Linux（17）：Shell编程（4）

案例1：批量生成随机字 符 文件名案例

使用for 循环在 /neo 目录下批量创建10个html文件，其中每个文件需要包含10个随机小写字母加固定字符串 neo创建的结果名称示例 如下：

[root@oldgirl C19]# ls /neo
apquvdpqbk_neo.html mpyogpsmwj_neo.html txynzwofgg_neo.html
bmqiwhfpgv_neo.html mtrzobsprf_neo.html vjxmlflawa_neo.html
jhjdcjnjxc_neo.html qeztkkmewn_neo.html
jpvirsnjld_neo.html ruscyxwxai_neo.html

参考如下：

# 生成随机数的方式：
echo $RANDOM                          # 随机数的范围： 0~32767
openssl rand -base64 10                # 10 表示要生成的随机数的长度
date +%s%N                            # 用时间做随机数
head /dev/urandom |cksum
uuidgen                                # 利用uuid
cat /proc/sys/kernel/random/uuid
mkpasswd                             # 需要先安装 expect ； yum install expect -y
    l 总长度
    d 数字个数
    c 小写字母个数
    C 大写字母个数
    s 特殊字符个数

# 示例：
[root@m01 ~]# mkpasswd -l 20 -d 17 -C 1 -c 1 -s 1
1194S1242h756%909877

# 获取到随机10个小写字母
[root@m01 ~]# echo "OLDBOY$RANDOM"
OLDBOY31600
[root@m01 ~]# echo "OLDBOY$RANDOM"|md5sum
2b33f154112a2f371beba1600d24f246  -
[root@m01 ~]# echo "OLDBOY$RANDOM"|md5sum|tr 0-9 a-j
icfafgebagjaajeieifeifabgfhfeegj  -
[root@m01 ~]# echo "OLDBOY$RANDOM"|md5sum|tr 0-9 a-j |cut -c 2-11
afbagebbdf            # 获取到随机10个小写字母
[root@m01 ~]# 

[root@m01 ~]# mkpasswd -l 10 -d 0 -C 0 -c 10 -s 0        # 获取到随机10个小写字母
tkbviqfovu
[root@m01 ~]#

echo "OLDBOY$RANDOM"|md5sum|tr 0-9 a-j |cut -c 2-11
    echo "" | md5sum                    # 查看一个字符串的md5值
    cat file | tr [0-9] [a-j]                 # 把文件中的数字0-9替换为a-j
    cut -c 2-11                                # -c参数表示 仅显示行中指定范围的字符

# 示例代码：
[root@m01 cases]# cat case01.sh
#!/bin/bash
##############################################################
# File Name: case01.sh
# Version: V1.0
# Author: neo
# Organization: anonymous
# Created Time : 2019-07-04 11:15:30
# Description:
##############################################################
path=/neo
[ -d $path ] || mkdir -p $path      # 如果 /neo 目录不存在则创建

for n in {1..10}
do
    random=`mkpasswd -l 10 -d 0 -C 0 -c 10 -s 0`
    touch $path/${random}_neo.html
done
[root@m01 cases]# sh case01.sh
[root@m01 neo]# ll
total 0
-rw-r--r-- 1 root root 0 Jul  4 11:23 hqxdsueipv_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 jpiauceiiy_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 lagtetdxnu_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 ogkstnleki_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 qkljrkpckc_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 rpslndkrjc_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 snvcqbwlko_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 tuwsslvcgn_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 tzxismkjka_neo.html
-rw-r--r-- 1 root root 0 Jul  4 11:23 wlaroblbvi_neo.html
[root@m01 neo]# 

案例2：批量改名特殊案例

将以上案例1中结果文件名中的 neo 字符串全部改成 Neomaple，最好用 for 循环实现并且将扩展名html全部改成大写

参考如下：

# 方式一：for 循环
[root@m01 cases]# cat case02.sh
#!/bin/bash
for file in `ls /neo/*.html`
do
    mv $file /${file/neo.html/Neomaple.HTML}
done
[root@m01 cases]# 

# 方式二：awk
[root@m01 neo]# ls *.html|awk -F "neo.html" '{print "mv",$0,$1"Neomaple.HTML"}'
mv dbizjjvosl_neo.html dbizjjvosl_Neomaple.HTML
mv ezoiojifzy_neo.html ezoiojifzy_Neomaple.HTML
mv fanspikyqs_neo.html fanspikyqs_Neomaple.HTML
mv hmvkxpoyru_neo.html hmvkxpoyru_Neomaple.HTML
mv hymssbshwu_neo.html hymssbshwu_Neomaple.HTML
mv kgavlirhts_neo.html kgavlirhts_Neomaple.HTML
mv khxcbyrnnt_neo.html khxcbyrnnt_Neomaple.HTML
mv ntgtztpzsp_neo.html ntgtztpzsp_Neomaple.HTML
mv pfykhbwgyk_neo.html pfykhbwgyk_Neomaple.HTML
mv sybwbmnmyh_neo.html sybwbmnmyh_Neomaple.HTML
[root@m01 neo]# ls *.html|awk -F "neo.html" '{print "mv",$0,$1"Neomaple.HTML"}'|bash

# 方式三：rename
[root@m01 neo]# rename "neo.html" "Neomaple.HTML" *.html    # 把 neo.html 改成 Neomaple.HTML ；*.html 表示针对 以 html结尾的文件

案例3：批量创建特殊要求用户案例

批量创建10个系统帐号 neo01 - neo10 并设置密码（密码为随机数 ，要求字符和数字等混合）

# 分析：
1） 生成01~10的序列：
        echo {01..10}
        seq -w 10
2） 随机数：
        openssl rand -base64 10
3） 创建用户和密码：
        useradd neo01                    # 创建用户
        # 设置密码方法1：
        echo 密码 |passwd --stdin 用户名
        # 设置密码方法2：
        chpasswd 命令
            chpasswd 设置密码时，用户名和密码要遵守这种格式： 用户名:密码
4） for 循环

# 方式一：
[root@m01 cases]# cat case03.sh
#!/bin/bash
for n in {01..10}
do
    passwd=`openssl rand -base64 10`    # 要把随机密码保存到变量中
    useradd neo$n
    echo $passwd|passwd --stdin neo$n
    echo -e "neo$n\t$passwd" >>/tmp/user.list   # 把密码保存到文件中； echo -e 的作用是 解析 \t
done
[root@m01 cases]# sh case03.sh
Changing password for user neo01.
passwd: all authentication tokens updated successfully.
Changing password for user neo02.
passwd: all authentication tokens updated successfully.
Changing password for user neo03.
passwd: all authentication tokens updated successfully.
Changing password for user neo04.
passwd: all authentication tokens updated successfully.
Changing password for user neo05.
passwd: all authentication tokens updated successfully.
Changing password for user neo06.
passwd: all authentication tokens updated successfully.
Changing password for user neo07.
passwd: all authentication tokens updated successfully.
Changing password for user neo08.
passwd: all authentication tokens updated successfully.
Changing password for user neo09.
passwd: all authentication tokens updated successfully.
Changing password for user neo10.
passwd: all authentication tokens updated successfully.
[root@m01 cases]# cat /tmp/user.list
neo01    pFvlvG0NXpIvYg==
neo02    UPRO/U7uTxnJNw==
neo03    0xkAtO5U70ws5w==
neo04    wXR+K7fl+8i5wA==
neo05    7bt6b09wv5dw7Q==
neo06    AUNPXdRaJ8NUTA==
neo07    E+JPwENB7KXHUA==
neo08    1lZylckuf8rNlg==
neo09    ZD7qVwMfsPMvzg==
neo10    B3EgYyb/swvDow==
[root@m01 cases]# su - neo01
[neo01@m01 ~]$ su - neo02
Password:
[neo02@m01 ~]$ whoami
neo02
[neo02@m01 ~]$ 

# 方式二：
[root@m01 cases]# cat case0302.sh
#!/bin/bash
for n in `seq -w 11 15`
do
    passwd=`openssl rand -base64 10`    # 要把随机密码保存到变量中
    useradd neo$n
    echo "neo$n:$passwd" >>/tmp/chpasswd.log    # 把用户名和密码以 用户名:密码 这种格式保存到 一个文件 chpasswd.log 中
done

chpasswd </tmp/chpasswd.log     # 把 /tmp/chpasswd.log 这个文件通过输出重定向 给 chpasswd 命令处理，由于 chpasswd.log 中是以 用户名:密码 格式保存的，所以 chpasswd 命令能直接处理
[root@m01 cases]# sh case0302.sh
[root@m01 cases]# cat /tmp/chpasswd.log
neo11:Ij76k7pbfyByZQ==
neo12:lmCPKpKoUP/UOg==
neo13:JNIfuo8wwXgEkA==
neo14:QkBxlLf6mhQP+g==
neo15:fbvtdTSu9yTySg==
[root@m01 cases]# su - neo11
[neo11@m01 ~]$ su - neo15
Password:
[neo15@m01 ~]$ 

# 方式三：
[root@m01 cases]# cat case0303.sh
#!/bin/bash
. /etc/init.d/functions

if [ $UID -ne 0 ]
then
    action "only root can execute this script" /bin/false
    exit 1
fi

for n in {12..17}
do
    passwd=`openssl rand -base64 10`
    if `! grep -w  "neo$n" /etc/passwd &>/dev/null`   # grep -w 表示精确匹配；grep 如果获取到相应结果，则grep命令的执行结果为0（真），反之则执行结果为1（假）；if `命令表达式 &>/dev/null` 时是判断 命令表达式的执行结果是否为真（由于只看执行结果，此时加 &>/dev/null,否则 if 字符串 会报错）
    then
        # \ 表示换行符
        useradd neo$n &>/dev/null && \
        echo $passwd|passwd --stdin neo$n &>/dev/null && \
        echo -e "neo$n\t$passwd" >>/tmp/user.list && \
        action "neo$n added successfully" /bin/true
    else
        action "neo$n exists already" /bin/false
    fi
done
[root@m01 cases]# sh case0303.sh
neo12 exists already                                       [FAILED]
neo13 exists already                                       [FAILED]
neo14 exists already                                       [FAILED]
neo15 exists already                                       [FAILED]
neo16 added successfully                                   [  OK  ]
neo17 added successfully                                   [  OK  ]
[root@m01 cases]# 

案例4： 扫描网络内存活主机案例

写一个Shell脚本，判断 10.0.0.0/24 网络里，当前在线的IP有哪些

1） ping 命令
[root@m01 ~]# ping -c 2 -i 1 -w 3 10.0.0.61
PING 10.0.0.61 (10.0.0.61) 56(84) bytes of data.
64 bytes from 10.0.0.61: icmp_seq=1 ttl=64 time=0.079 ms
64 bytes from 10.0.0.61: icmp_seq=2 ttl=64 time=0.052 ms

--- 10.0.0.61 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1005ms
rtt min/avg/max/mdev = 0.052/0.065/0.079/0.015 ms

ping 命令：
    -c   ping 的次数
    -i   ping 时间间隔（s）
    -w   ping 的总共的时长（s）

2） nmap命令
nmap -sP 10.0.0.0/24

# 方式一： ping
[root@m01 cases]# cat case0401.sh
#!/bin/bash
##############################################################
# File Name: case0401.sh
# Version: V1.0
# Author: neo
# Organization: anonymous
# Created Time : 2019-07-05 00:54:20
# Description:
##############################################################
for n in {1..254}
do
    {
    if `ping -c 1 -w 3 10.0.0.$n &>/dev/null`   # ping 通为true
    then
        echo "10.0.0.$n is up"
    else
        echo "10.0.0.$n is down"
    fi
    } &  # {} & 表示 {} 里面的代码并发执行；此处表示批量 ping
done
[root@m01 cases]# 

# 方式二： nmap
[root@m01 ~]# nmap -sP 10.0.0.0/24

Starting Nmap 5.51 ( http://nmap.org ) at 2019-07-05 01:34 CST
Nmap scan report for 10.0.0.61
Host is up.
Nmap scan report for 10.0.0.253
Host is up (0.0032s latency).
MAC Address: 00:50:56:C0:00:08 (VMware)
Nmap scan report for 10.0.0.254
Host is up (0.00081s latency).
MAC Address: 00:50:56:EA:79:FB (VMware)
Nmap done: 256 IP addresses (3 hosts up) scanned in 8.36 seconds
[root@m01 ~]# nmap -sP 10.0.0.0/24|awk '/Nmap scan report for/{print $NF}'      # $NF 表示的最后一个Field（列），即输出最后一个字段的内容
10.0.0.61
10.0.0.253
10.0.0.254
[root@m01 ~]# 

案例5：数据库的备份

# 案例5.1：MySQL 数据库分库备份
# 常规方法：
mysqldump -B oldboy oldgirl test|gzip >bak.sql.gz        # --databases, -B： 用于备份多个数据库，如果没有该选项，mysqldump把第一个名字参数作为数据库名，后面的作为表名。使用该选项，mysqldum把每个名字都当作为数据库名。

# 分库备份：
mysqldump -B oldboy |gzip >bak.sql.gz
mysqldump -B oldgirl |gzip >bak.sql.gz
mysqldump -B test|gzip >bak.sql.gz

# 相关命令：
mysqldump -uroot -p123456 db_name table1 table2 |gzip >bak.sql.gz  # mysqldump 命令中只有第一个参数 db_name 是库名，后面跟的所有参数都是表名

# 命令操作如下：
[root@db01 application]# /application/mysql/bin/mysql -uroot -p123456 -e "show databases;"        # 命令行获取数据库名
Warning: Using a password on the command line interface can be insecure.
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
| wordpress          |
+--------------------+
[root@web01 ~]# /application/mysql/bin/mysql -uroot -p123456 -e "show databases;"|grep -v _schema    # 去掉包含 _schema 的数据库
Warning: Using a password on the command line interface can be insecure.
Database
mysql
test
wordpress
[root@web01 ~]# /application/mysql/bin/mysql -uroot -p123456 -e "show databases;"|grep -v _schema|sed 1d    # 去掉第一行的 Database
Warning: Using a password on the command line interface can be insecure.
mysql
test
wordpress
[root@web01 ~]# /application/mysql/bin/mysql -uroot -p123456 -e "show databases;" 2>/dev/null|grep -v _schema|sed 1d    # 2>/dev/null 表示错误信息不输出
mysql
test
wordpress
[root@web01 ~]# 

# 示例代码如下：
[root@web01 cases]# cat backup-db.sh
#/bin/bash
path=/backup

[ -d $path ] || mkdir -p $path

for dbname in `/application/mysql/bin/mysql -uroot -p123456 -e "show databases;" 2>/dev/null |grep -v _schema|sed 1d`
do
    /application/mysql/bin/mysqldump -uroot -p123456 -B $dbname|gzip  >$path/${dbname}_$(date +%F).sql.gz 2>/dev/null
done
[root@web01 cases]# sh backup-db.sh
Warning: Using a password on the command line interface can be insecure.
Warning: Using a password on the command line interface can be insecure.
Warning: Using a password on the command line interface can be insecure.
[root@web01 cases]# 

[root@web01 backup]# ll
total 372
-rw-r--r-- 1 root root 179858 Jul  6 00:48 mysql_2019-07-06.sql.gz
-rw-r--r-- 1 root root    517 Jul  6 00:48 test_2019-07-06.sql.gz
-rw-r--r-- 1 root root 193084 Jul  6 00:48 wordpress_2019-07-06.sql.gz
[root@web01 backup]# 

# 案例5.2：MySQL 数据库分库分表备份
# 相关命令：
mysqldump oldboy test test1|gzip >bak.sql.gz
    # 1、 oldboy 库名
    # 2、 test、test1 都是表名

[root@db01 ~]# /application/mysql/bin/mysql -uroot -p123456 -e "show tables from wordpress;"    # 命令行获取某个数据库下的表名
Warning: Using a password on the command line interface can be insecure.
+-----------------------+
| Tables_in_wordpress   |
+-----------------------+
| wp_commentmeta        |
| wp_comments           |
| wp_links              |
| wp_options            |
| wp_postmeta           |
| wp_posts              |
| wp_term_relationships |
| wp_term_taxonomy      |
| wp_termmeta           |
| wp_terms              |
| wp_usermeta           |
| wp_users              |
+-----------------------+
[root@web01 ~]# /application/mysql/bin/mysql -uroot -p123456 -e "show tables from wordpress;"|sed 1d
Warning: Using a password on the command line interface can be insecure.
wp_commentmeta
wp_comments
wp_links
wp_options
wp_postmeta
wp_posts
wp_term_relationships
wp_term_taxonomy
wp_termmeta
wp_terms
wp_usermeta
wp_users
[root@db01 ~]# 

# 示例代码如下：
[root@web01 cases]# cat backup-db-tb.sh
#/bin/bash
path=/backup

[ -d $path ] || mkdir -p $path
mysql="/application/mysql/bin/mysql -uroot -p123456"
mysqldump="/application/mysql/bin/mysqldump -uroot -p123456"

for dbname in `$mysql -e "show databases;" 2>/dev/null |grep -v _schema|sed 1d`    # 先获取数据库的名字
do
    for tname in `$mysql -e "show tables from $dbname;" 2>/dev/null |sed 1d`       # 再获取表名
    do
    if [ $dbname = "mysql" ]
    then
        $mysqldump --skip-lock-tables $dbname $tname|gzip  >$path/${dbname}-${tname}_$(date +%F).sql.gz 2>/dev/null  # 跳过 mysql 这个数据库 中的锁表
    else
            $mysqldump  $dbname $tname|gzip  >$path/${dbname}-${tname}_$(date +%F).sql.gz 2>/dev/null
    fi
    done
done
[root@web01 cases]# 

案例6：ssh免密密钥批量分发文件脚本

有3台机器，61、7 和 8，采用ssh免密密钥实现从61主机到其它两台机器无密码登陆后，写脚本实现从61主机批量分发任意文件到另外两台机器上任意目录下

# 先生成、分发密钥：
[root@m01 ~]# ssh-keygen -t dsa                    # 生成密钥
Generating public/private dsa key pair.
Enter file in which to save the key (/root/.ssh/id_dsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_dsa.
Your public key has been saved in /root/.ssh/id_dsa.pub.
The key fingerprint is:
91:05:b6:09:9a:eb:cd:18:3f:b6:cf:b9:dd:ec:ef:fd root@m01
The key's randomart image is:
+--[ DSA 1024]----+
|      . o..      |
|     o o =       |
|    o   =        |
|     .   .       |
|    o   S        |
|   . *           |
|    o *          |
|     . + o o   . |
|      ..=...+oo E|
+-----------------+
[root@m01 ~]# ll ~/.ssh/
total 8
-rw------- 1 root root 668 Jul  6 10:53 id_dsa
-rw-r--r-- 1 root root 598 Jul  6 10:53 id_dsa.pub
-rw-r--r-- 1 root root   0 Jul  6 10:13 known_hosts
[root@m01 ~]# ll ~/.ssh/
total 8
-rw------- 1 root root 668 Jul  6 10:53 id_dsa
-rw-r--r-- 1 root root 598 Jul  6 10:53 id_dsa.pub
-rw-r--r-- 1 root root   0 Jul  6 10:13 known_hosts
[root@m01 ~]# for n in 7 8;do ssh-copy-id -i /root/.ssh/id_dsa.pub 172.16.1.$n;done        # 分发公钥： ssh-copy-id -i /root/.ssh/id_dsa.pub 172.16.1.7
The authenticity of host '172.16.1.7 (172.16.1.7)' can't be established.
RSA key fingerprint is 22:07:4d:36:3c:5e:eb:46:80:a2:ef:40:45:8c:93:46.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.16.1.7' (RSA) to the list of known hosts.
root@172.16.1.7's password:
Now try logging into the machine, with "ssh '172.16.1.7'", and check in:

  .ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

The authenticity of host '172.16.1.8 (172.16.1.8)' can't be established.
RSA key fingerprint is 22:07:4d:36:3c:5e:eb:46:80:a2:ef:40:45:8c:93:46.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.16.1.8' (RSA) to the list of known hosts.
root@172.16.1.8's password:
Now try logging into the machine, with "ssh '172.16.1.8'", and check in:

  .ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

[root@m01 ~]# for n in 7 8;do echo 172.16.1.$n && ll ~/.ssh/ ;done
172.16.1.7
total 12
-rw------- 1 root root 668 Jul  6 10:53 id_dsa
-rw-r--r-- 1 root root 598 Jul  6 10:53 id_dsa.pub
-rw-r--r-- 1 root root 784 Jul  6 11:00 known_hosts
172.16.1.8
total 12
-rw------- 1 root root 668 Jul  6 10:53 id_dsa
-rw-r--r-- 1 root root 598 Jul  6 10:53 id_dsa.pub
-rw-r--r-- 1 root root 784 Jul  6 11:00 known_hosts
[root@m01 ~]#

# 示例代码如下：
[root@m01 cases]# cat case06-distribute-file.sh
#!/bin/bash
##############################################################
# File Name: case06-distribute-file.sh
# Version: V1.0
# Author: neo
# Organization: anonymous
# Created Time : 2019-07-06 11:09:01
# Description:
##############################################################
. /etc/init.d/functions

if [ $# -ne 2 ]
then
    echo "Usage:$0 localdir remotedir"
    exit 1
fi

for n in 7 8 9
do
    scp -rp $1 172.16.1.$n:$2 &>/dev/null
    if [ $? -eq 0 ]
    then
        action "distribute 172.16.1.$n successfully" /bin/true
    else
        action "distribute 172.16.1.$n failed" /bin/false
    fi
done
[root@m01 cases]# sh case06-distribute-file.sh
Usage:case06-distribute-file.sh localdir remotedir
[root@m01 cases]# sh case06-distribute-file.sh /neo /neozheng/
distribute 172.16.1.7 successfully                         [  OK  ]
distribute 172.16.1.8 successfully                         [  OK  ]
distribute 172.16.1.9 failed                               [FAILED]            #  失败原因是 9主机没开
[root@m01 cases]# 

案例7：破解 RANDOM 随机数案例

已知下面的字符串是通过 RANDOM 随机数变量 md5sum 后，再截取一部分连续字符串的结果，请破解这些字符串对应的使用 md5sum 处理前的 RANDOM 对应的数字
21029299
00205d1c
a3da1677
1f6d12dd
890684b

# 分析：
1） RANDOM随机数的范围 0~32767，就需要把 0~32767 都用 md5sum 加密  >md5.log
2） 比较：grep "1f6d12dd" md5.log |wc -l

[root@m01 ~]# array=(
> 21029299
> 00205d1c
> a3da1677
> 1f6d12dd
> 890684b
> )
[root@m01 ~]# echo ${array[*]}
21029299 00205d1c a3da1677 1f6d12dd 890684b
[root@m01 ~]# echo ${array[*]}|tr " " "|"
21029299|00205d1c|a3da1677|1f6d12dd|890684b        # 把 数组中的元素以 “或”符号 | 分隔
[root@m01 ~]#

# 示例代码如下：
[root@m01 cases]# cat case07-decode-random.sh
#!/bin/bash
##############################################################
# File Name: case07-decode-random.sh
# Version: V1.0
# Author: neo
# Organization: anonymous
# Created Time : 2019-07-06 12:54:04
# Description:
##############################################################
array=(
21029299
00205d1c
a3da1677
1f6d12dd
890684b
)

function Funcmd5(){
    for n in {1..32767}
    do
        echo -e "$n\t`echo $n|md5sum`" >>/tmp/md5.log &
    done
}

function FuncJudge(){
    char=`echo ${array[*]}|tr " " "|"`
    egrep $char /tmp/md5.log
}

function main(){
    Funcmd5
    FuncJudge
}
main
[root@m01 cases]# sh case07-decode-random.sh
1346    00205d1cbbeb97738ad5bbdde2a6793d  -
7041    1f6d12dd61b5c7523f038a7b966413d9  -
10082    890684ba3685395c782547daf296935f  -
25345    a3da1677501d9e4700ed867c5f33538a  -
25667    2102929901ee1aa769d0f479d7d78b05  -
[root@m01 cases]# 

案例8：批量检查多个网站地址是否正常

批量检查多个网站地址是否正常
要求：
1、使用 shell 数组方法实现，检测策略尽量模拟用户访问 。
2、每 10 秒钟做一次所有的检测，无法访问的输出报警。
3、待检测的地址如下
http://blog.oldboyedu.com
http://blog.etiantian.org
http://oldboy.blog.51cto.com
http://10.0.0.7

# 示例代码如下：
[root@m01 cases]# cat case08-checkurl.sh
#!/bin/bash
##############################################################
# File Name: case08-checkurl.sh
# Version: V1.0
# Author: neo
# Organization: anonymous
# Created Time : 2019-07-06 19:03:48
# Description:
##############################################################
. /etc/init.d/functions

array=(
http://blog.oldboyedu.com
http://blog.etiantian.org
http://oldboy.blog.51cto.com
http://10.0.0.7
)

function CheckUrl(){
    wget -t 2 -T 5 -o /dev/null -q $1
    if [ $? -eq 0 ]
    then
        action "$1 is up" /bin/true
    else
        action "$1 is down" /bin/false
    fi
}

function HandleCheck(){
    for url in ${array[*]}
    do
        CheckUrl $url
    done
}

function main(){
    while true
    do
        HandleCheck
        sleep 10
    done
}
main
[root@m01 cases]# sh case08-checkurl.sh
http://blog.oldboyedu.com is up                            [  OK  ]
http://blog.etiantian.org is down                          [FAILED]
http://oldboy.blog.51cto.com is up                         [  OK  ]
http://10.0.0.7 is down                                    [FAILED]
...
[root@m01 cases]# 

案例10：开发MySQL服务启动停止脚本

要求：用函数、case语句和if语句等实现

# 解答：
    /etc/init.d/mysqld {start|stop|restart}

# 分析：
    1. 启动：
        /bin/bash mysqld_safe --user=mysql &

    2. 停止：
        mysqladmin -u用户名 -p密码 shutdown
        killall
        pkill
        kill pid （推荐）

# 示例代码如下：
[root@web01 cases]# cat mysqld.sh
#!/bin/bash
# chkconfig: 2345 20 80
# description: mysql start and stop script
##############################################################
# File Name: mysqld.sh
# Version: V1.0
# Author: neo
# Organization: anonymous
# Created Time : 2019-07-07 13:44:57
# Description:
##############################################################
lockfile=/var/lock/subsys/mysqld                                         # 先定义一个锁文件
mysqld_pid_file_path="/application/mysql/data/${HOSTNAME}.pid"          # 定义 mysql 进程号的路径

. /etc/init.d/functions     

function start(){
    /bin/sh /application/mysql/bin/mysqld_safe --user=mysql &>/dev/null &
    retval=$?
    if [ $retval -eq 0 ]
    then
        action "mysql startup ok" /bin/true
        touch $lockfile                        # 启动成功后，就创建一个锁文件
        return $retval
    else
        action "mysql startup failed" /bin/false
        return $retval
    fi
}

function stop(){
    if test -s $mysqld_pid_file_path                    # -s ---> 判断文件是否存在且不为空
    then
        mysqld_pid=`cat $mysqld_pid_file_path`
        if (kill -0 $mysqld_pid &>/dev/null)      # kill -0 进程号  ---> 判断该进程号对应的服务是否存在；存在则echo $?返回0，不存在返1
        then
            kill $mysqld_pid
            retval=$?
            if [ $retval -eq 0 ]
            then
                action "mysql stop ok" /bin/true
                \rm -f $lockfile           # 停止成功后就删除锁文件
                return $retval
            else
                action "mysql stop failed" /bin/false
                return $retval
            fi

        else        # 此种情况是：$mysqld_pid 对应的 mysqld 服务不存在
            action "mysqld service is not running"
            return 2
        fi

    else    # 此种情况是： $mysqld_pid_file_path 对应的路径不存在
        action "$mysqld_pid_file_path not exist, or mysqld not startup" /bin/false
        return 3
    fi
}

case "$1" in
    start)
        start
        retval=$?               # 接收 start 的执行结果并赋值给 retval 作为返回值
        ;;
    stop)
        stop
        retval=$?
        ;;
    restart)
        stop && sleep 1 && start
        retval=$?
        ;;
    *)
        echo "Usage:$0 {start|stop|restart}"
        exit 1
esac
exit $retval                    # 把上面的执行结果返回给脚本外面
[root@web01 cases]#

# mysqld.sh 脚本测试
[root@web01 cases]# sh mysqld.sh
Usage:mysqld.sh {start|stop|restart}
[root@web01 cases]# sh mysqld.sh start
mysql startup ok                                           [  OK  ]
[root@web01 cases]# lsof -i:3306
COMMAND  PID  USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
mysqld  4084 mysql   16u  IPv6  19781      0t0  TCP *:mysql (LISTEN)
[root@web01 cases]# sh mysqld.sh restart
mysql stop ok                                              [  OK  ]
mysql startup ok                                           [  OK  ]
[root@web01 cases]# lsof -i:3306
COMMAND  PID  USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
mysqld  4224 mysql   16u  IPv6  20084      0t0  TCP *:mysql (LISTEN)
[root@web01 cases]# sh mysqld.sh stop
mysql stop ok                                              [  OK  ]
[root@web01 cases]# lsof -i:3306
[root@web01 cases]# 

# 给自写的 mysqld.sh 脚本 加执行权限
[root@web01 cases]# cp mysqld.sh /etc/init.d/mysqld_neo
[root@web01 cases]# ll /etc/init.d/mysqld_neo
-rw-r--r-- 1 root root 2521 Jul  7 14:29 /etc/init.d/mysqld_neo
[root@web01 cases]# chmod +x /etc/init.d/mysqld_neo
[root@web01 cases]# ll /etc/init.d/mysqld_neo
-rwxr-xr-x 1 root root 2521 Jul  7 14:29 /etc/init.d/mysqld_neo
[root@web01 cases]# 

案例11：单词及字母去重排序案例

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 to assist users design,implement and support squid installations. Please browse the documentation and support sections for more infomation, by oldboy training.

# 按单词出现频率降序排序：
# 方法一：
[root@m01 ~]# a="the squid project provides a number of resources to assist users design,implement and support squid installations. Please browse the documentation and support sections for more infomation, by oldboy training."
[root@m01 ~]# echo $a|tr " ,." "\n"|awk '!/^$/{h[$1]++}END{for(word in h) print h[word],word}'|sort -rn
2 the
2 support
2 squid
2 and
1 users
1 training
1 to
1 sections
1 resources
1 provides
1 project
1 Please
1 oldboy
1 of
1 number
1 more
1 installations
1 infomation
1 implement
1 for
1 documentation
1 design
1 by
1 browse
1 assist
1 a
[root@m01 ~]# 

# 方法二：
[root@m01 ~]# sentence="the squid project provides a number of resources to assist users design,implement and support squid installations. Please browse the documentation and support sections for more infomation, by oldboy training."
[root@m01 ~]# echo $sentence |awk -F "[ ,.]+" '{for(i=1;i<=NF;i++)array[$i]++}END{for(key in array)print array[key],key}'|sort -rn
2 the
2 support
2 squid
2 and
1 users
1 training
1 to
1 sections
1 resources
1 provides
1 project
1 Please
1 oldboy
1 of
1 number
1 more
1 installations
1 infomation
1 implement
1 for
1 documentation
1 design
1 by
1 browse
1 assist
1 a
1
[root@m01 ~]#

# 注意： awk 能以 空 作为 分隔符

# 按字母出现频率降序排序：
# 方法一：
[root@m01 ~]# sentence="the squid project provides a number of resources to assist users design,implement and support squid installations. Please browse the documentation and support sections for more infomation, by oldboy training."
[root@m01 ~]# echo $sentence |grep -o "[^ ,.]"|awk '{h[$1]++}END{for(char in h) print h[char],char}'|sort -rn
19 s
18 o
17 e
15 t
14 n
14 i
12 r
10 a
8 u
8 d
7 p
6 m
5 l
4 c
4 b
3 f
2 y
2 q
2 h
2 g
1 w
1 v
1 P
1 j
[root@m01 ~]# 

# grep -o 表示 只输出匹配的内容：
    grep -o "[^ ,\.]"  --->  [^] 表示 只输出匹配的选项，所以 该命令的意思是： 排除 空格 逗号 和 点

# 方法二：
# 注意： awk 可以用空作为分隔符
[root@m01 ~]# echo $sentence|sed 's#[ ,.]##g'        # 利用 sed 把 空格 逗号 和 点 替换为 空
thesquidprojectprovidesanumberofresourcestoassistusersdesignimplementandsupportsquidinstallationsPleasebrowsethedocumentationandsupportsectionsformoreinfomationbyoldboytraining
[root@m01 ~]# echo $sentence |sed "s#[ ,.]##g"|awk -F "" '{for(i=1;i<=NF;i++)array[$i]++}END{for(key in array)print array[key],key}'
8 u
2 h
1 v
14 i
1 w
1 P
1 j
2 y
5 l
6 m
14 n
10 a
4 b
18 o
4 c
7 p
8 d
2 q
12 r
17 e
3 f
19 s
2 g
15 t
[root@m01 ~]# 

# awk -F ""  ---> 表示 以空作为分隔符
# {for(i=1;i<=NF;i++)array[$i]++}  ---> 把 echo $sentence |sed "s#[ ,.]##g" 得到的那个字符串进行 横向处理，即把每个字母作为一列；横向处理字符串从来得到一个数组 array；i 表示第i列

# 最终命令：
[root@m01 ~]# echo $sentence |sed "s#[ ,.]##g"|awk -F "" '{for(i=1;i<=NF;i++)array[$i]++}END{for(key in array)print array[key],key}'|sort -rn
19 s
18 o
17 e
15 t
14 n
14 i
12 r
10 a
8 u
8 d
7 p
6 m
5 l
4 c
4 b
3 f
2 y
2 q
2 h
2 g
1 w
1 v
1 P
1 j
[root@m01 ~]#