Question

I’ve started using npm for JavaScript package management recently. Although I do have a fair understanding of package management in different environments (let’s say using apt, rvm/gem, and pythonbrew/virtualenv/pip), I don’t quite understand how npm fully fits in.

I would like to know more on how the "-g" flag works and why should I use it.

As in most blogs and wiki, they refer to using "-g" when installing without explaining why, and I understand that these packages are installed globally.

• But why should I always install these packages globally?
• What does it mean to install these packages without the "-g" flag?
• What do I do to installed packages locally, let’s say sandboxed for different projects?
• How can I then, make a list of npm packages used in a project and bundle it in the project if I needed it to check it in with version control (if possible at all)?

Answer 1

-g is the global install flag, as explained in this answer. It’s covered in detail in this node blog post.

The rules of thumb:

• Install globally if the package provides command-line tools
• Install locally if you’re using the package as part of your application
• Install globally and locally if both use-cases apply