How to debug a script by removing the "if"?

Question

I have the following code:

debug=$?
function a {
    su - javi -c "uptime"
    return $debug
}

function b {
    su - javi -c "cat /etc/redhat-release"
    return $debug
}

function c {
    su - javi -c "cat /etc/redhat-release"
    return $debug
}

case $debug in
0)
    a
    if [ $debug == 0 ]; then
        b
        echo "se ejcuta la funcion"
    elif [ $debug == 0 ]
        c   
    elif[].... <-----this

    fi
;;

1)
    echo "se ha producido un error"
;;

esac

Is there any way to debug by removing the if ??I want them to go running a function if it ends well that jumps to the other function and if it does not end well that it leaves the escript, that with 5 functions

Answer 1

If the goal is simply to run each function, and bail out of there was any errors, maybe something like this will work:

function bail {
    echo "se ha producido un error ($1)"
    exit 1
}

function a {
    uptime
}

function b {
    cat /etc/redhat-release
}

function c { 
    cat /etc/redhat-release
}

for f in 'a' 'b' 'c'; do
    $f || bail "$f: $?"
done

This will run each function, and if an error is encountered, the function name and exit code are sent to the bail function, which will print a line and bail out of any additional commands.

I did remove the use of su because it was easier to test that way. If you want to automate this, I'd recommend creating a sudo profile to run those commands with elevated privileges in such a way that you only need to enter your password once, or no times at all.

Answer 2

1. debug=$? is not evaluated at every command. So the value of debug will be the same throughout the entire script.
2. The return code of a function is the return code of its last command. So the return statements are pointless.

In summary, something like a && b && c will run b if a succeeds, and will run c if b succeeds. The return code of this compound command is the first non-zero return code of each of the functions.