chunk_split() corrupts multibyte characters

When I use the chunk_split() function, it ruins my accented characters and special characters. How can I correct this problem?

Here is my PHP code.

if(count($text) > 0) {
    $text = implode(' ', $text);
    echo chunk_split($text, 8, '<br />'); 
}

Ruined accent characters.

&a
mp; Post
er ÀÁ�
�ÃÄÅ�
�áâã�
�åÒÓ�
�ÕÖØ�
�óôõ�
�øÈÉ�
�Ëéè�
�ëÇç�
�ÍÎÏ�
�íîï�
�ÚÛÜ�
�úûü�
�Ññ 

chunk_split isn't multibyte safe and there isn't a native mb_chunk_split.

http://php.net/manual/en/function.chunk-split.php

Here is a function to do that from a commenter in the php docs:

<?php

//from Peter from dezzignz.com 05-Apr-2010 11:30 @ php.net

function mbStringToArray ($str) {
    if (empty($str)) return false;
    $len = mb_strlen($str);
    $array = array();
    for ($i = 0; $i < $len; $i++) {
        $array[] = mb_substr($str, $i, 1);
    }
    return $array;
}

function mb_chunk_split($str, $len, $glue) {
    if (empty($str)) return false;
    $array = mbStringToArray ($str);
    $n = 0;
    $new = '';
    foreach ($array as $char) {
        if ($n < $len) $new .= $char;
        elseif ($n == $len) {
            $new .= $glue . $char;
            $n = 0;
        }
        $n++;
    }
    return $new;
}

?>

Try converting the character set before and after as seen here:

http://us3.php.net/manual/en/function.chunk-split.php#99316

Regex offers a very succinct and direct replacement for chunk_split() when dealing with multibyte characters.

Pattern breakdown:

~       #start pattern delimiter
.{8}    #match 8 of any non-newline character
\K      #forget previously matched characters
(?!$)   #not followed by the end of the string
~       #end pattern delimiter
u       #evaluate in multibyte mode

Replace with <br> but I'll demonstrate with \n.

Code: (Demo)

$str = 'áâãäąăāæåߧśšşçćčźżžýųűů';

var_export(
    preg_replace(
        '~.{8}\K(?!$)~u',
        "\n",
        $str
    )
);

Output:

'áâãäąăāæ
åߧśšşçć
čźżžýųűů'