truncate
    truncate(string $text, int $length=100, array $options)
    Cuts a string to the $length and adds a suffix with ‘ending’ if the text is longer than $length. If ‘exact’ is passed as false, the truncation will occur after the next word ending. If ‘html’ is passed as true, html tags will be respected and will not be cut off.

echo $this->Text->truncate(
    'The killer crept forward and tripped on the rug.',
    22,
    array(
        'ending' => '...',
        'exact' => false
    )
);