Nulcleaner

English — Official English version of nulcleaner.

nulcleaner - Windows NUL File Cleanup

The Problem

When /dev/null is used in commands under Git Bash on Windows (e.g., > /dev/null), instead of redirecting to nowhere, an actual file named nul is created in the current directory. Windows reserves "NUL" as a device name, which means these files cannot be deleted normally.

This tool finds and deletes such NUL files via the extended UNC path (\\?\).

Modes

CLI Usage

# Scan only (shows found NUL files) (Deutsch)
python nulcleaner.py scan /path/to/directory

# Scan and delete (Deutsch)
python nulcleaner.py delete /path/to/directory

# Start GUI mode (Deutsch)
python nulcleaner.py gui

Headless API (for Integration)

The tool also provides a Python API for headless operation:

from nulcleaner import clean_nul_files_headless

result = clean_nul_files_headless("/path/to/directory", verbose=True)
print(f"Found: {result['found']}, Deleted: {result['deleted']}")

Return value: {'found': int, 'deleted': int, 'errors': list}

Technical Details

• Uses the extended UNC path (\\?\) to delete Windows-reserved filenames
• Recursive scan with os.walk()
• GUI with tkinter (no external dependencies)
• Only works on Windows (where the problem occurs)

Prevention

Best to avoid /dev/null in Git Bash altogether. Instead:

• Simply omit the output
• Use 2>&1 for stderr redirection
• Pay attention to Windows compatibility in shell scripts