File Operation Safety

File Operation Safety

CRITICAL: File deletions can be permanent. This skill prevents irreversible file loss.

Danger Levels

Pre-Operation Protocol

Before ANY Deletion

Step 1: Verify the path

# ALWAYS expand and verify the path first
realpath /path/to/target
ls -la /path/to/target

# Check what's inside (for directories)
find /path/to/target -type f | wc -l  # Count files
du -sh /path/to/target                 # Check size

Step 2: Present impact to user

## File Deletion Impact Assessment

**Command:** rm -rf ./node_modules
**Resolved path:** /Users/dev/myproject/node_modules

**Contents:**
- Total files: 45,234
- Total directories: 8,901
- Total size: 234 MB
- Contains hidden files: Yes (.cache, .bin)

**Can be recreated:** Yes (via `npm install`)

Proceed with deletion? Type "yes, delete node_modules" to confirm.

For Critical Operations

rm -rf on Directory

⛔ **CRITICAL: RECURSIVE DELETE REQUESTED**

**Command:** rm -rf /var/www/myapp

**⚠️ FULL PATH CHECK:**
- Requested path: /var/www/myapp
- Resolved path: /var/www/myapp
- Parent directory: /var/www (contains 3 other directories)
- Is symlink: No

**Contents to be deleted:**
- Files: 1,234
- Directories: 89
- Size: 456 MB
- Includes:
  - Source code (*.js, *.ts): 234 files
  - Configuration (*.json, *.yml): 12 files
  - Environment files (.env): 1 file ⚠️
  - Uploaded files (uploads/): 567 files ⚠️

**Recovery:**
- Git repository: Yes (can recover source code)
- Uploads folder: NO GIT ⚠️ (not recoverable)
- .env file: NO GIT ⚠️ (not recoverable)

**Before deletion, I recommend:**
1. Backup uploads folder: `cp -r uploads /backup/uploads_$(date +%Y%m%d)`
2. Backup .env: `cp .env /backup/.env_$(date +%Y%m%d)`

Proceed with deletion after backup? Type "yes, delete /var/www/myapp after backup" to confirm.

rm on Home Directory or Root

⛔⛔⛔ **EXTREME DANGER: CATASTROPHIC PATH DETECTED**

**Command:** rm -rf ~/ (or /, /home, /usr, /etc, /var)

**🚫 I WILL NOT EXECUTE THIS COMMAND.**

This would delete:
- Your entire home directory
- All personal files, documents, and configurations
- SSH keys, credentials, and secrets
- Potentially your entire system

**This is almost certainly a mistake.**

If you need to clean up:
- Specify exact subdirectories to delete
- Use `rm -rf ~/specific/directory` instead
- Never use wildcards at root level

**I will not proceed with this request under any circumstances.**

rm with Wildcards

🔴 **DANGEROUS: WILDCARD DELETION**

**Command:** rm -rf *.log
**Working directory:** /var/log/myapp

**Files matching pattern:**
1. access.log (234 MB)
2. error.log (45 MB)
3. debug.log (12 MB)
4. app.2024-01-15.log (5 MB)
5. app.2024-01-14.log (4 MB)
... and 23 more files

**Total files:** 28
**Total size:** 345 MB

**Potential issues:**
- Pattern `*.log` is broad - verify these are all logs you want to delete
- Some may be needed for debugging recent issues
- Rotating logs may have important history

**Safer alternatives:**
```bash
# Delete only old logs
find . -name "*.log" -mtime +30 -delete

# Keep recent logs
rm -f *.log.2023*

Proceed with deleting all 28 .log files? Type "yes, delete 28 log files" to confirm.

### Moving Files (Overwrite Risk)

```markdown
## File Move Impact Assessment

**Command:** mv ./config.json ./backup/config.json

**⚠️ OVERWRITE WARNING:**
A file already exists at the destination!

**Source file:**
- Path: ./config.json
- Size: 2.3 KB
- Modified: 2024-01-16 14:30:00

**Destination file (WILL BE OVERWRITTEN):**
- Path: ./backup/config.json
- Size: 1.8 KB
- Modified: 2024-01-15 09:00:00

**Differences detected:** Yes (source is newer and larger)

**Options:**
1. Overwrite (lose old backup)
2. Rename destination first: `mv ./backup/config.json ./backup/config.json.old`
3. Use versioned name: `mv ./config.json ./backup/config.$(date +%Y%m%d).json`
4. Cancel

Choose an option or type "yes, overwrite backup/config.json" to proceed with overwrite.

Copying with Overwrite

## File Copy Impact Assessment

**Command:** cp -r ./src ./backup/src

**⚠️ DIRECTORY OVERWRITE WARNING:**
The destination directory already exists!

**Source directory:**
- Path: ./src
- Files: 234
- Size: 12 MB

**Destination directory (contents may be OVERWRITTEN):**
- Path: ./backup/src
- Files: 198
- Size: 10 MB
- Modified: 2024-01-14 16:00:00

**What will happen:**
- 198 existing files may be overwritten with newer versions
- 36 new files will be added
- 0 files in destination will be deleted (cp doesn't delete)

**Safer alternatives:**
```bash
# Create versioned backup
cp -r ./src ./backup/src_$(date +%Y%m%d_%H%M%S)

# Use rsync for smarter sync
rsync -av --backup --suffix=.bak ./src/ ./backup/src/

Choose approach or type "yes, overwrite backup/src" to proceed.

## Safe Patterns

### Safe Deletion with Confirmation

```bash
# Interactive deletion (asks for each file)
rm -i file1 file2 file3

# Show what would be deleted (dry run)
find /path -name "*.tmp" -print  # Preview
find /path -name "*.tmp" -delete # Execute after verification

# Move to trash instead of permanent delete
# macOS
mv file ~/.Trash/

# Linux (with trash-cli)
trash-put file

Safe Directory Cleanup

# Never use: rm -rf *
# Instead, be explicit:
rm -rf ./node_modules
rm -rf ./dist
rm -rf ./.cache

# Or use a list:
DIRS_TO_CLEAN="node_modules dist .cache"
for dir in $DIRS_TO_CLEAN; do
  echo "Deleting: $dir"
  rm -rf "./$dir"
done

Backup Before Risky Operations

# Create timestamped backup
BACKUP_DIR="./backups/$(date +%Y%m%d_%H%M%S)"
mkdir -p "$BACKUP_DIR"
cp -r ./important_folder "$BACKUP_DIR/"

# Then proceed with risky operation
rm -rf ./important_folder

Protection Mechanisms

Alias Safeguards (Add to .bashrc/.zshrc)

# Make rm interactive by default
alias rm='rm -i'

# Require verbose output for dangerous operations
alias rm='rm -iv'
alias mv='mv -iv'
alias cp='cp -iv'

# Prevent recursive operations on root
alias rm='rm --preserve-root'

# Add confirmation for rf
rmrf() {
  echo "⚠️ About to delete: $@"
  echo "Files: $(find "$@" -type f 2>/dev/null | wc -l)"
  read -p "Are you sure? (yes/no) " confirm
  if [ "$confirm" = "yes" ]; then
    rm -rf "$@"
  else
    echo "Aborted"
  fi
}

Safe Delete Function

# Safe delete with trash support
safe_delete() {
  local target="$1"
  local trash_dir="${HOME}/.local/share/Trash/files"

  if [ ! -e "$target" ]; then
    echo "Error: $target does not exist"
    return 1
  fi

  # Show what will be deleted
  echo "Target: $(realpath "$target")"
  if [ -d "$target" ]; then
    echo "Type: Directory"
    echo "Files: $(find "$target" -type f | wc -l)"
    echo "Size: $(du -sh "$target" | cut -f1)"
  else
    echo "Type: File"
    echo "Size: $(ls -lh "$target" | awk '{print $5}')"
  fi

  echo ""
  read -p "Move to trash? (yes/no) " confirm

  if [ "$confirm" = "yes" ]; then
    mkdir -p "$trash_dir"
    mv "$target" "$trash_dir/$(basename "$target").$(date +%s)"
    echo "Moved to trash. Recover from: $trash_dir"
  else
    echo "Aborted"
  fi
}

Common Dangerous Patterns to Block

Recovery Information

If Files Were Accidentally Deleted

# Check trash first (macOS/Linux with trash-cli)
ls ~/.Trash/           # macOS
ls ~/.local/share/Trash/files/  # Linux

# For recent deletions, check backup
ls ~/Dropbox/  # If using cloud backup
ls ~/.snapshots/  # If using Time Machine or snapshots

# For Git-tracked files
git checkout -- deleted_file
git restore deleted_file

# For untracked files in Git directory
# Unfortunately, mostly unrecoverable
# Prevention is the only cure

Best Practices Summary

Pre-Flight Checklist

Before any deletion:

• Path is verified with realpath or pwd
• Not in home directory, root, or system paths
• Contents previewed with ls or find
• Important files backed up
• Wildcard patterns tested with echo first
• Working directory confirmed
• Not running as root (unless absolutely necessary)