running SQL plus from UNIX

[bensr]

Try something like this:
sqlplus ${OP_CONNECT_STRING}@${OP_ORA_INST} @sqls/sel_logical_dt.sql > logical_dt.log

rc=$?

if [ $rc -eq 0 ]
then
ANSWER=`cat logical_dt.log`
else
# In this case there will be an error
ANSWER=""
fi
echo $ANSWER

==============================
Don't forget in your sql:
set heading off
set pagesize 0
set feedback off
set verify off
set termout off
set timing off
set wrap on
WHENEVER SQLERROR EXIT SQL.SQLCODE

==============================
Without error-detection:
ANSWER=`sqlplus ${OP_CONNECT_STRING}@${OP_ORA_INST} @sqls/sel_logical_dt.sql`