powershell-fix
A host-layer plugin for DeepSeek Harness (DSH) that detects and auto-fixes Windows PowerShell command syntax mistakes before they burn a tool-call round-trip — then executes the corrected command through the host shell seam, under the normal sandbox/approval policy.
AI agents (and humans) frequently paste bash-flavored commands into a Windows terminal. This plugin gives the agent one tool — powershell_fix — that checks, repairs, and runs such commands safely.
What it fixes
Line hygiene (the most frequent real-world breakage)
| problem | fix |
|---|---|
CRLF / stray \r from copy-paste | normalized to LF |
pasted shell prompts (PS C:\> , C:\> , $ on every line) | stripped |
| trailing whitespace after a continuation char (invisible breakage) | removed |
bash \ line continuation | PowerShell backtick |
missing continuation before a -Parameter line | backtick inserted |
| dangling backtick before an empty line | removed |
| unbalanced quotes | warned (never blindly rewritten) |
bash → PowerShell semantics
| bash | PowerShell | |---|---| | export NAME=value | $env:NAME='value' (same-command $NAME refs rewritten to $env:NAME) | | unset NAME | if (Test-Path Env:NAME) { Remove-Item Env:NAME } (guarded; inline-in-chain supported) | | > /dev/null, 2> /dev/null, &> /dev/null | > $null, 2> $null, *> $null | | a && b / a || b | kept on PowerShell 7+; split into if ($?) { … } on Windows PowerShell 5.1 (engine auto-detected) | | ls -la path | Get-ChildItem path -Force | | rm -rf x | Remove-Item x -Recurse -Force | | mkdir -p a/b/c | New-Item -ItemType Directory -Force … | | touch f | timestamp update or New-Item -ItemType File | | grep [-r] [-v] pat f… | Select-String (recursion via Get-ChildItem -Recurse) | | which x / command -v x | (Get-Command x -ErrorAction SilentlyContinue).Source | | head -n N f / tail -n N f / tail -f f | Get-Content -TotalCount N / -Tail N / -Wait | | sed, awk, chmod, bare $PATH-style env refs | warned with PowerShell equivalents (never blindly rewritten) |
Correct PowerShell passes through unchanged (no-op guarantee, covered by regression tests). The fixer is idempotent: fix(fix(x)) === fix(x).
Safety
- Execution goes through the host
ctx.shellseam — the same sandbox, approval, and timeout policy as the built-in pwsh tool. This plugin adds no privilege. - A built-in execution gate refuses to auto-execute semantically destructive commands even after fixing them: root-target recursive deletes (
rm -rf /,Remove-Item C:\ -Recurse),Format-Volume,Clear-Disk,Set-ExecutionPolicy,del /s|/q, and environment/system persistence writes (setx,[Environment]::Set*,New-ItemProperty,Set-ItemProperty,reg add). execute: false(orautoExecute: falseconfig) gives a dry-run: fix only, no execution.
Install (host layer — available to every session)
The package declares dsh.bundle.patch, so installing it into a profile adds it to the profile's layer stack automatically — no agent-preset line needed:
dsh plugin --profile web add file:/path/to/powershell-fixReconciling notices the dsh.bundle declaration and appends powershell-fix to dsh.profile.bundles; the bundled cordis.patch.yml inserts the plugin row at the host layer. Restart the harness, and every session on that profile gets:
- tool
powershell_fix - a system-prompt section teaching native PowerShell syntax and when to call the tool
> Note: pnpm file: dependencies copy lib/*.js — after editing the source, delete node_modules/powershell-fix in the profile and re-run the add command ("Already up to date" is misleading).
Tool contract
// powershell_fix({ command, shell?, execute?, description? })
{
"ok": true,
"platform": "win32",
"shell": "powershell51", // auto-detected engine: pwsh | powershell51
"original": "export A=1 && echo $A",
"fixed": "$env:A='1'; if ($?) { echo $env:A }",
"changed": true,
"fixes": [{ "rule": "ENV_EXPORT", "notes": ["…"] }],
"warnings": [{ "rule": "BARE_VAR", "note": "…" }],
"execution": { "mode": "auto", "exitCode": 0, "stdout": "…", "stderr": "…" }
// execution.mode: auto | dry-run | skipped-dangerous | aborted
}Config (cordis row / dsh.bundle defaults): autoExecute (default true), timeoutMs (default 60000).
Development
Zero runtime dependencies (engine is pure JS); peer deps @deepseek-ai/dsh-tools and @deepseek-ai/schemastery resolve from the host.
node --test # unit tests (engine, 57 assertions)
node acceptance/mount_check.mjs <profile_web_dir> # mount + live-path check
node acceptance/real_pwsh_e2e.mjs # fixed commands executed by the real engine中文说明
DSH host 层插件:在 Windows 终端上自动检测并修复 PowerShell 命令语法错误(bash 语法、续行符错误、粘贴带入的提示符与 CRLF),修复后经宿主 shell 缝隙执行——沙箱/审批策略与内置 pwsh 工具完全一致,危险命令只修复不执行。声明 dsh.bundle.patch,装入 profile 即对所有会话生效,无需改任何 preset。
License
MIT