I know that I can install a module in node.js using npm install module-name. but try that multiiple times and it will install again. I am tired of forgetting that I have installed modules globally and I am installing them again. How do I know if a module installation already exists globally in node?
you have to try
npm ls
will give you the list of installed modules
to list global packages
npm ls -g
to list global packages with more detail
npm ls -gl
same way to list local packages with detail
npm ls -l
also you can type
npm help ls
for more details regarding this
If you want to know whether you have a specific module installed, you can run npm explore <module>. If you get an error, then you don't have that module and you should download it.
This is a bit of a hack, but it works.