为什么Write-Host"$ PSCommandPath"不输出我当前的路径？

Question

我有以下一点代码 -

Set-Location "$PSCommandPath"
Write-Host "Starting script."
Write-Host "Current directory is... $PSCommandPath"

这只是返回 -

Starting script.
Current directory is...

我该如何解决这个问题？

Answer 1

如果我不得不猜测,您运行的是不支持的旧版PowerShell $PSCommandPath.该变量仅适用于3.0及更高版本.从文档:

$PSCommandPath

包含正在运行的脚本的完整路径和名称.此参数在所有脚本中都有效.Windows PowerShell 3.0中引入了此自动变量.

因此,像所有未定义的变量一样,$PSCommandPath被视为$null:

PS > ($undefined).GetType()
You cannot call a method on a null-valued expression.
At line:1 char:1
+ ($undefined).GetType()
+ ~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull


PS > 
PS > $var = 123
PS > Write-Host "My variable: $var"
My variable: 123

PS > Write-Host "My variable: $undefined"
My variable: 

PS > 

要解决此问题,您需要将PowerShell升级到3.0或更高版本.

此外,它似乎你真的想要Get-Location,它返回当前的工作目录:

Write-Host "Current directory is... $(Get-Location)"