How can I chain cases in Bash 3.2, which doesn't have `;&`?

Question

I have a bash script that resumes aborted execution with a case statement. It works great with Bash 4 under CentOS 6 but does not work with CentOS 5 because of Bash 3.2.

Is there any programming logic I can use to replace the following with something more "portable"?

last-action=$(cat /tmp/last-action)

case last-action in)
    beginning)
    function1
    ;&
    middle)
    function2
    ;&
    end)
    function3
    ;&
esac

The thing is, wherever task execution stopped it must resume there and execute everything that comes after. For example, if last-action=middle it would execute function2 and then function3. That's where the operator ;& came in handy.

Any clues to do this without a lot of if statements?

Answer 1

I understand that fallthrough is very convenient, but given your example snippet I don't see how

case "${last_action}" in
        beginning)
                function1
                function2
                function3
                ;;
        middle)
                function2
                function3
                ;;
        end)
                function3
                ;;
esac

would add much overhead to your code. It's still prettier than lots of ifs.

However, if your switch is more complex and you want this to be more dynamic, you can do something along the lines of:

#!/bin/bash

function1() { echo 1; }
function2() { echo 2; }
function3() { echo 3; }

last_action=$1

actions_beginning="function1 function2 function3"
actions_middle="function2 function3"
actions_end="function3"

_actions="actions_${last_action}"
for action in ${!_actions}; do
        "${action}"
done

 

$ ./test.sh beginning
1
2
3
$ ./test.sh middle
2
3
$ ./test.sh end
3

EDIT: Just looked at your code on github and I myself would definitely go this route.