Is there an elegant way to store and evaluate return values in bash scripts?

Question

I have a rather complex series of commands in bash that ends up returning a meaningful exit code. Various places later in the script need to branch conditionally on whether

Answer 1

If you don't care about the exact error code, you could do:

if long_running_command | grep -q trigger_word; then
    success=1
    : success
else
    success=0
    : failure
fi

if ((success)); then
    : success
else
    : failure
fi

Using 0 for false and 1 for true is my preferred way of storing booleans in scripts. if ((flag)) mimics C nicely.

If you do care about the exit code, then you could do:

if long_running_command | grep -q trigger_word; then
    status=0
    : success
else
    status=$?
    : failure
fi

if ((status == 0)); then
    : success
else
    : failure
fi

I prefer an explicit test against 0 rather than using !, which doesn't read right.

(And yes, $? does yield the correct value here.)