AFAIK，npm软件包的发行商不需要提供许可证，或者至少不需要以标准的方式提供。
幸运的是，this package能够显示node_modules中所有软件包的许可证信息。它也有一个简单的API，所以获取信息并将其显示在网页上应该相当容易。

我终于找到了https://www.npmjs.com/package/get-repository-url，它做了我想要的。

我已经这样做了，请随意修改它以适合您的用例（只需在项目目录（node getLicenses.js > LICENSES.txt）上使用节点运行它：

const FS = require('fs');

const packageJSON = JSON.parse(FS.readFileSync('package.json').toString());
const dependencies = packageJSON.dependencies;

const LICENSE_NAMES = [
  'LICENSE',
  'license',
  'LICENSE.md',
];

let FAILED_TO_FIND_LICENSES = false;

let libraries = Object.keys(dependencies);

libraries.forEach(key => {
  console.log('\n' + key);
  console.log('================================');

  const path = 'node_modules/' + key;

  let license = null;

  LICENSE_NAMES.forEach(name => {
    try {
      license = FS.readFileSync(path + '/' + name).toString();
    } catch (e) {}
  });

  if (!license) {
    try {
      let libraryPackageFile = FS.readFileSync(path + '/package.json').toString();
      // You can try to get the license from the package.json here
    } catch (e) {}
  }

  if (license) {
    console.log(license);
  } else {
    console.log('License not found');
    FAILED_TO_FIND_LICENSES = true;

    try { // This is to help update the LICENSE_NAMES before re-run it
      let files = FS.readdirSync(path);
      files.forEach(file => {
        console.log(file);
      });
    } catch (e) {}
  }
});

if (FAILED_TO_FIND_LICENSES) {
  console.error('WARN: The license for some dependencies was not found!');
}