@老男孩Shell企业面试题
shell
2016年9月7日
本文来自于老男孩教育,未经本人同意，禁止转载！否则追究法律责任。
原文：http://oldboy.blog.51cto.com/2561410/1632876
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[*]}
do
[ $Code -eq $i ] && {
$Mysql -e "stop slave;set global sql_slave_skip_counter = 1;start slave;" && \
return 0
}
done
return 1
}
main(){
while true
do
L_aaa
L_Skip
Error1=$?
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`
do
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` do 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` do 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
fi
}
ret() {
if [ $1 -eq 0 ];then
action "$2" /bin/true
else
action "$2" /bin/false
fi
}
create() {
for i in $(seq -w 10)
do
user="oldboy$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}
do
IP_check=`nmap -sP $n|grep "Host is up"|wc -l`
if [ ${IP_check} -eq 1 ];then
action "$n" /bin/true
let i+=1
fi
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
do
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
fi
done
}
function IP_recover(){
exec < /server/scripts/ip.txt
while read line
do
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
fi
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
fi
fi
}
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
fi
fi
}
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 </dev/null &
if [ $? -eq 0 ];then
action "mysql 3306 is starting" /bin/true
else
action "mysql 3306 not start" /bin/false
fi
fi
}
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
fi
fi
}
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
fi
fi
}
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 [ $? -eq 0 ];then
action "mysql 3307 is stopping" /bin/true
else
action "mysql 3307 no stop" /bin/false
fi
fi
}
aaa(){
cat <
企业实战题8:
如何实现对MySQL数据库进行分库备份，请用脚本实现
本文由刘康同学提供
[root@db02 tmp]# cat MoreDatabasesBak.sh
#!/bin/bash
. /etc/init.d/functions
PORT='3306'
BAKUPDIR='/server/backup'
MYSQLUSER='root'
MYSQLPASS='oldboy'
SOCK="/data/${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++))
do
${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
fi
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 [ $RETVAL -eq 0 ]
then
>/tmp/DBbakstatus.log
BAKDB
else
echo "DB BAD!!! `date +%F-%T`" | mail -s "DB BAD!!!" www.abcdocker.com@qq.com
exit
fi
}
DBstatus
企业实战题9:
如何实现对MySQL数据库进行分库加分表备份，请用脚本实现
本脚本还是由刘康同学提供
[root@db02 tmp]# cat MoreTablesBak.sh
#!/bin/bash
. /etc/init.d/functions
PORT='3306'
BAKUPDIR='/server/backup'
MYSQLUSER='root'
MYSQLPASS='oldboy'
SOCK="/data/${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<${#AYYAYDB[*]};n++))
do
TABLE_BAK_DIR="${BAKUPDIR}/${AYYAYDB[$n]}"
TABLENAME=`${MYSQL} -e "show tables from ${AYYAYDB[$n]};"|sed 1d`
ARRAYTABLE=(${TABLENAME})
for((i=0;i<${#ARRAYTABLE[*]};i++))
do
[ -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
fi
done
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 [ $RETVAL -eq 0 ]
then
>/tmp/DB_table_bakstatus.log
BAKDB
else
echo "DB BAD!!! `date +%F-%T`" | mail -s "DB BAD!!!" www.abcdocker.com@qq.com
exit
fi
}
DBstatus
企业面试题10：
请用至少两种方法实现！
bash for循环打印下面这句话中字母数不大于6的单词(昆仑万维面试题)。
I am oldboy teacher welcome to oldboy training class.
没讲数组之前自己做的：
[root@web02 ~]# cat /server/scripts/28/bash.sh
#!/bin/bash
for n in `echo I am oldboy teacher welcome to oldboy training class.`
do
AAA=$( echo $n|wc -c)
if [ $AAA -gt 7 ];then
continue;
fi
echo $n
done
第一种方法：不使用数组
[root@db02 scripts]# cat 3.sh
#!/bin/bash
for i in I am oldboy teacher welcome to oldboy training class.
do
if [ "${#i}" -le 6 ]
then
echo $i
fi
done
第二种方法：使用数组
[root@db02 scripts]# cat 3.sh
#!/bin/bash
array=(I am oldboy teacher welcome to oldboy training class.)
for ((i=0;i<${#array[@]};i++))
do
if [ "`echo ${array[i]}|wc -L`" -le 6 ]
then
echo ${array[i]}
fi
done
第三种方法：命令拼接
echo "I am oldboy teacher welcome to oldboy training class." | awk '{for(i=1;i<=NF;i++){a=length($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 < $b"
exit 0
}
企业面试题12：
打印选择菜单，一键安装Web服务：
[root@oldboyscripts]# sh menu.sh
1.[install lamp]
2.[install lnmp]
3.[exit]
pls input the num you want:
要求：
1、当用户输入1时，输出“startinstalling lamp.”然后执行/server/scripts/lamp.sh，脚本内容输出"lampis installed"后退出脚本；
2、当用户输入2时，输出“startinstalling lnmp.”然后执行/server/scripts/lnmp.sh输出"lnmpis installed"后退出脚本;
3、当输入3时，退出当前菜单及脚本；
4、当输入任何其它字符，给出提示“Input error”后退出脚本。
5、要对执行的脚本进行相关条件判断，例如：脚本是否存在，是否可执行等。
由10组黑哥提供（吴依）
黑哥博客：www.dockerwy.com
#!/bin/bash
cat <
企业面试题13：
1、监控web服务是否正常，不低于3种监控策略。
2、监控db服务是否正常，不低于3种监控策略。
要求间隔1分钟，持续监控。
思路
1、监控的三种方式
通过进程名监控 ps -ef|grep name
通过端口监控 netstat -lntup|grep port/lsof -i:80
通过链接信息上的进程名 netstat -lntup|grep port
2、等待一分钟
3、后台执行 nohup
#!/bin/bash
[ -f /etc/init.d/functions ] && . /etc/init.d/functions
check_httpd(){
count=`ps -ef|grep nginx|grep -v grep|wc -l`
if [ "$count" -ne 0 ]
then
action "nginx is ok" /bin/true
else
action "nginx is dead" /bin/false
fi
}
check_httpd_port(){
count=`netstat -lntup|grep 8080|wc -l`
if [ "$count" -ne 0 ]
then
action "nginx is ok" /bin/true
else
action "nginx is dead" /bin/false
fi
}
企业面试题14：
监控memcache服务是否正常，模拟用户（web客户端）检测。
使用nc命令加上set/get来模拟检测，以及监控响应时间及命中率。
感谢乔飞翔同学的分享
[root@db02 scripts]# cat mem.sh
#!/bin/bash
########################
#date:2016-07-17 #
#author:fxqiao #
#QQ:827724746 #
#E-mail:qfx1995@163.com#
########################
#echo -ne "\033[0;33m"
echo -ne "\E[1;32m"
cat<_/___.' >' "".
| | : '- \'.;'\ _ /';.'/ - ' : | |
\ \ '_. \_ __\ /__ _/ .-' / /
====='-.____'.___ \_____/___.-'____.-'=====
'=---='
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
佛祖保佑 iii 服务正常
EOT
echo -ne "\E[0m"
[ -f /etc/init.d/functions ] && . /etc/init.d/functions
###variables
RETVAL=0
###color
RED_COLOR='\E[1;31m'
GREEN_COLOR='\E[1;32m'
YELLOW_COLOR='\E[1;33m'
BLUE_COLOR='\E[1;34m'
RES='\E[0m'
####menu list
menu() {
cat <
############################
1 memcached status
2 memcached stop
3 memcached get_hits
4 quit
EOF
}
status() {
Set=$(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 [ $Num -eq 2 ];then
action "Memcached server is running" /bin/true
else
action "Memcached server is not normal" /bin/false
fi
else
action "Memcached server is not running" /bin/false
read -t 10 -p "Memcached server whether open:[y/n]:" b
if [ "$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"
fi
fi
return $RETVAL
}
stop() {
Port=$(netstat -lntup|grep memcached|wc -l)
if [ $Port -ge 4 ];then
pkill memcached &>/dev/null
RETVAL=$?
if [ $RETVAL -eq 0 ];then
action "Memcached server is stopping" /bin/true
else
action "Memcached server is stopping" /bin/false
fi
else
action "Memcached server not running" /bin/false
fi
}
get_hits() {
Cmd_get=$(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
fi
return $RETVAL
}
main() {
while true
do
menu
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 $RES"
exit 1
fi
case "$a" in
1)
status
RETVAL=$?
;;
2)
stop
RETVAL=$?
;;
3)
get_hits
RETVAL=$?
;;
4)
clear
echo "##############################################"
echo -e "$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
do
md5sum $n >>$check_dir/1.txt
done
while true
do
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 [ "${status2}X" != "X" ];then
echo "rsync service start.......OK"
fi
else
echo "rsync service is running !"
fi
}
function rsyncstop() {
if [ "${status1}X" != "X" ];then
kill -9 $(cat $pidfile)
status2=$(ps -ef | egrep "rsync --daemon.*rsyncd.conf" | grep -v 'grep')
if [ "${statusw2}X" == "X" ];then
echo "rsync service stop.......OK"
fi
else
echo "rsync service is not running !"
fi
}
function rsyncstatus() {
if [ "${status1}X" != "X" ];then
echo "rsync service is running !"
else
echo "rsync service is not running !"
fi
}
function rsyncrestart() {
if [ "${status1}X" == "X" ];then
echo "rsync service is not running..."
rsyncstart
else
rsyncstop
rsyncstart
fi
}
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
do
read -p "pls input your name:" name
if [ -z $name ]
then
continue
elif [ $name == "0" ]
then
break
fi
rand=$((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++))
do
for((i=0;i<${#MD5PASS[*]};i++))
do
md5=`echo $n | md5sum|cut -c 1-8`
if [ "$md5" == ${MD5PASS[$i]} ]
then
echo "$n" "${MD5PASS[$i]} "
fi
done
done
方法二：
[root@openvpn-server ~]# cat md5sum.sh
#!/bin/sh
a=(
21029299
00205d1c
a3da1677
1f6d12dd
890684b
)
for i in `seq 32767`
do
source=`echo $i|md5sum|cut -c 1-8`
for j in ${a[@]}
do
if [ $source == $j ];then
echo $source "-->" $i
fi
done
done
方法三：
[root@m01 ~]# cat mianshiti6.sh
#!/bin/bash
mima=(
21029299
00205d1c
a3da1677
1f6d12dd
890684b
)
for i in {1..32767}
do
num=`echo $i | md5sum | cut -c -8`
for n in ${mima[*]}
do
if [ "$num" == "$n" ]
then
echo "$i match $n"
continue
fi
done
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
fi
}
MON_URL(){
for url in ${URLS[*]}
do
CHECK_URL $url
if [ $? -eq 0 ]
then
action "$url" /bin/true
else
action "$url" /bin/false
fi
done
}
main(){
while true
do
MON_URL
sleep 10
done
}
main
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}
do
if [ $n -eq 10 ]
then
echo "start"
else
echo -n .
fi
sleep 1
done
}
CHECK_URL(){
wget -T 3 --spider --tries=2 $1 &>/dev/null
if [ $? -eq 0 ]
then
return 0
else
return 1
fi
}
MON_URL(){
for url in ${URLS[*]}
do
CHECK_URL $url
if [ $? -eq 0 ]
then
action "$url" /bin/true
else
action "$url" /bin/false
fi
done
}
main(){
while true
do
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(){
echo $str|sed 's#[^a-zA-Z]# #g'|tr " " "\n"|grep -v "^$"|sort|uniq -c|sort -r -n
}
letters(){
echo $str|grep -o "."|sort|egrep -v " |^$|[^a-zA-Z]"|uniq -c|sort -n -r
}
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。
文件打包 密码：xso0 脚本及内容请下载
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
fi
[ -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 $vip_netmask already exists."
fi
lvs_table=$(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
fi
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
fi
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 $vip_netmask." /bin/true
fi
lvs_table=$(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."
fi
}
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
fi
fi
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
fi
fi
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
fi
else
action "ip addr add 10.0.0.12/32 ..." /bin/true
fi
else
action "ip addr add 10.0.0.12/32 is exist."
fi
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
fi
else
action "ip addr del 10.0.0.12/32 ..." /bin/true
fi
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"
fi
;;
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
fi
;;
*)
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
fi
#Step 2 Functions
VIP=10.0.0.12
V_TAIL=12
RIP=(
9
10
)
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[*]}
do
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[*]}
do
ipvsadm -a -t $VIP:80 -r 10.0.0.$n:80 -g
done
fi
}
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
fi
fi
fi
sleep 5
}
function L_check_rip() {
for n in ${RIP[*]}
do
CurlRes=`curl -I -s 10.0.0.$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
fi
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
fi
done
sleep 5
}
#Step 3
L_LVS_VIP_RIP
while true
do
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
本文出自 “老男孩linux培训” 请务必保留此出处http://oldboy.blog.51cto.com/2561410/1632876
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