Linux - case command

Question

How to have spaces or tabs in the menu list?

    PS3='Please enter your choice: '
    options=("Option 1" "Option 2" "Quit")
    select opt in "${options[@]}"
    do
      case $opt in
         "Option 1")
            echo "Your choise is 1"
            ;;
         "Option 2")
            echo "Your choise is 2"
            ;;
         "Quit")
            break
            ;;
         *) echo "Invalid option;;
      esac
    done

And I got this:

[user@Server:/home/user] ./test.sh
1) Option 1
2) Option 2
3) Option 3
4) Quit
Please enter your choice:

But I'd like something like this:

[user@Server:/home/user] ./test.sh
   1) Option 1
   2) Option 2
   3) Option 3
   4) Quit
Please enter your choice:

Ideas?

This has nothing to do with the case statement. It's the select that displays the menu. As an aside note: If you use case $REPLY in, you can test on the numbers instead. That way you don't have to repeat all those strings. — Kusalananda
– Kusalananda ♦, Commented Dec 12, 2018 at 6:36

ilkkachu · Accepted Answer · 2018-12-12 22:29:32Z

It's not too hard to (roughly) reimplement select manually and fine-tune the display, at least as long as you don't have so many options to need a multi-column listing.

#!/bin/bash

# print the prompt from $1, and a menu of the other arguments
choose() {
    local prompt=$1
    shift
    local i=0
    for opt in "$@"; do
        # we have to do the numbering manually...
        printf "  %2d) %s\n" "$((i += 1))" "$opt"
    done
    read -p "$prompt: "
}

options=("Foo" "Bar" "Quit")
while choose 'Please enter your choice'  "${options[@]}"; do
    case $REPLY in
    1) echo "you chose 'foo'" ;;
    2) echo "you chose 'bar'";;
    3) echo 'you chose to quit'; break;;
    *) echo 'invalid choice';;
    esac
done

Of course, this could be extended to take the array keys (indices) into account, and to present them as the choices in the menu, instead of a running counter.

Kusalananda · Accepted Answer · 2018-12-12 08:20:28Z

The select statement in bash, which is what displays the menu, does not allow specifying an indent for the menu.

Just a comment on the code: It's usually easier to let the case statement act on $REPLY rather than the variable with the selected string. It saves you from having to type in the strings twice.

E.g.

select opt in "${options[@]}"
do
  case $REPLY in
     1)
        echo "Your choice is 1"
        ;;
     2)
        echo "Your choice is 2"
        ;;
     3)
        break
        ;;
     *) echo 'Invalid option' >&2
  esac
done

or, for this specific example,

select opt in "${options[@]}"
do
  case $REPLY in
     [1-2])
        printf 'Your choice is %s\n' "$REPLY"
        ;;
     3)
        break
        ;;
     *) echo 'Invalid option' >&2
  esac
done

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