如何以root身份远程运行命令？

Question

我尝试以userA身份登录服务器，然后切换到root帐户并运行一些命令。步骤应该是：

1. ssh userA@10.0.0.1
2. su - root
3. WHOAMI

我使用下面的代码实施了第1步，但不知道如何实施第2步和第3步。

#!/usr/bin/expect -f
set timeout 12
set password_root 12345678
set password_A 12345678

spawn ssh -t sflow@10.0.0.1
expect -re ".*password:"
send "$password_sflow\r"
expect eof

Answer 1

#!/usr/bin/expect
set timeout 12
set password_root 12345678
set password_A 12345678

set prompt "#|>|\\\$ $"
spawn ssh -t user1@xxx.xxx.x.xx
expect  {
        timeout {puts TIMEOUT}
        "yes/no" {send "yes\r";exp_continue}
        "password:" {send "user1password\r";exp_continue}
        -re $prompt
}
send "su - root\r"
expect "Password:"
send "rootpassword\r"
expect -re $prompt
send "whoami\r"
expect -re $prompt

# and to exit
send "exit\r"      ;# exit su
expect -re $prompt
send "exit\r"      ;# exit ssh
expect eof