如何在期望脚本中“导出”变量？

Question

我正在尝试自动化一些用于设置打印机的 telnet 命令。如果我手动执行，终端的预期输出如下：

Ebins-Mac-Mini:~ ebin$ telnet 192.168.4.104
Trying 192.168.4.104...
Connected to 192.168.4.104.
Escape character is '^]'.


Welcome to TSP100LAN TELNET Utility.
Copyright(C) 2008 Star Micronics co., Ltd.

<< Connected Device >>
   Device Model : TSP143 (STR_T-001)
   MAC Address  : 00:11:62:08:5B:F6

login: root         
password: ******

Hello root

=== Main Menu ===
  1) IP Parameters Configuration
  2) System Configuration
  3) Change Password
 96) Display Status
 97) Reset Settings to Defaults
 98) Save & Restart
 99) Quit

Enter Selection: 1

=== IP Parameters Menu ===
  1) Static
         IP Address      : 192.168.4.104
         Subnet Mask     : 255.255.255.0
         Default Gateway : 192.168.4.1
  2) Dynamic
         DHCP            : DISABLE
 99) Back to Main Menu

Enter Selection: 1

=== Static IP Address ===
  1) IP Address      : 192.168.4.104
  2) Subnet Mask     : 255.255.255.0
  3) Default Gateway : 192.168.4.1
 99) Back to IP Address Menu

Enter Selection: 

在第二次选择之前，我设法完成了它。但是，对于第二个选择，IP 地址：192.168.4.104 应该是我作为参数传递的变量。我如何“期待”这个？以下是我目前的代码。

#!/usr/bin/expect -f
        set timeout 20
    set IPaddress [lindex $argv 0]

    set Username "root"
    set Password "public"
    spawn telnet $IPaddress
    expect "login: "
    send "$Username\r"
    expect "password: "
    send "$Password\r"
    expect {"Hello root\n\n"
        "=== Main Menu ===\n"
        "1) IP Parameters Configuration\n"
        "2) System Configuration\n"
        "3) Change Password\n"
        "96) Display Status\n"
        "97) Reset Settings to Defaults\n"
        "98) Save & Restart\n"
        "99) Quit\n\n"
        "Enter Selection:"
    }
    send 1
    send "\r"
    expect {"=== IP Parameters Menu ===\n"
        " 1) Static\n"
        " IP Address      : "
        "$IPaddress\n"
        " Subnet Mask     : 255.255.255.0\n"
        " Default Gateway : 192.168.4.1\n"
        " 2) Dynamic\n"
        " DHCP            : DISABLE\n"
        " 99) Back to Main Menu\n\n"
        " Enter Selection: "
    }
    send 1
    send "\r"

程序似乎超时并退出。我怀疑我写错了期望行。任何帮助，将不胜感激。

Answer 1

不要“期待”完整的输出；相反，只需专注于唯一标识您正在执行的任何操作的当前状态的序列。在您的情况下，这可能是菜单标题，例如“=== Main Menu ===”。如果您事先知道每次显示某某菜单时都会选择选项 X，那么这是处理它的最佳方式。期望过高容易出错。

编辑： 这是一个示例 sn-p：

expect "=== Main Menu ==="
send "1\r"
expect "=== IP Parameters Menu ==="
send "1\r"