本文重点解决两个问题：

1. 获取SSH远程执行命令的返回状态
2. expect执行SSH时进程中不显示密码明文

先上Shell 代码：

export IP CMD SSH_PWDexpect << 'END'# 关闭输出log_user 0set timeout 30# 从系统变量获取数据set ip "$env(IP)"set cmd "$env(CMD)"set pwd "$env(SSH_PWD)"spawn ssh root@$ip "$cmd"expect {    "(yes/no)?"                           {send "yes\r";exp_continue}    # 忽略大小写    -nocase "password:"                   {send "$pwd\r";exp_continue}    # 登录成功，打开输出    -nocase "authentication successful"   {log_user 1;exp_continue}    # 登录失败    -nocase "authentication fail"         {exit 222}    -nocase "permission denied"           {exit 222}    eof}puts $expect_out(buffer)lassign [wait] pid spawnid os_error_flag value# 系统错误if {$os_error_flag == -1} {    puts "os errno: $value"} else {    # 返回 CMD 执行结果    exit $value}ENDexitCode=$?if [ $exitCode -eq 222 ]; then    echo 'log error'elif [ $exitCode -ne 0 ]; then    echo 'cmd error'fi

获取执行结果的关键在于【wait】方法的使用：

wait [args]

delays until a spawned process (or the current process if none is named) terminates.

wait normally returns a list of four integers. The first integer is the pid of the process that was waited upon. The second integer is the corresponding spawn id. The third integer is -1 if an operating system error occurred, or 0 otherwise. If the third integer was 0, the fourth integer is the status returned by the spawned process. If the third integer was -1, the fourth integer is the value of errno set by the operating system. The global variable errorCode is also set.

【wait】：延迟直到一个spawn进程结束。返回4个数值：

1. expect 进程 pid
2. spawn 线程 id
3. OS状态值（-1：系统错误，0：正常）
4. spawn命令返回值（OS值为 -1时返回OS错误代码，为 0时返回CMD退出值）

参考：、

开头的两个问题都得到了解决：

• 使用 wait 获取SSH 远程执行命令的返回状态，登录失败也可以通过指定状态码（222）标识；
• 使用 env 读取外部变量到expect 变量中，从而 PS 不会显示 密码明文。