这道题目虽然不是很难，但是如果编程不熟练的话，还是有些挑战的。在这里感谢我搜索到的这位朋友，他的解题代码给我很大的参考，他的blog是：http://sohudrgon.blog.51cto.com/3088108/1586780/
写一个脚本，完成如下任务，其使用形式如下所示：
script.sh {start|stop|restart|status}
其中：
如果参数为空，则显示帮助信息，并退出脚本；
如果参数为start，则创建文件/var/lock/subsys/script，并显示“starting script successfully.”
如果参数为stop，则删除文件/var/lock/subsys/script，并显示“stop script successfully.”
如果参数为restart，则删除文件/var/lock/subsys/script并重新创建，而后显示“Restarting script successfully.”
如果参数为status，那么：
如果文件/var/lock/subsys/script存在，则显示“Script is running...”，否则则显示“Script is stopped.”
#!/bin/bash
#
shName=`basename $0`
fileName="/var/lock/subsys/$shName"
if [ $# -ne 1 ];then
echo "Usage:$shName {start|stop|restart|status}"
echo "Please try again."
exit 3
fi
if [ "$1" == "start" ];then
if ! [ -e $fileName ];then
touch $fileName && echo "Starting $fileName successfully."
else
echo "$fileName already exists, try again." && exit 4
fi
elif [ "$1" == "stop" ];then
if [ -e $fileName ];then
rm -fv $fileName && echo "Stop $fileName successfully."
else
echo "$fileName does not exist, try again." && exit 4
fi
elif [ "$1" == "restart" ];then
if [ -e $fileName ];then
rm -fv $fileName
touch $fileName && echo "Restarting $fileName successfully."
else
touch $fileName
echo "Restarting $fileName successfully."
fi
elif [ "$1" == "status" ];then
if [ -e $fileName ];then
echo "$shName is running."
else
echo "$shName is stopped."
fi
else
echo "Usage:$shName {start|stop|restart|status}"
echo "Please try again."
exit 3
fi