$re = '/<EventTypeCode csd-code=\"(?<myEventTypeCode>PPQ-1)\".+?<ActiveParticipant UserID=\"(?<myUserID>\w{0,})\" UserName=\"(?<myUserName>[^\"]*)\" UserIsRequestor=\"true\".*?<RoleIDCode csd-code=\"(?<myRoleCode>\w{1,})\".+?<AuditSourceIdentification.+?AuditSourceID=\"(?<myAuditSourceID>.+?)\">.+?<ParticipantObjectIdentification ParticipantObjectID=\"(?<myParticipantObjectID>\d{1,})[^\"]+?2\.16\.756\.5\.30\.1\.127.+?\" ParticipantObjectTypeCode=\"1\" ParticipantObjectTypeCodeRole=\"1\">/s';
$str = 'type=SYSCALL msg=audit(1603788735.462:431935): arch=c000003e syscall=2 success=yes exit=34 a0=1d08f80 a1=80042 a2=1a4 a3=1d08f80 items=2 ppid=1 pid=19277 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="rhn_check" exe="/usr/bin/python2.7" subj=system_u:system_r:rpm_t:s0 key="audit_rules_etc_modification"';
preg_match_all($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