$re = '/(?<=search=)[^+]*?(?=&|$)/';
$str = 'jobs?search=term1&location=&distance=10+page=2
jobs?search=term1+term2&location=ca&distance=30
jobs?search=term1+term2+term3&location=nyc&distance=25';
preg_match_all($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