php模拟python的unichr函数

网上找的,感觉还行.

有需要就拿走吧.

function unichr($dec) {
  if ($dec < 128) {
    $utf = chr($dec);
  } else if ($dec < 2048) {
    $utf = chr(192 + (($dec - ($dec % 64)) / 64));
    $utf .= chr(128 + ($dec % 64));
  } else {
    $utf = chr(224 + (($dec - ($dec % 4096)) / 4096));
    $utf .= chr(128 + ((($dec % 4096) - ($dec % 64)) / 64));
    $utf .= chr(128 + ($dec % 64));
  }
  return $utf;
}