How do I write an IF statement with multiple conditions on the same line in Bash?

I'm writing a script right now in Bash that will execute two SQL queries and analyze that queried data. One of the command line inputs takes in an environment variable, which can be one of three values. If it's not one of those values, the script displays a message that prompts the user to enter in a correct value. However, the script doesn't properly check the value, instead prompting the user. Here is my code:

if [[ -z $ENV1 || $ENV1 != "ITF" || $ENV1 != "Prod" || $ENV1 != "QA" ]]
then
    read -rp "Please ente开发者_如何转开发r the first environment (ITF, Prod, QA): " ENV1
fi
echo $ENV1

I think it's a problem with having multiple ||'s in the if line. How can I go about checking for all for of those conditions?

It looks to be a problem with your condition. Even if ENV1 is any of your options, one of the conditions will be true. For example, ENV1 could be "QA", but ENV1 != "Prod" will still evaluate to true (0). Instead of || use &&:

if [[ -z $ENV1 || ($ENV1 != "ITF" && $ENV1 != "Prod" && $ENV1 != "QA") ]]
then
    read -rp "Please enter the first environment (ITF, Prod, QA): " ENV1
fi
echo $ENV1

Consider using case instead, it will make the code clearer:

case $ENV1 in
    "ITF" | "Prod" | "QA")
        echo using $ENV1
        ;;
    "")
        read -rp "Please enter the first environment (ITF, Prod, QA): " ENV1
        ;;
    *)
        echo $ENV1 is not valid
        read -rp "Please enter the first environment (ITF, Prod, QA): " ENV1
        ;;
 esac

This is a good time to use select:

select ENV1 in ITF Prod QA; do 
  case "$ENV1" in 
    ITF|Prod|QA) break;; 
  esac
done

Not so DRY though.

DRYer version

envs=( ITF Prod QA )
select ENV1 in "${envs[@]}"; do 
  for e in "${envs[@]}"; do 
    [[ $ENV1 == $e ]] && break 2
  done
done