Go (RE2)

Log Level in GO

Matches standard log level keywords in log lines.

Pattern

regexGO

\b(TRACE|DEBUG|INFO|WARN|ERROR|FATAL)\b   (flags: g)

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`\b(TRACE|DEBUG|INFO|WARN|ERROR|FATAL)\b`)
	input := `[INFO] Server started. [ERROR] Connection failed.`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.