Utf-8、gb2312都支持的汉字截取

<?php

/***************************************************************************
*            cut_string.php
*        ------------------------------
*    Date        : Jul 16, 2005
*    Copyright    : none
*    Mail        :
*
*    作用:截取中文字符.
*
*
***************************************************************************/

function cut_str($string, $sublen, $start = 0, $code = 'UTF-8')
{
    if($code == 'UTF-8')
    {
        $pa = "/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/";
        preg_match_all($pa, $string, $t_string);

        if(count($t_string[0]) - $start > $sublen) return join('', array_slice($t_string[0], $start, $sublen))."...";
        return join('', array_slice($t_string[0], $start, $sublen));
    }
    else
    {
        $start  = $start*2;
        $sublen = $sublen*2;
        $strlen = strlen($string);
        $tmpstr = '';
        for($i=0; $i<$strlen; $i++)
        {
            if($i>=$start && $i<($start+$sublen))
            {
            if(ord(substr($string, $i, 1))>129) $tmpstr.= substr($string, $i, 2);
            else $tmpstr.= substr($string, $i, 1);
            }
            if(ord(substr($string, $i, 1))>129) $i++;
        }
        if(strlen($tmpstr)<$strlen ) $tmpstr.= "...";
        return $tmpstr;
    }
}

?>
--------------------------------------------------------------------------------

cut_str(字符串,  截取长度,  开始长度, 编码);
编码默认为 utf-8
开始长度默认为 0