#!/bin/bash
export MYSHLVL=${MYSHLVL:-$SHLVL}
if [ .${MYSHLVL}. = .${SHLVL}. ]
then   # force run bash script
echo run script by bash L$MYSHLVL L$SHLVL
echo "$BASH_SOURCE $@"
bash $BASH_SOURCE $@
else   # script body
echo "script body L$MYSHLVL L$SHLVL"
echo "cmd: $0"
for i in $@
do
  echo "arg: $i"
done
export PASS=secret
echo $1 $2 $PASS
exit
fi
check environment variable after execution
set | grep secret

$ bash $PWD/ttt.sh p1 p2 p3
script body L1 L2
cmd: /home/oracle/tmp/ttt.sh
arg: p1
arg: p2
arg: p3
p1 p2 secret
$ $PWD/ttt.sh p1 p2 p3
script body L1 L2
cmd: /home/oracle/tmp/ttt.sh
arg: p1
arg: p2
arg: p3
p1 p2 secret
$ source $PWD/ttt.sh p1 p2 p3
run script by bash L1 L1
/home/oracle/tmp/ttt.sh p1 p2 p3
script body L1 L2
cmd: /home/oracle/tmp/ttt.sh
arg: p1
arg: p2
arg: p3
p1 p2 secret
$ source ttt.sh
run script by bash L1 L1
ttt.sh
script body L1 L2
cmd: ttt.sh
secret

SQL> show parameters prefix

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
os_authent_prefix                    string      ops$
SQL> create user ops$oracle identified externally;

User created.

SQL> grant create session to ops$oracle;

Grant succeeded.

$ id
uid=54321(oracle) gid=54321(oinstall) groups=54321(oinstall),54322(dba)
$ echo show user | sqlplus -l -s / as sysdba
USER is "SYS"
$ echo show user | sqlplus -l -s /
USER is "OPS$ORACLE"