在远程计算机上运行 cat 并使用 Expect 发送输出变量

Question

我有一个 bash+expect 脚本，它必须通过 ssh 连接到远程计算机（我不能使用 ssh 密钥，需要在此处进行密码识别），读取那里的文件，找到带有“主机名”的特定行（例如“ hostname aaaa1111") 并将该主机名存储到稍后使用的变量中。如何获取“主机名”参数的值？我认为该行内容将位于 $expect_out(buffer) 变量中（这样我可以扫描它并分析），但事实并非如此。我的脚本是：

    #!/bin/bash        
    ----bash part----
    /usr/bin/expect << ENDOFEXPECT
    spawn bash -c "ssh root@$IP"  
    expect "password:"
    send "xxxx\r"
    expect ":~#"
    send "cat /etc/rc.d/rc.local |grep hostname \r"
    expect ":~#"
    set line $expect_out(buffer)
    puts "line = $line, expect_out(buffer) = $expect_out(buffer)"
    ...more script...
    ENDOFEXPECT

当我尝试查看行变量时，我只看到这个： line = , Expect_out(buffer) = (buffer) 将行从文件获取到变量的正确方法是什么？ 或者是否可以使用expect打开远程计算机上的文件，扫描文件并获取变量所需的内容？ 这里 http://en.wikipedia.org/wiki/Expect 有一个例子：

    # Send the prebuilt command, and then wait for another shell prompt.
    send "$my_command\r"
    expect "%"
    # Capture the results of the command into a variable. This can be displayed, 
    set results $expect_out(buffer)

似乎在这种情况下不起作用？

Answer 1

你可能只想尝试从expect中完成这一切，因为expect可以控制bash。

以下应该执行您所描述的操作。不确定这是否正是您想要做的。

#!/bin/sh
# the next line restarts using tclsh \
exec expect "$0" "$@"


spawn bash 
send "ssh root@$IP\r"
expect "password:"
send "xxxx\r"
expect ":~#"
send "cat /etc/rc.d/rc.local |grep hostname \n"
expect ":~#"
set extractedOutput $expect_out(buffer)
set list [split $extractedOutput "\n"]
foreach line $list {
    set re {(?x)
        .*
        (*)              
        -S.*
    }
    regexp $re $line total extractedValue
    if {[info exists extractedValue] && [string length $extractedValue] > 1} {
        set exportValue $extractedValue
        break    # We've got a match!
}

send "exit\r" # disconnect from the ssh session

if {[info exists exportValue] && [string length $exportValue] > 1}{
    send "export VARIABLE $exportValue\r"
} else {
    send_user "No exportValue was found - exiting\n"
    send "exit\r"
    close
    exit 1
}

# now you can do more things in bash if you like