cleanup-nul

Original：🇺🇸 English

Translated

Find and delete 'nul' files accidentally created by tools on Windows. Use when cleaning up spurious nul files from a directory tree.

2installs

Sourcechenxizhang/agent-skills

Added on2026-03-04

NPX Install

npx skill4agent add chenxizhang/agent-skills cleanup-nul

SKILL.md Content

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Cleanup NUL Files

Find and remove

nul

files that are accidentally created by some tools (like Claude Code) on Windows.

Background

On Windows,

nul

is a reserved device name (like

/dev/null

on Unix). Some tools may accidentally create actual files named

nul

, which can cause issues. This skill helps locate and remove them.

Strict Execution Flow

Do NOT use any scripts. Do NOT skip or merge phases. Execute each phase in order.

Phase 1: Environment Detection (MANDATORY — must display results before proceeding)

Detect and explicitly display the following before doing anything else:

Operating System: Run a command to detect the OS.
- Windows:
```
[System.Environment]::OSVersion
```
  or
```
$env:OS
```
- macOS/Linux:
```
uname -s
```

Shell environment: Identify the current shell.

PowerShell:
```
$PSVersionTable.PSVersion
```

bash/zsh:

echo $SHELL

and

echo $BASH_VERSION

or

echo $ZSH_VERSION

Agent identity: Identify which agent is running this skill (Claude Code, GitHub Copilot CLI, Cursor, etc.) based on the agent's own context/identity.

Display the detection results clearly, for example:

Environment Detection:
  OS:    Windows 11 (10.0.22631)
  Shell: PowerShell 7.4
  Agent: GitHub Copilot CLI

All subsequent phases MUST use ONLY commands appropriate for the detected OS and shell. Never mix platform commands.

Phase 2: Plan (generate environment-specific steps)

Based on Phase 1 results, generate the concrete execution plan:

For PowerShell (Windows):

Find:

Get-ChildItem -Path <target> -Recurse -Filter "nul" -File -Force -ErrorAction SilentlyContinue

Delete:
```
Remove-Item -LiteralPath <file> -Force
```
(use
```
\\?\<full-path>
```
prefix if deletion fails due to reserved name)

For bash/zsh (macOS/Linux):

Find:

find <target> -name "nul" -type f 2>/dev/null

Delete:
```
rm -f <file>
```

For Git Bash on Windows:

Find:

find <target> -name "nul" -type f 2>/dev/null

Delete:
```
rm -f <file>
```
(if fails, note that PowerShell may be needed for reserved name handling)

Target path: user-specified or default to current working directory.

If scanning multiple separate root paths, plan them as parallel operations.

Phase 3: Execute

Run the find command from the plan
List all found
```
nul
```
files with their full paths
Report the total count
Ask the user for confirmation before deleting
Delete the confirmed files
Report results (deleted count, any failures)

Phase 4: Report & Recommendations

Summarize what was done and provide environment-specific recommendations:

Windows PowerShell: Recommend checking IDE/tool settings that may create
```
nul
```
files. Suggest using
```
Remove-Item -LiteralPath "\\?\..."
```
for stubborn files.
macOS/Linux bash: Note that
```
nul
```
files are uncommon on Unix — check if Windows-origin tools created them.
NEVER recommend commands from a different platform (e.g., do NOT suggest
```
chmod
```
on Windows, do NOT suggest
```
Get-Acl
```
on Linux).

cleanup-nul

NPX Install

Tags

SKILL.md Content

Cleanup NUL Files

Background

Strict Execution Flow

Phase 1: Environment Detection (MANDATORY — must display results before proceeding)

Phase 2: Plan (generate environment-specific steps)

Phase 3: Execute

Phase 4: Report & Recommendations