无法在 expect 脚本中正确获取 "ps" 命令的输出

Question

我已经在下面复制了我的脚本。对于变量 "userName" 我没有在正确的地方得到预期的输出。预期的输出是 "pload"，它在最后。对此有何正确建议？

脚本：

#!/usr/bin/expect
exp_internal 1
set timeout 30
set prompt {[$]}
spawn ssh -o StrictHostKeyChecking=no $username@$server.com
expect "assword"
send $password\r
expect "$prompt"
expect *
send "ps aux | grep -v grep | tr ' ' '\n' | grep pload | uniq\r"
expect -re "(.*)\n"
sleep 20
set userName $expect_out(buffer)
puts "buffer:$userName end"
if { $userName eq "pload" } {
   send "sudo su - pload\r"
} else {
send "sudo su - pdev\r"
}
expect "assword"
send $password\r
expect "$prompt"

日志如下：

.
.
3997@fd0441a2:~\u0007\u001b[?1034h[f5103997@fd0441a2 ~]$"
expect: does " " (spawn_id exp4) match glob pattern "*"? yes
expect: set expect_out(0,string) " "
expect: set expect_out(spawn_id) "exp4"
expect: set expect_out(buffer) " "
send: sending "ps aux | grep -v grep | tr ' ' '\n' | grep pload | uniq\r" to { exp4 }
Gate keeper glob pattern for '(.*)
' is '*
'. Activating booster.

expect: does "" (spawn_id exp4) match regular expression "(.*)\n"? Gate "*\n"? gate=no
ps aux | grep -v grep | tr ' ' '\n' | grep pload | uniq

expect: does "ps aux | grep -v grep | tr ' ' '\n' | grep pload | uniq\r\n" (spawn_id exp4) match regular expression "(.*)\n"? Gate "*\n"? gate=yes re=yes
expect: set expect_out(spawn_id) "exp4"
expect: set expect_out(buffer) "ps aux | grep -v grep | tr ' ' '\n' | grep pload | uniq\r\n"
buffer:ps aux | grep -v grep | tr ' ' '\n' | grep pload | uniq
 end
send: sending "sudo su - pdev\r" to { exp4 }

expect: does "" (spawn_id exp4) match glob pattern "assword"? no
pload
[f5103997@fd0441a2 ~]$
expect: does "pload\r\n\u001b]0;f5103997@fd0441a2:~\u0007[f5103997@fd0441a2 ~]$ " (spawn_id exp4) match glob pattern "assword"? no
sudo su - pdev

Answer 1

我建议对预期代码进行一些修改：

使用expect -re并使用模式。例如，提示设置为 [f5103997@fd0441a2 ~]$，但要匹配的模式是 [$]。 expect -re {.*$]\s*} 更好，IMO。

在第一次登录后立即将默认提示更改为已知值（没有任何 TCL 特殊字符（如 $ 和 [）。应该执行下一组命令顺利。我试过了，这是一个片段：

expect -re {.*[pP]assword}
send $password\r
expect -re "$prompt"
set newPrompt {MY_NEW_PROMPT> }
send "export PS1=\"$newPrompt\"\r"
expect -re ".*$newPrompt"
send "\r"
after 2000 ;# flush out the MOTD, etc.
expect -re ".*$newPrompt"
send "pwd\r"
expect -re ".*$newPrompt"
puts -->$expect_out(buffer)
send "exit\r"

输出：

sharad@sharad:~$ expect sharad.expect
spawn ssh -o StrictHostKeyChecking=no sharad@localhost
sharad@localhost's password: 
export PS1="MY_NEW_PROMPT> "

Welcome to Ubuntu 16.04.1 LTS (GNU/Linux 4.4.0-53-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

175 packages can be updated.
4 updates are security updates.

export PS1="MY_NEW_PROMPT> "

Last login: Fri Dec 23 23:02:22 2016 from 127.0.0.1
sharad@sharad:~$ export PS1="MY_NEW_PROMPT> "
MY_NEW_PROMPT> 
MY_NEW_PROMPT> pwd
/home/sharad
MY_NEW_PROMPT> -->pwd
/home/sharad
MY_NEW_PROMPT> 
sharad@sharad:~$

Answer 2

我通常会在命令的输出周围放置一些特殊字符，这样编写 expect RE 会更容易一些。所以像这样尝试：

send "echo ==\">$(ps aux | grep -v grep | tr ' ' '\n' | grep pload | uniq)<\"==\r"
expect -re "==>(.*)<=="
set userName $expect_out(1,string)
#                        ^^^^^^^^
expect "$prompt"

无法在 expect 脚本中正确获取 "ps" 命令的输出

Not able to get output of "ps" command properly in expect script

tcl

expect