Shell Programming and Scripting

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:

Code:

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!

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

Fixed it!

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

Code:

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:

Code:

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.....

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.