$re = '/(?:^RXHOST|^rxhost)([a-zA-Z0-9\s\-].*\-{2,}[a-zA-Z0-9\s\-].*|[a-zA-Z0-9\s\-].*\s{2,}[a-zA-Z0-9\s\-].*)/m';
$str = 'RXHOST ZZ PQ1-P-TAS-QZV4YTTT5645644-SIT-01JAN79-VL-01JAN30-MANAGE-TIME-OVER ALL-H/F1/Z3
RXHOST ZZ PQ1-A-TAS-XZV456NGFF45644-MIT-01JAN79-V-01JAN30-MANAGEMENT-TIME-H/F1/Z3
RXHOST ZZ PQ1-I-TAS-BZV456456FF44-GIT-01JAN79-VL-01JAN30-MANAGEMENT-TIME/F1/Z3
RXHOST ZZ PQ1-D-TAS-UZV4QQ5645644-SIT-01JAN79-V-01JAN30-MANAGEMENT-TIME-OVER ALL-H/F1
RXHOST ZZ PQ1-F-TAS-TZV45QDF645644-SIT-01JAN79-V-01JAN30-MANAGE-TIME-H/F1
RXHOST ZZ PQ1-P-TAS-PZV45FF645644-SIT-01JAN79-JL-01JAN30-MANAGEMENT-TIME/F1
RXHOST ZZ PQ1-P-TAS-QZV456FBF45644-QIT-01JAN79-V-01JAN30-MANAGEMENT-TIME-OVER ALL-H/Z3
RXHOST ZZ PQ1-I-SAT-TZV456FGF45644-EIT-01JAN79-V-01JAN30-MANAGEMENT-TIME-H/Z3
RXHOST ZZ PQ1-P-SAT-OZV456EWEW45644-TIT-01JAN79-VL-01JAN30-MANAGE-TIME/Z3
RXHOST ZZ PQ1-P-SAT-ZZV456GFG45644-SIT-01JAN79-V-01JAN30-MANAGEMENT-TIME-OVER ALL-H
RXHOST ZZ PQ1-D-SAT-XZV4HHH5645644-YIT-01JAN79-V-01JAN30-MANAGE-TIME-H
RXHOST ZZ PQ1-A-SAT-JZVOPPO45645644-PIT-01JAN79-JL-01JAN30-MANAGEMENT-TIME
';
preg_match_all($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