$re = '`(?P<users>(ID)\s\w+}`';
$str = 'Accepted publickey for infra from 192.168.41.36 port 62249 ssh2: RSA-CERT SHA256:cMZkSAyWJVdM4LhSn+X6UQ0srnDppQ33gqZRgWFcw18 ID leguernc (serial 14277886801353047704) CA RSA SHA256:sTN+SLxbKWgPZ95WV2aw/kF/MoTCOVL+zSycrUPThqo';
preg_match_all($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