Intelligent file write error handler: diagnoses permissions, disk space, path length, file locks before retrying. Use when you encounter 'Error writing file', 'Permission denied', 'Access denied', 'No space left', or related file write failures.
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tessl review fix ./bundled/skills/smart-file-writer/SKILL.mdAutomatically diagnoses and resolves file write errors through systematic investigation rather than blind retries. Prevents common write failures proactively.
Use this skill when any of these occurs:
This skill does NOT:
Required inputs:
1. Path Validation
import os
# Check path length (Windows: 260 char limit)
if len(filepath) > 260 and os.name == 'nt':
print(f"Path too long: {len(filepath)} chars")
# Check parent directory exists
parent = os.path.dirname(filepath)
if not os.path.exists(parent):
print(f"Parent directory missing: {parent}")2. Permission Check
import os
# Check directory write permission
parent = os.path.dirname(filepath) or '.'
if not os.access(parent, os.W_OK):
print(f"No write permission: {parent}")
# Check file permissions if exists
if os.path.exists(filepath):
if not os.access(filepath, os.W_OK):
print(f"File not writable: {filepath}")3. Disk Space Check
import shutil
# Check available disk space
stat = shutil.disk_usage(os.path.dirname(filepath) or '.')
free_gb = stat.free / (1024**3)
if free_gb < 0.1: # Less than 100MB
print(f"Low disk space: {free_gb:.2f} GB free")4. File Lock Detection
import os
# Try to open with exclusive access
try:
with open(filepath, 'a') as f:
pass
except PermissionError:
print(f"File locked by another process: {filepath}")5. Windows-Specific Checks
# Check if file is in use (Windows)
handle.exe -a "filepath"
# Check file attributes
attrib "filepath"Pattern 1: Create Missing Directories
import os
os.makedirs(os.path.dirname(filepath), exist_ok=True)Pattern 2: Atomic Write (Temp + Rename)
import os
import tempfile
# Write to temp file first
temp_fd, temp_path = tempfile.mkstemp(dir=os.path.dirname(filepath))
try:
with os.fdopen(temp_fd, 'w') as f:
f.write(content)
# Atomic rename
os.replace(temp_path, filepath)
except Exception as e:
os.unlink(temp_path)
raisePattern 3: Exponential Backoff for Transient Issues
import time
def write_with_retry(filepath, content, max_retries=3):
for attempt in range(max_retries):
try:
with open(filepath, 'w') as f:
f.write(content)
return True
except (PermissionError, OSError) as e:
if attempt < max_retries - 1:
wait = 2 ** attempt # 1s, 2s, 4s
time.sleep(wait)
else:
raisePattern 4: Alternative Path (Shorten Long Paths)
import os
import hashlib
def shorten_path(long_path):
"""Use hash for long filenames"""
dir_path = os.path.dirname(long_path)
filename = os.path.basename(long_path)
if len(long_path) > 260:
# Hash the filename
name, ext = os.path.splitext(filename)
hash_name = hashlib.md5(name.encode()).hexdigest()[:16]
return os.path.join(dir_path, f"{hash_name}{ext}")
return long_pathPattern 5: Permission Fix Suggestions
# Linux/Mac: Add write permission
chmod u+w filepath
# Windows: Remove read-only attribute
attrib -r filepath
# Windows: Take ownership (admin required)
takeown /f filepath
icacls filepath /grant %username%:FPattern 6: Detect Antivirus Interference
import time
import os
def is_antivirus_blocking(filepath):
"""Detect if antivirus is scanning file"""
try:
# Try to open exclusively
with open(filepath, 'r+b') as f:
pass
return False
except PermissionError:
# Wait and retry
time.sleep(0.5)
try:
with open(filepath, 'r+b') as f:
pass
return True # Was temporarily blocked
except:
return False # Persistent blockBefore Any Critical Write
def validate_write_conditions(filepath):
"""Run before writing important files"""
issues = []
# 1. Path length
if len(filepath) > 260 and os.name == 'nt':
issues.append(f"Path too long: {len(filepath)} chars")
# 2. Parent directory
parent = os.path.dirname(filepath) or '.'
if not os.path.exists(parent):
issues.append(f"Parent missing: {parent}")
elif not os.access(parent, os.W_OK):
issues.append(f"No write permission: {parent}")
# 3. Disk space
stat = shutil.disk_usage(parent)
if stat.free < 100 * 1024 * 1024: # 100MB
issues.append(f"Low disk space: {stat.free / 1024**2:.1f} MB")
# 4. File exists and writable
if os.path.exists(filepath):
if not os.access(filepath, os.W_OK):
issues.append(f"File not writable: {filepath}")
return issuesWrap Write Tool
# Before using Write tool, validate:
issues = validate_write_conditions(target_path)
if issues:
print("Pre-write validation failed:")
for issue in issues:
print(f" - {issue}")
# Take corrective action
else:
# Proceed with Write toolWrap Edit Tool
# Before editing, check file is writable
if not os.access(filepath, os.W_OK):
print(f"Cannot edit: {filepath} is read-only")
# Suggest: chmod u+w or attrib -rWrap Bash File Operations
# Before redirecting output
if [ ! -w "$(dirname "$output_file")" ]; then
echo "Cannot write to directory"
exit 1
fiInput:
Steps:
os.makedirs('results', exist_ok=True)Expected output:
Diagnosis: Parent directory 'results' does not exist
Resolution: Created directory 'results'
Retry: torch.save() succeededInput:
D:\very\long\path\with\many\subdirectories\...\extremely_long_filename_that_exceeds_windows_limit.csvSteps:
Expected output:
Warning: Path length 285 chars exceeds Windows limit (260)
Alternative: D:\very\long\path\...\a3f5e8b2c1d4.csv
Mapping saved to: path_mappings.json
Write succeeded to alternative pathInput:
Steps:
attrib -r data.csvExpected output:
Diagnosis: File 'data.csv' has read-only attribute
Resolution: Run 'attrib -r data.csv' to remove read-only flag
[After user confirmation]
Attribute removed. Retry succeeded.Input:
Steps:
Expected output:
Diagnosis: File 'report.xlsx' is locked by another process
Likely cause: File is open in Microsoft Excel
Resolution options:
1. Close Excel and retry
2. Write to alternative: 'report_new.xlsx'
3. Use atomic write with temp file
Cannot proceed automatically. User action required.Input:
Steps:
Expected output:
Warning: Insufficient disk space
Required: ~2.0 GB
Available: 0.5 GB
Recommendations:
1. Clean up temporary files
2. Write to alternative drive: E:\
3. Compress checkpoint before saving
Write operation blocked to prevent failure.references/diagnostic-procedures.md: Detailed diagnostic workflowsreferences/platform-specific.md: Windows/Linux/Mac specific issuesreferences/integration-guide.md: Integrating with Claude Code toolsreferences/error-catalog.md: Common error messages and solutionsddcaa2a
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