CODE EXAMPLE FOR JAVASCRIPT

js get bytearray from file

document.querySelector('input').addEventListener('change', function() {

  var reader = new FileReader();
  reader.onload = function() {

    var arrayBuffer = this.result,
      array = new Uint8Array(arrayBuffer),
      binaryString = String.fromCharCode.apply(null, array);

    console.log(binaryString);

  }
  reader.readAsArrayBuffer(this.files[0]);

}, false);