Re: bash continues after kill(self, TERM) on reboot

On 3/1/26 2:52 PM, Daniel Villeneuve wrote:
>     Hi,
>     I'm using GNU bash, version 5.1.8(1)-release (x86_64-redhat-linux-gnu),
>     on a CentOS Stream 9 machine.
>     I am unable to understand what I consider an unexpected behavior from a
>     bash script that does the following:
>     - use "set -e"
>     - install an EXIT trap that takes some time to execute
>     - install a TERM trap that just echoes and then re-kills the script
>     with TERM
>     - start a "sleep infinity" process
>     Both traps unset traps for EXIT and TERM on entry.
>     On reboot, the TERM signal is not caught immediately because of the
>     "sleep" subprocess, which
>     is killed and returns an error.  Bash then could start the EXIT trap or
>     handle the TERM signal.
>     What I observe is that it "starts" the EXIT trap but is then
>     immediately interrupted by the TERM signal.

It probably runs the EXIT trap due to the SIGHUP, which is not included
in your testing. I didn't test anything, just looked at the strace
output.

>
>     wait4(-1, [{WIFSIGNALED(s) && WTERMSIG(s) == SIGTERM}], 0, NULL) = 3130
>     --- SIGHUP {si_signo=SIGHUP, si_code=SI_USER, si_pid=1, si_uid=0} ---
>     --- SIGCONT {si_signo=SIGCONT, si_code=SI_USER, si_pid=1, si_uid=0} ---
>     rt_sigreturn({mask=[CHLD]})             = 3130
>     --- SIGTERM {si_signo=SIGTERM, si_code=SI_USER, si_pid=1, si_uid=0} ---

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
		 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    [email protected]    http://tiswww.cwru.edu/~chet/

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