Regex

What This Skill Does

The Regex skill is a powerful utility designed to assist users in crafting, debugging, and optimizing regular expressions across a variety of programming languages and engine types. Whether you are performing complex text extraction, validating user inputs, or refactoring legacy data, this skill acts as your expert consultant. It understands the nuances between different regex dialects—such as PCRE, Python’s re module, JavaScript, and RE2 (Go)—ensuring that your patterns are not only syntactically correct but also performant.

Installation

To integrate this skill into your environment, use the OpenClaw CLI: clawhub install openclaw/skills/skills/ivangdavila/regex

Use Cases

• Log Parsing: Extracting specific error codes, timestamps, or IP addresses from massive, unformatted server logs.
• Data Validation: Ensuring user-provided strings conform to specific formatting requirements like email addresses, phone numbers, or complex identification codes.
• Refactoring: Replacing complicated string manipulations with concise, high-performance regex patterns.
• Performance Tuning: Identifying and fixing catastrophic backtracking issues in complex patterns to prevent regex-based Denial of Service (ReDoS) vulnerabilities.

Example Prompts

1. "I need a regex pattern to validate a password that contains at least one uppercase letter, one digit, and one special character, but avoid using catastrophic backtracking. Can you explain the pattern?"
2. "Convert this JavaScript regex to Python re syntax and explain why the lookbehind behaves differently in these two engines."
3. "Help me write a regex to extract all dates in YYYY-MM-DD format from this text, but ignore any dates that are part of a comment block starting with //."

Tips & Limitations

Regex is a double-edged sword. While highly expressive, it can become unreadable and computationally expensive if not handled correctly. Always prefer simple anchors (^ and $) to limit the search space. Avoid deep nesting, such as (a+)+, which triggers exponential complexity. Remember that many engines, like Go’s RE2, intentionally lack features like backreferences to guarantee linear-time execution, so verify your target engine's capabilities before deployment. Use non-capturing groups (?:...) whenever possible to save memory and improve readability. When working with complex data, verify your regex using online testers before implementing it in production codebases.