#!/bin/bash
set -e
set -o pipefail

function echoTraps() {
    echo "= on start:"
    trap -p
    trap -- 'echo func-EXIT' EXIT
    echo "= after set new:"
    trap -p
    # we can ensure after script done - file '/tmp/tmp.txt' was not created
    trap -- 'echo SIG 1>/tmp/tmp.txt' SIGPIPE SIGHUP SIGINT SIGQUIT SIGTERM
}

trap -- 'echo main-EXIT1' EXIT

echo "===== subshell trap"
( echoTraps; )

echo "===== pipe trap"
echoTraps | cat

echo "===== done everything"