[Crazy]

<?php

$text = 'aa bbbb ccccccc ddddddddddddd eeeeeeeeeeeeeeee';

define('SPLIT_MAX_LEN',10);
define('SPLIT_PART_LEN',8);


$text = preg_replace_callback('/\S{'.SPLIT_MAX_LEN.'}\S+/', 'split_long_word', $text);

function split_long_word($matched) {
$temp = "";
$word = $matched[0];
$charsLeft = strlen($word);
$i = 0;
while ($charsLeft>0) {
$partLen = min(SPLIT_PART_LEN,$charsLeft);
$temp .= substr($word,$i,$partLen).' ';
$i += $partLen;
$charsLeft -= $partLen;
}
return substr($temp,0,strlen($temp)-1);
}

echo $text;

?>