pajamas/pj.js

#!/usr/bin/env node

const fs = require('fs');
const pj = require('./lib').pj;

if (process.argv[2] === '--help') {
  console.log(`Usage: pj [path]

A path is a string of the form object.property.subproperty representing the
property to look up. For example, consider the following package.json file:

{
  "name": "My Package",
  "version": "0.0.1",
  "license": "MIT",
  "keywords": ["node", "json", "cli"]
  "scripts": {
    "test": "node test.js"
  }
}

You could run \`pj name\`, which would print "My Package", or
\`pj scripts.test\` which would print "node test.js".`);
  process.exit();
}

const path = process.argv.length < 3 ? [] : process.argv[2].split('.');

fs.readFile('./package.json', 'utf-8', (err, contents) => {
  if (err) {
    switch (err.code) {
      case 'ENOENT':
        console.error('No package.json found in the current directory');
        process.exit();
      default:
        throw err;
    }
  }
  const result = pj(contents, path);
  switch (result.constructor) {
    case Error:
      console.error(result.message);
      break;
    default:
      console.log(result);
  }
});