十四、企业实战案例
（一）使用for循环在/oldboy目录下批量创建10个html文件，其中文件名包含10个随机小写字母加固定字符串0ldoby。
思路分析，产生随机数字方法：
①核心是创建10个随机小写字母。
echo $RANDOM 范围是0-32767
openssl rand -base64 100
date +%s%N
head /dev/urandom/cksum
uuidgen
cat /proc/sys/kernel/random/uuid
mkpasswd (yum install expect -y)
-l:长度
-d:数字
-c:小写字母
-C:大写字母
-s：特殊字符
[root@centos6-kvm3 shili]# cat 14-01.sh
#!/bin/bash
path="oldboy"
[ -d /path ] || mkdir -p oldboy/
for n in {1..10}
do
random=`echo "OLDBOY$RANDOM" | md5sum | tr '0-9' 'm-z' | cut -c 2-11`
touch $path/${random}_oldboy.html
done
[root@centos6-kvm3 shili]#
（二） 、批量改名特殊案例。将以上面试题1中结果 文件名中的oldboy字符串全部改成oldgirl（最好用for循环实现），并且将扩展名html全部改成大写。
[root@centos6-kvm3 shili]# cat 14-02.sh
#!/bin/bash
for file in `ls oldboy/*.html`
do
mv $file ${file/oldboy.html/oldgirl.HTML}
done
[root@centos6-kvm3 shili]#
方法2
[root@centos6-kvm3 oldboy]# ls | awk -F "oldgirl.HTML" '{print "mv",$0, $1 "oldboy.html"}' | bash
方法3
[root@centos6-kvm3 oldboy]# rename "oldboy.html" "oldgirl.HTML" *.html
（三）、企业shell面试题3：批量创建特殊要求用户案例。
批量创建10个系统账号oldboy01-oldboy10并设置密码（密码为随机数，要求数字和字母混合）。
方法1
[root@centos6-kvm3 shili]# cat 14-03.sh
#!/bin/bash
. /etc/init.d/functions
if [ $UID -ne 0 ]
then
echo "please use root."
exit 1
fi
for n in {41..50}
do
pass=`openssl rand -base64 10`
if [ `grep -w "oldboy$n" /etc/passwd|wc -l` -eq 0 ]
then
useradd oldboy$n &>/dev/null &&\
echo $pass | passwd --stdin oldboy$n &&\
echo -e "oldboy$n\t$pass" >>/tmp/user.txt &&\
action "oldboy$n is successful." /bin/true
else
action "oldboy$n is exist." /bin/false
fi
done
[root@centos6-kvm3 shili]#
方法2
[root@centos6-kvm3 shili]# cat 14-03-01.sh #!/bin/bash for n in `seq -w 11 20` do pass=`openssl rand -base64 10` useradd oldboy$n echo "oldboy$n:$pass" >>/tmp/chpasswd.log done chpasswd </tmp/chpasswd.log [root@centos6-kvm3 shili]#
（四）扫描网络内存活主机案例。写一个shell脚本，判断10.0.0.0/24当前网络中主机数量。当前哪些在线的有哪些。
如何判断主机存活。
①ping
-c次数
-i 间隔
②nmap (yum)
nmap -sP 10.0.0.0/24
方法1
[root@centos6-kvm3 shili]# cat 14-04.sh
#!/bin/bash
for n in {1..254}
do
{
if `ping -c 1 -w 3 10.0.0.$n &>/dev/null`
then
echo "10.0.0.$n is up."
else
echo "10.0.0.$n is down."
fi
} &
done
方法2
[root@centos6-kvm3 shili]# nmap -sP 10.0.0.0/24 | awk '/Nmap scan report for/{print $NF}'
（五）、mysql数据库分库备份
mysql -uroot -poldboy123 -e "show databases" | grep -v _scheme|sed -1d
分库备份：
mysqldump -B oldboy | gzip > bak.sql.gz
[root@centos6-kvm3 scripts]# vim mysql.sh
#!/bin/bash
path=/back
[ -d $path ] || mkdir $path -p
for dbname in `mysql -uroot -poldboy123 -e "show databases;" 2>/dev/null | grep -v _schema | sed -1d`
do
mysqldump -uroot -poldboy123 -B $dbname | gzip >$path/${dbname}.sql.gz
done
（六）、mysql分库分表备份案例分析及开发实现
如何实现mysql数据库进行分库加分表备份，请用脚本实现。
解答：
mysqldump oldboy test test1| gzip >bak.sql.gz
1,oldboy 库名
2，test\test1都是表名
方法：
mysqldump -B oldboy |gzip >bak.sql.gz
mysqldump oldboy test1
mysqldump -B oldgril | gzip >bak.sql.gz
mysqldump oldgril test1
mysql -uroot -poldboy123 -e "show tables from wordpress;" 2>/dev/null | sed -1d
[root@centos6-kvm3 scripts]# cat mysql.sh
#!/bin/bash
path=/back
[ -d $path ] || mkdir $path -p
for dbname in `mysql -uroot -poldboy123 -e "show databases;" 2>/dev/null | grep -v _schema | sed 1d`
do
for tname in `mysql -uroot -poldboy123 -e "show tables from $dbname;" 2>/dev/null | grep 1d `
do
if [ "$dbname" = "mysql" ]
then
mysqldump -uroot -poldboy123 $dbname $tname | gzip >$path/${dbname}_${tname}.sql.gz
else
mysqldump $dbname $tname | gzip >$path/${dbname}_${tname}.sql.gz
fi
done
done
[root@centos6-kvm3 scripts]#
七、SSH免秘钥批量分发文件专业脚本
有3台机器，m01，backup，nfs01,采用ssh免秘钥实现从m01到其他两台机器无密码登录后，请写脚本实现从m01批量分发任意文件到其他两台机器的任意目录下。
免密环境生成：
[root@centos6-kvm3 scripts]# ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
12:af:26:77:1e:2d:2b:ce:94:aa:f9:be:c5:a3:c8:90 root@centos6-kvm3
The key's randomart image is:
+--[ RSA 2048]----+
| |
| |
| . |
| o |
| . S |
| . . + . |
|E . X + . |
| o o X.+ + |
| =+*oo.o |
+-----------------+
[root@centos6-kvm3 scripts]# ll ~/.ssh/
total 8
-rw------- 1 root root 1675 Jan 27 21:48 id_rsa
-rw-r--r-- 1 root root 399 Jan 27 21:48 id_rsa.pub
[root@centos6-kvm3 scripts]# cd ~/.ssh/
[root@centos6-kvm3 .ssh]# ssh-copy-id id_rsa.pub 10.0.0.8
[root@centos6-kvm3 scripts]# cat fenfa.sh
#!/bin/bash
. /etc/init.d/functions
if [ $# -ne 2 ]
then
echo "usage:$0 localdir remotedir"
exit 1
fi
for n in 8 41 43
do
scp -rp $1 10.0.0.$n:$2 &>/dev/null
if [ $? -eq 0 ]
then
action "10.0.0.$n is successful" /bin/true
else
action "10.0.0.$n is failure" /bin/false
fi
done
[root@centos6-kvm3 scripts]#
八、破解RANDOM随机数案例
已知下面的字符串是通过RANDOM随机数变量md5sum后，再截取一部分字符串的结果，请破解这些字符串对应的使用的md5sum处理前的RANDOM对应的数字。
21029299
00205d1c
a3da1677
1f6d12dd
890684b
解答：
[root@centos6-kvm3 .ssh]# cat random.sh
#!/bin/bash
array=(
21029299
00205d1c
a3da1677
1f6d12dd
890684b
)
funmd5(){
for n in {1..32767}
do
echo "$n\t `$n|md5sum`" >>/tmp/md5sum.log
done
}
funjudge(){
for n in ${array[*]}
do
if [ `echo grep $n /tmp/md5sum.log|wc -l` -eq 1 ]
then
echo `grep $n /tmp/md5sum.log`
fi
done
}
main(){
funmd5
funjudge
}
main
[root@centos6-kvm3 .ssh]#
优化方法1：
[root@centos6-kvm3 .ssh]# cat random1.sh
#!/bin/bash
array=(
21029299
00205d1c
a3da1677
1f6d12dd
890684b
)
funmd5(){
for n in {1..32767}
do
echo "$n\t `$n|md5sum`" >>/tmp/md5sum1.log
done
}
funjudge(){
char="`echo ${array[*]} | tr " " "|"`"
egrep $char /tmp/md5sum1.log
}
main(){
funmd5
funjudge
}
main
[root@centos6-kvm3 .ssh]#
九、批量检查多个网站地址是否正常
企业面试题:批量检查多个网站地址是否正常。
要求：
1、使用shell数组方法实现，检查策略尽量模拟用户访问。
2、每10s做一次所有的检测，无法访问的输出报警。
3、待检测的地址如下：
http://blog.oldboyedu.com
http://blog.ettiantian.org
http://www.luffycity.com
http://10.0.0.7
解答：
wget --spider #模拟爬虫，不下载html文件。
方法1
[root@centos6-kvm3 .ssh]# cat url.sh
#!/bin/bash
. /etc/init.d/functions
array=(
http://blog.oldboyedu.com
http://www.baidu.com
http://blog.ettiantian.org
http://www.luffycity.com
http://10.0.0.7
)
checkurl(){
wget -t 2 -T 5 -o /dev/null -q $1
if [ $? -eq 0 ]
then
action "$1 is successfull." /bin/true
else
action "$1 is failure." /bin/false
fi
}
dealurl(){
for n in ${array[*]}
do
checkurl $n
done
}
main(){
while true
do
dealurl
sleep 2
echo "--------"
done
}
main
[root@centos6-kvm3 .ssh]#
方法2
[root@centos6-kvm3 .ssh]# cat url1.sh
#!/bin/bash
. /etc/init.d/functions
array=(
http://blog.oldboyedu.com
http://www.baidu.com
http://blog.ettiantian.org
http://www.luffycity.com
http://10.0.0.7
)
checkurl(){
wget -t 2 -T 5 -o /dev/null -q $1
if [ $? -eq 0 ]
then
action "$1 is successfull." /bin/true
else
action "$1 is failure." /bin/false
fi
}
dealurl(){
for ((i=0;i<${#array[*]};i++))
do
checkurl ${array[$i]}
done
}
main(){
while true
do
dealurl
sleep 2
echo "--------"
done
}
main
[root@centos6-kvm3 .ssh]#
方法3
[root@centos6-kvm3 .ssh]# cat url2.sh
#!/bin/bash
. /etc/init.d/functions
checkurl(){
wget -t 2 -T 5 -o /dev/null -q $1
if [ $? -eq 0 ]
then
action "$1 is successfull." /bin/true
else
action "$1 is failure." /bin/false
fi
}
dealurl(){
while read line
do
checkurl $line
done < ./url.log
}
main(){
while true
do
dealurl
sleep 2
echo "--------"
done
}
main
[root@centos6-kvm3 .ssh]#
十、解决dos攻击生成案例
写一个shell脚本解决dos攻击生成案例。
请根据web日志或者网络连接数，监控某个ip并发连接数或者短时间内pv达到100（读者根据实际请设定），即调用防火墙命令封掉对应的ip。防火墙命令为：iptables -I INPUT -s IP 地址 -j DROP
解答：
DOS deny of service
DDOS
分析：
1、封ip的命令
iptables -I INPUT -s IP 地址 -j DROP
2、web日志或者网络连接数
日志文件，netstat -an| grep -i est 排序去重。
3、判断pv或者连接数大于100，取出ip后封。
取攻击ip的方法：
方法1
[root@centos6-kvm3 scripts]# awk '{s[$1]++}END{for(key in s) print s[key],key}' access_2010-12-8.log | uniq |sort -nr
35 59.33.26.105
23 123.122.65.226
8 124.115.4.18
方法2
[root@centos6-kvm3 scripts]# awk '{print $1}' access_2010-12-8.log | uniq -c | sort -nr
35 59.33.26.105
23 123.122.65.226
8 124.115.4.18
[root@centos6-kvm3 scripts]#
[root@centos6-kvm3 scripts]# cat dos.sh
#!/bin/bash
awk '{s[$1]++}END{for(key in s) print s[key],key}' access_2010-12-8.log |sort -nr | head >/tmp/ip.log
while read line
do
ip=`echo $line|awk '{print $2}'`
count=`echo $line|awk '{print $1}'`
if [ $count -gt 30 -a `grep "$ip" /tmp/drop.log|wc -l` -lt 1 ]
then
iptables -I INPUT -s `echo $line|awk '{print $2}'` -j DROP &&\
echo "echo $line|awk '{print $2}'" >>/tmp/drop.log
else
echo "echo $line|awk '{print $2}'" >>/tmp/accept.log
fi
done </tmp/ip.log
[root@centos6-kvm3 scripts]#
[root@centos6-kvm3 scripts]# iptables -nL
获取网络连接数的方法：
[root@centos6-kvm3 scripts]# awk -F "[ :]+" '/ESTAB/{S[$(NF-3)]++}END{for(k in S) print S[k],k}' netstat.log| sort -rn | head
[root@centos6-kvm3 scripts]# awk '/ESTAB/{print $(NF-1)}' netstat.log | awk -F ":" '{print $1}'| uniq -c | sort -rn |head
[root@centos6-kvm3 scripts]# vim dos1.sh
#!/bin/bash
awk -F "[ :]+" '/ESTAB/{S[$(NF-3)]++}END{for(k in S) print S[k],k}' netstat.log| sort -rn | head >/tmp/ip.log
while read line
do
ip=`echo $line|awk '{print $2}'`
count=`echo $line|awk '{print $1}'`
if [ $count -gt 30 -a `grep "$ip" /tmp/drop.log|wc -l` -lt 1 ]
then
iptables -I INPUT -s `echo $line|awk '{print $2}'` -j DROP &&\
echo "echo $line|awk '{print $2}'" >>/tmp/drop.log
else
echo "echo $line|awk '{print $2}'" >>/tmp/accept.log
fi
done </tmp/ip.log
~ [root@centos6-kvm3 scripts]# iptables -nL
十一、开发mysql服务启动停止脚本
要求：用函数，case语句，if语句等实现。
解答：
/etc/init.d/mysqld {start | stop | restart}
分析：
1、启动
mysql_safe --user=mysql & 一定要在命令行测试成功。
2、停止
mysqladmin -uroot -ppasswd shutdown
killall,pkill
kill pid 推荐
[root@centos6-kvm3 scripts]# cat mysqld.sh
# chkconfig: 2345 20 80
# description: mysql start stop
#!/bin/bash
lockfile=/var/lock/subsys/mysqld
. /etc/init.d/functions
mysqld_pid_file_path="/application/mysql/data/web01.pid"
mysqld_safe=/application/mysql/bin/mysqld_safe
start(){
/bin/sh $mysqld_safe --datadir=/application/mysql/data --pid-file=$mysqld_pid_file_path &>/dev/null &
retval=$?
if [ $retval -eq 0 ]
then
action "mysql start ok" /bin/true
touch $lockfile
return $retval
else
action "mysql start fail" /bin/false
return $retval
fi
}
stop(){
if test -s "$mysqld_pid_file_path"
then
mysqld_pid=`cat $mysqld_pid_file_path`
if (kill -0 $mysql_pid &>/dev/null)
then
kill $mysqld_pid
retval=$?
if [ $retval -eq 0 ]
then
action "mysql stop ok" /bin/true
rm $lockfile
return $retval
else
action "mysql stop fail" /bin/false
return $retval
fi
else
echo "mysqld process is not exits."
return 2
fi
else
echo "$mysqld_pid_file_path is not exist,or mysqld does not startup."
fi
}
case $1 in
start)
start
retval=$?
;;
stop)
stop
retval=$?
;;
restart)
stop
sleep 2
start
retval=$?
;;
*)
echo "usage:$0 {start|stop|restart}"
exit 1
esac
exit $retval
[root@centos6-kvm3 scripts]#
十二、单词及字母去重排序案例
用shell脚本处理以下内容
1、按单词出现频率降序排序。
2、按字母出现频率降序排序。
the squid project provides a number of resources to assist users design,implement and support squid installations. Please browse the documentation and support sections for more infomation,by oldboy training.
1、按单词出现频率降序排序。
方法1:
[root@centos6-kvm3 scripts]# tr " ," "\n" <12.log | sort|uniq -c| sort -rn
方法2：
[root@centos6-kvm3 scripts]# tr " ," "\n" <12.log | awk '{S[$1]++}END{for(k in S) print S[k],k}'| sort -nr
方法3
[root@centos6-kvm3 scripts]# xargs -n1 <12.log | sort|uniq -c|sort -nr
2、按字母出现的频率进行降序排序。
方法1
[root@centos6-kvm3 scripts]# grep -o "[^ ]" 12.log | sort|uniq -c|sort -nr
方法2
[root@centos6-kvm3 scripts]# grep -o "[^ ]" 12.log | awk '{S[$1]++}END{for(k in S) print S[k],k}'|sort -rn
方法3
[root@centos6-kvm3 scripts]# sed 's#[ ,\.]##g' 12.log | awk -F "" '{for(i=1;i<NF;i++)s[$i]++}END{for(k in s) print s[k],k}'| sort -nr
十三、按单词去重排序案例高级方法
竖着处理：
[root@centos6-kvm3 scripts]# awk -F '[ ,.]+' '{for(i=1;i<NF;i++)s[$i]++}END{for(k in s) print s[k],k}' 12.log | sort -nr
来源：https://www.cnblogs.com/cuiyongchao007/p/12239428.html