Bash script: always show menu after loop execution

问题:

I'm using a bash script menu like this:

#!/bin/bash
PS3='Please enter your choice: '
options=("Option 1" "Option 2" "Option3" "Quit")
select opt in "${options[@]}"
do
    case $opt in
        "Option 1")
            echo "you chose choice 1"
            ;;
        "Option 2")
            echo "you chose choice 2"
            ;;
        "Option 3")
            echo "you chose choice 3"
            ;;
        "Quit")
            break
            ;;
        *) echo invalid option;;
    esac
done

After each menu selection I just get prompted with

Please enter your choice:

How do I always show the menu after each option has finished execution? I've done some looking around and I think I can do some kind of while loop, but I haven't been able to get anything working.

回答1:

Make it beautiful and userfriendly ;-)

#!/bin/bash

while :
do
    clear
    cat<<EOF
    ==============================
    Menusystem experiment
    ------------------------------
    Please enter your choice:

    Option (1)
    Option (2)
    Option (3)
           (Q)uit
    ------------------------------
EOF
    read -n1 -s
    case "$REPLY" in
    "1")  echo "you chose choice 1" ;;
    "2")  echo "you chose choice 2" ;;
    "3")  echo "you chose choice 3" ;;
    "Q")  exit                      ;;
    "q")  echo "case sensitive!!"   ;; 
     * )  echo "invalid option"     ;;
    esac
    sleep 1
done

Replace the echos in this example with function calls or calls to other scripts.

回答2:

just modified your script like below. its working for me !

 #!/bin/bash
 while true
 do
 PS3='Please enter your choice: '
 options=("Option 1" "Option 2" "Option 3" "Quit")
 select opt in "${options[@]}" 
 do
     case $opt in
         "Option 1")
             echo "you chose choice 1"
             break
             ;;
         "Option 2")
             echo "you chose choice 2"
             break
             ;;
         "Option 3")
             echo "you chose choice 3"
             break
             ;;
         "Quit")
             echo "Thank You..."                 
             exit
             ;;
         *) echo invalid option;;
     esac
 done
 done

回答3:

You can also do something like:

#!/bin/bash

PS3='Please enter your choice: '
options=("Option 1" "Option 2" "Option 3" "Quit")
select opt in "${options[@]}"
do
    case $opt in
        "Option 1")
            echo "you chose choice 1"
            ;;
        "Option 2")
            echo "you chose choice 2"
            ;;
        "Option 3")
            echo "you chose choice 3"
            ;;
        "Quit")
            break
            ;;
        *) echo invalid option;;
    esac
    counter=1
    SAVEIFS=$IFS
    IFS=$(echo -en "\n\b")   # we set another delimiter, see also: https://www.cyberciti.biz/tips/handling-filenames-with-spaces-in-bash.html
    for i in ${options[@]};
    do
        echo $counter')' $i
        let 'counter+=1'
    done
    IFS=$SAVEIFS
done