1.ssh连接三次以上失败则加入到黑名单中

    #!/bin/bash
    cat /var/log/secure | awk '/Failed/{print $(NF-3)}' | sort | uniq -c |awk '{print $2"="$1}' > /tmp/blacklist
     
    MAXCOUNT="3"
     
    for i in `cat /tmp/blacklist`
    do
        IP=`echo $i | awk -F= '{print $1}'`
        NUM=`echo $i | awk -F= '{print $2}'`
     
    if [ $NUM -gt $MAXCOUNT ];then
     
       grep $IP /etc/hosts.deny > /dev/null
       if [ $? -gt 0 ];then
    	echo "sshd:$IP" >> /etc/hosts.deny
       fi
    fi 
    done

2。创建数据库tom，harry，natasha，并在其中建立表，并备份三个数据库

#!/bin/bash
MYUSER=root
MYPASS=westos
MYCMD="mysql -u$MYUSER -p$MYPASS"
MYDUMP="mysqldump -u$MYUSER -p$MYPASS"
DBPATH=/home/backup
 
for dbname in tom harry natasha
do
	$MYCMD -e "create database $dbname"
done
 
[ ! -d "$DBPATH" ] && mkdir -p $DBPATH
for dbname in `mysql -uroot -pwestos -e "show databases;" | sed '1,2d' |egrep -v "mysql|schema"`
do
	$MYDUMP $DBNAME | gzip > $DBPATH/${dbname}_$(date +%F).sql.gz
done
 
for dbname in tom harry natasha
do
    echo ========${dbname}.test========
    $MYCMD -e "use $dbname;select * from ${dbname}.test;"
done

（3）数据库备份，执行script.sh $dbpasswd 备份数据库中所有库到/mnt/mysqldump目录中，备份文件名称为“库名称.sql”，当此文件存在时进入交互模式，询问动作，输入“s”跳过备份，输入“b”，备份“库名称.sql”为“库名称_backup.sql”,输入“O”时，覆盖原文件,e表示退出
 

#!/bin/bash
mkdir -p /mnt/mysqldump
DATABASE=`mysql -uroot -pwestos -e "show databases;" | sed '1,2d' | egrep -v "mysql|schema"`
 
for MYSQL_NAME in $DATABASE
do
     if [ -e /mnt/mysqldump/${MYSQL_NAME}.sql ];then
	read -p "${MYSQL_NAME} has been dumped!
	[S]kip [B]ackup [O]verwrite [E]xit
	please input the action:" ACTION   
	
	case $ACTION in 
	s|S)
	;;
	b|B)
	mysqldump -uroot -p$1 $MYSQL_NAME > /mnt/mysqldump/${MYSQL_NAME}_backup.sql
	;;
	o|O)
	mysqldump -uroot -p$1 $MYSQL_NAME > /mnt/mysqldump/${MYSQL_NAME}.sql
	;;
	e|E)
	echo -e "Bye"
	exit 0
	esac
  else
	mysqldump -uroot -p$1 $MYSQL_NAME > /mnt/mysqldump/${MYSQL_NAME}.sql
	echo -e "$MYSQL_NAME is backuped!"
	fi
done