function - 如何在 Powershell 脚本中创建函数？

Question

如何编写一个函数来避免我的 powershell 脚本的重复代码，它基本上从控制面板中的添加和删除窗口显示安装在我的机器上的应用程序列表。

下面是powershell脚本

堆栈.ps1

Clear-Host

#$scriptPath = split-path -parent $MyInvocation.MyCommand.Definition
$scriptPath = $PSScriptRoot
$logFilePath= Join-path $scriptPath "TestResults.log"

#If log file exists, then clear its contents 
if (Test-Path $logFilePath)
{
    clear-content -Path $logFilePath
} 


$log = "Date Of Testing: {0} " -f (Get-Date)
$logString = "Process Started." 
add-content -Path $logFilePath -Value $log -Force 
add-content -Path $logFilePath -Value $logString -Force 
add-content -Path $logFilePath -Value "`n" -Force


#Validate ADD/Remove Program list

add-content -Path $logFilePath -Value "`n" -Force
add-content -Path $logFilePath -Value "Add/Remove Programs :" -Force
add-content -Path $logFilePath -Value "`n" -Force

  $InstalledPrograms = Get-ItemProperty HKLM:\Software\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\*

add-content -Path $logFilePath -Value "`n" -Force
foreach ($InstalledProgram in $InstalledPrograms )
{
   if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("Operational Control")))
    {
        $InstalledProgram |  Select-Object DisplayName, DisplayVersion, Publisher, InstallDate | 
        Format-Table –AutoSize

        $logString = $InstalledProgram.DisplayName 
        $logp = $InstalledProgram.Publisher
        $logv = $InstalledProgram.DisplayVersion
        $logd= $InstalledProgram.InstallDate

        add-content -Path $logFilePath -Value "Product Name: $logString" -Force   
        add-content -Path $logFilePath -Value "Publisher: $logp" -Force  
        add-content -Path $logFilePath -Value "Version: $logv" -Force  
        add-content -Path $logFilePath -Value "InstallDate: $logd" -Force  
        add-content -Path $logFilePath -Value "`n" -Force****

    }

if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("Management Studio")))
    {
        $InstalledProgram |  Select-Object DisplayName, DisplayVersion, Publisher, InstallDate | 
        Format-Table –AutoSize

        $logString = $InstalledProgram.DisplayName 
        $logp = $InstalledProgram.Publisher
        $logv = $InstalledProgram.DisplayVersion
        $logd= $InstalledProgram.InstallDate

        add-content -Path $logFilePath -Value "Product Name: $logString" -Force   
        add-content -Path $logFilePath -Value "Publisher: $logp" -Force  
        add-content -Path $logFilePath -Value "Version: $logv" -Force  
        add-content -Path $logFilePath -Value "InstallDate: $logd" -Force  
        add-content -Path $logFilePath -Value "`n" -Force

    }

    if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("System Analyzer")))
    {
        $InstalledProgram |  Select-Object DisplayName, DisplayVersion, Publisher, InstallDate | 
        Format-Table –AutoSize

        $logString = $InstalledProgram.DisplayName 
        $logp = $InstalledProgram.Publisher
        $logv = $InstalledProgram.DisplayVersion
        $logd= $InstalledProgram.InstallDate

        add-content -Path $logFilePath -Value "Product Name: $logString" -Force   
        add-content -Path $logFilePath -Value "Publisher: $logp" -Force  
        add-content -Path $logFilePath -Value "Version: $logv" -Force  
        add-content -Path $logFilePath -Value "InstallDate: $logd" -Force  
        add-content -Path $logFilePath -Value "`n" -Force

    }

      if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("STeP")))
    {
        $InstalledProgram |  Select-Object DisplayName, DisplayVersion, Publisher, InstallDate | 
        Format-Table –AutoSize

        $logString = $InstalledProgram.DisplayName 
        $logv = $InstalledProgram.DisplayVersion
        $logd= $InstalledProgram.InstallDate

        add-content -Path $logFilePath -Value "Product Name: $logString" -Force   
        add-content -Path $logFilePath -Value "Version: $logv" -Force  
        add-content -Path $logFilePath -Value "InstallDate: $logd" -Force  
        add-content -Path $logFilePath -Value "`n" -Force

    }   
}

我说的是每个 if 语句下的代码，用于将输出复制到日志文件。我可以用函数替换该代码并在每个 if 语句中调用该函数吗？

Answer 1

好的，让我们这样做。函数是关于避免重复代码，这里可以在多个级别上完成。 PowerShell 中的函数在执行之前需要声明，所以我倾向于将所有函数聚集在脚本的开头，如下所示:

# *** FUNCTION DEFINITIONS

function Log-InstalledProgram($InstalledProgram, $LogFilePath)
{
    $InstalledProgram |  Select-Object DisplayName, DisplayVersion, Publisher, InstallDate | 
    Format-Table –AutoSize

    $logString = $InstalledProgram.DisplayName 
    $logp = $InstalledProgram.Publisher
    $logv = $InstalledProgram.DisplayVersion
    $logd= $InstalledProgram.InstallDate

    add-content -Path $LogFilePath -Value "Product Name: $logString" -Force   
    add-content -Path $LogFilePath -Value "Publisher: $logp" -Force  
    add-content -Path $LogFilePath -Value "Version: $logv" -Force  
    add-content -Path $LogFilePath -Value "InstallDate: $logd" -Force  
    add-content -Path $LogFilePath -Value "`n" -Force
}

# *** BEGIN MAIN SCRIPT

Clear-Host

#$scriptPath = split-path -parent $MyInvocation.MyCommand.Definition
$scriptPath = $PSScriptRoot
$logFilePath= Join-path $scriptPath "TestResults.log"

#If log file exists, then clear its contents 
if (Test-Path $logFilePath)
{
    clear-content -Path $logFilePath
} 


$log = "Date Of Testing: {0} " -f (Get-Date)
$logString = "Process Started." 
add-content -Path $logFilePath -Value $log -Force 
add-content -Path $logFilePath -Value $logString -Force 
add-content -Path $logFilePath -Value "`n" -Force


#Validate ADD/Remove Program list

add-content -Path $logFilePath -Value "`n" -Force
add-content -Path $logFilePath -Value "Add/Remove Programs :" -Force
add-content -Path $logFilePath -Value "`n" -Force

  $InstalledPrograms = Get-ItemProperty HKLM:\Software\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\*

add-content -Path $logFilePath -Value "`n" -Force

foreach ($InstalledProgram in $InstalledPrograms )
{
   if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("Operational Control")))
    {
        Log-InstalledProgram $InstalledProgram $logFilePath
    }

    if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("Management Studio")))
    {
        Log-InstalledProgram $InstalledProgram $logFilePath
    }

    if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("System Analyzer")))
    {
        Log-InstalledProgram $InstalledProgram $logFilePath
    }

    if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains("STeP")))
    {
        Log-InstalledProgram $InstalledProgram $logFilePath
    }   
}

您可以通过为所需程序添加内部循环来进一步减少代码:

foreach ($InstalledProgram in $InstalledPrograms )
{
    foreach ($displayName in "Operational Control","Management Studio", "System Analyzer", "STeP")
    {
        if(($InstalledProgram.DisplayName -ne $Null) -and ($InstalledProgram.DisplayName.Contains($displayName)))
        {
            Log-InstalledProgram $InstalledProgram $logFilePath
        }
    }
}

还有其他优化，例如您可以避免重复调用 Add-Content因为 -Value参数也接受一个数组作为参数，您可以使用哈希表来捕获要提取的对象属性及其在日志文件中的显示名称等。