$re = '/(?m)\bApplication Name:\s*(.+)(?:\n(?!\s*={3,}\r?$).*)*^\s*Secret Key:\s*(.+)/';
$str = 'Application Details for the XYZ application:
=========================================================
Application Name: XYXZW1
Application Id: XYZ353WERX
Application Details for the XYZ application:
=========================================================
Application Name: XYXZW2
Application Id: XYZ353WERX
Application Details for the XYZ application:
=========================================================
Application Name: XYXZW3
Application Id: XYZ353WERX
Secret Key: XYZ86JBHHSD
Application Details for the XYZ application:
=========================================================
Application Name: XYXZW4
Application Id: XYZ353WERX
Secret Key: XYZ86JBHHSD';
preg_match_all($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