Powershell: Creating symbolic links or junctions with New-Item doesn't work if target contains '[' or ']'

[ky7749]

Steps to reproduce

1. Type on an NTFS/ReFS file system:

New-Item -Path '[target]' -ItemType Directory

1. Try creating a junction (or symbolic link, substitute with 'SymbolicLink' in the -ItemType parameter)

New-Item -Path '[source]' -Value '[target]' -ItemType Junction

Expected behavior

The junction should be created even if the target path contains square bracket characters

Actual behavior

An error message is resulted:

new-item : Cannot find path '[target]' because it does not exist.
At line:1 char:1
+ New-Item -Path '[source]' -Value '[target]' -Itemtype Junction
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidOperation: (:) [New-Item], PSInvalidOperationException
+ FullyQualifiedErrorId : InvalidOperation,Microsoft.PowerShell.Commands.NewItem Command

Note: the command can be made to work with double escapes, but it seems hacky.

new-item -path '[source]' -value "```[target```]" -Itemtype Junction

Environment data

Name                           Value
----                           -----
PSVersion                      6.0.1
PSEdition                      Core
GitCommitId                    v6.0.1
OS                             Microsoft Windows 6.1.7601 S
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

[iSazonov]

It is expected behavior because we support wildcards in paths.

Perhaps we could add -LiteralPath in New-Item

[ky7749]

1. I had the problem with the '-Value' parameter, not '-Path' or even '-LiteralPath'.

2. So perhaps we need '-LiteralValue', not '-LiteralPath'.

[kwkam]

-Name is -LiteralPath
This should work:

New-Item -Name '[target]' -ItemType Directory`
New-Item -Name '[source]' -Value '[target]' -ItemType Junction

[mklement0]

@iSazonov:

To be clear: wildcard support _should not apply_ when _creating new items_.

NewItem's -Path parameter:

• is, on the one hand, commendably already treated as a _literal_ - the new item is created with the specified name as-is.

  • Similarly, -Name is treated literally, but invariably creates the new item in the _current_ location.

  • on the other hand, the parameter _name_ clashes with the use of -Path in cmdlets such as Get-ChildItem, where it implies wildcard support, in contrast with the -LiteralPath parameter;
    New-Item doesn't even _have_ a -LiteralPath parameter (arguably, though, it should be added as an _alias_ of -Path).

Similarly, the -Value parameter - whose alias name is -Target - should _always_ treat a value passed to it as a _literal_, but currently doesn't - and that is the bug.

@kwkam: -Name is _not_ an alias of -LiteralPath, not least because New-Item doesn't even have a -LiteralPath parameter (see above). Aside from that, the inappropriate treatment of a value passed to -Value / -Target as a wildcard expression is the same.

[kwkam]

Okay I forgot I was using a patched(#5896) build.

@mklement0 For consistency with other cmdlet's -Path parameter, and for the convenient with tab completion, I think -Path should stay as is. As for the -Path and -Name, what if we want to do, for example, New-Item -Path '`[path`]/item_[0-9]' -Name '[sub]/dir' -ItemType Directory? -Name can act as -LiteralPath in my opinion.

[mklement0]

@kwkam:

I think -Path should stay as is

I wasn't suggesting that New-Item's -Path be changed, I was suggesting that -LiteralPath be _added as an alias_ for it.

The reason for suggesting that is that -Path _already acts the way -LiteralPath usually does_.

_Conceptually_ speaking, -Name is a path _component_, and, more precisely, the _leaf_ component - it should never accept a _path_.

Unfortunately, it currently _does_ accept a path, namely a _relative_ one: either relative to the path specified in -Path, or, in the latter's absence, relative to the _current_ directory.

Aside from that, -Name doesn't - and shouldn't - accept wildcard patterns either.

For consistency, given that -Path and -Name don't accept wildcard patterns, neither should -Value (a.k.a. -Target).

[Moonsilence]

Similarly, the -Value parameter - whose alias name is -Target - should _always_ treat a value passed to it as a _literal_, but currently doesn't - and that is the bug.

Hey! Googling an Error lead me here. Trying to create a Symlink to a path that contains square brackets using

New-Item -Path C:mypathcover.jpg -ItemType SymbolicLink -Value C:mypath[1995]cover.jpg

"not found"

Has this bug been fixed yet?

[vexx32]

I see a lot of PRs with @kwkam's work but I'm not sure that specific issue has been completely fixed yet.

[anthonypants]

This is definitely still happening in 6.2.0.

[Jessifir]

Running 6.2.2 on Linux and found this issue after hours of scratching my head. In my use case in particular it's important the original file names are preserved.

I tried escaping wildcard characters in the value I pass to -Value/-Target, but that just results in ItemNotFoundException. Re-reading the above, I've found that double-escaping the path first does solve the problem, but that's obviously not something that should be expected of anyone.

What's confusing me the most is from what I read I still don't quite understand why -Value isn't presumable literal. The discussion on the above PR seems much more concerned about -Path and doesn't seem to at all address that -Value should always be literal regardless of how -Path is handled.

[KaXaSA]

So I ran some tests because I was having issues with the [square brackets] inside New-Item ... HardLink -Value here are the results:

[Powershell 7.0.3]

Test 1 | -Value with DOUBLE backticks
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\``[subfolder A``]\file.txt' -Force
[Done] Hardlink created: C:\bfolder001\file.txt
#####

Test 2 | -Value with DOUBLE backticks + SUBFOLDER(B)
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\``[subfolder A``]\subfolder B\file.txt' -Force
[Error] Cannot find path 'C:\bfolder001\``[subfolder A``]\subfolder B\file.txt' because it does not exist.
#####

Test 3 | -Value with SINGLE backticks
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\`[subfolder A`]\file.txt' -Force
[Error] Could not find item C:\bfolder001\`[subfolder A`]\file.txt.
#####

Test 4 | -Value with SINGLE backticks + SUBFOLDER(B)
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\`[subfolder A`]\subfolder B\file.txt' -Force
[Error] Could not find item C:\bfolder001\`[subfolder A`]\subfolder B\file.txt.
#####

Name                           Value
----                           -----
PSVersion                      7.0.3
PSEdition                      Core
GitCommitId                    7.0.3
OS                             Microsoft Windows 10.0.19041
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

[Powershell 5.1]

Test 1 | -Value with DOUBLE backticks
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\``[subfolder A``]\file.txt' -Force
[Done] Hardlink created: C:\bfolder001\file.txt
#####

Test 2 | -Value with DOUBLE backticks + SUBFOLDER(B)
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\``[subfolder A``]\subfolder B\file.txt' -Force
[Error] Cannot find path 'C:\bfolder001\``[subfolder A``]\subfolder B\file.txt' because it does not exist.
#####

Test 3 | -Value with SINGLE backticks
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\`[subfolder A`]\file.txt' -Force
[Done] Hardlink created: C:\bfolder001\file.txt
#####

Test 4 | -Value with SINGLE backticks + SUBFOLDER(B)
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\`[subfolder A`]\subfolder B\file.txt' -Force
[Done] Hardlink created: C:\bfolder001\file.txt
#####

Name                           Value
----                           -----
PSVersion                      5.1.19041.1
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.19041.1
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

---

Can someone explain why in PowerShell 7 the New-Item works in Test 1 but doesn't work in Test 2?

Test 1 | -Value with DOUBLE backticks
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\``[subfolder A``]\file.txt' -Force
[Done] Hardlink created: C:\bfolder001\file.txt
#####

Test 2 | -Value with DOUBLE backticks + SUBFOLDER(B)
Command: New-Item -Path 'C:\bfolder001\file.txt' -ItemType HardLink -Value 'C:\bfolder001\``[subfolder A``]\subfolder B\file.txt' -Force
[Error] Cannot find path 'C:\bfolder001\``[subfolder A``]\subfolder B\file.txt' because it does not exist.
#####

AFAIK the only difference here is the extra subfolder, I changed this:
-Value 'C:\bfolder001\``[subfolder A``]\file.txt'

To:
-Value 'C:\bfolder001\``[subfolder A``]\subfolder B\file.txt'

---

The script if you want to test/check to see if I did something wrong:

$bFolder = 'C:\bfolder001'
$subfA  = '[subfolder A]'
$subfB = 'subfolder B'
$txtFile = 'file.txt'

$backtickS = '`$1'
$backtickD = '``$1'

function Test {
    param (
        [String]$bFolder, [String]$subfA, [String]$subfB, [String]$txtFile, [String]$backtick
    )

    $fullName = "$bFolder\$subfA\$subfB\$txtFile" -replace '\\{2,}', '\' # replace \\ (2 or more) with only one \
    $fullNameEsc = "$fullName" -replace "(\]|\[)", "$backtick" # replace [] with `[`] OR ``[``]
    $hardlinkT = "$bFolder\$txtFile" -replace '\\{2,}', '\'

    Try {
        New-Item -Path $fullName -ItemType File -Force -ErrorAction Stop | out-null

        "Command: New-Item -Path `'$hardlinkT`' -ItemType HardLink -Value `'$fullNameEsc`' -Force" | Write-Host -ForegroundColor Cyan
        New-Item -Path $hardlinkT -ItemType HardLink -Value $fullNameEsc -Force -ErrorAction Stop | out-null
        "[Done] Hardlink created: $bFolder\$txtFile" | Write-Host -ForegroundColor Green
    } Catch {
        "[Error] $_" | Write-Host -ForegroundColor Red
    } Finally {
        if ($bFolder -notmatch "^\w:\\?$") {
            Remove-Item -Path $bFolder -Recurse #-Confirm
        }
        "#####" | Write-Host -ForegroundColor Gray
    }
} #end function

"`nTest 1 | -Value with DOUBLE backticks" | Write-Host
Test $bFolder $subfA $null $txtFile $backtickD

"`nTest 2 | -Value with DOUBLE backticks + SUBFOLDER(B)" | Write-Host
Test $bFolder $subfA $subfB $txtFile $backtickD

"`nTest 3 | -Value with SINGLE backticks" | Write-Host
Test $bFolder $subfA $null $txtFile $backtickS

"`nTest 4 | -Value with SINGLE backticks + SUBFOLDER(B)" | Write-Host
Test $bFolder $subfA $subfB $txtFile $backtickS 


$PSVersionTable
pause

I guess this is related to https://github.com/PowerShell/PowerShell/issues/13136

[iSazonov]

I think this could be fixed with #13134

/cc @mklement0

[KaXaSA]

if Install the preview (v7.1.0-rc.1) does it fix the problem? or that wasn't implemented yet? (I will probably test it later)