Run some commands asynchronously in bash and then make sure to kill the child processes if the user kills the process with CTRL-C (or similar)

async_children_with_cleanup.sh

#!/bin/bash

trap "exit" INT TERM    # Convert INT and TERM to EXIT
trap "kill 0" EXIT      # Kill all children if we receive EXIT

# Run stuff in the background
sleep 3 &
sleep 4 &

# Find child processes and wait for them to finish so this script doesn't
# exit before the children do (otherwise our trap will kill them)
for job in $(jobs -p); do
    wait $job
done

I don't think trap "exit" INT TERM is needed. It suppresses the real exit code causing the script to always exit with success (exit 0).