2014马哥Linux0218-4中script.sh的题目

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