Log Level Detection Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching log level detection, ported and verified for Go. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

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

package validation

import "regexp"

var logLevelDetectionRe = regexp.MustCompile(`\b(TRACE|DEBUG|INFO|WARN(?:ING)?|ERROR|FATAL|CRITICAL|NOTICE|SEVERE)\b`)

func ValidateLogLevelDetection(s string) bool {
    return logLevelDetectionRe.MatchString(s)
}

// Example
// fmt.Println(ValidateLogLevelDetection("INFO: server started")) // 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 Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. 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.