The following Bash loop stops if I interrupt it with
(while true; do sleep 5; done)
The following, however, does not:
(while true; do aplay test.wav; done)
The difference, from what I can tell, is that
aplay catches and handles
sleep does not.
Why is this? Does POSIX specify this behavior somewhere (I notice that Dash does the same thing), and if so, why? I cannot quite understand why this behavior is desirable. In fact, how can Bash even tell the difference? I must admit I'm not aware of any mechanism (other than
/proc/ hacking, at least) by which one process can tell how another one handles signals.
Also, is there a way to counteract it? I notice that not even a
trap 'exit 0' SIGINT before the loop helps.
(EDIT: Running the loops in a subshell is important, because otherwise the parent shell does not receive the