native-stream-type

Find the native stream type, validate it for child_process use

The stdio option in child_process.spawn allows only certain types of streams. You can use this module to determine if an object is an allowed stream type.

You can use this module to validate stream arguments before passing to child_process.

Install

$ npm install --save native-stream-type

Usage

const nativeStreamType = require('native-stream-type');

nativeStreamType(process.stdin);
//=> 'tty'

API

nativeStreamType(obj)

Returns a string (pipe | tty | tcp | udp) if obj is one of the native backed stream implementations.

Returns false if obj is not one of the above native streams.

Note that udp sockets don't necessarily implement a stream interface (see "Notes" section below).

obj

Type: Stream

An object that might be a native stream implementation.

Notes

This uses the undocumented process.binding(...). At present, the Node team is avoiding deprecation, so it should be safe to use.

You are allowed to pass UDP sockets as a stdio option, even though they do not implement the stream interface. Thus, getting a truthy return value does not guarantee a stream. Passing a UDP socket will spawn without throwing an error, but I have yet to figure out how to actually transfer any data to the child process when using one. You may want to guard against non streams using is-stream.

Implementation derived from Node internals here, here, and here.

License

MIT © James Talmage