“寓教于乐”的学习记录【玩转Node.js】

'use strict';
const nodemailer = require('nodemailer');

// async..await is not allowed in global scope, must use a wrapper
async function main() {
  let user = '实际发送人的邮箱';
  // create reusable transporter object using the default SMTP transport
  let transporter = nodemailer.createTransport({
    host: 'smtp.qq.com',
    port: 587,
    secure: false, // true for 465, false for other ports
    auth: {
      user: user, // generated ethereal user
      pass: '发送人邮箱授权码', // generated ethereal password
    },
  });

  return await transporter.sendMail({
    from: `"叶一一🐇" <${user}>`, // sender address
    to: 'xxjsds2010@163.com', // list of receivers
    subject: 'Hello World', // Subject line
    text: 'Hello World', // plain text body
    html: `你好:<b>年轻人</b>`, // html body
    attachments: [
      {
        filename: '第一个.doc',
        path: 'https://xxx.doc',
      },
    ], // Add Attachments to messages
  });
}

main().catch(console.error);

Seconds Minutes Hours DayofMonth Month DayofWeek Year或
Seconds Minutes Hours DayofMonth Month DayofWeek

const schedule = require('node-schedule');
const sendEMail = require('./sendEmail');

/**
 * 定时任务
 */
const creatSchedule = timePoint => {
  let count = 1;
  const all = schedule.scheduleJob(timePoint, () => {
    console.log('发送邮件：' + new Date());
    // 发送邮件
    sendEMail.main();
    count++;
  });
  setTimeout(() => {
    console.log('取消定时任务:' + new Date());
    all.cancel();
  }, 180000);
};

let timePoint = '10 * * * * *';
creatSchedule(timePoint);

const schedule = require('node-schedule');
const sendEMail = require('./sendEmail');

/**
 * 定时任务
 */
const creatSchedule = timePoint => {
  let count = 1;
  const all = schedule.scheduleJob(timePoint, () => {
    console.log('发送邮件：' + new Date());
    // 发送邮件
    sendEMail.main();
    count++;
  });
  setTimeout(() => {
    console.log('取消定时任务:' + new Date());
    all.cancel();
  }, 180000);
};
let timePoint = new schedule.RecurrenceRule();
timePoint.second = 11;
creatSchedule(timePoint);

const buffer = require('buffer');

// 创建长度为 10 的以零填充的缓冲区。
const buf1 = buffer.Buffer.alloc(10);

// 创建长度为 10 的缓冲区，
// 使用值为 `1` 的字节填充。
const buf2 = buffer.Buffer.alloc(10, 1);

const fs = require('fs');
const buffer = require('buffer');

/**
 * 多次读取实现文件拷贝
 * @param {string} initFile 源文件路径
 * @param {string} copyFile 目标文件路径
 * @param {number} bufSize 缓冲区的大小
 */
function copyFunc(initFile, copyFile, bufSize) {
  // 打开源文件
  fs.open(initFile, 'r', (err, readFd) => {
    // 打开目标文件
    fs.open(copyFile, 'w', (err, writeFd) => {
      let buf = buffer.Buffer.alloc(bufSize); // 创建一个空的缓冲区，大小为size的值
      let readFlag = 0; // 下次读取的源文件的位置
      let writeFlag = 0; // 下次写入的目标文件的位置

      (function next() {
        // 读取源文件
        fs.read(readFd, buf, 0, bufSize, readFlag, (err, bytesRead) => {
          readFlag += bytesRead;

          // 如果源文件没有可复制内容则关闭源文件
          if (!bytesRead) fs.close(readFd, err => console.log('拷贝完成，关闭源文件'));

          // 写入目标文件
          fs.write(writeFd, buf, 0, bytesRead, writeFlag, (err, bytesWritten) => {
            // 如果源文件没有可复制内容同步缓冲区关闭目标文件
            if (!bytesWritten) {
              fs.fsync(writeFd, err => {
                console.log('拷贝完成，同步缓存');
                fs.close(writeFd, err => {
                  console.log('拷贝完成，关闭目标文件');
                });
              });
              return; // 关闭next函数的执行
            }
            writeFlag += bytesWritten;
            // 继续读取、写入
            next();
          });
        });
      })();
    });
  });
}

// buffer 的长度
const bufSize = 20;
copyFunc('./files/init.txt', './files/copy.txt', bufSize);