寫日誌 封裝和讀取

const fs = require('fs')
const path = require('path')

// 寫日誌
function writeLog(writeStream, log) {
    writeStream.write(log + '\n')  // 關鍵程式碼
}

// 生成 write Stream
function createWriteStream(fileName) {
    const fullFileName = path.join(__dirname, '../', '../', 'logs', fileName)
    const writeStream 
 
= fs.createWriteStream(fullFileName, {
        flags: 'a'
    })
    return writeStream
}

// 寫訪問日誌
const accessWriteStream = createWriteStream('access.log')
function access(log) {
    writeLog(accessWriteStream, log)
}

module.exports = {
    access
}

const fs = require('fs')
const path 
 
= require('path')
const readline = require('readline')

// 檔名
const fileName = path.join(__dirname, '../', '../', 'logs', 'access.log')
// 建立 read stream
const readStream = fs.createReadStream(fileName)

// 建立 readline 物件
const rl = readline.createInterface({
    input: readStream
})

let chromeNum = 0
let sum 
 
= 0

// 逐行讀取
rl.on('line', (lineData) => {
    if (!lineData) {
        return
    }

    // 記錄總行數
    sum++

    const arr = lineData.split(' -- ')
    if (arr[2] && arr[2].indexOf('Chrome') > 0) {
        // 累加 chrome 的數量
        chromeNum++
    }
})
// 監聽讀取完成
rl.on('close', () => {
    console.log('chrome 佔比：' + chromeNum / sum)
})

安全

sql注入:竊取資料庫內容

xss攻擊:竊取前端的cookie內容

密碼加密:保障使用者資訊保安

npm i xss --save