在哈希表中展开属性

Question

我遇到一个简单的脚本问题,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相结合,因此GCI失败.

该脚本从两列.csv中读取条目,标题是"server"和"platform"

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,条目$_.Server应该是SERVER1,SERVER2,SERVER3等,来自servers.csv中的所有条目,而不是两者的值$_.Server和$_.Platform组合.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命令有效？

Answer 1

PowerShell只在字符串中进行简单的变量扩展.对于更复杂的表达式,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,并保持操作的其余部分不变.

示范:

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

为避免这种情况,您需要:

• 首先将结果值赋给变量并在字符串中使用该变量:

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

• 使用子表达式($(...)):

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

• 使用格式operator(-f):

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