中文截取函数

/*** 中文截取函数*/function mbsubstr($str, $start=0, $length, $suffix=true, $charset="utf-8") {if(function_exists("mb_substr"))$slice = mb_substr($str, $start, $length, $charset);elseif(function_exists('iconv_substr')) {$slice = iconv_substr($str,$start,$length,$charset);}else{$re['utf-8']   = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";$re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";$re['gbk']    = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";$re['big5']   = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";preg_match_all($re[$charset], $str, $match);$slice = join("",array_slice($match[0], $start, $length));}if(strlen($str) > strlen($slice)){return $suffix ? $slice.'...' : $slice;}else{return $slice;}}