linux sh启动jar包

#!/bin/sh
now='date + %Y%m%d'
command='java -jar -Xmx2048m -Xms1024m -Xss512 testgetpid.jar'
log_file="log/${now}.log"
start(){
    if [ $log_file =! "" ]; then
        exec $command >> $log_file &
    else
        exec $command &
    fi
}
stop(){
    ps -ef | grep "$command" | awk '{print $2}' | while read pid
    do
        C_OID=$(ps --no-heading $pid | wc -1)
        echo "current PID = $pid"
        if [ "$C_OID" == "1" ];then
            echo "PID = $pid ready to finish!"
            kill -9 $pid
            echo "PID = $pid is over!"
        else
            echo "PID = $pid non-existent!"
        fi
    done
}
case "$1" in
        start)
                start
        ;;
        stop)
                stop
        ;;
        restart)
                stop
                start
        ;;
        *)
printf 'Usage : %s {start|stop|restart}\n' "$prog"
exit 1
;;
esac