#!/bin/bash

PIDFILE="/var/run/whatever.pid"

start() {
        # If PID file exists, it can be read, the contents aren't blank, and the process still exists,
        # it's already running.
        if [ -f $PIDFILE ] && read PID < $PIDFILE && [ ! -z "$PID" ] && [ -d /proc/$PID ]
        then
                echo "Already started" >&2
                exit 0
        fi

        echo "starting whatever..." >&2
        nohup whatever & disown
        echo "$!" > $PIDFILE
        echo "started whatever" >&2
}

stop() {
        if [ -f $PIDFILE ] && read PID < $PIDFILE && [ ! -z "$PID" ] && [ -d /proc/$PID ]
        then
                echo "stopping whatever"
                # Give it a polite SIGINT
                kill -INT $PID
                sleep 1

                # If it doesn't die, give it higher signals until it does
                for SIG in QUIT TERM 9
                do
                        [ -d /proc/$PID ] || break
                        kill -$SIG $PID
                        sleep 2
                done

                if [ -d /proc/$PID ]
                then
                        echo "Couldn't stop whatever" >&2
                        return 1
                fi

                echo "stopped whatever" >&2
                return 0
        else
                echo "whatever not started" >&2
                exit 1
        fi
}

case "$1" in
start)  start   ;;
stop)   stop    ;;
*)       echo "unknown option" >&2 ; false ;;
esac

exit $?