I have a requirement to fetch the current SID of running Oracle instance, I know a keyword which will be part of SID, how can i fetch and assign it to variable.

I am trying something 

```
ps -ef | grep pmon | grep TESTDB    
oracle    5527 23570  0 05:03 pts/5    00:00:00 /bin/ksh -c ps -ef | grep pmon | grep TESTDB    
oracle   26617     1  0 Sep24 ?        01:10:57 ora_pmon_TESTDB02

```

From above how do i extract just TESTDB02 

Thanks in advance