$re = '/CEF:0.+[\r\n]?/m';
$str = 'CEF:0|Forcepoint CASB|Cloud Service Monitoring|1.0|63575192763|Activity|0|act=Monitor app= cat=Normal Activity cs1= destinationServiceName=Office365 deviceExternalId= deviceFacility=true deviceProcessName=loadBalancers dhost= dpriv=User dst=0.0.0.0 duser=14dd43c6-a792-4c07-a33b-c5e561a129de dvc=10.1.2.12 dvchost=somedomain end=1600408516000 externalId=0 fsize=-1 msg=//United States/Unknown outcome=Success proto= reason=modify request= requestClientApplication=Unknown/Unknown/"" rt=1600408516000 sourceServiceName=Unmanaged src=someIP start=1600408516000 suser= cs2= cs3= cs5=false cs6= dproc=Unknown flexString1=mc_rg-int-qa-eus02_aks-int01-qa-eus02_eastus2,kubernetes-internal cs4=14dd43c6-a792-4c07-a33b-c5e561a129de flexString2= AD.ThreatRadarCategory= AD.TORNetworks= AD.MaliciousIPs= AD.AnonymousProxies= AD.IPChain=someIP AD.IPOrigin=External AD.samAccountName=14dd43c6-a792-4c07-a33b-c5e561a129de
CEF:0|Forcepoint CASB|Cloud Service Monitoring|1.0|63575216734|Activity|0|act=Monitor app= cat=Normal Activity cs1= destinationServiceName=Office365 deviceExternalId= deviceFacility=false deviceProcessName= dhost= dpriv=User dst=0.0.0.0 duser=someuser_849fcb2777e9@somedomain.onmicrosoft.com dvc=10.1.2.12 dvchost=somedomain end=1600406172000 externalId=0 fsize=-1 msg=//United States/Unknown outcome=Success proto= reason=login request= requestClientApplication=Unknown/Unknown/"" rt=1600406172000 sourceServiceName=Unmanaged src=someIP start=1600406172000 suser= cs2= cs3= cs5=false cs6= dproc=Unknown flexString1= cs4=someaccount9@somedomain.onmicrosoft.com flexString2= AD.ThreatRadarCategory= AD.TORNetworks= AD.MaliciousIPs= AD.AnonymousProxies= AD.IPChain=someIP AD.IPOrigin=Internal AD.samAccountName=someaccount9@somedomain.onmicrosoft.com
CEF:0|Forcepoint CASB|Cloud Service Monitoring|1.0|63575216736|Activity|0|act=Monitor app= cat=Normal Activity cs1= destinationServiceName=Office365 deviceExternalId= deviceFacility=true deviceProcessName= dhost= dpriv=User dst=0.0.0.0 duser=someaccount@somedomain.onmicrosoft.com dvc=10.1.2.12 dvchost=somedomain end=1600405713000 externalId=0 fsize=-1 msg=//United States/Unknown outcome=Success proto= reason=login request= requestClientApplication=Unknown/Unknown/"" rt=1600405713000 sourceServiceName=Unmanaged src=someIP start=1600405713000 suser= cs2= cs3= cs5=false cs6= dproc=Unknown flexString1= cs4=someaccount@somedomain.onmicrosoft.com flexString2= AD.ThreatRadarCategory= AD.TORNetworks= AD.MaliciousIPs= AD.AnonymousProxies= AD.IPChain=someIP AD.IPOrigin=External AD.samAccountName=someaccount@somedomain.onmicrosoft.com
CEF:0|Forcepoint CASB|Cloud Service Monitoring|1.0|63575216738|Activity|0|act=Monitor app= cat=Normal Activity cs1= destinationServiceName=Office365 deviceExternalId= deviceFacility=false deviceProcessName= dhost= dpriv=User dst=0.0.0.0 duser=someaccount@somedomain.com dvc=10.1.2.12 dvchost=somedomain end=1600405674000 externalId=0 fsize=-1 msg=/1225/United States/Unknown outcome=Success proto= reason=login request= requestClientApplication=Unknown/Unknown/"" rt=1600405674000 sourceServiceName=Unmanaged src=someIP start=1600405674000 suser= cs2= cs3= cs5=false cs6= dproc=Unknown flexString1= cs4=someaccount flexString2= AD.ThreatRadarCategory= AD.TORNetworks= AD.MaliciousIPs= AD.AnonymousProxies= AD.IPChain=someIP AD.IPOrigin=Internal AD.samAccountName=someaccount
CEF:0|Forcepoint CASB|Cloud Service Monitoring|1.0|63575216735|Activity|0|act=Monitor app= cat=Normal Activity cs1= destinationServiceName=Office365 deviceExternalId= deviceFacility=false deviceProcessName= dhost= dpriv=User dst=0.0.0.0 duser=someaccount9@somedomain.onmicrosoft.com dvc=10.1.2.12 dvchost=somedomain end=1600406165000 externalId=0 fsize=-1 msg=//United States/Unknown outcome=Success proto= reason=login request= requestClientApplication=Unknown/Unknown/"" rt=1600406165000 sourceServiceName=Unmanaged src=someIP start=1600406165000 suser= cs2= cs3= cs5=false cs6= dproc=Unknown flexString1= cs4=someaccount@somedomain.onmicrosoft.com flexString2= AD.ThreatRadarCategory= AD.TORNetworks= AD.MaliciousIPs= AD.AnonymousProxies= AD.IPChain=someIP AD.IPOrigin=Internal AD.samAccountName=someaccount@somedomain.onmicrosoft.com';
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