module.exports = function hexdump(ab) {
  var ui8 = new Uint8Array(ab);
  var bytecount = 0;
  var head = '        0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F';
  var trail;
  var str = [].slice.call(ui8).map(function (i) {
    var h = i.toString(16);
    if (h.length < 2) {
      h = '0' + h;
    }
    return h;
  }).join('').match(/.{1,2}/g).join(' ').match(/.{1,48}/g).map(function (str) {
    var lead = bytecount.toString(16);
    bytecount += 16;

    while (lead.length < 7) {
      lead = '0' + lead;
    }

    return lead + ' ' + str;
  }).join('\n');
  trail = ab.byteLength.toString(16);
  while (trail.length < 7) {
    trail = '0' + trail;
  }
  return head + '\n' + str + '\n' + trail;
};