source: vendor/bash/3.1-p17/tests/trap.tests

# test the trap code

trap 'echo exiting' 0
trap 'echo aborting' 1 2 3 6 15

# make sure a user-specified subshell runs the exit trap, but does not
# inherit the exit trap from a parent shell
( trap 'echo subshell exit' 0; exit 0 )
( exit 0 )

trap

func()
{
        trap 'echo ${FUNCNAME:-$0}[$LINENO] funcdebug' DEBUG
        echo funcdebug line
}

trap 'echo [$LINENO] debug' DEBUG
echo debug line

trap

func

trap

trap 'echo ${FUNCNAME:-$0}[$LINENO] debug' DEBUG
func2()
{
        echo func2debug line
}
declare -ft func2
func2

unset -f func2

trap '' DEBUG

trap

trap - debug

trap

trap - HUP
trap hup
trap '' INT
trap '' int

trap

# exit 0 in exit trap should set exit status
(
set -e
trap 'exit 0' EXIT
false   
echo bad
)
echo $?

# hmmm...should this set the handling to SIG_IGN for children, too?
trap '' USR2
./trap1.sub

# test ERR trap
./trap2.sub

#
# show that setting a trap on SIGCHLD is not disastrous.
#
set -o monitor

trap 'echo caught a child death' SIGCHLD

sleep 7 & sleep 6 & sleep 5 &

wait

trap -p SIGCHLD

# Now reset some of the signals the shell handles specially back to
# their default values (with or without the SIG prefix)
trap - SIGINT QUIT TERM

trap