Shell Programming Expect free interaction
Expect Overview
Expect installation
Expect basic commands
Expect implementation
Expect Case
Expect Overview
Expect
ExpectIt is built tclon the basis of a tool, Expecta tool used for automated control and testing. Mainly to solve the shellproblem of non-interactive script. For large-scale linuxoperation and maintenance helpful- In the
linuxoperation and maintenance and development, we often need to operate a remote login server, the login process is an interactive process, you may need to enter yes/no passwordother information. To simulate this input, you can use the Expectscript
Expect installation
Mount CD
To make a local YUM source
The installation command
[root@localhost ~]# yum install expect -y
已加载插件：fastestmirror, langpacks
base | 3.6 kB 00:00:00
extras | 2.9 kB 00:00:00
updates | 2.9 kB 00:00:00
(1/4): extras/7/x86_64/primary_db | 152 kB 00:00:00
(2/4): base/7/x86_64/group_gz | 165 kB 00:00:00
(3/4): updates/7/x86_64/primary_db | 1.9 MB 00:00:01
...//省略部分内容...
正在安装 : 1:tcl-8.5.13-8.el7.x86_64 1/2
正在安装 : expect-5.45-14.el7_1.x86_64 2/2
验证中 : 1:tcl-8.5.13-8.el7.x86_64 1/2
验证中 : expect-5.45-14.el7_1.x86_64 2/2
已安装:
expect.x86_64 0:5.45-14.el7_1
作为依赖被安装:
tcl.x86_64 1:8.5.13-8.el7
完毕！
Expect basic commands
send: send the string to the process used to simulate the user's input
- This command does not automatically carriage return line, typically to add
\r(carriage return)
expect
expectAn internal command, output in the last judgment contains a specified string, if there is an immediate return, otherwise wait timeout return.- Can only be captured by the
spawnoutput of the process started
spawn: start the process, and subsequent interaction tracking information
interact: to maintain the cross-state execution is completed, the control to the console
Timeout: Specifies the timeout expired proceed to follow instructions
- The unit is: seconds
timeout -1To never timeout- By default,
timeouta 10second
exp_ continue
- Allowed to
expectcontinue executing instructions down
send_ user
- Echo command, equivalent to
echo
$ Argv array of parameters
ExpectScripts can be accepted from the bashparameters passed can be used [lindex $argv n]to obtain, nfrom 0the beginning, represent the first, second, third argument ...
Expect script must interact or expect eof end, perform automated tasks typically expect eof enough
expect eofWe are waiting for the end of the flag. By the spawncommand to start will produce at the end of a eofmark, expect eofRoyal waiting for this tag
Expect grammar
Single branch grammar
expect "password:" {send "mypassword\r";}
Multi-drop mode syntax
expect "aaa" {send"AAA\r"} //send命令不具备回车换行功能，一般要加\r或\n
expect "aaa" {send"AAA\r"}
expect "aaa" {send"AAA\r"}
expect {
"aaa" {send "AAA\r"} //只要配置aaa或bbb或ccc中的任何一个，执行相应的send语句后退出该expect语句
"bbb" {send "BBB\r"}
"ccc" {send "CCC\r"}
}
expect {
"aaa" {send "AAA";exp_continue} //exp_continue表示继续后面的匹配，如果匹配了aaa，执行
"bbb" {send "BBB";exp_continue} 完send语句后还要继续向下匹配bbb
"ccc" {send "CCC"}
}
Expect implementation
Direct execution
- Use
expectfree interactive use sshTelnet to another server, and here I turn on two Linuxservers.
[root@localhost ~]# vim demo19.sh //编辑脚本文件
#!/usr/bin/expect //expect二进制文件路径
set timeout 5 //超时时间
log_file tast.log //记录日志文件存放位置
log_user 1 //一个用户
set hostname [lindex $argv 0] //设定第一个位置参数传递并设置变量名hostname
set password [lindex $argv 1] //设定第二个位置参数传递并设置变量名password
spawn ssh root@$hostname //追踪命令
expect { //使用expect命令捕捉条件，设定输入信息，进行免交互设置
"(yes/no)" //设定匹配条件
{send "yes\r";exp_continue} //条件匹配并输入内容，并继续向下匹配
"*password" //设定匹配条件
{send "$password\r"} //条件匹配，引用位置变量输入信息
}
interact //完成后将控制权交给控制台
[root@localhost ~]# chmod +x demo19.sh //给脚本文件添加执行权限
[root@localhost ~]# ./demo19.sh 192.168.144.135 123123 //执行脚本
spawn ssh [email protected]
The authenticity of host '192.168.144.135 (192.168.144.135)' can't be established.
ECDSA key fingerprint is SHA256:B8IsZOFG7FbtVkIK+dMILmo0iA4OEIeVGY0GnnCbXhk.
ECDSA key fingerprint is MD5:c2:d8:09:17:de:6e:ec:07:06:1b:ac:b6:1e:bd:62:09.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.144.135' (ECDSA) to the list of known hosts.
[email protected]'s password:
Last login: Sun Oct 13 23:29:38 2019 from 192.168.144.1 //自动登录服务器
[root@localhost ~]# ifconfig //查看服务器IP地址
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.144.135 netmask 255.255.255.0 broadcast 192.168.144.255 //成功登录
inet6 fe80::a85a:c203:e2e:3f3c prefixlen 64 scopeid 0x20<link>
inet6 fe80::ad78:663f:1f02:22e4 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:75:9f:c8 txqueuelen 1000 (Ethernet)
...//省略部分内容...
Embed execution
[root@localhost ~]# vim demo20.sh //编辑脚本文件
#!/bin/bash
hostname=$1 //设置位置参数变量
password=$2
/usr/bin/expect <<-EOF //加载expect功能，EOF前面加“-”是为增加容错性，-EOF 前面的“-"只能容错制表
spawn ssh root@$hostname 符，不能容错空格
expect {
"(yes/no)"
{send "yes\r";exp_continue} //进行免交互配置
"*password"
{send "$password\r"}
}
expect "*]#" //捕捉内容结尾为“]#”的内容
send "exit\r" //匹配后输入exit退出登录
expect eof //等待结束标志
EOF //结束标志
[root@localhost ~]# chmod +x demo20.sh //添加执行权限
[root@localhost ~]# ./demo20.sh 192.168.144.135 123123 //执行脚本，并输入位置变量
spawn ssh [email protected]
[email protected]'s password:
Last login: Sun Oct 13 23:58:05 2019 from 192.168.144.1
[root@localhost ~]# exit
登出
Connection to 192.168.144.135 closed.
[root@localhost ~]# ifconfig //查看IP地址信息
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.144.133 netmask 255.255.255.0 broadcast 192.168.144.255
inet6 fe80::a85a:c203:e2e:3f3c prefixlen 64 scopeid 0x20<link> //成功登出
ether 00:0c:29:5b:d3:a0 txqueuelen 1000 (Ethernet)
RX packets 11058 bytes 855440 (835.3 KiB)
...//省略部分内容...