redirect-stdio

Utilities for redirecting node process stdout and stderr.

Note: Only works on MacOS and Linux.

Motivation

Imagine you have a node app that logs to stdout and a bash script that runs your node process like this:

node myapp.js >> access.log

Later, you want to add logrotate, which moves access.log to access.log.2 and then calls SIGUSR2 on your node process. But your node process is logging to stdout, and can't exactly "reopen" process.stdout.

With redirect-stio, you can:

• use pathFromFd to find where your process's stdout is actually going
• on SIGUSR2, re-open the log path you just found, and write that file descriptor over the old one to rotate logs

Usage

const { reopenStdout, reopenStderr } = require('redirect-stdio');

process.on('SIGUSR2', function() {
  reopenStdout();
  reopenStderr();
});

License

Copyright 2023 Movable, Inc. See LICENSE.md.