Get my Coffee, Compass and web server in the background, please

tools.sh

#!/bin/bash

stop()
{
  echo "Shutting down..."

  if [[ $SERVER_PID ]]; then kill -HUP $SERVER_PID; fi;
  if [[ $COMPASS_PID ]]; then kill -HUP $COMPASS_PID; fi;
  if [[ $COFFEE_PID ]]; then kill -HUP $COFFEE_PID; fi;

  if [ -f .coffee.pid ]; then rm -f .coffee.pid; fi;
  if [ -f .compass.pid ]; then rm -f .compass.pid; fi;
  if [ -f .server.pid ]; then rm -f .server.pid; fi;

  trap - INT

  echo "Done."
  exit
}

if [ "$1" == "start" ]; then

  COFFEE_PID=0
  COMPASS_PID=0
  SERVER_PID=0

  trap stop INT

  echo "Starting processes..."

  coffee --watch --compile --output static/lib src &
  COFFEE_PID=$!

  compass watch --config compass.config.rb --sass-dir src/styles --css-dir static/styles &
  COMPASS_PID=$!

  python -m SimpleHTTPServer &
  SERVER_PID=$!

  echo $COFFEE_PID > .coffee.pid
  echo $COMPASS_PID > .compass.pid
  echo $SERVER_PID > .server.pid

  echo "Use '$0 stop' to kill."

elif [ "$1" == "stop" ]; then

  if [ -f .coffee.pid ]; then read COFFEE_PID < .coffee.pid; fi;
  if [ -f .compass.pid ]; then read COMPASS_PID < .compass.pid; fi;
  if [ -f .server.pid ]; then read SERVER_PID < .server.pid; fi;

  stop

else

  echo "Usage: $0 [start,stop]"

fi