As the oracle user issue these commands:

UNIX> sqlplus / as sysdba

SQL*Plus: Release 10.2.0.4.0 - Production on Wed Oct 20 10:07:24 2010

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area 1.7180E+10 bytes
Fixed Size                  2114208 bytes
Variable Size            2164264288 bytes
Database Buffers         1.4999E+10 bytes
Redo Buffers               14659584 bytes
Database mounted.
Database opened.
SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

UNIX> sqlplus / as sysdba

SQL*Plus: Release 10.2.0.4.0 - Production on Wed Oct 20 11:29:41 2010

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> shutdown
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

UNIX> lsnrctl start SID_LISTENER

LSNRCTL for IBM/AIX RISC System/6000: Version 10.2.0.4.0 - Production on 20-OCT-2010 11:11:23

Copyright (c) 1991, 2007, Oracle.  All rights reserved.

Starting /opt/oracle/product/10.2/bin/tnslsnr: please wait...

TNSLSNR for IBM/AIX RISC System/6000: Version 10.2.0.4.0 - Production
System parameter file is /opt/oracle/product/10.2/network/admin/listener.ora
Log messages written to /opt/oracle/product/10.2/network/log/sid_listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=dbserver)(PORT=2824)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))

UNIX> lsnrctl status SID_LISTENER

lsnrctl stop SID_LISTENER

UNIX>/opt/oracle/product/10.2/network/admin>cat tnsnames.ora
# tnsnames.ora Network Configuration File: /opt/oracle/product/10.2/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.

SID_LISTENER =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 2824))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = sid)
    )
  )

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

emctl start dbconsole
emctl status dbconsole
emctl stop dbconsole

#!/bin/ksh

# Oracle environment
ORACLE_BASE=/opt/oracle
ORACLE_HOME=/opt/oracle/product/10.2
CLASSPATH=${ORACLE_BASE}/product/jre:${ORACLE_BASE}/jlib:${ORACLE_BASE}/rdbms/jlib:#{ORACLE_BASE}/network/jlib
LD_LIBRARY_PATH=${ORACLE_HOME}/lib:${ORACLE_HOME}/ctx/lib
ORACLE_OWNER=<ORACLEUSER>
ORACLE_SID=<SID>
ORA_NLS33=${ORACLE_HOME}/ocommon/nls/admin/data
TNS_ADMIN=${ORACLE_HOME}/network/admin
ORACLE_PROCESSES="ora_pmon_${ORACLE_SID} ora_smon_${ORACLE_SID} ora_dbw0_${ORACLE_SID} ora_lgwr_${ORACLE_SID} ora_ckpt_${ORACLE_SID}"

PATH=/usr/bin:/etc:/usr/sbin:/usr/ucb:$HOME/bin:/usr/bin/X11:/sbin:/opt/oracle/product/10.2/bin:.

export PATH CLASSPATH LD_LIBRARY_PATH ORACLE_BASE ORACLE_HOME ORACLE_OWNER ORACLE_SID ORA_NLS33 TNS_ADMIN

case "$1" in

start )
 echo "Starting the Oracle Server"
 su $ORACLE_OWNER -c "${ORACLE_HOME}/bin/dbstart"

 echo "Starting Oracle listener"
 su $ORACLE_OWNER -c "${ORACLE_HOME}/bin/lsnrctl start ${ORACLE_SID}_LISTENER"

 echo "Starting Oracle Enterprise Manager Console in the background"
 su $ORACLE_OWNER -c "$ORACLE_HOME/bin/emctl start dbconsole &"
 ;;

stop )
 echo "Stopping Oracle Enterprise Manager Console"
 su $ORACLE_OWNER -c "$ORACLE_HOME/bin/emctl stop dbconsole"

 echo "Stopping Oracle listener"
 su $ORACLE_OWNER -c "${ORACLE_HOME}/bin/lsnrctl stop ${ORACLE_SID}_LISTENER"

 echo "Stopping the Oracle Server"
 su $ORACLE_OWNER -c "${ORACLE_HOME}/bin/dbshut"
 ;;

status )
 for i in $ORACLE_PROCESSES; do
    unset pid
    pid=`ps -ef|grep $i|grep -v grep|awk '{ print $2 }'`
    if [[ "$pid" = "" ]] then
      echo "Oracle subprocess $i is stopped..."
      exit 0
    else
      echo "Oracle subprocess $i is running using processed $pid"
    fi
  done

  unset pid
  pid=`ps -ef|grep "${ORACLE_HOME}/bin/tnslsnr" |grep -v grep|awk '{ print $2 }'`
  if [[ "$pid" = "" ]] then
    echo "Oracle listener is stopped..."
    exit 0
  else
    echo "Oracle listener is running using processed $pid"
  fi
  exit 1
 ;;

info )
 # Oracle instance information, version, etc...
;;

env )
 $0 status
 if [[ "$?" = "1" ]] then
   for i in $ORACLE_PROCESSES; do
      echo "********* $i *********"
      pid=`ps -ef|grep $i|grep -v grep|awk '{ print $2 }'`
      ps ewww $pid | tr ' ' '\012' | grep = | sort
      echo
      echo
   done
  else
   echo "Oracle server not available, exiting.."
   exit 1
 fi
;;

* )
 echo "Usage: $0 COMMAND"
 echo "---------------------------"
 echo "start    - Starts the Oracle server and listener daemons"
 echo "stop     - Stops the listener and Oracle server daemons"
 echo "status   - Server stopped/started state"
 echo "env      - Shows environment variables set for Oracle Server"
 echo

 exit 1
esac