Sort selected layers in Photoshop by layer name

SortLayers.js

var idx_shift = 0
try {
  activeDocument.backgroundLayer
} catch (e) {
  idx_shift = 1
}
var list = get_selected_layers()
if (list) {
  var orig_idx = list.slice()
  function cmp(a, b) {
	var x = expand_numbers(a[0]);
	var y = expand_numbers(b[0]);
	if (x > y) return -1;
	if (x < y) return 1;
	return 0;

}
  list.sort(cmp)
  for (var i = list.length - 1; i >= 0; i--) {
	  set_layers_index(list[i][2], orig_idx[i][1])
  }
}
alert('Done!')

//////////////////////////////////////////////////////////////////
function set_layers_index(id, idx) {
  try {
    var d = new ActionDescriptor()
    var r1 = new ActionReference()
    r1.putIdentifier(charIDToTypeID('Lyr '), id)
    var r2 = new ActionReference()
    r2.putIndex(charIDToTypeID('Lyr '), idx - idx_shift)
    d.putReference(charIDToTypeID('null'), r1)
    d.putReference(charIDToTypeID('T   '), r2)
    executeAction(charIDToTypeID('move'), d, DialogModes.NO)
  } catch (e) {
    alert(e)
    throw e
  }
}

//////////////////////////////////////////////////////////////////
function get_selected_layers() {
  try {
    var r = new ActionReference()
    r.putProperty(charIDToTypeID('Prpr'), stringIDToTypeID('targetLayers'))
    r.putEnumerated(
      charIDToTypeID('Dcmn'),
      charIDToTypeID('Ordn'),
      charIDToTypeID('Trgt')
    )
    var list = executeActionGet(r).getList(stringIDToTypeID('targetLayers'))
    var len = list.count
    var selected_layers = new Array()
    for (var i = 0; i < len; i++) {
      try {
        var idx = list.getReference(i).getIndex() + idx_shift
        var r = new ActionReference()
        r.putIndex(charIDToTypeID('Lyr '), idx)
        var ret = executeActionGet(r)
        selected_layers.push([
          ret.getString(stringIDToTypeID('name')),
          idx,
          ret.getString(stringIDToTypeID('layerID')),
        ])
      } catch (e) {
        alert(e)
        return null
      }
    }
    return selected_layers
  } catch (e) {
    return null
  }
}

////////////////////////////////////////////////////////////////////////////////////////////
function expand_numbers(s, max_digit) {
  if (max_digit == undefined) max_digit = 10
  var digit_cnt
  s = s.toString()
  var len = s.length
  var s1 = ''
  for (var i = len - 1; i >= 0; i--) {
    var c = s.charAt(i)
    if (c >= '0' && c <= '9') {
      if (digit_cnt == undefined) digit_cnt = 1
      else ++digit_cnt
      s1 += c
    } else if (digit_cnt != undefined) {
      if (digit_cnt < max_digit)
        for (var n = 0; n < max_digit - digit_cnt; n++) s1 += '0'
      s1 += c
      digit_cnt = undefined
    } else {
      s1 += c
    }
  }
  if (digit_cnt != undefined && digit_cnt < max_digit)
    for (var n = 0; n < max_digit - digit_cnt; n++) s1 += '0'
  len = s1.length
  var ret = ''
  for (var i = len - 1; i >= 0; i--) ret += s1.charAt(i)
  ret = ret.toUpperCase()
  return ret
}