Use the list command with the -g flag to see all packages that are installed globally:
npm list -g
To check if a specific package is installed globally, you can provide the name of package (grunt in this case) as seen below:
npm list -g grunt
Or you can use grep to filter on package names:
npm list -g | grep grunt
Source: https://docs.npmjs.com/cli/ls
--depth. For example: npm list --depth 1 --global csats-mturk > /dev/null 2>&1.Here's a more detailed example.
npm list --depth 0 --global tern to check if tern was installed globally as if npm install -g tern
grep seems like a fairly reliable solution given the comments about npm exiting with an error due to unmet dependenciesnpm list --depth 1 --global packagename > /dev/null 2>&1 You can then check the exit status to see if it's installed or not. Thanks Adam Monsen.
--depth 1! that's what I was looking for. Actually I'm using now npm list --depth 0 -g
$? always returns 1 for me, even if the package IS installed or NOT installed.
--global, --local are deprecated. Use --location=global instead."
To check if a specific package is installed globally, execute:
npm list -g [package-name] Let's take Grunt as an example. If it is installed globally, you should see something like this:
npm list -g grunt Output:
C:\Users\xxxxxxx\AppData\Roaming\npm └── [email protected] If it is not installed globally, you should see something like this
npm list -g grunt Output:
C:\Users\xxxxxxx\AppData\Roaming\npm └── (empty) To check if a specific package is installed locally you can execute the same commands as above, but without the -g parameter.
Source: How to check if npm package was installed globally or locally.
You can list all global packages with the command:
npm ls -g Or check for a specific package with:
npm ls -g package-name For example: npm ls -g @angular/cli
--global, --local are deprecated. Use --location=global instead."In Windows we use the following command to find out whether the package is installed or not. Please refer image for details.
npm list -g | find "create" 
From your package with sindresorhus/is-installed-globally
https://github.com/sindresorhus/is-installed-globally
Usage:
const isInstalledGlobally = require('is-installed-globally'); // With `npm install your-package` console.log(isInstalledGlobally); //=> false // With `npm install --global your-package` console.log(isInstalledGlobally); //=> true I found this useful when I had to distribute prebuilt files with my package: How to publish a npm package with distribution files? With this package, I can check if the installation is local or global, and then use relative paths for local installations, as shown here.
