linux - 减号操作错误

Question

我的脚本如下:

for i in {"CON","PA","PRO","RE","S","UN","VO"};
do
count=$(sqlplus -S $user/$pass<<EOF
    select count(distinct s.filename) as count
    from cd.tbl_1 s
    where s.dt like to_char(sysdate-1,'YYYYMMDD')||'%' and s.type='$i';
    exit;
    EOF)
yday=$(date --date="yesterday" +"%b %_d")
thecount=$(ls . -ltr | grep "$yday" | wc -l)
echo $i" ON DB  $count DB files is lower than the number $((thecount-count)) files in folder
     ------------------------------------------------------------------------------------";

但有趣的是 $thecount 和 $count 的值完全相同，所以当我像上面那样使用减号运算时，它没有 0 值和不同的值。所以它不减正确。这里有什么问题？

Answer 1

I found my mistake, 

count=$(sqlplus -S $user/$pass<<EOF
    select count(distinct s.filename) as count
    from cd.tbl_1 s
    where s.dt like to_char(sysdate-1,'YYYYMMDD')||'%' and s.type='$i';
    exit;
    EOF)

this part is printing non-numeric values which is like below

COUNT ---------- 5663

that's why cannot any operation on those numbers. 

So how do i select only numbers "5663" ?