查找主 PowerShell 脚本文件的位置（路径）

Question

我正在寻找一种方法来获取主（比如说“入口点”）PowerShell 脚本 (*.ps1) 文件的路径。

让我们以下面的例子为例：

• 我有以下文件：

“C:\MyDir1\Main.ps1”调用中的函数

"C:\MyDir2\SubDir1\MyModule.psm1" 中调用函数

“C:\AnotherDir\AnotherScript.ps1”

• 我运行以下 PowerShell 命令：

"PowerShell.exe -File "C:\MyDir1\Main.ps1"

• 我想要什么：从脚本“AnotherScript.ps1”中，我想找到“C:\MyDir1\Main.ps1”的路径。

注意 1： 请注意，我不是在谈论可通过 $PSScriptRoot 变量获得的当前脚本的路径。

注意 2： 看来变量 $global:PSScriptRoot（与 $PSScriptRoot 不同) 是我正在寻找的，但不幸的是，当从 PowerShell 会话调用主脚本时，此值为空。

Answer 1

这是一个可以完成这项工作的函数，但它非常棘手（可能太多了）。

function Get-EntryPointAbsFilePath() {

    # NOTE 1: Do not use '$MyInvocation.PSScriptRoot' because it corresponds to the path of the calling script (not entry point script).
    # NOTE 2: '$global:PSScriptRoot' is not the same as '$PSScriptRoot' and seems to correspond to the entry point script directory,
    # but it is set only when the main script is invoked from powershell command like [PowerShell.exe -File "MainScript.ps1"] but not
    # when "MainScript.ps1" is invoked from a PowerShell session (prompt) like [PS C:\Temp>. MainScript.ps1].
    $CallStack = Get-PSCallStack

    # We take the last stack element (correponding to the first call).
    # The 'ScriptName' property of this first call can be null when the main script is invoked from a PowerShell session like [PS C:\Temp>. MainScript.ps1].
    # This is because PowerShell first evaluates the entered command.
    $FirstCall = $CallStack[$CallStack.Count - 1];
    if ($null -ne $FirstCall.ScriptName) {
        return $FirstCall.ScriptName;
    }

    # We take the second call (assuming that we are run under a PowerShell session).
    # To make sure this call is coming from the execution of a script file (and not from the execution a cmdlet in the interpreter, like a function in a module),
    # we check the 'FunctionName' property which equals "<ScriptBlock>" when a call is performed from a script block, like a ps1 file.
    # This test is not required for the first call, as a PowerShell module can't be run.
    $SecondCall = $CallStack[$CallStack.Count - 2];
    if ($null -ne $SecondCall.ScriptName -and $SecondCall.FunctionName -eq "<ScriptBlock>") {
        return $SecondCall.ScriptName;
    }

    throw "No PowerShell entry point script could be found. This cmdlet ""$($MyInvocation.MyCommand.Name)"" is intended to be called only via the execution of a script file.";
}