模块三、企业实战案例

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	$pass" >>/tmp/user.txt &&
          action "oldboy$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 est1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 "$n	 `$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 "$n	 `$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 " ," "
" <12.log | sort|uniq -c| sort -rn

方法2：

[root@centos6-kvm3 scripts]# tr " ," "
" <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