报错：
The operation was rejected by your operating system.
//操作被您的操作系统拒绝。
It is likely you do not have the permissions to access this file as the current user
//您可能没有权限作为当前用户访问此文件。
If you believe this might be a permissions issue, please double-check the
//如果您认为这可能是权限问题，请重新检查
permissions of the file and its containing directories, or try running
//文件及其包含目录的权限，或者尝试运行
npm ERR! the command again as root/Administrator (though this is not recommended).
//命令再次作为根/管理员（虽然这是不推荐的）。
解决：
sudo npm install -g cnpm --registry=https://registry.npm.taobao.org --verbose
此时会提示让你输入一个密码，即你的用户开机密码，输入回车即可，（看不见你输入的内容也没关系）如果出现下面的信息（最下面几行）说明安装成功：
……
added 692 packages in 29.865s
npm verb exit [ 0, true ]
npm info ok
查看命令：
cnpm -v
==============
过程中遇见最多的错误是:权限
很无语
