ctrl+c not sending SIGKILL to process

Question

I have tried implementing this function:

void alarm_handler(int signal)
{
    if(signal==SIGKILL)
    {
        fprintf(stderr,"Process killed\n");
        exit(SIGKILL);
    }
}

And used it in main this way:

signal(SIGKILL,alarm_handler);

So if I press ctrl+c, before exiting it shall print "Process killed", but id does not print it.Why?

And furthermore, SIGKILL cannot be caught ( http://en.wikipedia.org/wiki/SIGKILL ). — Clement Bellot, Mar 28 '12 at 09:32

score 14 · Answer 1 · answered Mar 28 '12 at 09:26

14

Ctrl+C usually sends SIGINT, not SIGKILL.

answered Mar 28 '12 at 09:26

orlp

Not usually, but always (unless you configure the terminal tty in very weird ways) is Ctrl-C sending `SIGINT` – Basile Starynkevitch Mar 28 '12 at 20:14
1

@Basile Starynkevitch: I didn't want to exclude the possibility of a weird terminal. It is possible to write one / configure one that sends `SIGKILL` instead of `SIGINT` :) – orlp Mar 29 '12 at 07:17

score 3 · Answer 2 · answered Mar 28 '12 at 09:31

3

The signals SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.

Use SIGINT.

answered Mar 28 '12 at 09:31

Vodun

2 Answers2