shell编程19例 / 憋错料

本文所有题目来自于老男孩51cto博客，地址如下：

http://oldboy.blog.51cto.com/2561410/1632876

转载请注明最原始出处。

本文中所有题目答案都是按我自己的思路整理的，并不代表最完美答案，适合新手学习参考。

<a href="#_Toc420786634">1 监控mysql主从同步</a>

<a href="#_Toc420786635">2 批量创建文件</a>

<a href="#_Toc420786637">4 批量创建账户</a>

<a href="#_Toc420786638">5 判断当前局域网存在的主机</a>

<a href="#_Toc420786639">6 写一个脚本解决DOS攻击生产案例</a>

<a href="#_Toc420786640">7 开发mysql多实例启动脚本</a>

<a href="#_Toc420786641">8 对MySQL数据库进行分库备份</a>

<a href="#_Toc420786642">9 对MySQL数据库进行分库加分表备份</a>

<a href="#_Toc420786643">10 字符串打印</a>

<a href="#_Toc420786646">13 检测web服务及mysql服务</a>

<a href="#_Toc420786647">14 监控memcached</a>

<a href="#_Toc420786648">15 监控web站点目录是否被篡改</a>

<a href="#_Toc420786649">16 rsync服务启动脚本</a>

<a href="#_Toc420786651">18 暴力破解密码</a>

<a href="#_Toc420786652">19 批量检查多个网站地址是否正常</a>

<h1><a name="_Toc420786634"></a>1 监控mysql主从同步</h1>

（生产实战案例）：监控MySQL主从同步是否异常，如果异常，则发送短信或者邮件给管理员。提示：如果没主从同步环境,可以用下面文本放到文件里读取来模拟：

阶段1：开发一个守护进程脚本每30秒实现检测一次。

阶段2：如果同步出现如下错误号（1158,1159,1008,1007,1062），则跳过错误。

阶段3：请使用数组技术实现上述脚本（获取主从判断及错误号部分）

<pre class="brush:shell">#!/bin/bash

#lixinyu linux

#2015-5-15

#监控mysql主从同步

USER=root

PASSWORD=123456

PORT=3307

error=(1158 1159 1008 1007 1062)

MYSQLCMD="mysql -u$USER -p$PASSWORD -S /data/$PORT/mysql.sock"

is_run(){

[ `lsof -i:$PORT|wc -l` -lt 2 ]&&{

echo "mysql server is stoping"

exit 1

}

status_array(){

status=($($MYSQLCMD -e "show slave status\G"|egrep "_Running|Last_Errno|Behind_Master"|awk ‘{print $NF}‘))

}

status_error(){

flag=0

for((i=0;i<${#error[*]};i++))

if [ "$1" == "${error[$i]}" ]

then

$MYSQLCMD -e "stop slave;set global sql_slave_skip_counter=1;start slave;"

else

let flag=flag+1

done

[ $flag -ne 0 ]&&echo "MySQL slave is failed, errorno is $1"

}

judge_slave(){

status_array

if [ "${status[0]}" == "Yes" -a "${status[1]}" == "Yes" -a "${status[3]}" = "0" ]

then

echo "MySQL slave is ok"

else

status_error ${status[2]}

}

main(){

while true

is_run

judge_slave

sleep 5

done

}

main

</pre>

<h1><a name="_Toc420786635"></a>2 批量创建文件</h1>

使用for循环在/oldboy目录下通过随机小写10个字母加固定字符串oldboy批量创建10个html文件，名称例如为：

jdxexendbe_oldboy.html ugaywanjlm_oldboy.html xzzruhdzda_oldboy.html

qcawgsrtkp_oldboy.html vfrphtqjpc_oldboy.html

解答脚本

<pre class="brush:shell">#!/bin/bash

if [ ! -d /oldboy ]

then

mkdir /oldboy -p

for ((i=1;i<=10;i++))

touch /oldboy/`echo $RANDOM|md5sum|cut -c 1-10`_oldboy.html

done

</pre>

将以上文件名中的oldboy全部改成oldgirl(用for循环实现),并且html改成大写。请用两种以上方法实现

方法一

<pre class="brush:shell">#!/bin/bash

cd /oldboy

name=($(ls /oldboy))

for ((i=0;i<${#name[*]};i++))

/bin/mv ${name[i]} `ls ${name[i]}|sed -rn ‘s#(^.*)_oldboy.html#\1_oldgirl.HTML#gp‘`

done

</pre>

改回来（也可以作为一种方法）

rename "oldgirl.HTML" "oldboy.html" *.HTML

方法二

<pre class="brush:shell">#!/bin/bash

cd /oldboy

for f in `ls /oldboy`

/bin/mv $f `echo $f|sed -rn ‘s#(^.*)oldboy.html#\1oldgirl.HTML#gp‘ `

done

</pre>

<h1><a name="_Toc420786637"></a>4 批量创建账户</h1>

批量创建10个系统帐号oldboy01-oldboy10并设置密码（密码为随机8位字符串）。

<pre class="brush:shell">#!/bin/bash

random(){

password=`echo $RANDOM|md5sum|cut -c 1-8`

}

for user in `seq -w 10`

useradd oldboy$user

random

echo $password|passwd --stdin oldboy$user

echo oldboy$user $password >>/opt/user.txt

done

</pre>

<h1><a name="_Toc420786638"></a>5 判断当前局域网存在的主机</h1>

写一个脚本，实现判断10.0.0.0/24网络里，当前在线用户的IP有哪些（方法有很多）

<pre class="brush:shell">#!/bin/bash

. /etc/init.d/functions

for ((i=1;i<=254;i++))

ping -c1 10.0.0.$i >/dev/null 2>&1

if [ $? -eq 0 ]

then

action "10.0.0.$i is ok" /bin/true

else

action "10.0.0.$i is ok" /bin/false

done

</pre>

<h1><a name="_Toc420786639"></a>6 写一个脚本解决DOS攻击生产案例</h1>

提示：根据web日志或者或者网络连接数，监控当某个IP并发连接数或者短时内PV达到100，即调用防火墙命令封掉对应的IP，监控频率每隔3分钟。防火墙命令为：iptables-A INPUT -s 10.0.1.10 -j DROP。

方法一（注意在函数中，iptables命令要使用全路径）

<pre class="brush:shell">#!/bin/bash

count=(`egrep "EST" netstat.log |awk -F "[ :]+" ‘{print $6}‘|sort -n|uniq -c|awk ‘{print $1}‘`)

ip=(`egrep "EST" netstat.log |awk -F "[ :]+" ‘{print $6}‘|sort -n|uniq -c|awk ‘{print $2}‘`)

iptables(){

for ((i=0;i<${#count[*]};i++))

if [ ${count[$i]} -gt 10 ] && [ `/sbin/iptables -L -n|grep "${ip[$i]}"|wc -l` -lt 1 ]

then

echo `date` >>/opt/DOS.log

echo ${count[$i]} ${ip[$i]} >> /opt/DOS.log

/sbin/iptables -A INPUT -s ${ip[$i]} -j DROP

done

}

main(){

while true

iptables

sleep 180

done

}

main

</pre>

方法二：

<pre class="brush:shell">while true

#awk ‘{print $1}‘ access.log|grep -v "^$"|sort|uniq -c >/tmp/tmp.log

grep EST a.log|awk -F ‘[ :]+‘ ‘{print $6}‘|sort|uniq -c >/tmp/tmp.log

#netstat -an|grep EST|awk -F ‘[ :]+‘ ‘{print $6}‘|sort|uniq -c >/tmp/tmp.log

exec </tmp/tmp.log

while read line

ip=`echo $line|awk ‘{print $2}‘`

count=`echo $line|awk ‘{print $1}‘`

if [ $count -gt 3 ] && [ `iptables -L -n|grep "$ip"|wc -l` -lt 1 ]

then

iptables -I INPUT -s $ip -j DROP

echo "$line is dropped" >>/tmp/droplist.log

done

sleep 5

done

</pre>

加入定时任务

*/3 * * * * /bin/sh /server/scripts/ip_drop.sh >/dev/null 2>&1

<h1><a name="_Toc420786640"></a>7 开发mysql多实例启动脚本</h1>

已知mysql多实例启动命令为：mysqld_safe--defaults-file=/data/3306/my.cnf &

停止命令为：mysqladmin -u root -poldboy123 -S /data/3306/mysql.sockshutdown

请完成mysql多实例启动启动脚本的编写

要求：用函数，case语句、if语句等实现。

<pre class="brush:shell">#!/bin/bash

#lixinyu linux

#2015-5-15

# chkconfig: 2345 25 60

# description: mysql start and stop scripts

. /etc/init.d/functions

DIR=/data/3306

USER=root

PASSWORD=123456

PORT=3306

function mysql_start(){

PID=`lsof -i:$PORT|wc -l`

[ $PID -lt 2 ]&&{

/usr/local/sbin/mysqld_safe --defaults-file=$DIR/my.cnf >/dev/null 2>&1 &

if [ $? -eq 0 ]

then

sleep 3

action "mysqld is start" /bin/true

else

action "mysqld is start" /bin/false

return 0

}||{

action "The mysql is running now" /bin/false

return 1

}

function mysql_stop(){

PID=`lsof -i:$PORT|wc -l`

[ $PID -ge 2 ]&&{

/usr/local/sbin/mysqladmin -u $USER -p"$PASSWORD" -S $DIR/mysql.sock shutdown >/dev/null 2>&1 &

if [ $? -eq 0 ]

then

sleep 3

action "mysqld is stop" /bin/true

else

action "mysqld is stop" /bin/false

return 0

}||{

action "The mysql is stoping now" /bin/false

return 1

}

function USAGE(){

echo "USAGE:$0 {start|stop|restart}"

}

[ $# -ne 1 ]&&{

USAGE

exit 1

}

case "$1" in

start)

mysql_start

;;

stop)

mysql_stop

;;

restart)

mysql_stop

mysql_start

;;

USAGE

esac

</pre>

<h1><a name="_Toc420786641"></a>8 对MySQL数据库进行分库备份</h1>

<pre class="brush:shell">#!/bin/bash

#lixinyu linux

#2015-5-20

user=root

password=123456

sock=/data/3306/mysql.sock

MYCMD="mysql -u$user -p$password -S $sock"

MYDUMP="mysqldump -u$user -p$password -S $sock"

for database in `$MYCMD -e "show databases;"|sed ‘1d‘|egrep -v ‘mysql|_schema‘`

$MYDUMP -B --master-data=2 --events --single-transaction $database|gzip >/opt/${database}_$(date +%F).sql.gz

done

</pre>

<h1><a name="_Toc420786642"></a>9 对MySQL数据库进行分库加分表备份</h1>

<pre class="brush:shell">#!/bin/bash

#lixinyu linux

#2015-5-20

user=root

password=123456

sock=/data/3306/mysql.sock

MYCMD="mysql -u$user -p$password -S $sock"

MYDUMP="mysqldump -u$user -p$password -S $sock"

for database in `$MYCMD -e "show databases;"|sed ‘1d‘|egrep -v "mysql|_schema"`

mkdir /backup/${database} -p

for table in `$MYCMD -e "show tables from $database"|sed "1d"`

$MYDUMP $database $table|gzip >/backup/${database}/${database}.${table}_$(date +%F).sql.gz

done

</pre>

<h1><a name="_Toc420786643"></a>10 字符串打印</h1>

<strong>请用至少两种方法实现！</strong>

bash for循环打印下面这句话中字母数不大于6的单词(昆仑万维面试题)。

I am oldboy teacher welcome to oldboy training class.

方法一

<pre class="brush:shell">#!/bin/bash

for n in I am oldboy teacher welcome to oldboy training class

if [ ${#n} -le 6 ];then

echo $n

done

</pre>

方法二

<pre class="brush:shell">#!/bin/bash

chars=(I am oldboy teacher welcome to oldboy training class)

for ((i=0;i<${#chars[*]};i++))

if [ ${#chars[i]} -le 6 ];then

echo ${chars[i]}

done

</pre>

开发shell脚本分别实现以脚本传参以及read读入的方式比较2个整数大小。以屏幕输出的方式提醒用户比较结果。注意：一共是开发2个脚本。当用脚本传参以及read读入的方式需要对变量是否为数字、并且传参个数做判断。

<pre class="brush:shell">#!/bin/bash

read -t 30 -p "pls input two num:" a b

[ ${#a} -eq 0 -o ${#b} -eq 0 ]&&{

echo "you need input two num"

exit 1

}

expr $a + 1 &>/dev/null

RETVAL_A=$?

expr $b + 1 &>/dev/null

RETVAL_B=$?

[ $RETVAL_A -ne 0 -o $RETVAL_B -ne 0 ]&&{

echo "one of your input is not int."

exit 1

}

[ $a -gt $b ]&&{

echo "$a>$b"

exit 0

}

[ $a -eq $b ]&&{

echo "$a=$b"

exit 0

}

[ $a -lt $b ]&&{

echo "$a<$b"

exit 0

}

</pre>

第二个

<pre class="brush:shell">#!/bin/bash

#read -t 30 -p "pls input two num:" a b

#[ ${#a} -eq 0 -o ${#b} -eq 0 ]&&{

# echo "you need input two num"

# exit 1

[ $# -ne 2 ]&&{

echo "USAGE:$0 INT1 INT2"

exit 1

}

a=$1

b=$2

expr $a + 1 &>/dev/null

RETVAL_A=$?

expr $b + 1 &>/dev/null

RETVAL_B=$?

[ $RETVAL_A -ne 0 -o $RETVAL_B -ne 0 ]&&{

echo "one of your input is not int."

exit 1

}

if [ $a -eq $b ]

then

echo "$a=$b"

elif [ $a -gt $b ]

then

echo "$a>$b"

else

echo "$a<$b"

</pre>

打印选择菜单，一键安装Web服务：

[[email protected]]# sh menu.sh

1.[install lamp]

2.[install lnmp]

3.[exit]

pls input the num you want:

要求：

1、当用户输入1时，输出“startinstalling lamp.”然后执行/server/scripts/lamp.sh，脚本内容输出"lampis installed"后退出脚本；

2、当用户输入2时，输出“startinstalling lnmp.”然后执行/server/scripts/lnmp.sh输出"lnmpis installed"后退出脚本;

3、当输入3时，退出当前菜单及脚本；

4、当输入任何其它字符，给出提示“Input error”后退出脚本。

5、要对执行的脚本进行相关条件判断，例如：脚本是否存在，是否可执行等。

<strong>本题只是一个简单案例，练习cat的使用</strong>

<pre class="brush:shell">#!/bin/bash

menu(){

cat <<END

1.[install lamp]

2.[install lnmp]

3.[exit]

pls input the num you want:

END

}

read -t 15 a

[ $a -eq 1 ]&&{

echo "installing lamp"

sleep 3

echo "lamp is installed."

exit

}

[ $a -eq 2 ]&&{

echo "installing lnmp"

sleep 3

echo "lnmp is installed."

exit

}

[ $a -eq 3 ]&&{

exit

}

[ ! $a -eq 1 -o ! $a -eq 2 -o ! $a -eq 3 ] &&{

echo "bye"

exit 1

}

</pre>

<h1><a name="_Toc420786646"></a>13 检测web服务及mysql服务</h1>

1、监控web服务是否正常，不低于3种监控策略。

2、监控db服务是否正常，不低于3种监控策略。

要求间隔1分钟，持续监控。

本题只是给出解决问题的思路，写的比较简单和仓促，不代表生产环境脚本

<strong>检测web</strong>

<pre class="brush:shell">[[email protected] 0502]# cat web_curl.sh

#!/bin/sh

while true

NGINX_NU=`curl -I -s -w "%{http_code}" -o /dev/null 192.168.235.129`

if [ "${NGINX_NU}" == "200" ]

then

echo "nginx server is OK"

else

echo "nginx server is not ok"

sleep 1

done

[[email protected] 0502]# cat web_lsof.sh

#!/bin/sh

while true

NGINX_NU=`lsof -i:80|grep nginx|wc -l`

if [ ${NGINX_NU} -ge 2 ]

then

echo "nginx server is OK"

else

echo "nginx server is not ok"

sleep 1

done

[[email protected] 0502]# cat web_nmap.sh

#!/bin/sh

while true

NGINX_NU=`nmap 192.168.235.129 -p 80|grep open|wc -l`

if [ ${NGINX_NU} -eq 1 ]

then

echo "nginx server is OK"

else

echo "nginx server is not ok"

sleep 1

done

[[email protected] 0502]# cat web_ps.sh

#!/bin/sh

while true

NGINX_NU=`ps aux |grep nginx|wc -l`

if [ ${NGINX_NU} -ge 2 ]

then

echo "nginx server is OK"

else

echo "nginx server is not ok"

sleep 1

done

[[email protected] 0502]# cat web_wget.sh

#!/bin/sh

while true

wget --spider --timeout=10 --tries=2 192.168.235.129 >/dev/null 2>&1

if [ $? -eq 0 ]

then

echo "nginx server is OK"

else

echo "nginx server is not ok"

sleep 1

done

</pre>

<strong>检测mysql</strong>

<pre class="brush:shell">[[email protected] 0502]# cat mysql_lsof.sh

#!/bin/sh

while true

MYSQL_NU=`lsof -i:3306|wc -l`

if [ ${MYSQL_NU} -ge 2 ]

then

echo "mysql server is OK"

else

echo "mysql server is not ok"

sleep 1

done

[[email protected] 0502]# cat mysql_netstat.sh

#!/bin/sh

while true

MYSQL_NU=`netstat -lutup |grep mysql |wc -l`

if [ ${MYSQL_NU} -ge 1 ]

then

echo "mysql server is OK"

else

echo "mysql server is not ok"

sleep 1

done

[[email protected] 0502]# cat mysql_ps.sh

#!/bin/sh

while true

MYSQL_NU=`ps aux | grep mysql|wc -l`

if [ ${MYSQL_NU} -ge 2 ]

then

echo "mysql server is OK"

else

echo "mysql server is not ok"

sleep 1

done

[[email protected] 0502]# cat mysql_show.sh

#!/bin/sh

while true

mysql -uroot -p"123456" -S /data/3306/mysql.sock -e "show databases;" >/dev/null 2>&1

if [ $? -eq 0 ]

then

echo "mysql server is OK"

else

echo "mysql server is not ok"

sleep 1

done

</pre>

<h1><a name="_Toc420786647"></a>14 监控memcached</h1>

监控memcache服务是否正常，模拟用户（web客户端）检测。

使用nc命令加上set/get来模拟检测，以及监控响应时间及命中率。

脚本写的比较屎，像一坨，也是，这里只给出方法

<pre class="brush:shell">#!/bin/sh

while true

mem=`lsof -i:11211|wc -l`

if [ $mem -gt 1 ]

then

printf "set key_test 0 0 4\r\ntest\r\n"|nc 127.0.0.1 11211 >/dev/null 2>&1

value1=`echo $?`

printf "get key_test\r\n"|nc 127.0.0.1 11211 >/dev/null 2>&1

value2=`echo $?`

printf "delete key_test\r\n"|nc 127.0.0.1 11211 >/dev/null 2>&1

value3=`echo $?`

if [ $value1 -eq 0 -a $value2 -eq 0 -a $value3 -eq 0 ]

then

# echo "$(date +‘%F %H:%M‘) memcached server is ok" >>/opt/memcached.log

else

echo "$(date +‘%F %H:%M‘) memcached server is error">> /opt/memcached_error1.log

mail -s "memcached is error" [email protected] </opt/memcached_error1.log

exit 1

else

echo "$(date +‘%F %H:%M‘) memcached server not start" >>/opt/memcached_error2.log

memcached -d -c 10240 -p 11211 -m 16 -P /var/run/memcached.pid -u root

[ $? -eq 0 ]&&{

echo "$(date +‘%F %H:%M‘) memcached server start now" >> /opt/memcached_error2.log

}||{

echo "$(date +‘%F %H:%M‘) memcached server start filed, pls dispose" >> /opt/memcached_error2.log

mail -s "memcached start filed" [email protected] </opt/memcached_error2.log

exit 1

}

sleep 5

done

</pre>

<h1><a name="_Toc420786648"></a>15 监控web站点目录是否被篡改</h1>

监控web站点目录（/var/html/www）下所有文件是否被恶意篡改（文件内容被改了），如果有就打印改动的文件名（发邮件），定时任务每3分钟执行一次(10分钟时间完成)。

方法一，使用inotify方法，这里不再写脚本，很简单

<pre class="brush:shell">wget http://github.com/downloads/rvoicilas/inotify-tools/inotify-tools-3.14.tar.gz

tar zxf inotify-tools-3.14.tar.gz

cd inotify-tools-3.14

./configure --prefix=/usr/local/inotify-tools-3.14

make && make install

ln -s /usr/local/inotify-tools-3.14 /usr/local/inotify-tools

/usr/local/inotify-tools-3.14/bin/inotifywait -mrq --timefmt ‘%d/%m/%y %H:%M‘ --format ‘%T %w%f‘ -e create,delete /backup

</pre>

方法二，使用md5校对（注：感谢张耀同学的思路分享！）

<pre class="brush:shell">#!/bin/bash

DIR=/var/html/www

DBDIR=/server

md5db=$DBDIR/md5.db

newdb=$DBDIR/new.db

diffdb=$DBDIR/diff.db

checklog=/tmp/check.log

[ ! -d "$DIR" ]&&{

echo "This is not web"

exit 1

}

[ ! -d "$DBDIR" ] && mkdir $DBDIR -p

for i in $dm5db $newdb $diffdb $checklog

[ ! -d "$i" ] && touch $i

done

while true

md5sum -c $md5db|grep FAILED >>$checklog 2>&1

find $DIR -type f >$newdb

diff $newdb $diffdb >>$checklog 2>&1

[ -s "$checklog" ] && \

# mail -s "web check $(date +%F)" [email protected] <$checklog

echo haha

sleep 300

done

</pre>

<h1><a name="_Toc420786649"></a>16 rsync服务启动脚本</h1>

写网络服务独立进程模式下rsync的系统启动脚本

例如：/etc/init.d/rsyncd{start|stop|restart} 。

要求：

1.要使用系统函数库技巧。

2.要用函数，不能一坨SHI的方式。

3.可被chkconfig管理。

<pre class="brush:shell">#!/bin/bash

# chkconfig: 2345 31 61

# description: start rsync and stop rsync scripts.

#lixinyu linux

#2015-5-15

. /etc/init.d/functions

PID_FILE=/var/run/rsyncd.pid

rsync_start(){

if [ -f $PID_FILE ]

then

action "rsync is running" /bin/false

else

rsync --daemon

if [ $? -eq 0 ]

then

sleep 1

action "rsync is start" /bin/true

else

action "rsync is start" /bin/false

}

rsync_stop(){

if [ -f $PID_FILE ]

then

kill -USR2 `cat $PID_FILE`

if [ $? -eq 0 ]

then

rm -rf $PID_FILE

sleep 1

action "rsync is stop" /bin/true

else

action "rsync is stop" /bin/false

else

action "rsync is stoping" /bin/false

}

USAGE(){

echo "USAGE:$0 {start|stop|restart}"

exit 1

}

[ $# -ne 1 ]&&{

USAGE

}

case $1 in

start)

rsync_start

RETVAL=$?

;;

stop)

rsync_stop

RETVAL=$?

;;

restart)

rsync_stop

rsync_start

RETVAL=$?

;;

USAGE

esac

exit $RETVAL

</pre>

有N个学生，选出其中三个参加实践

要求：

1、执行脚本后，想去的同学输入英文名字全拼，产生随机数01-99之间的数字，数字越大就去参加项目实践，前面已经抓到的数字，下次不能在出现相同数字。

2、第一个输入名字后，屏幕输出信息，并将名字和数字记录到文件里，<strong>程序不能退出继续等待别的学生输入</strong>。

此题的思路详解如下：

http://www.z-dig.com/the-lottery-of-shell-script-example.html

<pre class="brush:shell">#!/bin/bash

file=name_file.db

if [ ! -f $file ]

then

touch $file

else

>$file

function ran_num(){

while true

random=$(($RANDOM%99+1))

if [ -z `egrep $random $file|awk ‘{print $2}‘` ]

then

break

done

}

function lot(){

read -p "pls write you name:" name empty

[ ${#name} -eq 0 ]&&{

echo "Please enter one name"

continue

}

[ ${#empty} -ne 0 ]&&{

echo "Please enter one name"

continue

}

[ "$name" = "exit" ]&&{

echo "bey dear"

exit 0

}

ran_num

if [ -z `egrep $name $file|awk ‘{print $1}‘` ]

then

echo "This time obtain random number is:"

echo "$name $random"

echo "$name $random" >>$file

else

echo "This time obtain random number is:"

egrep $name $file

}

function output(){

lot

echo "The random number of the top three:"

sort -rn -k2 $file|head -3

[ `cat $file|wc -l` -eq 99 ]&&{

echo "random number not have,bye dear"

exit 0

}

function main(){

while true

output

done

}

main

</pre>

<h1><a name="_Toc420786651"></a>18 暴力破解密码</h1>

已知下面的字符串是通过RANDOM随机数变量md5sum|cut-c 1-8截取后的结果，请破解这些字符串对应的md5sum前的RANDOM对应数字？

21029299

00205d1c

a3da1677

1f6d12dd

首先要知道RANDOM变量获取的随机数为0-32767之间

<pre class="brush:shell">#!/bin/bash

md5=(

21029299

00205d1c

a3da1677

1f6d12dd

)

for ((n=0;n<32768;n++))

for ((i=0;i<${#md5[*]};i++))

if [ "`echo $n|md5sum|cut -c 1-8`" == "${md5[i]}" ]

then

echo ${md5[i]} $n

done

</pre>

00205d1c 1346

1f6d12dd 7041

a3da1677 25345

21029299 25667

<h1><a name="_Toc420786652"></a>19 批量检查多个网站地址是否正常</h1>

要求：shell数组方法实现，检测策略尽量模拟用户访问思路

http://www.etiantian.org

http://www.taobao.com

http://oldboy.blog.51cto.com

http://10.0.0.7

<pre class="brush:shell">#!/bin/bash

. /etc/init.d/functions

url=(

http://www.etiantian.org

http://www.taobao.com

http://oldboy.blog.51cto.com

http://192.168.235.129

http://192.168.235.11

http://192.168.235.12

)

while_url(){

i=0

while [ $i -lt ${#url[*]} ]

wget --spider --timeout=10 --tries=2 ${url[$i]} &>/dev/null

if [ $? -eq 0 ]

then

action "${url[$i]}" /bin/true

else

action "${url[$i]}" /bin/false

((i++))

done

}

while true

while_url

sleep 1

done

</pre>

时间： 2024-10-02 09:21:50

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