npm install -g 错误集锦

1、切换源安装：npm config set registry http://registry.cnpmjs.org，参考http://yijiebuyi.com/blog/b12eac891cdc5f0dff127ae18dc386d4.html
2、寻找源，请使用npm源管理器nrm：http://segmentfault.com/a/1190000000473869

3、ionic安装报错：

　　error:if you are behind a proxy， please make sure that the proxy config is set properly...

　　error:in most cases you are behind a proxy or have bad network settings....

　 解决办法：切换源，npm config set registry http://r.cnpmjs.org/