Print the local prefix to standard output. This is the closest parent directory
to contain a package.json file or node_modules directory, unless -g is
also specified.
If -g is specified, this will be the value of the global prefix. See
npm config for more detail.
Example
npm prefix
/usr/local/projects/foo
npm prefix -g
/usr/local
Configuration
global
Default: false
Type: Boolean
Operates in "global" mode, so that packages are installed into the prefix
folder instead of the current working directory. See
folders for more on the differences in behavior.
packages are installed into the {prefix}/lib/node_modules folder, instead
of the current working directory.