Khaliport

Get a free TCP or UDP port on your system, works on both Nodejs and Bare runtime.

Install

npm i khaliport

Usage

import { freePort } from 'khaliport'
const port = await freePort()
console.log(port)

CLI

Install

npm i khaliport -g

Usage

khaliport

API

const port = await freePort()

Resolves with a free TCP port. The port is found by listening on port 0 (all interfaces, dual-stack where supported) and closing the server once the OS has assigned a port. Rejects if the server fails to listen.

const port = await freePortUDP()

Resolves with a free UDP port. Same approach as freePort, but binds an IPv4 (udp4) socket. Rejects if the socket fails to bind.

[!NOTE] The port is free at the moment it is returned, but nothing reserves it. Another process may take it before you bind to it, so treat the result as a best-effort hint and handle EADDRINUSE if that matters for your use case.

LICENSE

MIT