Find the process id – Example : Oracle Listener

[grid@server01 admin]$ ps -ef|grep -i listen
grid     21687     1  0 Apr21 ?        00:20:28 /oracle/grid/12.2/bin/tnslsnr LISTENER_SCAN1 -no_crs_notify -inherit
grid     21938     1  0 Apr21 ?        00:32:52 /oracle/grid/12.2/bin/tnslsnr LISTENER -no_crs_notify -inherit
root     31840 31805  0 Apr21 ?        00:00:00 hald-addon-input: Listening on /dev/input/event3 /dev/input/event0 /dev/input/event1
68       32017 31805  0 Apr21 ?        00:00:00 hald-addon-acpi: listening on acpid socket /var/run/acpid.socket
grid     32608 13797  0 14:21 pts/5    00:00:00 grep -i listen

Display the Environment Variables

[grid@server01 admin]$ strings /proc/21938/environ
__CRS_ACTIVE_VERSION=12.2.0.1.0
__CLSAGFW_TYPE_NAME=ora.mgmtlsnr.type
CHECK_WRAP_TRACE=/oracle/gridbase/crsdata/debug/oraagent_trace_needed.txt
ORA_CRS_HOME=/oracle/grid/12.2
TERM=linux
__CRSD_CONNECT_STR=(ADDRESS=(PROTOCOL=IPC)(KEY=CRSD_IPC_SOCKET_11))
NLS_LANG=AMERICAN_AMERICA.AL32UTF8
CRF_HOME=/oracle/grid/12.2
GIPCD_PASSTHROUGH=false
ENVCMD=/bin/env
__CRSD_AGENT_NAME=/oracle/grid/12.2/bin/oraagent_grid
_ORA_AGENT_ACTION=TRUE
__CRSD_MSG_FRAME_VERSION=2
LD_LIBRARY_PATH=/oracle/grid/12.2/lib:/etc/ORCLcluster/lib
WRAP_ENVFILE=/oracle/gridbase/crsdata/debug/oraagent_env_20066.log
START_MODE=
FILEOWNER=
__CLSAGENT_INCARNATION=2
CRS_LIMIT_MEMLOCK=unlimited
FILEOWNER_ID=
__CRS_START_MODE=normal
ORACLE_BASE=/oracle/gbase
.......