PS H:\Vue代码\day6\02.webpack-vue1> npm run dev

> 02.webpack-vue1@1.0.0 dev H:\Vue代码\day6\02.webpack-vue1
> webpack-dev-server --open --port 3000 --contentBase src --hot

internal/modules/cjs/loader.js:584
    throw err;
    ^

Error: Cannot find module 'unpipe'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:582:15)
    at Function.Module._load (internal/modules/cjs/loader.js:508:25)
    at Module.require (internal/modules/cjs/loader.js:637:17)
    at require (internal/modules/cjs/helpers.js:22:18)
    at Object.<anonymous> (H:\Vue代码\day6\02.webpack-vue1\node_modules\_finalhandler@1.1.2@finalhandler\index.js:20:14)
    at Module._compile (internal/modules/cjs/loader.js:701:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:712:10)
    at Module.load (internal/modules/cjs/loader.js:600:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:539:12)
    at Function.Module._load (internal/modules/cjs/loader.js:531:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! 02.webpack-vue1@1.0.0 dev: `webpack-dev-server --open --port 3000 --contentBase src --hot`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the 02.webpack-vue1@1.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     D:\可视化内容软件\nodejs\node_cache\_logs\2019-11-30T12_09_26_238Z-debug.log

错误信息如上，一开始报的错误是

'webpack-dev-server' is not recognized as an internal or external command,

我还纳闷，不是安装过webpack-dev-server么，为何不识别，然后我又安装一遍发现报的就是上面这个584错误，解决方法如下：
1、强制永久删除node_modules文件夹，只是点删除就说需要管理员权限

2、输入命令 npm install即可