$re = '/\n-\s.*(\n)[^-]/';
$str = 'Lorem ipsum et cras praesent mollis ullamcorper laoreet mauris imperdiet quisque
- red
- green
- blue
Lorem ipsum et cras praesent mollis ullamcorper laoreet mauris imperdiet quisque
ac adipiscing mauris ante class placerat per sem quisque phasellus sociosqu, mollis
- red
- green
- blue
bluorem ipsum et cras praesent mollis ullamcorper laoreet mauris imperdiet quisque';
preg_match_all($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