Enhanced File Removal Prevention in pre_tool_use Hook

[qdhenry]

Summary

This PR enhances the pre_tool_use.py hook to provide intelligent file removal prevention that allows safe operations within the current working directory while protecting system files.

Key Changes

1. Smart Deletion Logic

• Allows deletion of files/folders within the current working directory (CWD)
• Blocks deletion of protected system paths regardless of location
• Blocks deletion of files outside the CWD

2. New Helper Functions

• is_within_cwd(path) - Checks if a path is within the current working directory
• extract_target_paths(command) - Extracts all target paths from removal commands

3. Improved Pattern Detection

The hook detects various removal methods:

• Standard rm commands (with any flags)
• Directory removal (rmdir)
• Alternative deletion tools
• Move operations to trash locations
• Find commands with delete flags

4. Better Error Messages

• Clear indication when blocking protected system paths
• Clear indication when blocking paths outside CWD
• Shows current working directory for context

Configuration

Users can customize protected paths via the CLAUDE_PROTECTED_PATHS environment variable with colon-separated paths.

Testing

All scenarios tested successfully:

• ✅ Deletion within CWD - ALLOWED
• ✅ Deletion outside CWD - BLOCKED
• ✅ Deletion of protected paths - BLOCKED
• ✅ Clear error messages for each scenario

Impact

This change provides a better balance between safety and usability:

• Developers can work freely within their project directories
• System files remain protected
• Accidental deletions outside the current project are prevented

[qdhenry]

@disler , For context, I wanted to borrow this hook you published previously for a project I am working on. However, when I ran some tests, I realized Claude had snuck around the hook and moved the directory on my home path straight to the trash can using the mv command, so seeing that I wanted to add some additional guards to prevent this.

I'm super grateful for your YouTube channel and the projects you share, brother! Keep up the fantastic work!