What npm install -s mean?

Question

I am installing some packages on NPM, sometimes I have to write -s and -g? What do they mean?

npm install -s socket.io
npm install -g xxxxxxx

Answer 1

npm -g <package> will install a package globally on your machine. Without the -g or --global flag, the package will be installed locally in the directory you were in when you ran the command.

npm -S <package> with an uppercase -S or --save will install the package and save it to your dependencies in your package.json, although I believe that is now the default behavior in current npm. I recommend reading the docs if you're unfamiliar with what's happening when you pass different options to npm.

Answer 2

@gmmetheny answered the question about the global -g flag, but -s appears to silence the output of the command (at least in npm v7.0.15).

In other words, including -s (or --silent) in your npm install command means that it will have no output (only a newline):

> npm install -s example-package1 example-package2

This may be useful for running the command in a script.

Running the command without the -s flag echoes information about what was installed, e.g.:

> npm install example-package1 example-package2

npm WARN deprecated some-pkg@1.2.3: this library is no longer supported

added 160 packages, and audited 160 packages in 6s

14 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

You can diff the resulting directories created after running each variant of the command and you can verify that the effects are the same.

As @Max mentioned, this option is NOT mentioned in the npm docs (at least not in any prevalent location where a user might find it after a reasonable amount of searching).

Answer 3

npm install -g will install a package globally on your machine, means it will be available for all other user in computer. Without the -g or --global flag, the package will be installed locally in the directory you are currently working in, and will be available to you only.

npm install -s this will install package and also make and entry in package.json file. -s stands for --save. without -s, npm will install the package but will not make any entry in package.json.