使用函数中的值并将其传递给另一个函数

Question

我有以下两个函数，我希望在比较函数中使用ROBOCOPY函数的源和目标。有人能告诉我怎么做吗？谢谢。

Write-Host "==================================" -ForegroundColor Magenta -BackgroundColor White
Write-Host "Pre-Staging Script for DFSR Server" -ForegroundColor Magenta -BackgroundColor White
Write-Host "==================================" -ForegroundColor Magenta -BackgroundColor White
Write-Host ""
Function GetHot-Fix
{
                Write-Host "==================================" -ForegroundColor Magenta -BackgroundColor White
                Write-Host "Checking Service Installation" -ForegroundColor Magenta -BackgroundColor White
                Write-Host "==================================" -ForegroundColor Magenta -BackgroundColor White
                Write-Host ""
                write-host "This will check if Hotfix KB979808 is installed." -ForegroundColor Black -BackgroundColor Cyan
                write-host "This is required for Windows Server 2008 R2 Robocopying"  -ForegroundColor Black -BackgroundColor Cyan
                Write-Host ""

                Get-HotFix -id KB979808 -ErrorAction SilentlyContinue

}

Function Start-MyRobocopy($source,$Target)
{
                Write-Host "=============" -ForegroundColor Magenta -BackgroundColor White
                Write-Host "Robocopy Data" -ForegroundColor Magenta -BackgroundColor White
                Write-Host "=============" -ForegroundColor Magenta -BackgroundColor White
                Write-Host ""

                $Source = Read-Host "Please enter path of SOURCE"

                If ($Source -and (Test-Path -Path $Source -PathType Container))
                {
                                $Target = Read-Host "Please enter path of TARGET"
                }
                Else
                {
                Write-Host "Please enter a directory"
                }
                                If ($Target -and (Test-Path -Path $Target -PathType Container))
                                {
                                $Output = Read-Host "Please enter where to place output file eg c:\temp\COPY.log"
                                }
                                Else
                                {
                                Write-Host "Please enter a directory"
                                }


robocopy.exe $Source $Target /b /e /copyall /r:1 /xd dfsrprivate /log:$Output /tee
}
Function Comparision
{
                Write-Host ""
                Write-Host ""     
                Write-Host "===============================================" -ForegroundColor Magenta -BackgroundColor White
                Write-Host "Checking Directory Count and Folder comparision" -ErrorAction SilentlyContinue -ForegroundColor Magenta -BackgroundColor White
                Write-Host "===============================================" -ForegroundColor Magenta -BackgroundColor White
                Write-Host ""

             #$Source = Read-Host "Please enter Source directory to check"
             #$Target = Read-Host "Please enter Target directory to check"
                Write-Host ""
                If($source -and (Test-Path -Path $source -PathType Container))
                {
                "There are $(@(Get-ChildItem $Source).Count) items in the '$Source' directory"  
                }
                Else
                {
                Write-Host "Please enter a directory"
                                }
                                If($source -and (Test-Path -Path $Target -PathType Container))
                                {
                                "There are $(@(Get-ChildItem $Target).Count) items in the '$Target' directory"  
                }
                Else
                {
                Write-Host "Please enter a directory"
                }

                Write-Host ""
                $child1 = Get-ChildItem -Path $Source -Recurse -Force
                $child2 = Get-ChildItem -Path $Target -Recurse -Force

                Compare-Object $child1 -DifferenceObject $child2 -Property Name

                Write-Host ""
                Write-Host "NOTE:" -BackgroundColor Cyan -ForegroundColor Black
                Write-Host "Any symbols with '=>' mean that the file Does NOT exist in SOURCE but is in the Target" -BackgroundColor Cyan -ForegroundColor Black
                Write-Host "Any symbols with '<=' mean that the file Does NOT exist in TARGET but is in the Source" -BackgroundColor Cyan -ForegroundColor Black
}


$hotfix = GetHot-Fix
If ($hotfix) {
                Write-Host "Hotfix installed" -BackgroundColor Green -ForegroundColor Black
                Write-Host ""
                Write-Host "Proceeding with Robocopy...."
                Write-Host "............................"
                Write-Host ""
                Start-MyRobocopy
                }
else {
                                Write-Host "Hotfix is NOT installed - Please ensure you install this hotfix BEFORE" -ForegroundColor "red"
        Write-host "Copying any data" -foregroundcolor "red"
                                Write-Host ""
                                return
                }

Comparision

Answer 1

powershell中的变量是上下文相关的。如果我定义如下函数：

$bar = "Hi"
function foo {
   $bar = "Hey!"
}
$bar <-- returns "Hi"

那么在该函数之外，我就不能使用$bar变量。要使变量在函数之外可用，则可以控制函数的作用域。如果我使用脚本或全局前缀在函数中设置一个变量，那么该变量将可用于整个脚本或powershell运行空间中的全局。请看这里：

function foo {
   $script:fooVar = "world"
}

function bar {
   foo
   $global:barVar = "Hello " + $fooVar
}

由于变量$fooVar的作用域前缀script，foo函数中的变量$fooVar将可用于脚本中的所有其他函数。barVar函数将在运行空间中全局可用。也就是说，当你的脚本结束时，变量仍然存在于命令行甚至其他脚本中。

正如您在bar函数中看到的，我首先调用foo，然后使用foovVar变量。当我使用$fooVar变量时，我不需要指定$script:fooVar，如果我想的话，我可以这样做，但这不是必须的。

这些都是有效的变量赋值：

$aaa = 123
$script:bbb = 123
$global:ccc = 123 

因此，在您的示例中，使用$script:source和$script:target或$global:source和$global:target。有关详细信息，请运行以下命令：

Help About_Scope

Answer 2

粗俗的方法是将以下内容添加到顶部：

$Gobal:source = ""
$Gobal:target = ""

用$Gobal:source搜索并替换$source，用$Gobal:target替换$target --这样您就可以在脚本中的任何地方使用这些新的全局变量。

正如所建议的，你可以在另一个函数中保护它们，但对于一个简单的作业\自动化任务来说，这可能是过度杀伤力。这要看它是用来做什么的。

Answer 3

你有几个选择。其中两个是全局状态(在文件范围内声明了$source和$target，两个函数都使用它们)，并将它们作为参数进行比较。假设您的robocopy函数询问用户源和目标是否为null，那么全局状态是最简单的解决方案。就我个人而言，我可能会编写第三个函数，名为Get-SourceAndTarget，它处理这一部分并输出源和目标，这样您就可以将它们传递给Start-MyRobocopy和Comparison。我对powershell的理解不是很好，所以我对语法有点不清楚，但这可能会让你入门。