nodejs问题

1. yarn add express-generator global
   然后再express myapp报错bash: express: command not found
   npm install express-generator -g 然后express myapp就没问题
   2.express框架，每次修改代码之后，都需要重新npm start 才能看到改动的效果
   安装nodemon，node.js应用有任何改动自动重启服务，
   文档：https://github.com/remy/nodemon
   npm install -g nodemon或npm install --save-dev nodemon
   运行 nodemon --exec npm start

配置nodemon.json

{
    "restartable": "rs",
    "ignore": [
        ".git",
        "node_modules/**/node_modules"
    ],
    "delay": "1500",
    "verbose": true,
    "execMap": {
        "js": "node --harmony"
    },
    "events": {
        "restart": "osascript -e 'display notification \"App restarted due to:\n'$FILENAME'\" with title \"nodemon\"'"
    },
    "watch": [
    ],
    "env": {
        "NODE_ENV": "development"
    },
    "ext": "js,json"
}