sqlplus interprets $

When using a ksh script with sqlplus -s

trying to find file systems low on space.

sqlplus -s sysm***/****@o**9 >$filedir/plus.out << .eof
set feedback off
set pages 999
set echo on
set long 999999
set trimspool on
set newpage none
spool $fs_full
select target_name, metric_name, column_label,key_value, value||'%', collection_timestamp
from sysman.MGMT$METRIC_CURRENT
where target_type='host' and target_name like 'dbehst***%' --order by 1
and metric_name='Filesystems'
and metric_column='pctAvailable'
and value < 5;

METRIC_CURRENT: parameter not set

{data masked by moderator}