: ${TMPDIR:=/var/tmp}
TMPFILE=$TMPDIR/exitcode

rm -f $TMPFILE
set -e
exit_handler() { echo "exit code: $?" ; touch $TMPFILE; }
false() { ! :; }
notfound() { nosuchcommand ; }
syntaxerror() { !:; }

main()
{(
    trap exit_handler 0
    "$@" >> /dev/null 2>&1
)}
main "$@"
echo "after main: should not get here"