Get cache location with env variable

Question

I get get the NPM cache location using:

  cache_location="$(npm get cache)"

however, is this value also represented by an env variable that I can read?

Something like NPM_CACHE_LOCATION?

https://docs.npmjs.com/cli/cache

Answer 1

Short answer: It depends on when/how you want to access it, as there is no env variable, (e.g. NPM_CACHE_LOCATION), available whilst npm is not running.

You'll need to invoke npm config get cache or npm get cache as you are currently doing.

However, once npm is running the configuration parameters are put into the environment with the npm_ prefix.

The following demonstrates this...

---

Discover which env variables are available:

As a way to find out what env variable(s) npm puts in the environment, you can utilize printenv in an npm-script. For example in package.json add:

...
"scripts": {
  "print-env-vars": "printenv | grep \"^npm_\""
},
...

Then run the following command:

npm run print-env-vars

Get the cache location via an env variable:

In the resultant log to the console, (i.e. after running npm run print-env-vars), you'll see that there's the npm_config_cache environment variable listed. It reads something like this:

npm_config_cache=/Users/UserName/.npm

In the docs it states:

configuration

Configuration parameters are put in the environment with the npm_config_ prefix. For instance, you can view the effective root config by checking the npm_config_root environment variable.

Note: Running printenv | grep "^npm_" directly via the CLI returns nothing.

Accessing the cache location with env variable:

1. You can access the cache location via an npm-script, For example:

   "scripts": {
     "cache-loc-using-bash": "echo $npm_config_cache",
     "cache-loc-using-win": "echo %npm_config_cache%"
   },
   

   See cross-var for utilizing a cross-platforms syntax.

2. Accessing the npm cache location via a Nodejs script. For example:

   const cacheLocation = process.env.npm_config_cache;
   console.log(cacheLocation)
   

   Note: This node script will need to be invoked via an npm-script for the process.env.npm_config_cache to be available. Invoking it via the command line running, e.g. node ./somefile.js will return undefined - this further demonstrates that the parameters with the _npm prefix are only put into the environment whilst npm is running.

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Not ideal, however you could set your own environment variable using export of course:

export NPM_CACHE_LOCATION="$(npm get cache)"

and unset to remove it:

unset NPM_CACHE_LOCATION