how to passing variable from bash to sqlplus - linux

Question

I have below code in bash:
#/!bin/bash
USERS=tom1,tom2,tom3
and I want to drop all users from my variable "USERS" via sqlplus
#/!bin/bash
USERS=tom1,tom2,tom3
sqlplus -s system/*** <<EOF
*some code*
DROP USER tom1 CASCADE;
DROP USER tom2 CASCADE;
DROP USER tom2 CASCADE;
EOF
pls help

Answer 1

Splitting in database using sql / plsql by using the USERS variable is complex and requires understanding of REGEXP functions and I will not recommend that to you. Moreover, it would also require Dynamic Sql to execute a drop query.
I would suggest you to split it within the shell script,create a script and execute it in sqlplus
USERS="tom1,tom2,tom3"
echo ${USERS} | tr ',' '\n' | while read word; do
echo "drop user $word;"
done >drop_users.sql
sqlplus -s system/pwd <<EOF
#some code
#drop_users.sql
EOF

Answer 2

Your code is OK except for DDL commands for Oracle DB which are derived from USERS parameter of the script file, call userDrop.sh. To make suitable relation with USERS parameter and DB, an extra file (drpUsr.sql) should be produced, and invoked inside EOF tags with an # sign prefixing.
Let's edit by vi command :
$ vi userDrop.sh
#!/bin/bash
USERS=tom1,tom2,tom3
IFS=',' read -ra usr <<< "$USERS" #--here IFS(internal field separator) is ','
for i in "${usr[#]}"; do
echo "drop user "$i" cascade;"
done > drpUsr.sql
#--to drop a user a privileged user sys or system needed.
sqlplus / as sysdba <<EOF
#drpUsr.sql;
exit;
EOF
Call as
$ . userDrop.sh
and do not forget to come back to command prompt by an exit command of DB.