$re = '/(.{1,20})(?:\s|$)/';
$str = 'I have String Search the whole web or only webpages After doing some research I think that I want to combine an if/then statement with lookahead, i.e. go to the character limit and if there is a character following it that is a space, add an ellipses, if it is a number or letter, go to the final space within the limit and add an ellipses';
preg_match_all($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