npm installation always goes wrong, and then I delete the webpack-cli folder in node_modules and want to reinstall webpack, and then this happens
localhost:~ ouhiroshisakai$ sudo -s
bash-3.2-sharp npm install webpack -g
+ webpack@1.0.0
updated 1 package in 0.22s
bash-3.2-sharp webpack -v
bash: webpack: command not found
The folder looks like this: