foo() {
    true | while true; do
        false
        rc=$?
        if [ $rc -eq 1 ]; then
            return 1
        fi
    done
    echo $?
    return 0
}
 
foo || echo "Failed foo"

Run it and see. I suspect everyone but the script gurus out there will be surprised.

What about this script then?

bar () {
    local rc=0
    true | while true; do
        false
        rc=$?
        if [ $rc -eq 1 ]; then
            return 1
        fi
    done
    echo $?
    echo $rc
    return 0
}
 
bar

Surprised again?

I guess this means that scoping in bash is somewhat more complicated then I would have ever guessed.

More »

1. The script is somewhat artificial, who would ever use the construct true | while ...? I’ve used this just to show the point while keeping the examples short. Feel free to replace that part with something more useful, like cat myfile | while read ....