Sindre Sorhus有一本很棒的github.com/sindresorhus/guides岁指南，我在这里转载过.

Install npm packages globally without sudo on OS X and Linux

默认情况下，npm会在项目中本地安装包.您还可以在全局安装软件包(例如npm install -g <package>个)(对于命令行应用程序很有用).然而，这样做的缺点是，您需要是root用户(或使用sudo)才能进行全局安装.

下面是一种为给定用户全局安装软件包的方法.

1.为您的全局包创建一个目录

mkdir "${HOME}/.npm-packages"

2. Reference this directory for future usage in your .bashrc/.zshrc:

NPM_PACKAGES="${HOME}/.npm-packages"

3. Indicate to npm where to store your globally installed package. In your $HOME/.npmrc file add:

prefix=${HOME}/.npm-packages

4. Ensure node will find them. Add the following to your .bashrc/.zshrc:

NODE_PATH="$NPM_PACKAGES/lib/node_modules:$NODE_PATH"

5. Ensure you'll find installed binaries and man pages. Add the following to your .bashrc/.zshrc:

PATH="$NPM_PACKAGES/bin:$PATH"
# Unset manpath so we can inherit from /etc/manpath via the `manpath`
# command
unset MANPATH # delete if you already modified MANPATH elsewhere in your config
MANPATH="$NPM_PACKAGES/share/man:$(manpath)"

查看npm-g_nosudo自动完成上述步骤

NOTE:如果您正在运行OS X，.bashrc文件可能还不存在，终端将从另一个文件(如.profile或.bash_profile)获取其环境参数.这些文件也位于用户的主文件夹中.在这种情况下，只需向其添加以下行即可指示终端也加载.bashrc文件:

source ~/.bashrc