Calling PL/SQL Package in Unix Shell Script

#!/usr/bin/sh
echo "XXSCRIPT Version 1.0";
echo '================================='
echo '==Calling PL/SQL Package in Unix ========'
echo '================================='

sqlplus -s $1 <<-EOF
exec XX_PKG.procedure;
exit
EOF

retcode=`echo $?`
echo 'Return Code is => '  ${retcode}
if [ ${retcode} -ne 0 ];
   then
   exit 1;
fi
exit 0;