npm install 原理
https://docs.npmjs.com/about-npm/
npm consists of three distinct components:
the website
the Command Line Interface (CLI)
the registry
https://docs.npmjs.com/downloading-and-installing-node-js-and-npm
https://github.com/workshopper/how-to-npm
https://www.npmjs.com/package/how-to-npm
https://docs.npmjs.com/cli/install#limitations-of-npms-install-algorithm
https://docs.npmjs.com/cli/install#algorithm
https://docs.npmjs.com/files/folders
$ tree -d
$ npm ls
https://www.zhihu.com/question/66629910
https://www.bbsmax.com/A/qVdemmnEdP/