Question

I need to easily install packages based on some predefined variables.

So i set

export NPMDIR=dev

or

export NPMDIR=prod

then in .npmrc

prefix=/usr/local/npm/$NPMDIR

and all packages are installed in /usr/local/npm/$NPMDIR literally instead
of /usr/local/npm/dev, /usr/local/npm/prod etc.

Any clues?

Answer 1

most likely you need brackets around your variables:

prefix=/usr/local/npm/${NPMDIR}