log4j-pattern-to-regex-converter

Log4j Pattern to Regex Converter — Steady developer demand from Java devs and DevOps engineers needing to parse legacy Log4j/Logback log formats into SIEMs, Logstash, or custom regex parsers.

Zero dependencies. Pure functions, no I/O, no DOM. Runs in Node and in the browser unchanged.

Try it without installing anything: https://owaiskhan.website/tools/log4j-pattern-to-regex-converter/

Install

npm install log4j-pattern-to-regex-converter

Use

import { log4jPatternToRegexConverter } from 'log4j-pattern-to-regex-converter';

const result = log4jPatternToRegexConverter(input);
console.log(result);

API

function tokenize(pattern)

tokenize(pattern) Splits a Log4j pattern string into an array of tokens.

function patternToRegex(pattern, named)

patternToRegex(pattern, named) Converts a Log4j pattern to a regex string.

function patternToGrok(pattern)

patternToGrok(pattern) Converts a Log4j pattern to a Logstash Grok pattern string.

function testLogLine(pattern, logLine)

testLogLine(pattern, logLine) Tests a log line against the generated named-group regex.

function convert(pattern, format)

convert(pattern, format) Main entry point. Converts a Log4j pattern to the requested output format.

function log4jPatternToRegexConverter(pattern, format)

log4jPatternToRegexConverter(pattern, format) Primary named export / entry point for the tool.

const PRESETS

PRESETS — common Log4j/Logback layout patterns. Each entry has { name: string, pattern: string }.

Why this exists

The hosted version at https://owaiskhan.website/tools/log4j-pattern-to-regex-converter/ runs this exact module in the browser — the page and the package cannot disagree, because there is one implementation. Nothing you paste into the hosted tool leaves your browser.

Keywords

log4j pattern to regex converter · log4j pattern to regex online · log4j pattern to grok pattern converter · logback pattern to regex · convert log4j layout pattern to regex · log4j pattern layout regex generator

License

MIT © Owais Khan