Powershell - 如何在 Powershell 脚本中以非交互方式调用 cmdlet？

Question

In my powershell script, I am calling a cmdlet (Say "Connect-Database"). If the cmdlet needs additional parameter, it prompts the user to supply those values ( say, "Connect-Database" can not get credentials from registry, so it prompts for "Username" "password" on Powershell console and expects the user to give that value ).

I looked into the code of Powershell cmdlet. I found that it is using "CommandInvocationIntrinsics" to prompt the user (using "NewScriptBlock" and then "Invoke" method of "CommandInvocationIntrinsics" ).

Since I am calling this cmdlets from the Powershell script, I want that whenever such a prompting happened, it will be suppressed and an exception is thrown.

The code is something like this -

try
{
    $db = Connect-Database <databasename>
    #if username / password is prompted, it should be converted into error. But it should not be shown in powershell console.

    if($Error.Count > 0)
    {
        throw $Error[0]
    }
}
catch
{
    #do something
}

Answer 1

My way of doing that, is first to enumerate mandatory parameters, and then initialized them with $null vars. So there is no more interaction and an error is thrown.

Answer 2

Easy solution, don't prompt. I feel that you should either always prompt (by using mandatory parameters), or never prompt during the execution of your command. If you don't have enough information, throw an error. If your command is being used interactively, the user can rerun with the correct information.

Answer 3

This is a part of the design of PowerShell and likely cannot be overcome.

If you are trying to be non-interactive, you should be ensuring that you have collected all the necessary information before trying to call the cmdlet (aka, you should not have missing parameters for your non-interactive calls). You are likely following an anti-pattern and should re-think your approach. Prompting at the beginning of your non-interactive script (aka, short startup interaction), having parameters for your non-interactive script (those will, in turn, prompt if missing when set to mandatory), or reading from a config file (and verifying the information first) are a few approaches. Something common you will notice is that they all involve failing fast / failing early , a very good design.