交互式转化批处理工具 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 处理交互的命令，可以将交互过程如：ssh登录，ftp登录等写在一个脚本上，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中，可以大大提高系统管理人员的工作效率

expect 语法：

expect [选项] [ -c cmds ] [ [ -[f|b] ] cmdfile ] [ args ]

常见选项：

-c：从命令行执行expect脚本，默认expect是交互地执行的

-d：可以输出输出调试信息

示例：

expect -c 'expect "\n" {send "pressed enter\n"}'
expect  -d ssh.exp

expect中相关命令

• spawn 启动新的进程
• expect 从进程接收字符串
• send 用于向进程发送字符串
• interact 允许用户交互
• exp_continue 匹配多个字符串在执行动作后加此命令

expect最常用的语法(tcl语言:模式-动作)

单一分支模式语法：

[root@centos8 test]#expect
expect1.1> expect "hi" {send "You said hi\n"}
hahahixixi
You said hi

匹配到hi后，会输出“you said hi”，并换行

多分支模式语法：

[root@centos8 test]#expect
expect1.1> expect "hi" { send "You said hi\n" } "hehe" { send "Hehe yourself\n" } "bye" { send "Good bye\n" }
hehe
Hehe yourself
expect1.2> expect "hi" { send "You said hi\n" } "hehe" { send "Hehe yourself\n" } "bye" { send "Good bye\n" }
bye
Good bye
expect1.3> expect "hi" { send "You said hi\n" } "hehe" { send "Hehe yourself\n" } "bye" { send "Good bye\n" }
hi
You said hi
expect1.4>

匹配hi,hello,bye任意字符串时，执行相应输出。等同如下：

expect {
    "hi" { send "You said hi\n"}
    "hehe" { send "Hehe yourself\n"}
    "bye" { send  " Good bye\n"}
}

范例1：

#!/usr/bin/expect
spawn scp /etc/fstab 10.0.0.7:/data
expect {
        "yes/no" { send "yes\n";exp_continue }
        "password" { send  "magedu\n" }
}
expect eof

范例2：

#!/usr/bin/expect
spawn ssh 10.0.0.7
expect {
        "yes/no" { send "yes\n";exp_continue }
        "password" { send  "magedu\n" }
}
interact

范例3：expect 变量

#!/usr/bin/expect
set ip 10.0.0.7
set user root
set password magedu
set timeout 10
spawn ssh $user@$ip
expect {
        "yes/no" { send "yes\n";exp_continue }
        "password" { send "$password\n" }
}
interact

范例4：expect 位置参数

#!/usr/bin/expect
set ip [lindex $argv 0] 
set user [lindex $argv 1]
set password [lindex $argv 2]
spawn ssh $user@$ip
expect {
        "yes/no" { send "yes\n";exp_continue }
        "password" { send "$password\n" }
}
interact
#./ssh3.exp 192.168.8.10 root magedu

范例5：expect 执行多个命令

#!/usr/bin/expect
set ip [lindex $argv 0] 
set user [lindex $argv 1]
set password [lindex $argv 2]
set timeout 10
spawn ssh $user@$ip
expect {
        "yes/no" { send "yes\n";exp_continue }
        "password" { send "$password\n" }
}
expect "]#" { send "useradd haha\n" }
expect "]#" { send "echo magedu |passwd --stdin haha\n" }
send "exit\n"
expect eof
#./ssh4.exp 10.0.0.7 root magedu

范例6：shell脚本调用expect

#!/bin/bash
ip=$1 
user=$2
password=$3
expect <<EOF
set timeout 20
spawn ssh $user@$ip
expect {
        "yes/no" { send "yes\n";exp_continue }
        "password" { send "$password\n" }
}
expect "]#" { send "useradd hehe\n" }
expect "]#" { send "echo magedu |passwd --stdin hehe\n" }
expect "]#" { send "exit\n" }
expect eof
EOF 

#./ssh5.sh 192.168.8.10 root magedu

范例7: shell脚本利用循环调用expect在CentOS和Ubuntu上批量创建用户

#!/bin/bash
#
#********************************************************************
#Author:        wangxiaochun
#QQ:            29308620
#Date:          2020-01-06
#FileName：      expect6.sh
#URL:           http://www.magedu.com
#Description：       The test script
#Copyright (C):     2020 All rights reserved
#********************************************************************
NET=10.0.0
user=root
password=magedu

for ID in 6 7 111;do
ip=$NET.$ID

expect <<EOF
set timeout 20
spawn ssh $user@$ip
expect {
        "yes/no" { send "yes\n";exp_continue }
        "password" { send "$password\n" }
}
expect "#" { send "useradd test\n" }
expect "#" { send "exit\n" }
expect eof
EOF
done

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