php 中英文混合字符串的截取函数

/**
* 截取中英文混合的字符串
* by bbs.it-home.org
*/
function mb_str_split($string){
    # Split at all position not after the start: ^
    # and not before the end: $
    //$string = iconv('gb2312', 'utf-8//ignore', $string);
    return preg_split('/(?}
$string = 'q345e q345d q345c，q345d圆钢,q345e圆钢nm360a耐磨板,欧标s355低合金板 bs700mc汽车板,汽车qste460tm结构钢,船板ah36/eh36/dh36,美标容器板 耐候钢 弹簧钢';
//$charlist = mb_str_split($string);
echo mb_chunk_split($string, 30, '..', true);
echo '';
echo mb_chunk_split($string, 10, '');

function mb_chunk_split($string, $length, $end = '..', $once = false){
    //$string = iconv('gb2312', 'utf-8//ignore', $string);
    $charlist = mb_str_split($string);
    $i = 0;
    $j = 0;
    $once_array = array();
    foreach($charlist as $value){
        /* if($once){
          if(($i + $j) > $length){
          $i--; //尽可能少的
          break;
          }
          }else{
          if(($i + $j) >= $length){
          $once_array[] = implode('', array_slice($charlist, $once_leng, $i));
          $once_leng += $i;
          $i = $j = 0;
          }
          } */

        if(($i + $j) >= $length){
            if($once)
                return implode('', array_slice($charlist, 0, $i-1)) . (count($charlist)             $once_array[] = $i;
            $i = $j = 0;
        }


        if(ord($value) > 127)
            $j++; //中文算2个宽度
        /*if($value == ',')
            $j--;*/
        $i++;
    }
    //末尾补齐
    if(array_sum($once_array)         $once_array[] = $i;

    $str_arr = array();
    $once_leng = 0;
    foreach($once_array as $value){
        $str_arr[] = implode('', array_slice($charlist, $once_leng, $value));
        $once_leng += $value;
    }

    return implode($end, $str_arr);
    //return implode('', array_slice($charlist, 0, $i)) . (count($charlist) }
?>