Bash Shell脚本:嵌套选择语句

Question

我有一个脚本,有一个Select语句去多个子选择语句但是一旦我在那里我似乎无法弄清楚如何让它回到主脚本.如果可能的话,我希望它重新列出选项

  #!/bin/bash
           PS3='Option = '
           MAINOPTIONS="Apache Postfix Dovecot All Quit"
           APACHEOPTIONS="Restart Start Stop Status"
           POSTFIXOPTIONS="Restart Start Stop Status"
           DOVECOTOPTIONS="Restart Start Stop Status"
           select opt in $MAINOPTIONS; do
               if [ "$opt" = "Quit" ]; then
               echo Now Exiting
               exit
               elif [ "$opt" = "Apache" ]; then
                 select opt in $APACHEOPTIONS; do
                 if [ "$opt" = "Restart" ]; then
                 sudo /etc/init.d/apache2 restart
                 elif [ "$opt" = "Start" ]; then
                 sudo /etc/init.d/apache2 start
                 elif [ "$opt" = "Stop" ]; then
                 sudo /etc/init.d/apache2 stop
                 elif [ "$opt" = "Status" ]; then
                 sudo /etc/init.d/apache2 status
                 fi
                 done
               elif [ "$opt" = "Postfix" ]; then
                 select opt in $POSTFIXOPTIONS; do
                 if [ "$opt" = "Restart" ]; then
                 sudo /etc/init.d/postfix restart
                 elif [ "$opt" = "Start" ]; then
                 sudo /etc/init.d/postfix start
                 elif [ "$opt" = "Stop" ]; then
                 sudo /etc/init.d/postfix stop
                 elif [ "$opt" = "Status" ]; then
                 sudo /etc/init.d/postfix status
                 fi
                 done
               elif [ "$opt" = "Dovecot" ]; then
                 select opt in $DOVECOTOPTIONS; do
                 if [ "$opt" = "Restart" ]; then
                 sudo /etc/init.d/dovecot restart
                 elif [ "$opt" = "Start" ]; then
                 sudo /etc/init.d/dovecot start
                 elif [ "$opt" = "Stop" ]; then
                 sudo /etc/init.d/dovecot stop
                 elif [ "$opt" = "Status" ]; then
                 sudo /etc/init.d/dovecot status
                 fi
                 done
                 elif [ "$opt" = "All" ]; then
                 sudo /etc/init.d/apache2 restart
                 sudo /etc/init.d/postfix restart
                 sudo /etc/init.d/dovecot restart
               fi
               done

Answer 1

您通常会case在select语句中嵌套语句并将整个事物放在循环中:

while true
do
    select option in $options
    do
        case $option in
            choice1)
                do_something
                ;;
            choice2)
                select sub_option in $sub_options
                do
                    case $sub_option in
                        sub_choice1)
                            another_thing
                            ;;
                        sub_choice2)
                            break    # return to current (sub) menu
                            ;;
                        sub_choice3)
                            break 2  # return to parent menu
                            ;;
                     esac
            choice3)
                 break    # return to current (main) menu
                 ;;
            choice4)
                 break 2  # exit the while loop so cleanup can be done at the end of the script
        esac
    done
done
do_cleanup