How to extract URI following rex command?

[karthi2809]

How to extract URI following rex command?
My field

URI=/v4/cp/members/summary?hcid=

AN5635356

&firstnm=ELLEN&lastnm=BRODBINE&dob=1962-01-02

My rex command :

| rex field=_raw "URI=/v4/cp/members/summary?(?[^ ]*)"

?hcid=AN5635356&firstnm=ELLEN&lastnm=BRODBINE&dob=1962-01-02

Expected output:
AN5635356

[vinod94]

Try this,

| makeresults 
| eval data="URI=/v4/cp/members/summary?hcid=AN5635356&firstnm=ELLEN&lastnm=BRODBINE&dob=1962-01-02" 
| rename data as _raw 
| rex field=_raw "hcid\=(?P<OUTPUT>[^\&]*)"

[damien_chillet]

You need to escape special characters such as / and ?

Try URI=\/v4\/cp\/members\/summary\?hcid=(?P<hcid>[^&]+)

The value will be stored in field hcid