Log File Path Extraction Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching log file path extraction, ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// Log File Path Extraction
// ReDoS-safe | RegexVault — Dev & Systems > Log Parsing

const logFilePathExtractionRegex = /^\\/(?:[^\\/\s]+\\/)*[^\\/\s]+$/g;

function validateLogFilePathExtraction(input: string): boolean {
  return logFilePathExtractionRegex.test(input);
}

// Example
console.log(validateLogFilePathExtraction("/var/log/app.log")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Log Parsing category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Group 1 = matched path. Spaces in paths are not matched. URLs (http://host/path) may partially match since /path is valid — filter by context after extraction.