I have the following script I need to exit the look when 1hr expires or the sql statemnt comes back successfully (i.e. return 0) It seams my variable $CTR is not incrementing and I'm not sure why. Any help is appriciated

#! /usr/bin/ksh
CTR=0
RC=10
while [ $CTR -ne 6 -o $RC -ne 0 ]; do
let "$CTR = $CTR + 1"
echo $CTR
sqlplus -s $USER/$PW@$SID @ndm_file_check.sql stmt1
RC=$?
if [ $RC -ne 0 ]
then
sleep 600
fi
done

exit 0

loose the quotes and the '$'-s....

let "$CTR = $CTR + 1"

You should not use dollar signs with let and you must not use a dollar sign with the lvalue.

let "CTR=CTR+1"

and rather than let, the double parentheses notation is better, although "let" is not actually incorrect.

((CTR=CTR+1))