sniffypedia/lib/utils.js

An open, collaborative lookup of radio-identifiable (sniffable) things, represented as structured data. We believe in an open Internet of Things.

/**
 * Copyright reelyActive 2016-2021
 * We believe in an open Internet of Things
 */


/**
 * Convert the given data to a hexadecimal string of the given number of bytes.
 * @param {Object} data The data to convert (Number, String or Buffer).
 * @param {Number} length The target length of the string in bytes.
 * @param {boolean} reverseEndianness Optionally reverse the endianness.
 * @return {String} The data as a hexadecimal string.
 */
function convertToHexString(data, length, reverseEndianness) {
  let hexString = null;

  if(Number.isInteger(data) && (data >= 0)) {
    hexString = data.toString(16).padStart(length * 2, '0');
  }
  if(Buffer.isBuffer(data)) {
    hexString = data.toString('hex').padStart(length * 2, '0');
  }
  if(typeof data === 'string') {
    hexString = data.padStart(length * 2, '0');
  }

  if(hexString && (reverseEndianness === true)) {
    return hexString.match(/.{2}/g).reverse().join('');
  }

  return hexString;
}


module.exports.convertToHexString = convertToHexString;