Surprising quoting behavior in wsl command from Windows

[Noratrieb]

Windows Version

Microsoft Windows [Version 10.0.19045.4412]

WSL Version

2.1.5.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

5.15.146.1

Distro Version

Ubuntu 22.04, Ubuntu 24.04

Other Software

No response

Repro Steps

In PowerShell:

$ wsl echo "a\a"
aa
$ wsl echo "a \a"
a\a

Expected Behavior

I expected consistent behavior wrt the escaping of the backslash. My user case was passing a Windows path to WSL (to be converted with wslpath and then used) and when the path didn't contain spaces, it didn't work correctly, and if it did contain spaces, it worked.

Actual Behavior

Consistent behavior, where the backslash is shown both times or never.

Diagnostic Logs

I wrote a quick Rust program to dump argv and set that as my shell.

In the first case, the shell's argv was [/path/to/executable, -c, echo a\a].
In the second case, it was [/path/to/executable, -c, echo "a \a"].
So it looks like wsl conditionally wraps the argument in quotes when it would be split by bash.

[github-actions]

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How to collect WSL logs

Download and execute collect-wsl-logs.ps1 in an administrative powershell prompt:

Invoke-WebRequest -UseBasicParsing "https://raw.githubusercontent.com/microsoft/WSL/master/diagnostics/collect-wsl-logs.ps1" -OutFile collect-wsl-logs.ps1
Set-ExecutionPolicy Bypass -Scope Process -Force
.\collect-wsl-logs.ps1

The scipt will output the path of the log file once done.

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View similar issues

Please view the issues below to see if they solve your problem, and if the issue describes your problem please consider closing this one and thumbs upping the other issue to help us prioritize it!

Closed similar issues:

• Command-line arguments to Windows exe - double quotes not passed as expected (#2411), similarity score: 0.73
• Command-line arguments to Windows exe not quoted when they contain tabs (#2164), similarity score: 0.73
• bash.exe no longer recognizes wsl command surrounded by single quotes. (#5932), similarity score: 0.72
• Cannot escape quotation mark in --cd argument of wsl.exe (#8712), similarity score: 0.71

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This issue has been automatically closed since it has not had any author activity for the past 7 days. If you're still experiencing this issue please re-file it as a new issue.

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