1. expect语法
expect [options] [commands/command file]
Expect 程序使用以下关键字与其他程序进行交互：
| 命令 | 功能 |
| spawn | 创建一个启动新的交互进程, 后面跟命令或者指定程序进程 |
| send | 向进程发送字符串 |
| expect | 从进程中接收信息, 如果匹配成功, 就执行expect后的动作 |
| interact | 允许用户交互 |
| set timeout | 设置超时时间 |
| send_user | 用来打印输出，相当于shell中的echo |
| exp_continue | 在expect中多次匹配就需要用到 |
| exit | 退出expect脚本 |
| set | 定义变量 |
Expect 使用 TCL（工具命令语言）来控制程序流和必要的交互。
2. 安装和使用
# 安装
yum install expect
# 脚本首行
#!/usr/bin/expect
# 使用示例
创建交互脚本interactive_script.sh
#!/bin/bash
echo "Hello, who is this?"
read $REPLY
echo "What's your favorite color?"
read $REPLY
echo "How many cats do you have?"
read $REPLY
创建expect脚本expect_response.exp
#!/usr/bin/expect
spawn ./interactive_script.sh
expect "Hello, who is this?\r"
send -- "小明\r"
expect "What's your favorite color?\r"
send -- "蓝色\r"
expect "How many cats do you have?\r"
send -- "1个\r"
expect eof
# 执行
./expect_response.exp
or
expect expect_response.exp
3. expect和变量
#!/usr/bin/expect
set NAME "Li Ming"
set COLOR "Blue"
set NUMBER [lindex $argv 0]
spawn ./interactive_script.sh
expect "Hello, who is this?\r"
send -- "$NAME\r"
expect "What's your favorite color?\r"
send -- "$COLOR\r"
expect "How many cats do you have?\r"
send -- "$NUMBER\r"
expect eof