Powershell does not expand '~' for external programs

[xudyang1]

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

PS: ~ > pwsh --version
PowerShell 7.3.6
PS: ~ > cd .config/nvim
PS: .config/nvim > nvim ~/.bashrc # or code ~/.bashrc

• The last command opens an empty .bashrc file in current directory in neovim/vscode

Expected behavior

`~` should be expanded to `$HOME`

Actual behavior

pwsh does not expand `~` for external command

Error details

No response

Environment data

Name                           Value
----                           -----
PSVersion                      7.3.6
PSEdition                      Core
GitCommitId                    7.3.6
OS                             Microsoft Windows 10.0.19045
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Visuals

No response

[xudyang1]

The bug was previously discussed in #10675 and #11386 and was fixed by #12386, but version 7.3.6 breaks it again.

[237dmitry]

Could not be reproduced on either Windows (with the forward-slash path separator) or Linux. For testing used micro editor on both platforms.

# on Windows  (pwsh 7.3.6)
$ micro ~/Desktop/desktop.ini  # open
$ micro ~\Desktop\desktop.ini  # not open
Could not find user: user: unknown user \Desktop\desktop.ini

Press enter to continue

# on Linux (pwsh 7.4.0-preview.4)
$ micro ~/.bashrc  # open

[xudyang1]

Did you type <Tab> to expand the path manually? <Tab> works, but the literal string ~/../file does not work without <Tab>.

I even tested them (string, non-string, forward-slash, backslash) with an empty $PROFILE in pwsh, none of them worked.

[xudyang1]

I downloaded pwsh from Microsoft Store. Is it possible that the bug only appears in the store version?

[237dmitry]

Just tried in other editor (internal Far manager's editor far -e ) and behavior as in your issue. I think micro itself parses the filepath. That's why it works. And your issue is right.

[mklement0]

@xudyang1, you pointed to the relevant issues, but the behavior isn't broken; rather, on Windows ~ expansion was never officially implemented.

• Support passing PSPath to native commands #12386 implemented an experimental feature (PSNativePSPathResolution), which, after the discussion in Bypassing translation of PSDrive-based path arguments for external (native) executables is obscure and inadequate (PSNativePSPathResolution) #13644, was removed (Revert "Change PSNativePSPathResolution to not be Experimental" #13734)
• You can still enable the experimental feature up to PowerShell 7.2.x, but it is no longer present since v7.3

However, the ship hasn't fully sailed yet, given @SteveL-MSFT's comment here:

maybe someone can take my PR and address the edge cases in the future

---

For now:

• Only on Unix do you get ~ expansion, namely if the ~ is _unquoted and followed by / (notably, this means that something like ~<username> to refer to a given user's home dir. is not supported - see Implement ~username expansion on Windows and Linux #12387)

• On Windows, ~ expansion is not implemented (nor is automatic globbing, though the latter sensibly so).

---

Note that the scope of #12386 was larger than just ~ expansion: It tried to automatically convert paths based on PowerShell drives to file system-native drives, given that native (external) utilities don't know about PowerShell drives; e.g. temp:/foo.txt would be converted to C:\Users\jdoe\AppData\Local\Temp\foo.txt

If done robustly - and fully doing so is ultimately impossible - PowerShell on Unix would benefit from this conversion too.

It's also worth noting that the never-introduced implementation in #12386 handled ~ on Windows differently than the already-implemented ~ expansion on Unix:

• Unlike the Unix implementation, ~ inside "..." was - surprisingly also expanded (only '...' quoting prevented the expansion).
• E.g., ~ in cmd /c echo "~" was expanded on Windows, whereas /bin/echo "~" on Unix is not.

[xudyang1]

Thanks for the very detailed information! The ~ expansion in Windows should be a feature request instead of a bug.

[rkeithhill]

The Engine WG reviewed this issue today. As @mklement0 notes above, the original PSNativePathResolution experimental feature, which implemented ~ expansion for native apps on WIndows, had a number of issues that resulted in it being removed. Good news is that there is a PR to bring back this support on Windows (~ expansion for native apps is already available on Linux and macOS).