$re = '/(?i)[0-9]+[\r\n]+.*[\r\n]+S0B0L/';
$str = '39983
"set x 1"
random_user
39984
"set x 45"
S0B0L
39985
"set x 23"
random_user';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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