$ npm install pm2 -g     # 命令行安装 pm2 
$ pm2 start app.js -i 4  # 后台运行pm2，启动4个app.js 
                         # 也可以把'max' 参数传递给 start
                         # 正确的进程数目依赖于Cpu的核心数目
$ pm2 start app.js --name my-api # 命名进程
$ pm2 list               # 显示所有进程状态
$ pm2 monit              # 监视所有进程
$ pm2 logs               # 显示所有进程日志
$ pm2 stop all           # 停止所有进程
$ pm2 restart all        # 重启所有进程
$ pm2 reload all         # 0 秒停机重载进程 (用于 NETWORKED 进程)
$ pm2 stop 0             # 停止指定的进程
$ pm2 restart 0          # 重启指定的进程
$ pm2 startup            # 产生 init 脚本 保持进程活着
$ pm2 web                # 运行健壮的 computer API endpoint (http://localhost:9615)
$ pm2 delete 0           # 杀死指定的进程
$ pm2 delete all         # 杀死全部进程

update test    
set 字段1=case 
when 条件1 then 值1    
when 条件2 then 值2    
end  

UPDATE group_user SET unread = CASE 
WHEN is_enter =1 THEN 0 
WHEN is_enter =0 THEN unread +1 END 
WHERE group_id =6

SELECT
CASE
WHEN price IS NULL THEN 'Not yet priced'
WHEN price < 10 THEN 'Very Reasonable Title'
WHEN price >= 10 and price < 20 THEN 'Coffee Table Title'
ELSE 'Expensive book!'
END AS "Price Category",
CONVERT(varchar(20), title) AS "Shortened Title"
FROM pubs.dbo.titles
ORDER BY price

SELECT au_fname, au_lname,
   CASE state
      WHEN 'CA' THEN 'California'
      WHEN 'KS' THEN 'Kansas'
      WHEN 'TN' THEN 'Tennessee'
      WHEN 'OR' THEN 'Oregon'
      WHEN 'MI' THEN 'Michigan'
      WHEN 'IN' THEN 'Indiana'
      WHEN 'MD' THEN 'Maryland'
      WHEN 'UT' THEN 'Utah'
        END AS StateName
FROM pubs.dbo.authors
ORDER BY au_lname

SELECT @@GLOBAL.sql_mode;
SELECT @@SESSION.sql_mode;

set @@GLOBAL.sql_mode='';
set sql_mode ='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';

SELECT @@sql_mode;
SELECT @@GLOBAL.sql_mode;

computed: {
    ...mapGetters({
      products: 'cartProducts',
      checkoutStatus: 'checkoutStatus'
    })
}

computed: {
    ...mapGetters([
      'products',   //注意这里一定要有引号，才会自动映射
      'checkoutStatus'
    })
}

 methods: {
    ...mapMutations([
      'increment' // 映射 this.increment() 为 this.$store.commit('increment')
    ]),
    ...mapMutations({
      add: 'increment' // 映射 this.add() 为 this.$store.commit('increment')
    })
  }

  methods: {
    ...mapActions([
      'increment' // 映射 this.increment() 为 this.$store.dispatch('increment')
    ]),
    ...mapActions({
      add: 'increment' // 映射 this.add() 为 this.$store.dispatch('increment')
    })
  }

   server {
        listen       443 ssl;
        server_name  cet.lenshen.com;

        ssl_certificate /usr/local/nginx/conf/lenshen.com.crt;
        ssl_certificate_key /usr/local/nginx/conf/lenshen.com.key;

        ssl_session_cache    shared:SSL:1m;
        ssl_session_timeout  5m;

        ssl_ciphers  HIGH:!aNULL:!MD5;
        ssl_prefer_server_ciphers  on;

        location / {
           proxy_pass http://localhost:8001; #后端的web服务器
           proxy_set_header Host $host;
           proxy_set_header X-Real-IP $remote_addr;
           proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
        }
    }
   server {
        listen       443 ssl;
        server_name  qq.lenshen.com;

        ssl_certificate /usr/local/nginx/conf/lenshen.com.crt;
        ssl_certificate_key /usr/local/nginx/conf/lenshen.com.key;

        ssl_session_cache    shared:SSL:1m;
        ssl_session_timeout  5m;

        ssl_ciphers  HIGH:!aNULL:!MD5;
        ssl_prefer_server_ciphers  on;

        location / {
           proxy_pass http://localhost:8080; #后端的web服务器
           proxy_set_header Host $host;
           proxy_set_header X-Real-IP $remote_addr;
           proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
        }
    }
    server {
        listen       443 ssl;
        server_name  music.lenshen.com;

        ssl_certificate /usr/local/nginx/conf/lenshen.com.crt;
        ssl_certificate_key /usr/local/nginx/conf/lenshen.com.key;

        ssl_session_cache    shared:SSL:1m;
        ssl_session_timeout  5m;

        ssl_ciphers  HIGH:!aNULL:!MD5;
        ssl_prefer_server_ciphers  on;

        location / {
           proxy_pass http://localhost:8000; #后端的web服务器
           proxy_set_header Host $host;
           proxy_set_header X-Real-IP $remote_addr;
           proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
        }
    }

  server {  
     listen      80;  
     server_name  lenshen.com;  
     return      301 https://$server_name$request_uri;  
   }
   server {  
     listen      80;  
     server_name    qq.lenshen.com;  
     return      301 https://$server_name$request_uri;  
   }  
   server {  
     listen      80;  
     server_name    music.lenshen.com;  
     return      301 https://$server_name$request_uri;  
   }     
   server {  
     listen      80;  
     server_name    cet.lenshen.com;  
     return      301 https://$server_name$request_uri;  
   }     

var app = require('express')();
var fs = require('fs');
var https = require('https');
var privateKey  = fs.readFileSync('/usr/local/nginx/conf/lenshen.com.key', 'utf8');
var certificate = fs.readFileSync('/usr/local/nginx/conf/lenshen.com.crt', 'utf8');
var credentials = {key: privateKey, cert: certificate};
var httpsServer = https.createServer(credentials, app);
var SSLPORT = 18081;
httpsServer.listen(SSLPORT, function() {
     console.log('HTTPS Server is running on: https://localhost:%s', SSLPORT);
});
// Welcome
app.get('/', function(req, res) {
     if(req.protocol === 'https') {
        res.status(200).send('Welcome to Safety Land!');
     }
     else {
        res.status(200).send('Welcome!');
     }
});

//  fs-async.js文件

import fs from 'fs'

/**
 * [读文件]
 * @param  {[type]} filePath [文件路径]
 * @return {[type]}          [description]
 */
export const readFile = (filePath) => {
	return new Promise((reslove, reject) => {
		fs.readFile(filePath, 'utf8', (err, data) => {
			if (!err) {
				reslove(JSON.parse(data))
			} else {
				reject(err)
			}
		})
	})
}

/**
 * [写文件]
 * @param  {[type]} filePath [文件路径]
 * @param  {[type]} data     [新的文件数据]
 * @return {[type]}          [description]
 */
export const writeFile = (filePath, data) => {
	return new Promise((reslove, reject) => {
		fs.writeFile(filePath, JSON.stringify(data), (err) => {
			if (err) {
				reject(err)
			}
		})
	})
}

import {readFile,writeFile} from './fs-async'
const getData=async()=>{
    const data=await readFile('./users.json')
   console.log(data)
}
getData()     //会打印出文件的内容

const arr=[{name:'zls'}]
console.log(arr.includes({name:'zls'}))   // false，注意这里是返回false

   const arr=[1]
   console.log(arr.includes(1))  // true
   const arr1=[true,false]
   console.log(arr1.includes(true))   //true
   const arr2=[undefined]
   console.log(arr2.includes(undefined))   // true
   const arr3=['str']
   console.log(arr3.includes('str'))   // true
   const arr4=[null]
   console.log(arr4.includes(null))   // true
   const arr5=[{name:'zls'}]
   console.log(arr5.includes({name:'zls'}))   // false

const index=arr.findIndex((item)=>{
   return item.name='zls'
})
//   index为0，在第0个位置，所以是存在的

import http from 'http'
import iconv from 'iconv-lite'    //引入第三方模块

const url = 'http://1212.ip138.com/ic.asp'  //获取到的会是服务器的ip地址
http.get(url, res => {
      let arrBuf = [],
      bufLength = 0
      res.on("data", chunk => {
		arrBuf.push(chunk)
		bufLength += chunk.length
      })
     .on("end", () => {
	       const chunkAll = Buffer.concat(arrBuf, bufLength),
	       strJson = iconv.decode(chunkAll, 'gb2312'), // 汉字不乱码
	       startIndex = strJson.indexOf('省'),
	       endIndex = strJson.indexOf('市'),
               city=strJson.substring(startIndex + 1, endIndex)     //城市名
               console.log(strJson,city)   //均是中文
     })
})

  //登陆后的回调
 callback({code,data,message}){ 
      if(code==1){
        socket.emit('login',data.loginStatus.userId)  // emit login事件，传递用户id
        this.$store.commit('SET_LOGIN',data)  //设置store状态
        this.$router.push('message')
      }else{
        this.$store.dispatch('setShowWarn',message)
      }
  }

    <script src="http://localhost:3000/socket.io/socket.io.js"></script>
    <script>
      const socket = io.connect('http://localhost:3000/')

      //解决用户手动刷新浏览器后，原来的socketid失效的问题
      const loginStatus= JSON.parse(localStorage.getItem("loginStatus") || '{}')
     // emit update事件，传递用户id
      loginStatus.isLogin && socket.emit('update',loginStatus.userId)   
    </script>

import socketHander from './socket'    //socket要实现的具体逻辑
//这里省略其它导入

// socket事件
io.on('connection', (socket) => {
	const socketId=socket.id
	//监听用户登录
	socket.on('login', (userId) => {
		//保存用户的id和socketid
		socketHander.saveUserSocketId(userId, socketId)
	})
	//监听用户刷新
	socket.on('update', (userId) => {
		//保存用户的id和socketid
		socketHander.saveUserSocketId(userId, socketId)
	})
})

import {
	readFile,
	writeFile
} from './fs-async'

const filePath = `${__dirname}/users.json`

// socket具体业务逻辑
export default class socketHander {
	/**
	 * [saveUserSocketId 保存用户的id和socketid]
	 * @param  {[type]} userId   [用户id]
	 * @param  {[type]} socketId [用户的socketid]
	 * @return {[type]}          [description]
	 */
	static async saveUserSocketId(userId, socketId) {
		let data = await readFile(filePath).catch((err) => {
			console.log(err)
		})
		data[userId] = socketId
		writeFile(filePath, data)
	}
}

import fs from 'fs'

/**
 * [读取文件的内容]
 * @param  {[type]} filePath [文件路径]
 * @return {[type]}          [description]
 */
export const readFile = (filePath) => {
	return new Promise((reslove, reject) => {
		fs.readFile(filePath, 'utf8', (err, data) => {
			if (!err) {
				reslove(JSON.parse(data))
			} else {
				reject(err)
			}
		})
	})
}

/**
 * [写文件]
 * @param  {[type]} filePath [文件路径]
 * @param  {[type]} data     [新的文件数据]
 * @return {[type]}          [description]
 */
export const writeFile = (filePath, data) => {
	return new Promise((reslove, reject) => {
		fs.writeFile(filePath, JSON.stringify(data), (err) => {
			if (err) {
				reject(err)
			}
		})
	})
}

{}

 //通过socket来更新消息
 updateBySocket(){
      socket.removeAllListeners()  //一定要先移除原来的事件，否则会有重复的监听器

      socket.on('receivePrivateMessage',(data)=>{
          this.$store.commit('UPDATE_MESSAGE',{
            from_user:data.from_user_beizhu,
            id:data.from_user,
            imgUrl:data.from_user_face,
            message:data.message,
            time:data.time,
            type:'single'
          })
      })
      socket.on('receiveGroupMessage',(data)=>{
          //如果不包含自己，则直接丢弃这个socket消息
          if(!data.group_member.includes(this.userId-0))  return

          this.$store.commit('UPDATE_MESSAGE',{
            from_user:data.group_name,
            id:data.group_id,
            imgUrl:data.group_avator,
            message:`${data.from_user_nick_name}:${data.message}`,
            time:data.time,
            type:'group'
          })
      })
 }

  location / {
           proxy_pass http://localhost:8080; #后端的web服务器
           proxy_set_header Host $host;
           proxy_set_header X-Real-IP $remote_addr;
           proxy_set_header REMOTE-HOST $remote_addr;
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }

        overflow:hidden;  /*内容超出后隐藏*/
        text-overflow:ellipsis; /*当文本溢出时显示省略标记(...)*/
        white-space:nowrap;  /*文本不换行*/

word-wrap:break-word;
word-break:break-all;

require("babel-core/register")({
  presets: ['es2015', 'stage-0']
})
require("babel-polyfill")

import express from 'express'
import loginRouter from './router/login'
import registerRouter from './router/register'
import friendRouter from './router/friend'
import messageRouter from './router/message'
import userRouter from './router/user'
import chatRouter from './router/chat'

const apiRouter = express.Router()

apiRouter
	.use('/login', loginRouter)
	.use('/register', registerRouter)
	.use('/friend', friendRouter)
	.use('/message', messageRouter)
	.use('/user', userRouter)
	.use('/chat', chatRouter)

export default apiRouter

[1,2,3,1,'a',1,'a'].filter(function(ele,index,array){
    return index===array.indexOf(ele)
})

allMessage.sort((prev, current) => { //按时间降序排列
        return prev.time <  current.time
 })

allMessage.sort((prev, current) => { //按时间降序排列
        return current.time - prev.time
 })