NPM License Checker

Table of Contents

• NPM License Checker
  • Table of Contents
  • Introduction
  • Changes
    • Version 3.1.0
    • Version 3.0.1
    • Version 3.0.0
  • All options in alphabetical order:
  • Exclusions
  • Examples
  • Custom format
  • Requiring
  • Debugging
  • How Licenses are Found
  • Related information sources on the internet

Introduction

_This is a fork of rseidelsohn' license-checker-rseidelsohn - It mainly exists to exlude README which rarely has license files

Please notice: Version 1.2.2 is the last version working fine on node v12. From Version 2 on, you will need at least Node v14 to run this NPM license checker. Thanks to @daniel-schulz for pointing this out!

Ever needed to see all the license info for a module and its dependencies?

It's this easy:

npm install -g npm-license-checker-alt

mkdir foo
cd foo
npm install yui-lint
npm-license-checker-alt

You should see something like this:

├─ [email protected]
│  ├─ repository: http://github.com/chriso/cli
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-glob
│  └─ licenses: UNKNOWN
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-graceful-fs
│  └─ licenses: UNKNOWN
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/inherits
│  └─ licenses: UNKNOWN
├─ [email protected]
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-lru-cache
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/node-lru-cache
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/minimatch
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/minimatch
│  └─ licenses: MIT
├─ [email protected]
│  ├─ repository: https://github.com/isaacs/sigmund
│  └─ licenses: UNKNOWN
└─ [email protected]
   ├─ licenses: BSD
   └─ repository: http://github.com/yui/yui-lint

An asterisk next to a license name means that it was deduced from an other file than package.json (README, LICENSE, COPYING, ...) You could see something like this:

└─ [email protected]
   ├─ repository: https://github.com/visionmedia/debug
   └─ licenses: MIT*

Changes

Version 1.0.1

First real version

All options in alphabetical order:

• --angularCli is just a synonym for --plainVertical
• --csv output in csv format.
• --csvComponentPrefix prefix column for component in csv format.
• --customPath to add a custom Format file in JSON
• --development only show development dependencies.
• --direct look for direct dependencies only
• --excludeLicenses [list] exclude modules which licenses are in the comma-separated list from the output
• --excludePackages [list] restrict output to the packages (either "package@fullversion" or "package@majorversion" or only "package") not in the semicolon-seperated list
• --excludePackagesStartingWith [list] exclude modules which names start with the comma-separated list from the output (useful for excluding modules from a specific vendor and such). Example: --excludePackagesStartingWith "webpack;@types;@babel"
• --excludePrivatePackages restrict output to not include any package marked as private
• --failOn [list] fail (exit with code 1) on the first occurrence of the licenses of the semicolon-separated list
• --files [path] copy all license files to path and rename them to module-name@version-LICENSE.txt.
• --includeLicenses [list] include only modules which licenses are in the comma-separated list from the output
• --includePackages [list] restrict output to the packages (either "package@fullversion" or "package@majorversion" or only "package") in the semicolon-seperated list
• --json output in json format.
• --limitAttributes [list] limit the attributes to be output.
• --markdown output in markdown format.
• --nopeer skip peer dependencies in output.
• --onlyAllow [list] fail (exit with codexclusionse 1) on the first occurrence of the licenses not in the semicolon-seperated list
• --onlyunknown only list packages with unknown or guessed licenses.
• --out [filepath] write the data to a specific file.
• --plainVertical output license info in plain vertical format like Angular CLI does
• --production only show production dependencies.
• --relativeLicensePath output the location of the license files as relative paths
• --relativeModulePath output the location of the module files as relative paths
• --start [filepath] path of the initial json to look for
• --summary output a summary of the license usage',
• --unknown report guessed licenses as unknown licenses.
• --version The current version
• --help The text you are reading right now :)

Exclusions

A list of licenses is the simplest way to describe what you want to exclude.

You can use valid SPDX identifiers. You can use valid SPDX expressions like MIT OR X11. You can use non-valid SPDX identifiers, like Public Domain, since npm does support some license strings that are not SPDX identifiers.

Examples

npm-license-checker-alt --json > /path/to/licenses.json
npm-license-checker-alt --csv --out /path/to/licenses.csv
npm-license-checker-alt --unknown
npm-license-checker-alt --customPath customFormatExample.json
npm-license-checker-alt --excludeLicenses 'MIT, MIT OR X11, BSD, ISC'
npm-license-checker-alt --includePackages '[email protected];[email protected];[email protected]'
npm-license-checker-alt --excludePackages 'internal-1;internal-2'
npm-license-checker-alt --onlyunknown

Custom format

The --customPath option can be used with CSV to specify the columns. Note that the first column, module_name, will always be used.

When used with JSON format, it will add the specified items to the usual ones.

The available items are the following:

• copyright
• description
• email
• licenseFile
• licenseModified
• licenses
• licenseText
• name
• publisher
• repository
• url
• version

You can also give default values for each item. See an example in customFormatExample.json.

Requiring

var checker = require('npm-license-checker-alt');

checker.init(
    {
        start: '/path/to/start/looking',
    },
    // eslint-disable-next-line no-unused-vars
    function (err, packages) {
        if (err) {
            //Handle error
        } else {
            //The sorted package data
            //as an Object
        }
    },
);

Debugging

license-checker uses debug for internal logging. There’s two internal markers:

• npm-license-checker-alt:error for errors
• npm-license-checker-alt:log for non-errors

Set the DEBUG environment variable to one of these to see debug output:

$ export DEBUG=npm-license-checker-alt*; npm-license-checker-alt
scanning ./yui-lint
├─ [email protected]
│  ├─ repository: http://github.com/chriso/cli
│  └─ licenses: MIT
# ...

How Licenses are Found

We walk through the node_modules directory with the read-installed-packages module. Once we gathered a list of modules we walk through them and look at all of their package.json's, We try to identify the license with the spdx module to see if it has a valid SPDX license attached. If that fails, we then look into the module for the following files: LICENSE, LICENCE, COPYING,

If one of the those files are found (in that order) we will attempt to parse the license data from it with a list of known license texts. This will be shown with the * next to the name of the license to show that we "guessed" at it.

Related information sources on the internet

• ChooseALicense.com - aims at helping you in choosing an open source license for your project
• TLDRLegal.com - aims at exlaining complicated legal details of software licenses in easy to understand english