如何在期望会话中使用shell变量? [英] how to use shell variable in expect session?

问题描述

我尝试使用bash脚本中的 scp 将一些文件发送到多个服务器.但是我遇到了问题.

I try so send some files toward multiple servers using scp in bash script. But I encountering problem.

这是我写的shell脚本.

here is the shell script I wrote.

#!/bin/sh

IP_LIST=('127.0.0.x' '127.0.0.y' '127.0.0.z')

for ip_addr in "${IP_LIST[@]}"
do
        echo "$ip_addr"
expect << 'EOS'
        set timeout 10
        spawn scp -p /home/foo/bar/baz.txt user@"$ip_addr":/home/destdir
        expect "*password*"
        send "pasword\r"
        expect eos
        exit 0
EOS
done

我假设 ip_addr 中的每个元素都分配给变量 ip_addr ，但在 expect 会话中，未分配列表中的元素.

I assume each element in ip_addr is assigned to the variable ip_addr, but in expect session, element in the list doesn't assigned.

当我执行此脚本时，会出现这样的错误消息.

When I execute this script, such error message appear.

can't read "ip_addr": no such variable  
    while executing
"spawn scp -p /home/foo/bar/baz.txt user@"$ip_addr":/home/destdir"

在使用 echo 命令(在 IP_LIST 中显示每个元素)时有效.

It works when use echo command(displays each element in IP_LIST).

有人知道一些好主意吗?

anybody know some good idea?

推荐答案

对于shell的<<STRING 语法，如果引用了 STRING ，则它不会扩展变量，因此您的 $ ip_addr 仍然是 $ ip_addr 到期望脚本，但未在期望中定义.您可以使用env var从 shell 将 ip_addr 从 shell 传递给 Expect .例如:

For shell's << STRING syntax, if STRING is quoted then it'll not expand variables so your $ip_addr is still $ip_addr to the Expect script but it's not defined in Expect. You can pass the ip_addr from shell to Expect with the env var. E.g.:

#!/bin/sh

IP_LIST=('127.0.0.x' '127.0.0.y' '127.0.0.z')

for ip_addr in "${IP_LIST[@]}"
do
    echo "$ip_addr"
    ip_addr=$ip_addr expect << 'EOS'
      set timeout 10
      spawn scp -p /home/foo/bar/baz.txt user@$::env(ip_addr):/home/destdir
      expect "*password*"
      send "pasword\r"
      expect eos; # do you mean `eof'?
      exit 0
EOS
done

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