预期错误处理-生成id未打开

我正在编写一个expect脚本,它可以注销数百个路由器并更改其配置。

我的问题是,路由器固件上有一个bug,导致它们在发送密码后关闭连接。 如果我再次登录,它可以正常工作(因此只有在重新启动后第一次登录才会导致异常)。 当连接关闭时,expect脚本终止。

我希望我能优雅地捕捉到异常,然后再试一次。

失败的代码是这一部分:

# go through each IP
for {set i $start} {$i <= $end} {incr i} {
  set ip "10.$octet2.$i.x"

  puts "\n\n\n#### doing $ip...\n" ; flush stdout

  # log in to the IP
  spawn ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -l $user $ip
  expect {
    "continue connecting (yes/no)?" { send "yes\r" ; exp_continue }
    "login as: " { send "$user\r" ; exp_continue }
    "Password: " { send "$pwd\r" }
    "No route to host" { continue }
    timeout { continue }
    }

  # execute commands from file
  foreach c "$commands" { eval $c }

  }

我得到的错误如下所示:

Password:
Connection to 10.x.x.x closed by remote host.
Connection to 10.x.x.x closed.
send: spawn id exp11 not open
    while executing
"send "exit\r""
    ("eval" body line 1)
    invoked from within
"eval $c "
    ("foreach" body line 1)
    invoked from within
"foreach c "$commands" { eval $c }"
    ("for" body line 18)
    invoked from within
"for {set i $start} {$i <= $end} {incr i} {
  set ip "10.$octet2.$i.x"

  puts "\n\n\n#### doing $ip...\n" ; flush stdout

  # log in to the IP
  spa..."
    (file "./multido.exp" line 39)

非常感谢您的帮助!