[oracle@localhost ~]$ ps -ef | grep LISTENER
oracle   28864     1  0 13:41 ?        00:00:00 /u01/oracle/bin/tnslsnr LISTENER -inherit
oracle   28893 24393  0 13:41 pts/3    00:00:00 grep --color=auto LISTENER
[oracle@localhost ~]$ ps -ef | grep oracle  
root     24376  1300  0 12:27 ?        00:00:00 sshd: oracle [priv]
oracle   24380 24376  0 12:27 ?        00:00:00 sshd: oracle@pts/3
oracle   24393 24380  0 12:27 pts/3    00:00:00 -bash
oracle   28864     1  0 13:41 ?        00:00:00 /u01/oracle/bin/tnslsnr LISTENER -inherit
oracle   28901 24393  0 13:41 pts/3    00:00:00 ps -ef
oracle   28902 24393  0 13:41 pts/3    00:00:00 grep --color=auto oracle