需要先安装expect

yum -y install expect

expect 语法

expect [选项] [ -c cmds ] [ [ -[f|b] ] cmdfile ] [ args ]
选项
-c：从命令行执行expect脚本，默认expect是交互地执行的
示例：expect -c 'expect "\n" {send "pressed enter\n"}
-d：可以输出输出调试信息
示例：expect -d ssh.exp

expect中相关命令
spawn 启动新的进程
send 用于向进程发送字符串
expect 从进程接收字符串
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：
expect “hi” {send “You said hi\n"}
匹配到hi后，会输出“you said hi”，并换行
多分支模式语法：
expect "hi" { send "You said hi\n" } \
"hehe" { send "Hehe yourself\n" } \
"bye" { send "Good bye\n" }
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"}
}

示例

#!/usr/bin/expect
spawn scp /etc/fstab 192.168.8.100:/app
expect {
 "yes/no" { send "yes\n";exp_continue }
 "password" { send "abc\n" }
}
expect eof

#!/usr/bin/expect
spawn ssh 192.168.8.100
expect {
 "yes/no" { send "yes\n";exp_continue }
 "password" { send "abc\n" }
}
interact
#expect eof

#!/usr/bin/expect
set ip 192.168.8.100
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

实例：位置参数

[lindex $argv 0] 相当于shell中的$1

[lindex $argv 1] 相当于shell中的$2

#!/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 192.168.8.100 root magedu

示例：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 abc |passwd --stdin haha\n" }
send "exit\n"
expect eof
#./ssh4.exp 192.168.8.100 root magedu

示例：shell脚本调用expect

用多行重定向来写expect的语句块

expect <<EOF

...

...

...

EOF

#!/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 abc |passwd --stdin hehe\n" }
expect "]#" { send "exit\n" }
expect eof
EOF
#./ssh5.sh 192.168.8.100 root abc