18道Shell高级编程企业实战题及参考答案

Shell高级编程企业实战题参考解答

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目录：

1、监控MySQL主从同步... 1

2、批量创建文件及改名... 3

3、批量创建用户随机密码... 6

4、判断网络主机存活... 7

5、解决DOS攻击生产案例... 7

6、MySQL启动脚本... 8

7、分库备份... 11

8、分库分表备份... 11

9、打印字母数不大于6的单词... 12

10、比较2个整数大小... 15

11、打印选择菜单... 17

12、监控web、db服务... 20

    12.1 监控web服务... 20

        12.1.1本地端口判断... 20

        12.1.2本地进程判断... 20

        12.1.3远程端口判断... 21

        12.1.4获取返回内容判断... 22

        12.1.5根据状态码判断... 22

    12.2 监控db服务... 23

        12.2.1插入与查询的值对比判断... 23

        12.2.2返回值判断... 24

        12.2.3本地端口对比... 24

        12.2.4本地进程判断... 25

        12.2.5远程端口判断... 25

13、监控memcache服务... 26

14、监控web站点目录... 27

15、rsync的系统启动脚本... 29

16、抽奖... 31

17、破解密码... 34

18、批量检查多个网站地址是否正常... 35

 

1、监控MySQL主从同步

企业面试题1：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）

 

模拟文本

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

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

3.                Slave_IO_State:Waiting formaster to send event

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

5.                   Master_User: rep

6.                   Master_Port: 3306

7.                 Connect_Retry: 60

8.               Master_Log_File:mysql-bin.000013

9.          Read_Master_Log_Pos: 502547

10.                Relay_Log_File:relay-bin.000013

11.                 Relay_Log_Pos:251

12.         Relay_Master_Log_File:mysql-bin.000013

13.              Slave_IO_Running:Yes

14.            Slave_SQL_Running: Yes

15.               Replicate_Do_DB:

16.          Replicate_Ignore_DB: mysql

17.           Replicate_Do_Table:

18.       Replicate_Ignore_Table:

19.      Replicate_Wild_Do_Table:

20. Replicate_Wild_Ignore_Table:

21.                    Last_Errno: 0

22.                    Last_Error:

23.                  Skip_Counter: 0

24.          Exec_Master_Log_Pos: 502547

25.               Relay_Log_Space:502986

26.               Until_Condition:None

27.                Until_Log_File:

28.                 Until_Log_Pos: 0

29.           Master_SSL_Allowed: No

30.           Master_SSL_CA_File:

31.           Master_SSL_CA_Path:

32.               Master_SSL_Cert:

33.            Master_SSL_Cipher:

34.                Master_SSL_Key:

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

36. Master_SSL_Verify_Server_Cert: No

37.                 Last_IO_Errno: 0

38.                 Last_IO_Error:

39.                Last_SQL_Errno: 0

40.                Last_SQL_Error:

  

脚本

                             

1. [root@shell scripts]# vicheck_mysql_slave.sh

2. #!/bin/sh

3. #2015-05-17

4. # Source function library.

5. . /etc/init.d/functions

6.   

7. # Defined variables

8. MysqlUser=root

9. MysqlPass=oldboy123

10. MysqlPort=3307

11. Mysqlsock=/data/$MysqlPort/mysql.sock

12. ErrorNo=(1158 1159 1008 10071062)

13. errorlog=/tmp/error_skip.log

14. MysqlCmd="/application/mysql/bin/mysql-u$MysqlUser -p$MysqlPass -S $Mysqlsock"

15.   

16. # Judge mysql server is ok?

17. [ -S $Mysqlsock ] ||{

18.     echo "Maybe MySQL have sometingwrong"

19.     exit 1

20. }

21.   

22. # Defined skip error Functions

23. function error_skip(){

24.     local flag

25.     flag=0

26.     for num in ${ErrorNo[@]}

27.       do

28.         if [ "$1" == "$num"];then

29.            $MysqlCmd -e'stop slave;set globalsql_slave_skip_counter=1;start slave;'

30.            echo "$(date +%F_%R) $1">>$errorlog

31.         else

32.            echo "$(date +%F_%R) $1">>$errorlog

33.            ((flag++))

34.         fi

35.     done

36.     [ "$flag" =="${#ErrorNo[@]}" ] &&{

37.         action "MySQL Slave"/bin/false

38.         uniq $errorlog|mail -s "MySQLSlave is error" [email protected]

39.     }

40. }

41.   

42. # Defined check slave Functions

43. function check_slave(){

44.     MyResult=`$MysqlCmd -e'show slavestatus\G'|egrep '_Running|Behind_Master|SQL_Errno' |awk '{print $NF}'`

45.     array=($MyResult)

46.     if [ "${array[0]}" =="Yes" -a "${array[1]}" == "Yes" -a"${array[2]}" == "0" ]

47.       then

48.         action "MySQL Slave"/bin/true

49.     else

50. error_skip ${array[3]}

51.     fi

52. }

53.   

54. # Defined main Functions

55. function main(){

56.     while true

57.        do

58.          check_slave

59.          sleep 60

60.     done

61. }

62. main

2、批量创建文件及改名 

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，批量创建10个html文件，名称例如为：

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

2. [root@oldboy oldboy]# ls -l

3. total 0

4. -rw-r--r-- 1 root root 0 Apr 1511:34 coaolvajcq_oldboy.html

5. -rw-r--r-- 1 root root 0 Apr 1511:34 gmkhrancxh_oldboy.html

6. -rw-r--r-- 1 root root 0 Apr 1511:34 jdxexendbe_oldboy.html

7. -rw-r--r-- 1 root root 0 Apr 1511:34 qcawgsrtkp_oldboy.html

8. -rw-r--r-- 1 root root 0 Apr 1511:34 qnvuxvicni_oldboy.html

9. -rw-r--r-- 1 root root 0 Apr 1511:34 tmdjormaxr_oldboy.html

10. -rw-r--r-- 1 root root 0 Apr 1511:34 ugaywanjlm_oldboy.html

11. -rw-r--r-- 1 root root 0 Apr 1511:34 vfrphtqjpc_oldboy.html

12. -rw-r--r-- 1 root root 0 Apr 1511:34 vioesjmcbu_oldboy.html

13. -rw-r--r-- 1 root root 0 Apr 1511:34 wzewnojiwe_oldboy.html

14. -rw-r--r-- 1 root root 0 Apr 1511:34 xzzruhdzda_oldboy.html

 

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。

 

1. 2.1批量创建脚本

2. [root@shell scripts]# vitouch2.sh 

3. #!/bin/bash

4. Path=/oldboy

5. [ -d $Path ] || mkdir $Path

6.   

7. for i in `seq 10`

8.   do

9.      char=`echo $RANDOM|md5sum|cut -c 2-11|tr[0-9] [a-j]`

10.      touch $Path/${char}_oldboy.html

11. done

12. [root@shell scripts]# shtouch2.sh   

13. [root@shell scripts]# ll -h/oldboy/

14. total 0

15. -rw-r--r-- 1 root root 0 Apr 1107:49 aeddbiacdj_oldboy.html

16. -rw-r--r-- 1 root root 0 Apr 1107:49 bccbacghba_oldboy.html

17. -rw-r--r-- 1 root root 0 Apr 1107:49 bdhijefefb_oldboy.html

18. -rw-r--r-- 1 root root 0 Apr 1107:49 bhfghjcgaa_oldboy.html

19. -rw-r--r-- 1 root root 0 Apr 1107:49 ddaacedijc_oldboy.html

20. -rw-r--r-- 1 root root 0 Apr 1107:49 ebcbbfabaf_oldboy.html

21. -rw-r--r-- 1 root root 0 Apr 1107:49 ecafccebbi_oldboy.html

22. -rw-r--r-- 1 root root 0 Apr 1107:49 egcdafafad_oldboy.html

23. -rw-r--r-- 1 root root 0 Apr 1107:49 iehfcgfaef_oldboy.html

24. -rw-r--r-- 1 root root 0 Apr 1107:49 ifddfaaicd_oldboy.html

25.   

26. 2.2批量改名

27. [root@shell scripts]# vimv2.sh    

28. #!/bin/bash

29. Path=/oldboy

30. [ -d $Path ] && cd $Path

31. for file in `ls`

32.  do

33.      mv $file `echo $file|sed -e"s#oldboy#oldgirl#g" -e "s#html#HTML#g" `

34. done

35. [root@shell scripts]# sh mv2.sh

36. [root@shell scripts]# ll -h/oldboy/

37. total 0

38. -rw-r--r-- 1 root root 0 Apr 1107:49 aeddbiacdj_oldgirl.HTML

39. -rw-r--r-- 1 root root 0 Apr 1107:49 bccbacghba_oldgirl.HTML

40. -rw-r--r-- 1 root root 0 Apr 1107:49 bdhijefefb_oldgirl.HTML

41. -rw-r--r-- 1 root root 0 Apr 1107:49 bhfghjcgaa_oldgirl.HTML

42. -rw-r--r-- 1 root root 0 Apr 1107:49 ddaacedijc_oldgirl.HTML

43. -rw-r--r-- 1 root root 0 Apr 1107:49 ebcbbfabaf_oldgirl.HTML

44. -rw-r--r-- 1 root root 0 Apr 1107:49 ecafccebbi_oldgirl.HTML

45. -rw-r--r-- 1 root root 0 Apr 1107:49 egcdafafad_oldgirl.HTML

46. -rw-r--r-- 1 root root 0 Apr 1107:49 iehfcgfaef_oldgirl.HTML

47. -rw-r--r-- 1 root root 0 Apr 1107:49 ifddfaaicd_oldgirl.HTML

48.   

49. [root@shell scripts]# vimv3.sh    

50. #!/bin/bash

51. Path=/oldboy

52. [ -d $Path ] && cd $Path

53. for file in `ls`

54.  do

55.      mv $file `echo${file/oldboy.html/oldgirl.HTML}`

56. done

57. [root@shell scripts]# sh mv3.sh

58. [root@shell scripts]# ll -h/oldboy/            

59. total 0

60. -rw-r--r-- 1 root root 0 Apr 1108:12 abcaeacdbe_oldgirl.HTML

61. -rw-r--r-- 1 root root 0 Apr 1108:12 affabgbccg_oldgirl.HTML

62. -rw-r--r-- 1 root root 0 Apr 1108:12 badbifffbg_oldgirl.HTML

63. -rw-r--r-- 1 root root 0 Apr 1108:12 ccbcifibbe_oldgirl.HTML

64. -rw-r--r-- 1 root root 0 Apr 1108:12 cchbacgegb_oldgirl.HTML

65. -rw-r--r-- 1 root root 0 Apr 1108:12 cdfbjfdiib_oldgirl.HTML

66. -rw-r--r-- 1 root root 0 Apr 1108:12 chjechdgab_oldgirl.HTML

67. -rw-r--r-- 1 root root 0 Apr 1108:12 ghibcfcbee_oldgirl.HTML

68. -rw-r--r-- 1 root root 0 Apr 1108:12 icafaafbdb_oldgirl.HTML

69. -rw-r--r-- 1 root root 0 Apr 1108:12 igiijhbebj_oldgirl.HTML

3、批量创建用户随机密码

企业面试题3：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）。

1. [root@shell scripts]# viuseradd.sh

2. #! /bin/bash

3. . /etc/init.d/functions

4.   

5. Path=/server/scripts

6. UserDb=$Path/user.db

7. FailDb=$Path/fail_user.db

8.   

9. [ -d "$Path" ] || mkdir-p $Path

10. [ -f "$UserDb" ] ||touch $UserDb

11. [ -f "$FailDb" ] ||touch $FailDb

12.   

13. for n in $(seq -w 10)

14.  do

15.     passwd=`echo $(date+%t%N)$RANDOM|md5sum|cut -c 2-9`

16.     useradd oldboy$n >&/dev/null&& user_status=$?

17.     echo "$passwd"|passwd --stdinoldboy$n >&/dev/null && pass_status=$?

18.     if [ $user_status -eq 0 -a $pass_status -eq0 ];then

19.        action "adduser oldboy$n"/bin/true

20.        echo -e "user:\toldboy$npass:$passwd" >>$UserDb

21.     else

22.        action "adduser oldboy$n"/bin/false

23.        echo -e "user:\toldboy$npass:$passwd" >>$FailDb

24.     fi

25. done

26. [root@shell scripts]# shuseradd.sh           

27. adduser oldboy01                                          [  OK  ]

28. adduser oldboy02                                          [  OK  ]

29. adduser oldboy03                                          [  OK  ]

30. adduser oldboy04                                          [  OK  ]

31. adduser oldboy05                                          [  OK  ]

32. adduser oldboy06                                          [  OK  ]

33. adduser oldboy07                                           [ OK  ]

34. adduser oldboy08                                          [  OK  ]

35. adduser oldboy09                                          [  OK  ]

36. adduser oldboy10                                          [  OK  ]

37. [root@shell scripts]# cat user.db

38. user:   oldboy01 pass:f3291720

39. user:   oldboy02 pass:457a9f30

40. user:   oldboy03 pass:ff186389

41. user:   oldboy04 pass:8f884b7c

42. user:   oldboy05 pass:26f831b4

43. user:   oldboy06 pass:344e2300

44. user:   oldboy07 pass:0736b278

45. user:   oldboy08 pass:67c1fa76

46. user:   oldboy09 pass:b11e7aa9

47. user:   oldboy10 pass:9e0c3673

 

4、判断网络主机存活

企业面试题4：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）

1. #!/bin/sh

2. for n in `seq 254`

3. do

4.   ping -c1 10.0.0.$n &>/dev/null

5.   if [ $? -eq 0 ]

6.   then

7.       echo "10.0.0.$n is up ">>/tmp/uplist.log

8.   else

9.       echo "10.0.0.$n is down ">>/tmp/downlist.log

10.   fi

11. done

5、解决DOS攻击生产案例

企业实战题5：请用至少两种方法实现！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-AINPUT -s 10.0.1.10 -j DROP。

1. [root@shell scripts] # vi dos.sh

2. #!/bin/bash

4. log= /tmp/tmp .log

6. [ -f $log ] ||  touch  $log

8. function  add_iptables(){

9.     whileread line

10.         do

11.           ip=` echo  $line| awk  '{print $2}' `

12.           count=` echo  $line| awk  '{print $1}' `

13.             if  [ $count -gt 100 ] && [`iptables -L -n| grep  "$ip" | wc  -l` -lt 1 ]

14.              then

15.                 iptables -I INPUT -s $ip -jDROP

16.                 echo  "$line isdropped"  >> /tmp/droplist .log

17.             fi

18.         done <$log

19. }

22. function  main(){

23.     whiletrue

24.            do

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

26.              netstat  -an| grep  EST| awk  -F  '[:]+'  '{print $6}' | sort | uniq  -c >$log

27.              add_iptables

28.              sleep  180

29.     done

30. }

32. main

6、MySQL启动脚本

企业实战题6：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. [root@shell scripts] # vi mysqld1.sh

2. #!/bin/bash

3. # chkconfig: 2345 65 37

4. # description: manager multiplemysqld server.

6. # Warning: This script uses the/etc/init.d/functions system function.

7. #          System  kernel version isCentOS6.6,2.6.32-504.el6.x86_64.

8. #          I'm not sure whether other systemscan be used normally.

9. # Source function library.

10. .  /etc/init .d /functions

13. Port=$2

14. datadir= /data/ $2

15. Path= "/application/mysql"

16. CmdPath= "$Path/bin"

17. MysqlCmd= "$CmdPath/mysqld_safe"

18. prog=mysqld

19. Port=$2

20. datadir= /data/ $2

21. pidfile=${PIDFILE-$datadir /mysqld .pid}

22. lockfile=${LOCKFILE- /var/lock/subsys/mysqld $Port}

23. MysqlConf= "$datadir/my.cnf"

24. RETVAL=0

26. Usage1(){

27.         echo  -e  "\033[33m USAGE: $0 {startport|stop port|status port|restart port} \033[0m"

28.         exit  6

29. }

31. Usage2(){

32.         echo  -e  "\033[33m MySQL DaemonProgram Need Configuration File,like $datadir/my.cnf \033[0m"

33.         exit  6

34. }

36. [ -n  "$Port"  -a  -z  "`echo" ${Port // [0-9]/} "`"  ] || Usage1

38. start(){

39.         [ -x $MysqlCmd ] ||  exit  5

40.         [ -f $MysqlConf ] || Usage2

41.         echo  -n $ "Starting $prog: "

42.         daemon --pidfile=${pidfile} "$MysqlCmd --defaults-file=$MysqlConf &>/dev/null &"

43.         sleep  1

44.         RETVAL=$?

45.         echo

46.         [ $RETVAL = 0 ] &&  touch ${lockfile}

47.         return  $RETVAL

48. }

50. stop(){

51.         echo  -n $ "Stopping $prog: "

52.         killproc -p $pidfile

53.         retval=$?

54.         echo

55.         [ $retval - eq  0 ] &&  rm  -f${lockfile}

56.         return  $retval

57. }

59. restart() {

60.         stop

61.         sleep  1

62.         start

63. }

65. rh_status() {

66.         status -p $pidfile

67. }

69. rh_status_q() {

70.         rh_status > /dev/null  2>&1

71. }

73. case  "$1"  in

74.     start)

75.         rh_status_q &&  exit  0

76.         $1

77.         ;;

78.     stop)

79.         rh_status_q ||  exit  0

80.         $1

81.         ;;

82.     restart)

83.         $1

84.         ;;

85.     status)

86.         rh_status

87.         ;;

88.     *)

89.         Usage1

90.         exit  2

91. esac

7、分库备份

企业实战题7:如何实现对MySQL数据库进行分库备份，请用脚本实现

1. [root@shell scripts] # vifenku_backup.sh

2. #!/bin/bash

3. MysqlUser=root

4. PassWord=oldboy123

5. Port=3306

6. Socket= "/data/$Port/mysql.sock"

7. MysqlCmd= "mysql -u$MysqlUser-p$PassWord -S $Socket"

8. Database=`$MysqlCmd -e  "showdatabases;" | egrep  - v  "Database|_schema|mysql" `

9. MysqlDump= "mysqldump-u$MysqlUser -p$PassWord -S $Socket"

10. IP=` ifconfig  eth0| awk  -F  "[:]+"  'NR==2 {print $4}' `

11. BackupDir= /backup/ $IP

13. [ -d $BackupDir ] ||  mkdir  -p$BackupDir

16. for  dbname  in  $Database

17.   do

18.      $MysqlDump --events -B $dbname| gzip >/$BackupDir/${dbname}_$( date  +%F)_bak.sql.gz

19. done

20. [root@shell 10.0.0.3] # ls

21. chongtu_2015-04-11_bak.sql.gz  oldboy_2015-04-11_bak.sql.gz  test_2015-04-11_bak.sql.gz

22. mysql_2015-04-11_bak.sql.gz    qqqqqq_2015-04-11_bak.sql.gz

8、分库分表备份

企业实战题8:如何实现对MySQL数据库进行分库加分表备份，请用脚本实现

1. [root@shell scripts] # vifenbiao_backup.sh

2. #!/bin/bash

3. MysqlUser=root

4. PassWord=oldboy123

5. Port=3306

6. Socket= "/data/$Port/mysql.sock"

7. MysqlCmd= "mysql -u$MysqlUser-p$PassWord -S $Socket"

8. Database=`$MysqlCmd -e  "showdatabases;" | egrep  - v  "Database|_schema|mysql" `

9. MysqlDump= "mysqldump-u$MysqlUser -p$PassWord -S $Socket"

10. IP=` ifconfig  eth0| awk  -F  "[:]+"  'NR==2 {print $4}' `

11. BackupDir= /backup/ $IP

13. [ -d $BackupDir ] ||  mkdir  -p$BackupDir

16. for  dbname  in  $Database

17.   do

18.      [ ! -d /$BackupDir/$dbname ] && mkdir  -p /$BackupDir/$dbname

19.      TABLE=`$MysqlCmd -e  "show tables from$dbname;" | sed  '1d' `

20.      for  table  in  $TABLE

21.         do

22.           $MysqlDump $dbname $table| gzip >/$BackupDir/$dbname/${dbname}_${table}_$( date  +%F).sql.gz

23.      done

24. done

9、打印字母数不大于6的单词

企业面试题9： 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)。

Iam oldboy teacher welcome to oldboy training class.

请用至少两种方法实现！

1. [root@shell scripts] # vi length.sh

2. #!/bin/bash

4. echo  "-------wc -L----"

5. for  word  in  I am oldboy teacherwelcome to oldboy training class.

6.   do

7.      if  [ ` echo  ${word}| wc  -L` - le  6 ]

8.      then

9.         echo  $word

10.      fi

11. done

13. echo "-----{#word}-----"

14. for  word  in  I am oldboy teacherwelcome to oldboy training class.

15.   do

16.      if  [ ${ #word} -le 6 ]

17.      then

18.         echo  $word

19.      fi

20. done

23. echo  "-----exprlength-----"

24. for  word  in  I am oldboy teacherwelcome to oldboy training class.

25.   do

26.      if  [ ` expr  length  "$word" ` - le  6]

27.      then

28.         echo  $word

29.      fi

30. done

32. echo "-----{word:0:6}-----"

33. for  word  in  I am oldboy teacherwelcome to oldboy training class.

34. do

35.     if  [  "$word"  == "${word:0:6}"  ]

36.      then

37.         echo  $word

38.     fi

39. done

41. echo  "-----awk-----"

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

44. echo  "-----awk2-----"

45. echo  -n  "I am oldboy teacherwelcome to oldboy training class."  |  awk  'BEGIN {RS=FS} length($0)<=6{print $0}'

48. echo  "-----数组-----"

49. arr=(I am oldboy teacher welcometo oldboy training class.)

50. for  word  in  ${arr[@]}

51. do

52.   if  [ ${ #word} -le 6 ]

53.   then

54.       echo  $word

55.   fi

56. done

58. echo -----------------------------

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

60. do

61.     if  [ ${ #arr[$i]} -le 6 ]

62.     then

63.        echo  ${arr[$i]}

64.     fi

65. done

66. [root@shell scripts] # shlength.sh

67. ------- wc  -L----

68. I

69. am

70. oldboy

71. to

72. oldboy

73. class.

74. -----{ #word}-----

75. I

76. am

77. oldboy

78. to

79. oldboy

80. class.

81. ----- expr  length-----

82. I

83. am

84. oldboy

85. to

86. oldboy

87. class.

88. -----{word:0:6}-----

89. I

90. am

91. oldboy

92. to

93. oldboy

94. class.

95. ----- awk -----

96. I

97. am

98. oldboy

99. to

100. oldboy

101. class

102. -----awk2-----

103. I

104. am

105. oldboy

106. to

107. oldboy

108. class.

109. -----数组-----

110. I

111. am

112. oldboy

113. to

114. oldboy

115. class.

116. -----------------------------

117. I

118. am

119. oldboy

120. to

121. oldboy

122. class.

想从0开始成为这样的SHELL高手么？请猛戳：

我要成为shell高手