npm-nodejs包管理器

npm — node package manager

全局安装nodejs包

npm -g install net-ping

查看已经安装的nodejs应用

npm ls -g installed

创建项目过程，首先创建一个目录 mvc-express ，进入后输入

 npm init

回答一些问题创建项目

This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sane defaults.

See `npm help json` for definitive documentation on these fields
and exactly what they do.

Use `npm install  --save` afterwards to install a package and
save it as a dependency in the package.json file.

Press ^C at any time to quit.
name: (mvc-express) 
version: (0.0.0) 0.0.1
description: my try of express
entry point: (app.js) 
test command: npm test
git repository: 
keywords: 
author: jpuyy
license: (ISC) 
About to write to /private/var/forge/node/mvc-express/package.json:

{
  "name": "mvc-express",
  "version": "0.0.1",
  "description": "my try of express",
  "main": "app.js",
  "scripts": {
    "test": "npm test"
  },
  "author": "jpuyy",
  "license": "ISC"
}


Is this ok? (yes) yes

接下来我要安装一些包时，使用 npm install –save ，会自动加入到 package.json 中

npm install express --save

清理缓存
npm cache clean

检查
npm audit fix