meteor/npm-packages/meteor-installer/config.js

const os = require('os');
const path = require('path');

const METEOR_LATEST_VERSION = '3.3.2';
const sudoUser = process.env.SUDO_USER || '';
function isRoot() {
  return process.getuid && process.getuid() === 0;
}
function isSudo() {
  return isRoot() && !!sudoUser;
}
const localAppData = process.env.LOCALAPPDATA;
const isWindows = () => os.platform() === 'win32';
const isMac = () => os.platform() === 'darwin';
const isLinux = () => os.platform() === 'linux';

let rootPath;
if (isWindows()) {
  rootPath = localAppData;
} else if (isRoot() && sudoUser) {
  rootPath = isMac() ? `/Users/${sudoUser}` : `/home/${sudoUser}`;
} else {
  if (isRoot()) {
    console.info(
      'You are running the install script as root, without SUDO. This is not recommended and should be avoided. Continuing.',
    );
  }
  rootPath = os.homedir();
}

if (isWindows() && !localAppData) {
  throw new Error('LOCALAPPDATA env var is not set.');
}

const shouldSetupExecPath = () =>
  !process.env.npm_config_ignore_meteor_setup_exec_path;

const meteorLocalFolder = '.meteor';
const meteorPath = path.resolve(rootPath, meteorLocalFolder);

module.exports = {
  METEOR_LATEST_VERSION,
  extractPath: rootPath,
  meteorPath,
  release: process.env.INSTALL_METEOR_VERSION || METEOR_LATEST_VERSION,
  rootPath,
  sudoUser,
  startedPath: path.resolve(rootPath, '.meteor-install-started.txt'),
  isWindows,
  isMac,
  isLinux,
  isRoot,
  isSudo,
  shouldSetupExecPath,
};