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老男孩Shell企业面试题30道附答案

发布时间:2016年09月13日评论数：抢沙发阅读数：7782

企业面试题1：

（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）

[root@oldboy~]# mysql -uroot -p'oldboy' -S /data/3307/mysql.sock -e "show slavestatus\G;"

*************************** 1. row ***************************

Slave_IO_State:Waiting for master to send event

Master_Host:10.0.0.179 #当前的mysql master服务器主机

Master_User: rep

Master_Port: 3306

Connect_Retry: 60

Master_Log_File:mysql-bin.000013

Read_Master_Log_Pos: 502547

Relay_Log_File:relay-bin.000013

Relay_Log_Pos:251

Relay_Master_Log_File:mysql-bin.000013

Slave_IO_Running:Yes

Slave_SQL_Running: Yes

Replicate_Do_DB:

Replicate_Ignore_DB: mysql

Replicate_Do_Table:

Replicate_Ignore_Table:

Replicate_Wild_Do_Table:

Replicate_Wild_Ignore_Table:

Last_Errno: 0

Last_Error:

Skip_Counter: 0

Exec_Master_Log_Pos: 502547

Relay_Log_Space:502986

Until_Condition:None

Until_Log_File:

Until_Log_Pos: 0

Master_SSL_Allowed: No

Master_SSL_CA_File:

Master_SSL_CA_Path:

Master_SSL_Cert:

Master_SSL_Cipher:

Master_SSL_Key:

Seconds_Behind_Master: 0 #和主库比同步延迟的秒数，这个参数很重要

Master_SSL_Verify_Server_Cert: No

Last_IO_Errno: 0

Last_IO_Error:

Last_SQL_Errno: 0

Last_SQL_Error:

本脚本由李佳豪同学分享

[root@db02 tmp]# cat MySQL主从监控.sh

#!/bin/bash

Mysql="mysql -uroot -poldboy123 -S /data/3307/mysql.sock"

L_aaa(){

Status=`$Mysql -e "show slave status\G" | grep -E "_Running: Yes|Seconds_Behind_Master: [0-2]" | wc -l`

Code=`$Mysql -e "show slave status\G" | awk '/Last_SQL_Errno:/{print $2}'`

}

L_Status(){

[ $Status -ne 3 ] && {

return 1

} || {

return 0

}

S_Code=(

1158

1159

1008

1007

1062

)

L_Skip(){

[ $Code -eq 0 ] && return 0

for i in ${S_Code[*]}

[ $Code -eq $i ] && {

$Mysql -e "stop slave;set global sql_slave_skip_counter = 1;start slave;" && \

return 0

}

done

return 1

}

main(){

while true

L_aaa

L_Skip

Error1=$?

L_Status

Error2=$?

[ $Error1 -eq 1 -o $Error2 -eq 1 ] && echo "Error"

done

}

main

企业面试题2：

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：

[root@oldboy oldboy]# sh /server/scripts/oldboy.sh

[root@oldboy oldboy]# ls

coaolvajcq_oldboy.html qnvuxvicni_oldboy.html vioesjmcbu_oldboy.html

gmkhrancxh_oldboy.html tmdjormaxr_oldboy.html wzewnojiwe_oldboy.html

jdxexendbe_oldboy.html ugaywanjlm_oldboy.html xzzruhdzda_oldboy.html

qcawgsrtkp_oldboy.html vfrphtqjpc_oldboy.html

脚本如下：

[root@db02 ~]# sh html.sh

[root@db02 ~]# ls /oldboy/

aebccciiaj_oldboy.html fffabecgbc_oldboy.html

afffebcchb_oldboy.html ffghcffegb_oldboy.html

dbccddabbj_oldboy.html hffbhfgdff_oldboy.html

ehbdaedach_oldboy.html jadafhbaaf_oldboy.html

fbaacihehi_oldboy.html jgfebjbebd_oldboy.html

[root@db02 ~]# cat html.sh

#!/bin/bash

. /etc/init.d/functions

[ -d /oldboy ]|| mkdir -p /oldboy

cd /oldboy

for i in `seq 10`

touch `echo $RANDOM|md5sum|cut -c 1-10|tr "[0-9]" "[a-z]"`_oldboy.html

done

企业面试题3：

请用至少两种方法实现！

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。

第一种方法：

[root@db02 ~]# sh html1.sh

[root@db02 ~]# ll /oldboy/

total 0

-rw-r--r-- 1 root root 0 Jul 20 20:45 aebccciiaj_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 afffebcchb_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 dbccddabbj_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 ehbdaedach_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 fbaacihehi_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 fffabecgbc_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 ffghcffegb_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 hffbhfgdff_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 jadafhbaaf_oldboy.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 jgfebjbebd_oldboy.HTML

[root@db02 ~]# cat html1.sh

#!/bin/bash

cd /oldboy

for i in `cd /oldboy`

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

done

第二种方法：

[root@db02 ~]# sh html2.sh

[root@db02 ~]# ll /oldboy/

total 0

-rw-r--r-- 1 root root 0 Jul 20 20:45 aebccciiaj_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 afffebcchb_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 dbccddabbj_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 ehbdaedach_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 fbaacihehi_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 fffabecgbc_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 ffghcffegb_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 hffbhfgdff_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 jadafhbaaf_oldgirl.HTML

-rw-r--r-- 1 root root 0 Jul 20 20:45 jgfebjbebd_oldgirl.HTML

[root@db02 ~]# cat html2.sh

#!/bin/bash

cd /oldboy

for i in `ls *.HTML`

mv $i `echo $i|sed -e 's#oldboy#oldgirl#g;s#html#HTML#g'`

done

补充：QQ 1163718639

[root@db01 shell30]# cat 3.sh

#!/bin/bash

for i in /oldboy/* do rename oldboy. oldgir. $i|echo oldgirlok done for x in /oldboy/* do rename html HTML $x|echo htmlok done

[root@db01 shell30]#

企业面试题4：

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）。

[root@db02 tmp]# cat useradd.sh

#!/bin/bash

[ $UID -ne 0 ]&& echo "only root run"&&exit 1

[ -f /etc/init.d/functions ]&& . /etc/init.d/functions

isexist() {

result=$(grep -w "^$1" /etc/passwd|wc -l)

if [ $result -ne 0 ];then

echo "user $1 is exist!!"

ret 1 "create user is "

continue

}

ret() {

if [ $1 -eq 0 ];then

action "$2" /bin/true

else

action "$2" /bin/false

}

create() {

for i in $(seq -w 10)

user="oldboy$i"

isexist $user

pass=$(cat /proc/sys/kernel/random/uuid|md5sum|cut -c 1-10)

useradd $user&&echo $pass|passwd --stdin $user &>/dev/null

ret $? "crate user $user"

echo "$user $pass" >> /tmp/user.list

done

}

main() {

create

}

main

企业面试题5：

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）

本脚本由刘沈晨分享

注意：此脚本使用nmap，如果没有需要使用yum -y install nmap

[root@db02 scripts]# cat test_5.sh

#!/bin/sh

[ -f /etc/init.d/functions ] && . /etc/init.d/functions

function IP_count(){

for n in 10.0.0.{0..255}

IP_check=`nmap -sP $n|grep "Host is up"|wc -l`

if [ ${IP_check} -eq 1 ];then

action "$n" /bin/true

let i+=1

done

}

function main(){

IP_count

echo "The total number of online IP Addresses is " $i

}

main

企业实战题6：

写一个脚本解决DOS攻击生产案例

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 -I INPUT -s 10.0.1.10 -j DROP。

本脚本使用测试文件进行编写：模拟文件下载链接：http://pan.baidu.com/s/1gfqeHaz 密码：3usn

[root@db02 scripts]# cat test_6.sh

#!/bin/sh

[ -f /etc/init.d/functions ] && . /etc/init.d/functions

IP_file="/server/scripts/ddos.txt"

IP_filter_command="iptables -I INPUT -j DROP -s"

IP_recover_command="iptables -D INPUT -j DROP -s"

function IP_check(){

grep "EST" ${IP_file}|awk -F "[ |:]+" '{print $6}'|sort |uniq -c|sort -rn -k1 > /server/scripts/ip.txt

}

function IP_filter(){

exec < /server/scripts/ip.txt

while read line

IP_count=`echo $line|awk '{print $1}'`

IP=`echo $line|awk '{print $2}'`

IP_fil=`iptables -L -n|grep "\b${IP}\b"|wc -l`

if [ ${IP_count} -gt 25 -a ${IP_fil} -eq 0 ];then

${IP_filter_command} ${IP}

echo "${IP}" >> /server/scripts/ip_filtered.txt

action "Filter ${IP}" /bin/true

done

}

function IP_recover(){

exec < /server/scripts/ip.txt

while read line

IP_count=`echo $line|awk '{print $1}'`

IP=`echo $line|awk '{print $2}'`

IP_fil=`iptables -L -n|grep "\b${IP}\b"|wc -l`

if [ ${IP_count} -le 25 -a ${IP_fil} -eq 1 ];then

${IP_recover_command} ${IP}

echo "${IP}" >> /server/scripts/ip_filtered.txt

action "Recover ${IP}" /bin/true

done

}

function main(){

case "$1" in

filter)

IP_check

echo "$(date +%F-%H:%M:%S) filtered by $(whoami)" >> /server/scripts/ip_filtered.txt

IP_filter

;;

recover)

IP_check

echo "$(date +%F-%H:%M:%S) recovered by $(whoami)" >> /server/scripts/ip_filtered.txt

IP_recover

;;

echo "USAGE:$0 {filter|recover}"

exit 1

esac

}

main $*

企业实战题7：

开发mysql多实例启动脚本：

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

1.第一种方法：比较简单，适用于一台MySQL服务器上

[root@db02 mysql]# cat mysql.sh

#!/bin/bash

###########################

#I am YuhongCong

#qq:604419314

##########################

[ -f /etc/init.d/functions ]&& . /etc/init.d/functions

#config

prot=3306

mysql_user=root

mysql_paswd=123456

Path=/data/3306/

mysql_start(){

if [ -f ${Path}mysqld.pid ];then

echo "MySQL is running"

exit 1

else

mysqld_safe --defaults-file=${Path}my.cnf &>/dev/null &

if [ $? -eq 0 ];then

action "MySQL is starting" /bin/true

else

action "MySQL no start" /bin/false

}

mysql_stop(){

if [ ! -f ${Path}mysqld.pid ];then

echo "Mysql not running"

else

mysqladmin -u ${mysql_user} -p${mysql_paswd} -S ${Path}mysql.sock shutdown

if [ $? -eq 0 ];then

action "mysql is stop" /bin/true

else

action "mysql no stop" /bin/false

}

case "$1" in

start)

mysql_start

;;

stop)

mysql_stop

;;

restart)

mysql_stop

sleep 3

mysql_start

;;

echo "Please input {start|stop|restart}"

;;

esac

第二种方法：应强哥及李啸宇、大欣等要求进行改版。

适用于管理多实例启动的脚本

[root@db02 tmp]# cat mysqlgood.sh

#!/bin/bash

##################

#I am yuhongcong

#qq:604419314

#################

[ -f /etc/init.d/functions ]&& . /etc/init.d/functions

prot=3306

mysql_user=root

mysql_paswd=123456

Path=/data/3306/

#############################################

cat <<END

############################

# 3306

# 3307

# exit

###########################

END

read -p "Please input {3306|3307}" a

mysql1_start(){

if [ -f ${Path}mysqld.pid ];then

echo "MySQL is runningx"

else

mysqld_safe --defaults-file=${Path}my.cnf &>/dev/null &

if [ $? -eq 0 ];then

action "mysql 3306 is starting" /bin/true

else

action "mysql 3306 not start" /bin/false

}

mysql1_stop(){

if [ ! -f ${Path}mysqld.pid ];then

echo "mysql 3306 not running"

else

mysqladmin -u ${mysql_user} -p${mysql_paswd} -S /data/3306/mysql.sock shutdown

if [ $? -eq 0 ];then

action "mysql 3306 is stopping" /bin/true

else

action "mysql 3306 no stop" /bin/false

}

mysql2_start(){

if [ -f /data/3307/mysqld.pid ];then

echo "MySQL 3307 is runningx"

else

mysqld_safe --defaults-file=/data/3307/my.cnf &>/dev/null &

if [ $? -eq 0 ];then

action "mysql 3307 is starting" /bin/true

else

action "mysql 3307 not start" /bin/false

}

mysql2_stop(){

if [ ! -f /data/3307/mysqld.pid ];then

echo "mysql 3307 not running"

else

mysqladmin -u ${mysql_user} -p${mysql_paswd} -S /data/3307/mysql.sock shutdown

if [ $? -eq 0 ];then

action "mysql 3307 is stopping" /bin/true

else

action "mysql 3307 no stop" /bin/false

}

aaa(){

cat <<END

###########################

# 1.start

# 2.stop

# 3.restart

# 4.exit

###########################

END

read -p "please input {1|2|3|4}" b

}

bbb(){

cat <<END

###########################

# 1.start

# 2.stop

# 3.restart

# 4.exit

###########################

END

read -p "please input {1|2|3|4}" c

}

case "$a" in

3306)

aaa

;;

3307)

bbb

;;

exit)

exit

;;

esac

case "$b" in

mysql1_start

;;

mysql1_stop

;;

mysql1_stop

sleep 3

mysql1_start

;;

exit 2

;;

esac

case "$c" in

mysql2_start

;;

mysql2_stop

;;

mysql2_stop

sleep 3

mysql2_start

;;

exit 2

;;

esac

企业实战题8:

如何实现对MySQL数据库进行分库备份，请用脚本实现

本文由刘康同学提供

[root@db02 tmp]# cat MoreDatabasesBak.sh

#!/bin/bash

. /etc/init.d/functions

PORT='3306'

BAKUPDIR='/server/backup'

MYSQLUSER='root'

MYSQLPASS='oldboy'

SOCK="/data/${PORT}/mysql.sock"

CMDDIR="/application/mysql/bin"

MYSQL="${CMDDIR}/mysql -u${MYSQLUSER} -p${MYSQLPASS} -S${SOCK}"

DBNAME=`${MYSQL} -e "show databases;"|sed 1d|egrep -v "_schema|mysql"`

AYYAYDB=($DBNAME)

MYSQLDUMP="${CMDDIR}/mysqldump -u${MYSQLUSER} -p${MYSQLPASS} -S${SOCK}"

function BAKDB(){

for((n=0;n<${#AYYAYDB[*]};n++))

${MYSQLDUMP} --events -B ${AYYAYDB[$n]} |gzip >${BAKUPDIR}/${AYYAYDB[$n]}_$(date +%T-%F)_bak.sql.gz

RETVAL=$?

if [ $RETVAL -eq 0 ]

then

echo "${AYYAYDB[$n]} bak successfull `date +%F-%T` " >>/tmp/DBbakstatus.log

else

echo "${AYYAYDB[$n]} bak fail `date +%F-%T` " >>/tmp/DBbakstatus.log

done

mail -s "DB STATUS" www.abcdocker.com@qq.com < /tmp/DBbakstatus.log

return

}

function DBstatus(){

[ -d ${BAKUPDIR} ] || mkdir ${BAKUPDIR} -p

${MYSQL} -e "show full processlist;" &> /dev/null

RETVAL=$?

if [ $RETVAL -eq 0 ]

then

>/tmp/DBbakstatus.log

BAKDB

else

echo "DB BAD!!! `date +%F-%T`" | mail -s "DB BAD!!!" www.abcdocker.com@qq.com

exit

}

DBstatus

企业实战题9:

如何实现对MySQL数据库进行分库加分表备份，请用脚本实现

本脚本还是由刘康同学提供

[root@db02 tmp]# cat MoreTablesBak.sh

#!/bin/bash

. /etc/init.d/functions

PORT='3306'

BAKUPDIR='/server/backup'

MYSQLUSER='root'

MYSQLPASS='oldboy'

SOCK="/data/${PORT}/mysql.sock"

CMDDIR="/application/mysql/bin"

MYSQL="${CMDDIR}/mysql -u${MYSQLUSER} -p${MYSQLPASS} -S${SOCK}"

DBNAME=`${MYSQL} -e "show databases;"|sed 1d|egrep -v "_schema|mysql"`

AYYAYDB=($DBNAME)

MYSQLDUMP="${CMDDIR}/mysqldump -u${MYSQLUSER} -p${MYSQLPASS} -S${SOCK}"

function BAKDB(){

DBNAME=`${MYSQL} -e "show databases;"|sed 1d|egrep -v "_schema|mysql"`

AYYAYDB=($DBNAME)

for((n=0;n<${#AYYAYDB[*]};n++))

TABLE_BAK_DIR="${BAKUPDIR}/${AYYAYDB[$n]}"

TABLENAME=`${MYSQL} -e "show tables from ${AYYAYDB[$n]};"|sed 1d`

ARRAYTABLE=(${TABLENAME})

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

[ -d ${TABLE_BAK_DIR} ] || mkdir ${TABLE_BAK_DIR} -p

${MYSQLDUMP} ${AYYAYDB[$n]} ${ARRAYTABLE[$i]} |gzip >${TABLE_BAK_DIR}/${ARRAYTABLE[$i]}_$(date +%T-%F)_bak.sql.gz

RETVAL=$?

if [ $RETVAL -eq 0 ]

then

echo "${AYYAYDB[$n]}_${ARRAYTABLE[$i]} bak successfull `date +%F-%T` " >>/tmp/DB_table_bakstatus.log

else

echo "${AYYAYDB[$n]}_${ARRAYTABLE[$i]} bak fail `date +%F-%T` " >>/tmp/DB_table_bakstatus.log

done

mail -s "DB STATUS" www.abcdocker.com@qq.com < /tmp/DB_table_bakstatus.log

return

}

function DBstatus(){

[ -d ${BAKUPDIR} ] || mkdir ${BAKUPDIR} -p

${MYSQL} -e "show full processlist;" &> /dev/null

RETVAL=$?

if [ $RETVAL -eq 0 ]

then

>/tmp/DB_table_bakstatus.log

BAKDB

else

echo "DB BAD!!! `date +%F-%T`" | mail -s "DB BAD!!!" www.abcdocker.com@qq.com

exit

}

DBstatus

企业面试题10：

请用至少两种方法实现！

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.

没讲数组之前自己做的：

[root@web02 ~]# cat /server/scripts/28/bash.sh

#!/bin/bash

for n in `echo I am oldboy teacher welcome to oldboy training class.`

AAA=$( echo $n|wc -c)

if [ $AAA -gt 7 ];then

continue;

echo $n

done

第一种方法：不使用数组

[root@db02 scripts]# cat 3.sh

#!/bin/bash

for i in I am oldboy teacher welcome to oldboy training class.

if [ "${#i}" -le 6 ]

then

echo $i

done

第二种方法：使用数组

[root@db02 scripts]# cat 3.sh

#!/bin/bash

array=(I am oldboy teacher welcome to oldboy training class.)

for ((i=0;i<${#array[@]};i++))

if [ "`echo ${array[i]}|wc -L`" -le 6 ]

then

echo ${array[i]}

done

第三种方法：命令拼接

echo "I am oldboy teacher welcome to oldboy training class." | awk '{for(i=1;i<=NF;i++){a=length($i);if(a <= 6){print $i}}}'

企业面试题11：

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。

[root@db01 scripts]# cat read.sh

#!/bin/sh

#no.1

read -p "Pls input two num:" a b

[ -z "$a" -o -z "$b" ]&&{

echo "must be two num."

exit 1

}

#no.2

expr $a + 1 &>/dev/null

[ $? -ne 0 ]&&{

echo "First arg must be int."

exit 2

}

expr $b + 1 &>/dev/null

[ $? -ne 0 ]&&{

echo "Second arg must be int."

exit 3

}

#no.3

[ $a -gt $b ]&&{

echo "$a > $b"

exit 0

}

[ $a -eq $b ]&&{

echo "$a = $b"

exit 0

}

[ $a -lt $b ]&&{

echo "$a < $b"

exit 0

}

企业面试题12：

打印选择菜单，一键安装Web服务：

[root@oldboyscripts]# 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。

由10组黑哥提供（吴依）

黑哥博客：www.dockerwy.com

#!/bin/bash

cat <<EOF

1.[install lamp]

2.[install lnmp]

3.[exit]

pls input the num you want:

EOF

read -p "please input number 1-3:" a

lamp() {

if [ -f /server/scripts/lamp.sh ];then

echo "startinstalling lamp."

sleep 2

sh /server/scripts/lamp.sh

else

echo "file does not exist"

exit 0

}

lnmp () {

if [ -f /server/scripts/lnmp.sh ];then

echo "startinstalling lnmp."

sleep 3

sh /server/scripts/lnmp.sh

else

echo "file does not exist"

exit 0

}

case $a in

lamp

;;

lnmp

;;

exit 0

;;

echo "pls input the num you want:"

;;

esac

企业面试题13：

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。

思路

1、监控的三种方式

通过进程名监控 ps -ef|grep name

通过端口监控 netstat -lntup|grep port/lsof -i:80

通过链接信息上的进程名 netstat -lntup|grep port

2、等待一分钟

3、后台执行 nohup

#!/bin/bash

[ -f /etc/init.d/functions ] && . /etc/init.d/functions

check_httpd(){

count=`ps -ef|grep nginx|grep -v grep|wc -l`

if [ "$count" -ne 0 ]

then

action "nginx is ok" /bin/true

else

action "nginx is dead" /bin/false

}

check_httpd_port(){

count=`netstat -lntup|grep 8080|wc -l`

if [ "$count" -ne 0 ]

then

action "nginx is ok" /bin/true

else

action "nginx is dead" /bin/false

}

企业面试题14：

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。

感谢乔飞翔同学的分享

[root@db02 scripts]# cat mem.sh

#!/bin/bash

########################

#date:2016-07-17 #

#author:fxqiao #

#QQ:827724746 #

#E-mail:qfx1995@163.com#

########################

#echo -ne "\033[0;33m"

echo -ne "\E[1;32m"

cat<<EOT

_oo0oo_

088888880

88" . "88

(| -_- |)

0\ = /0

___/'---'\___

.' \\\\| |// '.

/ \\\\||| : |||// \\

/_ ||||| -:- |||||- \\

| | \\\\\\ - /// | |

| \_| ''\---/'' |_/ |

\ .-\__ '-' __/-. /

___'. .' /--.--\ '. .'___

."" '< '.___\_<|>_/___.' >' "".

| | : '- \'.;'\ _ /';.'/ - ' : | |

\ \ '_. \_ __\ /__ _/ .-' / /

====='-.____'.___ \_____/___.-'____.-'=====

'=---='

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

佛祖保佑 iii 服务正常

EOT

echo -ne "\E[0m"

[ -f /etc/init.d/functions ] && . /etc/init.d/functions

###variables

RETVAL=0

###color

RED_COLOR='\E[1;31m'

GREEN_COLOR='\E[1;32m'

YELLOW_COLOR='\E[1;33m'

BLUE_COLOR='\E[1;34m'

RES='\E[0m'

####menu list

menu() {

cat <<EOF

############################

1 memcached status

2 memcached stop

3 memcached get_hits

4 quit

EOF

}

status() {

Set=$(printf "set key1 0 0 6\r\noldboy\r\n"|nc 127.0.0.1 11211|grep STORED|wc -l)

Get=$(printf "get key1\r\n"|nc 127.0.0.1 11211|grep oldboy|wc -l)

Port=$(netstat -lntup|grep memcached|wc -l)

if [ $Port -ge 4 ];then

Num=$(expr $Set + $Get)

if [ $Num -eq 2 ];then

action "Memcached server is running" /bin/true

else

action "Memcached server is not normal" /bin/false

else

action "Memcached server is not running" /bin/false

read -t 10 -p "Memcached server whether open:

:" b

if [ "$b" == "y" -o "$b" == "Y" ];then

/usr/bin/memcached -m 16m -p 11211 -d -u root -c 8192

action "Memcached server is starting" /bin/true

elif [ "$b" == "n" -o "$b" == "N" ];then

echo -e "$YELLOW_COLOR Goodbye.............$RES"

return $RETVAL

}

stop() {

Port=$(netstat -lntup|grep memcached|wc -l)

if [ $Port -ge 4 ];then

pkill memcached &>/dev/null

RETVAL=$?

if [ $RETVAL -eq 0 ];then

action "Memcached server is stopping" /bin/true

else

action "Memcached server is stopping" /bin/false

else

action "Memcached server not running" /bin/false

}

get_hits() {

Cmd_get=$(printf "stats\r\n"|nc 127.0.0.1 11211|grep "cmd_get"|awk '{print $3}')

Get_hits=$(printf "stats\r\n"|nc 127.0.0.1 11211|grep "get_hits"|awk '{print $3}')

Get_misses=$(printf "stats\r\n"|nc 127.0.0.1 11211|grep "get_misses"|awk '{print $3}')

Port=$(netstat -lntup|grep memcached|wc -l)

if [ $Port -ge 4 ];then

echo "A total of cmd_get is $Cmd_get"

sleep 1

echo "A total of get_hits is $Get_hits"

sleep 1

echo "A total of get_misses is $Get_misses"

else

action "Memcached is not running" /bin/false

return $RETVAL

}

main() {

while true

read -t 10 -p "Please input number:" a

expr $a + 1 &>/dev/null

if [ $? -ne 0 ];then

echo -e "$BLUE_COLOR Please input error,not int $RES"

exit 1

case "$a" in

status

RETVAL=$?

;;

stop

RETVAL=$?

;;

get_hits

RETVAL=$?

;;

clear

echo "##############################################"

echo -e "$GREEN_COLOR `figlet GoodBye` $RES"

echo "##############################################"

exit 0

;;

echo -e "$RED_COLOR input error $RES"

esac

done

}

main

exit $RETVAL

企业面试题15：

面试及实战考试题：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)。

[root@db02 tmp]# cat html.sh

#!/bin/sh

html_dir=/var/html/www

html_file=`find /var/html/www -type f`

check_dir=/tmp/checkdir

[ ! -d $check_dir ] && mkdir $check_dir

for n in $html_file

md5sum $n >>$check_dir/1.txt

done

while true

md5sum -c $check_dir/1.txt|grep FAILED >>$check_dir/2.txt

[ -s $check_dir/2.txt ] && \

echo "`cat $check_dir/2.txt`"|mail -s "date:`date +%F-%H:%M:%S` Web is dangerous" 18576749166@163.com

>$check_dir/2.txt

sleep 3

done

企业面试题16：

企业案例: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。

[root@www tmp]# cat 123.sh

#!/bin/bash

##################

#I am yuhongcong

#qq:604419314

#################

# Comments to support chkconfig on RedHat Linux

# chkconfig: 2345 64 36

status1=$(ps -ef | egrep "rsync --daemon.*rsyncd.conf" | grep -v 'grep')

pidfile="/etc/rsync/rsyncd.pid"

start_rsync="rsync --daemon --config=/etc/rsync/rsyncd.conf"

function rsyncstart() {

if [ "${status1}X" == "X" ];then

rm -f $pidfile

${start_rsync}

status2=$(ps -ef | egrep "rsync --daemon.*rsyncd.conf" | grep -v 'grep')

if [ "${status2}X" != "X" ];then

echo "rsync service start.......OK"

else

echo "rsync service is running !"

}

function rsyncstop() {

if [ "${status1}X" != "X" ];then

kill -9 $(cat $pidfile)

status2=$(ps -ef | egrep "rsync --daemon.*rsyncd.conf" | grep -v 'grep')

if [ "${statusw2}X" == "X" ];then

echo "rsync service stop.......OK"

else

echo "rsync service is not running !"

}

function rsyncstatus() {

if [ "${status1}X" != "X" ];then

echo "rsync service is running !"

else

echo "rsync service is not running !"

}

function rsyncrestart() {

if [ "${status1}X" == "X" ];then

echo "rsync service is not running..."

rsyncstart

else

rsyncstop

rsyncstart

}

case $1 in

"start")

rsyncstart

;;

"stop")

rsyncstop

;;

"status")

rsyncstatus

;;

"restart")

rsyncrestart

;;

echo

echo "Usage: $0 start|stop|restart|status"

echo

esac

企业面试题17：

老男孩教育天津项目学生实践抓阄题目：

好消息，老男孩培训学生外出企业项目实践机会（第6次）来了（本月中旬），但是，名额有限，队员限3人（班长带队）。

因此需要挑选学生，因此需要一个抓阄的程序：

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，程序不能退出继续等待别的学生输入。

[root@db02 tmp]# cat select17.sh

#!/bin/sh

> /tmp/temp.txt

input(){

while true

read -p "pls input your name:" name

if [ -z $name ]

then

continue

elif [ $name == "0" ]

then

break

rand=$((RANDOM%100))

echo -e $rand"\t"$name >>/tmp/temp.txt

done

}

output(){

cat /tmp/temp.txt |sort -n -k1 -r|sed '3a#################'

}

main(){

input

output

}

main

企业面试题18：

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

890684b

方法一：

#!/bin/bash

. /etc/init.d/functions

MD5PASS=(

21029299

00205d1c

a3da1677

1f6d12dd

890684b

)

for ((n=0;n<=32767;n++))

for((i=0;i<${#MD5PASS[*]};i++))

md5=`echo $n | md5sum|cut -c 1-8`

if [ "$md5" == ${MD5PASS[$i]} ]

then

echo "$n" "${MD5PASS[$i]} "

done

方法二：

[root@openvpn-server ~]# cat md5sum.sh

#!/bin/sh

a=(

21029299

00205d1c

a3da1677

1f6d12dd

890684b

)

for i in `seq 32767`

source=`echo $i|md5sum|cut -c 1-8`

for j in ${a[@]}

if [ $source == $j ];then

echo $source "-->" $i

done

方法三：

[root@m01 ~]# cat mianshiti6.sh

#!/bin/bash

mima=(

21029299

00205d1c

a3da1677

1f6d12dd

890684b

)

for i in {1..32767}

num=`echo $i | md5sum | cut -c -8`

for n in ${mima[*]}

if [ "$num" == "$n" ]

then

echo "$i match $n"

continue

done

企业面试题19：

批量检查多个网站地址是否正常

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

[root@db02 scripts]# cat aaa.sh

#!/bin/sh

################

#Author:YuHongCong

#604419314@qq.com

################

[ -f /etc/init.d/functions ] && . /etc/init.d/functions

URLS=(

http://www.etiantian.org

http://www.taobao.com

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

http://10.0.0.70

)

CHECK_URL(){

wget -T 3 --spider --tries=2 $1 &>/dev/null

if [ $? -eq 0 ]

then

return 0

else

return 1

}

MON_URL(){

for url in ${URLS[*]}

CHECK_URL $url

if [ $? -eq 0 ]

then

action "$url" /bin/true

else

action "$url" /bin/false

done

}

main(){

while true

MON_URL

sleep 10

done

}

main

1.png-178kB

老男孩推荐：（包含倒计时的方法）

[root@db01 shizhan]# cat oldboy01.sh

#!/bin/sh

################

#Author:oldboy

#31333741@qq.com

################

[ -f /etc/init.d/functions ] && . /etc/init.d/functions

URLS=(

http://www.etiantian.org

http://www.taobao.com

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

http://10.0.0.70

)

LTIME(){

echo -n "time;"

for n in {1..10}

if [ $n -eq 10 ]

then

echo "start"

else

echo -n .

sleep 1

done

}

CHECK_URL(){

wget -T 3 --spider --tries=2 $1 &>/dev/null

if [ $? -eq 0 ]

then

return 0

else

return 1

}

MON_URL(){

for url in ${URLS[*]}

CHECK_URL $url

if [ $? -eq 0 ]

then

action "$url" /bin/true

else

action "$url" /bin/false

done

}

main(){

while true

LTIME

MON_URL

sleep 10

done

}

main

企业面试题20(中企动力)：

用shell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 toassist users design,implement and support squid installations. Please browsethe documentation and support sections for more infomation

#!/bin/sh

str="the squid project provides a number of resources toassist users design,implement and support squid installations. Please browsethe documentation and support sections for more infomation"

words(){

}

letters(){

}

case $1 in

words)

words

;;

letters)

letters

;;

echo "usage:$0 {words|letters}"

esac

企业面试题22:

开发通过web界面展示监控Nginx代理节点状态，效果图如下。

2.png-376.9kB

文件打包密码：xso0

脚本及内容请下载

3.png-7.9kB

lvs+keepalived集群部分Shell企业案例：

企业面试题23、

【LVS主节点】手工开发ipvsadm管理lvs的脚本ip_vs

实现：/etc/init.d/lvs {start|stop|restart}

[root@www tmp]# cat lvs.sh

#!/bin/bash

if [ $UID -ne 0 ];then

echo "Permission denied (you must be root)"

exit 1

[ -f /etc/init.d/functions ] && . /etc/init.d/functions

vip_netmask=10.0.0.3/24

vip=10.0.0.3

service_addr=10.0.0.3:80

rs=(

10.0.0.7:80

10.0.0.8:80

)

start() {

#add vip

ifconfig|grep $vip &>/dev/null

if [ $? -ne 0 ];then

ip addr add $vip_netmask dev eth0 label eth0:0 && \

action "add vip $vip_netmask" /bin/true

else

echo "vip $vip_netmask already exists."

lvs_table=$(ipvsadm -ln|grep "$vip"|wc -l)

if [ $lvs_table -eq 1 ];then

echo "virtual server already exists."

else

#add virtual server

ipvsadm -A -t $service_addr -s wrr && \

action "add virtual server $service_addr" /bin/true

for ip in ${rs[@]};do

rs_num=$(ipvsadm -ln|grep "$ip"|wc -l)

if [ $rs_num -eq 1 ];then

echo "real server $ip already exists."

else

#add real server

ipvsadm -a -t $service_addr -r $ip -g -w 1 && \

action "add real server $ip" /bin/true

done

#set tcp tcpfin udp connection timeout

ipvsadm --set 30 5 60 && \

action "set tcp tcpfin udp connection timeout values." /bin/true

}

stop() {

ifconfig|grep $vip &>/dev/null

if [ $? -ne 0 ];then

echo "without vip $vip"

else

#delete vip

ip addr del $vip_netmask dev eth0 label eth0:0 && \

action "delete vip $vip_netmask." /bin/true

lvs_table=$(ipvsadm -ln|grep "$vip"|wc -l)

for ip in ${rs[@]};do

rs_num=$(ipvsadm -ln|grep "$ip"|wc -l)

let lvs_table+=rs_num

done

if [ $lvs_table -ge 1 ];then

#clear all table

ipvsadm -C && \

action "clear all lvs table." /bin/true

else

echo "lvs table is empty."

}

case "$1" in

start)

start

;;

stop)

stop

;;

restart)

stop

sleep 2

start

;;

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

esac

企业面试题24

【LVS主节点】模拟keepalived健康检查功能管理LVS节点，

当节点挂掉（检测2次，间隔2秒）从服务器池中剔除，好了（检测2次，间隔2秒）加进来

提示：利用ipvsadm命令实现添加和减少LVS节点。

[root@www tmp]# cat lvs_check_rs.sh

#!/bin/bash

vip=10.0.0.3

rs_ip=(

10.0.0.8

10.0.0.7

)

remove_check() {

for rs in ${rs_ip[@]};do

ipvsadm -ln|grep $rs &>/dev/null

if [ $? -eq 0 ];then

rs_donw=0

a_group_down=0

for i in 1 2;do

rs_down=$(nmap -p 80 $rs|grep open|wc -l)

let a_group_down+=rs_down

sleep 2

done

if [ $a_group_down -eq 0 ];then

ipvsadm -d -t ${vip}:80 -r ${rs}:80

done

}

join_check() {

for rs in ${rs_ip[@]};do

ipvsadm -ln|grep $rs &>/dev/null

if [ $? -ne 0 ];then

a_group_up=0

rs_up=0

for j in 1 2;do

rs_up=$(nmap -p 80 $rs|grep open|wc -l)

let a_group_up+=rs_up

sleep 2

done

if [ $a_group_up -eq 2 ];then

ipvsadm -a -t ${vip}:80 -r ${rs}:80 -g -w 1

done

}

check_rs() {

while true;do

remove_check

sleep 1

join_check

sleep 1

done

}

check_rs

企业面试题25

【LVS客户端节点】开发LVS客户端设置VIP以及抑制ARP的管理脚本

实现：/etc/init.d/lvsclient {start|stop|restart}

[root@web01-lnmp-09 scripts]# cat /etc/init.d/lvsclient

#!/bin/bash

#chkconfig: 2345 37 57

#Write by Bevin 2016

#LVS_Nginx

export PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

[ -f /etc/init.d/functions ] && source /etc/init.d/functions

#Step 1

function L_ipadd() {

VIPRES=`ip addr|grep 10.0.0.12|wc -l`

if [ $VIPRES -eq 0 ]

then

ip addr add 10.0.0.12/32 dev lo label lo:12

route add -host 10.0.0.12 dev lo

sleep 1

VIPRES=`ip addr|grep 10.0.0.12|wc -l`

if [ $VIPRES -eq 0 ]

then

ip addr add 10.0.0.12/32 dev lo label lo:12

route add -host 10.0.0.12 dev lo

sleep 1

VIPRES=`ip addr|grep 10.0.0.12|wc -l`

if [ $VIPRES -eq 0 ]

then

action "ip addr add 10.0.0.12/32 ..." /bin/false

exit 1

else

action "ip addr add 10.0.0.12/32 ..." /bin/true

else

action "ip addr add 10.0.0.12/32 ..." /bin/true

else

action "ip addr add 10.0.0.12/32 is exist."

echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore

echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce

echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore

echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce

}

function L_ipdel() {

VIPRES=`ip addr|grep 10.0.0.12|wc -l`

if [ $VIPRES -ne 0 ]

then

ip addr del 10.0.0.12/32 dev lo

route del -host 10.0.0.12 dev lo

sleep 1

VIPRES=`ip addr|grep 10.0.0.12|wc -l`

if [ $VIPRES -ne 0 ]

then

action "ip addr del 10.0.0.12/32 ..." /bin/false

exit 1

else

action "ip addr del 10.0.0.12/32 ..." /bin/true

else

action "ip addr del 10.0.0.12/32 ..." /bin/true

echo "0" > /proc/sys/net/ipv4/conf/lo/arp_ignore

echo "0" > /proc/sys/net/ipv4/conf/lo/arp_announce

echo "0" > /proc/sys/net/ipv4/conf/all/arp_ignore

echo "0" > /proc/sys/net/ipv4/conf/all/arp_announce

}

#Step 2

function L_exec() {

case "$1" in

start)

L_ipadd

;;

stop)

L_ipdel

;;

status)

VIPRES=`ip addr|grep 10.0.0.12|wc -l`

sleep 1

if [ $VIPRES -ne 0 ]

then

echo "LVS Nginx is working"

else

echo "LVS Nginx is not working"

;;

restart)

VIPRES=`ip addr|grep 10.0.0.12|wc -l`

if [ $VIPRES -ne 0 ]

then

L_ipdel

sleep 1

L_ipadd

else

echo "ip 10.0.0.12 is not working"

sleep 1

L_ipadd

;;

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

esac

}

企业面试题26

【LVS备节点】模拟keepalved vrrp功能，监听主节点，如果主节点不可访问则备节点启动并配置LVS实现接管主节点的资源提供服务（提醒：注意ARP缓存）

[root@lvs-lb01-05 scripts]# cat lvs.sh

#!/bin/bash

#Write by Bevin 2016

export PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

[ -f /etc/init.d/functions ] && source /etc/init.d/functions

#Step 1 Instal ip_vs

Ch_ipvs=`rpm -qa ipvsadm|wc -l`

if [ $Ch_ipvs -eq 0 ]

then

yum install ipvsadm -y

#Step 2 Functions

VIP=10.0.0.12

V_TAIL=12

RIP=(

)

function L_LVS_VIP_RIP() {

VIPRES=`ip addr|grep $VIP|wc -l`

if [ $VIPRES -eq 0 ]

then

ip addr add $VIP/24 dev eth0 label eth0:$V_TAIL

ipvsadm -C

ipvsadm -A -t $VIP:80 -s rr

for n in ${RIP[*]}

ipvsadm -a -t $VIP:80 -r 10.0.0.$n:80 -g

done

else

ipvsadm -C

ipvsadm -A -t $VIP:80 -s rr

for n in ${RIP[*]}

ipvsadm -a -t $VIP:80 -r 10.0.0.$n:80 -g

done

}

function L_check_vip() {

VIPRES=`ip addr|grep $VIP|wc -l`

if [ $VIPRES -eq 0 ]

then

L_LVS_VIP_RIP

sleep 5

if [ $VIPRES -eq 0 ]

then

L_LVS_VIP_RIP

sleep 5

if [ $VIPRES -eq 0 ]

then

echo "Warning: lb01: $VIP is down."|mail -s txbevin@sina.com

exit 1

sleep 5

}

function L_check_rip() {

for n in ${RIP[*]}

CurlRes=`curl -I -s 10.0.0.$n|grep -E "200|301|302"|wc -l`

if [ $CurlRes -ne 0 ]

then

RS=`ipvsadm -Ln|grep 10.0.0.$n|wc -l`

if [ $RS -eq 0 ]

then

ipvsadm -a -t $VIP:80 -r 10.0.0.$n:80

else

ipvsadm -d -t $VIP:80 -r 10.0.0.$n:80

mail -s "10.0.0.$n nginx is down at $(date +%F-%T)." txbevin@sina.com

continue

done

sleep 5

}

#Step 3

L_LVS_VIP_RIP

while true

L_check_vip

sleep 1

L_check_rip

sleep 1

done

后面几道题如果大家会可以把答案发送给我

mail:new_oldboy@163.com

－－－－－－－－－－－－－－－－－－－

企业面试题27

请用shell或Python编写一个正方形(oldboy_square.sh)，接收用户输入的数字。

例如：

[root@oldboy ~]# sh oldboy_square1.sh

Please Enter a number:5

++++++++++

[root@oldboy ~]# sh oldboy_square2.sh

Please Enter a number:9

■■■■■■■■■

企业面试题28

请用shell或Python编写一个等腰三角形(oldboy2_triangle.sh)，接收用户输入的数字。

例如：

[root@oldboy ~]# sh oldboy2_triangle.sh

Please Enter a number:5

***

*****

*******

*********

[root@oldboy ~]# sh oldboy2_triangle.sh

Please Enter a number:8

***

*****

*******

*********

***********

*************

***************

企业面试题29

请用shell或Python编写一个画直角梯形程序(oldboy4.sh)，接收用户输入的参数n，m

例如：

[root@oldboy ~]# sh oldboy4.sh 4 6

****

*****

******

27,28,29三道题可以参考

http://oldboy.blog.51cto.com/2561410/1718607

本文作者：Mr.linus 文章标题：老男孩Shell企业面试题30道附答案
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