#           This shell script takes care of starting and stopping
#              the Pen load balancer
#

PID_FILE=run.pid
OUT=run.out

# resolve all links
readlink() {
    file="$1"

    while [ -h "$file" ] ; do
        link="`\ls -ld "$file" | tail -1 | sed 's/.* -> //'`"
        # resolve relative links - in bash we could use the simpler:
        #[[ "$link" != /* && "$file" == */* ]] && file="${file%/*}/$link" || file="$link"
        case "$link" in
            /*) file="$link" ;;
            *)
                case "$file" in
                    */*) file="`echo ${file} | sed 's/[^/]*$//'`$link" ;;
                    *)   file="$link" ;;
                esac
                ;;
        esac
    done

    echo "$file"
}

is_running() {
    [ -r "$PID_FILE" ] && pid=`cat $PID_FILE`
    [ -n "$pid" -a -r "/proc/$pid" ] && return 0 || return 1
}

start() {
    rm -f "$OUT"
    pen 80 luna1:80 sol3:80 "$@" > $OUT
    sleep 1
    ps -ef | grep pen | cat -n | grep "     1" | awk '{print $3}' > $PID_FILE
    echo "Server started."
    echo "  See $OUT for startup message (normally there are none)."
    echo "  See $PID_FILE for PID. `cat $PID_FILE`"
}

stop() {
    if is_running ; then : ; else
        echo "Server not running"
        return
    fi

    kill $pid
    while [ -r "/proc/$pid" ] ; do sleep 1 ; done
    rm -f $PID_FILE
    echo "Server stopped"
}

ME="`readlink "$0"`"
cd "`dirname \"$ME\"`"

case "$1" in
    start)
        if is_running ; then
            echo "Server already running, pid $pid"
            exit 1
        fi
        shift
        start "$@"
        ;;

    stop)
        stop
        ;;

    restart)
        shift
        stop
        start "$@"
        ;;

    status)
        if is_running ; then
            echo "Server running, pid $pid"
        else
            echo "Server not running"
        fi
        ;;

    *)
        echo "Usage: $0 {start|stop|restart|status}"
        exit 1
        ;;

esac