npm command show npm config
https://docs.npmjs.com/cli/config
https://stackoverflow.com/questions/42137329/npm-config-list-environment-configs-registry
$ npm config ls -l
$ npm config list
npm
https://www.npmjs.com/package/debug
https://www.npmjs.com/package/commander
https://github.com/tj/commander.js/blob/master/Readme_zh-CN.md
https://www.npmjs.com/package/request
https://www.npmjs.com/package/async