Shell Programming and Scripting

Hello,

I have HP-UX 11 at work.
Below is a part of the script I'm writing. User gets prompted to enter environment type. The While loop checks if the entered value is either P or D.
If neither of two is entered, then the scripts prompts to enter the value again.
- If correct environment type is passed, it still enters the infinite loop
- If incorrect environment type is passed, I get prompted to re-enter. Upon entering the correct value, I'm still in the infinite loop.

Please help.

Thank you.

1 #!/bin/ksh
2
3 echo "Please enter environment type:"
4 read environment
5
6 while [ $environment != "P" ] || [ $environment != "D" ]
7 do
8 echo "Invalid environment entered. Please enter environment type again:"
9 read environment
10 done
11 echo $environment

Try using && instead of ||. With ||, it will keep looping if either of those statements is false, and since they can never both be true at the same time, this causes an infinite loop. && only keeps the loop going when they are BOTH false, if one is true then the loop will break.

Thank you.

That worked. I was under impression to have OR and not AND.
But, now I understand that the AND here does not mean they both have to be true, but And means that we need to test more than one variable (in this case same variable being tested twice).

Thanks again