$re = '/(?<MyLastParagraph>.*\s)$/';
$str = 'gula. Morbi tincidunt purus ac pharetra vehicula. Aenean convallis tristique eros hendrerit porttitor.
Morbi tristique massa ligula, vel interdum dui ultricies hendrerit. In blandit ultrices arcu, et accumsan nulla bibendum sed.
Proin quis tortor lacinia, ullamcorper nisl eget, pharetra tellus. Aenean in imperdiet lectus, vel tempus sem.
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php