Log Level Detection Regex for PHP

What this pattern does

This page provides a well-structured, multi-part regular expression for matching log level detection, ported and verified for PHP. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

<?php
// Log Level Detection
// ReDoS-safe | RegexVault — Dev & Systems > Log Parsing

define('LOG_LEVEL_DETECTION_PATTERN', '/\b(TRACE|DEBUG|INFO|WARN(?:ING)?|ERROR|FATAL|CRITICAL|NOTICE|SEVERE)\b/');

function validate_log_level_detection(string $input): bool {
    return (bool) preg_match(LOG_LEVEL_DETECTION_PATTERN, $input);
}

// Example
var_dump(validate_log_level_detection("INFO: server started")); // bool(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 PHP developers because especially relevant in PHP where PCRE backtracking limits can trigger silent failures on malicious input. 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

The \b word boundaries prevent partial matches (INFORMATION matching as INFO). Capture group 1 contains the matched level. Normalize to a canonical set for cross-framework analysis.