Multiple while statements?

Shell Programming and Scripting
1

I'm working on a script for class as a final project. We have to ask for values (city, state, zip) five times, but the state can only be MI, IN, IL, or OH. I'm trying to do this with a while loop inside of a while loop, but I have no idea how to do it properly.

Here's what I have so far:

COUNT=0
while [ "$COUNT" -lt "5" ]; do
  clear
  echo "Enter City: "; read CITY
  echo "Enter State: "; read STATE
        while [[ "$STATE" != "MI" && "$STATE" != "IN" && "$STATE" != "IL" && "$STATE" != "OH" ]]; do
          echo "Sorry, that's not an accepted state."; read STATE
        done
  echo "Enter Zip: "; read ZIP
COUNT="$COUNT"+1
done
sleep 5

I have a feeling I'm way off... and I have no idea how to fix it.

Help is appreciated!

2

Actually, you are pretty close. Inside the while that validates the state, just prompt for the state again.

3

Fixed it!

My syntax for the while loop that checked STATE was bad. In bash, you have to use -a instead of &&:

while [ "$STATE" != "MI" -a "$STATE" != "OH" -a "$STATE" != "IL" -a "$STATE" != "IN" ];do
   echo "Sorry, that's not an accepted state."
   echo "Enter State: "; read STATE
done

And for some reason, my bash won't recognize the let command... so I have to use expr instead for a counter:

COUNT=0
while [ "$COUNT" -le "5" ]; do
  echo "Count is less than 5."
  COUNT=`expr $COUNT + 1`
done

The wonders of a good night's sleep.....

4

Actually, using && within double square brackets is correct. The single open square bracket (actually the test command) does not support double ampers and as you have noticed it does need -a. This is a test command syntax requirement, not bash; most people don't realise that the [ is a command and not a shell built-in.

Using test (or [) is less efficient than using the shell (bash or Kshell) built-in [[. There are times where using test makes sense, but for most scripts I believe that the built-in is best.

I just had a look at your original script and didn't notice that you were issuing the read before your echo "try again." Other than that, it works for me.