How to get the exit status a loop in bash

Question

I know how to check the status of the previously executed command using $?, and we can make that status using exit command. But for the loops in bash are always returning a

Answer 1

Git 2.27 (Q2 2020), offers a good illustration of the exit status in a loop, here within the context of aborting a failing test early (e.g. by exiting a loop), which is to say "return 1".

See commit 7cc112d (27 Mar 2020) by Junio C Hamano (gitster).
^{(Merged by Junio C Hamano -- gitster -- in commit b07c721, 28 Apr 2020)}

t/README: suggest how to leave test early with failure

^{Helped-by: Jeff King}

Over time, we added the support to our test framework to make it easy to leave a test early with failure, but it was not clearly documented in t/README to help developers writing new tests.

The documentation now includes:

Be careful when you loop

You may need to verify multiple things in a loop, but the following does not work correctly:

test_expect_success 'test three things' '
    for i in one two three
    do
      test_something "$i"
    done &&
    test_something_else
'

Because the status of the loop itself is the exit status of the test_something in the last round, the loop does not fail when "test_something" for "one" or "two" fails.
This is not what you want.

Instead, you can break out of the loop immediately when you see a failure.
Because all test_expect_* snippets are executed inside a function, "return 1" can be used to fail the test immediately upon a failure:

test_expect_success 'test three things' '
    for i in one two three
    do
      test_something "$i" || return 1
    done &&
    test_something_else
'

Note that we still &&-chain the loop to propagate failures from earlier commands.