How do I import global modules in Node? I get "Error: Cannot find module <module>"?

Question

I am trying to setup Node on Mac OSX Lion. It all seems to work ok, but I can't seem to import anything modules from my global modules folder. I get the error,

Error: Cannot find module <module>

If I run this: node -e require.paths , the response I get is:

[ '/usr/local/lib/node_modules',
  '/Users/Me/.node_modules',
  '/Users/Me/.node_libraries',
  '/usr/local/Cellar/node/0.4.12/lib/node' ]

Which is correct, my modules are indeed installed in /usr/local/lib/node_modules. When I try and run a script, however, I am getting this:

Error: Cannot find module 'socket.io'
    at Function._resolveFilename (module.js:326:11)
    at Function._load (module.js:271:25)
    at require (module.js:355:19)
    at Object.<anonymous> (/Users/Me/node/server.js:2:10)
    at Module._compile (module.js:411:26)
    at Object..js (module.js:417:10)
    at Module.load (module.js:343:31)
    at Function._load (module.js:302:12)
    at Array.<anonymous> (module.js:430:10)
    at EventEmitter._tickCallback (node.js:126:26)

My.bash_profile looks like this:

export PATH=/usr/local/mysql/bin:$PATH
export NODE_PATH=/usr/local/lib/node_modules
export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:/usr/local/mysql/lib/"

Would really appreciate some help, I have no idea why I can't import any libraries.

Answer 1

If you're using npm >=1.0, you can use npm link <global-package> to create a local link to a package already installed globally. ( Caveat: The OS must support symlinks. )

However, this doesn't come without its problems.

npm link is a development tool. It's awesome for managing packages on your local development box. But deploying with npm link is basically asking for problems, since it makes it super easy to update things without realizing it.

As an alternative, you can install the packages locally as well as globally.

For additional information, see

• https://nodejs.org/en/blog/npm/npm-1-0-link/
• https://nodejs.org/en/blog/npm/npm-1-0-global-vs-local-installation/

Answer 2

Node.js uses the environmental variable NODE_PATH to allow for specifying additional directories to include in the module search path. You can use npm itself to tell you where global modules are stored with the npm root -g command. So putting those two together, you can make sure global modules are included in your search path with the following command (on Linux-ish)

export NODE_PATH=$(npm root --quiet -g)

Answer 3

You can use npm link to create a symbolic link to your global package in your projects folder.

Example:

$ npm install -g express
$ cd [local path]/project
$ npm link express

All it does is create a local node_modules folder and then create a symlink express -> [global directory]/node_modules/express which can then be resolved by require('express')

Answer 4

Install any package globally as below:

$ npm install -g replace  // replace is one of the node module.

As this replace module is installed globally so if you see your node modules folder you would not see replace module there and so you can not use this package using require('replace').

because with require you can use only local modules which are present in your node module folder.

Now to use global module you should link it with node module path using below command.

$ npm link replace

Now go back and see your node module folder you could now be able to see replace module there and can use it with require('replace') in your application as it is linked with your local node module.

Pls let me know if any further clarification is needed.

Answer 5

You can use require with the path to the global module directory as an argument.

require('/path/to/global/node_modules/the_module');

On my mac, I use this:

require('/usr/local/lib/node_modules/the_module');

How to find where your global modules are? --> Where does npm install packages?

Answer 6

Setting the environment variable NODE_PATH to point to your global node_modules folder.

In Windows 7 or higher the path is something like %AppData%\\npm\\node_modules while in UNIX could be something like /home/sg/.npm_global/lib/node_modules/ but it depends on user configuration.

The command npm config get prefix could help finding out which is the correct path.

In UNIX systems you can accomplish it with the following command:

export NODE_PATH=`npm config get prefix`/lib/node_modules/

Answer 7

简单的答案是在 npm 全局根目录中运行节点。

cd $( npm root -g ) && node

Answer 8

I am using Docker. I am trying to create a docker image that has all of my node dependencies installed, but can use my local app directory at container run time (without polluting it with a node_modules directory or link). This causes problems in this scenario. My workaround is to require from the exact path where the module, eg require('/usr/local/lib/node_modules/socket.io')

Answer 9

If you are on windows cmd, you can do it via FOR /f "tokens=* delims=" %A in ('npm root --quiet -g') do set "NODE_PATH=%A" or FOR /f "tokens=* delims=" %%A in ('npm root --quiet -g') do set "NODE_PATH=%%A" in a batch file.

Answer 10

require.paths is deprecated.

Go to your project folder and type

npm install socket.io

that should install it in the local ./node_modules folder where node will look for it.

I keep my things like this:

cd ~/Sites/
mkdir sweetnodeproject
cd sweetnodeproject
npm install socket.io

Create an app.js file

// app.js
var socket = require('socket.io')

now run my app

node app.js

Make sure you're using npm >= 1.0 and node >= 4.0 .