二十、编写简单脚本之管理用户

删除用户

需要功能

1. 获取待删除用户名
2. kill正在运行属于该用户的进程
3. 找出属于该用户所有的文件
4. 删除该用户

脚本步骤

给用户60秒来输入想要删除的用户

echo "Please enter the username of the user "
echo -e "account you wish to delete from system: \c"
#account账户
read -t 60 ANSWER

-z判断ANSWER变量是否为空

while [ -z "$ANSWER" ]
do
[...]
echo "Please enter the username of the user "
echo -e "account you wish to delete from system: \c"
read -t 60 ANSER
done

通过给ASK_COUNT变量增值，设定不同的消息回应脚本用户

case $ASK_CONT in
2)
    echo
    echo "Please answer the question."
    echo
;;
3)
    echo
    echo "One last try...please answer the question."#最后一次试着
    echo 
;;
4)
    echo
    echo "Since you refuse to anser the question..."#由于你拒绝回答问题
    echo "exiting program."#退出程序
    echo
    exit
;;
esac

完整脚本如下

get_answer函数

这个函数的意义在于，判断用户输入的值是否为空，为空则对ASK_COUNT变量累加，第一次输入为空则输出2，第二次输出3，第三次输出4退出脚本

function get_answer {
unset ANSWER
ASK_COUNT=0
while [ -z "$ANSWER" ]
DO
        ((ASK_COUNT++))
        case $ASK_COUNT in
        2)
         echo
         echo "Please answer the question."
while [ -z "$ANSWER" ]
do
        ((ASK_COUNT++))
        case $ASK_COUNT in
        2)
         echo
         echo "Please answer the question."
         echo
        ;;
        3)
         echo
         echo "One last try...please answer the question."
         echo
        ;;
        4)
         echo 
         echo "Since you refuse to answer the question..."
         echo "exiting program."
         echo
         exit
        ;;
        esac
        echo
        if [ -n "$LINE2" ]
        then
                echo $LINE1
                echo -e $LINE2" \c"
        else
                echo -e $LINE1" \c"
        fi
done
unset LINE1
unset LINE2
}

process_answer函数

判断用户输入是否为y等，如果不是退出脚本

function process_answer {
case $ANSWER in
y|Y|YES|yes|Yes|yEs|yeS|YEs|yES )
#if useranswers "yes",do nothing
*)
        echo
        echo $EXIT_LINE1
        echo $EXIT_LINE2
        echo
        exit
;;
esac
unset EXIT_LINE1
unset EXIT_LINE2
}

脚本主体

#Main Script
echo "Step #1 - Determine User Account name to Delete "
echo
LINE1="Please enterthe username of the user "
LINE2="account you wish to delete from system:"
get_answer #判断用户输入是否为空
USER_ACCOUNT=$ANSWER
LINE1="Is $USER_ACCOUNT the user account "
LINE2="you wish to delete from the system? [y/n]"
get_answer #判断用户输入是否为空
EXIT_LINE1="Because the account, $USER_ACCOUNT, is not"
EXIT_LINE2="the one you wish to delete, we are leaving the script..."
process_answer #判断用户是否输入为y
#Check that USER_ACCOUNT is really an account确定 on the system
USER_ACCOUNT_RECORD=$(cat /etc/passwd | grep -w $USER_ACCOUNT) #从/etc/passwd文件中判断用户是否存在
if [ $? -eq 1 ]
then
    echo 
    echo "Account, $USER_ACCOUNT, not found."
    echo "Leaving the script..."
    echo
    exit
fi
echo
echo "I found this record:"
echo $USER_ACCOUNT_RECORD
LINE1="Is this the correct User Account? [y/n]"
get_answer
EXIT_LINE1="Because the account,$USER_ACCOUNT, is not "
EXIT_LINE2="the one you wish to delete, we are leaving the script..."
process_answer
echo
echo "Step #2 - Find process on system belonging to user account"
echo
ps -u $USER_ACCOUNT > /dev/null #查找用户进程，如果有则询问是否kill
case $? in
1)
    echo "There are no processes for this account currently running."
    echo
;;
0)
    echo "$USER_ACCOUNT has the following processes running: "
    echo
    ps -u $USER_ACCOUNT
LINE1="Would you like me to kill the process(es)?[y/n]"
get_anser
case $ANSWER in
y|Y|YES|yes|Yes|yEs|yeS|YEs|yES )
    echo
    echo "Killing off process(es)..."
COMMAND_1="ps -u $USER_ACCOUNT --no-heading"
COMMAND_3="xargs -d \\n /usr/bin/sudo /bin/kill -9"
$COMMAND_1 | gawk '{print $1}' | $COMMAND_3
echo
echo "Process(es) killed."
;;
*)
    echo
    echo "Will not kill the process(es)"
    ;;
    esac
;;
esac


#Create a report of all files owned by User Account
echo 
echo "Step #3 - Find files on system belonging to user account"
echo
echo "Creating a report of all files owned by $USER_ACCOUNT."
echo
echo "It is recommended that you backup/archive these files,"
echo "and then do one of two things:"
echo "    1)Delete the files"
echo "    2)Change the files' ownership to a current user account."
echo
echo "Please wait. This may take a while..."
REPORT_DATE=$(date +%y%m%d)
REPORT_FILE=$USER_ACCOUNT"_Files_"$REPORT_DATE".rpt" #查找所有关于要删除用户的文件位置信息并生成以日期命名后缀rpt格式的文件可用cat查看，文件在在运行脚本的当前目录下。
find / -user $USER_ACCOUNT > $REPORT_FILE 2>/dev/null
echo
echo "Report is complete."
echo "Name of report:    $REPORT_FILE"
echo "Location of report:    $(pwd)"
echo
#Remove User Account
echo
echo "Step #4 - Remove user account"
echo
LINE1="Remove $USER_ACCOUNT's account from system?[y/n]"
get_answer
EXIT_LINE1="Since you do not wish to remove the user account."
EXIT_LINE2="$USER_ACCOUNT at this time, exiting the script..."
process_answer
userdel $USER_ACCOUNT #如果家目录下的文件不需要加上-r
echo
echo "User account, $USER_ACCOUNT, has been removed"
echo
exit

这脚本真特么长

老外没有删除该用户家目录下的文件，实际环境中可能文件留着有用

老外的逻辑真是666

别看这么长，我当时也被吓住了，不过翻来覆去单词就那么几个，脚本还是挺简单的，再说反正搞计算机的英语迟早要会

 学习来自：《Linux命令行与Shell脚本大全 第3版》第24章