安装

linux

curl --silent --location https://rpm.nodesource.com/setup_5.x | bash -
curl -sL https://rpm.nodesource.com/setup_10.x | bash -
yum -y install nodejs

mac

brew install node

模块

全局环境配置

• window
  • npm config set prefix "D:\Program Files\nodejs\node_global"
  • npm config set cache "D:\Program Files\nodejs\node_cache"
  • PATH D:\Program Files\nodejs\node_global\
• Mac
  • sudo npm config set prefix "/usr/local/node_global"
  • sudo npm config set cache "/usr/local/node_cache"

命令

• 查看版本 npm -v
• npm升级 npm install npm -g
• npm安装模块 npm install <module_name> -g
• npm卸载模块 npm uninstall <module_name>
• npm更新模块 npm update <module_name>
• npm查看模块 npm list -g
• npm搜索模块 npm search <module_name>
• 安装淘宝镜像 npm install -g cnpm --registry=https://registry.npm.taobao.org
• 安装style-loade npm install style-loader css-loader --save-dev
• 清空缓存 npm cache clean --force
• 校验缓存 npm cache verify

语法

安装

* node版本 `node -v`
* npm版本 ` npm -v`
* 查看node安装位置 `where node`
* 安装淘宝镜像 npm install -g cnpm --registry=https://registry.npm.taobao.org`
* 查看文件夹下安装的模块 `npm list --depth=0`
* 查看全局安装的模块 `npm list --depth=0 -global`
* 安装模块 `npm install xxx`
* 安装全局模块 `npm install -g xxx`
* 卸载模块 `npm uninstall xxx`
* 卸载全局模块 `npm uninstall -g xxx`
* 设置本地仓库 `npm config set prefix "D:\Program Files\nodejs\node_global"``
* 设置缓存 `npm config set cache "D:\Program Files\nodejs\node_cache"``
* 查看镜像站点 `npm config get registry`
* 启动服务 `npm run serve`

Hello World

var http = require("http");
http.createServer(function(request, response) {
response.writeHead(200, {'Content-Type': 'text/plain'});
response.end('Hello World\n');
}).listen(8888);
console.log("Service run at http://127.0.0.1:8888")

交互解释器（REPL）

• 计算
• 属性
• 方法
• 回调函数
• 阻塞实例

var fs = require("fs");
var data = fs.readFileSync('input.txt');
console.log(data.toString());
console.log('程序执行结束');

• 非阻塞实例

var fs = require('fs');
fs.readFile('input.txt', function(err, data) {
    if (err) {
        console.error(err)
    } else {
        console.log(data.toString());
    }
});
console.log('程序执行结束');

事件

* 循环 `观察者模式 `事件相当于主题 事件处理函数相当于观察者
* EventMitter对象
    * 实例
    ```
    // 事件模块对象
    var events = require('events');
    // 事件处理对象
    var eventEmitter = new events.EventEmitter();
    // 连接函数
    var connectHandler = function connected() {
    console.log('连接成功');
    eventEmitter.emit('dataReceived');
    }
    // 注册连接函数
    eventEmitter.on('connection', connectHandler);
    // 注册完成匿名函数
    eventEmitter.on('dataReceived', function() {
    console.log('数据接受成功');
    });
    // 触发连接
    eventEmitter.emit('connection');
    // 完成
    console.log('程序执行完毕');
    ```

缓冲区 Buffer

* 用途 `处理二进制数据
* 创建
    ```
    const buf = Buffer.alloc(10);
    console.log(buf);
    const buf = Buffer.from('wings', 'ascii');
    console.log(buf.toString('hex'));
    ```
* 写入
    ```
    const buf = Buffer.alloc(10);
    const len = buf.write('www.baidu.com');
    console.log('写入字节数' + len);
    ```
* 读取
    ```
    for (let i = 0; i < 5; i++) {
        console.log(buf[i]);
    }
    ```
* 转JSON
    ```
    const buf = Buffer.alloc(10);
    const json = buf.toJSON();
    console.log(json);
    ```
* 合并
    ```
    const buf1 = Buffer.from('Hello');
    const buf2 = Buffer.from('World');
    const buf3 = Buffer.concat([buf1, buf2]);
    console.log(buf3.toString());
    ```
* 比较
    ```
    const buf1 = Buffer.from('Hello');
    const buf2 = Buffer.from('2Hello3');
    var result = buf1.compare(buf2);
    if (result < 0) {
    console.log('之前');
    } else if (result == 0) {
    console.log('相等');
    } else {
    console.log('之后');
    }
    ```
* 拷贝
    ```
    const buf1 = Buffer.from('Hello');
    const buf2 = Buffer.from('1234567890');
    buf1.copy(buf2, 2);
    console.log(buf2.toString());
    ```
* 裁剪
    ```
    const buf1 = Buffer.from('Hello');
    const buf2 = buf1.slice(0, 3);
    console.log(buf2.toString());
    ```
* 长度
    ```
    const buf = Buffer.from('Hello');
    console.log(buf.length);
    ```

流 Stream

* 流读取
    ```
    var fs = require('fs');
    var data = '';
    // 创建流
    var readStream = fs.createReadStream('input.txt');
    // 设置编码
    readStream.setEncoding('UTF8');
    // 流事件 data end err
    readStream.on('data', function(chunk) {
    data += chunk;
    });
    readStream.on('end', function() {
    console.log(data);
    });
    readStream.on('error', function(err) {
    console.log(err);
    });
    console.log('程序执行完毕');
    ```
* 写入流
    ```
    var fs = require('fs');
    var data = '我就是我';
    // 创建
    var writeStream = fs.createWriteStream('output.txt');
    // 写入
    writeStream.write( data, 'UTF8');
    writeStream.end();
    // 写入流事件监听
    writeStream.on('finish', function() {
    console.log('写入完成');
    });
    writeStream.on('error', function(err) {
    console.log(err.stack);
    });
    console.log('程序执行完毕');
    ```
* 管理流
    ```
    var fs = require('fs');
    var readStream = fs.createReadStream('input.txt');
    var writeStream = fs.createWriteStream('output.txt');
    readStream.pipe(writeStream);
    console.log('程序执行完毕');
    ```
* 链式流
    ```
    * 压缩
    var fs = require('fs');
    var zlib = require('zlib');
    fs.createReadStream('input.txt').pipe(zlib.createGzip()).pipe(fs.createWriteStream('input.txt.gz'));
    console.log('程序执行完成');
    * 解压
    var fs = require('fs');
    var zlib = require('zlib');
    fs.createReadStream('input.txt.gz').pipe(zlib.createGunzip()).pipe(fs.createWriteStream('input2.txt'));
    console.log('程序执行完毕');
    ```

模块

* 方法模块
    * 定义
    ```
    exports.world = function() {
        console.log('Hello World');
    }
    ```
    * 引用
    ```
    var hello = require('./hello.js');
    hello.world();
    ```
* 对象模块
    * 定义
    ```
    function Hello() {
    var name;
    this.setName = function (newname) {
    this.name = newname
    };
    this.sayHello = function() {
    console.log('hello ' + this.name);
    }
    };
    module.exports = Hello;
    ```
    * 引用
    ```
    var Hello = require('./hello.js');
    var hello = new Hello();
    hello.setName('Wings');
    hello.sayHello();
    ```
* 原生模块
    * 网络 `http`
    * 路由 `url`
    * 文件 `fs`

函数

* 匿名函数参数实例
    ```
    function say(name) {
    console.log('hello' + name);
    }
    // 接受匿名函数参数
    function execure(someFunction, name) {
    someFunction(name);
    }
    execure(say, 'Wings');
    ```

路由

* 服务器
    ```
    var http = require('http');
    var url = require('url');
    function start(route) {
    function onRequest(request, response) {
    var pathname = url.parse(request.url).pathname;
    route(pathname);
    response.writeHead(200, {'Content-Type':'text/plain'});
    response.write('Hello World');
    response.end();
    }
    http.createServer(onRequest).listen(8888);
    console.log('Server has started.');
    }
    exports.start = start;
    ```
* 路由
    ```
    function route(pathname) {
    console.log(pathname);
    }
    exports.route = route;
    ```
* 启用
    ```
    var server = require('./server');
    var router = require('./router');
    server.start(router.route);
    ```

全局变量

* 文件名
    ```
    console.log(__filename);
    ```
* 目录
    ```
    console.log(__dirname);
    ```
* 延时执行
    ```
    function sayHello () {
    console.log('hello');
    }
    var t = setTimeout(sayHello, 2000);
    clearTimeout(t);
    ```
* 定时器
    ```
    function sayHello () {
    console.log('hello');
    }
    var t = setInterval(sayHello, 2000);
    clearInterval(t);
    ```
* 控制台
    ```
    console.log('Hello World');
    ```
* 进程
    ```
    process.on('exit', function(code){
    console.log('退出码' + code);
    });
    console.log('程序执行结束');
    ```

常用工具

* 文件系统（fs）
* 读取文件同步 `fs.readFileSync(path)
* 读取文件异步 `fs.readFile(path, callback) fs.read(fd, buffer, offset, length, position, callback)
* 打开文件 `fs.open(path, r+, callback)
* 获取文件信息 `fs.stat(path, callback)
* 写入文件 `fs.writeFile(file, data, callback)
* 关闭文件 `fs.close(fd, callback)
* 截取文件 `fs.ftruncate(fd, len, callback)
* 删除文件 `fs.unlink(path, callback)
* 创建目录 `fs.mkdir(path, callback)
* 读取目录 `fs.readir(path, callback)
* 删除目录 `fs.rmdir(path, callback)
* GET\POST请求
* Web模块
* Express模块
* RESTful
* 多线程