Shell script has to run until the status value is updated

Shell Programming and Scripting
1

Hi All,

Need some help like how to exit from the script after updating the column in data base.

db2 connect to DB
STATUS=$(db2 "SELECT STATUS FROM XYZ )
echo $STATUS

Initially the status value will be '4' or 'NOT YET RUN'.

The Shell script has to run until the status value is updated with '0' in data base

2

Example forever loop and if status is 0, then break the loop. Case is nice command to use string comparing.

#!/bin/bash
# or ksh
while true
do
      # your db code here
      # after that:
      case "$STATUS" in
            0) break ;;   # break loop
            4) echo "status 4" ;;
            NOT*YET*RUN) echo "status not yet" ;;
            #....
             *)  echo "other status $STATUS" ;;
       esac
       sleep 10  # sleep 10 sec and poll again
done
echo "Done"
1 Like
3

You might want to run db2 -x SELECT ... to get rid of the heading and 1 record(s) selected.

1 Like
4

Thanks hergp. I tried this code but facing some issue.

if i hard code like status=0 or with some other values (4,Not Yet Run) the script is working fine .But if i am pulling the status value from db, every time it is moving in to other status for all the values 0,4, and Not yet run.

Kindly suggest.

5

I am not sure, if I understand you correctly. Do you mean the SQL SELECT statement or the case-construct afterwards? Can you give an example?

1 Like
6

Some thing like this.

If I use Status=0 in the script no issue. It is immediately coming out of the loop because of break condition in the case statement

But if I fetch Status value from DB like below.
Status= db2 " Select Status from X table" then it is returning "Other Status 0" from the case statement which is wrong. It has to immediately come out of the loop. But its not happening

---------- Post updated at 06:47 AM ---------- Previous update was at 06:34 AM ----------

Currently the status value is '0' . But if I ran the below script it is returning "Other Status 0"

while true
do
db2 connect 
STATUS=$(db2 -x "SELECT JOB_STATUS FROM X WHERE NAME='Test1'")
# after that:
case "$STATUS" in
'0') break ;; # break loop
'4') echo "status 4" ;;
'NOT*YET*RUN') echo "Job Running" ;;
#....
*) echo "other status $STATUS" ;;
esac
sleep 10 # sleep 10 sec and poll again
done
echo "Done"
7

Looks like the output of the select statement is not just 0, but something like 0 .

If the status code in the database does not contain blanks, you just could remove the quotes from the case statement

case $STATUS in

which would effectively strip leading and trailing blanks from the status code.

Otherwise change the patterns within the case statement to include optional blanks.

case "$STATUS" in
       *( )0*( )) break ;;
       ...
1 Like
8

Excellent hergp. Script is working exactly what i am expected.
Many Thanks for your help.:slight_smile: