小脚本与expect的应用

企业开发 2020-08-10 18:11:24 阅读次数: 0

编写脚本，接收两个位置参数，magedu和/www，判断系统是否有magedu，如果没有则自动创建magedu用户，并自动设置家目录为/www

[root@Centos7 scripts]# cat create_user.sh
#!/bin/bash
#

[ "$#" -eq 2 ]  || { echo "Please enter two parameters: magedu /www" ; exit 1 ;}

if [ "$1" == "magedu" -a "$2" == "/www" ] || [ "$1" == "/www" -a "$2" == "magedu" ]; then
    for i in $* ; do
        if [ "$i" == "magedu" ]; then
            USERNAME=$i
        else
            USERHOME=$i
        fi
    done
else
    echo "Parameter must be magedu and /www ..."
    exit 1
fi
if id ${USERNAME} &> /dev/null; then
    echo "${USERNAME} is existed..."
else
    useradd -d ${USERHOME} ${USERNAME}
    echo "${USERNAME} is created..."
fi

测试：

[root@Centos7 scripts]# ./create_user.sh 
Please enter two parameters: magedu /www

[root@Centos7 scripts]# ./create_user.sh www magedu
Parameter must be magedu and /www ...

[root@Centos7 scripts]# ./create_user.sh www magedu www
Please enter two parameters: magedu /www

[root@Centos7 scripts]# ./create_user.sh /www magedu 
magedu is created...
[root@Centos7 scripts]# ./create_user.sh /www magedu 
magedu is existed...
[root@Centos7 scripts]# getent passwd magedu
magedu:x:1001:1001::/www:/bin/bash

[root@Centos7 scripts]# ll /www -d
drwx------ 3 magedu magedu 78 8月  10 11:27 /www

expect
expect是由Don Libes基于Tcl（Tool Command Language）语言开发的，主要应用于自动化交互式操作的场景，借助expect处理交互式的命令，可以将交互过程如：ssh登陆，ftp登陆等写在一个脚本上，使之自动化完成。尤其适用于需要对多台服务器执行相同操作的环境，可以大大提高系统管理人员的工作效率

示例：ssh连接192.168.2.121
先观察当前主机ssh连接121有什么特征

[root@centos7 scripts]# ssh 192.168.2.121
[email protected]'s password:            #在ssh连接121时，需要输入密码，关键字是passwd

使用脚本实现自动登录并且还停留在121上
注意：
1、脚本后缀名.exp （约定俗成的，并非一定）
2、脚本开头是/usr/bin/expect (通过which expect查看路径)

[root@centos7 scripts]# which expect
/usr/bin/expect
[root@centos7 scripts]# vim expect_ssh.exp
[root@centos7 scripts]# cat expect_ssh.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"

spawn ssh $username@$host
expect "password" {send "$password\r"}     #\r是回车
#interact                                  #当注释interact时，是不会停留在121机器上的  

[root@centos7 scripts]# chmod +x expect_ssh.exp
[root@centos7 scripts]# ./expect_ssh.exp
spawn ssh [email protected]
[email protected]'s password: [root@centos7 scripts]#        #直接返回到了测试机器终端上

[root@centos7 scripts]# vim expect_ssh.exp
[root@centos7 scripts]# cat expect_ssh.exp
#!/usr/bin/expect
#
set timeout 30                    #设置超时时长，单位为秒，默认是10秒
set host "192.168.2.121"          #设置变量host
set username "root"               #设置变量username
set password "123.com"            #设置变量password

spawn ssh $username@$host         #spawn是进入expect环境后才才可以执行expect内部命令，如果没有装expect或直接在默认的shell下执行是找不到spawn命令的，主要功能就是给ssh运行进程加个壳，用来传递交互指令
expect "password" {send "$password\r"}
interact                          #开启interact，对比下效果；执行完成后保持交互状态，把控制权交给控制台，这个时候就可以手工操作了。如果没有这一句登录完成后会退出，而不是留在远程终端上

[root@centos7 scripts]# ./expect_ssh.exp
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Jun 21 13:48:37 2020 from centos7.lan
[root@Centos6 ~]#                 #这台centos6的机器就是192.168.2.121

这就是对上述这段简单简单脚本的分析，在上述的示例中，涉及到expect中一个非常重要的概念——模式-动作；即上述expect "password" {send "$password\r"}这句代码表达出来的含义

刚那是已经有连接过121机器，所以会跳过指纹验证那块，接下来再来，把known_hosts删除，模拟一个全新的ssh连接。注意观察特征

[root@centos7 scripts]# rm ~root/.ssh/known_hosts
rm: remove regular file ‘/root/.ssh/known_hosts’? y

[root@centos7 scripts]# ssh 192.168.2.121                #蓝色表示特征，也就是需要匹配的值，粉红是需要手动输入的，当然password哪里也是需要输入手动密码
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
[root@centos7 scripts]# !rm
rm ~root/.ssh/known_hosts
rm: remove regular file ‘/root/.ssh/known_hosts’? y

[root@centos7 scripts]# vim expect_ssh2.exp
[root@centos7 scripts]# cat expect_ssh2.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"

spawn ssh $username@$host
expect {
    "yes/no" {send "yes\r"}
    "password" {send "$password\r"}
}
interact

[root@centos7 scripts]# ./expect_ssh2.exp
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:                #停留在这里不动了，需要手动输入密码才行

#解决方法：增加exp_continue
[root@centos7 scripts]# vim expect_ssh2.exp
[root@centos7 scripts]# cat expect_ssh2.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"

spawn ssh $username@$host
expect {
    "yes/no" {send "yes\r"; exp_continue}   #类似于while循环里的continue，当匹配到yes/no后，再次进行下次匹配，password，如果还有其它的匹配，那么需要增加exp_continue到倒数第二个匹配里
    "password" {send "$password\r"}
}
interact

[root@centos7 scripts]# ./expect_ssh2.exp
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:23:29 2020 from centos7.lan
[root@Centos6 ~]# ls
anaconda-ks.cfg  install.log  install.log.syslog

[root@centos7 scripts]# vim expect_ssh2.exp
[root@centos7 scripts]# cat expect_ssh2.exp
#!/usr/bin/expect
#
set timeout 30
set host "192.168.2.121"
set username "root"
set password "123.com"

spawn ssh $username@$host
expect {
    "yes/no" {send "yes\r"; exp_continue}
    "password" {send "$password\r"}
}
expect eof                #等待执行结束，若没有这一句，可能导致命令还没执行，脚本就结束了
#interact

[root@centos7 scripts]# ./expect_ssh2.exp
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:38:17 2020 from centos7.lan
[root@Centos6 ~]# ls            #光标卡住不懂了，一直等待超时30秒，然后回到centos7，并且还执行了ls命令
[root@centos7 scripts]# ls
1.txt                disk.sh                ip2.sh         outputKS.sh       select7.sh         trap_test.sh
2.txt                d.txt                  ipaddr.sh      pre.sh            select8.sh         user2.sh
99_2.sh              dysjx.sh               ip.sh          print_action2.sh  service_state2.sh  useradd-1.sh
99.sh                excute.sh              links.sh       print_action.sh   service_state.sh   useradd.sh
argsnum2.sh          expect_ssh2.exp

expect eof：等待执行结束，若没有这一句，可能导致命令还没执行，脚本就结束了
interact：执行完成后保持交互状态, 这时可以手动输入信息
注意：expect eof与interact二选一即可

接收参数
expect参数存在argv中，具体示例说明

[root@centos7 scripts]# vim expect_ssh3.exp
[root@centos7 scripts]# cat expect_ssh3.exp
#!/usr/bin/expect
#
set timeout 30
set host [lindex $argv 0]
set username [lindex $argv 1]
set password [lindex $argv 2]

if { $argc < 3} {     #注意}{这两个之间是有空格的，而且在expect里，if条件时用大括号而非bash []或者其他语言的（）;$argc就是参数个数，相当于$#，可以如此记忆，arg是参数，后面的c表示count，个数的意思；$argv，后面的v表示value，值得意思
#     puts "Usage:argv0 <host> <username> <password>\n"        #puts和send_user相同功能，类似bash shell中的echo -e
     send_user "Usage:$argv0 <host> <username> <password>\n"   #$argv0是脚本名，但是[lindex $argv 0]是第一个参数，[lindex $argv 1]是第二个参数，依次类推；$argv0相当于bash位置变量的$0，[lindex $argv 1]相当于$1
     exit
}

spawn ssh $username@$host
expect {
    "yes/no" {send "yes\r"; exp_continue}
    "password" {send "$password\r"}
}
interact

[root@centos7 scripts]# ./expect_ssh3.exp 192.168.2.121 root 123.com
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:46:25 2020 from centos7.lan
[root@Centos6 ~]# ls
anaconda-ks.cfg  install.log  install.log.syslog

执行多个命令
结尾就不需要使用interact，而使用expect eof，毕竟不需要停留在对方终端上
这里通过“]#”来做匹配；创建kyle用户

[root@Centos6 ~]# getent passwd kyle
[root@Centos6 ~]#

[root@centos7 scripts]# vim expect_ssh4.exp
[root@centos7 scripts]# cat expect_ssh4.exp
#!/usr/bin/expect
#
set timeout 30
set host [lindex $argv 0]
set username [lindex $argv 1]
set password [lindex $argv 2]

if { $argc < 3} {
#   puts "Usage:argv0 <host> <username> <password>\n"
    send_user "Usage:$argv0 <host> <username> <password>\n"
    exit
}

spawn ssh $username@$host
expect {
    "yes/no" {send "yes\r"; exp_continue}
    "password" {send "$password\r"}
}
expect "]#" {send "useradd kyle\r"}
expect "]#" {send "echo 123.com | passwd --stdin kyle\r"}
expect eof

[root@centos7 scripts]# ./expect_ssh4.exp 192.168.2.121 root 123.com
spawn ssh [email protected]
The authenticity of host '192.168.2.121 (192.168.2.121)' can't be established.
RSA key fingerprint is SHA256:oOQ2p3kF0ksYSimQxOywI9zkxFOx0JARw5aIkfO/eqQ.
RSA key fingerprint is MD5:6c:d9:39:01:d9:a5:16:68:b1:1e:c1:5f:7f:b5:fa:b3.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.121' (RSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Jun 21 14:46:33 2020 from centos7.lan
[root@Centos6 ~]# useradd kyle
[root@Centos6 ~]# echo 123.com | passwd --stdin kyle
Changing password for user kyle.
passwd: all authentication tokens updated successfully.

#切换到121机器上查看，因为之前写的脚本结束是expect eof，所以不能直接在121上操作。xshell连接到121上查看用户是否已经创建，其实上面红色标记已经显示很清楚已经创建了
[root@Centos6 ~]# getent passwd kyle            #已经创建kyle用户，并且已经设置了密码
kyle:x:500:500::/home/kyle:/bin/bash
[root@Centos6 ~]# getent shadow kyle
kyle:$6$S.NY9Bt0$R2sVfsh7G3gLgviVt/cTZxWhoLRIfeJ.slX.j3z2OOS8kANN6g1YU6j.Wc3U6rX20kn70TjayN5jrgw3LfAeK.:18434:0:99999:7:::

shell脚本调用expect
同样是上面脚本的改进，这次是增加kevin这个用户，并设置密码，同时也解决之前，执行完脚本后会停留在121终端上的问题

[root@Centos6 ~]# getent passwd kevin
[root@Centos6 ~]#

[root@centos7 scripts]# vim expect_ssh5.sh
[root@centos7 scripts]# cat expect_ssh5.sh
#!/bin/bash
#
host=$1
username=$2
password=$3

if [ "$#" -lt 3 ];then              #与之前expect编写参数用法对照看
    echo  "Usage:$0 <host> <username> <password>"
    exit
fi

expect << EOF
spawn ssh $username@$host
expect {                            #注意，在shell调用expect脚本中大括号都需要空格，不像之前直接expect那样，不需要空格
    "yes/no" { send "yes\r"; exp_continue }
    "password" { send "$password\r" }
}
expect "]#" { send "useradd kevin\r" }
expect "]#" { send "echo 123.com | passwd --stdin kevin\r" }
expect "]#" { send "exit\r" }       #增加这条expect后，就不需要再停留在121机器上了
expect eof
EOF

[root@centos7 scripts]# ./expect_ssh5.sh 192.168.2.121 root            #能判断参数
Usage:./expect_ssh5.sh <host> <username> <password>

[root@centos7 scripts]# ./expect_ssh5.sh 192.168.2.121 root 123.com    #完全自动化操作，非人工输入
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Jun 21 15:26:47 2020 from centos7.lan
[root@Centos6 ~]# useradd kevin
[root@Centos6 ~]# echo 123.com | passwd --stdin kevin
Changing password for user kevin.
passwd: all authentication tokens updated successfully.
[root@Centos6 ~]# exit
logout
Connection to 192.168.2.121 closed.
[root@centos7 scripts]#

#验证结果如下
[root@Centos6 ~]# getent passwd kevin
kevin:x:502:502::/home/kevin:/bin/bash
[root@Centos6 ~]# getent shadow kevin
kevin:$6$iL5UNV/1$0ofohxfg8qUIM1Cxf8swxBqaZ2yyTVVdcw8.ynUNVe5Nhj/Dg3DDxTRWuEDnQd5IQ.Xyf.xHQQcdKC3eNCGeV1:18434:0:99999:7:::

猜你喜欢

转载自blog.51cto.com/14812296/2518570
今日推荐
火速冲上 GitHub 热榜 —— 开源编程语言、框架哪有这么可爱？
北京人形机器人创新中心发布全球首个纯电驱拟人奔跑的全尺寸人形机器人“天工”
LFOSSA 源来如此公开课 | 掌握云原生未来：CNCF 认证全面攻略与备考秘籍
国产云输入法——仅华为无云端数据上传安全问题
开源日报 | 工业开源项目OGG 1.0；姐姐，你要和我一起配置火狐吗；苹果AI遥遥落后？Fedora 40
开放签电子签章：停止新增，优化体验，前进更进（五一假期前工作）
开源日报 | 中学生开源前端动画引擎；全球首个Llama3 8B中文版开源模型；联想电脑恐出局；Linus讽刺AI炒作
周排行
浏览器对同一域名进行请求的最大并发连接数
React Hook之自定义Hook
【转】MyBatis缓存机制
-Java-泛型
自动化测试常用脚本-发送邮件
LeetCode#859: Buddy Strings
java、Python处理字符串
第二篇の博客
Hadoop伪分布式环境安装
SQL Server进阶（十一）临时表、表变量
每日归档
更多
2024-04-27(56)
2024-04-26(39)
2024-04-25(22)
2024-04-24(36)
2024-04-23(26)
2024-04-22(39)
2024-04-21(0)
2024-04-20(6)
2024-04-19(5)
2024-04-18(0)

代码天地 © 2018 codetd.com

境外服务器   最新电视剧2022