Claude defaults to bash/Unix syntax on Windows instead of PowerShell

[benf-innovatum]

Even when Claude Code is running on Windows and the platform is clearly identified as win32, the Claude model defaults to bash/Unix syntax for shell commands and Unix-style filesystem paths. This results in commands that don't work in PowerShell or CMD, and repeated failed attempts before the correct syntax is used.

Examples observed:

• Using /usr/local/bin/, /dev/null, and similar Unix paths on Windows
• Writing shell commands with bash syntax (heredocs, backtick substitution) instead of PowerShell equivalents
• Repeatedly retrying Bash tool calls after failures instead of adapting to the Windows environment

Expected: When the platform is win32, Claude should default to PowerShell-compatible syntax for shell commands and Windows-style paths, and should recognise when the Bash tool is unavailable and adapt accordingly.

Environment: Windows 10 Pro, Claude Code native

[HeyItsGilbert]

The way I've come to deal with this is to use a hook. I wrote a PowerShell module to make writing PowerShell based hooks easier: https://github.com/HeyItsGilbert/ClaudeHooks

https://gist.github.com/HeyItsGilbert/095f1f7dccbd59d8be677baa9c81a0e9 are some hooks I'm actively using. One to normalize paths to forward slash, since PowerShell can handle both. The other is to detect Bash() calls to known PowerShell equivalents (or other built-in tools). It'll allow it (in most cases), and let the LLM know, "Sir, this is a PowerShell. Use the PowerShell() tool." Makes me laugh each time, so at least I don't get too annoyed.

[HeyItsGilbert]

https://github.com/anthropics/claude-code/releases/tag/v2.1.126 may have fixed this BTW.

[github-actions]

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

[github-actions]

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