# run-on-output *Execute tasks when CLI output patterns are detected* [![Build Status](https://img.shields.io/github/actions/workflow/status/sinedied/run-on-output/ci.yml?style=flat-square)](https://github.com/sinedied/run-on-output/actions) [![npm version](https://img.shields.io/npm/v/run-on-output?style=flat-square)](https://www.npmjs.com/package/run-on-output) [![Node.js](https://img.shields.io/badge/Node.js->=20-3c873a?style=flat-square)](https://nodejs.org) [![XO code style](https://shields.io/badge/code_style-5ed9c7?logo=xo&labelColor=gray&style=flat-square)](https://github.com/xojs/xo) [![License](https://img.shields.io/badge/License-MIT-blue?style=flat-square)](LICENSE) ⭐ If you like this project, star it on GitHub! [Features](#features) • [Installation](#installation) • [Usage](#usage) • [Examples](#examples)

A lightweight Node.js CLI tool that monitors command output in real-time and triggers actions when specific patterns are found. Perfect for automation workflows, development environments, and CI/CD pipelines. ## Features - 🎯 **Pattern Matching** - Monitor stdout/stderr for regex patterns or plain strings - ⚡ **Real-time Monitoring** - Output is forwarded in real-time while monitoring - 🔧 **Flexible Actions** - Display messages or execute commands when patterns match - 📝 **Multiple Patterns** - Wait for multiple patterns before triggering actions - 🚀 **Zero Dependencies** - Built with Node.js built-in modules only ## Installation ```bash npm install -g run-on-output ``` Or use without installing: ```bash npx run-on-output [options] [args...] ``` ## Usage ### Basic Examples **Display a message when server starts:** ```bash run-on-output -s "Server started" -m "🚀 Server is ready" npm start ``` **Execute a health check when server is listening:** ```bash run-on-output -p "listening on port \\d+" -r "curl http://localhost:3000/health" node server.js ``` **Monitor development environment startup:** ```bash run-on-output -s "webpack compiled,server ready" -m "✅ Development environment ready" npm run dev ``` **Multiple actions - show message and open browser:** ```bash run-on-output -s "ready" -m "Server is up" -r "open http://localhost:3000" npm start ``` **Run npm script when server is ready:** ```bash run-on-output -s "Server running" -n "test" node server.js ``` > [!TIP] > You can use the short alias `roo` instead of `run-on-output` for faster typing: > ```bash > roo -s "Server started" -m "🚀 Server is ready" npm start > ``` ### Command Line Options ``` run-on-output [OPTIONS] [args...] OPTIONS: -p, --patterns Comma-separated list of regex patterns to watch for -s, --strings Comma-separated list of plain strings to watch for -r, --run Command to execute after all patterns are found -n, --npm