tr Ref — Libor Benes (Dr. B)

tr Ref is a lightweight Firefox sidebar extension offering efficient offline access to 143 essential tr command options, character sets, translation patterns, and practical usage scenarios.

The tr command, written by Douglas McIlroy at Bell Labs in November 1973, was introduced in Version 4 Unix. It is an abbreviation of translate or transliterate, indicating its operation of replacing or removing specific characters in its input data set. It excels at single-character transformations where full string processing isn't required, offering superior performance and simplicity compared to tools like sed for character-level operations. tr's design embodies the Unix philosophy of creating focused, composable tools that do one thing well.

Content Coverage:
The extension includes essential tr elements:
• Character Translation: Map characters between sets, case conversion, ROT13 encoding.
• Character Classes: POSIX classes ([:digit:], [:alpha:], [:space:], etc.) for pattern matching.
• Deletion Operations: Remove specific characters or character classes (-d option).
• Squeeze Operations: Collapse repeated characters into single occurrences (-s option).
• Complement Operations: Invert character sets for negative matching (-c option).
• Special Characters: Handling newlines, tabs, carriage returns, and escape sequences.
• Combination Patterns: Multi-step transformations and pipelines with other Unix utilities.

Target Audience:
• System Administrators normalizing logs and text data.
• Data Analysts cleaning and preprocessing text datasets.
• Developers handling character encoding and text transformations.
• Shell Scripting Enthusiasts building text processing pipelines.
• DevOps Engineers processing system outputs and configurations.

Use Cases & Practical Applications:
• Text Normalization: Converting case, removing extra whitespace, standardizing line endings.
• Data Cleaning: Stripping punctuation, removing control characters, extracting specific character types.
• Encoding Conversion: Windows/Unix/Mac line ending conversion, ROT13 encoding/decoding.
• Log Processing: Normalizing log file formats, removing unwanted characters.
• Shell Scripting: Building text transformation pipelines in automation scripts.
• Quick Text Manipulation: Ad-hoc character replacements during development and debugging.

Extension Features:
• 143 Comprehensive Entries: Covering all tr options, character classes, and practical patterns.
• Instant Search: Real-time filtering by option, character class, or description.
• Click-to-Copy: One-click command copying for immediate terminal use.
• Compact Interface: Space-efficient sidebar optimized for quick reference during terminal work.

Security-First Design:
• Zero permissions required.
• No data collection or tracking.
• Entirely offline operation.
• Secure DOM manipulation only.
• No third-party dependencies.
• All data stored locally in embedded JavaScript file.
• Local Processing Only: All operations occur within the sidebar with no external calls.
• Secure Implementation: No use of risky features.
• Manifest v2 Compliant: Adheres to Mozilla's security standards and privacy requirements.

Technical Specifications:
• Compatibility: Firefox 109.0+ (64-bit desktop).
• Size: 25 KB total (minimal memory and storage footprint).
• Performance: Instant search response with efficient filtering algorithms.
• Testing: Verified on Firefox 147.0.2 (February 2026).

tr Ref provides immediate access to this essential utility's capabilities, supporting professionals who rely on Unix text processing tools for character-level transformations while maintaining strict security and privacy standards. The extension continues the Unix tradition of powerful, focused tools by delivering tr reference information efficiently within the browser environment.