arrays - 扩展哈希表中的属性

Question

我的脚本遇到了一个简单的问题，我想在远程服务器上运行 GCI，问题是，该值与另一个哈希表属性组合在一起，因此 GCI 失败。

该脚本从两列 .csv 中读取条目，标题为“服务器”和“平台”

这是我得到的:

$ShortDate = (Get-Date).ToString('MM/dd/yyyy')
$CheckServer = @{}
$serverObjects = @() # create a list of server objects

Import-Csv $Dir\Servers.csv | ForEach {  
    $CheckServer.Server = $_.Server
    $CheckServer.Platform = $_.Platform

    if (GCI \\$_.Server\c$\log\Completed_Summary_*.html -EA 0 | where {$.LastWriteTime -ge "$ShortDate"}) {
        Write-Host "FOUND"
    } # end of IF GCI
} # end of For-Each

$serverObjects += New-Object -TypeName PSObject -Property $CheckServer

问题是 $_.Server 的条目应该是 SERVER1、SERVER2、SERVER3 等，即servers.csv 中的所有条目，而不是 $ 的值_.Server 和 $_.Platform 组合在一起。如:

Write-Host "Checking" \\@{Server=SERVER1; Platform=PLATFORM_1}.Server\c$\log\Completed_Summary_*.html

它应该显示如下:

Write-Host "Checking" \\SERVER1\log\Completed_Summary_*.html

如何取消组合它们以便 GCI 命令起作用？

Answer 1

PowerShell 仅在字符串内进行简单的变量扩展。对于更复杂的表达式(例如索引操作或访问对象属性/方法)，它将插入数组或对象变量的字符串化值，并保持其余操作不变。

演示:

PS C:\> $array = 23, 42
PS C:\> Write-Host "some $array[1] or other"
some 23 42[1] or other
PS C:\> $object = New-Object -Type PSObject -Property @{Foo=23; Bar=42}
PS C:\> Write-Host "some $object.Foo or other"
some @{Bar=42; Foo=23}.Foo or other

To avoid this you need to either:

• assign the resulting value to a variable first and use that variable in the string:

  $value = $array[5]
  Write-Host "some $value or other"
  
  $value = $object.Foo
  Write-Host "some $value or other"
  

• 使用subexpression ($(...)):

  Write-Host "some $($array[5]) or other"
  Write-Host "some $($object.Foo) or other"
  

• 使用format operator (-f):

  Write-Host "some {0} or other" -f $array[5]
  Write-Host "some {0} or other" -f $object.Foo