gulp 安装

1、gulp是基于node.js流的一个前端自动化构建工具，可以使用它构建自动化工作流程，简化我们的工作亮，让我们把重点放在功能的开发上，提供开发效率和工作质量；

安装
1、npm install gulp -g
2、gulp --version
CLI version: 2.2.0
Local version: 4.0.2
3、验证
创建gulpfile.js

var gulp= require('gulp');
gulp.task('default',function(){
    console.log("HTTP Server Started"); 
});

PS D:\sourcecode\gulp> gulp
[21:06:58] Using gulpfile D:\sourcecode\gulp\gulpfile.js
[21:06:58] Starting 'default'...
[21:06:58] The following tasks did not complete: default
[21:06:58] Did you forget to signal async completion?

Did you forget to signal async completion?

var gulp= require('gulp');
gulp.task('default',function(done){
    console.log("HTTP Server Started");
    done();
});

PS D:\sourcecode\gulp> gulp
[21:12:10] Using gulpfile D:\sourcecode\gulp\gulpfile.js
[21:12:10] Starting 'default'...
HTTP Server Started
[21:12:10] Finished 'default' after 3.95 ms