$re = '/^Cust=([^,]+)(?:,Region Info=([^,]*))?(?:,Data=(.*))?$/m';
$str = 'Cust=abc,Region Info=xyz,Data=123
Cust=abd,Region Info=xyz,Data=124
Cust=acc hit,Data=125
Cust=abc,Region Info=xyz,Data=126
Cust=abg nss,Region Info=xaz,Data=127
Cust=evc,Region Info=atz';
preg_match_all($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