The process.stdout property returns a stream connected tostdout (fd 1). It is a net.Socket (which is a Duplex stream) unless fd 1 refers to a file, in which case it is a Writable stream.

For example, to copy process.stdin to process.stdout:

import { stdin, stdout } from 'node:process';

stdin.pipe(stdout);

process.stdout differs from other Node.js streams in important ways. See note on process I/O for more information.