A Bourne Shell script that will run a command in the background and will send it a SIGTERM when it is received

background.sh

#!/bin/sh
#
# The script demonstrates how to terminate a background process. It will run
# the process and wait till a SIGTERM signal is received, then it will pass that
# along to the background process and return its status.
#
# Syntax: background.sh command-line
#
pid=0


# SIGTERM-handler
term_handler() {
  if [ $pid -ne 0 ]; then
    kill -TERM "$pid"
    wait "$pid"
    exit $?
  fi
}

# setup handlers
# on callback, kill the last background process, which is `tail -f /dev/null` and execute the specified handler
trap 'kill ${!}; term_handler' TERM

# run application that was passed as arguments to the script
$@ &
pid="$!"

# wait forever
while true
do
  tail -f /dev/null & wait ${!}
done