sheet

Cheat sheet for Cascading Style Sheets (CSS) selectors and combinators. Includes specificity score. Many examples of simple, compound and complex selectors.

Insert Quotation Marks Automatically

Displaying quotes before and after quotes

Learn how to use the CSS quotes property to display quotation marks automatically or with custom string values with HTML elements like blockquote and q.

Browser Customization

Firefox config for web developers

The article provides recommended Firefox settings adjustments for enhanced user-experience, privacy, and performance, suitable for both developers and general users.

Markdown Syntax

Adding code blocks in markdown lists

Markdown code blocks in lists explained. Learn about proper indentation, correct use of triple backticks, and attention to renderer-specific quirks. Many code examples.

HTML Email Links

Add a subject to email mailto link

Learn how to add subject, CC, BCC, and body fields to an email mailto link, format additional parameters, and encode special characters properly according to RFC 3986.

Css

Web Design

When to use Flexbox, when to use Grid

Learn when to use CSS Flexbox vs. Grid, with examples for each. Understand their technical differences and how to combine them for modern, responsive web design.

Font Weight Conventions

CSS font-weight cheat sheet

Understand the CSS font-weight property with this cheat sheet covering numeric values, named keywords, browser support, fallbacks and variable fonts.

Web Design

:nth-child cheat sheet

The nth-child cheat sheet explains how the CSS :nth-child() pseudo-class targets elements based on their order within a parent, supporting patterns, formulas, and specificity.

CSS Color Scheme

CSS named colors

Comprehensive guide to all 147 CSS color keywords, including their 142 named colors. List of all CSS Color Module Level 4 named colors. Includes hex, RGB, and HSL values.

Web Design

CSS selectors cheat sheet

Cheat sheet for Cascading Style Sheets (CSS) selectors and combinators. Includes specificity score. Many examples of simple, compound and complex selectors.

CSS Selectors

CSS specificity calculator

CSS specificity calculator that shows how browsers prioritize styles. Enter any selector to see its specificity score for ID, class, and type selectors.

Insert Quotation Marks Automatically

Displaying quotes before and after quotes

Learn how to use the CSS quotes property to display quotation marks automatically or with custom string values with HTML elements like blockquote and q.

Standard

CSS Color Scheme

CSS named colors

Comprehensive guide to all 147 CSS color keywords, including their 142 named colors. List of all CSS Color Module Level 4 named colors. Includes hex, RGB, and HSL values.

Character Encoding

HTML entities cheat sheet

Complete HTML entity reference list. Includes symbols, arrows, mathematical operators, and special characters in Unicode, hex, decimal, named entity, and CSS codes.

Web Standards

HTML void elements

The concept of void elements in HTML and how they differ from self-closing tags in XML, XHTML, and SVG. Highlighting, syntax, and parsing differences.

Internet Standards

HTTP status codes

List of all Hypertext Transfer Protocol (HTTP) response status codes, the standardized, three-digit messages from servers indicating the outcome of client requests.

Date and Time on the Internet

Internet Timestamps

Guide to RFC 3339 and IXDTF timestamp formats with syntax, examples, and format specifiers. Timestamp grammar, timestamp comparisons, and practical usage.

Privacy on the Web

Introduction to Referrer Policy

Learn what the Referrer Policy is, why it matters for privacy, and how you can control it using simple directives to stay compliant and protect user data.

Web Security

Introduction to Subresource Integrity (SRI)

Subresource Integrity (SRI) secures websites by validating external resources with cryptographic hashes. Learn how to implement SRI to protect users from tampered resources for their security.

Security

Encryption Software

Difference between GPG and PGP

Learn the key differences between PGP, GPG, OpenPGP, and LibrePGP. This guide covers licensing, cost, interoperability, and platform support in detail.

Browser Customization

Firefox config for web developers

The article provides recommended Firefox settings adjustments for enhanced user-experience, privacy, and performance, suitable for both developers and general users.

Command-line Encryption for Secure Communication

GPG Cheat Sheet

A concise GNU Privacy Guard (GPG) cheat sheet covering GPG vs PGP, options, basic command, and practical examples for encryption, signing, and key management.

Privacy on the Web

Introduction to Referrer Policy

Learn what the Referrer Policy is, why it matters for privacy, and how you can control it using simple directives to stay compliant and protect user data.

Web Security

Introduction to Subresource Integrity (SRI)

Subresource Integrity (SRI) secures websites by validating external resources with cryptographic hashes. Learn how to implement SRI to protect users from tampered resources for their security.

Security Auditing

Lynis cheat sheet

A concise Lynis cheat sheet that explains common commands, scan types, options, and helpers so you can audit Linux, macOS, and UNIX systems.

Web Security

Cross-Origin Resource Sharing (CORS)

Learn how Cross-Origin Resource Sharing (CORS) works, including HTTP headers, preflight requests, and server configuration. Fix common CORS errors and secure cross-origin API access.

Html

HTML Basics

Difference between HTML tags and elements

Understand the difference between HTML tags, elements, and tag names to communicate more precisely about HTML structure and meaning when working with others.

Web Standards

How to insert spaces in HTML

Learn how to insert empty spaces in HTML using entities, `pre`, `code`, CSS properties `word-spacing` and `letter-spacing`, CSS inline styles, and JavaScript solutions.

Character Encoding

HTML entity encoder and decoder

Easily encode and decode HTML entities with this online tool. Supports named entities from the W3C HTML5 spec plus 106 special characters, including arrows and currency symbols.

Character Encoding

HTML entities cheat sheet

Complete HTML entity reference list. Includes symbols, arrows, mathematical operators, and special characters in Unicode, hex, decimal, named entity, and CSS codes.

Web Standards

HTML void elements

The concept of void elements in HTML and how they differ from self-closing tags in XML, XHTML, and SVG. Highlighting, syntax, and parsing differences.

List Styles

HTML ordered lists

Learn about ordered lists (ol) in HTML and how to customize their numbering styles using the type attribute, including numbers, letters, and Roman numerals.

Responsive Web Design

How to create a responsive 100% width table

Learn multiple methods to create fully responsive tables with 100% width using CSS and HTML only, including practical code examples for flexible and overflow-based solutions.

Bash

Bash Script

Digitally frame photos with PhotoFramer

Learn how to use PhotoFramer, a Bash script that adds EXIF information, location, and camera settings as a frame to your photos without modifying originals.

Shell Scripting

Latest publications

Random Quote

“I do hope and expect to be able to find a job much more easily due to Linux.”

Linus Torvalds Finnish software engineer, creator of the Linux kernel and GitLinux Journal, 1994 - IT quotes