node can not find webpack module on windows 10

Question

I have installed webpack both globally (first) and for a certain project also (PC, windows 10). Seems that the project dir contains all the folders that it needed:

c:\Users\srgg6701\Documents\Projects\Compilers\Webpack\try>npm install webpack --save-dev
npm WARN optional dep failed, continuing [email protected]
[email protected] node_modules\webpack
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected]
├── [email protected] ([email protected], [email protected])
├── [email protected] ([email protected])
├── [email protected] ([email protected])
├── [email protected] ([email protected], [email protected])
├── [email protected] ([email protected], [email protected])
├── [email protected] ([email protected], [email protected])
├── [email protected] ([email protected], [email protected])
├── [email protected] ([email protected], [email protected], [email protected], [email protected])
├── [email protected] ([email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected])
└── [email protected] ([email protected], [email protected], [email protected])

But when I run the command in the project dir:

c:\Users\srgg6701\Documents\Projects\Compilers\Webpack\try>node webpack ./app.js bundle.js

It reveals an error:

module.js:338
    throw err;
    ^
Error: Cannot find module 'c:\Users\srgg6701\Documents\Projects\Compilers\Webpack\try\webpack'
    at Function.Module._resolveFilename (module.js:336:15)
    at Function.Module._load (module.js:286:25)
    at Function.Module.runMain (module.js:475:10)
    at startup (node.js:117:18)
    at node.js:951:3

Then I check installed package for node:

c:\Users\srgg6701\Documents\Projects\Compilers\Webpack\try>npm ls --depth=0

It says that's OK (?):

c:\Users\srgg6701\Documents\Projects\Compilers\Webpack\try
└── [email protected]

Nevertheless, the error remains. Pls, tell me, can it be fixed and how?!

Just in case, here is the content of the node_modules/webpack/package.json file:

{
  "name": "webpack",
  "version": "1.12.9",
  "author": {
    "name": "Tobias Koppers @sokra"
  },
  "description": "Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.",
  "dependencies": {
    "async": "^1.3.0",
    "clone": "^1.0.2",
    "enhanced-resolve": "~0.9.0",
    "esprima": "^2.5.0",
    "interpret": "^0.6.4",
    "loader-utils": "^0.2.11",
    "memory-fs": "~0.3.0",
    "mkdirp": "~0.5.0",
    "node-libs-browser": ">= 0.4.0 <=0.6.0",
    "optimist": "~0.6.0",
    "supports-color": "^3.1.0",
    "tapable": "~0.1.8",
    "uglify-js": "~2.6.0",
    "watchpack": "^0.2.1",
    "webpack-core": "~0.6.0"
  },
  "license": "MIT",
  "devDependencies": {
    "benchmark": "^1.0.0",
    "bundle-loader": "~0.5.0",
    "codecov.io": "^0.1.2",
    "coffee-loader": "~0.7.1",
    "coffee-script": "^1.10.0",
    "component-webpack-plugin": "~0.2.0",
    "coveralls": "^2.11.2",
    "css-loader": "~0.15.0",
    "diff": "^2.0.2",
    "eslint": "^1.1.0",
    "eslint-plugin-nodeca": "^1.0.3",
    "express": "~4.13.1",
    "extract-text-webpack-plugin": "~0.8.0",
    "file-loader": "~0.8.0",
    "glob": "^5.0.14",
    "i18n-webpack-plugin": "~0.2.0",
    "istanbul": "^0.3.13",
    "jade": "^1.11.0",
    "jade-loader": "~0.7.0",
    "js-beautify": "^1.5.10",
    "json-loader": "~0.5.1",
    "less": "^2.5.1",
    "less-loader": "^2.0.0",
    "mocha": "~2.2.0",
    "mocha-lcov-reporter": "0.0.2",
    "raw-loader": "~0.5.0",
    "script-loader": "~0.6.0",
    "should": "^7.0.2",
    "style-loader": "~0.12.0",
    "url-loader": "~0.5.0",
    "val-loader": "~0.5.0",
    "vm-browserify": "~0.0.0",
    "webpack-dev-middleware": "^1.0.0",
    "worker-loader": "~0.6.0"
  },
  "engines": {
    "node": ">=0.6"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/webpack/webpack.git"
  },
  "homepage": "https://github.com/webpack/webpack",
  "main": "lib/webpack.js",
  "web": "lib/webpack.web.js",
  "bin": {
    "webpack": "./bin/webpack.js"
  },
  "files": [
    "lib/",
    "bin/",
    "buildin/",
    "hot/",
    "web_modules/"
  ],
  "scripts": {
    "pretest": "npm run lint && npm run beautify-lint",
    "test": "mocha",
    "travis": "npm run cover -- --report lcovonly",
    "lint": "eslint lib bin hot scripts",
    "beautify-lint": "node ./scripts/beautify-check",
    "beautify": "node ./scripts/beautify-rewrite",
    "precover": "npm run lint && npm run beautify-lint",
    "cover": "istanbul cover -x *.runtime.js node_modules/mocha/bin/_mocha",
    "publish-patch": "npm run lint && npm run beautify-lint && mocha && npm version patch && git push && git push --tags && npm publish"
  },
  "gitHead": "9766f2bde3c3f3e7b3b0e914c9cb81ea3a12e823",
  "bugs": {
    "url": "https://github.com/webpack/webpack/issues"
  },
  "_id": "[email protected]",
  "_shasum": "2a031d66189839cc5cbf2c68f80566da2e14ff4e",
  "_from": "[email protected]*",
  "_npmVersion": "2.10.1",
  "_nodeVersion": "0.12.4",
  "_npmUser": {
    "name": "sokra",
    "email": "[email protected]"
  },
  "maintainers": [
    {
      "name": "sokra",
      "email": "[email protected]"
    }
  ],
  "dist": {
    "shasum": "2a031d66189839cc5cbf2c68f80566da2e14ff4e",
    "tarball": "http://registry.npmjs.org/webpack/-/webpack-1.12.9.tgz"
  },
  "directories": {},
  "_resolved": "https://registry.npmjs.org/webpack/-/webpack-1.12.9.tgz",
  "readme": "ERROR: No README data found!"
}

Solution

When you install a module globally npm install -g webpack (as is required by webpack), it actually becomes available on your command line. So you just need to run:

webpack ./app.js bundle.js

As for the error which you were getting when running:

node webpack ./app.js bundle.js

that's because when you run node webpack you're actually (supposedly) passing the file webpack.js (or webpack/index.js) to node, hence the "Cannot find module" error.