$re = '/START.*messageDetails\>(?<Start_Date>\d+-\d+-\d+\s+\d+:\d+:\d+)\/.*END.*messageDetails\>(?<End_ate>\d+-\d+-\d+\s+\d+:\d+:\d+)/m';
$str = 'START</enteringExiting><logLevel>INFO</logLevel><messageType>LOG</messageType><applicationName>GstarSOA</applicationName<programName>GstarRecipientService_MF</programName><functionName>GetRecipient</functionName><host>PerfNode0</host><messageDetails>2022-06-17 04:10:53/utility/logging"><enteringExiting>END</enteringExiting><logLevel>INFO</logLevel><messageType>LOG</messageType><applicationName>GstarSOA</applicationName><programName>GstarRecipientService_MF</programName<functionName>GetRecipient</functionName><host>PerfNode0</host><messageDetails>2022-06-17 04:10:53';
preg_match_all($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