bash是通过$0 ... $n接收参数

expect是通过set <变量名称> [lindex $argv <param index>],
例如：set username [lindex $argv 0]

#!/usr/bin/expect  
set timeout 10  
set username [lindex $argv 0]  
set password [lindex $argv 1]  
set hostname [lindex $argv 2]  
spawn ssh $username@$hostname  
expect "yes/no"  
send "yes\r"  
expect "password:" 
send "$password\r"
expect eof

执行脚本./ssh.exp root pasword hostname1

一个比较粗糙的 Linux expect 通过 telnet console 口配置网络设备

#!/bin/bash
PORT=$1
cmd="""sys\r
interface g1/1\r
 ip add 1.1.1.1 24\r"""
# 执行 expect
# 每个 expect 的判断间隔为 5 秒，确保命令可以正常退出
# expect 可以通过发送 ascii 码来执行键盘组合
expect <<END
    set timeout 5
    spawn telnet 10.0.0.1 1111
    expect "*]'" { send "\r" }
    expect "*assword:" { send "P@ssword\r" }
    expect {
        "*>" { send "screen disable\r" }
        "*]" { send "screen disable\r" }
    }
    expect {
        "*>" { send "$cmd" }
        "*]" { send "$cmd" }
    }
    expect "*]" { send "\03" }
    expect eof
END

expect 可以通过发送 ascii 码来执行键盘组合
expect语法介绍

=====
通过 expect 进行ssh登录并停留在交互界面

#!/bin/bash
PASSWD='Lu@$\(..QXoTFu!'
sw_login(){
        expect -c "
        # 每个判断等待两秒
        set timeout 2
        spawn bash -c \"ssh cloudnet@$1\"
        # 判断是否需要保存秘钥
        expect {
                \"yes/no\"   { send yes\n }
        }
        # 判断发送密码
        expect {        
        \"*assword\" { send $PASSWD\n }
        }
        # 停留在当前登录界面
        interact
        "
}
sw_login $1