/**
 * 转码UTF-8
 * @param $filename 文件路径
 * @return bool|resource
 */
public function fopen_utf8($filename){
    $handle = fopen($filename, 'r');
    $bom = fread($handle, 2);
    rewind($handle);

    if($bom === chr(0xff).chr(0xfe) || $bom === chr(0xfe).chr(0xff)){
        $encoding = 'UTF-16';
    } else {
        $file_sample = fread($handle, 1000) + 'e';
        rewind($handle);
        $encoding = mb_detect_encoding($file_sample , 'UTF-8, UTF-7, ASCII, EUC-JP,SJIS, eucJP-win, SJIS-win, JIS, ISO-2022-JP');
    }
    if ($encoding){
        stream_filter_append($handle, 'convert.iconv.'.$encoding.'/UTF-8');
    }
    return ($handle);
}