为什么此PowerShell脚本会产生错误？

Question

我有一个目录中调用Eric Clapton - Nothing But The Blues - Full Concert (1994) [HQ].URL的文件C:\Hans\Hans4\.

创建此代码的代码如下(尽管无论文件内容如何都会发生错误)

$fileContents = @"
[{000214A0-0000-0000-C000-000000000046}]
Prop3=19,2
[InternetShortcut]
URL=http://example.com/
IDList=
"@

New-Item -Path "C:\Hans\Hans4" `
         -Name "Eric Clapton - Nothing But The Blues - Full Concert (1994) [HQ].URL" `
         -ItemType "file" `
         -Value $fileContents `
         -Force

当我运行以下内容时出现错误

Get-ChildItem 'C:\Hans' -Recurse | Resolve-ShortcutFile > Output.txt

代码引用了下面的函数

function Resolve-ShortcutFile {         
    param(
        [Parameter(
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position = 0)]
        [Alias("FullName")]
        [string]$fileName
    )
    process {
        if ($fileName -like "*.url") {
            Get-Content $fileName | Where-Object {
                $_ -like "url=*"
            } |
            Select-Object @{
                Name='ShortcutFile'
                Expression = {Get-Item $fileName}
            }, @{
                Name='Url'
                Expression = {$_.Substring($_.IndexOf("=") + 1 )}
            } 
        }
    }
}

这是错误消息

Get-Content : An object at the specified path C:\Hans\Hans4\Eric Clapton - Nothing But 
The Blues - Full Concert (1994) [HQ].URL does not exist, or has been filtered by 
the -Include or -Exclude parameter.
At line:33 char:28
+             Get-Content $fileName | Where-Object {
+             ~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (System.String[]:String[]) [Get-Content], Exception
    + FullyQualifiedErrorId : ItemNotFound,Microsoft.PowerShell.Commands.GetContentCommand

为什么我会收到此错误？

Answer 1

问题是通过管道输入函数并传递给的文件名 Get-Content

C:\ Hans\Hans4\Eric Clapton - Nothing but the Blues - Full Concert(1994)[HQ] .URL

您遇到了此处描述的问题.

它包含方括号,它们被解释为具有集合H和Q的范围运算符

因此,模式意味着它尝试使用以下任一名称读取文件的内容......

• Eric Clapton - Nothing But The Blues - Full Concert(1994)H .URL
• Eric Clapton - Nothing But The Blues - Full Concert(1994)Q .URL

......但不会匹配文本[HQ]中

• Eric Clapton - Nothing But The Blues - Full Concert(1994)[HQ] .URL

您可以使用该-literalPath参数来避免此问题并按字面处理文件名.

function Resolve-ShortcutFile {         
    param(
        [Parameter(
            ValueFromPipeline=$true,
            ValueFromPipelineByPropertyName=$true,
            Position = 0)]
        [Alias("FullName")]
        [string]$fileName
    )
    process {
        if ($fileName -like "*.url") {
            Get-Content  -literalPath $fileName | Where-Object {
                $_ -like "url=*"
            } |
            Select-Object @{
                Name='ShortcutFile'
                Expression = {Get-Item  -literalPath $fileName}
            }, @{
                Name='Url'
                Expression = {$_.Substring($_.IndexOf("=") + 1 )}
            } 
        }
    }
}