php字符串截取函数（支持中文 utf-8截取）

function str_wrap1($str,$elen=30)
{
$tlen = mb_strlen($str,"utf8"); //共有多少字
//$elen = 8; //每行字符串长度8个字符、4个汉字
$dlen = 0; //每行显示长度
$str_wrap = '';
for($i=0;$i {
$tmpchar = mb_substr($str,$i,1,"utf8");
if(strlen($tmpchar) == 3)
$charlen = 2;
else
$charlen = 1;
if( $dlen {
$dlen += $charlen;
$str_wrap .= $tmpchar;
}
else
{
$str_wrap .= "
".$tmpchar;
$dlen = $charlen;
}
}
return $str_wrap;
}

echo str_wrap1($str,5);