Adding […] string for a custom excerpt function

I have a custom except function I use all the time, it will cut off in the middle of a sentence, but it works great. Just drop this baby into your functions.php and then <?php the_excerpt_truncate(100); ?> just change the 100 to your desired character limit.

// THE EXCERPT MAX CHAR

function the_excerpt_truncate($charlength) {
    $excerpt = get_the_excerpt();
    $charlength++;

    if ( mb_strlen( $excerpt ) > $charlength ) {
        $subex = mb_substr( $excerpt, 0, $charlength - 5 );
        $exwords = explode( ' ', $subex );
        $excut = - ( mb_strlen( $exwords[ count( $exwords ) - 1 ] ) );
        if ( $excut < 0 ) {
            echo mb_substr( $subex, 0, $excut );
        } else {
            echo $subex;
        }
        echo '...';
    } else {
        echo $excerpt;
    }
}