ctrl+c to kill a bash script with child processes

Question

I have a script whose internals boil down to:

trap "exit" SIGINT SIGTERM
while :
do
    mplayer sound.mp3
    sleep 3
done

(yes, it is a bit more meaningful than the above, but that's not relevant to the problem). Several instances of the script may be running at the same time.

Sometimes I want to ^C the script... but that does not succeed. As I understand, when ^C kills mplayer, it continues to sleep, and when ^C kills sleep, it continues to mplayer, and I never happen to catch it in between. As I understand, trap just never works.

How do I terminate the script?

Answer 1

You can get the PID of mplayer and upon trapping send the kill signal to mplayer's PID.

function clean_up {

    # Perform program exit housekeeping
    KILL $MPLAYER_PID
    exit
}

trap clean_up SIGHUP SIGINT SIGTERM
mplayer sound.mp3 &
MPLAYER_PID=$!
wait $MPLAYER_PID