Develop Reference

"npm-run-all" Is Not Recognized As an Internal or External Command

I installed npm-run-all and also configured the environment variable (which may or may not be not required) on my Windows machine but am getting an error:
'npm-run-all' is not recognized as an internal or external command,
operable program or batch file
I am trying to build my current project with npm run build which includes the script where the error is thrown:
npm-run-all -p build-css build-webpack
Do I have to do any additional things to make it run?

Make sure the npm-run-all is in your package.json devDependencies.
If npm-run-all is present in your package.json, run npm i
If not present install it, run: npm i npm-run-all -D
If error is still present, follow these steps:
Remove node_modules folder: run rm -rf node_modules
Install all dependecies: run npm i
Hope this helps!

You may just need to run the following command first (from the directory with the package.json file)
npm install

Please do that like this.
npm i npm-run-all -g
And then this issue will be fixed.

You have a couple of options here, besides installing npm-run-all as a global package as suggested by #Vaibhav in the comments:
1) Create an NPM script
The package.json file has a scripts section which can used to define shortcuts for anything you need to run while you're working on your app. There are some pre-defined scripts, like run or test than can be executed with simply npm start/npm test or you can define anything you like and then run it with npm run my-script-name. You could try:
{
"scripts": {
"start": "npm-run-all -p build-css build-webpack"
}
}
Any NPM module referenced here "just works" (i.e. the path to the executable is resolved under the hood by NPM)
2) NPX
In newer versions of NPM (i.e. >= 5.2 or so), the "NPX" executable is provided. This has a similar effect to running commands inside an NPM script. You would run:
npx npm-run-all -p build-css build-webpack
Again, the path would be automatically resolved.
If you have an older NPM install, you can also install it separately:
npm install -g npx

npm install -g npm-run-all
Works for me.
Double check if npm-run-all is in your package.json devDependencies.

I had same problem while using code editor Brackets.
To resolve the error, I did the following steps.
Add nodejs new system variable to your PC under Control Panel -> System -> Advanced System Settings
;C:\Program Files\nodejs\
After that, re-run command:
npm

I don't know if this would help anyone, but I got this error because I was doing nodemon server.js instead of nodemon server/server.js. I wasn't in the right folder!

Did you reopen the terminal after you installed node?
If you have installed npm with the current terminal window open. Your terminal window will not have loaded the latest path settings (with npm location) to find the npm application to run the command. In this case try below steps .
Try closing the current terminal session.
Reopen a new session.
Try the command again ( will pick up the new path settings with npm installed)

This worked for me.
npm audit fix --force
Also you can try downgrading your autoprefixer, seems version 10.0.0 doesn't work well with postcss
npm i autoprefixer#9.8.6

install optimise with npm from optimist.js file

Trying to fix an offline install of the Carto tool from Mapbox on Ubuntu 14.04. Currently, node is giving me an error, it cant find the optimist module. I can manually find an optimist.js file, but its not under a "proper" node_modules directory like the other Carto dependancies are (e.g. underscore). I'm very new to npm and node, so my question is "is there a way to properly install optimise from this optimist.js file I have?"

If you just want to use the package,
$ npm install -g carto
should be enough to get you started. Note that you might need to use sudo for that command.
Node.js is centered around a package manager called "npm". Every npm project has a package.json at its root directory that specifies its dependencies, package name, version, et al. By looking at carto's package.json even if you installed optimist successfully you will encounter some more require errors.
If you want to develop the package, after cloning it with Git run
$ npm install
inside the directory. That will install all dependencies (including devDependencies that are not installed when you are installing the package itself) for you.
There are plenty of tutorials on how Node.js works, like http://nodeguide.com/beginner.html. Those should give you a more comprehensive view than this answer.
With a proper package manager like npm, you should never using a random script found on the internet to fake it as a module.
Good luck!
UPDATE now that one knows how npm works, if you want to make it available locally to be installed, you can do something like this
# With Internet
# Make a cache
$ mkdir carto-cache
# Make a temporary directory where the initial copy of carto is installed
$ mkdir to-be-discarded
$ cd to-be-discarded
# Now install the package, and cache the package in carto-cache
$ npm install --cache ../carto-cache --prefix . carto
# You can now remove to-be-discarded, and copy carto-cache to wherever you want.
# Without internet
$ npm install --cache carto-cache --cache-min 999999999 -g carto
(derived from https://github.com/npm/npm/issues/2568)

What the difference between install a module with npm node console or in package.json

I'm new and I need to use node for off-line use so, I'm trying to understand how the install modules work.
It's the same if I use npm install express or included it in the package.json?

The way a package is installed will be the same whether you manually type npm install express or put it in your package.json and then do npm install. The difference comes when you try to install your Node project elsewhere.
For example, if your code was checked into GitHub and you didn't include a package.json with all of the dependencies listed, then when the project was downloaded you would have to manually re-install all of the dependencies on the command line in order for it to work. But if you had checked in a package.json with the code, then you could run npm install to install all of the dependencies at once, and not have to remember which ones were necessary.
In addition, the package.json allows you to specify an "approximate version" of a dependency to use. This way if a few packages in your project share a dependency and they all specify similar "approximate versions", only one version will be installed and it will be shared between packages. This saves some install time.

Nothing actually. But you don't want to do that again and again. So you might as well put your module dependencies in your package.json

Where does npm install packages?

Can someone tell me where can I find the Node.js modules, which I installed using npm?

Global libraries
You can run npm list -g to see which global libraries are installed and where they're located. Use npm list -g | head -1 for truncated output showing just the path. If you want to display only main packages not its sub-packages which installs along with it - you can use - npm list --depth=0 which will show all packages and for getting only globally installed packages, just add -g i.e. npm list -g --depth=0.
On Unix systems they are normally placed in /usr/local/lib/node or /usr/local/lib/node_modules when installed globally. If you set the NODE_PATH environment variable to this path, the modules can be found by node.
Windows XP - %USERPROFILE%\AppData\npm\node_modules
Windows 7, 8 and 10 - %USERPROFILE%\AppData\Roaming\npm\node_modules
Non-global libraries
Non-global libraries are installed the node_modules sub folder in the folder you are currently in.
You can run npm list to see the installed non-global libraries for your current location.
When installing use -g option to install globally
npm install -g pm2 - pm2 will be installed globally. It will then typically be found in /usr/local/lib/node_modules (Use npm root -g to check where.)
npm install pm2 - pm2 will be installed locally. It will then typically be found in the local directory in /node_modules

The command npm root will tell you the effective installation directory of your npm packages.
If your current working directory is a node package or a sub-directory of a node package, npm root will tell you the local installation directory. npm root -g will show the global installation root regardless of current working directory.
Example:
$ npm root -g
/usr/local/lib/node_modules
See the documentation.

For globally-installed modules:
The other answers give you platform-specific responses, but a generic one is this:
When you install global module with npm install -g something, npm looks up a config variable prefix to know where to install the module.
You can get that value by running npm config get prefix
To display all the global modules available in that folder use npm ls -g --depth 0 (depth 0 to not display their dependencies).
If you want to change the global modules path, use npm config edit and put prefix = /my/npm/global/modules/prefix in the file or use npm config set prefix /my/npm/global/modules/prefix.
When you use some tools like nodist, they change the platform-default installation path of global npm modules.

On windows I used npm list -g to find it out. By default my (global) packages were being installed to C:\Users\[Username]\AppData\Roaming\npm.

If you are looking for the executable that npm installed, maybe because you would like to put it in your PATH, you can simply do
npm bin
or
npm bin -g

If a module was installed with the global (-g) flag, you can get the parent location by running:
npm get prefix
or
npm ls -g --depth=0
which will print the location along with the list of installed modules.

Not direct answer but may help ....
The npm also has a cache folder, which can be found by running npm config get cache (%AppData%/npm-cache on Windows).
The npm modules are first downloaded here and then copied to npm global folder (%AppData%/Roaming/npm on Windows) or project specific folder (your-project/node_modules).
So if you want to track npm packages, and some how, the list of all downloaded npm packages (if the npm cache is not cleaned) have a look at this folder. The folder structure is as {cache}/{name}/{version}
This may help also https://docs.npmjs.com/cli/cache

In earlier versions of NPM modules were always placed in /usr/local/lib/node or wherever you specified the npm root within the .npmrc file. However, in NPM 1.0+ modules are installed in two places. You can have modules installed local to your application in /.node_modules or you can have them installed globally which will use the above.
More information can be found at https://github.com/isaacs/npm/blob/master/doc/install.md

To get a compact list without dependencies simply use
npm list -g --depth 0

The easiest way would be to do
npm list -g
to list the package and view their installed location.
I had installed npm via chololatey, so the location is
C:\MyProgramData\chocolatey\lib\nodejs.commandline.0.10.31\tools\node_modules
C:\MyProgramData\ is chocolatey repo location.

As the other answers say, the best way is to do
npm list -g
However, if you have a large number of npm packages installed, the output of this command could be very long and a big pain to scroll up (sometimes it's not even possible to scroll that far back).
In this case, pipe the output to the more program, like this
npm list -g | more

I was beginning to go mad while searching for the real configuration, so here is the list of all configuration files on linux:
/etc/npmrc
/home/youruser/.npmrc
/root/.npmrc
./.npmrc in the current directory next to package.json file (thanks to #CyrillePontvieux)
on windows:
c/Program\ Files/nodejs/node_modules/npm/npmrc
Then in this file the prefix is configured:
prefix=/usr
The prefix is defaulted to /usr in linux, to ${APPDATA}\npm in windows
The node modules are under $prefix tree, and the path should contain $prefix/bin
There may be a problem :
When you install globally, you use "sudo su" then the /root/.npmrc may be used!
When you use locally without sudo: for your user its the /home/youruser/.npmrc.
When your path doesn't represent your prefix
When you use npm set -g prefix /usr it sets the /etc/npmrc global, but doesn't override the local
Here is all the informations that were missing to find what is configured where. Hope I have been exhaustive.

You can find globally installed modules by the command
npm list -g
It will provide you the location where node.js modules have been installed.
C:\Users\[Username]\AppData\Roaming\npm
If you install node.js modules locally in a folder, you can type the following command to see the location.
npm list

Echo the config: npm config ls or npm config list
Show all the config settings: npm config ls -l or npm config ls --json
Print the effective node_modules folder: npm root or npm root -g
Print the local prefix: npm prefix or npm prefix -g
(This is the closest parent directory to contain a package.json file or node_modules directory)
npm-config | npm Documentation
npm-root | npm Documentation
npm-prefix | npm Documentation

Expanding upon other answers.
npm list -g
will show you the location of globally installed packages.
If you want to output that list to a file that you can then easily search in your text editor:
npm list -g > ~/Desktop/npmfiles.txt

From the docs:
In npm 1.0, there are two ways to install things:
globally —- This drops modules in {prefix}/lib/node_modules, and puts executable files in {prefix}/bin, where {prefix} is usually
something like /usr/local. It also installs man pages in
{prefix}/share/man, if they’re supplied.
locally —- This installs your package in the current working directory. Node modules go in ./node_modules, executables go in
./node_modules/.bin/, and man pages aren’t installed at all.
You can get your {prefix} with npm config get prefix. (Useful when you installed node with nvm).

From the docs:
Packages are dropped into the node_modules folder under the prefix.
When installing locally, this means that you can
require("packagename") to load its main module, or
require("packagename/lib/path/to/sub/module") to load other modules.
Global installs on Unix systems go to {prefix}/lib/node_modules.
Global installs on Windows go to {prefix}/node_modules (that is, no
lib folder.)
Scoped packages are installed the same way, except they are grouped
together in a sub-folder of the relevant node_modules folder with the
name of that scope prefix by the # symbol, e.g. npm install
#myorg/package would place the package in
{prefix}/node_modules/#myorg/package. See scope for more details.
If you wish to require() a package, then install it locally.
You can get your {prefix} with npm config get prefix. (Useful when you installed node with nvm).
Read about locally.
Read about globally.

Windows 10: When I ran npm prefix -g, I noticed that the install location was inside of the git shell's path that I used to install. Even when that location was added to the path, the command from the globally installed package would not be recognized. Fixed by:
running npm config edit
changing the prefix to 'C:\Users\username\AppData\Roaming\npm'
adding that path to the system path variable
reinstalling the package with -g.

In Ubuntu 14.04 they are installed at
/usr/lib/node_modules

For Windows 7, 8 and 10 -
%USERPROFILE%\AppData\Roaming\npm\node_modules
Note:
If you are somewhere in folder type cd .. until you are in C: directory. Then, type cd %USERPROFILE%\AppData\Roaming\npm\node_modules. Then, magically, %USERPROFILE% will change into Users\YourUserProfile\.
I just wanted to clarify on ideas referred by Decko in the first response. npm list -g will list all the bits you have globally installed. If you need to find your project related npm package then cd 'your angular project xyz', then run npm list. It will show list of modules in npm package. It will also give you list of dependencies missing, and you may require to effectively run that project.

Btw, npm will look for node_modules in parent folders (up to very root) if can not find in local.

If you're trying to access your global dir from code, you can backtrack from process.execPath. For example, to find wsproxy, which is in {NODE_GLOBAL_DIR}/bin/wsproxy, you can just:
path.join(path.dirname(process.execPath), 'wsproxy')
There's also how the npm cli works # ec9fcc1/lib/npm.js#L254 with:
path.resolve(process.execPath, '..', '..')
See also ec9fcc1/lib/install.js#L521:
var globalPackage = path.resolve(npm.globalPrefix,
'lib', 'node_modules', moduleName(pkg))
Where globalPrefix has a default set in ec9fcc1/lib/config/defaults.js#L92-L105 of:
if (process.env.PREFIX) {
globalPrefix = process.env.PREFIX
} else if (process.platform === 'win32') {
// c:\node\node.exe --> prefix=c:\node\
globalPrefix = path.dirname(process.execPath)
} else {
// /usr/local/bin/node --> prefix=/usr/local
globalPrefix = path.dirname(path.dirname(process.execPath))
// destdir only is respected on Unix
if (process.env.DESTDIR) {
globalPrefix = path.join(process.env.DESTDIR, globalPrefix)
}
}

If you have Visual Studio installed, you will find it comes with its own copy of node separate from the one that is on the path when you installed node yourself - Mine is in C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VisualStudio\NodeJs.
If you run the npm command from inside this directory you will find out which node modules are installed inside visual studio.

Express module not found when installed with NPM

When I try to run the app.js file created by express, I get the following error:
$ node app.js
node.js:134
throw e; // process.nextTick error, or 'error' event on first tick
^
Error: Cannot find module 'express'
at Function._resolveFilename (module.js:320:11)
When I type in express --version I get a return statement of 2.3.3. I used npm to install express. I had to manually make npm using these instructions:
git clone http://github.com/isaacs/npm.git
cd npm
sudo make install
The error is Error: Cannot find module 'express'.
Do I need to do something after installing npm and express in order to make express see the modules created by npm?
My node is version: 0.4.6
My express is version: 2.3.3
My npm is version: 1.0.6
Express is installed globally. I used the -g flag to install it.
Edit: When I try "node -e require.paths" I get:
[ '/home/user/.node_modules',
'/home/user/.node_libraries',
'/usr/local/lib/node' ]
So, node isn't detecting the npm installation. How do I get node to detect the npm installation?

Install express
npm install -g express
Create a new app
express your_app
cd into app directory
cd your_app
use npm link to resolve modules
npm link express

Use local installs for require(), and global installs for command-line apps.
If you need both, use the npm link command.

On Ubuntu 12.04 you have to add the export NODE_PATH=/usr/local/lib/node_modules to your /.bashrc to use globally installed modules.

It appears that while npm had been updated to install global modules into /usr/local/lib/node_modules, Node's own require.paths does not yet reflect this change.
There are two reasonable solutions:
Add the following code to the top of your application:
require.paths.push('/usr/local/lib/node_modules');
Pro: non-invasive, easy to add
Con: requires discipline, future versions of node will restrict access to require.paths
As root, execute:
ln -s /usr/local/lib/node_modules /usr/local/lib/node
Pro: reasonably non-invasive
Con: requires root, modifies linux fs, might not survive system updates

I had the same problem. This worked for me though:
Seems like npm (now?) installs node modules to /usr/local/lib/node_modules/ and not /usr/local/lib/node/
What I did was simply to copy everything from node_modules to node: sudo cp -r /usr/local/lib/node_modules/* usr/local/lib/node/ and now it seems to be working for me.
Hope this helps you :-)

What about NODE_PATH=/usr/local/lib/node_modules in .bashrc or .bash_profile? I think it's the real correct way.

Set NODE_PATH=NODE_HOME\node_modules.
I'm using windows 7 and it works fine.

It may happen, if you're using windows, that the environment variable NODE_PATH is not set, and thus when you execute node fileName.js it won't find the libraries.
Check for the variable on your console, and if not present, create it. Give it the NODE_HOME\node_modules value, where NODE_HOME is your node install dir. This path is where npm install puts every module upon downloading.

require.paths is removed, use the NODE_PATH environment variable instead.

It looks like the easiest way to do this is to run npm install from your app's folder. This tells npm to hook everything up.
It's the last instruction after express <appname>:
...
dont forget to install dependencies:
$ cd <appname> && npm install

Finally with Linux a good way to do is to use the command : sudo apt-get install node-express
But with express 4 we must use express-generator to make app skeleton, install it with 'npm install express-generator -g', and then run 'express myapp' command.
see also install express

for mac users
cd /usr/local/lib/node
sudo ln -s ../node_modules/* ./$1

I installed gulp and when I ran this gulp command in the command line I got a gulp: command not found error. It appeared that it installed gulp in my local folder that is /home/YOURUSERNAME/.node/lib/node_modules and not in the global npm folder.
You can check npm root folder by running this command: npm root -g, which was returning my personal directory /home/YOURUSERNAME/.node/lib/node_modules and not the expected /usr/local/lib/node_modules.
You can fix this by running npm config set prefix /usr/local command.

For all problems with express with a mac computer:
The solution is:
chown to your user the .npm folder :
sudo chown -R Webmaste /Users/webmaste/.npm/
At your test folder or your folder:
sudo npm install -g express#2.5.8
Invoke express from your actual location:
/usr/local/share/npm/bin/express
sudo cd . && npm install
Finally:
node app
the final message in the console should look like this:
Express server listening on port 3000 in development mode