PHP 字符截取 解决中文的截取问题,不用mb系列

            [U]复制代码[/U] 代码如下:
function Cut_string($string, $start ,$sublen, $extstring='...', $code = 'UTF-8') {//Cut_string开始
if($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, $sublen)).$extstring;
return join('', array_slice($t_string[0], $start, $sublen));
}
else
{
$start = $start*2;
$sublen = $sublen*2;
$strlen = strlen($string);
$tmpstr = '';
for($i=0; $i=$start && $i129)
{
$tmpstr.= substr($string, $i, 2);
}
else
{
$tmpstr.= substr($string, $i, 1);
}
}
if(ord(substr($string, $i, 1))>129) $i++;
}
if(strlen($tmpstr)