我需要测试两个包含路径的字符串，以确定它们是否指向相同的目录。
简单地使用字符串比较会导致比较失败，例如比较 C:\Windows 和 C:\Windows\。
可以按照这个 StackOverflow 问题中提到的方法使用 Join-Path 来解决此问题，但是仍然有其他问题：
例如，\\server\share 有时可以表示为 UNC\server\share 或 \\<ip>\share。
有没有一个适当的方式来检查它，而不必使用变通方法？
编辑：
我已经在我的 PowerShell 模块 PSHelperTools 中实现了找到的代码，可以使用 Install-Module PSHelperTools 下载。
目前我正在使用这个方法作为解决办法：
function Format-Path(){
[Cmdletbinding()]
param($Path)
Write-Verbose "Format-Path: $Path"
if($Path.StartsWith(".")){
#Get Absolute path if path starts with "."
$Path = Resolve-Path -Path $Path
Write-Verbose "Resolved Path: $Path"
}
if($Path -match "^.*::(.*)"){
$Path = $Path -replace "^.*::(.*)", '$1'
Write-Verbose "Replaced Powershell providers: $Path"
}
$Path = $Path -replace "/" , "\" `
-replace "^\\\\\.\\" , "" `
-replace "^\\\\\?\\" , "" `
-replace "^UNC\\" , "\\"
Write-Verbose "Replaced UNC conventions: $Path"
if($Path -match "^\\\\([A-Za-z]+)(@SSL)?"){
$Path = $Path -replace "^\\\\([A-Za-z]+)(@SSL)?", "\\$((Resolve-DnsName $matches[1] -Type "A").IPAddress)"
Write-Verbose "Resolve name into IP: $Path"
}
return $Path.TrimEnd("\")
}
有一种正确的方法可以做到这一点，就像您在这个混乱中看到的https://dev59.com/7nRB5IYBdhLWcg3w1Kn0#74201349
以下是其中任何答案都不完全可接受的原因：
出于以下原因，我列出了每种方法的预期结果列表，如下所示：
function tests {
context "cwd" {
it 'has no external libraries' {
Load-NormalizedPath
}
it 'barely work for FileInfos on existing paths' {
Get-NormalizedPath 'a\..\c' | should -be 'c'
}
it 'process .. and . (relative paths)' {
Get-NormalizedPath 'a\b\..\..\c\.' | should -be 'c'
}
it 'must support powershell providers' {
Get-NormalizedPath "FileSystem::\\$env:COMPUTERNAME\Shared\a\..\c" | should -be "FileSystem::\\$env:COMPUTERNAME\Shared\c"
}
it 'must support powershell drives' {
Get-NormalizedPath 'HKLM:\Software\Classes\.exe\..\.dll' | should -be 'HKLM:\Software\Classes\.dll'
}
it 'works with non-existant paths' {
Get-NormalizedPath 'fred\frog\..\frag\.' | should -be 'fred\frag'
}
it 'works with non-existant drives' {
Get-NormalizedPath 'U:\fred\frog\..\frag\.' | should -be 'U:\fred\frag'
}
it 'barely work for direct UNCs' {
Get-NormalizedPath "\\$env:COMPUTERNAME\Shared\a\..\c" | should -be "\\$env:COMPUTERNAME\Shared\c"
}
}
context "reroot" {
it 'doesn''t reroot subdir' {
Get-NormalizedPath 'fred\frog\..\frag\.' | should -be 'fred\frag'
}
it 'doesn''t reroot local' {
Get-NormalizedPath '.\fred\frog\..\frag\.' | should -be 'fred\frag'
}
it 'doesn''t reroot parent' {
Get-NormalizedPath "..\$((Get-Item .).Name)\fred\frog\..\frag\." | should -be 'fred\frag'
}
}
context "drive root" {
beforeEach { Push-Location 'c:/' }
it 'works on drive root' {
Get-NormalizedPath 'fred\frog\..\..\fred\frag\' | should -be 'fred\frag\'
}
afterEach { Pop-Location }
}
context "temp drive" {
beforeEach { New-PSDrive -Name temp -PSProvider FileSystem 'b:/tools' }
it 'works on temp drive' {
Get-NormalizedPath 'fred\frog\..\..\fred\frag\' | should -be 'fred\frag\'
}
it 'works on temp drive with absolute path' {
Get-NormalizedPath 'temp:\fred\frog\..\..\fred\frag\' | should -be 'temp:\fred\frag\'
}
afterEach { Remove-PSDrive -Name temp }
}
context "unc drive" {
beforeEach { Push-Location "FileSystem::\\$env:COMPUTERNAME\Shared\" }
it 'works on unc drive' {
Get-NormalizedPath 'fred\frog\..\..\fred\frag\' | should -be 'fred\frag\'
}
afterEach { Pop-Location }
}
}
正确的答案使用 GetUnresolvedProviderPathFromPSPath，但是它不能单独工作，如果您尝试直接使用它，您将得到这些结果。
来自这个答案 https://dev59.com/7nRB5IYBdhLWcg3w1Kn0#52157943。
$path = Join-Path '/' $path
$path = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($path)
$path = $path.Replace($pwd.Path, '').Replace($pwd.Drive.Root, '')
pros: simple
cons: needs boilerplate to make it correct, doesn't work with other providers or non-ex drives.
Context cwd
[+] has no external libraries 4ms (1ms|3ms)
[+] barely work for FileInfos on existing paths 3ms (2ms|0ms)
[+] process .. and . (relative paths) 3ms (2ms|0ms)
[-] must support powershell providers 4ms (3ms|1ms)
Expected: 'FileSystem::\\LUIZMONAD\Shared\c'
But was: '\\LUIZMONAD\Shared\a\..\c'
^
[-] must support powershell drives 14ms (4ms|10ms)
Expected: 'HKLM:\Software\Classes\.dll'
But was: 'Cannot find drive. A drive with the name '\HKLM' does not exist.'
^
[+] works with non-existant paths 3ms (2ms|1ms)
[-] works with non-existant drives 4ms (3ms|1ms)
Expected: 'U:\fred\frag'
But was: 'Cannot find drive. A drive with the name '\U' does not exist.'
^
[-] barely work for direct UNCs 3ms (3ms|1ms)
Expected: '\\LUIZMONAD\Shared\c'
But was: '\\LUIZMONAD\Shared\a\..\c'
-------------------^
Context reroot
[+] doesn't reroot subdir 3ms (2ms|1ms)
[+] doesn't reroot local 33ms (33ms|1ms)
[-] doesn't reroot parent 4ms (3ms|1ms)
Expected: 'fred\frag'
But was: '\fred\frag'
^
Context drive root
[+] works on drive root 5ms (3ms|2ms)
Context temp drive
[+] works on temp drive 4ms (3ms|1ms)
[-] works on temp drive with absolute path 6ms (5ms|1ms)
Expected: 'temp:\fred\frag\'
But was: 'Cannot find drive. A drive with the name '\temp' does not exist.'
^
Context unc drive
[+] works on unc drive 6ms (5ms|1ms)
Tests completed in 207ms
Tests Passed: 9, Failed: 6, Skipped: 0 NotRun: 0
GetUnresolvedProviderPathFromPSPath，最后再把驱动程序/提供程序/UNC放回去。
不幸的是，GetUPPFP依赖于当前的pwd状态，但至少我们没有改变它。$path_drive = [ref] $null
$path_abs = $ExecutionContext.SessionState.Path.IsPSAbsolute($path, $path_drive)
$path_prov = $ExecutionContext.SessionState.Path.IsProviderQualified($path)
# we split the drive away, it makes UnresolvedPath fail on non-existing drives.
$norm_path = Split-Path $path -NoQualifier
# strip out UNC
$path_direct = $norm_path.StartsWith('//') -or $norm_path.StartsWith('\\')
if ($path_direct) {
$norm_path = $norm_path.Substring(2)
}
# then normalize
$norm_path = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($norm_path)
# then we cut out the current location if same drive
if (($path_drive.Value -eq $pwd.Drive.Name) -or $path_direct) {
$norm_path = $norm_path.Substring($pwd.Path.Trim('/', '\').Length + 1)
} elseif (-not $path_prov) {
# or we cut out the current drive
if ($pwd.Drive) {
$norm_path = $norm_path.Substring($pwd.Drive.Root.Length)
} else {
# or we cut out the UNC special case
$norm_path = $norm_path.Substring($pwd.ProviderPath.Length + 1)
}
}
# then add back the UNC if any
if ($path_direct) {
$norm_path = $pwd.Provider.ItemSeparator + $pwd.Provider.ItemSeparator + $norm_path
}
# then add back the provider if any
if ($path_prov) {
$norm_path = $ExecutionContext.SessionState.Path.Combine($path_drive.Value + '::/', $norm_path)
}
# or add back the drive if any
elseif ($path_abs) {
$norm_path = $ExecutionContext.SessionState.Path.Combine($path_drive.Value + ':', $norm_path)
}
$norm_path
pros: doesn't use the dotnet path function, uses proper powershell infrastructure.
cons: kind of complex, depends on `pwd`
Context cwd
[+] has no external libraries 8ms (2ms|6ms)
[+] barely work for FileInfos on existing paths 4ms (3ms|1ms)
[+] process .. and . (relative paths) 3ms (2ms|1ms)
[+] must support powershell providers 13ms (13ms|0ms)
[+] must support powershell drives 3ms (2ms|1ms)
[+] works with non-existant paths 3ms (2ms|0ms)
[+] works with non-existant drives 3ms (2ms|1ms)
[+] barely work for direct UNCs 3ms (2ms|1ms)
Context reroot
[+] doesn't reroot subdir 3ms (2ms|1ms)
[+] doesn't reroot local 3ms (2ms|1ms)
[+] doesn't reroot parent 15ms (14ms|1ms)
Context drive root
[+] works on drive root 4ms (3ms|1ms)
Context temp drive
[+] works on temp drive 4ms (3ms|1ms)
[+] works on temp drive with absolute path 3ms (3ms|1ms)
Context unc drive
[+] works on unc drive 9ms (8ms|1ms)
Tests completed in 171ms
Tests Passed: 15, Failed: 0, Skipped: 0 NotRun: 0
源代码与测试： https://gist.github.com/Luiz-Monad/d5aea290087a89c070da6eec84b33742#file-normalize-path-ps-md
UNC\server\share不是 UNC 路径，它只是一个相对本地路径。你是不是想说\\.\UNC\server\share？ - Mathias R. Jessen\\?\UNC\server\share？ - Theo((Get-Item $path | Select-Object -ExpandProperty Target) -replace "^UNC\\","\\")手动删除了 UNC，并且手动没有在路径末尾添加反斜杠。我知道这是可能的，这不是我的问题。我的问题是是否有一种正确的方法可以使用官方 cmdlet 来实现。 - Kevin Holtkamp